bluuebunny/crossref_metadata_2025 huggingface dataset:
Current density in a model of a human body with a conductive implant exposed to ELF electric and magnetic fields
Authors: Valič Blaž , Gajšek Peter , Miklavčič Damijan
Published: May 2009

A numerical model of a human body with an intramedullary nail in the femur was built to evaluate the effects of the implant on the current density distribution in extremely low frequency electric and magnetic fields. The intramedullary nail was chosen because it is one of the longest high conductive implants used in the human body. As such it is expected to alter the electric and magnetic fields significantly. The exposure was a simultaneous combination of inferior to superior electric field and posterior to anterior magnetic field both alternating at 50 Hz with the values corresponding to the ICNIRP reference levels: 5000 V m−1 for electric field and 100 µT for magnetic flux density. The calculated current density distribution inside the model was compared to the ICNIRP basic restrictions for general public (2 mA m−2). The results show that the implant significantly increases the current density up to 9.5 mA m−2 in the region where it is in contact with soft tissue in the model with the implant in comparison to 0.9 mA m−2 in the model without the implant. As demonstrated the ICNIRP basic restrictions are exceeded in a limited volume of the tissue in spite of the compliance with the ICNIRP reference levels for general public, meaning that the existing safety limits do not necessarily protect implanted persons to the same extent as they protect people without implants. Bioelectromagnetics 30:591–599, 2009. © 2009 Wiley‐Liss, Inc.
A new biocatalyst: Penicillin G acylase immobilized in sol‐gel micro‐particles with magnetic properties
Authors: Bernardino Susana M. S. A. , Fernandes Pedro , Fonseca Luís P.
Published: May 2009

The present work focuses on the development and basic characterization of a new magnetic biocatalyst, namely penicillin G acylase (PGA), immobilized in sol‐gel matrices with magnetic properties, ultimately aimed for application in cephalexin (CEX) synthesis. A mechanically stable carrier, based on porous xerogels silica matrixes starting from tetramethoxysilane (TMOS), was prepared leading to micro‐carriers with medium sized particles of 30 μm, as determined by scanning electron microscopy. An immobilization yield of 95–100% and a recovered activity of 50–65% at 37°C, as determined by penicillin G (PG) hydrolysis (pH STAT method), were observed. These results clearly exceed those reported in a previous work on PGA immobilization in sol‐gel, where only 10% of activity was recovered. The values of activity were kept constant for 6 months. Immobilized PGA (682 U/gdry weight) retained high specific activity throughout ten consecutive runs for PG hydrolysis, suggesting adequate biocatalyst stability. The CEX synthesis was performed at 14°C, using the free and immobilized PGA in aqueous medium. Phenylglycine methyl ester was used as acyl donor at 90 mM and 7‐aminodeacetoxycephalosporanic acid was the limiting substrate at 30 mM. The CEX stoichiometric yield after 1‐h reaction was close to 68% (23 mM CEX/h) and 65% (19 mM CEX/h), respectively.
Cell‐free synthesis of functional aquaporin Z in synthetic liposomes
Authors: Hovijitra Norman T. , Wuu Jessica J. , Peaker Boris , Swartz James R.
Published: May 2009

The challenges involved in producing sufficient quantities of aquaporins for precise biophysical characterization have limited our knowledge of this important class of molecules. This article describes a cell‐free protein synthesis method for producing high concentrations of the E. coli water transporter, aquaporin Z (AqpZ), in synthetic liposomes. To our knowledge, this is the first report of in vitro synthesis of a membrane protein directly into synthetic liposomes with verified function, (i.e., transport activity and selectivity). Titration of DOPC lipid vesicles added to the cell‐free reaction show that production yields of active AqpZ are dependent on the concentration of DOPC lipid vesicles added to the cell‐free reaction, with 224 ± 24 lipids required per aquaporin monomer. Supplementation of the signal recognition particle receptor (FtsY) to the cell‐free reaction increases production of vesicle‐associated AqpZ but not active AqpZ. Cell‐free reactions using 7 mg/mL lipids that were not supplemented with FtsY produced 507 ± 11 µg/mL of vesicle‐associated AqpZ that exhibited a specific water transport activity of (2.2 ± 0.3) × 10−14 cm3 s−1 monomer−1. Proteinase K protection, activation energy determination, and selectivity against glycerol and urea transport also confirmed the production of correctly folded AqpZ. This technique is capable of producing milligram quantities of aquaporin that can be readily assayed for function, facilitating biophysical characterization and high‐throughput analysis. Biotechnol. Bioeng. 2009; 104: 40–49 © 2009 Wiley Periodicals, Inc.
Bioproduction of the aroma compound 2‐Phenylethanol in a solid–liquid two‐phase partitioning bioreactor system by Kluyveromyces marxianus
Authors: Gao Fang , Daugulis Andrew J.
Published: May 2009

The rose‐like aroma compound 2‐phenylethanol (2‐PE) is an important fragrance and flavor ingredient. Several yeast strains are able to convert l‐phenylalanine (l‐phe) to 2‐PE among which Kluyveromyces marxianus has shown promising results. The limitation of this process is the low product concentration and productivity primarily due to end product inhibition. This study explored the possibility and benefits of using a solid–liquid Two‐Phase Partition Bioreactor (TPPB) system as an in situ product removal technique. The system applies polymer beads as the sequestering immiscible phase to partition 2‐PE and reduce the aqueous 2‐PE concentration to non‐inhibitory levels. Among six polymers screened for extracting 2‐PE, Hytrel® 8206 performed best with a partition coefficient of 79. The desired product stored in the polymer was ultimately extracted using methanol. A 3 L working volume solid–liquid batch mode TPPB using 500 g Hytrel® as the sequestering phase generated a final overall 2‐PE concentration of 13.7 g/L, the highest reported in the current literature. This was based on a polymer phase concentration of 88.74 g/L and aqueous phase concentration of 1.2 g/L. Even better results were achieved via contact with more polymers (approximately 900 g) with the aqueous phase applying a semi‐continuous reactor configuration. In this system, a final 2‐PE concentration (overall) of 20.4 g/L was achieved with 1.4 g/L in the aqueous and 97 g/L in the polymer phase. The overall productivities of these two reactor systems were 0.38 and 0.43 g/L h, respectively. This is the first report in the literature of the use of a polymer sequestering phase to enhance the bioproduction of 2‐PE, and exceeds the performance of two‐liquid phase systems in terms of productivity as well as ease of operation (no emulsions) and ultimate product recovery. Biotechnol. Bioeng. 2009; 104: 332–339 © 2009 Wiley Periodicals, Inc.
Reversal of coenzyme specificity of 2,3‐butanediol dehydrogenase from Saccharomyces cerevisae and in vivo functional analysis
Authors: Ehsani Maryam , Fernández Maria R. , Biosca Josep A. , Dequin Sylvie
Published: May 2009

Saccharomyces cerevisiae NAD(H)‐dependent 2,3‐butanediol dehydrogenase (Bdh1), a medium chain dehydrogenase/reductase is the main enzyme catalyzing the reduction of acetoin to 2,3‐butanediol. In this work we focused on altering the coenzyme specificity of Bdh1 from NAD(H) to NADP(H). Based on homology studies and the crystal structure of the NADP(H)‐dependent yeast alcohol dehydrogenase Adh6, three adjacent residues (Glu221, Ile222, and Ala223) were predicted to be involved in the coenzyme specificity of Bdh1 and were altered by site‐directed mutagenesis. Coenzyme reversal of Bdh1 was obtained with double Glu221Ser/Ile222Arg and triple Glu221Ser/Ile222Arg/Ala223Ser mutants. The performance of the triple mutant for NADPH was close to that of native Bdh1 for NADH. The three engineered mutants were able to restore the growth of a phosphoglucose isomerase deficient strain (pgi), which cannot grow on glucose unless an alternative NADPH oxidizing system is provided, thus demonstrating their in vivo functionality. These mutants are interesting tools to reduce the excess of acetoin produced by engineered brewing or wine yeasts overproducing glycerol. In addition, they represent promising tools for the manipulation of the NADP(H) metabolism and for the development of a powerful catalyst in biotransformations requiring NADPH regeneration. Biotechnol. Bioeng. 2009; 104: 381–389 © 2009 Wiley Periodicals, Inc.
Anatomical variations of the upper thoracic sympathetic chain
Authors: Zhang Bensi , Li Zhuang , Yang Xinwen , Li Guangzhong , Wang Yong , Cheng Jiamao , Tang Ximin , Wang Fan
Published: May 2009

The aim is to clearly delineate the upper thoracic sympathetic chains and neural connections between the chains and ventral rami of the thoracic nerves, and to provide an anatomical foundation for successful upper thoracic sympathicotomy for treating upper essential hyperhidrosis. The upper thoracic sympathetic chains, upper five intercostal nerves, and neural connections between them in 50 halves of 25 adult cadavers have been dissected, measured, and mapped. The stellate ganglion had an incidence of 80%. The second to the fourth thoracic sympathetic ganglia were commonly located in the corresponding intercostal spaces with the presence of 92%, 68%, and 50%, respectively. The incidence of the first and second intercostal rami was 40% and 6%, and that of the ascending or descending rami from the second, third and fourth ganglia was 54%, 24%, and 14%, respectively. Additional rami communicantes joined the ventral ramus of the 1st thoracic nerve proximal to the point where the latter gave a branch to the brachial plexus. The farthest horizontal distance from the sympathetic chain to the junction between the additional rami communicantes and the second to the fourth intercostal nerves was 29.1 mm. Only 16% of cadavers had similar anatomy bilaterally. Anatomical variations of the upper thoracic sympathetic trunk in relation to intercostal nerves, which may be one of the causes resulting in surgical failures and recurrences, were striking. Attention should be given to such anatomical variations when planning thoracic sympathicotomy. Clin. Anat. 22:595–600, 2009. © 2009 Wiley‐Liss, Inc.
Dealing with dynamic changes in time critical decision‐making for MOUT simulations
Authors: Ting Shang‐Ping , Zhou Suiping
Published: May 2009

Generating realistic behaviors for the non‐player characters (also known as bots) is an important task for Military Operations on Urban Terrain (MOUT) simulations. Most of the current bots reasoning models are based on complete rational analysis of all alternatives. However, such models may not be adequate in time critical and uncertain situations. In such situations, due to time constraints and incomplete information, humans rely mainly on experience rather than some structured analysis of the given situation to make decisions. In our previous work, we have developed SNAP, a time critical decision‐making framework which aims to imitate human decision‐making processes for MOUT simulations. A major limitation that we found about SNAP is its difficulty in dealing with dynamic changes in MOUT simulations. In this paper, we propose to address this problem by incorporating a novel feature of expectations into SNAP. The effectiveness of this new feature is assessed with Twilight City, a virtual environment for MOUT simulations. Experimental results show that our expectation model works well in dealing with dynamic changes in MOUT. Copyright © 2009 John Wiley & Sons, Ltd.
Real‐time dynamics for geometric textures in shell
Authors: Huang Jin , Sun Hanqiu , Zhou Kun , Bao Hujun
Published: May 2009

Embedding geometric textures in a shell space around an arbitrary surface has been a popular way to add highly detailed geometric details and enhance visual richness in graphics community, but the dynamic effects of geometric textures have not been modeled and simulated. In this paper, we introduce an efficient algorithm for deforming geometric textures with dynamic effects. The algorithm consists of two steps. First, it computes a deformed shell space by optimizing a material related energy function, which is then used to evaluate the equilibrium position of the geometric texture. Second, an explicit time integration scheme is applied for vibrating the geometric texture around its equilibrium position. Users can deform the geometric textures by dragging its vertices directly, and the dynamic behavior of the geometric textures can be changed by adjusting several material parameters. The dynamic simulation of geometric textures can be easily implemented on GPU and runs at real‐time rates. Copyright © 2009 John Wiley & Sons, Ltd.
Performance‐driven motion choreographing with accelerometers
Authors: Liang Xiubo , Li Qilei , Zhang Xiang , Zhang Shun , Geng Weidong
Published: May 2009

Live performance is an intuitive way to naturally draft the desired motion in the choreographer's mind. In this paper we present a novel approach to choreographing motions by live performance captured with degree of freedom (3‐DOF) accelerometers. The process begins by placing the accelerometers on the user's limbs according to the pre‐specified positions. The computer then recognizes the performed actions using Hidden Markov Model (HMM), which is pre‐trained by the acceleration data samples automatically generated from a pre‐segmented motion capture database. At last, the captured actions are further synthesized with motion retiming and exaggeration based on the acceleration signals from the accelerometers. This method can intuitively rapid‐prototype the choreographed motions for pre‐production of animation, the avatar control in virtual reality and game‐like scenarios, etc. The experimental results show that it can effectively recognize actions with spatial‐time variance, and is easy‐to‐use especially for a novice with little experience. Copyright © 2009 John Wiley & Sons, Ltd.
Functionalization of Boron Dipyrrin (BODIPY) Dyes through Iridium and Rhodium Catalysis: A Complementary Approach to α‐ and β‐Substituted BODIPYs
Authors: Chen Jinping , Mizumura Masatoshi , Shinokubo Hiroshi , Osuka Atsuhiro
Published: May 2009

Two series of BODIPY dyes with substituents either in the α positions or in the β positions and different conjugation lengths were synthesized by means of iridium‐catalyzed borylation and rhodium‐catalyzed Heck‐type addition (see scheme). The α‐ and β‐substituted series show completely different photophysical properties. BODIPY=boron dipyrrin.

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Iridium‐catalyzed direct borylation has been applied to meso‐substituted dipyrromethane and boron dipyrrin (BODIPY) dyes. Borylation is highly regioselective and complementary: it occurs exclusively at the α position for meso‐mesityldipyrromethane and at the β positions for meso‐mesityl BODIPY dye. This regioselective borylation enables a variety of α‐ and β‐substituted BODIPY dyes to be synthesized. Introduction of α,β‐enoate and α,β,γ,δ‐dienoate functions into BODIPY dyes at the α or β positions was achieved by rhodium‐catalyzed Heck‐type addition of the borylated compounds to acrylate and 2,4‐pentadienoate esters. This functionalization has a significant effect on the electronic properties of BODIPY dyes, as seen in substantial redshift of the absorption and emission spectra. Comparative studies showed that the α‐ and β‐substituted series of BODIPY dyes show substantially different photophysical properties, and thus the importance of the position to be functionalized is highlighted.
Bonding or Nonbonding? Description or Explanation? “Confinement Bonding” of He@adamantane
Authors: Wang Shu‐Guang , Qiu Yi‐Xiang , Schwarz W. H. Eugen
Published: May 2009

Insight into bonding phenomenadepends on whether one analyzes the whole bond‐formation process or just the final product. Examination of the formation of the inclusion complex He@adamantane by energy partitioning reveals that the high energy cost of “He bonding” originates in strong HeC Pauli repulsions. The postulate of attractive HeC bonds requires a very specific view.

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Different insights into chemical phenomena are obtained by analyzing the whole process (comparing three or more points, thereby explaining the atomistic mechanism) or only the final product (yielding an interesting fingerprint of the result). The viewpoint depends also on whether one analyzes the wavefunctions according to notions grounded in chemical experience or along physically well‐defined formal concepts. Bond energies can only be understood upon comparing both ends of the formation process from fragments to molecule. We examine the formation of the inclusion complex He@adamantane. The large antibonding energy expense is partitioned into four physical contributions according to chemical concepts. Introduction of the He atom into an undeformed adamantane cage leads to a large increase of Pauli repulsion; this is partly moderated by electrostatic overlap attraction and by electronic and nuclear relaxations. The IUPAC definition of bonding comprises this antibonding interaction, since a (meta)stable complex is formed. We call it “confinement bonding”. Single‐point analyses of the bond‐formation product can only yield one‐sided characterizations. Any analysis depends on its prescription, which should always be specified in order to avoid controversies based on a mix up of unlike concepts.
Controlled Assembly of Au, Ag, and Pt Nanoparticles with Chitosan
Authors: Hong Min , Wu Linlin , Tian Liangfei , Zhu Jin
Published: May 2009

Working on the chain gang: A simple method for the controlled assembly of metal nanoparticles (Au, Ag, and Pt) into 1D chains (see figure) has been developed based on the electrostatic interaction of negatively charged carboxylic groups on the citrate ions surrounding the NPs and the positively charged chitosan polymer.

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A simple method for the controlled assembly of metal nanoparticles into one‐dimensional chains has been developed. The chain‐formation process could be accounted for by the electrostatic interaction of the negatively charged carboxylic groups on the citrate ions surrounding metal nanoparticles and the positively charged chitosan polymer. Three representative types of nanoparticles comprising Au, Ag, and Pt, respectively, have been used to illustrate the generic applicability of the proposed methodology. Facile control of the chain length of the nanoparticle assembly could be achieved by adjusting the concentrations of negatively or positively charged species. We anticipate the ready adaptability of the methodology to nanoparticles of more complex compositions.
Lithium Diisopropylamide‐Mediated Carbolithiation Reactions of Vinylidenecyclopropanes and Further Transformations of the Adducts
Authors: Lu Jian‐Mei , Shi Min
Published: May 2009

Synthetic methods: Lithium diisopropylamide‐mediated highly selective carbolithiation reactions of vinylidenecyclopropanes are described and further transformations of these adducts were performed in the presence of Lewis or Brønsted acids (see scheme for sample reactions).

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Highly stereo‐ and regioselective carbolithiation reactions of vinylidenecyclopropanes 1 were realized by treatment with lithium diisopropylamide (LDA) in THF and by quenching with various electrophiles such as aryl or aliphatic aldehydes, ketones, enones or propargyl bromide. Transformation of these adducts such as vinylcyclopropenes and allenols was also performed in the presence of Lewis acid or Brønsted acid to provide the fused and conjugated aromatic products in good to high yields under mild conditions.
Heteroaromatic Tosylates as Electrophiles in Regioselective Mizoroki–Heck‐Coupling Reactions with Electron‐Rich Olefins
Authors: Gøgsig Thomas M. , Lindhardt Anders T. , Dekhane Mouloud , Grouleff Julie , Skrydstrup Troels
Published: May 2009

Easy and direct: Regioselective Mizoroki–Heck‐coupling reactions using heteroaromatic tosylates as electrophiles were achieved, thus providing direct and easy access to highly functionalized α‐heteroarylvinyl amides and ethers.

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Heteroaromatic 2‐pyridyl tosylates were successfully applied as electrophiles in palladium(0)‐catalyzed Mizoroki–Heck‐coupling reactions to electron‐rich olefins with complete α‐regioselectivity. This protocol represents a general strategy for the application of pyridyl tosylates and mesylates in the Mizoroki–Heck coupling. The catalytic system also proved adaptable to changes in the heteroaromatic core as well as large‐scale applications. Finally, the synthetic utility of the functionalized α‐heteroarylvinyl amides was established providing straightforward access to highly functionalized heteroaromatic compounds including chiral benzylic amide derivatives.
Gold‐Catalyzed Stereocontrolled Synthesis of 2,3‐Bis(acetoxy)‐1,3‐dienes
Authors: Huang Xiaogen , de Haro Teresa , Nevado Cristina
Published: May 2009

Change the ligand, change the stereochemistry: 2,3‐Bis(acetoxy)‐1,3‐dienes are obtained in a stereocontrolled manner by a novel tandem 1,2‐/1,2‐bis(acetoxy) rearrangement (see scheme, R1 and R2 are δ+ stabilizing). Upon stabilization of the reaction intermediates, the ligand attached to gold controls the stereochemistry of the alkene in the second acetate migration, that is, N‐heterocyclic carbenes (NHC) favor cis alkenes, whereas phosphine ligands selectively afford trans olefins.

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Application of Copper(II)–Dipyridylphosphine Catalyst in the Asymmetric Hydrosilylation of Simple Ketones in Air
Authors: Zhang Xi‐Chang , Wu Yan , Yu Feng , Wu Fei‐Fei , Wu Jing , S. C. Chan Albert
Published: May 2009

Ask a copper: A copper(II) salt/chiral dipyridylphosphine/PhSiH3 system (see scheme) acts as a very effective and practical catalyst for the asymmetric reduction of heteroaromatic and other types of ketones in air with good‐to‐excellent enantioselectivities (up to 94 %), giving many chiral alcohols that are intermediates for physiologically active compounds. Remarkable temperature effects were observed for some heteroaromatic ketones.

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Nanostrukturierte Kern‐Schale‐Katalysatoren für PEM‐Brennstoffzellen – Hochaktive Materialien durch partielle Entlegierung
Authors: Strasser P.
Published: May 2009

Die elektrochemische Umwandlung von Sauerstoff zu Wasser sowie ihre Umkehrreaktion gehören im Moment zu den größten Herausforderungen der Wissenschaft und Forschung zum Zwecke einer effizienten und nachhaltigen Nutzung elektrochemischer Energieumwandlungsprozesse basierend auf Brennstoffzellen oder der Elektrolyse von Wasser. Reines Platin – der am häufigsten verwendete Kathodenkatalysator für die Sauerstoffreduktion in Brennstoffzellen – ist teuer und nicht ausreichend aktiv und stabil. Vielversprechend ist ein neues Katalysatorkonzept basierend auf einem sehr Pt armen nanostrukturierten Kern‐Schale‐Prinzip. Durch selektives partielles Entlegieren, d. h. elektrochemische Entfernung von unedlen Metallatomen aus der Oberfläche einer nichtedelmetallreichen Pt‐Legierung („Dealloying”︁), wird eine Pt reiche Schale auf einem nichtedelmetallreichen Kern von definierbarer Dicke gebildet, die eine gezielte Steuerbarkeit von katalytischer Aktivität ermöglicht. Eine Reduzierung der Pt‐Menge in der Zellkathode um mehr als 80 % ist dabei möglich.
Rabs and cancer cell motility
Authors: Tang Bor Luen , Ng Ee Ling
Published: May 2009

The Rab family of small GTPases functions in regulating vesicular transport in all eukaryotes. In the past few years, several important reports have linked some members of the Rab family to intriguing mechanistic aspects of cancer cell migration and invasiveness. Rab5 and Rab21 associate with α‐integrin subunits and modulate their endosomal traffic and subcellular localization. Expression of the latter enhances adhesion and migration of certain cancer cell types. Rab25 has been functionally linked to tumor progression and the invasiveness of some epithelial cancers. Rab25 promotes invasive migration of cells in three‐dimensional microenvironments by associating with α5β1 integrin, and directing its recycling to dynamic ruffling protrusions at the migrating cell front. Acting directly, or through its effector, the Rab‐coupling protein, Rab25 could potentially engage both integrin and epidermal growth factor receptor and enhance their oncogenic recycling and signaling. Tumor invasiveness may also be modulated by Rab8‐mediated exocytic traffic of MT1‐matrix metalloproteinase, with the latter's activity likely influenced by interaction with the mammalian suppressor of Sec4 (Mss4), a Rab8 guanine nucleotide exchange factor, and integrin. We discuss highlights in the recent literature that point towards a role for Rab‐mediated membrane traffic in cancer cell migration and invasion. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Antisense Drug Technology: Principles, Strategies, and Applications. Edited by Stanley T. Crooke.
Authors: Fluiter Kees
Published: May 2009

CRC Press, Boca Raton 2007. xvii+825 pp., hardcover $ 239.95.—ISBN 978‐0‐84938‐796‐8
Spin–Spin Coupling Constants Transmitted through IrH⋅⋅⋅HN Dihydrogen Bonds
Authors: Olejniczak Malgorzata , Pecul Magdalena
Published: May 2009

Relativity matters: Calculations of NMR shielding tensors and spin–spin coupling constants transmitted through IrH⋅⋅⋅HN dihydrogen bonds are presented. The picture shows one of the simplified models employed. It is shown that the spin–orbit relativistic effects influence the NMR shielding constants far more than the spin–spin coupling constants.

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We present calculations of NMR shielding tensors and spin–spin coupling constants transmitted through IrH⋅⋅⋅HN dihydrogen bonds. For this purpose, three six‐coordinated complexes of iridium have been selected as models of heavy metal complexes and their NMR properties have been calculated within the DFT‐ZORA (density functional theory zeroth‐order regular approximation) methodology. The influence of intramolecular interactions between hydrogen atoms from IrH3 and NH2 groups (including both single dihydrogen bonding and bifurcated hydrogen bonding) on the NMR properties is discussed and the results are compared with the experimental observations. In complexes where dihydrogen bonding occurs, the calculated value of “through‐space” 1hJ(HaHb) is in the range 1.6–7.9 Hz [depending on the model, but with R(HaHb)<2.0 Å], while the experimental values are 2–5 Hz for similar HaHb distances. The 2hJ(NH) coupling is also sizeable, ranging from approximately −5.1 Hz for dihydrogen bonds of 2 Å up to −7.1 Hz for very short (1.6 Å) dihydrogen bonds, and should therefore be experimentally accessible when using 15N‐labelled compounds. The dihydrogen‐bond transmitted spin–spin coupling constants 1hJ(HH) and 2hJ(NH) and the shielding tensor of the Ha atom are the most sensitive probes of the HaHb distance, which potentially makes them attractive tools to determine the structure of molecules. The main conclusions are qualitatively similar to those drawn from nonrelativistic calculations in small inorganic complexes, and the spin–orbit relativistic effects influence the NMR shielding constants far more than the spin–spin coupling constants.
Security and delay issues in SIP systems
Authors: Callegari Christian , Garroppo Rosario G. , Giordano Stefano , Pagano Michele
Published: May 2009

The deployment of multimedia over IP (MoIP), and in particular voice over IP services, requires to solve new security issues they introduce, before completely exploiting the great opportunities they offer to telecommunication market. Furthermore, the implementation of various security measures can cause a marked deterioration in quality of service, which is fundamental to the operation of an MoIP network that meets users' quality expectations. In particular, because of the time‐critical nature of MoIP and its low tolerance for disruption and packet loss, many security measures implemented in traditional data networks are simply not applicable in their current form. This paper presents an analysis of the security options of Session Initiation Protocol‐ (SIP)‐based MoIP architecture aimed at evaluating their impact on delay. In particular, each security option is analyzed in terms of clock cycles needed to perform the related operations. This parameter could be used to estimate the delay introduced by the security mechanisms. Moreover the paper proposes a rigorous definition of five security profiles, which provide different levels of security to a MoIP system. Copyright © 2009 John Wiley & Sons, Ltd.
Cell survival and apoptosis‐related molecules in cancer cells in effusions: A comprehensive review
Authors: Kleinberg Lilach , Davidson Ben
Published: May 2009

Spreading of cancer cells to effusions is a manifestation of advanced disease, for which the chances of achieving cure using conventional treatment are low. This emphasizes both the importance of improving early detection and the need for developing targeted therapy modes. Such approaches should be based on characterization of the antiapoptotic, survival and drug resistance mechanisms of the metastatic cells in addition to analysis of the primary tumor. This review presents current knowledge regarding the expression and clinical role of cell survival and apoptosis‐related molecules in nonhematological cancers in effusions. Differences in the anatomic site‐related expression and clinical role of these proteins are additionally discussed. The data presented highlight the complexity of the multiple molecular pathways that mediate tumor cell survival within the serosal cavities. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
The use of thrombelastography to determine coagulation status in severe anorexia nervosa: A case series
Authors: Gaudiani Jennifer L. , Kashuk Jeffry L. , Chu Eugene S. , Narayanan Vignesh , Mehler Philip S.
Published: May 2009

Objective:

Hospitalized patients with severe anorexia nervosa (AN) frequently have a complex coagulation profile, with elements of hypocoagulability‐thrombocytopenia and elevated international normalized ratio (INR) and elements of hypercoagulability‐usually manifested as immobility, which is either due to their marked weakness or from enforced degrees of bed rest to minimize energy expenditure. Hospitalized medical patients have been shown to have appropriate prophylaxis for venous thromboembolic (VTE) disease in only 40% of cases.

Method:

A simple test that could evaluate the overall coagulation profile of these patients would help guide appropriate VTE prophylaxis. The thrombelastogram is a blood test that evaluates the full dynamic process of hemostasis.

Results:

The study of patients did not reveal evidence of being hypocoagulable and thus should be considered for VTE prophylaxis.

Discussion:

We report on three cases of young women with severe AN and weakness, hospitalized for closely monitored refeeding, in whom the thromboelastogram was used to evaluate the coagulation status of the patient and assist in guiding therapy. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
A‐Frame‐Containing Organometallic Oligomers Constructed From Homo‐ and Heterobimetallic M(μ‐dppm)2M′ (M/M′ = Pd, Pt) Building Blocks
Authors: Clément Sébastien , Aly Shawkat M. , Husson Jérôme , Fortin Daniel , Strohmann Carsten , Knorr Michael , Guyard Laurent , Abd‐El‐Aziz Alaa S. , Harvey Pierre D.
Published: May 2009

The homo‐ and heterodinuclear complexes XM(μ‐dppm)2M′X (M = M′ = Pd, X = Cl 1a; M = M′ = Pd, X = I 1b; M = Pd, M′ = Pt, X = Cl 2a; M = Pd, M′ = Pt, X = I 2b; M = M′ = Pt, X = Cl 3a; M = M′ = Pt, X = I 3b) react with the diisocyanide ligand 1,2‐bis(2‐isocyanophenoxy)ethane (diNC) or the more soluble 1,2‐bis(2‐isocyano‐4‐tert‐butylphenoxy)ethane (tBudiNC) in a 1:1 ratio to provide the thermally stable polymeric materials 4–9 {[XM(μ‐dppm)2M′(μ‐CN‐C6H3R‐2‐OCH2CH2O‐2‐C6H3R‐NC)]X}n (M = M′ = Pd, R = H, X = Cl 4a, I 4b; R = tBu, X = Cl 7; M = M′ = Pt, R = H, X = Cl 5a, I 5b; R = tBu, X = Cl 8; M = Pd, M′ = Pt, R = H, X = Cl 6a, I 6b; R = tBu, X = Cl 9). These A‐frame‐containing materials have been characterized in solution or in the solid state by 31P NMR (MAS) spectroscopy, elemental analysis, MALDI‐TOF, DSC, TGA, IR and T1/NOE [31P NMR spin‐lattice relaxation time and nuclear Overhauser enhancement constant (NOE) measurements]. The IR, Raman [ν(CN) bridging vs. terminal] and NMR spectroscopic data reveal the presence of an A‐frame structure for these new materials. Evidence of an oligomer (including at least two units, determined by T1/NOE experiments) – polymer equilibrium in solution was obtained at room temperature. These polymers are luminescent (phosphorescence) at 77 K in solution and in the solid state, exhibiting broad emission bands in the 500–800 nm range. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis, Structures, and Excited‐State Geometries of Alkynylgold(I) Complexes
Authors: Gao Lei , Partyka David V. , Updegraff James B. , Deligonul Nihal , Gray Thomas G.
Published: May 2009

A series of phosphane‐ and (N‐heterocyclic carbene)gold(I) complexes were prepared by deprotonation of terminal alkyne precursors and reaction with the corresponding gold(I) chlorides. Some ten new compounds are reported; these are characterized by multinuclear NMR, optical spectroscopy, and elemental analysis. Crystallographic characterization is reported for five complexes. Organogold species bearing conjugated aryl substituents on the alkynyl ligand are luminescent. Density‐functional theory calculations on a model complex suggest that emission and the first several absorption transitions result from excited states dominated by the arylacetylide ligand. Excited‐state geometry optimization finds that the lowest‐energy triplet state bears linear, two‐coordinate gold(I) with a miniscule lengthening of the alkynyl carbon–carbon bond. An unusual triplet excited state having a bent geometry at gold lies at higher energy in arylacetylide complexes. For the model terminal acetylideMe3PAuC≡CH, the calculations find this bent state to be the lowest‐energy triplet.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Spicochalasin A and New Aspochalasins from the Marine‐Derived Fungus Spicaria elegans
Authors: Lin Zhenjian , Zhu Tianjiao , Wei Hongjuan , Zhang Guojian , Wang Hui , Gu Qianqun
Published: May 2009

Different culture conditions directed by the OSMAC (one strain‐many compounds) approach drastically modified the metabolites of the fungus Spicaria elegans, which yielded the novel spicochalasin A (1), five new aspochalasins M–Q (2–6), and two known aspochalasins (7 and 8). The gross structures of 1–6 were elucidated by 1D and 2D NMR and MS methods, and their absolute configurations were determined by X‐ray diffraction and the Mosher ester method. Spicochalasin A (1) has a unique pentacyclic system and was found to be moderately cytotoxic towards human leukemic HL‐60 cells with an IC50 value of 19.9 μM.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Double Methylenecyclopentane Annulation of Succinimides: Easy Access to 3,7‐Dioxobicyclo[3.3.0]octane‐1,5‐dicarboximides
Authors: Camps Pelayo , Fernández José A. , Rull Jordi , Vázquez Santiago
Published: May 2009

N‐Alkylsuccinimides reacted with excess of LHMDS and 3‐chloro‐2‐(chloromethyl)‐1‐propene to give in medium yieldsN‐alkyl‐3,7‐dimethylenebicyclo[3.3.0]octane‐1,5‐dicarboximides, which were ozonized to the corresponding 3,7‐dioxobicyclo[3.3.0]octane‐1,5‐dicarboximides. When these alkylations were carried out by using LDA as the base, cis‐N‐alkyl‐4‐methylenecyclopentane‐1,2‐dicarboximides were mainly obtained, in spite of using excess of both base and alkylating agent.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Click Multivalent Homogeneous Neoglycoconjugates – Synthesis and Evaluation of Their Binding Affinities (Eur. J. Org. Chem. 15/2009)
Authors: Perez‐Balderas Francisco , Morales‐Sanfrutos Julia , Hernandez‐Mateo Fernando , Isac‐García Joaquín , Santoyo‐Gonzalez Francisco
Published: May 2009

The cover picture shows two copper(I) click‐based strategies for accessing multivalent neoglyconjugates by the coupling of complementary functionalized scaffolds and sugar derivatives. The methodology allows the easy preparation of structurally diverse homogeneous neoglycoconjugates from which the influence of the structural parameters in the binding affinities toward Concanavalin A could be evaluated. Details are discussed in the article by F. Santoyo‐Gonzalez et al. on page 2441ff.
Simultaneous Differential Pulse Voltammetric Determination of Sulfamethoxazole and Trimethoprim on a Boron‐Doped Diamond Electrode
Authors: Andrade Leonardo S. , Rocha‐Filho Romeu C. , Cass Quezia B. , Fatibello‐Filho Orlando
Published: May 2009

The performance of hydrogen‐ (HT) and oxygen‐terminated (OT) boron‐doped diamond (BDD) electrodes (electrochemically pretreated) on the simultaneous differential pulse voltammetric determination of sulfamethoxazole and trimethoprim in pharmaceutical products is presented. Under the optimum analytical experimental conditions, the HT‐BDD electrode presented two well‐defined oxidation peaks at 920 and 1100 mV vs. Ag/AgCl for sulfamethoxazole and trimethoprim, respectively. On the other hand, when the OT‐BDD electrode was used, the sulfamethoxazole oxidation current peak was decreased twenty fold. The calculated LOD values for sulfamethoxazole and trimethoprim using the HT‐BDD electrode were 3.65 μg L−1 and 3.92 μg L−1, respectively. The results obtained in the simultaneous determination of sulfamethoxazole and trimethoprim in three different commercial formulations were similar to those obtained using a standard HPLC method at 95% confidence level.
DNA Aptamers that Bind to PQQGDH as an Electrochemical Labeling Tool
Authors: Osawa Yuko , Takase Madoka , Sode Koji , Ikebukuro Kazunori
Published: May 2009

We screened DNA aptamers that bind to pyrroquinoline quinone glucose dehydrogenase (PQQGDH) for the development of an electrochemical labeling tool. PQQGDH is an excellent enzyme for the signal amplification of biosensors. We focused on DNA aptamers as labeling agents and tried to select those DNA aptamers that bind to PQQGDH without affecting its enzymatic activity. After 7 rounds of screening, one aptamer was obtained: ‘PGa4’. It bound to PQQGDH with specificity and showed no effect on the glucose dehydrogenase (GDH) activity. Moreover, beads labeled with PQQGDH via PGa4 generated an electrical current upon glucose addition. Therefore, we believe that the PGa4 aptamer against PQQGDH may become a powerful labeling tool for electrochemical biosensors.
Electrochemistry and Adsorptive Stripping Voltammetric Determination of Amoxicillin on a Multiwalled Carbon Nanotubes Modified Glassy Carbon Electrode
Authors: Rezaei Behzad , Damiri Sajjad
Published: May 2009

The study of electrochemical behavior of amoxicillin (AMX), a β‐lactam antibiotic, is described on a multiwalled carbon nanotubes (MWCNTs) modified electrode by electrochemical impedance spectroscopy (EIS) and adsorptive stripping voltammetry for sensitive determination of AMX in pharmaceutical and human urine samples within a wide pH range from 2.0 to 10.0. Also, studies by Fe2O3 nanoparticles modified carbon paste electrode show that iron oxide impurities in the MWCNTs are not active sites for sensing of amoxicillin. Under optimized conditions, the oxidation peak has two linear dynamic ranges of 0.6–8.0 and 10.0–80.0 μM with a detection limit of 0.2 μM and a precision of <4%.
Maximum penetration level of distributed generation with safety criteria
Authors: Van Thong Vu , Belmans Ronnie
Published: May 2009

Many recent blackouts might raise a concern on how the introduction of distributed generation (DG) (fromrenewableor non‐renewable energy resources) into the network influences its secure operation in terms of dynamic performance. The anti‐islanding criteria of DG may harm the secure operation of the power system. In this paper, the maximum penetration level of DG is determined using dynamic studies. Tested systems are applied to verify a proposed methodology. The results show that the protection settings have an influence the maximum penetration of DG and the system secure operation. Copyright © 2009 John Wiley & Sons, Ltd.
Understanding the partial discharge activity of conducting particles in GIS under DC voltages using the UHF technique
Authors: Sarathi R. , Umamaheswari R.
Published: May 2009

The major cause of failure of DC‐GIS is due to presence of foreign particles causing partial discharges in the insulation structure. The particle movement in gas insulated system (GIS) radiates electromagnetic waves and the bandwidth of the signal lies in the range 1–2 GHz. Increase in applied DC voltage/pressure has not altered the frequency content of the ultra high frequency (UHF) signal generated due to partial discharge formed by particle movement. The UHF sensor could recognize the breakdown of sulfur‐hexa‐fluoride (SF6) gas under DC and Lightning impulse voltages and the frequency content of the signal captured by the UHF sensor lies up to 500 MHz. Mounting UHF sensor in GIS could allow one to classify internal partial discharges from breakdown, at the time of testing/during operation. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of fermentation on free and bound volatile compounds of orange juice
Authors: Fan Gang , Lu Wei , Yao Xiaolin , Zhang Yun , Wang Kexing , Pan Siyi
Published: May 2009

Aroma is one of the most important attributes of orange wine quality. The volatile compounds in orange wine mainly derive from oranges, yeast fermentation and compounds released from odourless glycosidic precursors present in the orange. In this study, free volatile compounds in orange juice and wine made from Citrus sinensis (L). Osbeck cv. Washington Sanguine were analysed by SPME‐GC–MS. Bound fractions were isolated and extracted with methanol and Amberlite XAD‐2 resin and then hydrolysed by almond β‐glucosidase. Totals of 31 and 19 free volatiles were identified in orange juice and wines, respectively. Terpenes were the most abundant compounds in orange juice, while esters were quantitatively the dominant group in orange wine and most of them were compounds newly formed during fermentation, such as isoamyl acetate, ethyl hexanoate, ethyl benzoate, diethyl succinate, ethyl decanoate and ethyl laurate. In total, 11 and three released bound volatiles were found in orange juice and wine, respectively, and most of them were not found in free form. Only ethyl 3‐hydroxyhexanoate and cis‐carveol were found present in both the free and bound forms of orange juice. Copyright © 2009 John Wiley & Sons, Ltd.
The effect of aging on the inhibitory function in middle‐aged subjects: a functional MRI study coupled with a color‐matched Stroop task
Authors: Mathis Alexandre , Schunck Thérèse , Erb Gilles , Namer Izzie Jacques , Luthringer Rémy
Published: May 2009

Objective

The effects of aging on the inhibitory function are largely described in the neuroimaging literature but little data is available on the beginning of this age‐related impairment.

Methods

In this study, we described the cortical activation of middle‐aged (mean age ± standard error to the mean, 51.7 ± 3.1) subjects compared to young (26.8 ± 3.4) and elderly subjects (62.8 ± 3) while they performed a color‐matched Stroop task during functional magnetic resonance imaging. The task consisted in identifying the printing color of a word regardless of its meaning. Three conditions were defined depending on the meaning of this word; neutral (no meaning), congruent (color name matching the printing color), incongruent (color name mismatching the printing color), with interference effect in the latter.

Results

Middle‐aged subjects were as slow as elderly compared to young for all conditions and both were less accurate than young subjects during interference condition. Elderly showed an activity more bilateral and greater in the parietal lobule, the dorsolateral and ventrolateral prefrontal cortex (DLPFC, VLPFC) during both congruent and incongruent conditions compared to young. Middle‐aged showed an intermediary level of activity between those of elderly and young subjects in the left DLPFC, VLPFC and parietal lobule only during incongruent condition.

Conclusion

These results suggested that the age‐related impairment of the inhibitory process could already occur around the age of 50 years and consist in an increase of the activity in the left prefrontal and parietal cortex before increasing more and becoming bilateral around the age of 60 years. Copyright © 2009 John Wiley & Sons, Ltd.
The symptomatology of post‐stroke depression: comparison of stroke and myocardial infarction patients
Authors: Bour A. , Rasquin S. , Aben I. , Strik J. , Boreas A. , Crijns H. , Limburg M. , Verhey F.
Published: May 2009

Background

Depression is a frequent problem in stroke patients but, all too often, the problem goes unrecognized. How depression‐like symptoms in post‐stroke depression (PSD) should be interpreted is still subject to debate. If PSD has a distinct symptom profile of depression accompanying other chronic vascular somatic conditions then this could imply that PSD is a specific disease entity.

Objective

To study whether depressed stroke patients exhibit other signs and symptoms than patients suffering from depression after myocardial infarction (MI).

Methods

Depressive signs and symptoms were measured using the Hospital Anxiety and Depression Scale and the 17‐item Hamilton Depression Rating Scale. The results of 190 stroke patients were compared with the results of 198 MI patients every 3 months during the first year after the event.

Results

Depressed stroke patients exhibited more loss of interest, psychomotor retardation, and gastro‐intestinal complaints as compared to depressed MI patients. However, in multivariate analyses including both depressed and non‐depressed stroke and MI patients, no specific symptom profile was found to differentiate between the two depressive syndromes by looking at the modifying effect of stroke vs MI on the occurrence of specific symptoms in depression.

Conclusion

Although in their clinical presentation, depressed stroke patients exhibit a symptom profile different from depressed MI patients, this is not due to differences in the depressive syndrome in these two patient groups but it reflects differences between stroke and MI patients in general. Copyright © 2009 John Wiley & Sons, Ltd.