bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral and time‐frequency analyses of freeway traffic flow
Authors: Sun Lu
Published: April 2013

This paper uses spectral and time‐frequency analyses to treat three macroscopic traffic characteristics, namely, time mean speed, volume and occupancy as stochastic processes. Spectral and time‐frequency analyses are performed to characterize power spectral density (PSD), cross‐PSD, autocorrelation and cross‐correlation of these characteristics using TransGuide traffic data collected from four different freeways. It is found that low‐frequency components dominate the PSDs of speed, volume and occupancy at all times. The magnitude of PSDs decreases dramatically as frequency increases and remains almost at a constant level in high‐frequency regimes. A power law is found to exist, which describes the relationship between the frequency and the PSD of traffic characteristics. It is also found that speed can be properly modeled by a narrowband low‐pass stochastic process in a low‐frequency regime and by a nonzero mean white noise in a high‐frequency regime. Strong periodicities and synchronization are both shown in traffic flow. A variety of frequencies can be excited by congestion, and there is no dominant frequency found in stop‐and‐go traffic. Copyright © 2013 John Wiley & Sons, Ltd.
Determination of dobutamine hydrochloride by enzymatic catalytic spectrofluorimetry
Authors: Tian Feng‐Shou , Chen Ya‐Hong , Liang Hai‐Yan
Published: April 2013

A highly sensitive and simple spectrofluorimetric method for the determination of dobutamine hydrochloride based on its inhibitory effect on the hemoglobin‐catalyzed reaction of H2O2 and l‐tyrosine was developed. The relationship between the concentration of dobutamine hydrochloride and the fluorescence quenching (ΔF) of the system is linear under the optimal experimental conditions. The calibration graph is linear in the range 2.00 × 10‐7 to 3.00 × 10‐6 g/mL with a limit of detection of 4.83 × 10‐9 g/mL. This method can be used for the determination of dobutamine hydrochloride in its pharmaceutical formulations and in urine with satisfactory results. Copyright © 2013 John Wiley & Sons, Ltd.
Directed evolution of a highly efficient cellobiose utilizing pathway in an industrial Saccharomyces cerevisiae strain
Authors: Yuan Yongbo , Zhao Huimin
Published: April 2013

Balancing and increasing the flux through an engineered heterologous pathway in a target organism to achieve high yield and productivity remains an overwhelming challenge in metabolic engineering. Here we report a novel strategy combining directed evolution and promoter engineering for rapid and efficient multi‐gene pathway optimization. As proof of concept, this strategy was applied to optimize a cellobiose utilizing pathway in an industrial Saccharomyces cerevisiae strain for highly efficient cellulosic biofuels production. The resulting strain exhibited significantly higher cellobiose consumption rate (6.41‐fold) and ethanol productivity (6.36‐fold) compared to its parent strain. This study also showed that both the ratios and absolute values of the expression levels of the genes in the cellobiose utilizing pathway play an important role in cellobiose uptake, and β‐glucose is likely one of the key factors affecting cellobiose metabolism. Biotechnol. Biotechnol. Bioeng. 2013;110: 2874–2881. © 2013 Wiley Periodicals, Inc.
Optimization of outdoor cultivation in flat panel airlift reactors for lipid production by Chlorella vulgaris
Authors: Münkel Ronja , Schmid‐Staiger Ulrike , Werner Achim , Hirth Thomas
Published: April 2013

Microalgae are discussed as a potential renewable feedstock for biofuel production. The production of highly concentrated algae biomass with a high fatty acid content, accompanied by high productivity with the use of natural sunlight is therefore of great interest. In the current study an outdoor pilot plant with five 30 L Flat Panel Airlift reactors (FPA) installed southwards were operated in 2011 in Stuttgart, Germany. The patented FPA reactor works on the basis of an airlift loop reactor and offers efficient intermixing for homogeneous light distribution. A lipid production process with the microalgae Chlorella vulgaris (SAG 211‐12), under nitrogen and phosphorous deprivation, was established and evaluated in regard to the fatty acid content, fatty acid productivity and light yield. In the first set of experiments limitations caused by restricted CO2 availability were excluded by enriching the media with NaOH. The higher alkalinity allows a higher CO2 content of supplied air and leads to doubling of fatty acid productivity. The second set of experiments focused on how the ratio of light intensity to biomass concentration in the reactor impacts fatty acid content, productivity and light yield. The specific light availability was specified as mol photons on the reactor surface per gram biomass in the reactor. This is the first publication based on experimental data showing the quantitative correlation between specific light availability, fatty acid content and biomass light yield for a lipid production process under nutrient deprivation and outdoor conditions. High specific light availability leads to high fatty acid contents. Lower specific light availability increases fatty acid productivity and biomass light yield. An average fatty acid productivity of 0.39 g L−1 day−1 for a 12 days batch process with a final fatty acid content of 44.6% [w/w] was achieved. Light yield of 0.4 g mol photons−1 was obtained for the first 6 days of cultivation. Biotechnol. Bioeng. 2013;110: 2882–2893. © 2013 Wiley Periodicals, Inc.
“Yes, I Have Sometimes Stolen Bikes”: Blindness for Norm‐Violating Behaviors and Implications for Suspect Interrogations
Authors: Sauerland Melanie , Schell Jennifer Maria , Collaris Jorg , Reimer Nils Karl , Schneider Marian , Merckelbach Harald
Published: April 2013

Across two experiments, we studied a phenomenon akin to choice blindness in the context of participants' accounts of their own history of norm‐violating behaviors. In Experiment 1, N = 67 participants filled in an 18‐item questionnaire about their history of norm‐violating behaviors (QHNVB). Subsequently, they were questioned about four of their answers, two of which had covertly been manipulated by the experimenter. Of the 134 manipulations, 20 (14.9%) remained undetected concurrently and 13 were accepted in retrospect (9.7%). In Experiment 2 (N = 37), we inserted a one‐week interval between questionnaire and interview. Twenty‐seven (36.5%) of the 74 manipulations remained undetected concurrently and three were accepted in retrospect (8.1%). Data obtained in a four‐week follow‐up indicated that our manipulations may have long‐term effects on participants' perception of their own history of norm‐violating behaviors. Implications for the occurrence of false confessions during the course of an interrogation are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
In non‐small cell lung cancer mitogenic signaling leaves Sprouty1 protein levels unaffected
Authors: Kral Rosana Maria , Mayer Christoph‐Erik , Vanas Vanita , Gsur Andrea , Sutterlüty‐Fall Hedwig
Published: April 2013

Sprouty1 protein belongs to a family of receptor tyrosine kinase‐mediated signaling inhibitors, whose members are usually regulated by growth factors to form a negative feedback loop. Correspondingly fluctuations of Sprouty1 mRNA in response to single growth factors have been observed.

In this report, we investigate Sprouty1 protein levels and show that in non‐small cell lung carcinoma‐derived cells, the expression levels are unaffected by the serum content in the cellular environment. Although cells harboring K‐Ras mutations express insignificant higher Sprouty1 levels, ectopic expression of constitutive active Ras in normal human lung fibroblasts fails to augment Sprouty1 protein content. Furthermore, serum starvation for three days has no influence on Sprouty1 expression and addition of serum or of singular growth factors leaves Sprouty protein levels unchanged. Cell cycle analysis reveals that Sprouty1 levels remain constant throughout the whole cell cycle. These data demonstrate that Sprouty1 expression is not connected with mitogenic signaling and cell proliferation. Copyright © 2013 John Wiley & Sons, Ltd.
ChemInform Abstract: K2FeGe3Se8: A New Antiferromagnetic Iron Selenide.
Authors: Feng Kai , Wang Wendong , He Ran , Kang Lei , Yin Wenlong , Lin Zheshuai , Yao Jiyong , Shi Youguo , Wu Yicheng
Published: April 2013

The title compound is synthesized from a mixture of K2Se, FeSe, and GeSe2 (silica tube, 1173 K, 48 h) and characterized by single crystal XRD, diffuse reflectance spectroscopy, specific heat and magnetic susceptibility measurements, and DFT calculations.
ChemInform Abstract: New Structure Type in the Mixed‐Valent Compound YbCu4Ga8.
Authors: Subbarao Udumula , Gutmann Matthias J. , Peter Sebastian C.
Published: April 2013

Large single crystals of YbCu4Ga8 are prepared by the metal flux technique using excess Ga as fluxing agent (evacuated quartz tube; 1.
ChemInform Abstract: Enhanced Photoresponsive Ultrathin Graphitic‐Phase C3N4 Nanosheets for Bioimaging.
Authors: Zhang Xiaodong , Xie Xiao , Wang Hui , Zhang Jiajia , Pan Bicai , Xie Yi
Published: April 2013

Ultrathin graphitic‐phase C3N4 nanosheets are prepared by a liquid exfoliation route from bulk C3N4 in water.
ChemInform Abstract: A Sodium Vanadium Three‐Fluorophosphate Cathode for Rechargeable Batteries Synthesized by Carbothermal Reduction.
Authors: Song Weixin , Liu Suqin
Published: April 2013

Na3V2(PO4)2F3 is synthesized by carbothermal reduction starting with stoichiometric amounts of NaF, Na2CO3, NH4H2PO4, V2O5, and acetylene black (flowing Ar, 350 °C for 8 h and 550—750 °C for 8 h).
ChemInform Abstract: [Sc2(μ‐OH)2(H2O)6 (NO3)2](NO3)2: Aqueous Synthesis and Characterization.
Authors: Wang Wei , Chang I‐Ya , Zakharov Lev , Cheong Paul Ha‐Yeon , Keszler Douglas A.
Published: April 2013

The title compound is synthesized in gram‐scale by addition of zinc metal powder to an aqueous solution of Sc(NO3)3(stirring, 24 h, 65% yield).
ChemInform Abstract: Enantioselective Heck Arylations of Acyclic Alkenyl Alcohols Using a Redox‐Relay Strategy.
Authors: Werner Erik W. , Mei Tian‐Sheng , Burckle Alexander J. , Sigman Matthew S.
Published: April 2013

An enantioselective variant of the Heck reaction that delivers β, γ, or δ‐aryl carbonyl products [cf.
ChemInform Abstract: Synthesis of Stable Acyclic Aminals Derived from L‐(+)‐Aspartic Acid and Their Application in Asymmetric Henry Reactions.
Authors: Koz Gamze , Astley Demet , Astley Stephen T.
Published: April 2013

A series of stable acyclic aminals derived from L‐aspartic acid are synthesized and successfully applied as chiral ligands in the Cu(II)‐catalyzed Henry reaction of nitromethane with various aromatic aldehydes.
ChemInform Abstract: Combining Transition Metal Catalysis with Radical Chemistry: Dramatic Acceleration of Palladium‐Catalyzed C—H Arylation with Diaryliodonium Salts.
Authors: Neufeldt Sharon R. , Sanford Melanie S.
Published: April 2013

A palladium‐catalyzed C—H arylation under extremely mild conditions is described.
ChemInform Abstract: An Efficient Synthesis of Symmetric and Unsymmetric Bis‐(β‐aminoamides) via Ugi Multicomponent Reaction.
Authors: La Spisa Fabio , Feo Alberto , Mossetti Riccardo , Tron Gian Cesare
Published: April 2013

Symmetrical and unsymmetrical bis‐(β‐aminoamides) are prepared starting from symmetrical secondary diamines by using a double Ugi four‐component reaction.
ChemInform Abstract: Ruthenium‐Catalyzed Reductive Coupling of 1,3‐Enynes and Aldehydes by Transfer Hydrogenation: anti‐Diastereoselective Carbonyl Propargylation.
Authors: Geary Laina M. , Leung Joyce C. , Krische Michael J.
Published: April 2013

Good levels of anti‐diastereoselectivity in propargylation of aliphatic aldehydes and enals are displayed by the presented ruthenium‐based catalyst system whereas the corresponding additions to aryl aldehydes remain unselective.
ChemInform Abstract: Synthesis of ortho‐Acylphenols Through the Palladium‐Catalyzed Ketone‐Directed Hydroxylation of Arenes.
Authors: Mo Fanyang , Trzepkowski Louis J. , Dong Guangbin
Published: April 2013

The title reaction provides various 2‐acylphenols by using the complementary methods A) and B), and an unusual ketal‐lactone [viz.
ChemInform Abstract: Enantioselective Nickel‐Catalyzed Hydrocyanation of Vinylarenes Using Chiral Phosphine—Phosphite Ligands and TMS‐CN as a Source of HCN.
Authors: Falk Anna , Goederz Anna‐Lena , Schmalz Hans‐Guenther
Published: April 2013

The absolute configuration of compound (IIIb) was determined to be (S) by chemical transformation to (S)‐(+)‐ibuprofen.
ChemInform Abstract: Copper Powder Catalyzed Direct Ring‐Opening Arylation of Benzazoles with Aryl Iodides in Polyethylene Glycol.
Authors: Yao Lifang , Zhou Qing , Han Wei , Wei Shaohua
Published: April 2013

This reaction yields aniline derivatives via ring opening of benzothiazoles or benzoxazoles, while thiazole and N‐methyl‐benzylimidazole do not react under these reaction conditions.
ChemInform Abstract: Rhenium‐Catalyzed Regio‐ and Stereoselective Synthesis of γ‐Thio‐α,β‐unsaturated Ketones via Insertion of Terminal Alkynes into the C—S Bond.
Authors: Nishi Mitsumi , Kuninobu Yoichiro , Takai Kazuhiko
Published: April 2013

This reaction is the first example of insertion of alkynes into a C—S bond of α‐thioketones affording the title compounds in good to high yields.
ChemInform Abstract: A Practical Isocyanide‐Based Multicomponent Synthesis of Polysubstituted Cyclopentenes.
Authors: Sagirli Akin , Dueruest Yasar , Kariuki Benson , Knight David W.
Published: April 2013

Polysubstituted cyclopentene derivatives (IV), (VI) are obtained by multicomponent reaction of β‐nitrostyrene, benzylidenemalononitriles, and 2‐morpholinoethyl isocyanide in the absence of any catalyst.
ChemInform Abstract: NiO—SnO2 Composite Nano‐Powder: Preparation and Evaluation of Their Catalytic Activity in the Synthesis of 1‐Amidoalkyl‐2‐naphtholes.
Authors: Dehbashi Mohsen , Aliahmad Mousa , Shafiee Mohammad R. M. , Ghashang Majid
Published: April 2013

Nano‐powder of NiO—SnO2 is prepared and applied as an efficient catalyst for the three‐component reaction of 2‐naphthol with aromatic aldehydes and amides or ureas (III).
ChemInform Abstract: Gold Catalysis: Catalyst Oxidation State Dependent Dichotomy in the Cyclization of Furan—Yne Systems with Aromatic Tethers.
Authors: Hashmi A. Stephen K. , et al. et al.
Published: April 2013

This method yields either fluorene derivatives or 2‐furyl‐substituted indene derivatives depending on the applied gold catalyst.
ChemInform Abstract: Palladium‐Catalyzed Carbonylative Coupling of Aryl Iodides and Benzyl Acetylenes to 3‐Alkylidenefuran‐2‐ones under Mild Conditions and Its Density Functional Theory Modeling.
Authors: Wu Xiao‐Feng , Jiao Haijun , Neumann Helfried , Beller Matthias
Published: April 2013

This is a general and efficient method for the preparation of furan‐2‐ones and alkynones under mild conditions in good to excellent yields.
ChemInform Abstract: Water‐Soluble Chiral Ruthenium(II) Phenyloxazoline Complex: Reusable and Highly Enantioselective Catalyst for Intramolecular Cyclopropanation Reactions.
Authors: Abu‐Elfotoh Abdel‐Moneim , Nguyen Diem Phuong Thi , Chanthamath Soda , Phomkeona Kesiny , Shibatomi Kazutaka , Iwasa Seiji
Published: April 2013

The easy separation of the cyclopropyl product, the water‐soluble catalyst, and the simple reuse of the catalyst at least five times without significant decrease in reactivity are advantages of this method.
ChemInform Abstract: Water Control over the Chemoselectivity of a Ti/Ni Multimetallic System: Heck‐ or Reductive‐Type Cyclization Reactions of Alkyl Iodides.
Authors: Millan Alba , Alvarez de Cienfuegos Luis , Miguel Delia , Campana Araceli G. , Cuerva Juan M.
Published: April 2013

In the presence of water, different alkyl iodides undergo reductive radical cyclization.
ChemInform Abstract: Versatile Pyrrole Synthesis Through Ruthenium(II)‐Catalyzed Alkene C—H Bond Functionalization on Enamines.
Authors: Wang Lianhui , Ackermann Lutz
Published: April 2013

Diversely substituted pyrroles are synthesized by the present new method.
ChemInform Abstract: Dual Nucleophilic/Electrophilic Capture of in situ Generated Iminium Ethers: Towards the Synthesis of Functionalized Amide Building Blocks.
Authors: Peng Bo , O'Donovan Daniel H. , Jurberg Igor D. , Maulide Nuno
Published: April 2013

The reaction proceeds via a cyclization followed by a Claisen rearrangement to yield iminium ether intermediates, which react with various nucleophiles.
ChemInform Abstract: From Alcohols to Indoles: A Tandem Ru Catalyzed Hydrogen‐Transfer Fischer Indole Synthesis.
Authors: Porcheddu Andrea , Mura Manuel G. , De Luca Lidia , Pizzetti Marianna , Taddei Maurizio
Published: April 2013

A new version of the Fischer indole synthesis is presented which uses primary and secondary alcohols instead of aldehydes.
ChemInform Abstract: Potassium Iodide Catalyzed Simultaneous C3‐Formylation and N‐Aminomethylation of Indoles with 4‐Substituted‐N,N‐dimethylanilines.
Authors: Li Lan‐Tao , Li Hong‐Ying , Xing Li‐Juan , Wen Li‐Juan , Wang Peng , Wang Bin
Published: April 2013

Various functionalized indole derivatives are prepared by a new one‐pot process under mild reaction conditions.
ChemInform Abstract: Palladium‐Catalyzed Intramolecular C—H Amidation: Synthesis and Biological Activities of Indolobenzazocin‐8‐ones.
Authors: Boonya‐udtayan Sasiwadee , Eno Meredith , Ruchirawat Somsak , Mahidol Chulabhorn , Thasana Nopporn
Published: April 2013

The title compounds are evaluated for their cytotoxicity against four cancer cell lines.
ChemInform Abstract: Direct C‐3‐Arylations of 1H‐Indazoles.
Authors: Ben‐Yahia Ali , Naas Mohammed , El Kazzouli Said , Essassi El Mokhtar , Guillaumet Gerald
Published: April 2013

These are the first examples for intermolecular C—H arylation of 1‐substituted indazoles.
ChemInform Abstract: Reaction of 1‐Nitroso‐2‐naphthols with α‐Functionalized Ketones and Related Compounds: The Unexpected Formation of Decarbonylated 2‐Substituted Naphtho[1,2‐d][1,3]oxazoles.
Authors: Aljaar Nayyef , Malakar Chandi C. , Conrad Juergen , Frey Wolfgang , Beifuss Uwe
Published: April 2013

The title reaction of nitroso‐2‐naphthols works well with various α‐functionalized ketones and tolerates aryl and allyl bromides, α‐bromo diketones, cyanides, and ketoesters, as well as α‐bromoesters providing an efficient access to numerous annulated oxazoles.
ChemInform Abstract: Novel 4‐Trifluoromethylthiazole‐5‐carboxylic Acid as Acceptor in Photosensitized Dyes
Authors: Iwata Satoru , Aoyama Misa , Uchida Satoshi , Tanaka Kiyoshi
Published: April 2013

synthesis and characterization
ChemInform Abstract: Synthesis and Antioxidant Activity of a New Class of Mono‐ and Bis‐heterocycles.
Authors: Reddy Guda Mallikarjuna , Reddy Putta Ramachandra , Padmavathi Venkatapuram , Padmaja Adivireddy
Published: April 2013

Novel highly functionalized mono‐ and bis‐heterocycles (VI)—(XI) are synthesized and tested for their antioxidant properties.
ChemInform Abstract: A Short and Flexible Route to Tetrahydropyran‐4‐ones via Conjugated Nitrile Oxides Cycloaddition and Oxa‐Michael Cyclization: A Concise Diastereoselective Total Synthesis of (.+‐.)‐Diospongin A.
Authors: Yao Hongliang , Ren Jingyun , Tong Rongbiao
Published: April 2013

A convenient four step procedure is developed for the synthesis of tetrahydropyranones (IV) based on the conversion of unsaturated aldehydes (I) into corresponding nitrile oxides, 1,3‐dipolar cycloaddition, SmI2‐mediated reductive ring‐opening of resulting isoxazolines (III), and Amberlyst‐15 promoted 6‐endo‐trig oxa‐Michael cyclization of intermediate β‐hydroxyenones.
ChemInform Abstract: Rhodium or Ruthenium‐Catalyzed Oxidative C—H/C—H Cross‐Coupling: Direct Access to Extended π‐Conjugated Systems.
Authors: Dong Jiaxing , Long Zhen , Song Feijie , Wu Ningjie , Guo Qiang , Lan Jingbo , You Jingsong
Published: April 2013

This method is highly chemo‐ and regioselective and applicable to a broad variety of heteroarenes.
ChemInform Abstract: Silver‐Catalyzed Cyclization of N‐(Prop‐2‐yn‐1‐yl)pyridin‐2‐amines.
Authors: Chioua Mourad , Soriano Elena , Infantes Lourdes , Jimeno M. Luisa , Marco‐Contelles Jose , Samadi Abdelouahid
Published: April 2013

This reaction yields 3‐methyl‐imidazo[1,2‐α]pyridines (II) from readily available substrates.
ChemInform Abstract: Three‐Component Stereoselective Synthesis of Spirooxindole Derivatives
Authors: Yu Fuchao , Huang Rong , Ni Hangchen , Fan Juan , Yan Shengjiao , Lin Jun
Published: April 2013

by refluxing mixtures of heterocyclic ketene aminals with isatins (I) and trifluoroacetate (III)
ChemInform Abstract: Synthesis of trans‐1,3‐Diaryl‐2‐(5‐methylisoxazol‐3‐yl)‐2,3‐dihydro‐1H‐naphtho [1,2‐e][1,3]oxazines via Bismuth(III)‐Catalyzed One‐Pot pseudo‐Four Component Reaction.
Authors: Shafiee Mehdi , Khosropour Ahmad Reza , Mohammadpoor‐Baltork Iraj , Moghadam Majid , Tangestaninejad Shahram , Mirkhani Valiollah , Khavasi Hamid Reza
Published: April 2013

This is a solvent‐free one‐pot multicomponent reaction which gives naphtho[1,2‐e][1,3]oxazines in good yields and with good diastereoselectivity.
ChemInform Abstract: 1,2‐ and 1,4‐Additions of 2‐Alkynylcyclohexadienimines with Aromatic Amines to Access 4‐Amino‐N‐arylindoles and ‐azepinoindoles.
Authors: Zhang Li , Li Zhiming , Fan Renhua
Published: April 2013

Alkynylcyclohexadienimines (I) derived from the oxidation of alkynylanilines react with aromatic amines to 4‐aminoarylindoles.
ChemInform Abstract: An Unusual Silicon Mediated Transannular Cyclopropanation.
Authors: You Bing , Hamer Kate , Lewis William , Dowden James
Published: April 2013

The treatment of readily available 5,6‐dihydroazocinones (V) with tetrabutylammonium fluoride leads to fused cyclopropane derivatives (VI) as a result of a transannular cyclopropanation.
ChemInform Abstract: Efficient Metathesis of Terminal Alkynes.
Authors: Haberlag Birte , Freytag Matthias , Daniliuc Constantin G. , Jones Peter G. , Tamm Matthias
Published: April 2013

For the first time, terminal ring‐closing alkyne metathesis (TRAM) is accomplished; only one other related example with 25% yield exists in the literature.
ChemInform Abstract: Synthesis of Azaaromatic—Borane Intramolecular Complexes by Palladium‐Catalyzed Reaction of Azaaromatic Halides with Alkynyl(triaryl)borates.
Authors: Ishida Naoki , Narumi Mizuna , Murakami Masahiro
Published: April 2013

A versatile method for the synthesis of (E)‐azastilbenes with an intramolecular B‐N coordination is presented for a wide variety of azaaromatics.
ChemInform Abstract: Straightforward Iron‐Catalyzed Synthesis of Vinylboronates by the Hydroboration of Alkynes.
Authors: Haberberger Michael , Enthaler Stephan
Published: April 2013

The iron‐catalyzed hydroboration of terminal alkynes (I) affords selectively the corresponding (E)‐isomer (III) in high yields.
ChemInform Abstract: Highly Chemoselective Metal‐Free Reduction of Phosphine Oxides to Phosphines.
Authors: Li Yuehui , Lu Liang‐Qiu , Das Shoubhik , Pisiewicz Sabine , Junge Kathrin , Beller Matthias
Published: April 2013

A new, mild, and chemoselective method for the conversion of phosphine oxides into phosphines is reported.
ChemInform Abstract: Nickel‐Catalyzed C—P Cross‐Coupling of Diphenylphosphine Oxide with Aryl Chlorides.
Authors: Zhang Hong‐Yu , Sun Meng , Ma Yan‐Na , Tian Qiu‐Ping , Yang Shang‐Dong
Published: April 2013

Various diphenylphosphoryl compounds (III) and (V) are prepared using a simple and mild method.
ChemInform Abstract: Regioselective Formation of Tetrahydroselenophenes via 5‐exo‐dig‐Cyclization of 1‐Butylseleno‐4‐alkynes.
Authors: Gai Rafaela M. , Schumacher Ricardo F. , Back Davi F. , Zeni Gilson
Published: April 2013

Electrophilic cyclization of butylselenoalkynes with iodine results in the formation of the title compounds which can be used for further transformations such as cyanation, Suzuki and Ullmann coupling reactions.
ChemInform Abstract: Lignans from Schisandra sphenathera Rehd. et Wils. and Semisynthetic Schisantherin A Analogues: Absolute Configuration, and Their Estrogenic and anti‐Proliferative Activity.
Authors: Liu Han‐Wei , Yu Xiu‐Zhu , Padula Daniele , Pescitelli Gennaro , Lin Zhi‐Wei , Wang Fei , Ding Kai , Lei Ming , Gao Jin‐Ming
Published: April 2013

Derivatives (I) and (II) show very potent estrogenic effects.
ChemInform Abstract: Reduction and Oxidation of Transition‐Metal Oxide Thin Films: Solid‐State Chemistry with Epitaxially Grown Thin Films
Authors: Shimakawa Yuichi
Published: April 2013

Review: 44 refs.
ChemInform Abstract: Preactivation: An Alternative Strategy in Stereoselective Glycosylation and Oligosaccharide Synthesis
Authors: Yang Lin , Qin Qi , Ye Xin‐Shan
Published: April 2013

Review: 174 refs.
ChemInform Abstract: Advances in the Synthesis of Calystegines and Related Products and Their Biochemical Properties
Authors: Pino‐Gonzalez M. S. , Ona N. , Romero‐Carrasco A.
Published: April 2013

Review: 70 refs.
ChemInform Abstract: Far‐Red to Near Infrared Analyte‐Responsive Fluorescent Probes Based on Organic Fluorophore Platforms for Fluorescence Imaging
Authors: Yuan Lin , Lin Weiying , Zheng Kaibo , He Longwei , Huang Weimin
Published: April 2013

Review: 240 refs.
ChemInform Abstract: The Li‐Ion Rechargeable Battery: A Perspective
Authors: Goodenough John B. , Park Kyu‐Sung
Published: April 2013

Review: 50 refs.
Asymmetric Zinc‐Catalyzed Hydrosilylation of Ketones and the Effect of Carboxylate on the Enantioselectivity
Authors: Pang Shaofeng , Peng Jiajian , Li Jiayun , Bai Ying , Xiao Wenjun , Lai Guoqiao
Published: April 2013

Several chiral ligands containing (R,R)‐diaminocyclohexane moieties and pyrrole, furan, or benzene have been synthesized. These ligands were tested in enantioselective zinc‐catalyzed hydrosilylation reactions; excellent enantioselectivities were obtained when the ligands containing (R,R)‐diaminocyclohexane moieties and furan rings were used. For comparison, zinc chloride combined with different potassium carboxylate salts and ligands were also tested for catalytic hydrosilylation reactions. Chirality 25:275–280, 2013. © 2013 Wiley Periodicals, Inc.
Infrared Spectroscopy Using ATR Probe Technology
Authors: Lüttjohann Stephan
Published: April 2013

Infrarotspektroskopie ist eine aussagekräftige Analysemethode, die auf charakteristischen Absorptionen von infraroter Strahlung bei der Anregung von Molekülschwingungen beruht. Gerade im Bereich zwischen 400 – 4000 cm–1 ergeben sich stark ausgeprägte Absorptionsbanden, die die Identifikation von Molekülen und Molekülgruppen möglich machen. Die hohe Absorptionsstärke erfordert für Transmissionsmessungen erhöhte Probenpräparation. So können nur Schichtdicken von wenigen Mikrometern verwendet werden. Bei der abgeschwächten Totalreflexion (ATR) sind solche Anstrengungen dagegen nicht erforderlich. Hier ist es ausreichend, beispielsweise eine Flüssigkeit in Kontakt mit einem ATR‐Kristall zu bringen. ATR‐Messsonden ermöglichen es, diese einfache Technik auch zur Online‐Überwachung an chemischen Reaktoren einzusetzen.
Fermentative Production of Monorhamnolipids in Pilot Scale – Challenges in Scale‐Up
Authors: Küpper Benjamin , Mause Anika , Halka Lisa , Imhoff Adam , Nowacki Christian , Wichmann Rolf
Published: April 2013

Die fermentative Herstellung von Biotensiden wird meist durch die exzessive Bildung von stabilem Schaum erschwert. Am Beispiel von Monorhamnolipiden werden Vorschläge sowohl zur stabilen Aufrechterhaltung von begasten und gerührten Fermentationen wie auch zur Isolierung dieser Biotenside im größeren Maßstab gegeben, da diese kommerziell nur in sehr kleinen Mengen erhältlich sind. Ein besonderer Fokus liegt dabei auf der Verwendung nachwachsender Rohstoffe.
Omix – A Visualization Tool for Metabolic Networks with Highest Usability and Customizability in Focus
Authors: Droste Peter , Nöh Katharina , Wiechert Wolfgang
Published: April 2013

Visualization has become indispensable in the analysis and interpretation of data from experiment and simulation. To adequately represent the diversity of studied phenomena, it is necessary to support researchers with tools that are easy to use and allow effective data visualization with special regard to individual requirements. This contribution presents the visualization tool Omix, an editor for metabolic network diagrams and a customizable visualization framework. As an outstanding feature, data visualization is script‐based. The dedicated new scripting language OVL (Omix Visualization Language) enables the user to freely design the manner data is visualized in the network. An intuitive user interface, several newly developed, domain‐specific drawing automatisms as well as visualization concepts make the software Omix a mature computational tool supporting the specific requirements of researchers from systems biology and life science domains as will be demonstrated on several application examples.
Synthesis and in vitro Evaluation of West Nile Virus Protease Inhibitors Based on the 2‐{6‐[2‐(5‐Phenyl‐4H‐{1,2,4]triazol‐3‐ylsulfanyl)acetylamino]benzothiazol‐2‐ylsulfanyl}acetamide Scaffold
Authors: Samanta Sanjay , Lim Ting Liang , Lam Yulin
Published: April 2013

In recent years, clinical symptoms resulting from West Nile virus (WNV) infection have worsened in severity, with an increased frequency in neuroinvasive diseases among the elderly. As there are presently no successful therapies against WNV for use in humans, continual efforts to develop new chemotherapeutics against this virus are highly desired. The viral NS2B‐NS3 protease is a promising target for viral inhibition due to its importance in viral replication and its unique substrate preference. In this study, a WNV NS2B‐NS3 protease inhibitor with a 2‐{6‐[2‐(5‐phenyl‐4H‐[1,2,4]triazol‐3‐ylsulfanyl)acetylamino]benzothiazol‐2‐ylsulfanyl}acetamide scaffold was identified during screening. Optimization of this initial hit by synthesis and screening of a focused compound library with this scaffold led to the identification of a novel uncompetitive inhibitor (1 a24, IC50=3.4±0.2 μM) of the WNV NS2B‐NS3 protease. Molecular docking of 1 a24 into the WNV protease showed that the compound interferes with productive interactions of the NS2B cofactor with the NS3 protease and is an allosteric inhibitor of the WNV NS3 protease.
Design of a quadrature surface coil for hyperpolarized 13C MRS cardiac metabolism studies in pigs
Authors: Giovannetti G. , Frijia F. , Hartwig V. , Attanasio S. , Menichetti L. , Vanello N. , Positano V. , Ardenkjaer‐Larsen J.H. , Lionetti V. , Aquaro G.D. , Marchi D. De , Schulte R.F. , Wiesinger F. , Landini L. , Lombardi M. , Santarelli M.F.
Published: April 2013

This work describes the design of a quadrature surface coil constituted by a circular loop and a butterfly coil, employed in transmit/receive (TX/RX) mode for hyperpolarized 13C studies of pig heart with a clinical 3T scanner. The coil characterization is performed by developing an SNR model for coil performance evaluation in terms of coil resistance, sample‐induced resistance and magnetic field pattern. Experimental SNR‐vs.‐depth profiles, extracted from the [1–13C]acetate phantom chemical shift image (CSI), showed good agreement with the theoretical SNR‐vs.‐depth profiles. Moreover, the performance of the quadrature coil was compared with the single TX/RX circular and TX/RX butterfly coil, in order to verify the advantage of the proposed configuration over the single coils throughout the volume of interest for cardiac imaging in pig. Finally, the quadrature surface coil was tested by acquiring metabolic maps with hyperpolarized [1–13C]pyruvate injected i.v. in a pig. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B: 69–77, 2013
Consideration of comorbidity in risk stratification prior to prostate biopsy
Authors: Liss Michael A. , Billimek John , Osann Kathryn , Cho Jane , Moskowitz Ross , Kaplan Adam , Szabo Richard J. , Kaplan Sherrie H. , Greenfield Sheldon , Dash Atreya
Published: April 2013

BACKGROUND

Previously, the patient‐reported Total Illness Burden Index for Prostate Cancer (TIBI‐CaP) questionnaire and/or the physician‐reported Charlson Comorbidity Index (CCI) have provided assessments of competing comorbidity during treatment decisions for patients with prostate cancer. In the current study, the authors used these assessments to determine comorbidity and prognosis before prostate biopsy and the subsequent diagnosis of prostate cancer to identify those patients least likely to benefit from treatment.

METHODS

A prospective observational cohort study was performed of 104 participants aged 64.0 years ± 6.5 years from 3 institutions representing different health care delivery systems. Patients were identified before undergoing transrectal ultrasound‐guided prostate biopsy and followed for a median of 28 months. Associations between the comorbidity scores and nonelective hospital admissions were investigated using logistic regression and Cox proportional hazards models.

RESULTS

Among the 104 patients who underwent prostate biopsy, 2 died during the follow‐up period. The overall hospital admission rate was 20% (21 of 104 patients). Higher scores on both the TIBI‐CaP (≥ 9) and CCI (≥ 3) were found to be significantly associated with an increased odds for hospital admission (odds ratio, 11.3 [95% confidence interval (95% CI), 2.4‐53.6] and OR, 5.7 [95% CI, 1.4‐22.4]) and hazards ratios (HRs) for time to hospital admission (HR, 3.8 [95% CI, 1.3‐11.2] and HR, 3.2 [95% CI, 1.1‐9.1]), respectively.

CONCLUSIONS

TIBI‐CaP and CCI scores were found to successfully predict which patients were at high risk for nonelective hospital admission. These patients are likely to have poorer health and a potentially shortened lifespan. Therefore, comorbidity analysis using these tools may help to identify those patients who are least likely to benefit from prostate cancer therapy and should avoid prostate biopsy. Cancer 2013;119:2413‐2418. © 2013 American Cancer Society.
The Factors Influencing Nonlinear Characteristics of the Short‐Circuit Current in Dye‐Sensitized Solar Cells Investigated by a Numerical Model
Authors: Shi Yushuai , Dong Xiandui
Published: April 2013

A numerical model for interpretation of the light‐intensity‐dependent nonlinear characteristics of the short‐circuit current in dye‐sensitized solar cells is suggested. The model is based on the continuity equation and includes the influences of the nongeminate recombination between electrons and electron acceptors in the electrolyte and the geminate recombination between electrons and oxidized dye molecules. The influences of the order and rate constant of the nongeminate recombination reaction, the light‐absorption coefficient of the dye, the film thickness, the rate constant of geminate recombination, and the regeneration rate constant on the nonlinear characteristics of the short‐circuit current are simulated and analyzed. It is proposed that superlinear and sublinear characteristics of the short‐circuit current should be attributed to low electron‐collection efficiency and low dye‐regeneration efficiency, respectively. These results allow a deep understanding of the origin of the nonlinear characteristics of the short‐circuit current in solar cells.
Cooperative bargaining solution for efficient and fair spectrum management in cognitive wireless networks
Authors: Guan Zhangyu , Yuan Dongfeng , Zhang Haixia , Ding Lei
Published: April 2013

This paper studies the fairness among the primary users (PUs) and the secondary users (SUs) for resource allocation in cognitive radio systems. We propose a novel co‐opetition strategy based on the Kalai–Smorodinsky bargaining solution to balance the system efficiency and the fairness among users. The strategy formulates the spectrum sharing problem as a nonlinear and integral sum utility maximization subject to a set of constraints describing the co‐opetition among the PUs and the SUs. Then, we solve the maximization problem by proposing a heuristical method that consists of four steps: multi‐PU competition, PU's subcarrier contribution, multi‐SU competition, and SU's subcarrier contribution. Extensive simulation results are presented by comparing the co‐opetition strategy with several conventional ones, including the Kalai–Smorodinsky bargaining solution, sum rate maximization as well as the Max–Min. Results indicate that the co‐opetition strategy can jointly balance the system efficiency and fairness in multiuser resource allocation, as it is able to support more satisfied users and in the meanwhile improve the utility of those unsatisfied. Moreover, the co‐opetition can help enable the coexistence of the PUs and the SUs in cognitive radio systems. Copyright © 2013 John Wiley & Sons, Ltd.
Reevaluation of a classic phylogeographic barrier: new techniques reveal the influence of microgeographic climate variation on population divergence
Authors: Soto‐Centeno J. Angel , Barrow Lisa N. , Allen Julie M. , Reed David L.
Published: April 2013

We evaluated themtDNAdivergence and relationships withinGeomys pinetisto assess the status of formerly recognizedGeomystaxa. Additionally, we integrated new hypothesis‐based tests in ecological niche models (ENM) to provide greater insight into causes for divergence and potential barriers to gene flow in SoutheasternUnitedStates (Alabama,Florida, andGeorgia). OurDNAsequence dataset confirmed and strongly supported two distinct lineages withinG. pinetisoccurring east and west of theARD. Divergence date estimates showed that eastern and western lineages diverged about 1.37 Ma (1.9 Ma–830 ka). Predicted distributions fromENMswere consistent with molecular data and defined each population east and west of theARDwith little overlap. Niche identity and background similarity tests were statistically significant suggesting thatENMsfrom eastern and western lineages are not identical or more similar than expected based on random localities drawn from the environmental background.ENMsalso support the hypothesis that theARDrepresents a ribbon of unsuitable climate between more suitable areas where these populations are distributed. The estimated age of divergence between eastern and western lineages ofG. pinetissuggests that the divergence was driven by climatic conditions during Pleistocene glacial–interglacial cycles. TheARDat the contact zone of eastern and western lineages ofG. pinetisforms a significant barrier promoting microgeographic isolation that helps maintain ecological and genetic divergence.
Alarmin‐induced cell migration
Authors: Yang De , Wei Feng , Tewary Poonam , Howard O. M. Zack , Oppenheim Joost J.
Published: April 2013

Alarmins are endogenous, constitutively available, damage‐associated molecular patterns that upon release can mobilize and activate various leukocytes for the induction of innate and adaptive immune responses. For our immune system to function appropriately, it relies on navigating various leukocytes to distinct places at the right time. The direction of cell migration is determined by chemotactic factors that include classical chemoattractants, chemokines, certain growth factors, and alarmins. This viewpoint provides an overview of alarmin‐induced cell migration. Alarmins are capable of inducing the migration of diverse types of leukocytes and nonleukocytes either directly by triggering specific receptors or indirectly by inducing production of chemokines through the activation of various leukocytes via pattern recognition receptors. The receptors used by alarmins to directly induce cell migration can either be Gαi protein‐coupled receptors or receptors such as the receptor for advanced glycation end products; however, the intracellular signaling events responsible for the direct chemotactic activities of alarmins are, to date, only partially elucidated. Given that alarmins act in concert with chemokines to regulate the recruitment and trafficking of leukocytes, these damage‐associated molecular patterns are potentially involved in diverse biological processes as discussed in this viewpoint.
Platinum(II) Acetylides in the Formal [2+2] Cycloaddition‐Retroelectrocyclization Reaction: Organodonor Versus Metal Activation
Authors: Tchitchanov Boris H. , Chiu Melanie , Jordan Markus , Kivala Milan , Schweizer W. Bernd , Diederich François
Published: April 2013

Formal cycloaddition‐retroelectrocyclization (CA‐RE) reactions between electron‐donor‐activated alkynes and electron‐poor alkenes yielding cyanobuta‐1,3‐dienes have recently attracted increasing interest. The transformation has been subjected to a fundamental investigation of the relative degrees of alkyne activation by organic and metallorganic donor substituents by using platinum(II) σ‐acetylides as model substrates and studying their behavior towards the cyano carbons TCNE and TCNQ. Various cyanobutadienes were obtained in good to excellent yields and four trends in reactivity were discerned: 1) The presence of an anilino substituent clearly dominates the regioselectivity of the TCNQ addition. 2) In the absence of an organodonor, the regioselectivity is inverted. 3) When platinum(II) complexes of buta‐1,3‐diynes are used, the addition always takes place at the triple bond distal to the metal center. 4) In general, trans‐bis‐acetylides are more reactive than the corresponding cis complexes. The structural parameters of the CA‐RE adducts were investigated by X‐ray crystallography and their optical properties by UV/Vis spectroscopy, giving further insights into the structural trends and degree of intramolecular charge transfer. These fundamental investigations may enable the synthesis of new Pt‐based molecular dyads in which the effect of regioselectivity on photoinduced charge separation can be studied.
NFATc3 promotes Ca2+‐dependent MMP3 expression in astroglial cells
Authors: Neria Fernando , del Carmen Serrano‐Perez María , Velasco Patricia , Urso Katia , Tranque Pedro , Cano Eva
Published: April 2013

Increase in intracellular calcium ([Ca2+]i) is a key mediator of astrocyte signaling, important for activation of the calcineurin (CN)/nuclear factor of activated T cells (NFAT) pathway, a central mediator of inflammatory events. We analyzed the expression of matrix metalloproteinase 3 (Mmp3) in response to increases in [Ca2+]iand the role of the CN/NFAT pathway in this regulation. AstrocyteMmp3expression was induced by overexpression of a constitutively active form of NFATc3, whereas other MMPs and tissue inhibitor of metalloproteinases (TIMP) were unaffected.Mmp3mRNA and protein expression was also induced by calcium ionophore (Io) and 2′(3′)‐O‐(4‐benzoylbenzoyl) adenosine 5′‐triphosphate (Bz‐ATP) andMmp3upregulation was prevented by the CN inhibitor cyclosporin A (CsA). Ca2+‐dependent astrocyteMmp3expression was also inhibited by actinomycin D, and aMmp3promoter luciferase reporter was efficiently activated by increased [Ca2+]i, indicating regulation at the transcriptional level. Furthermore, Ca2+/CN/NFAT dependentMmp3expression was confirmed in pure astrocyte cultures derived from neural stem cells (Ast‐NSC), demonstrating that the inducedMmp3expression occurs in astrocytes, and not microglial cells. In anin vivostab‐wound model of brain injury, MMP3 expression was detected in NFATc3‐positive scar‐forming astrocytes. Because [Ca2+]iincrease is an early event in most brain injuries, these data support an important role for Ca2+/CN/NFAT‐induced astrocyte MMP3 expression in the early neuroinflammatory response. Understanding the molecular pathways involved in this regulation could provide novel therapeutic targets and approaches to promoting recovery of the injured brain.
Phosphorylation of rat aquaporin‐4 at Ser111 is not required for channel gating
Authors: Assentoft Mette , Kaptan Shreyas , Fenton Robert A. , Hua Susan Z. , de Groot Bert L. , MacAulay Nanna
Published: April 2013

Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain‐blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4 is therefore of therapeutic interest. Phosphorylation of some aquaporins has been proposed to regulate their water permeability via gating of the channel itself. Protein kinase (PK)‐dependent phosphorylation of Ser111 has been reported to increase the water permeability of AQP4 expressed in an astrocytic cell line. This possibility was, however, questioned based on the crystal structure of the human AQP4. Our study aimed to resolve if Ser111 was indeed a site involved in phosphorylation‐mediated gating of AQP4. The water permeability of AQP4‐expressing Xenopus oocytes was not altered by a range of activators and inhibitors of PKG and PKA. Mutation of Ser111 to alanine or aspartate (to prevent or mimic phosphorylation) did not change the water permeability of AQP4. PKG activation had no effect on the water permeability of AQP4 in primary cultures of rat astrocytes. Molecular dynamics simulations of a phosphorylation of AQP4.Ser111 recorded no phosphorylation‐induced change in water permeability. A phospho‐specific antibody, exclusively recognizing AQP4 when phosphorylated on Ser111, failed to detect phosphorylation in cell lysate of rat brain stimulated by conditions proposed to induce phosphorylation of this residue. Thus, our data indicate a lack of phosphorylation of Ser111 and of phosphorylation‐dependent gating of AQP4.
Variation in total electron content above large thunderstorms
Authors: Lay Erin H. , Shao Xuan‐Min , Carrano Charles S.
Published: April 2013

Total electron content (TEC) measured by Global Positioning System (GPS) receivers in the United States Great Plains is examined for three nights with large thunderstorms and for one night with little thunderstorm activity. The GPS TEC data are fit with a polynomial, and the variations are estimated by subtracting this fit from the data. We found that anomalous TEC variations are closely associated in time and space to the large underlying thunderstorms. The largest storm‐related TEC variation is observed to be ~1.4 total electron content unit (TECU) over a typical nighttime background value of several TECUs. The variations near the storm appear to have more high‐frequency content than those away from the storm, with periods of minutes to tens of minutes. No detectable localized TEC variation is observed for the thunderstorm‐quiet night.
The importance of ebullition as a mechanism of methane (CH4) loss to the atmosphere in a northern peatland
Authors: Stamp Imelda , Baird Andy J. , Heppell Catherine M.
Published: April 2013

We measured the escape of methane‐containing gas bubbles to the water table in two microhabitats (muddy hollows and Sphagnum‐plus‐sedge lawns) in a raised bog in West Wales, typical of many northern peatlands. Our study was unusual in its degree of replication (14 gas traps in each microhabitat). Seasonally integrated bubble loss of CH4 to the water table did not differ significantly between microhabitats. After applying an oxidation correction to give CH4 fluxes to the atmosphere, the microhabitats still did not differ. Our results suggest that ebullition is an important mechanism of CH4 loss to the atmosphere, with mean summer rates of 11.7 mg CH4 m−2 d−1 (muddy hollows) and 6.8 mg CH4 m−2 d−1 (Sphagnum‐plus‐sedge lawns). Our data show that the process is spatially and temporally very variable, and that the small sample sizes of many studies (e.g., n = 5) may lead to considerable errors in flux estimation.