bluuebunny/crossref_metadata_2025 huggingface dataset:
Zinc and Cadmium Complexes of a Plant Metallothionein under Radical Stress: Desulfurisation Reactions Associated with the Formation of trans‐Lipids in Model Membranes
Authors: Torreggiani Armida , Domènech Jordi , Orihuela Ruben , Ferreri Carla , Atrian Sílvia , Capdevila Mercè , Chatgilialoglu Chryssostomos
Published: May 2009

Biomimetic tandem protein/lipid damage: The reactions of reductive reactive species, produced by γ irradiation of water, with Zn and Cd complexes of a metallothionein from a plant afford diffusible sulfur‐centred radicals generated from methionine residues and sulfide ligands. These species migrate from the aqueous phase to the lipid bilayer and transform the cis double bond of the oleate moiety to trans isomer (see scheme).

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Metallothioneins (MTs) are sulfur‐rich proteins capable of binding metal ions to give metal clusters. The metal–MT aggregates used in this work were Zn– and Cd–QsMT, where QsMT is an MT from the plant Quercus suber. Reactions of reductive reactive species (H. atoms and eaq−), produced by γ irradiation of water, with Zn– and Cd–QsMT were carried out in both aqueous solutions and vesicle suspensions, and were characterized by different approaches. By using a biomimetic model based on unsaturated lipid vesicle suspensions, the occurrence of tandem protein/lipid damage was shown. The reactions of reductive reactive species with methionine residues and/or sulfur‐containing ligands afford diffusible sulfur‐centred radicals, which migrate from the aqueous phase to the lipid bilayer and transform the cis double bond of the oleate moiety into the trans isomer. Tailored experiments allowed the reaction mechanism to be elucidated in some detail. The formation of sulfur‐centred radicals is accompanied by the modification of the metal–QsMT complexes, which were monitored by various spectroscopic and spectrometric techniques (Raman, CD, and ESI‐MS). Attack of the H. atom and eaq− on the metal–QsMT aggregates can induce significant structural changes such as partial deconstruction and/or rearrangement of the metal clusters and breaking of the protein backbone. Substantial differences were observed in the behaviour of the Zn– and Cd–QsMT aggregates towards the reactive species, depending on the different folding of the polypeptide in these two cases.
Total Synthesis of the Aspercyclides
Authors: Pospíšil Jiří , Müller Christoph , Fürstner Alois
Published: May 2009

Disparate sister compounds: Despite their similarity, significantly different strategies were necessary to bring the individual members of the aspercyclide family into reach. Whereas the strained eleven‐membered ring of aspercyclide C (see figure) could be closed by RCM, it required the power of organochromium chemistry (Nozaki–Hiyama–Kishi reaction) to forge the frame of its sterically even more hindered congener aspercyclide B.

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Two different approaches to the eleven‐membered biaryl ether lactones of the aspercyclide family are disclosed. The core regions of these highly strained targets, which are able to interfere with the binding of immunoglobulin E to its high affinity receptor, can either be forged by ring‐closing olefin metathesis (RCM) or by a highly diastereoselective chromium‐mediated Nozaki–Hiyama–Kishi (NHK) reaction. Whereas the RCM approach turned out to be responsive to minor changes in the substitution pattern of the substrate, the NHK route is more generally applicable. The preparation of the required cyclization precursor 43 hinged on a palladium‐catalyzed ortho‐iodination reaction of 2‐methylbenzoic acid, an efficient copper‐catalyzed Ullmann coupling, and a Takai–Utimoto olefination as the key steps. Moreover, the esterification of the 2,6‐disubstituted benzoic acid 34 with the sterically hindered secondary alcohol 37 was far from trivial. However, this and related transformations were accomplished by recourse to the corresponding acid fluorides, which provided excellent yields in cases in which the more commonly used acid chlorides or mixed anhydrides failed to afford any of the desired products.
Facile and Efficient Enantioselective Strecker Reaction of Ketimines by Chiral Sodium Phosphate
Authors: Shen Ke , Liu Xiaohua , Cai Yunfei , Lin Lili , Feng Xiaoming
Published: May 2009

Asymmetric catalysis: A facile enantioselective Strecker reaction of ketimines with trimethylsilyl cyanide (TMSCN) was realized by employing chiral (S)‐BNPNa 3 e and PBAP as an additive (see image). A wide substrate scope and good‐to‐excellent enantioselectivities were achieved.

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A facile and efficient enantioselective Strecker reaction of ketimines catalyzed by a chiral alkali‐metal salt has been developed. When 10 mol % BNPNa (BNP=1,1′‐binaphthyl‐2,2′‐diylphosphate) prepared in situ and 10 mol % para‐tert‐butyl‐ortho‐adamantylphenol (PBAP) were introduced into the reaction, up to 96 % yield and up to 95 % ee (ee=enantiomeric excess) were obtained. Both aliphatic and aromatic ketimines, especially sterically bulky cyclic ketimines derived from β‐acetonaphthone, α‐indanone, and α‐tetralone were found suitable for this reaction. On the basis of the experimental results and previous reports, trimethylsilyl cyanide (TMSCN) was indicated to be the real reactive nucleophile despite the existence of PBAP, and a possible working model was proposed to explain the origin of the asymmetric induction. The facile availability of 1,1′‐binaphthyl‐2,2′‐diylphosphoric acid (BNPH) and the simplicity of the procedure are beneficial for practical applications.
Chiral 1,1′‐binaphthylazepine‐derived amino alcohol catalyzed asymmetric aryl transfer reactions with boroxine as aryl source
Authors: Liu Can , Guo Zong‐Liang , Weng Jiang , Lu Gui , Chan Albert S. C.
Published: May 2009

Using chiral 1,1′‐binaphthylazepine‐derived amino alcohol as catalyst, the direct addition of in situ prepared arylzinc (with triphenylboroxine as aryl source) to various aryl aldehydes can afford optically active diarylmethanols in high yields and enantioselectivities (up to 96%). Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Integration of metabolomics and in vitro metabolism assays for investigating the stereoselective transformation of triadimefon in rainbow trout
Authors: Kenneke John F. , Ekman Drew R. , Mazur Chris S. , Konwick Brad J. , Fisk Aaron T. , Avants Jimmy K. , Garrison A. Wayne
Published: May 2009

Triadimefon is a systemic agricultural fungicide of the triazole class whose major metabolite, triadimenol, also a commercial fungicide, provides the majority of the actual fungicidal activity, i.e., inhibition of steroid demethylation. Both chemicals are chiral: triadimefon has one chiral center with two enantiomers while its enzymatic reduction to triadimenol produces a second chiral center and two diastereomers with two enantiomers each. All six stereoisomers of the two fungicides were separated from each other using a chiral BGB‐172 column on a GC‐MS system so as to follow stereospecificity in metabolism by rainbow trout hepatic microsomes. In these microsomes the S‐(+) enantiomer of triadimefon was transformed to triadimenol 27% faster than the R‐(−) enantiomer, forming the four triadimenol stereoisomers at rates different from each other. The most fungi‐toxic stereoisomer (1S,2R) was produced at the slowest rate; it was detectable after 8 h, but below the level of method quantitation. The triadimenol stereoisomer ratio pattern produced by the trout microsomes was very different from that of the commercial triadimenol standard, in which the most rat‐toxic pair of enantiomers (known as “Diastereomer A”) is about 85% of the total stereoisomer composition. The trout microsomes produced only about 4% of “Diastereomer A”. Complementary metabolomic studies with NMR showed that exposure of the separate triadimefon enantiomers and the racemate to rainbow trout for 48 h resulted in different metabolic profiles in the trout liver extracts, i.e., different endogenous metabolite patterns that indicated differences in effects of the two enantiomers. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
The roles of actin cytoskeleton and microtubules for membrane recycling of a food vacuole in Tetrahymena thermophila
Authors: Sugita Maki , Nakano Kentaro , Sato Mayuko , Toyooka Kiminori , Numata Osamu
Published: May 2009

Phagocytosis is a fundamental cellular event for the uptake of nutrients from the environment in several kinds of eukaryote. Most ciliates egest waste and undigested materials in food vacuoles (FVs) through a cytoproct, which is a specific organelle for defecation. It is considered that FV egestion is initiated by fusion between the FV membrane and plasma membrane in a cytoproct and completed with retrieval of the membrane into a cytoplasmic space. In addition, electron microscopy indicated that microfilaments might be involved in the recycling process of the FV membrane in ciliates over 30 years ago; however, there is no conclusive evidence. Here we demonstrated actin organization on FV near a cytoproct in Tetrahymena thermophila by using a marker for a cytoproct. Moreover, it was revealed that cells treated with actin cytoskeletal inhibitor, Latrunculin B, might be suppressed for membrane retrieval in a cytoproct following FV egestion. On the other hand, the actin structures, likely to be the site of membrane retrieval, were frequently observed in the cells treated with cytoplasmic microtubules inhibitor, Nocodazole. We concluded that actin filaments were probably required for recycling of the FV membrane in a cytoproct although the role was not essential for FV egestion. In addition, it was possible that microtubules might be involved in transportation of recycling vesicles of FV coated with F‐actin. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Discovery of a Potent, CNS‐Penetrant Orexin Receptor Antagonist Based on an N,N‐Disubstituted‐1,4‐diazepane Scaffold that Promotes Sleep in Rats
Authors: Whitman David B. , Cox Christopher D. , Breslin Michael J. , Brashear Karen M. , Schreier John D. , Bogusky Michael J. , Bednar Rodney A. , Lemaire Wei , Bruno Joseph G. , Hartman George D. , Reiss Duane R. , Harrell C. Meacham , Kraus Richard L. , Li Yuxing , Garson Susan L. , Doran Scott M. , Prueksaritanont Thomayant , Li Chunze , Winrow Christopher J. , Koblan Kenneth S. , Renger John J. , Coleman Paul J.
Published: May 2009

Silent Night: Antagonism of the orexin (or hypocretin) system has recently been identified as a novel mechanism for the treatment of insomnia. Herein, we describe discovery of a dual (OX1R/OX2R) orexin receptor antagonist featuring a 1,4‐diazepane central constraint that blocks orexin signaling in vivo. In telemetry‐implanted rats, oral administration of this antagonist produced a decrease in wakefulness, while increasing REM and non‐REM sleep.

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Statement on human papillomavirus DNA test utilization
Authors: Solomon Diane , Papillo Jacalyn L. , Davey Diane D.
Published: May 2009

This statement summarizes the expanded role of human papillomavirus (HPV) testing in the screening and management of cervical cancer. It also highlights circumstances in which HPV testing is not appropriate and may lead to overtreatment.
Filter digital form of two future temperature methods for the inverse heat conduction: A spectral comparison
Authors: Cabeza José María Gutiérrez , García Juan Andrés Martín , Rodríguez Alfonso Corz
Published: May 2009

Sequential methods that use future times in order to solve an inverse heat conduction problem can be re‐formulated as a sequential digital filter algorithm. The aim of this paper is to explore the filter effect of the function specification method and the truncated singular value decomposition method, in a sequential form. For this purpose, the power spectral densities of the corresponding filter coefficients are evaluated and it is shown that they act as band‐pass filter. Three numerical tests with different frequency spectra are considered in order to solve a linear one‐dimensional transient inverse problem. Furthermore, three models of crescent complexity are used in each method. It is shown that both methods provide similar results and in most cases, the optimum estimations require the same number of future times. As it is expected, similar estimations correspond to a similar band‐pass filter. The effect of the number of future times, the influence of the frequency spectrum of the input and the complexity of the model used can be clearly interpreted in the spectral space. The most complex models act as a highly selective band‐pass filter, but they require greater number of future times. Copyright © 2008 John Wiley & Sons, Ltd.
On the solution of the nonlinear Korteweg–de Vries equation by the homotopy perturbation method
Authors: Yildirim Ahmet
Published: May 2009

In this paper, the homotopy perturbation method is used to implement the nonlinear Korteweg–de Vries equation. The analytical solution of the equation is calculated in the form of a convergent power series with easily computable components. A suitable choice of an initial solution can lead to the needed exact solution by a few iterations. Copyright © 2008 John Wiley & Sons, Ltd.
What Far‐Infrared Spectra Can Contribute to the Development of Force Fields for Ionic Liquids Used in Molecular Dynamics Simulations
Authors: Köddermann Thorsten , Fumino Koichi , Ludwig Ralf , Canongia Lopes José N. , Pádua Agílio A. H.
Published: May 2009

Symbiosis: Far‐infrared spectra can be used to check the quality of force fields for molecular dynamics simulations of ionic liquids. On the other hand, MD simulations can explain the molecular basis of measured properties for this new liquid material (see picture).

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Palladium Catalysts Supported on Mesoporous Molecular Sieves Bearing Nitrogen Donor Groups: Preparation and Use in Heck and Suzuki CC Bond‐Forming Reactions
Authors: Demel Jan , Lamač Martin , Čejka Jiří , Štěpnička Petr
Published: May 2009

Best pals: Catalysts prepared from palladium(II) acetate and SBA‐15‐type mesoporous molecular sieves bearing SiCH2CH2CH2NHCH2CH2NEt2groups at the surface efficiently catalyze the Suzuki and Heck reactions. In the former reaction, the highly metalated catalysts prove to be more efficient while the influence of the metal loading in the latter is more complex: A catalyst with a very low metal loading is particularly attractive, being highly active, recyclable, and applicable as a bifunctional catalyst.

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A series of supported catalysts is prepared by treatment of SBA‐15‐type mesoporous molecular sieve bearing SiCH2CH2CH2NHCH2CH2NEt2groups with palladium(II) acetate. These catalysts are studied in Suzuki biaryl couplings and in Heck reactions to establish the influence of metal loading and innocent surface modifications (trimethylsilylation). The Suzuki reaction proceeded efficiently with model and practically relevant substrates; the catalyst performance increasing with an increasing degree of metalation (decreasing N/Pd ratio). Catalyst poisoning tests revealed that the reaction takes place in the liquid phase with the catalyst serving as a reservoir of active metal species and also as a stabilizing support once the reaction is performed. In the Heck reactions, on the other hand, the catalyst performance strongly changed with the reaction temperature and with the N/Pd ratio. The material with the lowest metal loading (0.01 mmol palladium per gram of material, N/Pd ratio ca. 100:1) proved particularly attractive in the Heck coupling, being highly active at elevated temperatures, recyclable, and capable of acting as a bifunctional catalyst (i.e., functioning without any external base.
Strategic Choices for Global Energy: Constraints from Feedbacks in the Climate System
Authors: Anderson James G.
Published: May 2009

The climate system itself provides feedback on the current state of pollution levels through several markers. With ever‐rising population numbers and energy demand, what should guide us when transforming our society into one that develops in a sustainable manner?

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Putting Science to Work in Developing a Climate Policy
Authors: Cicerone Ralph J.
Published: May 2009

The National Academy of Sciences is an honorific society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. This Viewpoint explores the interconnection between scientific research and policy making in developing a climate policy.

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Deploying a voice capture sensor network system for a secure ubiquitous home environment
Authors: Palafox Luis E. , García‐Macías J. Antonio
Published: May 2009

In this paper we present a novel voice capture sensor network architecture proposal, we detail the implementation procedure that we followed to build a working prototype. The prototype is oriented toward a secure ubiquitous home environment but can be extended to other similar scenarios. Our approach is based on reducing data redundancy while maintaining node redundancy for reliability and providing at the same time basic security services without sacrificing a considerable amount of resources. We further show that our approach is energy‐efficient compared with the capture–send approach used traditionally. More importantly, through our experiences in the real‐world deployment of the system we also provide a roadmap for the development of efficient voice‐based smart home applications. Copyright © 2009 John Wiley & Sons, Ltd.
Mesendodermal signals required for otic induction: Bmp‐antagonists cooperate with Fgf and can facilitate formation of ectopic otic tissue
Authors: Kwon Hye‐Joo , Riley Bruce B.
Published: May 2009

Induction of otic placodes requires Fgf from surrounding tissues. We tested the hypothesis that mesendodermally derived Bmp‐antagonists Chordin, Follistatin‐a, and Crossveinless‐2 cooperate in this process. Injecting morpholinos for all three genes, or treatment with the Nodal inhibitor SB431542 to block mesoderm‐formation, reduces otic induction and strongly enhances the effects of disrupting fgf3 or fgf8. In contrast, using a lower dose of SB431542, combined with partial loss of Fgf, causes a dramatic medial expansion of otic tissue and formation of a single, large otic vesicle spanning the width of the hindbrain. Under these conditions, paraxial cephalic mesoderm forms ectopically at the midline, migrates into the head, and later transfates to form otic tissue beneath the hindbrain. Blocking expression of Bmp‐antagonists blocks formation of medial otic tissue. These data show the importance of mesendodermal Bmp‐antagonists for otic induction and that paraxial cephalic mesendoderm can facilitate its own otic differentiation under certain circumstances. Developmental Dynamics 238:1582–1594, 2009. © 2009 Wiley‐Liss, Inc.
Patterns of muscular strain in the embryonic heart wall
Authors: Damon Brooke J. , Rémond Mathieu C. , Bigelow Michael R. , Trusk Thomas C. , Xie Wenjie , Perucchio Renato , Sedmera David , Denslow Stewart , Thompson Robert P.
Published: May 2009

The hypothesis that inner layers of contracting muscular tubes undergo greater strain than concentric outer layers was tested by numerical modeling and by confocal microscopy of strain within the wall of the early chick heart. We modeled the looped heart as a thin muscular shell surrounding an inner layer of sponge‐like trabeculae by two methods: calculation within a two‐dimensional three‐variable lumped model and simulated expansion of a three‐dimensional, four‐layer mesh of finite elements. Analysis of both models, and correlative microscopy of chamber dimensions, sarcomere spacing, and membrane leaks, indicate a gradient of strain decreasing across the wall from highest strain along inner layers. Prediction of wall thickening during expansion was confirmed by ultrasonography of beating hearts. Degree of stretch determined by radial position may thus contribute to observed patterns of regional myocardial conditioning and slowed proliferation, as well as to the morphogenesis of ventricular trabeculae and conduction fascicles. Developmental Dynamics 238:1535–1546, 2009. © 2009 Wiley‐Liss, Inc.
FuRMAS: triggering myoblast fusion in Drosophila
Authors: Önel Susanne‐Filiz , Renkawitz‐Pohl Renate
Published: May 2009

In Drosophila, as in mammals, myoblast fusion is fundamental for development. This fusion process has two distinct phases that share common ultrastructural features and at least some molecular players between Drosophila and vertebrates. Here, we integrate the latest data on the key molecular players and ultrastructural features found during myoblast fusion into a new working model to explain this fundamental cellular process. At cell–cell contact sites, a protein complex (FuRMAS) serves as a signalling centre and might restrict the area of membrane fusion. The FuRMAS consists of a ring of cell adhesion molecules, signalling proteins, and F‐actin. Regulated F‐actin branching plays a pivotal role in myoblast fusion with regard to vesicle transport, fusion pore formation, and expansion as well as the integration of the fusion‐competent myoblast into the growing myotube. Interestingly, local F‐actin accumulation is a typical feature of other transient adhesive structures such as the immunological synapse, podosomes, and invadopodia. Developmental Dynamics 238:1513–1525, 2009. © 2009 Wiley‐Liss, Inc.
Activator‐Controlled High Temperature In‐Situ Ligand Synthesis for the Formation of Rare Earth Thiolate Amide Coordination Polymers
Authors: Zurawski Alexander , Wirnhier Eva , Müller‐Buschbaum Klaus
Published: May 2009

1D rare earth thiolate amide coordination polymers can be obtained by an activator‐controlled in situ ligand synthesis in reactions of molten 2‐mercaptobenzimidazole with lanthanide metals. Catalytic amounts of mercury activate the metals and induce a C–S bond cleavage that in situ forms 2,2′‐bibenzimidazole. The latter then reacts as a linker ligand to give 1∞[Ln2(Mbim)4(Bbim)], Mbim– = C7H5SN2–, Bbim2–, C14N4H82–. In addition cinnabar is formed. Stoichiometric amounts of mercury cause the complete transformation of 2‐mercaptobenzimidazole to 2,2′‐bibenzimidazole. Instead of thiolate coordination polymers the reaction then yields sulfur‐free monomeric bibenzimidazolate complexes (BimH2)+[Ln(BbimH)4]–, (BimH2)+ = C7H6N2+, BbimH– = C14N4H9–. Thus the amount of Hg also controls the dimensionality of the products by defining the reaction path.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Transannular Ring Closure of a 1,8‐Diazacyclotetradeca‐3,5,10,12‐tetrayne to a Tricyclic System with a Central Cyclooctatetraene Ring
Authors: Gleiter Rolf , Hövermann Kirstin , Esser Birgit , Bandyopadhyay Arkasish
Published: May 2009

The addition of two equivalents of hydrochloric acid to N,N′‐diisopropyl‐1,8‐diazacyclotetradeca‐3,5,10,12‐tetrayne (13) afforded a tricyclic scaffold in which a central dichloro‐substituted cyclooctatetraene ring is annelated by two N‐isopropyl‐2,5‐dihydropyrrole rings (14). Three other minor products were congeners of 14 in which one (15, 16) or both (17) of the 2,5‐dihydropyrrole rings are oxidized. In 16 the chlorine atoms adopt different positions.The assignment of the structures of 14–17 is based on the result of an X‐ray investigation on single crystals of 16 and NMR studies. The structural assignments of 14 and 15 were corroborated by labeling experiments with DCl. The regiochemistry in the addition of the second equivalent of hydrochloric acid to 13 was illuminated by DFT calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Microwave‐Assisted Conversion of 4‐Nitrophenyl Esters into O‐Protected Hydroxamic Acids
Authors: Kurz Thomas , Pein Miriam K. , Marek Linda , Behrendt Christoph T. , Spanier Lukas , Kuna Krystina , Brücher Karin
Published: May 2009

The microwave‐assisted synthesis of O‐protected hydroxamic acids starting from 4‐nitrophenyl esters and O‐protected hydroxylamines is described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Telescoped Enolate Arylation/HWE Procedure for the Preparation of 3‐Alkenyl‐Oxindoles: The First Synthesis of Soulieotine
Authors: Millemaggi Alessia , Perry Alexis , Whitwood Adrian C. , Taylor Richard J. K.
Published: May 2009

A telescoped sequence involving palladium‐catalysed intramolecular enolate arylation followed by an in situ HWE olefination has been developed to provide rapid access to 3‐alkenyl‐oxindoles. This “one‐pot” process, which is greatly accelerated by microwave irradiation, proceeds with low loadings of palladium(II) acetate (0.2–1.0 mol‐%), and has been used to prepare a range of adducts derived from aromatic, heteroaromatic and aliphatic aldehydes as well as formaldehyde. In addition, further elaboration of the formaldehyde adducts are described. The applicability of the process has been established by carrying out the first synthesis of Soulieotine, a constituent of a traditional Chinese medicine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Electrochemical Preparation, Characterization, and Electrocatalytic Properties of OsPtCl6 Film Electrodes Towards Reduction of NAD+, Chloroacetic Acids, and Nitrous Oxide
Authors: Chen Shen‐Ming , Li Sheh‐Hung , Thangamuthu R.
Published: May 2009

Stable electroactive mixed films of osmium oxide/hexachloroplatinate, osmium oxide and platinum have been deposited on different electrode materials by cycling the electrode potential repetitively in solution containing Os3+ and PtCl$\rm{ {_{6}^{2-}}}$. The film growth of was monitored by using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The cyclic voltammetric features of modified electrode in Os3+ solution resembles that of surface wave, and involves ions‐exchange with Os3+ ions present in the solution. Based on the SEM results the modifier was considered as one‐dimensional, mixed‐valent polymeric film, and stabilized by Os3+/2+ counter ions. Finally, the electrocatalytic activity of the modified electrode was examined toward reduction of NAD+, chloroacetic acids and nitrous oxide.
Amperometric Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized on Fe3O4/Chitosan Modified Glassy Carbon Electrode
Authors: Tan Xuecai , Zhang Jinlei , Tan Shengwei , Zhao Dandan , Huang Zenwei , Mi Yan , Huang Zaiyin
Published: May 2009

A new type of amperometric hydrogen peroxide biosensor was constructed based on horseradish peroxidase (HRP) immobilized on Fe3O4/chitosan modified glassy carbon electrode. The effects of some experimental variables such as the concentration of supporting electrolyte, pH, enzyme loading, the concentration of the mediator of methylene blue (MB) and the applied potential were investigated. The linear range of the calibration curve for H2O2 was 2.0×10−4–1.2×10−2 M with a detection limit of 1.0×10−4 M (S/N=3). The response time was less than 12 s. The apparent Michaelis‐Menten constant Km was 21.4 mM and it illustrated the excellent biological activity of the fixed enzyme. In addition, the biosensor had long‐time stability and good reproducibility. And this method has been used to determine H2O2 concentration in the real sample.
Prediction of transmission‐line rating based on thermal overload probability using weather models
Authors: Kim Dong‐Min , Kim Jin‐O
Published: May 2009

This paper explains the concept of dynamic line rating (DLR) and suggests the method to forecast the thermal rating. The weather parameters are modeled corresponding to each transmission line, and thermal overload probability (TOP) is estimated using the predicted weather models and the present DLR value. In particular, a statistical wind speed model is developed using time series with compensation. In the case study, it is confirmed that the predicted TOP should be utilized as the criterion that decides forecast rating (FR) in order to operate the transmission line reasonably. The proposed method would be useful to enhance security and reliability of the transmission line. Moreover, this study could provide a better insight into the system operation and control, especially now a days when deregulation and liberalization of transmission systems are introduced. Copyright © 2009 John Wiley & Sons, Ltd.
High performance reactive control for unbalanced three‐phase load
Authors: Ghaeb Jasim A. , Aloquili Osama M.
Published: May 2009

In this paper we consider the problem of balancing a three‐phase load and how to optimize the TCR operation. For an unbalanced load change a VAT technique is developed by the authors to determine the three compensating susceptance values and then the unsymmetrical firing angles of TCR, which are necessary for a balanced load operation. An objective function (THD) is determined to measure the discontinuity of the TCR operation. For an unbalanced load change, the availability of TSC and the control of TCR produce different values of reactive volt–amperes, in which all produce the balanced operation but with different amounts of harmonics. The paper introduces and develops an iterative algorithm to obtain the optimum firing angle values of TCR, and this is based on minimum generation of harmonics. The results show that a modulated THD is achieved, and this approach guarantees the high performance reactive control for unbalanced three‐phase load. Copyright © 2009 John Wiley & Sons, Ltd.
Full‐scale study on combustion characteristics of an upholstered chair under different boundary conditions—Part 1: Ignition at the seat center
Authors: Xie Q. Y. , Zhang H. P. , Han Z. F. , Mei P.
Published: May 2009

The objective of this work is to investigate the effects of boundary conditions on the combustion characteristic of combustible items in a room. A series of full‐scale experiments were carried out in the ISO 9705 fire test room with an upholstered chair at four typical locations, i.e. at the middle of side wall, at the center of the room with the seat toward the door, at the center of the room with the seat toward inside of the room, at the room corner, respectively. Ignition was achieved through a BS No.7 wooden crib at the geometric center of the seat surface for each test. Besides the heat release rate (HRR), four thermocouple trees were placed around the chair to monitor detailed temperature distributions during the combustion process of an upholstered chair. The results indicated that the boundary conditions had some effects on the combustion behavior of a chair in a room. It was shown that there were clearly two main peak HRRs for the cases of a chair being clung to the side wall or at the corner. However, there was only one main peak HRR when the chair was placed at the center of the room, either outwards or inwards. In addition, the results of the two cases of chairs being at the center indicate that the maximum HRR (about 829 kW) for the chair seat toward the door was relatively larger than the maximum HRR (about 641 kW) for the chair seat toward inside of the room. It was suggested that the special complex structure of a chair was also a considerable factor for the effect of boundary conditions on the combustion behavior of a chair in an enclosure. Furthermore, the measured temperature distributions around the chair also illustrated the effects of boundary condition on the combustion behavior of a chair in a room. It was suggested that although HRR was one of the most important fire parameters, HRR mainly represented the comprehensive fire behavior of a combustible item. In order to develop more suitable room fire dynamic models, more detailed information such as the surrounding temperature distributions measured by the thermocouple trees are useful. Copyright © 2009 John Wiley & Sons, Ltd.
A2E, a component of lipofuscin, is pro‐angiogenic in vivo
Authors: Iriyama Aya , Inoue Yuji , Takahashi Hidenori , Tamaki Yasuhiro , Jang Woo‐Dong , Yanagi Yasuo
Published: May 2009

A recent study in vitro demonstrated that a major lipofuscin component, A2E, serves as a retinoic acid receptor ligand. The current study investigated the effects of A2E on retinal pigment epithelial (RPE) cells in vivo and was performed to extend the understanding of the effects of A2E. Firstly, subretinal injection of A2E was performed and 3 weeks after the injection, and it was demonstrated that subretinal injection of A2E induced RPE cell death, and concomitant upregulation of vascular endothelial growth factor (VEGF) in the RPE and choroid. The upregulation of VEGF was attenuated by an RARα antagonist. Next we performed laser photocoagulation in mice that accumulated A2E either after subretinal injection, by Ccl2 gene knockout or by aging demonstrated that mice that accumulated A2E in the RPE, which showed higher rates of choroidal neobascularization (CNV) formation after weak laser injury than the controls and the formation of CNV was inhibited by an RARα antagonist in all models tested. The data suggest that A2E accumulation induces RPE cell death, and concomitant increase of VEGF. Accumulation of A2E alone is not sufficient to induce CNV in vivo, but induces the expression of VEGF in RPE and choroid. The mice that accumulated A2E in RPE cells are vulnerable to CNV development via RAR activation, at least in part. J. Cell. Physiol. 220: 469–475, 2009. © 2009 Wiley‐Liss, Inc.
TRAIL‐induced apoptosis of FHIT‐negative lung cancer cells is inhibited by FHIT re‐expression
Authors: Mirandola Prisco , Gobbi Giuliana , Sponzilli Ivonne , Malinverno Chiara , Cavazzoni Andrea , Alfieri Roberta , Petronini Pier Giorgio , Vitale Marco
Published: May 2009

Fragile histidine triad (FHIT) is a tumor suppressor gene whose allelic loss is associated to a number of human cancers. FHIT protein acts as a diadenosine oligophosphate hydrolase, but its tumor suppressive activity appears as independent from its enzymatic activity. Tumor necrosis factor (TNF)‐related apoptosis inducing ligand (TRAIL) can induce apoptosis in the FHIT‐negative non‐small lung cancer cell line Calu‐1. We generated four FHIT‐inducible Calu‐1 cell clones and demonstrated that FHIT expression was able to protect cells from TRAIL‐induced apoptosis, without affecting TRAIL‐receptors surface expression. FHIT‐specific small interference RNA transfection of SV40‐immortalized normal bronchial BEAS cells that show levels of FHIT protein comparable to those of normal bronchial cells, resulted in a significant increase of TRAIL‐induced apoptosis. Of note, suramin‐mediated inhibition of FHIT enzymatic activity also enhanced TRAIL‐induced apoptosis. We conclude that FHIT expression in lung cancer cells is protective from TRAIL‐induced apoptosis. Our data suggest that FHIT exerts this protective effect downstream TRAIL‐receptors and likely requires its dinucleoside‐triphosphate hydrolase activity. As TRAIL represents in the near future a good candidate for death ligands‐based anticancer therapy, its potential therapeutic use should be envisaged as preliminary to molecular genetics interventions or drug‐induced epigenetic modulations aimed to restoring FHIT gene expression levels in non‐small cells lung tumors. J. Cell. Physiol. 220: 492–498, 2009. © 2009 Wiley‐Liss, Inc.
Synthesis and biological evaluation of novel conjugated coumarin‐thiazole systems
Authors: Chimenti Franco , Carradori Simone , Secci Daniela , Bolasco Adriana , Chimenti Paola , Granese Arianna , Bizzarri Bruna
Published: May 2009

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Seven new 2,4‐disubstituted thiazoles have been synthesized by Hantzsch condensation and assayed for several biological activities for a preliminary screening. They have been fully characterized by elemental analysis, UV–Vis spectroscopy, TG‐DTA, IR, and 1H NMR as well. These structures display different pharmacological (antimicrobic activity, citotoxicity, and hMAO inhibition) and industrial properties (complete transparency in the region between 465–800 nm and high thermal stability) varying on their substituents and could be considered as good lead compounds for further developments. J. Heterocyclic Chem., (2009).
A simple preparation of ethyl 2,5‐dimethylfuran‐3‐carboxylate and 2,5‐dimethylfuran‐3,4‐dicarboxylic acid from diethyl 2,3‐diacetylsuccinate
Authors: Wang Gang‐Qiang , Guan Zhi , Tang Rong‐Chang , Ostojic Zeljko , Jones T. Nicholas , Wu Ting‐Ting , He Yan‐Hong
Published: May 2009

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A simple preparation of ethyl 2,5‐dimethylfuran‐3‐carboxylate (3), 2,5‐dimethylfuran‐3,4‐dicarboxylic acid (4), and diethyl 2,5‐dimethylfuran‐3,4‐dicarboxylate (5) by treatment of diethyl 2,3‐diacetylsuccinate (2) with aqueous HCl is reported. The reaction is performed under organic solvent free conditions from a readily available cheap starting material. J. Heterocyclic Chem., (2009).
MRI diffusion tensor tracking of a new amygdalo‐fusiform and hippocampo‐fusiform pathway system in humans
Authors: Smith Charles D. , Lori Nicolas F. , Akbudak Erbil , Sorar Ertugrul , Gultepe Eren , Shimony Joshua S. , McKinstry Robert C. , Conturo Thomas E.
Published: May 2009

Purpose

To use MRI diffusion‐tensor tracking (DTT) to test for the presence of unknown neuronal fiber pathways interconnecting the mid‐fusiform cortex and anteromedial temporal lobe in humans. Such pathways are hypothesized to exist because these regions coactivate in functional MRI (fMRI) studies of emotion‐valued faces and words, suggesting a functional link that could be mediated by neuronal connections.

Materials and Methods

A total of 15 normal human subjects were studied using unbiased DTT approaches designed for probing unknown pathways, including whole‐brain seeding and large pathway‐selection volumes. Several quality‐control steps verified the results.

Results

Parallel amygdalo‐fusiform and hippocampo‐fusiform pathways were found in all subjects. The pathways begin/end at the mid‐fusiform gyrus above the lateral occipitotemporal sulcus bilaterally. The superior pathway ends/begins at the superolateral amygdala. The inferior pathway crosses medially and ends/begins at the hippocampal head. The pathways are left‐lateralized, with consistently larger cross‐sectional area, higher anisotropy, and lower minimum eigenvalue (D‐min) on the left, where D‐min assesses intrinsic cross‐fiber diffusivity independent of curvature.

Conclusion

A previously‐undescribed pathway system interconnecting the mid‐fusiform region with the amygdala/hippocampus has been revealed. This pathway system may be important for recognition, memory consolidation, and emotional modulation of face, object, and lexical information, which may be disrupted in conditions such as Alzheimer's disease. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Synoptic‐based evaluation of climatic response to vegetation change over southern Africa
Authors: MacKellar Neil , Tadross Mark , Hewitson Bruce
Published: May 2009

The results of regional climate model (RCM) simulations of the effects of vegetation change in southern Africa are analysed to asses the role of synoptic forcing in land–atmosphere interactions. A self‐organizing map (SOM) is used to identify the dominant large‐scale features in the atmospheric boundary conditions used to force the RCM. The fields used to characterize the large‐scale circulation are geopotential height at 850 and 500 hPa and total precipitable water between these two levels. For each of the patterns (nodes) identified in these variables by the SOM, the mean RCM‐simulated response to vegetation change is evaluated. Notable differences are seen in the response of precipitation, near‐surface temperature and geopotential heights to the land surface change between different nodes. Conditions characterized by strong sub‐tropical anticyclones and low atmospheric moisture show the greatest temperature and geopotential height changes and are most sensitive to changes in radiative fluxes, whereas precipitation and surface hydrological processes are more sensitive under conditions of weak subsidence and high levels of atmospheric moisture. Copyright © 2009 Royal Meteorological Society
Observational relationship of sea surface temperatures and precedent soil moisture with summer precipitation in the U.S. Great Plains
Authors: Meng Lei , Quiring Steven M.
Published: May 2009

In this study, the relationship between precedent soil moisture anomalies and summer precipitation in the U.S. Great Plains was examined using Variable Infiltration Capacity (VIC)‐simulated soil moisture and the Standardized Precipitation Index (SPI). The influence of Niño sea surface temperatures (SSTs) on summer precipitation was also investigated to compare their relative contributions to those from local moisture recycling.

Results indicate that spring (May 1st) soil moisture is significantly correlated with summer SPI only during periods when Niño SSTs are not strongly correlated with summer SPI (e.g. 1920s–1930s). During periods when Niño SSTs are strongly correlated with summer SPI (e.g. 1940s–1980s), spring soil moisture is not a good predictor of summer precipitation in the U.S. Great Plains. The periods of strong correlation between Niño SSTs and summer precipitation are associated with strong SST persistence. Results also indicate that the impact of soil moisture anomalies and SST on summer precipitation varies greatly in space and time. Positive soil moisture–precipitation correlations are generally associated with high soil moisture persistence and negative soil moisture–precipitation correlations are linked to low soil moisture persistence. In addition, high SST persistence tends to favour (inhibit) negative (positive) soil moisture–precipitation correlations. This study suggests that both local soil moisture and remote SST anomalies influence summer precipitation in the U.S. Great Plains. The soil moisture anomalies are of greatest importance during years when Niño SST persistence is low. Copyright © 2009 Royal Meteorological Society
Effect of plant phenolics, tocopherol and ascorbic acid on oxidative stability of pork patties
Authors: Haak Lindsey , Raes Katleen , De Smet Stefaan
Published: May 2009

BACKGROUND: There is great interest in the use of naturally occurring antioxidants to delay oxidation in meat products. The effect of rosemary extract (RE), green tea extract (TE), tocopherol, trolox, ascorbic acid (AA) and ascorbyl palmitate (AP), at levels of 50–200 ppm of antioxidant components, on colour (CIE L*a*b*), lipid (TBARS) and protein oxidation (thiol groups) in fresh, frozen and cooked pork patties during illuminated chill storage was investigated. Individual components of RE and TE were also tested.

RESULTS: RE, TE, AP, tocopherol and trolox equally inhibited lipid oxidation in fresh and frozen patties, whereas for cooked patties RE was most effective. AA stimulated lipid oxidation. No dose effect in the range of 50–200 ppm was found for fresh and frozen patties, whereas for cooked patties higher doses of RE and TE more efficiently prevented lipid oxidation. Protein oxidation was hardly influenced by antioxidant treatment. Colour stability decreased as follows: tocopherol, AA and AP > RE and TE > trolox. Antioxidant properties of the extracts and their major antioxidant components were comparable.

CONCLUSION: The relative effect of the antioxidants depends on the oxidation parameter assessed, the applied dose and the hydrophilic/lipophilic character. Copyright © 2009 Society of Chemical Industry
Review of flavonoids and other phenolics from fruits of different tomato (Lycopersicon esculentum Mill.) cultivars
Authors: Slimestad Rune , Verheul Michel
Published: May 2009

BACKGROUND: Tomato, one of the most important vegetables worldwide, contains a range of flavonoids and phenolic acids in addition to lycopene, which are regarded as potentially useful compounds with respect to health benefits. Composition data in fresh tomatoes vary due to genetic and environmental factors and cultural practices. Breeding programs aim to produce tomatoes with enhanced levels of flavonoids and other phenolics.

RESULTS: The present paper gives an overview of flavonoids, stilbenoids and other phenolics reported to occur in tomato fruits. Contents are reported for a wide range of cultivars and types. Metabolism of phenolics during fruit maturation and tissue location are described, and an overview of measured contents is given. Effects of environmental conditions and cultural practices are estimated using available literature. Recent literature on transgenic tomatoes is included, and possibilities for regulating phenolic contents in tomatoes are discussed.

CONCLUSION: The literature review clearly discloses a rapidly growing interest in flavonoids and other phenolics in tomato fruits and products made thereof. This is particularly connected to the antioxidant properties of these compounds as well as other possible health effects. Choice of cultivar and effects of environment and agronomic practices are important factors with respect to phenolic qualities and quantities of tomatoes. Copyright © 2009 Society of Chemical Industry
Effects of modified atmosphere packaging with different sizes of silicon gum film windows on Salicornia bigelovii Torr. storage
Authors: Lu Dong‐He , Zhang Min , Wang Shao‐Jin , Cai Jin‐Long , Zhu Cheng‐Pei , Zhou Xiang
Published: May 2009

BACKGROUND: Salicornia bigelovii Torr. is a promising seasonal plant using seawater production but perishable with short shelf‐life under ambient conditions. To develop a modified atmosphere packaging (MAP) for extension of S. bigelovii shelf‐life, a nonselective polyethylene/polyamide (PE/PA) bag combining different sizes (0.6, 1.0 and 1.4 cm2) of silicon gum film (SGF) windows was tested, and low‐density polyethylene (LDPE) and perforated (1.0 cm2) PE/PA bags were used as controls.

RESULTS: During 36 days of storage at 2 °C, the equilibrium compositions of O2/CO2 in LDPE, SGF1 (0.6 cm2), SGF2 (1.0 cm2) and SGF3 (1.4 cm2) were 3.0–5.0/4.5–6.5 kPa, 0.5–1.5/8.5–19.0 kPa, 2.5–5.0/5.5–10.0 kPa, and 6.0–13.0/4.0–6.5 kPa, respectively. Passive MAP treatments improved the quality attributes of S. bigelovii during initial storage; however, the 0.6 cm2 SGF package markedly accelerated deterioration over the latter storage. The 1.0 cm2 SGF package was observed to provide the optimal condition for S. bigelovii storage.

CONCLUSION: The results show that passive MAP with optimized sizes of SGF windows could be an effective technique for prolonging shelf‐life of S. bigelovii. Copyright © 2009 Society of Chemical Industry
The prognostic impact of the number of lymph nodes retrieved after neoadjuvant chemoradiotherapy with mesorectal excision for rectal cancer
Authors: Kim Young‐Wan , Kim Nam‐Kyu , Min Byung‐Soh , Lee Kang‐Young , Sohn Seung‐Kook , Cho Chang‐Hwan , Kim Hoguen , Keum Ki‐Chang , Ahn Jung‐Bai
Published: May 2009

Background

We aimed to assess factors associated with the number of nodes retrieved and the impact of the number of lymph nodes in rectal cancer patients who underwent neoadjuvant chemoradiation with radical surgery.

Methods

A total of 258 patients were enrolled. Lymph nodes were retrieved from specimens using a manual dissection technique.

Results

Of the 258 patients, nine patients had an absence of lymph nodes (ypNx), 150 patients had a node‐negative status (ypN(−)) and 99 patients had node‐positive disease (ypN(+)). An advanced ypT classification (ypT3,4) and larger tumor (>4 cm) were associated with an increased number of nodes retrieved. The pretreatment CEA level (>5 ng/ml) and ypN(+) classification were significant risk factors for cancer specific and recurrence free survival. There was no significant difference of oncological outcomes among ypNx patients and a subset of ypN(−) patients based on the number of nodes retrieved using three cutoff values (1–11, 12–25, and 25–65 nodes).

Conclusions

In a neoadjuvant setting, ypN(+) disease was an independent risk factor for oncological outcomes. An absence of nodes does not represent an inferior oncological outcome. The number of nodes does not seen to impact survival and recurrence in ypN(−) patients. J. Surg. Oncol. 2009;100:1–7. © 2009 Wiley‐Liss, Inc.