bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: 1,2,4‐Triazole Synthesis via Amidrazones.
Authors: El Kaim Laurent , Gizzi Marion , Grimaud Laurence
Published: November 2010

The optimized one‐pot two‐step procedure allows the preparation of various 1,2,4‐triazoles from aromatic amides and phenylhydrazine via an amidrazone intermediate [cf (III)].
ChemInform Abstract: Synthesis of Substituted 3‐Chloro‐1‐(3‐ (trifluoromethyl)‐5‐methoxy‐4H‐1,2,4‐triazol‐4‐yl) ‐4‐phenylazetidin‐2‐ones.
Authors: Paliwal Rakesh , Sekhar K. Chandra , Taneja Amit , Mishra S. K.
Published: November 2010

Most of the title compounds (VII) exhibit moderate antibacterial activities, but only compound (VIIc) possesses moderate antifungal activities.
ChemInform Abstract: Skeletal Diversity via Cationic Rearrangements of Substituted Dihydropyrans.
Authors: Medeiros Matthew R. , Narayan Radha S. , McDougal Nolan T. , Schaus Scott E. , Porco John A. Jr.
Published: November 2010

Benzyloxy‐substituted dihydropyrans undergo acid‐catalyzed rearrangement to provide highly functionalized isochroman scaffolds.
ChemInform Abstract: Synthesis of Substituted 4‐Pyridones and 4‐Aminopyridinium Salts via a One‐Pot Pyridine Synthesis.
Authors: Andersson Hans , Das Sajal , Gustafsson Magnus , Olsson Roger , Almqvist Frederik
Published: November 2010

Addition of Grignard reagents to N‐oxides (I) provides pyridines (III) which are further converted into pyridones (V) and 4‐aminopyridinium salts (VI) upon treatment with NaOH and NH3, respectively.
ChemInform Abstract: Tandem Asymmetric Michael Reaction—Intramolecular Michael Addition. An Easy Entry to Chiral Fluorinated 1,4‐Dihydropyridines.
Authors: Fustero Santos , Catalan Silvia , Sanchez‐Rosello Maria , Simon‐Fuentes Antonio , del Pozo Carlos
Published: November 2010

The sequential treatment of optically active sulfoxide (I) with fluorinated nitriles and alkyl propiolates affords (sulfinylmethyl)dihydropyridines of type (IV) as single diastereomers in most cases.
ChemInform Abstract: One‐Pot Multicomponent Synthetic Route for New Quinolidinyl 2,4‐Thiazolidinediones (IV)
Authors: Mali Jyotirling R. , Bhosle Manisha R. , Mahalle Shital R. , Mane Ramrao A.
Published: November 2010

under microwave irradiation conditions using polyethylene glycol 400 as reaction medium and catalyst
ChemInform Abstract: Phosphomolybdic Acid (PMA)—SiO2 as a Heterogeneous Solid Acid Catalyst for the One‐Pot Synthesis of 2H‐Indazolo[1,2‐b]phthalazine‐triones.
Authors: Sabitha Gowravaram , Srinivas Chitti , Raghavendar Avula , Yada Jhillu Singh
Published: November 2010

Advantages of this method are its generality, short reaction time, easy workup, and ease of recovery and reuse of the catalyst.
ChemInform Abstract: Primary Amine Catalyzed Biginelli Reaction for the Enantioselective Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones.
Authors: Ding Derong , Zhao Cong‐Gui
Published: November 2010

Biginelli reaction of acetoacetate (I) with urea (II) and aromatic or aliphatic aldehydes proceeds smoothly in the presence of a quinidine‐derived primary amine (QDA) as organocatalyst to give the title dihydropyrimidinones (IV) and (VI), resp., in up to 78% optical purity.
ChemInform Abstract: Synthesis of 3‐Aryl‐4(3H)‐quinazolinones from Anthranilic Acid, Orthoesters, and Anilines Using Ce(CH3SO3)3·2H2O as Catalyst.
Authors: Wang Min , Song Zhi‐Guo , Zhang Ting‐Ting
Published: November 2010

The catalyst can be recovered and reused for three consecutive runs without significant loss of activity.
ChemInform Abstract: A Highly Efficient Method for the N‐Alkylation of Aminopyrazines: Synthesis of Hydrophilic Red Fluorescent Dyes.
Authors: Poreddy Amruta R. , Asmelash Bethel , Neumann William L. , Dorshow Richard B.
Published: November 2010

N,N′‐Dialkylated aminopyrazines of type (V) are easily prepared by reductive alkylation with different aldehydes.
ChemInform Abstract: One‐Pot Synthesis of Quinoxaline‐2‐carboxylate Derivatives Using Ionic Liquid as Reusable Reaction Media.
Authors: Mershram H. M. , Ramesh P. , Kumar G. Santosh , Reddy B. Chennakesava
Published: November 2010

The condensation of β‐halo‐ketoesters with 1,2‐diamines proceeds under mild conditions in [bmim]BF4.
ChemInform Abstract: Synthesis of New 5‐Acetyl(arylmethyliden)‐4‐thiazolidones.
Authors: Polovkovych Svyatoslav V. , Karkhut Andrii I. , Marintsova Natalia G. , Novikov Volodymyr P.
Published: November 2010

A variety of new compounds having a triazine and a 4‐thiazolidinone moiety [cf.
ChemInform Abstract: Synthesis and Structure of Dimethyl 3,6‐Diphenyl‐1,2‐dihydro‐1,2,4,5‐tetrazine‐1,2‐dicarboxylate.
Authors: Rao Guo‐Wu , Lu Xiao‐Jing , Hu Wei‐Xiao
Published: November 2010

In connection with the preparation of biologically interesting derivatives, treatment of substrate (I) with ester (II) is investigated.
ChemInform Abstract: Metallopeptides for Asymmetric Dirhodium Catalysis.
Authors: Sambasivan Ramya , Ball Zachary T.
Published: November 2010

Natural polypeptide ligands are used in the chiral rhodium‐catalyzed asymmetric insertion of diazoacetates into Si—H bonds.
ChemInform Abstract: A Green Procedure for the Regio‐ and Chemoselective Hydrophosphonylation of Unsaturated Systems Using CaO under Solventless Conditions.
Authors: Martinez‐Castro Elisa , Lopez Oscar , Maya Ines , Fernandez‐Bolanos Jose G. , Petrini Marino
Published: November 2010

Diethyl phosphite (II) and diphenylphosphine add to a series of unsaturated derivatives using CaO as basic promoter under solventless conditions.
ChemInform Abstract: Chiral N,N′‐Dioxide‐Yb(III) Complexes Catalyzed Enantioselective Hydrophosphonylation of Aldehydes.
Authors: Chen Weiliang , Hui Yonghai , Zhou Xin , Jiang Jun , Cai Yunfei , Liu Xiaohua , Lin Lili , Feng Xiaoming
Published: November 2010

The addition of small amounts of pyridine to the reaction mixture promotes both reactivity and enantioselectivity.
ChemInform Abstract: Solvent‐ and Catalyst‐Free Reaction of (Aminomethyl)phosphonates with Epoxides: Synthesis of Novel {[(2‐Hydroxyethyl)amino]methyl}phosphonates.
Authors: Kaboudin Babak , Sorbiun Mina
Published: November 2010

Ring opening of epoxides (II) with (aminomethyl)phosphonates (I) occurs at the sterically less hindered position on the epoxide to afford the title compounds (III) in moderate to good yields.
ChemInform Abstract: Organic Dyes with Remarkably High Absorptivity; All Solid‐State Dye Sensitized Solar Cell and Role of Fluorine Substitution.
Authors: Chou Pi‐Tai , et al. et al.
Published: November 2010

New organic dyes are synthesized, among which compound (IIb) having a fluorine substitution attains excellent all solid‐state DSSC performance.
ChemInform Abstract: Total Synthesis of Pulverolide: Revision of Its Structure.
Authors: Yang Wanqiu , Liu Jikai , Zhang Hongbin
Published: November 2010

Total synthesis of the proposed structure (I) results in mismatch of spectroscopic data.
ChemInform Abstract: Ansellone A (I), a Sesterterpenoid Isolated from the Nudibranch Cadlina luteromarginata and the Sponge Phorbas sp., Activates the cAMP Signaling Pathway.
Authors: Daoust Julie , Fontana Angelo , Merchant Catherine E. , de Voogd Nicole J. , Patrick Brian O. , Kieffer Timothy J. , Andersen Raymond J.
Published: November 2010

In connection with the investigations, the absolute configuration of alotaketal A is revised to its enantiomeric structure (II).
ChemInform Abstract: H2SO4—SiO2: Highly Efficient and Novel Catalyst for the Ferrier‐Type Glycosylation.
Authors: Zhou Jia Fen , Chen Xuan , Wang Qing Bing , Zhang Bo , Zhang Li Yan , Yusulf Abdullah , Wang Zhong Fu , Zhang Jian Bo , Tang Jie
Published: November 2010

The reaction of glucal (I) with alcohols affords 2,3‐unsaturated glucopyranosides in high yield and α‐selectivity.
ChemInform Abstract: Synthesis of (.+‐.)‐Diospongin A: A Hetero‐Diels—Alder and C‐Glycosylation Approach.
Authors: More Jesse D.
Published: November 2010

The stereoselective synthesis of title compound (VII) is based on the Diels—Alder reaction catalyzed by ACC and a final anchimeric assistance‐controlled C‐glycosylation of the acetate (V).
ChemInform Abstract: Antimelanogenic Fatty Acid Derivatives from the Tuber‐Barks of Colocasia antiquorum var. esculenta.
Authors: Kim Ki Hyun , Moon Eunjung , Kim Sun Yeou , Lee Kang Ro
Published: November 2010

isolation and antimelanogenic activity of new monoglyceride (S)‐(I) and nine known fatty acid derivatives
ChemInform Abstract: The Essentials for the Control of Charge‐Orbital Ordering in Thin Films of Perovskite Manganites
Authors: Ogimoto Yasushi , Nakamura Masao , Harada Nobutaka , Ogawa Naoki , Miyano Kenjiro
Published: November 2010

Review: 44 refs.
ChemInform Abstract: Diverse Strategies for the Synthesis of the Indoline Scaffold.
Authors: Liu Dianyu , Zhao Guowei , Xiang Lan
Published: November 2010

Review: 57 refs.
ChemInform Abstract: Synthetic Studies Inspired by Vinigrol
Authors: Huters Alexander D. , Garg Neil K.
Published: November 2010

Review: 67 refs.
ChemInform Abstract: Chemistry and Heterocyclization of Carbohydrazides
Authors: Hassan Alaa A. , Shawky Ahmed M.
Published: November 2010

Review: 115 refs.
ChemInform Abstract: Multi‐Task Catalyst: Ruthenium Hydride Catalyzed Atom‐Economical Bond Forming Reactions
Authors: Fukuyama Takahide , Omura Sohei , Ryu Ilhyong
Published: November 2010

Review: ca. 50 refs.
ChemInform Abstract: Activation and Stabilization of Enzymes in Ionic Liquids.
Authors: Moniruzzaman Muhammad , Kamiya Noriho , Goto Masahiro
Published: November 2010

Review: about 200 refs.
ChemInform Abstract: Industrial Friedel—Crafts Chemistry
Authors: Macquarrie Duncan J.
Published: November 2010

Review: 76 refs.
ChemInform Abstract: Experimental Aspects of Solid State Circular Dichroism
Authors: Castiglioni Ettore , Biscarini Paolo , Abbate Sergio
Published: November 2010

Review: 129 refs.
A context‐aware semantic similarity model for ontology environments
Authors: Dong Hai , Hussain Farookh Khadeer , Chang Elizabeth
Published: November 2010

While many researchers have contributed to the field of semantic similarity models so far, we find that most of the models are designed for the semantic network environment. When applying the semantic similarity model within the semantic‐rich ontology environment, two issues are observed: (1) most of the models ignore the context of ontology concepts and (2) most of the models ignore the context of relations. Therefore, in this paper, we present a solution for the two issues, including a novel ontology conversion process and a context‐aware semantic similarity model, by considering the factors of both the context of concepts and relations, and the ontology structure. Furthermore, in order to evaluate this model, we compare its performance with that of several existing models' performance in a large‐scale knowledge base, and the evaluation result preliminarily proves the technical advantage of our model in ontology environments. Conclusions and future works are described in the final section. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and Photocatalytic Activity of Perovskite Niobium Oxynitrides with Wide Visible‐Light Absorption Bands
Authors: Siritanaratkul Bhavin , Maeda Kazuhiko , Hisatomi Takashi , Domen Kazunari
Published: November 2010

Photocatalytic activities of perovskite‐type niobium oxynitrides (CaNbO2N, SrNbO2N, BaNbO2N, and LaNbON2) were examined for hydrogen and oxygen evolution from water under visible‐light irradiation. These niobium oxynitrides were prepared by heating the corresponding oxide precursors, which were synthesized using the polymerized complex method, for 15 h under a flow of ammonia. They possess visible‐light absorption bands between 600–750 nm, depending on the A‐site cations in the structures. The oxynitride CaNbO2N, was found to be active for hydrogen and oxygen evolution from methanol and aqueous AgNO3, respectively, even under irradiation by light at long wavelengths (λ<560 nm). The nitridation temperature dependence of CaNbO2N was investigated and 1023 K was found to be the optimal temperature. At lower temperatures, the oxynitride phase is not adequately produced, whereas higher temperatures produce more reduced niobium species (e. g., Nb3+ and Nb4+), which can act as electron‐hole recombination centers, resulting in a decrease in activity.
Irxl1 mutant mice show reduced tendon differentiation and no patterning defects in musculoskeletal system development
Authors: Kimura Wataru , Machii Masashi , Xue XiaoDong , Sultana Nishat , Hikosaka Keisuke , Sharkar Mohammad T.K. , Uezato Tadayoshi , Matsuda Masashi , Koseki Haruhiko , Miura Naoyuki
Published: November 2010

Irxl1 (Iroquois‐related homeobox like‐1) is a newly identified three amino‐acid loop extension (TALE) homeobox gene, which is expressed in various mesoderm‐derived tissues, particularly in the progenitors of the musculoskeletal system. To analyze the roles of Irxl1 during embryonic development, we generated mice carrying a null allele of Irxl1. Mice homozygous for the targeted allele were viable, fertile, and showed reduced tendon differentiation. Skeletal morphology and skeletal muscle weight in Irxl1‐knockout mice appeared normal. Expression patterns of several marker genes for cartilage, tendon, and muscle progenitors in homozygous mutant embryos were unchanged. These results suggest that Irxl1 is required for the tendon differentiation but dispensable for the patterning of the musculoskeletal system in development. genesis, 2011. © 2010 Wiley‐Liss, Inc.
A communication aid and computer input system using only the human eye
Authors: Arai Kohei , Yajima Kenro
Published: November 2010

A communication aid using only the human eye is proposed. A set of candidate characters is displayed on a relatively small computer screen and a light head‐mounted display (HMD) that is attached to glasses worn by the user. When the user looks at a candidate character with the left eye, an image of the right eye is taken with a small and light web camera that also is mounted on the glasses. The proposed system can select one character out of 81 characters, with two layers of 9 by 9 character candidate screen images. There is also another selection image including control keys and frequently used sentences. By using image matching between a previously acquired template image for each candidate character and the currently acquired image, the proposed system can determine which of the candidate characters has been selected. By the combined use of blinking and fixed gaze, the proposed system can determine the user‐selected key among the candidates. The blink detection method employs a morphologic filter to avoid erroneous pupil detection due to eyebrows and shadows. Thus the user can input sentences. The user can also edit the sentences, which are then read by a text‐to‐speech (TTS) software tool. Thus the system helps handicapped and disabled persons without voice to communicate with others, because the only function required for conversation is the human eye. In addition, the proposed system can be used as an input system for wearable computing systems. Test results obtained with 6 nondisabled persons showed that the proposed system worked at an acceptable speed of about 1.5 second per character. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(12): 1–9, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10317
Effect of Temperature on the Catalytic Ability of Electrochemically Active Biofilm as Anode Catalyst in Microbial Fuel Cells
Authors: Liu Ying , Climent Victor , Berná Antonio , Feliu Juan Miguel
Published: November 2010

In this study we report the effect of temperature on the catalytic ability of an electrochemically active biofilm based on mixed‐culture to oxidize acetate and found the optimum temperature showing maximal catalytic activity and power output. Electrochemical characterization of biofilm and power output and internal resistance of microbial fuel cell (MFC) have been investigated at different temperatures. When temperature increased from 30 to 45 °C the catalytic ability of biofilms to oxidize acetate increased following the Arrhenius law with apparent activation energy of 44.85 kJ/mol. At temperatures higher than 48 °C, however, the bioelectrocatalytic current decreased. At 53 °C the bacterial metabolism was in inactivation. The optimum working temperature of the biofilm was 45 °C, producing current of 1339 µA cm−2. This current was almost three times higher than 527 µA cm−2 at 30 °C. The MFC performance at different temperatures showed consistent temperature dependence to that of a semi‐batch cell, which implies that anode catalytic ability in MFC is the main limit factor for increasing power output. A maximum power output of 1065 mW m−2 was also observed at 45 °C and it was 1.5 times higher than 764 mW m−2 at 30 °C. The increased MFC performance from 30 °C to 45 °C is lower in comparison with about three times higher increase in semi‐batch cells. This could be due to other factors such as proton migration rate in membrane of MFC, which can be seen from that the internal resistance value of 121.5 Ω in the MFC at 45 °C was only slightly lower than 177.6 Ω at 30 °C. Also, some other factors such as cell configuration which would limit the power output and can be further optimized. This work contributes to the study of influence from temperature on anodic electrochemically active biofilm activity and their subsequent influence on MFC performance and reports the optimal temperature for biofilm activity based on mixed‐culture.
Viable tumor in postchemoradiation neck dissection specimens as an indicator of poor outcome
Authors: Ganly Ian , Bocker Jennifer , Carlson Diane L. , D'Arpa Salvatore , Coleman Maria , Lee Nancy , Pfister David G. , Shah Jatin P. , Patel Snehal G.
Published: November 2010

Background

The objective of this study was to determine the prognostic significance of viable tumor in postchemoradiation neck dissection specimens in patients with squamous cell carcinoma of the laryngopharynx.

Methods

Retrospective analysis identified 181 patients treated with primary concurrent chemoradiation for carcinoma of the laryngopharynx at Memorial Sloan‐Kettering Cancer Center between the years 1995 and 2005. Of these, 56 patients had a comprehensive neck dissection either as a planned or salvage procedure. Neck dissection specimens were analyzed by a single pathologist for the presence of viable tumor. The presence of viable tumor was correlated to the timing of neck dissection after chemoradiation and to tumor response. Overall survival (OS), disease‐specific survival (DSS), and recurrence‐free survival (RFS) were determined by the Kaplan–Meier method, and correlation to tumor viability was determined with the log‐rank test.

Results

Nineteen (33%) patients had viable tumor in their neck dissection specimens. Viable tumor was higher in patients who had a less‐than‐complete response to chemoradiation compared with those who had a complete response (42% vs 25%, p = .1). There was no correlation to timing of neck dissection. The 5‐year OS, DSS, and RFS were significantly lower in patients who had viable tumor in their neck dissection specimens (OS 49% vs 93%, p = .0005; DSS 56% versus 93%, p = .003; RFS 40% vs 75%, p = .004).

Conclusions

Patients with viable tumor in postchemoradiation neck dissection specimens had a poorer outcome compared with patients with no viable tumor. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Chitosan‐poly(ε‐caprolactone)‐poly(ethylene glycol) graft copolymers: Synthesis, self‐assembly, and drug release behavior
Authors: Chen Chen , Cai Guoqiang , Zhang Haiwen , Jiang Hongliang , Wang Liqun
Published: November 2010

Biodegradable tri‐component graft copolymers, chitosan‐poly(ε‐caprolactone)‐poly(ethylene glycol) (CPP), were synthesized via a mild route, using sodium dodecyl sulfate‐chitosan complex (SCC) as a precursor. Both PCL and PEG could be conveniently conjugated to the hydroxyl sites of chitosan without the need of tedious chemical protection/deprotection processes, thereby leaving the amino groups of chitosan intact. The self‐assembly and release behavior of the copolymer micelles were investigated. Paclitaxel and rutin were used as model drugs. Spherical micelles could be formed through self‐assembly of CPP in aqueous media. The micelle diameter increased with PEGylation degree and ranged from 30 to 45 nm. The incorporation of drugs into the micelles significantly raised the micelle diameter and diversified the micelle morphologies. The micelles were further subjected to glutaraldehyde treatment to prolong the release of the incorporated drugs. It was found that the crosslinking process shrunk the drug‐loaded micelles. In addition, the micelles were endowed with self‐luminescent properties after crosslinked with glutaraldehyde. By increasing crosslinking density, the release duration of the model drugs could be prolonged. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Carbon dioxide flux in the centre of Łódź, Poland—analysis of a 2‐year eddy covariance measurement data set
Authors: Pawlak Włodzimierz , Fortuniak Krzysztof , Siedlecki Mariusz
Published: November 2010

Continuous measurements of carbon dioxide turbulent flux F carried out with the eddy covariance method have been made in Łódź since F July 2006. The measurement point (Lipowa Station) is located in the west part of the densely built‐up city centre, where artificial surfaces clearly prevail over natural terrain. The measurement system includes a Kipp and Zonen's (Delft, Holland) CNR1 net radiometer, RMYoung (Traverse City, Michigamn, USA) 81000 sonic anemometer and Li‐cor (Lincoln, Nebraska, USA) 7500 open path H2O/CO2 infrared gas analyser. Sensors are installed on the high tower 20 m above the roof of the building and 37 m above the ground, so the measurement height exceeded the urban canopy layer more than twice. The diurnal and annual variability of carbon dioxide flux for the period July 2006 to August 2008 is analysed in the article. The results show the characteristic features in diurnal and annual courses of F. Independently from the season, positive (upward) fluxes of the order of 0–15 µmol m−2 s−1 prevail in the data. During the cold season, an increase in turbulent CO2 exchange is observed (F quite often exceeded 30 µmol m−2 s−1). This can be attributed to anthropogenic CO2 emissions, which are particularly strong in winter due to, among other things, mineral fuel combustion during domestic heating. The average monthly fluxes are positive in all seasons, which means that emission of CO2 in the surroundings of the measurement point prevails over its uptake. Apart from the season, the maximum flux occurred during the day and the minimum during the second part of the night. Wintertime monthly averaged fluxes are much higher than summertime ones. The observed increase in CO2 exchange during weekdays in comparison with weekends can be caused by the weekly rhythm of traffic in the surroundings of Lipowa Station. Copyright © 2010 Royal Meteorological Society
Do satisfied customers bad‐mouth innovative products?
Authors: Parthasarathy Madhavan , Forlani David
Published: November 2010

For many years marketing academics have recommended, and practitioners have implemented, organization‐wide programs that measure customers' levels of satisfaction with a firm's offerings because it is believed that satisfied customers are both more likely to continue using a previously adopted product and less likely to engage in negative word‐of‐mouth communication. Given the ubiquity of product‐review forums resulting from today's increasing levels of e‐commerce, this paper pairs cause constructs from the diffusion literature with effect constructs from the satisfaction and services literatures to reconsider that perspective. Specifically, it examines the relationships bet‐ween six perceived innovation attributes known to influence a new product's diffusion process and two post‐adoption behaviors, satisfaction and negative word‐of‐mouth communication. The results quash previous assumptions that satisfaction mediates negative word‐of‐mouth communication and reveal that satisfied customers do speak ill of previously adopted products. Implications for both theory and practice are also presented. © 2010 Wiley Periodicals, Inc.
Mn‐bicine: A low affinity chelate for manganese ion enhanced MRI
Authors: Seo Yoshiteru , Satoh Keitaro , Watanabe Kazuto , Morita Hironobu , Takamata Akira , Ogino Takashi , Murakami Masataka
Published: November 2010

The toxicity of free Mn2+ is a bottleneck for the in vivo application of manganese ion enhanced MRI. To reduce free Mn2+ concentration ([Mn2+]), a low affinity chelate reagent: N,N‐bis(2‐hydroxyethyl)glycine (bicine) was used. Considering the conditional association constant of Mn‐bicine at pH 7.4 (102.9 M−1), (i) a 100 mM Mn‐bicine solution should contain about 10 mM of free manganese ion, but (ii) free manganese will make up 3/4 of the final plasma concentration (0.5 mM) with an intravenous infusion of 100 mM Mn‐bicine. The T1 relaxivity of Mn‐bicine in a 5 mM Mn‐bicine solution was estimated as 5 mM−1 sec−1 at 24°C, 7 T in a pH range of 6.8–7.5. Mn‐bicine demonstrated a tendency for better contractility when employed with an isolated perfused frog heart, compared with MnCl2. A venous infusion of 100 mM Mn‐bicine (8.3 μmol kg−1 min−1) showed a minimal decrease and maintained a constant heart rate level and arterial pressure in rats, while rats infused with 100 mM of MnCl2 showed a significant suppression of the hemodynamic functions. Thus, Mn‐bicine appears to be a better choice for maintaining the vital conditions of experimental animals, and may improve the reproducibility of manganese ion enhanced MRI. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Picture change error correction of radon atom electron density
Authors: Bučinský Lukáš , Biskupič Stanislav , Jayatilaka Dylan
Published: November 2010

The importance of the picture change error (PCE) correction in the quasirelativistic electron density of radon atom is presented. PCE correction is considered for the infinite order two-component (IOTC) and second order Douglas–Kroll–Hess (DKH2) wave functions. Implementation details of PCE correction of electron density are outlined. The result section presents the radial distributions of electron density ρ(r) and the 4πr2ρ(r) function of the radon atom in the nuclear region. The PCE corrected and contaminated DKH2, IOTC electron densities are presented and compared with the Dirac–Coulomb Hamiltonian and nonrelativistic electron densities. Besides, some additional effects in electron density and SCF energy are considered, such as spin-orbit coupling, the inclusion of the Gaunt term, and the finite nucleus model effects. The effects of p̂2Vp̂2 and p̂2ρ̂(r)p̂2 analytic integral classes within IOTC Hamiltonian and PCE correction of IOTC electron density are considered.
A transition state view on reactive scattering: Initial state-selected reaction probabilities for the H+CH4→H2+CH3 reaction studied in full dimensionality
Authors: Schiffel Gerd , Manthe Uwe
Published: November 2010

Initial state-selected reaction probabilities for the H+CH4→H2+CH3 reaction are computed for vanishing total angular momentum by full-dimensional calculations employing the multiconfigurational time-dependent Hartree approach. An ensemble of wave packets completely describing reactivity for total energies up to 0.58 eV is constructed in the transition state region by diagonalization of the thermal flux operator. These wave packets are then propagated into the reactant asymptotic region to obtain the initial state-selected reaction probabilities. Reaction probabilities for reactants in all rotational states of the vibrational 1A1, 1F2, and 1E levels of methane are presented. Vibrational excitation is found to decrease reactivity when reaction probabilities at equivalent total energies are compared but to increase reaction probabilities when the comparison is done at the basis of equivalent collision energies. Only a fraction of the initial vibrational energy can be utilized to promote the reaction. The effect of rotational excitation on the reactivity differs depending on the initial vibrational state of methane. For the 1A1 and 1F2 vibrational states of methane, rotational excitation decreases the reaction probability even when comparing reaction probabilities at equivalent collision energies. In contrast, rotational energy is even more efficient than translational energy in increasing the reaction probability when the reaction starts from the 1E vibrational state of methane. All findings can be explained employing a transition state based interpretation of the reaction process.
Surface layer protein characterization by small angle x-ray scattering and a fractal mean force concept: From protein structure to nanodisk assemblies
Authors: Horejs Christine , Pum Dietmar , Sleytr Uwe B. , Peterlik Herwig , Jungbauer Alois , Tscheliessnig Rupert
Published: November 2010

Surface layers (S-layers) are the most commonly observed cell surface structure of prokaryotic organisms. They are made up of proteins that spontaneously self-assemble into functional crystalline lattices in solution, on various solid surfaces, and interfaces. While classical experimental techniques failed to recover a complete structural model of an unmodified S-layer protein, small angle x-ray scattering (SAXS) provides an opportunity to study the structure of S-layer monomers in solution and of self-assembled two-dimensional sheets. For the protein under investigation we recently suggested an atomistic structural model by the use of molecular dynamics simulations. This structural model is now refined on the basis of SAXS data together with a fractal assembly approach. Here we show that a nondiluted critical system of proteins, which crystallize into monomolecular structures, might be analyzed by SAXS if protein-protein interactions are taken into account by relating a fractal local density distribution to a fractal local mean potential, which has to fulfill the Poisson equation. The present work demonstrates an important step into the elucidation of the structure of S-layers and offers a tool to analyze the structure of self-assembling systems in solution by means of SAXS and computer simulations.
Drag reduction by microbubbles in a turbulent boundary layer
Authors: Jacob Boris , Olivieri Angelo , Miozzi Massimo , Campana Emilio F. , Piva Renzo
Published: November 2010

An experimental characterization of the turbulent boundary layer over a flat plate in the presence of small amounts of microbubbles is performed. The average diameter of the injected bubbles is comparable with the local Kolmogorov lengthscale, and the bulk void fraction C¯ is approximately 0.1%. The velocity field of the liquid phase, as well as the bubble characteristics, is acquired by optical techniques. Even at the small void fraction typical of this investigation, the interaction between microbubbles and turbulence leads to significant modifications of the underlying flow field. In accordance with previous investigations, the main global effect consists in a reduction of the magnitude of the viscous drag. This has been checked with preliminary tests conducted in a towing tank, as well as by inferring the wall stress from the boundary layer velocity profile measured in a laboratory facility at the same conditions. Here, the local wall stress is found to drop by approximately 25%. An analysis of the turbulent statistics shows that the reduction in drag is accompanied by a substantial reduction of the momentum flux throughout most of the inner region and by a decrease of the characteristic dimension of the turbulent scales involved in the production of kinetic energy. The distribution of turbulent kinetic energy among different scales is found to be substantially altered in the two flows. In particular, an enhancement of the energy content at smaller scales is observed in the bubbly case. These effects are discussed in relation with the decrease of the coherence of near-wall flow structures induced by the bubble forcing.
The superluminal propagation in an organic nonlinear optical glass at room temperature
Authors: Ouyang Qiu-Yun , Zhang Yun-Dong , Tian He , Liu Da-Jun , Yuan Ping , Song Ying-Lin
Published: November 2010

We investigated the light propagation in an organic glass with phthalocyanine gallium (GaPc) dispersed in polymethyl methacrylate (PMMA) fabricated by injection molding. The GaPc/PMMA organic glass is a reverse saturation absorption medium. We observed the superluminal propagation in this organic glass by using the technique of coherent population oscillations at room temperature. The largest time advancement is 2.21 ms and the corresponding group velocity is −0.90 m/s at the wavelength of 532 nm and with the input power of 89 mW. The density matrix theory with four-level model was used to analyze the experimental data. The theoretical simulations showed that the time advancement not only depends on the modulation frequency but also on the lifetime of the first triplet-state of the GaPc. We compared the time advancements between the GaPc/PMMA organic glass and the C60/toluene solution. Although the value of the former is smaller, it is more suitable for practical applications such as optical information processing than the latter.
Single-crystal elastic properties of (Cs,Na)AlSi2O6⋅H2O pollucite: A zeolite with potential use for long-term storage of Cs radioisotopes
Authors: Sanchez-Valle Carmen , Chio Chi-Hong , Gatta G. Diego
Published: November 2010

The single-crystal and aggregate elastic properties of the zeolite pollucite (Cs,Na)AlSi2O6⋅H2O, a potential host for Cs radionucleides in geological repositories, have been determined by Brillouin scattering spectroscopy at ambient conditions. The three nonzero individual elastic constants of cubic pollucite are: C11=105.0(1.3) GPa, C44=27.0(3) GPa, and C12=25.7(6) GPa. The Voigt–Reuss–Hill average of the aggregate bulk, shear modulus, Young's modulus and Poisson’s ratio are KS=52.2(1.0) GPa, G=31.5(7) GPa, E=78.6(1.0) GPa, and ν=0.248(4), respectively. The bulk modulus of pollucite is 12.7% lower than that of the all-Na isotypic mineral analcime NaAlSi2O6⋅H2O whereas the shear moduli G are identical within mutual uncertainties. The higher compressibility of pollucite results from the weaker Cs–O bonds compared to Na–O bonds, suggesting strong control of the nature and configuration of the extraframework content on the behavior of the structure. The elastic properties of pollucite reported here will help in the prediction of its behavior as a geological barrier and in the modeling of the short-term and long-term safety of the Cs-repositories.
Nonconventional magnetism in pristine and alkali doped In2O3: Density functional study
Authors: Guan L. X. , Tao J. G. , Huan C. H. A. , Kuo J. L. , Wang L.
Published: November 2010

Using In2O3 as a host matrix, extensive calculations based on density functional theory have been carried out to understand the electronic and magnetic properties of native defects, alkali and alkaline-earth metal substitutions as disputed in recent theoretical and experimental studies. Our calculations show that the magnetism in undoped In2O3 is originated from In vacancies (VIn) instead of O vacancies. The ferromagnetic (FM) coupling between the moments introduced by VIn is found strong enough to achieve room temperature ferromagnetism. Moreover, FM coupling is also strongly favored in alkali metal doping cases with negative formation energy. For all XIn (XIn=VIn, LiIn, NaIn, and KIn) doped In2O3, the induced magnetic moments are mainly localized on the first shell of O atoms around XIn sites. The FM coupling between the moments induced by XIn defects is activated by intra- and intercorrelation of the XIn–6ONN complexes. A XIn–ONN–InNN–ONN–XIn chain is required to mediate the long-range FM coupling. However, in cases of Mg or Ca doped In2O3, the ground state is nonmagnetic.
Unexpected transverse velocity component of Xe+ ions near the exit plane of a Hall thruster
Authors: Bourgeois G. , Mazouffre S. , Sadeghi N.
Published: November 2010

The velocity component of singly charged xenon ions in a plane perpendicular to the thrust axis of the 1 kW-class PPS100-ML Hall effect thruster is deduced from laser induced fluorescence measurements on the 5d 2F7/2→6p 2D5/20 electronic transition at 834.72 nm. Measurements are carried out at several locations in the near field of the channel exhaust. Thruster operating parameters, such as magnetic field strength, discharge voltage, and xenon mass flow rate, are varied over a wide range. The initial aim of this work was to measure the azimuthal velocity of the ions due to their weak magnetic deflection. Surprisingly, experimental results cannot be explained by the one and only Lorentz force acting on Xe+ ions. A realistic picture of the ion trajectory in the E×B drift plane is obtained when adding a velocity component directed toward the external cathode.
Low resistance, high dynamic range reconfigurable phase change switch for radio frequency applications
Authors: Chua E. K. , Shi L. P. , Zhao R. , Lim K. G. , Chong T. C. , Schlesinger T. E. , Bain J. A.
Published: November 2010

A GeTe reconfigurable phase change switch for radio frequency applications is presented. Low ON state resistance (180 Ω) and large dynamic range (7×103 X) were achieved through low resistance electrode design and high current. A partial crystallization and partial reamorphization model is proposed to explain the differences between the measured and calculated device ON (set) and OFF (reset) state resistances, respectively. The dependency between ON state resistance and reset current was estimated using a first order thermal design in steady state which suggests lower reset current by choosing materials of lower melting temperature and structures with better thermal isolation.
Magnetocurrent of ballistically injected electrons in insulating silicon
Authors: Jang Hyuk-Jae , Appelbaum Ian
Published: November 2010

By using ballistic hot-electron injection to achieve lateral conduction through an otherwise fully insulating undoped silicon channel, we are able to study magnetic field suppression of charge transport in a regime normally excluded in Ohmic magnetoresistance measurements. Exceptionally large magnetocurrent changes of >16 000% at 45 K in magnetic fields of ≈2 T are observed, with differential reduction of over 6.2 T−1. Temperature-, electrostatic back-gate-, and magnetic field angle-dependence are presented. This phenomenon is attributed to strong space-charge effects in the dilute three-dimensional electron gas created by nonequilibrium injection.
Ultrasmooth microfabricated mirrors for quantum information
Authors: Biedermann G. W. , Benito F. M. , Fortier K. M. , Stick D. L. , Loyd T. K. , Schwindt P. D. D. , Nakakura C. Y. , Jarecki R. L. , Blain M. G.
Published: November 2010

In this paper, we realize a scalable micromirror suitable for atom chip based cavity quantum electrodynamics applications. A very low surface roughness of 2.2 Å rms on the silicon cavity mirrors is achieved using chemical dry etching along with plasma and oxidation smoothing. Our Fabry–Perot cavity comprised of these mirrors currently demonstrates the highest finesse, F=64 000, using microfabricated mirrors. We compute a single atom cooperativity for our cavities of more than 200, making them promising candidates for detecting individual atoms and for quantum information applications on a chip.
Archaeal-like chaperonins in bacteria
Authors: Techtmann Stephen M. , Robb Frank T.
Published: November 2010

Chaperonins (CPN) are ubiquitous oligomeric protein machines that mediate the ATP-dependent folding of polypeptide chains. These chaperones have not only been assigned stress response and normal housekeeping functions but also have a role in certain human disease states. A longstanding convention divides CPNs into two groups that share many conserved sequence motifs but differ in both structure and distribution. Group I complexes are the well known GroEL/ES heat-shock proteins in bacteria, that also occur in some species of mesophilic archaea and in the endosymbiotic organelles of eukaryotes. Group II CPNs are found only in the cytosol of archaea and eukaryotes. Here we report a third, divergent group of CPNs found in several species of bacteria. We propose to name these Group III CPNs because of their distant relatedness to both Group I and II CPNs as well as their unique genomic context, within the
hsp70
operon. The prototype Group III CPN,
Carboxydothermus hydrogenoformans
chaperonin (
Ch
-CPN), is able to refold denatured proteins in an ATP-dependent manner and is structurally similar to the Group II CPNs, forming a 16-mer with each subunit contributing to a flexible lid domain. The Group III CPN represent a divergent group of bacterial CPNs distinct from the GroEL/ES CPN found in all bacteria. The Group III lineage may represent an ancient horizontal gene transfer from an archaeon into an early Firmicute lineage. An analysis of their functional and structural characteristics may provide important insights into the early history of this ubiquitous family of proteins.
Catalytic activation of histone acetyltransferase Rtt109 by a histone chaperone
Authors: Kolonko Erin M. , Albaugh Brittany N. , Lindner Scott E. , Chen Yuanyuan , Satyshur Kenneth A. , Arnold Kevin M. , Kaufman Paul D. , Keck James L. , Denu John M.
Published: November 2010

Most histone acetyltransferases (HATs) function as multisubunit complexes in which accessory proteins regulate substrate specificity and catalytic efficiency. Rtt109 is a particularly interesting example of a HAT whose specificity and catalytic activity require association with either of two histone chaperones, Vps75 or Asf1. Here, we utilize biochemical, structural, and genetic analyses to provide the detailed molecular mechanism for activation of a HAT (Rtt109) by its activating subunit Vps75. The rate-determining step of the activated complex is the transfer of the acetyl group from acetyl CoA to the acceptor lysine residue. Vps75 stimulates catalysis (> 250-fold), not by contributing a catalytic base, but by stabilizing the catalytically active conformation of Rtt109. To provide structural insight into the functional complex, we produced a molecular model of Rtt109-Vps75 based on X-ray diffraction of crystals of the complex. This model reveals distinct negative electrostatic surfaces on an Rtt109 molecule that interface with complementary electropositive ends of a symmetrical Vps75 dimer. Rtt109 variants with interface point substitutions lack the ability to be fully activated by Vps75, and one such variant displayed impaired Vps75-dependent histone acetylation functions in yeast, yet these variants showed no adverse effect on Asf1-dependent Rtt109 activities in vitro and in vivo. Finally, we provide evidence for a molecular model in which a 1∶2 complex of Rtt109-Vps75 acetylates a heterodimer of H3-H4. The activation mechanism of Rtt109-Vps75 provides a valuable framework for understanding the molecular regulation of HATs within multisubunit complexes.
Match activities of top‐class female soccer assistant referees in relation to the offside line
Authors: Mallo Javier , Cala Antonio , González Frutos Pablo , Navarro Enrique
Published: November 2010

The aim of this study was to examine the match activities of top‐class female assistant referees (mean age 34.8 years, s=3.5; stature 1.64 m, s=0.05; weight 58.1 kg, s=7.4; body mass index 21.6 kg · m–2, s=2.4) in relation to the offside line. Computerized match analyses were performed on 14 top‐class assistant referees during 10 matches (a total of 20 observations) from the 2006 Fédération Internationale de Football Association (FIFA) under‐20 Women's World Championship held in Russia. In addition, the position of the second last defensive player of both teams was calculated throughout the matches to determine the distance from the assistant referee to the offside line. The total distance covered during a game was 5594 m (s=473), of which 27% was sideways movements (1492 m, s=135). High‐intensity activities (>13 km · h–1) accounted for 1999 m (s=371). Mean distance from the offside line during the entire match was 1.06 m (s=0.26). Total distance covered, high‐intensity activities, and distance from the offside line were not different (P>0.05) between the two halves of the game or consecutive 15‐min match periods. Our results show that: (1) the kinematic demands placed on top‐class female assistant referees are similar to those of top‐class male assistant refereeing except for the amount of high‐intensity activities, and (2) assistant referees were able to maintain the distance from the offside line during the match, which suggests an ability to keep up with the pace of the play throughout the match.
Hydrolysed Formula Is a Risk Factor for Vitamin K Deficiency in Infants With Unrecognised Cholestasis
Authors: van Hasselt PM , de Vries W , de Vries E , Kok K , Cranenburg ECM , de Koning TJ , Schurgers LJ , Verkade HJ , Houwen RHJ
Published: November 2010

Objectives:

Vitamin K deficiency (VKD) may cause life‐threatening haemorrhages, especially in breast‐fed infants with unrecognised cholestasis. Interestingly, hypoallergenic formulas appear overrepresented in reported cases of VKD bleeding (VKDB) in formula‐fed infants. We therefore assessed whether the risk of VKD in formula‐fed infants with cholestasis is associated with hypoallergenic formulas.

Patients and Methods:

Infants born in the Netherlands between January 1991 and December 2006 with cholestatic jaundice due to biliary atresia (BA) or to α‐1‐antitrypsin deficiency (A1ATD) were identified in the Netherlands Study Group for Biliary Atresia Registry and the A1ATD registry, respectively. The relative risk (RR) of VKDB in patients with BA or A1ATD was calculated for different formula types. The influence of prior or ongoing breast‐feeding on the RR of VKDB was also assessed.

Results:

A total of 179 infants with either BA (139) or A1ATD (40) were included. One hundred eighteen infants were formula fed; 8 presented with VKD. Six of these 8 infants (75%) received hypoallergenic formula (whey‐based hydrolysate in 4). One infant on whey‐based hydrolysed formula presented with VKDB. Risk factor analysis revealed that infants receiving hydrolysed, especially whey‐based, formula, had a strongly increased risk of VKD (RR 25.0 [6.4–97.2], P < 0.001)) compared with infants receiving regular formula. Prior or ongoing breast‐feeding was not significantly associated with VKD.

Conclusions:

Infants with cholestasis receiving (whey‐based) hydrolysed formula are at increased risk of developing VKD, compared with infants receiving regular formula. Because VKD may lead to serious haemorrhages, infants receiving whey‐based hydrolysed formulas may need additional vitamin K supplementation.