bluuebunny/crossref_metadata_2025 huggingface dataset:
A new direction for anticoagulants: Inhibiting fibrin assembly with PEGylated fibrin knob mimics
Authors: Stabenfeldt Sarah E. , Aboujamous Nader M. , Soon Allyson S.C. , Barker Thomas H.
Published: April 2011

Current anticoagulants target coagulation factors upstream from fibrin assembly and polymerization (i.e., formation of fibrin clot). While effective, this approach requires constant patient monitoring since pharmacokinetics and pharmacodynamics vary from patient to patient. To address these limitations, we developed an alternative anticoagulant that effectively inhibits fibrin polymerization. Specifically, we investigated PEGylated fibrin knob “A” peptides, evaluating the effect of both polyethylene glycol (PEG) chain length (0, 2, 5, and 10–30 kDa) and knob peptide sequence (GPRPAAC, GPRPFPAC, and GPRPPERC) on inhibiting fibrin polymerization (i.e., clot formation). Thrombin‐initiated clotting assays with purified fibrinogen were performed to compare clot formation with each peptide–PEG conjugate. Results indicated a biphasic effect of PEG chain length, whereby, active‐PEG conjugates demonstrated increasingly enhanced inhibition of fibrin polymerization from 0 to 5 kDa PEG. However, the anticoagulant activity diminished to control levels for PEG chains above 5 kDa. Ultimately, we observed a 10‐fold enhancement of anticoagulant activity with active peptides PEGylated with 5 kDa PEG compared to non‐PEGylated knob peptides. The sequence of the active peptide significantly influenced the anticoagulant properties only at the highest 1:100 molar ratio where GPRPFPAC‐5 kDa PEG and GPRPPERC‐5 kDa PEG demonstrated significantly lower percent clottable protein than GPRPAAC‐5 kDa PEG. Moreover, human plasma treated with the active 5 kDa PEG conjugate exhibited delayed prothrombin time to within the therapeutic range specified for oral anticoagulants. Collectively, this study demonstrated the utility of PEGylated fibrin knob peptides as potential anticoagulant therapeutics. Biotechnol. Bioeng. 2011;108: 2424–2433. © 2011 Wiley Periodicals, Inc.
Influence of steam pretreatment severity on post‐treatments used to enhance the enzymatic hydrolysis of pretreated softwoods at low enzyme loadings
Authors: Kumar Linoj , Chandra Richard , Saddler Jack
Published: April 2011

It is recognized that some form of post‐treatment will usually be required if reasonable hydrolysis yields (>60%) of steam pretreated softwood are to be achieved when using low enzyme loadings (5 FPU/g cellulose). In the work reported here we modified/removed lignin from steam pretreated softwood while investigating the influence that the severity of pretreatment might have on the effectiveness of subsequent post‐treatments. Although treatment at a lower severity could provide better overall hemicellulose recovery, post‐treatment was not as effective on the cellulosic component. Pretreatment at medium severity resulted in the best compromise, providing reasonable recovery of the water soluble hemicellulose sugars and the use of post‐treatment conditions that significantly increased the enzymatic hydrolysis of the water insoluble cellulosic component. Post‐treatment with alkaline hydrogen peroxide or neutral sulfonation resulted in 62% cellulose hydrolysis at an enzyme loading of 5 FPU/g cellulose, which was four times greater than was obtained when the cellulosic fraction was not post‐treated. When the enzyme loading was increased to 15 FPU/g cellulose, the post‐treated cellulosic fraction was almost completely hydrolyzed to glucose. Despite the higher lignin content (44%) of the sulfonated substrate, similar hydrolysis yields to those achieved after alkaline peroxide post‐treatment (14% lignin content) indicated that, in addition to lignin removal, lignin modification also plays an important role in influencing the effectiveness of hydrolysis when low enzyme loadings are used. Biotechnol. Bioeng. 2011;108: 2300–2311. © 2011 Wiley Periodicals, Inc.
Engineered Bacterial Mimics of Human Drug Metabolizing Enzyme CYP2C9
Authors: Rentmeister Andrea , Brown Tristan R. , Snow Christopher D. , Carbone Martina N. , Arnold Frances H.
Published: April 2011

Simple and universal methods for the preparation of human drug metabolites are required to produce quantities sufficient for their characterization and toxicity testing. Synthetic chemistry lacks general catalysts for selective oxidation of unactivated CH bonds, a transformation that plays a key role in metabolism; bioconversions using P450 enzymes have emerged as a powerful alternative. Variants of P450BM3 from Bacillus megaterium act on diverse substrates, including drugs. Acidic substrates, such as the compounds metabolized by CYP2C9, which is one of three main hepatic human P450s, are not accepted by P450BM3 variants engineered to date. Herein, we report bacterial mimics of CYP2C9, which are active on two widely administered drugs, naproxen and ibuprofen, that are CYP2C9 substrates in vivo. These P450BM3 variants can also act on desmethylnaproxen, the human metabolite of naproxen, and convert it to the 1,4‐naphthoquinone derivative. We analyzed the crystal structure of the heme domain of an early intermediate in the directed‐evolution experiment. The active site mutation, L75R, which initially conferred activity on charged substrates, dramatically increased structural flexibility in the B′‐helix. This increased flexibility, which was accompanied by a dramatic decrease in enzyme stability, may contribute to the variant’s ability to accept a broader range of substrates.
Mechanism and Site Requirements of Thiophene Hydrodesulfurization Catalyzed by Supported Pt Clusters
Authors: Wang Huamin , Iglesia Enrique
Published: April 2011

Kinetic, isotopic, and chemical analysis methods are used to examine the identity and kinetic relevance of elementary steps and the effects of Pt cluster size on thiophene hydrodesulfurization (HDS) turnover rates. Quasi‐equilibrated H2 and H2S heterolytic dissociation steps lead to sulfur chemical potentials given by the prevalent H2S/H2 ratio and to cluster surfaces with a metallic bulk, but near‐saturation sulfur coverages, during steady‐state catalysis. Sulfur‐vacancies on such surfaces are required for η1(S) or η4 thiophene adsorption modes and for H2 and H2S dissociation steps. H‐assisted CS bond cleavage of η1(S) thiophene and H‐addition to η4 thiophene limits rates of direct desulfurization and hydrogenation sulfur removal pathways, respectively. These steps, their kinetic relevance, and the prevalent sulfur‐saturated surfaces resemble those on Ru clusters; they are also consistent with the observed kinetic effects of reactants and products on rates, with the rapid isotopic exchange in H2/D2/H2S mixtures during HDS catalysis, and with measured H2/D2 kinetic isotope effects. Small Pt clusters exhibit lower turnover rates, stronger inhibition by H2S, and a greater preference for desulfurization pathways than those of large clusters. These effects reflect the prevalence of coordinatively unsaturated corner and edge sites on small clusters, which bind sulfur atoms more strongly and lead to lower densities of vacancies and to a preference for η1(S)‐bound thiophene species. Sulfur binding energies and their concomitant effects on the number of available vacancies also account for the higher turnover rates measured on Pt clusters compared with Ru clusters of similar size. These data and their mechanistic interpretation suggest that the concepts and steps proposed here apply generally to hydrogenation and direct desulfurization of organosulfur compounds. Taken together with similar observed effects of oxygen binding strength, metal identity, and cluster size for oxidation reactions of NO, hydrocarbons, and oxygenates, which also require vacancies in their respective kinetically relevant steps, these data also indicate that low reactivity of small clusters may reflect in most instances their coordinative unsaturation and the concomitant kinetic and thermodynamic preference for low vacancy concentrations on nearly saturated surfaces.
Neutral Tellurium Rings in the Coordination Polymers [Ru(Te9)](InCl4)2, [Ru(Te8)]Cl2, and [Rh(Te6)]Cl3
Authors: Günther Anja , Isaeva Anna , Baranov Alexey I. , Ruck Michael
Published: April 2011

Shiny black, air‐insensitive crystals of tellurium‐rich one‐dimensional coordination polymers were synthesized by melting a mixture of the elements with TeCl4. The compounds [Ru(Te9)](InCl4)2and [Ru(Te8)]Cl2crystallize in the monoclinic space group typeC2/c, whereas [Rh(Te6)]Cl3adopts the trigonal space group typeRc. In the crystal structures, linear, positively charged [Mm+(Ten±0)] (M=Ru,m=2; Rh,m=3) chains run parallel to thecaxes. Each of the uncharged Tenmolecules (n=6, 8, 9) coordinates two transition‐metal atoms as a bridging bis‐tridentate ligand. Because the coordinating tellurium atoms act as electron‐pair donors, the 18‐electron rule is fulfilled for the octahedrally coordinated transition‐metal cations. Based on DFT calculations, the quantum theory of atoms in molecules (QTAIM) and the electron localizability indicator (ELI) provide insight into the principles of the polar donor bonding in these complexes. Comparison with optimized ring geometries reveals substantial tension in the coordinating tellurium molecules.
ChemInform Abstract: Low‐Symmetry Uranyl Pyrophosphate Cage Clusters.
Authors: Ling Jie , Qiu Jie , Szymanowski Jennifer E. S. , Burns Peter C.
Published: April 2011

Na64Li26 [(UO2)45(O2)44 (P2O7)23]·3H2O is obtained by self‐assembly from a solution containing UO2(NO3)2, LiOH, H2O2, Na2P2O7, and (COOH)2 (air, 24 h).
ChemInform Abstract: Practical Access to Highly Enantioenriched Quaternary Carbon Michael Adducts Using Simple Organocatalysts.
Authors: Nugent Thomas C. , Shoaib Mohammad , Shoaib Amna
Published: April 2011

Michael addition of α‐branched aldehydes towards nitroolefins is efficiently catalyzed by an organocatalyst consisting of O‐tert‐butylthreonine as amino acid, sulfamide as hydrogen bond donor and DMAP as base.
ChemInform Abstract: Hydrogen Bond Induced Enantioselectivity in Mn(salen)‐Catalyzed Sulfoxidation Reactions.
Authors: Voss Felix , Herdtweck Eberhardt , Bach Thorsten
Published: April 2011

A novel MnCl(salen)‐derived complex is synthesized and applied as chiral catalyst in enantioselective sulfoxidation reactions.
ChemInform Abstract: In situ Generation of Palladium Nanoparticles: Reusable, Ligand‐Free Heck Reaction in PEG‐400 Assisted by Focused Microwave Irradiation.
Authors: Du Zhengyin , Zhou Wanwei , Bai Lin , Wang Fen , Wang Jin‐Xian
Published: April 2011

Polyethylene glycol 400 is found to reduce Pd(II) to Pd(0) and acts as stabilizer for the Pd‐nanoparticles.
ChemInform Abstract: A General and Selective Iron‐Catalyzed Aminocarbonylation of Alkynes: Synthesis of Acryl‐ and Cinnamides.
Authors: Driller Katrin Marie , Prateeptongkum Saisuree , Jackstell Ralf , Beller Matthias
Published: April 2011

Under an optimized CO pressure and use of a diazabutadiene as ligand, the chemoselective monocarbonylation of a variety of aromatic or aliphatic terminal alkynes in the presence of primary or secondary amines is achieved, to give in all cases (E)‐configurated α,β‐unsaturated amides.
ChemInform Abstract: Oxidoreductive Coupling of Thiols with Aryl Halides Catalyzed by Copper on Iron.
Authors: Kovacs Szabolcs , Novak Zoltan
Published: April 2011

The thiolation of aromatic halides proceeds by fast oxidation of the thiol in the initial step, followed by reductive cleavage of the disulfide intermediate.
ChemInform Abstract: Catalytic Asymmetric Synthesis of γ‐Substituted Vinyl Sulfones.
Authors: Lopez Rosa , Zalacain Maitane , Palomo Claudio
Published: April 2011

The conjugate addition of β‐nitroethylsulfones as bench‐storable readily available new formal β‐sulfonyl vinyl anions offers the advantages of a simple one‐pot procedure without the need for intermediate isolation, the use of an organocatalyst in substoichiometric quantities, very high chemical efficiency and great substrate tolerance.
ChemInform Abstract: Pd/PR3‐Catalyzed Cross‐Coupling of Aromatic Carboxylic Acids with Electron‐Deficient Polyfluoroarenes via Combination of Decarboxylation with sp2 C—H Cleavage.
Authors: Zhao Huaiqing , Wei Ye , Xu Jing , Kan Jian , Su Weiping , Hong Maochun
Published: April 2011

Unfortunately, aromatic carboxylic acids without ortho‐ substituents do not yield the desired coupling products.
ChemInform Abstract: Solid‐Supported Palladium Nano and Microparticles: An Efficient Heterogeneous Catalyst for Ligand‐Free Suzuki—Miyaura Cross Coupling Reaction.
Authors: Das Pralay , Sharma Dharminder , Shil Arun K. , Kumari Avnesh
Published: April 2011

The catalyst can be reused up to 7 runs without significant loss of activity and it is stable enough under moist conditions.
ChemInform Abstract: Vinyldisiloxanes: Their Synthesis, Cross‐Coupling and Applications.
Authors: Sore Hannah F. , Boehner Christine M. , Laraia Luca , Logoteta Patrizia , Prestinari Cora , Scott Matthew , Williams Katharine , Galloway Warren R. J. D. , Spring David R.
Published: April 2011

Aliphatic and aromatic vinyldisiloxanes are applied in the fluoride‐free cross‐coupling reactions with aryl iodides to afford the (E)‐products mostly exclusively.
ChemInform Abstract: Synthesis of Symmetrical Diarylalkyne from Palladium‐Catalyzed Decarboxylative Couplings of Propiolic Acid and Aryl Bromides under Water.
Authors: Park Kyungho , Bae Goun , Park Ahbyeol , Kim Yong , Choe Jaehoon , Song Kwang Ho , Lee Sunwoo
Published: April 2011

The reaction proceeds in the presence of a phase transfer surfactant and is efficiently catalyzed by two different systems.
ChemInform Abstract: Fe3O4 Nanoparticle‐Supported Copper(I) Pybox Catalyst: Magnetically Recoverable Catalyst for Enantioselective Direct‐Addition of Terminal Alkynes to Imines.
Authors: Zeng Tieqiang , Yang Luo , Hudson Reuben , Song Gonghua , Moores Audrey R. , Li Chao‐Jun
Published: April 2011

The catalyst exhibits excellent reactivity to afford the propargyl amines with high yields and enantioselectivities.
ChemInform Abstract: Organocatalytic Enantioselective Friedel—Crafts Reactions of 1‐Naphthols with Aldimines.
Authors: Liu Guixia , Zhang Shilei , Li Hao , Zhang Tangzhi , Wang Wei
Published: April 2011

The reaction is catalyzed best by the alkaloid‐derived bifunctional catalyst.
ChemInform Abstract: Ytterbium Triflate Catalyzed Synthesis of β‐Functionalized Indole Derivatives.
Authors: Epifano Francesco , Genovese Salvatore , Rosati Ornelio , Tagliapietra Silvia , Pelucchini Caroline , Curini Massimo
Published: April 2011

Ultrasound‐assisted condensation of indole, aldehydes, and dimethyl malonate represents the first example of the Yonemitsu three‐component reaction catalyzed by a Lewis acid without the need of other promoters such as amines.
ChemInform Abstract: Synthesis of 1,2,4‐Trisubstituted‐1,2,5,6‐tetrahydropyridines.
Authors: Chang Meng‐Yang , Lee Ming‐Fang , Lee Nien‐Chia , Huang Yu‐Ping , Lin Chung‐Han
Published: April 2011

A synthesis of title compounds (V) is achieved via NBS‐mediated alkoxybromination, DBU‐promoted formation of an enamine and reaction with Tms‐substituted C‐nucleophiles.
ChemInform Abstract: Per(poly)fluoroalkanesulfinamides Assisted Diastereoselective Three‐Component Inverse‐Electron‐Demand Aza Diels—Alder Reaction.
Authors: Li Peng , Liu Li‐Juan , Liu Jin‐Tao
Published: April 2011

Three‐component inverse‐electron‐demand aza‐Diels—Alder reaction of polyfluoroalkanesulfinamide (III) with enones (I) and enol ether (II) provides access to a range of tetrahydropyridine derivatives with high endo‐ and facial selectivities (up to < 100:1).
ChemInform Abstract: Condensed Isoquinolines. Part 36. Cyclization of N‐Alkyl‐3‐(2‐benzoylbenzyl)azolium Salts. A Novel Method of Preparing Azolo[b]isoquinolines.
Authors: Potikha L. M. , Sypchenko V. V. , Kovtunenko V. A.
Published: April 2011

The preparation of azoloisoquinolinium bromides (IV) and (VIII) is based on the alkylation of N‐alkyl‐1,3‐diazoles, e.g. (II), or 1,3‐thiazole derivative (VI) using benzophenone derivatives (I) as novel equivalents of 1,4‐dielectrophile synthons, followed by cyclization of the quaternary azolium salts (III) and (VII) in the presence of a base.
ChemInform Abstract: One‐Pot Construction of Aza‐ or Oxa‐Bridged Benzocycloheptanes from Readily Available 2,3‐Allenyl Malonates or 2,3‐Allenols and o‐Iodobenzaldehyde or Imine.
Authors: Li Qiankun , Jiang Xinpeng , Fu Chunling , Ma Shengming
Published: April 2011

A variety of biologically relevant racemic aza‐bridged and racemic and optically pure oxa‐bridged benzocycloheptane derivatives is prepared.
ChemInform Abstract: 3‐[Benzimidazo‐ and 3‐Benzothiadiazoleimidazo‐(1,2‐c)quinazolin‐5‐yl]‐2H‐chromene‐2‐ones as Potent Antimicrobial Agents.
Authors: Kuarm B. Suresh , Reddy Y. Thirupathi , Madhav J. Venu , Crooks Peter A. , Rajitha B.
Published: April 2011

The antimicrobial activities of the title compounds (III) and (V) are evaluated.
ChemInform Abstract: Synthesis of 4‐(Trifluoromethyl)pyrido[4,3‐d]pyrimidine Derivatives.
Authors: Vasil'ev L. S. , Baranin S. V. , Ignatenko A. V. , Nelyubina Yu. V. , Dorokhov V. A.
Published: April 2011

The title compounds, whose known derivatives possess a wide range of biological activity, are synthesized for the first time.
ChemInform Abstract: Construction of Mononitrogen Heterocycles with a Combined System of 1‐Azaspiro[4.n]alkene and 3‐Benzazocine Fragments Through the Intramolecular Eight‐Membered Heck Cyclization.
Authors: Kuznetsov N. Yu. , Khrustalev V. N. , Bubnov Yu. N.
Published: April 2011

A new type of cyclization reaction in the presence of the Herrmann—Beller palladacycle is presented.
ChemInform Abstract: Reactions of α‐Perfluorophenylpyrylium Perchlorates with Hydrazine Hydrate.
Authors: Kargapolova I. Yu. , Shmuilovich K. S. , Beregovaya I. V. , Orlova N. A.
Published: April 2011

The title reaction affords new polyfluorinated compounds.
ChemInform Abstract: Synthesis and Photochromic Properties of Novel Nonsymmetric Dihetarylethenes Based on Benzindole and Thiophene.
Authors: Metelitsa A. V. , Rybalkin V. P. , Makarova N. I. , Levchenko P. V. , Kozyrev V. S. , Shepelenko E. N. , Popova L. L. , Bren' V. A. , Minkin V. I.
Published: April 2011

Unlike the title of furandione (I), benzindole derivatives (II) exhibit photochromic and fluorescence properties in solutions.
ChemInform Abstract: Rhodium‐Catalyzed Asymmetric Addition of Arylboronic Acids to γ‐Phthalimido‐substituted‐α,β‐unsaturated Carboxylic Acid Esters: An Approach to γ‐Amino Acids.
Authors: Han Fuzhong , Chen Jun , Zhang Xiangyang , Liu Jibing , Cun Linfeng , Zhu Jin , Deng Jingen , Liao Jian
Published: April 2011

The mild process affords the desired products generally with excellent enantioselectivity.
ChemInform Abstract: Wilsoniamines A (I) and B (II): Novel Alkaloids from the Temperate Australian Bryozoan, Amathia wilsoni
Authors: Carroll Anthony R. , Duffy Sandra , Sykes Melissa , Avery Vicky M.
Published: April 2011

isolation together with amathamide H (III)
ChemInform Abstract: Hyrtioseragamines A and B, New Alkaloids from the Sponge Hyrtios Species.
Authors: Takahashi Yohei , Iinuma Yoshiro , Kubota Takaaki , Tsuda Masashi , Sekiguchi Mitsuhiro , Mikami Yuzuru , Fromont Jane , Kobayashi Jun'ichi
Published: April 2011

The title compounds are the first natural products possessing a furopyrazine moiety.
ChemInform Abstract: Two New Paeciloxocins from a Mangrove Endophytic Fungus Paecilomyces sp.
Authors: Wen Lu , Chen Gang , She Zhigang , Yan Chunyan , Cai Juanni , Mu Lei
Published: April 2011

Isolation and structure elucidation of two new compounds, paeciloxocins A (Ia) and B (Ib), are described.
ChemInform Abstract: Controlled Synthesis and Properties of Rare Earth Nanomaterials
Authors: Yan Chun‐Hua , Yan Zheng‐Guang , Du Ya‐Ping , Shen Jie , Zhang Chao , Feng Wei
Published: April 2011

Review: 828 refs.
ChemInform Abstract: Ammonia and Dinitrogen Activation by Surface Organometallic Chemistry on Silica‐Grafted Tantalum Hydrides
Authors: Chow Catherine , Taoufik Mostafa , Quadrelli Elsje Alessandra
Published: April 2011

Review: 83 refs.
ChemInform Abstract: Supramolecular Chemistry of Silver
Authors: Sun Wei‐Yin , Bai Zheng‐Shuai , Yu Jin‐Quan
Published: April 2011

Review: 80 refs.
ChemInform Abstract: Activation of “Inert” Alkenyl/Aryl C—O Bond and Its Application in Cross‐Coupling Reactions
Authors: Li Bi‐Jie , Yu Da‐Gang , Sun Chang‐Liang , Shi Zhang‐Jie
Published: April 2011

Review: 261 refs.
ChemInform Abstract: Entrapping Homogeneous Catalysts by Sol—Gel Methods: The Bottom‐up Synthesis of Catalysts That Recycle and Cascade
Authors: Marr A. C. , Marr P. C.
Published: April 2011

Review: 51 refs.
ChemInform Abstract: Palladium‐ and Copper‐Mediated N‐Aryl Bond Formation Reactions for the Synthesis of Biological Active Compounds
Authors: Fischer Carolin , Koenig Burkhard
Published: April 2011

Review: 80 refs.
ChemInform Abstract: Unsymmetric Pincer‐Type Palladacycles: A New Family of Catalysts for Cross‐Coupling Reactions
Authors: Moreno Isabel , SanMartin Raul , Herrero M. Teresa , Dominguez Esther
Published: April 2011

Review: 55 refs.
ChemInform Abstract: Azides in Carbohydrate Chemistry
Authors: Beckmann Henning S. G. , Wittmann Valentin
Published: April 2011

Review: 186 refs.
ChemInform Abstract: Ionic Liquid Mediated Formation of 5‐Hydroxymethylfurfural — A Promising Biomass‐Derived Building Block
Authors: Zakrzewska Malgorzata E. , Bogel‐Lukasik Ewa , Bogel‐Lukasik Rafal
Published: April 2011

Review: 120 refs.
ChemInform Abstract: New Reactions of Copper Acetylides: Catalytic Dipolar Cycloadditions and Beyond
Authors: Fokin Valery V.
Published: April 2011

Review: 132 refs.
ChemInform Abstract: Controlling the Dynamics of Molecular Encapsulation and Gating
Authors: Rieth Stephen , Hermann Keith , Wang Bao‐Yu , Badjic Jovica D.
Published: April 2011

Review: 105 refs.
ChemInform Abstract: Fundamental Functionality: Recent Developments in Understanding the Structure—Activity Relationships of Lantibiotic Peptides
Authors: Ross Avena C. , Vederas John C.
Published: April 2011

Review: 47 refs.
ChemInform Abstract: Techniques for Efficient Entrapment of Pharmaceuticals in Biodegradable Solid Micro/Nanoparticles
Authors: Ishihara Tsutomu , Mizushima Tohru
Published: April 2011

Review: 91 refs.
ChemInform Abstract: Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction
Authors: Katritzky Alan R. , Kuanar Minati , Slavov Svetoslav , Hall C. Dennis , Karelson Mati , Kahn Iiris , Dobchev Dimitar A.
Published: April 2011

Review: 902 refs.
ChemInform Abstract: Ionic Liquids from Theoretical Investigations
Authors: Kirchner Barbara
Published: April 2011

Review: 162 refs.
ChemInform Abstract: On‐line Monitoring Reactions by Electrospray Ionization Mass Spectrometry
Authors: Santos Leonardo S.
Published: April 2011

Review: 172 refs.
CFD simulation of stirred tanks: Comparison of turbulence models (Part II: Axial flow impellers, multiple impellers and multiphase dispersions)
Authors: Joshi Jyeshtharaj B. , Nere Nandkishor K. , Rane Chinmay V. , Murthy B. N. , Mathpati Channamallikarjun S. , Patwardhan Ashwin W. , Ranade Vivek V.
Published: April 2011

In the first part of the review, published literature regarding the CFD modelling of single‐phase turbulent flow in stirred tank reactors with radial flow impellers was critically analysed. A brief overview of different turbulence models (standardk − εmodel, RNGk − εmodel, the Reynolds stress model and large eddy simulation) as well as impeller baffle interaction models has been presented in the previous part. This part is concerned with the review of literature regarding CFD simulation of axial flow impellers. Comprehensive simulations have been carried out using various turbulence models and the model predictions (of all the mean velocities, turbulent kinetic energy and its dissipation rate) have been compared with the experimental measurements at various locations in the tank. The strengths and weaknesses of various turbulence models for axial flow impellers is presented. The quantitative comparison of exact and modelled turbulence production, transport and dissipation terms has highlighted the reasons behind the partial success of various modifications of standardk − εmodel as well as Reynolds stress model. Literature efforts on multiple impeller systems and multiphase systems have been discussed in a separate section. Based on these results, suggestions have been made for the future work in this area.
Fibre orientation distribution in turbulent fibre suspensions flowing through an axisymmetric contraction
Authors: Lin Jianzhong , Liang Xiaoyu , Zhang Shanliang
Published: April 2011

The Reynolds averaged Navier–Stokes equation was solved numerically with the Reynolds stress model to get the mean fluid velocity and the turbulent kinetic energy in turbulent fibre suspensions flowing through an axisymmetric contraction. The fluctuating fluid velocity was represented as a Fourier series with random coefficients. Then the slender‐body theory was used to predict the fibre orientation distribution and orientation tensor. Some numerical results are compared with the experimental ones in the turbulent fibre suspensions flowing through a contraction with a rectangular cross‐section. The results show that the fibres with high aspect ratio tend to align its principal axis with the flow direction much easier. High contraction ratio makes the fibre alignment with the flow direction much easier. The contraction ratio has a strong effect on the fibre orientation distribution. Only a small part of the fibre is aligned with the flow direction in the inlet region, while most fibres are aligned with the flow direction when they approach to exit. The fibres are aligned with the flow direction rapidly in the inlet region, after that the fibre orientations change little in the most of the downstream region. The fibres with high aspect ratio are aligned with the flow direction faster when they enter the contraction. The randomising effect of the turbulence becomes significant in the downstream region because of the high turbulent intensity.
Hochwasserschutz an denkmalgeschützten Gebäuden — dargestellt am Beispiel der Alten Amtshauptmannschaft in Grimma
Authors: Burkert Toralf , Plagge Rudolf , Bobbe Axel
Published: April 2011

Die historische Altstadt von Grimma wurde beim Jahrhunderthochwasser 2002 nahezu vollständig überflutet. Das Hochwasser verursachte dabei allein in Grimma Schäden in Höhe von ca. 250 Mio. €. Die Stadt war dadurch die am stärksten geschädigte Kommune an der Mulde. Infolge der verheerenden Auswirkungen des Hochwassers von 2002 im gesamten Freistaat Sachsen wurde u. a. im Auftrag der Landestalsperrenverwaltung, Betrieb Elbaue/Mulde/Untere Wei�e Elster das Hochwasserschutzkonzept für die Mulden im Regierungsbezirk Leipzig erstellt. Es sah für Grimma die Errichtung einer ufernahen Hochwasserschutzmauer vor. Aufgrund des herausragenden Denkmalwertes der muldenseitigen Silhouette der Stadt stand die Prüfung ergänzender und flankierender Ma�nahmen oder auch Alternativvarianten zur Hochwasserschutzmauer im Mittelpunkt der Planungen. Die Ertüchtigung der muldenseitigen Au�enwände der Alten Amtshauptmannschaft war das erste Projekt in Grimma zur behutsamen Einbindung eines denkmalgeschützten Gebäudes in die Hochwasserschutzanlage unter Wahrung seiner historischen Fassadenansicht.

Flood prevention on listed buildings — represented by using the example of the historical building of Alte Amtshauptmannschaft Grimma. The historical old town of Grimma was nearly totally flooded during the one‐hundred‐year flood in 2002. Losses arising from the flood amount to circa 250 millions of Euros only in Grimma. Thereby the town was the most damaged community on the river Mulde. As a consequence of these fatal effects of the flood in the entire Free State of Saxony among other things the flood prevention plan for the river Mulde in the district of Leipzig was worked out on behalf of the State Reservoir Administration of Saxony. The concept plans the construction of a bankside flood prevention wall. Based on the extreme monumental value of the silhouette of the town alternatives for the flood prevention wall as well as supplementary measures stood in the centre of the planning works. The strengthening of the exterior walls of the listed building of Alte Amtshauptmannschaft was the first project in Grimma for a gently integration of an historical building in the flood prevention system by keeping of the historical elevation of the façade.
The performance of masonry buildings under wind loads — The influence of the global effect on component response
Authors: Bakeer Tammam
Published: April 2011

The following contribution focuses on the global behaviour of masonry structures subjected to wind loads. It describes the interaction between the structural elements and their influences on the global behaviour. Numerical models based on discrete / finite element approach of different scales have been built for a typical terraced house masonry building.

The models have been used to investigate the contribution of each shear wall to the overall capacity of the structure, and to determine the portion of each from vertical/horizontal loads. The results give an insight into the interaction between the deformation of the slab and the rocking of the shear walls. The different performances between the model with rigid foundation and the model with elastic foundation have been compared.

Models for strips of the building have been built with an intention to deal with in‐plane behaviour separated from the influences of load distribution. A comparison of the results of the strip model with the results of the global model shows, that the strip model results are in safe side.

Das Verhalten von Mauerwerk unter Windlasten — Der Einfluss der Gesamteinwirkung auf die Reaktion einzelner Bauteile. Der folgende Beitrag konzentriert sich auf das globale Verhalten von Mauerwerksbauten unter Windlasten. Er beschreibt die Wechselwirkungen zwischen den einzelnen Strukturelementen und deren Einflüsse auf das Gesamtverhalten. Es sind numerische Modelle für ein typisches Reihenhaus aus Mauerwerk, die auf dem Diskrete‐/ Finite‐Elemente‐Ansatz basieren, in unterschiedlichen Ma�stäben erstellt worden.

Die Modelle dienten der Untersuchung des Beitrages jeder einzelnen Wandscheibe zur Gesamtwiderstandsfähigkeit des Bauwerks sowie ihres Anteils an der Ableitung der vertikalen und horizontalen Belastungen. Die Ergebnisse geben einen Einblick in die Wechselwirkung zwischen der Verformung der Deckenplatte und dem Kippen der Wandscheiben. Es wurde das unterschiedliche Verhalten eines Modells mit starrem Fundament und eines Modells mit elastischer Gründung verglichen.

Verschiedene Streifenmodelle des Gebäudes dienten dazu, das Schub‐Verhalten getrennt von den Einflüssen der Lastverteilung beschreiben zu können. Ein Vergleich der Ergebnisse des Streifenmodells mit den Ergebnissen des Gesamtmodells zeigt, dass das Streifenmodell auf der sicheren Seite liegt.
Development of minimally invasive medical tools using laser processing on cylindrical substrates
Authors: Haga Yoichi , Muyari Yuta , Goto Shoji , Matsunaga Tadao , Esashi Masayoshi
Published: April 2011

This paper reports micro‐fabrication techniques using laser processing on cylindrical substrates for the realization of high‐performance multifunctional minimally invasive medical tools of small size. A spring‐shaped shape memory alloy (SMA) micro‐coil with a square cross‐section has been fabricated by spiral cutting of a Ti‐Ni SMA tube with a femtosecond laser. A small‐diameter active bending catheter actuated by a hydraulic suction mechanism for intravascular minimally invasive diagnostics and therapy has also been developed. The catheter is made of Ti‐Ni superelastic alloy (SEA), which is processed by laser micromachining, and a silicone rubber tube that covers the outside of the SEA tube. The active catheter is effective for insertion into branches of blood vessels that diverge at acute angles where it is difficult to proceed. Multilayer metallization and patterning have been performed on glass tubes with 2‐ and 3‐mm external diameters using maskless lithography techniques with a laser exposure system. Using the laser soldering technique, integrated circuit parts have been mounted on a multilayer circuit patterned on a glass tube. These fabrication techniques will be effective for the realization of high‐performance multifunctional catheters, endoscopic tools, and implanted small capsules. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(1): 65–74, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21030
Identification of task model using piecewise affine systems with variable switching points and its application
Authors: Zanma Tadanao , Fuke Keizo , Ishida Muneaki
Published: April 2011

This paper considers a human‐operated task model based on identification techniques using switched systems expressed by mixed logical dynamical systems. In the system, each subsystem is expressed by a piecewise affine system. For a model to be identified, it is not easy to determine a number of subsystems in advance. In this paper, we propose a simultaneous identification technique which takes into account both a number of subsystems and parameters, so that a piecewise affine model of a human operation can be obtained. In addition, the obtained model is applied to automation. The effectiveness of the proposed method is illustrated by simulations and experiments. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(1): 46–54, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21079
A study on demand response effect of thermal storage air‐conditioning systems in consideration of electricity market prices
Authors: Omagari Yuko , Sugihara Hideharu , Tsuji Kiichiro
Published: April 2011

This paper evaluates the economic impact of the introduction of customer‐owned Thermal Storage Air‐conditioning (TSA) systems, in an electricity market, from the viewpoint of the load service entity (LSE). We perform simulations on the condition that several thousand customers install TSA systems and shift peak demand in an electricity market by one percent. Our numerical results indicate that the purchase cost of the LSE was reduced through load management of customers with TSA systems. The introduction of TSA systems also reduced the volatility of the market clearing price and reduced the whole‐trade cost in an electricity market. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(1): 18–27, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21091
A verification test result of islanding operation of a microgrid configured with new energy generators and a study of improvement of voltage control
Authors: Sumita Jiro , Nishioka Kojiro , Noro Yasuhiro , Ito Yozo , Yabuki Masanori , Kawakami Noriko
Published: April 2011

Verification test results of the isolated operation of a microgrid configured with some new energy generators at Aichi EXPO 2005 showed stable controllability without a rotating machine. However, improvement of voltage fluctuation with changing reactive power of loads had been hoped for. Some improvements of system voltage control had been implemented on the microgrid moved to Central Japan Airport City. This paper presents the results of verification testing of the improvement of voltage fluctuation in isolated operation with PAFC output power compensation control by NaS batteries, and also presents a simulation study of further improvement of the voltage control strategies of PAFC inverters. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 41–52, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21096
Effect of sensor information accuracy on condition‐based strategy of GIS/GCB maintenance
Authors: Kamei Mitsuhito , Takai Osamu
Published: April 2011

Condition‐Based Maintenance (CBM) is a new maintenance strategy and interest of utilities for reliable operation of aged power equipment. Although attempts have been made to apply CBM to various types of equipment, owing to insufficient understanding of the effect of the accuracy of condition information provided by sensors, the specification of reliable information is still not clear and CBM has not been widely applied in real power substations. The effect of the accuracy of condition information on the criteria of failure recognition is treated in this paper. The potential failure curve (P‐F curve) used in the original Reliability‐Centered Maintenance (RCM) concept is studied and its effect is explained. The explanation is confirmed by comparison of proved original sensors for CBM and existing sensors in an SF6 gas slow leakage detection experiment. The experiment indicates that SF6 gas leakage at levels of less than 0.1% per year might be detected with a CBM sensor. It is concluded that special efforts should be devoted to the sensitivity and long‐term stability of sensors for reliable operation of power substations under the CBM strategy. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 14–21, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21114
Construction of simulation model for OTEC plant using Uehara cycle
Authors: Goto Satoru , Motoshima Yoshiki , Sugi Takenao , Yasunaga Takeshi , Ikegami Yasuyuki , Nakamura Masatoshi
Published: April 2011

Ocean Thermal Energy Conversion (OTEC) converts heat energy into electricity using the 20 to 27 °C temperature difference between warm seawater at the surface and cold seawater in the depths. In this paper, a simulation model for an OTEC plant, which uses the Uehara cycle with an ammonia–water mixture as working fluid, is constructed based on the mass balance and the heat balance. A method of initial value determination for numerical simulation is developed. The accuracy of the simulation model was evaluated by comparison with the experimental results of an OTEC basic experimental equipment. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 1–13, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21138
Synthesis of a Range of Iodine(III) Compounds Directly from Iodoarenes
Authors: Merritt Eleanor A. , Olofsson Berit
Published: April 2011

The first direct synthesis of an alkynyl(phenyl)iodonium salt from iodobenzene and an unprotected alkyne is described. The synthesis of the corresponding alkenyl(phenyl)iodonium salt is achieved from the TMS‐alkyne, simply by means of changing the solvent. The one‐pot synthesis of 1‐arylbenziodoxolones and other iodine(III) compounds from iodine(I) precursors is also presented.
Evaluation of potential relationships between chemical contaminants in sediments and aquatic organisms from the lower Passaic River, New Jersey, USA
Authors: Iannuzzi Jacqueline , Butcher Matthew , Iannuzzi Timothy
Published: April 2011

The lower Passaic River, New Jersey, USA, a tidal tributary to Newark Bay and part of the New York and New Jersey Harbor Estuary, is contaminated with a variety of persistent organic pollutants (POPs) due to nearly two centuries of heavy industrialization and urbanization. Resident aquatic organisms are exposed to, and can bioaccumulate, a variety of chemical contaminants from sediments, water and other organisms. In the present study, the relationships between selected POPs detected in both surface sediments and aquatic organisms are examined statistically along with the efficacy of using empirical biota–sediment accumulation factors (BSAFs) to describe such relationships. Regression analyses were conducted on synoptic surface sediment POP data (0 to 15 cm in depth) and whole-body tissue POP data for three prominent organisms that reside in the river and which are important components of the food web: mummichog (Fundulus heteroclitus), blue crab (Callinectes sapidus), and white perch (Morone americana). Per the equilibrium partitioning theory on which the BSAF model is based, surface sediment data were normalized to total organic carbon and tissue data were normalized to lipid content for each organism. Normalized surface sediment concentrations were generally poorly correlated with normalized biota tissue concentrations. The BSAF model was not found to be a reliable means to predict concentrations of POPs in select lower Passaic River organisms, using surface sediment chemistry data. Environ. Toxicol. Chem. 2011; 30:1721–1728. © 2011 SETAC
The influence of emotional associations on the neural correlates of semantic priming
Authors: Sass Katharina , Habel Ute , Sachs Olga , Huber Walter , Gauggel Siegfried , Kircher Tilo
Published: April 2011

Emotions influence our everyday life in several ways. With the present study, we wanted to examine the impact of emotional information on neural correlates of semantic priming, a well‐established technique to investigate semantic processing. Stimuli were presented with a short SOA of 200 ms as subjects performed a lexical decision task during fMRI measurement. Seven experimental conditions were compared: positive/negative/neutral related, positive/negative/neutral unrelated, nonwords (all words were nouns). Behavioral data revealed a valence specific semantic priming effect (i.e., unrelated > related) only for neutral and positive related word pairs. On a neural level, the comparison of emotional over neutral relations showed activation in left anterior medial frontal cortex, superior frontal gyrus, and posterior cingulate. Interactions for the different relations were located in left anterior part of the medial frontal cortex, cingulate regions, and right hippocampus (positive > neutral + negative) and left posterior part of medial frontal cortex (negative > neutral + positive). The results showed that emotional information have an influence on semantic association processes. While positive and neutral information seem to share a semantic network, negative relations might induce compensatory mechanisms that inhibit the spread of activation between related concepts. The neural correlates highlighted a distributed neural network, primarily involving attention, memory and emotion related processing areas in medial fronto‐parietal cortices. The differentiation between anterior (positive) and posterior part (negative) of the medial frontal cortex was linked to the type of affective manipulation with more cognitive demands being involved in the automatic processing of negative information. Hum Brain Mapp, 2012. © 2010 Wiley Periodicals, Inc.
Topography, power, and current source density of theta oscillations during reward processing as markers for alcohol dependence
Authors: Kamarajan Chella , Rangaswamy Madhavi , Manz Niklas , Chorlian David B. , Pandey Ashwini K. , Roopesh Bangalore N. , Porjesz Bernice
Published: April 2011

Recent studies have linked alcoholism with a dysfunctional neural reward system. Although several electrophysiological studies have explored reward processing in healthy individuals, such studies in alcohol‐dependent individuals are quite rare. The present study examines theta oscillations during reward processing in abstinent alcoholics. The electroencephalogram (EEG) was recorded in 38 abstinent alcoholics and 38 healthy controls as they performed a single outcome gambling task, which involved outcomes of either loss or gain of an amount (10 or 50¢) that was bet. Event‐related theta band (3.0–7.0 Hz) power following each outcome stimulus was computed using the S‐transform method. Theta power at the time window of the outcome‐related negativity (ORN) and positivity (ORP) (200–500 ms) was compared across groups and outcome conditions. Additionally, behavioral data of impulsivity and task performance were analyzed. The alcoholic group showed significantly decreased theta power during reward processing compared to controls. Current source density (CSD) maps of alcoholics revealed weaker and diffuse source activity for all conditions and weaker bilateral prefrontal sources during the Loss 50 condition when compared with controls who manifested stronger and focused midline sources. Furthermore, alcoholics exhibited increased impulsivity and risk‐taking on the behavioral measures. A strong association between reduced anterior theta power and impulsive task‐performance was observed. It is suggested that decreased power and weaker and diffuse CSD in alcoholics may be due to dysfunctional neural reward circuitry. The relationship among alcoholism, theta oscillations, reward processing, and impulsivity could offer clues to understand brain circuitries that mediate reward processing and inhibitory control Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.
The obese brain: Association of body mass index and insulin sensitivity with resting state network functional connectivity
Authors: Kullmann Stephanie , Heni Martin , Veit Ralf , Ketterer Caroline , Schick Fritz , Häring Hans‐Ulrich , Fritsche Andreas , Preissl Hubert
Published: April 2011

Obesity is a key risk factor for the development of insulin resistance, Type 2 diabetes and associated diseases; thus, it has become a major public health concern. In this context, a detailed understanding of brain networks regulating food intake, including hormonal modulation, is crucial. At present, little is known about potential alterations of cerebral networks regulating ingestive behavior. We used “resting state” functional magnetic resonance imaging to investigate the functional connectivity integrity of resting state networks (RSNs) related to food intake in lean and obese subjects using independent component analysis. Our results showed altered functional connectivity strength in obese compared to lean subjects in the default mode network (DMN) and temporal lobe network. In the DMN, obese subjects showed in the precuneus bilaterally increased and in the right anterior cingulate decreased functional connectivity strength. Furthermore, in the temporal lobe network, obese subjects showed decreased functional connectivity strength in the left insular cortex. The functional connectivity magnitude significantly correlated with body mass index (BMI). Two further RSNs, including brain regions associated with food and reward processing, did not show BMI, but insulin associated functional connectivity strength. Here, the left orbitofrontal cortex and right putamen functional connectivity strength was positively correlated with fasting insulin levels and negatively correlated with insulin sensitivity index. Taken together, these results complement and expand previous functional neuroimaging findings by demonstrating that obesity and insulin levels influence brain function during rest in networks supporting reward and food regulation. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.