bluuebunny/crossref_metadata_2025 huggingface dataset:
Extreme events and long-range correlations in space weather
Authors: Sharma A. S. , Veeramani T.
Published: October 2011

Abstract. Space weather is driven by the solar wind and many geospace storms and substorms are natural hazards with considerable societal impact. The dynamical and statistical features of these events are complicated because of the turbulent nature of their driver, the solar wind. Large-scale data sets of geospace storms and substorms are analysed for this study of the inherent statistical characteristics of extreme events in geospace. The detrended fluctuation analysis, based on the autocorrelation functions, is used and yields scaling behavior representing long-term correlations. The scaling function is represented by two exponents, arising due mainly to the presence of the largely coherent internal dynamics of the magnetosphere and the turbulent nature of the solar wind driver.
Ensemble Kalman filtering without the intrinsic need for inflation
Authors: Bocquet M.
Published: October 2011

Abstract. The main intrinsic source of error in the ensemble Kalman filter (EnKF) is sampling error. External sources of error, such as model error or deviations from Gaussianity, depend on the dynamical properties of the model. Sampling errors can lead to instability of the filter which, as a consequence, often requires inflation and localization. The goal of this article is to derive an ensemble Kalman filter which is less sensitive to sampling errors. A prior probability density function conditional on the forecast ensemble is derived using Bayesian principles. Even though this prior is built upon the assumption that the ensemble is Gaussian-distributed, it is different from the Gaussian probability density function defined by the empirical mean and the empirical error covariance matrix of the ensemble, which is implicitly used in traditional EnKFs. This new prior generates a new class of ensemble Kalman filters, called finite-size ensemble Kalman filter (EnKF-N). One deterministic variant, the finite-size ensemble transform Kalman filter (ETKF-N), is derived. It is tested on the Lorenz '63 and Lorenz '95 models. In this context, ETKF-N is shown to be stable without inflation for ensemble size greater than the model unstable subspace dimension, at the same numerical cost as the ensemble transform Kalman filter (ETKF). One variant of ETKF-N seems to systematically outperform the ETKF with optimally tuned inflation. However it is shown that ETKF-N does not account for all sampling errors, and necessitates localization like any EnKF, whenever the ensemble size is too small. In order to explore the need for inflation in this small ensemble size regime, a local version of the new class of filters is defined (LETKF-N) and tested on the Lorenz '95 toy model. Whatever the size of the ensemble, the filter is stable. Its performance without inflation is slightly inferior to that of LETKF with optimally tuned inflation for small interval between updates, and superior to LETKF with optimally tuned inflation for large time interval between updates.
Association of HSV-1 Antigen Distribution in the Cornea with Clinical Characteristics of Herpetic Stromal Keratitis
Authors: Zhao Ge , Chen Min , Liu Ting , Sun Shi Y. , Zhao Jing , Xie Li X.
Published: October 2011

Purpose

To investigate whether the clinical characteristics of stromal herpetic simplex keratitis (HSK) are associated with herpes simplex virus type 1 (HSV-1) antigens distribution in the pathologic cornea.

Materials and Methods

Pathologic corneal buttons from 8 eyes were obtained during keratoplasty at the Shandong Eye Institute from 2006 to 2009. Immunohistochemical examination was performed to detect the distribution of HSV-1 antigens, including position, depth, and load in the cornea.

Results

Each of the 8 pathologic corneal buttons was positive for HSV-1 antigen by immunohistochemical staining, and HSV-1 antigen was detected in the corneal stroma but not in the corneal epithelium or endothelium. Combined with the clinical characteristics, it was found that the distribution depth of HSV-1 antigen in the cornea was partly related to the disease course, and the load was related to the delay time for treatment. Furthermore, HSK could be effectively cured by deep anterior lamellar keratoplasty (DALK).

Conclusions

The distribution characteristics of HSV-1 in HSK corneal stroma supports the theory of HSV-1 latency in the cornea and guides the selection of DALK, rather than penetrating keratoplasty (PKP), for clinical stromal HSK treatment.
Improvement and Multicenter Evaluation of the Analytical Performance of an Automated Chemiluminescent Immunoassay for Alpha Fetoprotein
Authors: Morota Kaori , Komori Makoto , Fujinami Ryo , Yamada Koji , Kuribayashi Kageaki , Watanabe Naoki , Sokoll Lori J. , Elliott Debra , Chan Daniel W. , Martens Frans , Heijboer Annemieke C. , Blankenstein Marinus A. , Hershberger Stefan J. , Pfeiffer Zachary A. , Vaidya Shyam V. , Dowell Barry L.
Published: October 2011

Background

A new ARCHITECT® alpha fetoprotein (AFP) assay was developed to improve the linearity at the upper end of the calibration curve and to enhance other performance characteristics. In addition, this reformulation eliminated the possibility of falsely depressed samples at high AFP concentrations. The purpose of this study was to evaluate its analytical performance at multiple sites.

Methods

The assay configuration, the diluent formulation, and the manufacturing process were redesigned. Analytical performance was evaluated at Abbott Laboratories, Sapporo Medical University, VU University Medical Center, and Johns Hopkins University.

Results

The limit of quantitation of the assay was 1.00–1.30 ng/mL. Total precision (%CV) across the assay range varied between 1.41 and 3.52. The assay was linear from 1.19 to 2535 ng/mL, and the range of the assay was expanded from 200 ng/mL to 2000 ng/mL. Comparison of this assay with the on-market ARCHITECT, AxSYM, ADVIA Centaur, DxI, AIA-1800, and E 170 systems yielded regression slopes of 0.91–1.08 and correlation coefficients of ≥0.99 for serum samples. No falsely depressed results were observed in 174 serum samples with AFP concentrations of 2018–1,196,856 ng/mL and in a spiked sample containing up to 10 mg/mL of purified AFP.

Conclusions

The new AFP assay has improved an issue of the on-market ARCHITECT AFP assay and demonstrated excellent assay performance.
Stable Emission of SnO2 Nanowires Array at Low Field
Authors: Wang Lingjie , Lin Jinyang , Ye Yun , Guo Tailiang
Published: October 2011

SnO2 nanowires were synthesized by thermal evaporation, and the field emission characteristics of SnO2 nanowires are investigated in detail. The results show that the turn-on field is as low as 1.39 V/μm. And the fluctuation of field emission currents is as low as 2.8% for 24 h. The results reveal that SnO2 nanowires hold promise for field emission display application.
Ruthenium‐Catalyzed Asymmetric Hydrogenation of β‐Keto‐ enamines: An Efficient Approach to Chiral γ‐Amino Alcohols
Authors: Geng Huiling , Zhang Xiaowei , Chang Mingxin , Zhou Le , Wu Wenjun , Zhang Xumu
Published: October 2011

A highly efficient and enantioselective hydrogenation of unprotected β‐ketoenamines catalyzed with ruthenium(II) dichloro{(S)‐(−)‐2,2′‐bis[di(3,5‐xylyl)phosphino]‐1,1′‐binaphthyl}[(2S)‐(+)‐1,1‐bis(4‐methoxyphenyl)‐3‐methyl‐1,2‐butanediamine] {Ru[(S)‐xylbinap][(S)‐daipen]Cl2} has been successfully developed. This methodology provides a straightforward access to free γ‐secondary amino alcohols, which are key building blocks for a variety of pharmaceuticals and natural products, with high yields (>99%) and excellent enantioselectivities (up to 99% ee) in all cases.
Robust L2−L∞ Filtering for Stochastic Systems with Discrete and Distributed Time‐Varying Delays
Authors: Li Lin , Jia Yingmin
Published: October 2011

This paper is devoted to the problem of robust L2–L∞ filtering for a class of stochastic systems with both discrete and distributed time‐varying delays. The objective is to design a full‐order filter such that the resulting filtering error system is stochastically asymptotically stable with a prescribed L2–L∞ performance satisfied. Delay‐dependent sufficient condition for the existence of the filter is obtained in terms of linear matrix inequalities (LMIs). And the filter design method is proposed, while the explicit expression for the desired filter is also given. Numerical examples are included to illustrate the benefit and the effectiveness of the proposed method.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Click Assembly of Dye‐Functionalized Octasilsesquioxanes for Highly Efficient and Photostable Photonic Systems
Authors: Pérez‐Ojeda M. Eugenia , Trastoy Beatriz , López‐Arbeloa Íñigo , Bañuelos Jorge , Costela Ángel , García‐Moreno Inmaculada , Chiara Jose Luis
Published: October 2011

New hybrid organic–inorganic dyes based on an azide‐functionalized cubic octasilsesquioxane (POSS) as the inorganic part and a 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BDP) chromophore as the organic component have been synthesized by copper(I)‐catalyzed 1,3‐dipolar cycloaddition of azides to alkynes. We have studied the effects of the linkage group of BDP to the POSS unit and the degree of functionalization of this inorganic core on the ensuing optical properties by comparison with model dyes. The high fluorescence of the BDP dye is preserved in spite of the linked chain at its meso position, even after attaching one BDP moiety to the POSS core. The laser action of the new dyes has been analyzed under transversal pumping at 532 nm in both the liquid phase and when incorporated into solid polymeric matrices. The monosubstituted new hybrid dye exhibits high lasing efficiency of up to 56 % with high photostability, with its laser output remaining at the initial value after 4×105 pump pulses in the same position of the sample at a repetition rate of 30 Hz. However, functionalization of the POSS core with eight fluorophores leads to dye aggregation, as quantum mechanical simulation has revealed, worsening the optical properties and extinguishing the laser action. The new hybrid systems based on dye‐linked POSS nanoparticles open up the possibility of using these new photonic materials as alternative sources for optoelectronic devices, competing with dendronized or grafted polymers.
Small Pd Nanoparticles Supported in Large Pores of Mesocellular Foam: An Excellent Catalyst for Racemization of Amines
Authors: Shakeri Mozaffar , Tai Cheuk‐wai , Göthelid Emmanuelle , Oscarsson Sven , Bäckvall Jan‐E.
Published: October 2011

Highly dispersed palladium nanoparticles (1–2 nm) supported in large‐pore mesocellular foam (MCF; 29 nm) were synthesized. The Pd‐nanocatalyst/MCF system was characterized by transmission electron microscopy (TEM), powder X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The performance of the Pd nanocatalyst obtained was examined for amine racemization. The Pd nanocatalyst showed higher activity and selectivity toward racemization of (S)‐1‐phenylethyl amine than any other amine racemization catalyst reported so far and it could be reused several times. Our data from TEM and XRD suggest a restructuring of the Pd nanocatalyst from amorphous to crystalline and an increase in Pd nanocatalyst size during the racemization reaction. This led to an unexpected increase of activity after the first use. The Pd nanocatalyst obtained can be integrated with other resolving processes of racemic organic compounds to increase the yield of chiral organic products.
Highly Efficient and Diastereoselective Gold(I)‐Catalyzed Synthesis of Tertiary Amines from Secondary Amines and Alkynes: Substrate Scope and Mechanistic Insights
Authors: Liu Xin‐Yuan , Guo Zhen , Dong Sijia S. , Li Xiao‐Hua , Che Chi‐Ming
Published: October 2011

An efficient method for the synthesis of tertiary amines through a gold(I)‐catalyzed tandem reaction of alkynes with secondary amines has been developed. In the presence of ethyl Hantzsch ester and [{(tBu)2(o‐biphenyl)P}AuCl]/AgBF4 (2 mol %), a variety of secondary amines bearing electron‐deficient and electron‐rich substituents and a wide range of alkynes, including terminal and internal aryl alkynes, aliphatic alkynes, and electron‐deficient alkynes, underwent a tandem reaction to afford the corresponding tertiary amines in up to 99 % yield. For indolines bearing a preexisting chiral center, their reactions with alkynes in the presence of ethyl Hantzsch ester catalyzed by [{(tBu)2(o‐biphenyl)P}AuCl]/AgBF4 (2 mol %) afforded tertiary amines in excellent yields and with good to excellent diastereoselectivity. All of these organic transformations can be conducted as a one‐pot reaction from simple and readily available starting materials without the need of isolation of air/moisture‐sensitive enamine intermediates, and under mild reaction conditions (mostly room temperature and mild reducing agents). Mechanistic studies by NMR spectroscopy, ESI‐MS, isotope labeling studies, and DFT calculations on this gold(I)‐catalyzed tandem reaction reveal that the first step involving a monomeric cationic gold(I)–alkyne intermediate is more likely than a gold(I)–amine intermediate, a three‐coordinate gold(I) intermediate, or a dinuclear gold(I)–alkyne intermediate. These studies also support the proposed reaction pathway, which involves a gold(I)‐coordinated enamine complex as a key intermediate for the subsequent transfer hydrogenation with a hydride source, and reveal the intrinsic stereospecific nature of these transformations observed in the experiments.
ChemInform Abstract: Crystal Structure of LiLnW2O8 (Ln: Lanthanides and Y): An X‐Ray Powder Diffraction Study.
Authors: Postema J. M. , Fu W. T. , Ijdo D. J. W.
Published: October 2011

The title compounds crystallize with the scheelite‐type structure in the space group I41/a for Ln: La—Gd and with the wolframite structure in the space group P2/n for Ln: Dy—Lu and Y.
ChemInform Abstract: Photocatalytic Activities of Various Pentavalent Bismuthates under Visible Light Irradiation.
Authors: Takei Takahiro , Haramoto Rie , Dong Qiang , Kumada Nobuhiro , Yonesaki Yoshinori , Kinomura Nobukazu , Mano Takayuki , Nishimoto Shunsuke , Kameshima Yoshikazu , Miyake Michihiro
Published: October 2011

Alkali and alkaline earth pentavalent bismuthates LiBiO3, NaBiO3, SrBi2O6, and BaBi2O6 possess high photocatalytic activity for decomposition of methylene blue and phenol under visible light.
ChemInform Abstract: Structure and Properties of a Novel Cobaltate La0.30CoO2.
Authors: Knizek K. , Hejtmanek J. , Marysko M. , Santava E. , Jirak Z. , Bursik J. , Kirakci K. , Beran P.
Published: October 2011

The title compound is prepared by solid state ion‐exchange of NaCoO2 with 10% excess La(NO3)3 (300 °C, 2 d).
ChemInform Abstract: Alkylation of 1,3‐Dicarbonyl Compounds with Benzylic and Propargylic Alcohols Using Ir—Sn Bimetallic Catalyst: Synthesis of Fully Decorated Furans and Pyrroles.
Authors: Chatterjee Paresh Nath , Roy Sujit
Published: October 2011

In addition to the benzylation and propargylation of 1,3‐dicarbonyl compounds, hydroxycoumarin (XXI) is alkylated at the 3‐position.
ChemInform Abstract: Gold Catalysis: Domino Reaction of En‐Diynes to Highly Substituted Phenols.
Authors: Hashmi A. Stephen K. , Haeffner Tobias , Rudolph Matthias , Rominger Frank
Published: October 2011

Precursors bearing a 2‐alkynylallyl alcohol moiety tethered to an additional alkyne are prepared by Sonogashira coupling.
ChemInform Abstract: Hydroxylation of Nitro‐(pentafluorosulfanyl)benzenes via Vicarious Nucleophilic Substitution of Hydrogen.
Authors: Beier Petr , Pastyrikova Tereza
Published: October 2011

Treatment of the title compounds (I) with cumyl hydroperoxide in the presence of tBuOH in liquid ammonia gives the corresponding nitrophenols which can be further converted to aminophenols.
ChemInform Abstract: Highly Enantio‐ and Diastereoselective Synthesis of β‐Methyl‐γ‐monofluoromethyl‐Substituted Alcohols.
Authors: Yang Wenguo , Wei Xinle , Pan Yuanhang , Lee Richmond , Zhu Bo , Liu Hongjun , Yan Lin , Huang Kuo‐Wei , Jiang Zhiyong , Tan Choon‐Hong
Published: October 2011

The title alcohols are prepared via allylic alkylation of bis(sulfone) (II) with Morita—Baylis—Hillman carbonates (I) in the presence of a cinchona‐derived catalyst.
ChemInform Abstract: A Highly Active and Recyclable Catalyst: Phosphine Dendrimer‐Stabilized Nickel Nanoparticles for the Suzuki Coupling Reaction.
Authors: Wu Lei , Ling Jie , Wu Zong‐Quan
Published: October 2011

The catalyst exhibits higher efficiency (60 °C, maximum TON 99.000) than the Pd analogue (110 °C.
ChemInform Abstract: Synthesis of Functionalized 2‐Arylthiophenes with Triarylbismuths as Atom‐Efficient Multicoupling Organometallic Nucleophiles under Palladium Catalysis.
Authors: Rao Maddali L. N. , Banerjee Debasis , Dhanorkar Ritesh J.
Published: October 2011

The arylation can be easily performed under conditions A) in the presence of 0.3 equiv.
ChemInform Abstract: Synthesis of a New Fluorescent Small Molecule Probe and Its Use for in vivo Lipid Imaging.
Authors: Lee Jae Hong , So Ju‐Hoon , Jeon Jong Hyun , Choi Eun Bok , Lee Yu‐Ri , Chang Young‐Tae , Kim Cheol‐Hee , Bae Myung Ae , Ahn Jin Hee
Published: October 2011

The compound (III), named LipidGreen, stains lipid droplets in 3T3L1 pre‐adipocyte cell lines and fat deposits in zebrafish.
ChemInform Abstract: A Regioselective and High‐Yielding Method for Formaldehyde Inclusion in the 3CC Groebke—Blackburn—Bienayme Reaction: One‐Step Access to 3‐Aminoimidazoazines.
Authors: Sharma Anuj , Li Hong‐yu
Published: October 2011

Optimized conditions including glyoxylic acid as a formaldehyde equivalent are developed.
ChemInform Abstract: Silver‐Catalyzed Synthesis of Disubstituted Isoxazoles by Cyclization of Alkynyl Oxime Ethers.
Authors: Ueda Masafumi , Ikeda Yuki , Sato Aoi , Ito Yuta , Kakiuchi Maiko , Shono Hiroko , Miyoshi Tetsuya , Naito Takeaki , Miyata Okiko
Published: October 2011

Under weakly acidic conditions using phenol as proton source, AgBF4 is found to be the most optimal catalyst among five tested metal catalysts for the title reaction in THF.
ChemInform Abstract: A New Strategy for the Synthesis of Substituted Dihydropyrones and Tetrahydropyrones via Palladium‐Catalyzed Coupling of Thioesters.
Authors: Fuwa Haruhiko , Mizunuma Kana , Matsukida Seiji , Sasaki Makoto
Published: October 2011

The method consists of a Pd‐catalyzed coupling of thioesters with terminal alkynes, O‐deprotection and AgOTf‐mediated oxa‐conjugate cyclization of β‐hydroxyenones leading to the 2,6‐substituted dihydropyrones.
ChemInform Abstract: Synthesis and Biological Evaluation of a Novel Series of 1,3‐Dicoumarinyl‐5‐aryl‐2‐pyrazolines.
Authors: Cacic Milan , Molnar Maja , Strelec Ivica
Published: October 2011

The compounds (II) and (III) are screened for their antioxidant and iron‐chelating activity.
ChemInform Abstract: Phosphine‐Catalyzed [3 + 2] Cyclizations: Applications to the Enantioselective Synthesis of Cyclopentene‐Fused Chromanones and Dihydroquinolinones.
Authors: Neel Mathilde , Gouin Jerome , Voituriez Arnaud , Marinetti Angela
Published: October 2011

Two synthetic approaches to the title compounds are demonstrated based on (S,S)‐FerroPHANE‐promoted cyclization.
ChemInform Abstract: Chiral Thiourea‐Catalyzed Asymmetric Michael Addition of β‐Oxo Phosphonate to Nitro Olefins: Convenient Synthesis of Optically Active β‐Oxo Phosphonates.
Authors: Hu Kuang , Liu Tao , Lu A. D. , Liu Yunfeng , Wang Youming , Wu Guiping , Zhou Zhenghong , Tang Chuchi
Published: October 2011

In the presence of cinchonine‐based bifunctional thiourea catalyst CTU, α‐substituted β‐oxo phosphonates are formed.
ChemInform Abstract: Studies Directed Toward Synthesis of the Structure Proposed for Stereocalpin A.
Authors: Huang Yixian , Wu Yikang
Published: October 2011

The aldol subunit of the target depsipeptide (V) is constructed efficiently using the Evans asymmetric aldol reaction, with the absolute configuration of all stereogenic centers established without any ambiguity.
ChemInform Abstract: Synthesis of Triazole‐Linked Amino Acid‐Aryl C‐Glycoside Hybrids via Click Chemistry as Novel PTP1B Inhibitors.
Authors: Wang Jia , He Xiaopeng , Gao Lixin , Sheng Li , Shi Xiaoxin , Li Jia , Chen Guorong
Published: October 2011

Triazolyl phenylalanine and tyrosine‐aryl C‐glycoside hybrids are readily synthesized in high yield via microwave‐assisted Cu(I)‐catalyzed azide‐alkyne 1,3‐dipolar cycloaddition.
ChemInform Abstract: A Short Formal Total Synthesis of Strychnine with a Samarium Diiodide Induced Cascade Reaction as the Key Step.
Authors: Beemelmanns Christine , Reissig Hans‐Ulrich
Published: October 2011

Treatment of indole substrates (I) according to A) produces mainly the tetracyclic heterocycles (II) and (IV) in a diastereomerically pure form as scaffolds of the Strychnos alkaloids.
ChemInform Abstract: Synthetic Study of Carbocyclic Core of Cortistatin A, an anti‐Angiogenic Steroidal Alkaloid from Marine Sponge.
Authors: Kotoku Naoyuki , Sumii Yuji , Hayashi Takeshi , Kobayashi Motomasa
Published: October 2011

The synthesis of the carbocyclic core of cortistatin A (II)/(III) is achieved through a 7‐endo intramolecular Heck reaction.
ChemInform Abstract: A Near‐Infrared Fluorescent Probe for Detecting Copper(II) with High Selectivity and Sensitivity and Its Biological Imaging Applications.
Authors: Li Ping , Duan Xia , Chen Zhenzhen , Liu Ying , Xie Ting , Fang Libo , Li Xiaorui , Yin Miao , Tang Bo
Published: October 2011

The title compound (I) detects Cu2+ with high sensitivity and selectivity and its fluorescence increases ten‐fold during the reversible binding process.
ChemInform Abstract: Molecular Organic‐Inorganic Layer Compounds as Electronic Functional Materials
Authors: Day Peter
Published: October 2011

Review: 23 refs.
ChemInform Abstract: Poisoning of Zeolite Catalysts
Authors: Guisnet M.
Published: October 2011

Review: 39 refs.
ChemInform Abstract: Chemistry and Biological Activity of Platinum Amidine Complexes
Authors: Michelin Rino A. , Sgarbossa Paolo , Mazzega Sbovata Silvia , Gandin Valentina , Marzano Cristina , Bertani Roberta
Published: October 2011

Review: 106 refs.
ChemInform Abstract: Allenes as Building Blocks in Heterocyclic Chemistry
Authors: Pinho e Melo Teresa M. V. D.
Published: October 2011

Review: 84 refs.
ChemInform Abstract: Absorption Tuning of the Green Fluorescent Protein Chromophore: Synthesis and Studies of Model Compounds
Authors: Broensted Nielsen Mogens , Andersen Lars H. , Rocha‐Rinza Tomas
Published: October 2011

Review: 25 refs.
ChemInform Abstract: Development of New N,N‐Ligands for the Enantioselective Copper(II)‐Catalyzed Henry Reaction
Authors: Blay Gonzalo , Hernandez‐Olmos Victor , Pedro Jose R.
Published: October 2011

Review: ca. 100 refs.
ChemInform Abstract: Generation of Novel Nucleases with Extended Specificity by Rational and Combinatorial Strategies
Authors: Pingoud Alfred , Wende Wolfgang
Published: October 2011

Review: 88 refs.
ChemInform Abstract: Recent Advances in Amine Synthesis by Catalytic Hydroaminomethylation of Alkenes
Authors: Crozet Delphine , Urrutigoity Martine , Kalck Philippe
Published: October 2011

Review: more than 100 refs.
ChemInform Abstract: Stereoselective Acetate Aldol Reactions from Metal Enolates
Authors: Ariza Xavier , Garcia Jordi , Romea Pedro , Urpi Felix
Published: October 2011

Review: ca. 150 refs.
ChemInform Abstract: Regioselective Reductive Openings of 4,6‐Benzylidene Acetals: Synthetic and Mechanistic Aspects
Authors: Ohlin Markus , Johnsson Richard , Ellervik Ulf
Published: October 2011

Review: 67 refs.
ChemInform Abstract: Oxidation of Thiourea and Substituted Thioureas
Authors: Sahu Sandhyamayee , Sahoo Prangya Rani , Patel Sabita , Mishra B. K.
Published: October 2011

Review: 146 refs.
ChemInform Abstract: Carbocations
Authors: McClelland R. A.
Published: October 2011

Review: 140 refs.
ChemInform Abstract: Hierarchical Assembly of Micro‐/Nano‐Building Blocks: Bioinspired Rigid Structural Functional Materials
Authors: Yao Hong‐Bin , Fang Hai‐Yu , Wang Xiao‐Han , Yu Shu‐Hong
Published: October 2011

Review: 177 refs.
ChemInform Abstract: Natural Products Containing a Diazo Group
Authors: Nawrat Christopher C. , Moody Christopher J.
Published: October 2011

Review: 113 refs.
ChemInform Abstract: Hair Analysis as a Biomonitor for Toxicology, Disease and Health Status
Authors: Kempson Ivan M. , Lombi Enzo
Published: October 2011

Review: 298 refs.
ChemInform Abstract: Injectable Hydrogels as Biomaterials
Authors: Nair Lakshmi S. , Laurencin Cato T. , Tandon Mayank
Published: October 2011

Review: 110 refs.
Enantioselective degradation of warfarin in soils
Authors: Lao Wenjian , Gan Jay
Published: October 2011

Environmental enantioselectivity information is important to fate assessment of chiral contaminants. Warfarin, a rodenticide and prescription medicine, is a chiral chemical but used in racemic form. Little is known about its enantioselective behavior in the environment. In this study, enantioselective degradation of warfarin in a turfgrass and a groundcover soils was examined in aerobic and ambient temperature conditions. An enantioselective analytical method was established using a novel triproline chiral stationary phase in high performance liquid chromatography. Unusual peak profile patterns, i.e., first peak (S(−)) broadening/second peak (R(+)) compression with hexane (0.1%TFA)/2‐propanol (92/8, v/v) mobile phase, and first peak compression/second peak broadening with the (96/4, v/v) mobile phase, were observed in enantioseparation. This unique tunable peak property was leveraged in evaluating warfarin enantioselective degradation in two types of soil. Warfarin was extracted in high recovery from soil using methylene chloride after an aqueous phase basic‐acidic conversion. No apparent degradation of warfarin was observed in the sterile turfgrass and groundcover soils during the 28 days incubation, while it showed quick degradation (half‐life <7 days) in the nonsterile soils after a short lag period, suggesting warfarin degradation in the soils was mainly caused by micro‐organisms. Limited enantioselectivity was found in the both soils, which was the R(+) enantiomer was preferentially degraded. The half‐lives in turfgrass soil were 5.06 ± 0.13 and 5.97 ± 0.05 days, for the R(+) and the S(−) enantiomer, respectively. The corresponding values for the groundcover soil were 4.15 ± 0.11 and 4.47 ± 0.08 days. Chirality, 2011. © 2011 Wiley Periodicals, Inc.
Structural heterogeneity mediates the effect of community structure on cooperation
Authors: Xie Fengjie , Cui Wentian , Lin Jun
Published: October 2011

Emergence of cooperation in evolutionary prisoner's dilemma game strongly depends on the topology of underlying interaction network. We explore this dependence using community networks with different levels of structural heterogeneity, which are generated by a tunable upper‐bound on the total number of links that any vertex can have. We study the effect of community structure on cooperation by analyzing a finite population analogue of the evolutionary replicator dynamics. We find that structural heterogeneity mediates the effect of community structure on cooperation. In the community networks with low level of structural heterogeneity, community structure has negative effect on cooperation. However, the positive effect of community structure on cooperation appears and enhances with increasing structural heterogeneity. Our work may be helpful for understanding the complexity of cooperative behaviors in social networks. © 2011 Wiley Periodicals, Inc. Complexity, 2012
Exploring Iron‐based Multifunctional Catalysts for Fischer–Tropsch Synthesis: A Review
Authors: Abelló Sònia , Montané Daniel
Published: October 2011

The continuous increase in oil prices together with an increase in carbon dioxide concentration in the atmosphere has prompted an increased interest in the production of liquid fuels from non‐petroleum sources to ensure the continuation of our worldwide demands while maximizing CO2 utilization. In this sense, the Fischer–Tropsch (FT) technology provides a feasible option to render high value‐added hydrocarbons. Alternative sources, such as biomass or coal, offer a real possibility to realize these purposes by making use of H2‐deficient or CO2‐rich syngas feeds. The management of such feeds ideally relies on the use of iron catalysts, which exhibit the unique ability to adjust the H2/CO molar ratio to an optimum value for hydrocarbon synthesis through the water‐gas‐shift reaction. Taking advantage of the emerging attention to hybrid FT‐synthesis catalysts based on cobalt and their associated benefits, an overview of the current state of literature in the field of iron‐based multifunctional catalysts is presented. Of particular interest is the use of zeolites in combination with a FT catalyst in a one‐stage operation, herein named multifunctional, which offer key opportunities in the modification of desired product distributions and selectivity, to eventually overcome the quality limitations of the fuels prepared under intrinsic FT conditions. This review focuses on promising research activities addressing the conversion of syngas to liquid fuels mediated by iron‐based multifunctional materials, highlights their preparation and properties, and discusses their implication and challenges in the area of carbon utilization through H2/CO(+CO2) mixtures.
(NHC)Palladium Complexes from Hydroxy‐Functionalized Imidazolium Salts as Catalyst for the Microwave‐Accelerated Fluorine‐Free Hiyama Reaction
Authors: Peñafiel Itziar , Pastor Isidro M. , Yus Miguel , Esteruelas Miguel A. , Oliván Montserrat , Oñate Enrique
Published: October 2011

Palladium acetate reacts with 1‐benzyl‐3‐(2‐hydroxy‐2‐phenylethyl)‐1H‐imidazolium chloride to give the corresponding bis(carbene)palladium(II) complex 5 [(NHC)2PdCl2] by direct metalation. The X‐ray diffraction structure of the complex is reported. In the presence of NaOH solution (50 % H2O, w/w) in air and under microwave irradiation, the bis(NHC)pallalium(II) complex 5 is an active precatalyst for the Hiyama coupling of aryl halides with trialkoxy(aryl)silanes, providing biaryls and heterobiaryls. For some deactivated aryl bromides and for aryl chlorides, the corresponding cross‐coupling reactions require tetrabutylammonium bromide (TBAB) as additive. The fluoride‐free Hiyama reactions are performed with low (NHC)palladium loadings (0.1 mol‐%). The active catalyst can also be prepared in situ from Pd(OAc)2 and the corresponding imidazolium salt 4.
Steel buckling‐restrained braced frames with single and dual corner gusset connections: seismic tests and analyses
Authors: Chou Chung‐Che , Liu Jia‐Hau , Pham Dinh‐Hai
Published: October 2011

The design of a three‐story buckling‐restrained braced frame (BRBF) with a single‐diagonal sandwiched BRB and corner gusset was evaluated in cyclic tests of a one‐story, one‐bay BRBF subassembly and dynamic analyses of the frame subjected to earthquakes. The test focused on evaluating (1) the seismic performance of a sandwiched BRB installed in a frame, (2) the effects of free‐edge stiffeners and dual gusset configurations on the corner gusset behavior, (3) the frame and brace action forces in the corner gusset, and (4) the failure mode of the BRBF under the maximum considerable earthquake level. The subassembly frame performed well up to a drift of 2.5% with a maximum axial strain of 1.7% in the BRB. Without free‐edge stiffeners, the single corner gusset plate buckled at a significantly lower strength than that predicted by the specificationof American Institute of Steel Construction (2005). The buckling could be eliminated by using dual corner gusset plates similar in size to the single gusset plate. At low drifts, the frame action force on the corner gusset was of the same magnitude as the brace force. At high drifts, however, the frame action force significantly increased and caused weld fractures at column‐to‐gusset edges. Nonlinear time history analyses were performed on the three‐story BRBF to obtain seismic demands under both design and maximum considerable levels of earthquake loading. The analytical results confirmed that the BRB and corner gusset plate achieved peak drift under cyclic loading test. Copyright © 2011 John Wiley & Sons, Ltd.
Detecting nanoparticulate silver using single-particle inductively coupled plasma–mass spectrometry
Authors: Mitrano Denise M. , Lesher Emily K. , Bednar Anthony , Monserud Jon , Higgins Christopher P. , Ranville James F.
Published: October 2011

The environmental prevalence of engineered nanomaterials, particularly nanoparticulate silver (AgNP), is expected to increase substantially. The ubiquitous use of commercial products containing AgNP may result in their release to the environment, and the potential for ecological effects is unknown. Detecting engineered nanomaterials is one of the greatest challenges in quantifying their risks. Thus, it is imperative to develop techniques capable of measuring and characterizing exposures, while dealing with the innate difficulties of nanomaterial detection in environmental samples, such as low-engineered nanomaterial concentrations, aggregation, and complex matrices. Here the authors demonstrate the use of inductively coupled plasma–mass spectrometry, operated in a single-particle counting mode (SP-ICP-MS), to detect and quantify AgNP. In the present study, two AgNP products were measured by SP-ICP-MS, including one of precisely manufactured size and shape, as well as a commercial AgNP-containing health food product. Serial dilutions, filtration, and acidification were applied to confirm that the method detected particles. Differentiation of dissolved and particulate silver (Ag) is a feature of the technique. Analysis of two wastewater samples demonstrated the applicability of SP-ICP-MS at nanograms per liter Ag concentrations. In this pilot study, AgNP was found at 100 to 200 ng/L in the presence of 50 to 500 ng/L dissolved Ag. The method provides the analytical capability to monitor Ag and other metal and metal oxide nanoparticles in fate, transport, stability, and toxicity studies using a commonly available laboratory instrument. Rapid throughput and element specificity are additional benefits of SP-ICP-MS as a measurement tool for metal and metal oxide engineered nanoparticles. Environ. Toxicol. Chem. 2012;31:115–121. © 2011 SETAC
Two‐dimensional imaging of spontaneous ultra‐weak photon emission from the human skin: role of reactive oxygen species
Authors: Prasad Ankush , Pospišil Pavel
Published: October 2011

In the human skin, reactive oxygen species (ROS) produced continuously during oxidative metabolic processes (cellular respiration, oxidative burst) are essential for various cellular processes such as defense against infection, cellular signaling and apoptosis. On the other hand, when the formation of ROS exceeds a capacity of the non‐enzymatic and the enzymatic antioxidant defense system, ROS cause the damage to the human skin known to initiate premature skin aging and skin cancer. In this study, two‐dimensional spontaneous ultra‐weak photon emission from the human skin has been measured using a highly sensitive charged coupled device (CCD) camera. It is demonstrated here that two‐dimensional ultra‐weak photon emission from the human skin increases with the topical application of exogenous ROS in the following order: hydrogen peroxide (H2O2) < superoxide anion radical (O2•–) < hydroxyl radical (HO•). We propose here that the two‐dimensional ultra‐weak photon emission can be used as a non‐invasive tool for the spatial and temporal monitoring of oxidative stress in the human skin. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tandem mass spectrometric analysis of novel diquaternary ammonium gemini surfactants and their bromide adducts in electrospray‐positive ion mode ionization
Authors: Buse Joshua , Badea Ildiko , Verrall Ronald E. , El‐Aneed Anas
Published: October 2011

Gemini surfactants are cationic lipids which are utilized for both in vitro and in vivo gene delivery. Structurally, they are comprised of two hydrophobic tail regions with polar head termini that are attached to one another through a spacer region. Structural elucidation and characterization of 29 novel diquaternary ammonium gemini surfactant molecules were achieved using a quadrupole time‐of‐flight mass spectrometer (QqToF‐MS) and a quadrupole‐hexapole‐quadrupole mass spectrometer (QhQ‐MS). The tested compounds were categorized into four distinct structural families based upon the composition of the spacer region. Single stage (MS), tandem stage (MS/MS) and quasimulti‐stage (quasi MS3) mass spectrometric analysis allowed for confirmation of each gemini surfactant's molecular composition and structure through the identification of common and unique product ions. Identification of similarities in the gemini surfactants’ fragmentation behaviour resulted in the production of a universal fragmentation pathway that can assist in the future MS/MS analysis of novel quaternary ammonium gemini surfactants, with unique product ions being indicative of specific structural elements. Furthermore, evidence for the association of agemini surfactant with bromine counter ion was confirmed during MS analysis of tested gemini surfactants regardless of their chemical composition; previously, evidence for bromine and gemini surfactant association was only observed with compounds bearing short alkyl spacer regions. MS/MS analysis of the bromine adducts was also confirmatory to the molecular structure.Understanding the ionization and fragmentation behaviour of gemini surfactants, including bromine adducts, will allow for future qualitative and quantitative identification of these novel drug delivery agents within biological samples. Copyright © 2011 John Wiley & Sons, Ltd.
Deliberate manipulation of the surface hydrophobicity of an adsorbent for an efficient purification of a giant molecule with multiple subunits
Authors: Zhao Lan , Liu Yongdong , Huang Yongdong , Li Xiunan , Wang Yinjue , Li Yan , Ma Guanghui , Su Zhiguo
Published: October 2011

Hydrophobic interaction chromatography (HIC) is often an inevitable step for a satisfying purification in giant vaccine molecules production. But great mass and activity loss associated with poor purity often occur simultaneously. In this paper, high purity and high bioactivity recovery for the HIC process of hepatitis B surface antigen (rHBsAg) purification were achieved through manipulation of surface hydrophobicity of the adsorbent. Spacer arm length and ligand density were regulated, respectively, through which the interaction between the vaccine and the adsorbent was manipulated deliberately. It was found even in a narrow scope, varying spacer arm length and ligand density resulted in purification factor changing from 1 to 96.5, and rHBsAg recovery from 3 to 91%. The optimal purification performance was achieved when the spacer arm was C8 and the ligand density was 9.2 μmol/g suction‐dried wet gel with an average distance of ligands of 3.6 nm. This deliberate regulation strategy represents a new approach of improving purification of giant multi‐subunit proteins.
Rapid simultaneous determination of multiple pesticide residues in traditional Chinese medicines using programmed temperature vaporizer injection–fast gas chromatography coupled with mass spectrometry
Authors: Du Gang , Song Yuelin , Wang Yitao
Published: October 2011

A fast gas chromatography coupled with mass spectrometry (GC‐MS) using large volume injection with programmed temperature vaporizer in solvent vent mode (PTV‐LVI‐SV) was developed for the trace determination of multiple pesticide residues in traditional Chinese medicines (TCMs). Experimental conditions of PTV‐LVI‐SV injection were optimized by central composite design. The optimized result was that initial temperature was held at 40°C for 39 s, vent flow rate was set at 45 mL/min and vent pressure was held at 0 psi for 36 s, injection volume was 10 μL. Furthermore, the quick and effective QuEChERS (quick, easy, cheap, effective, rugged and safe) method was performed to extract and purify pesticide residues in TCMs. The prepared samples were analyzed with GC‐MS in the selected ion monitoring mode (SIM). The lowest LOD was 4 μg/kg for some pesticides. The recoveries were checked by spiking samples with pesticides at 25, 50 and 250 μg/kg. The average recoveries of most pesticides were from 80 to 118%. The result indicated that QuEChERS and PTV‐LVI‐SV GC‐MS method was a rapid and sensitive analysis technique for the determination of multiple pesticide residues in TCMs.
A FRAMEWORK FOR NATIONAL ASSESSMENT OF LAND DEGRADATION IN THE DRYLANDS: A CASE STUDY OF SOMALIA
Authors: Omuto C. T. , Balint Z. , Alim M. S.
Published: October 2011

Land degradation is a gradual, negative environmental process that is accelerated by human activities. Its gradual nature allows degradation to proceed unnoticed, thus reducing the likelihood of appropriate and timely control action. Presently, there are few practical frameworks to help countries design national strategies and policies for its control. The study presented here developed a framework for the national assessment of land degradation. This framework is envisaged to support governments in formulating policies on land degradation. It uses time‐series remote sensing data to identify the rate and extent of land degradation, local experts to identify prevalent degradation types and drivers of the degradation and field observations to validate the overall assessment. Its simplicity, use of freely downloadable input data and self‐triangulation of the assessment methods make it suitable for rapid assessment of land degradation on a national scale. It was tested in Somalia, where it exhibited accuracy greater than 60 per cent when assessing land degradation. This framework is relevant for designing national strategies and policies that address land degradation and provides an opportunity for accurate identification of areas to target with comprehensive local assessment. Testing of the framework in Somalia showed that about one‐third of the country was degraded because of loss of vegetation cover, topsoil loss and to the decline of soil moisture. Overgrazing, excessive tree cutting and poor agronomic practices in agricultural areas were identified as the primary drivers of the country's land degradation. These drivers are encouraged by the prevailing communal land tenure practices, poor governance and civil war. Copyright © 2011 John Wiley & Sons, Ltd.
Europäische Bildverarbeitungsindustrie wieder auf Wachstumskurs
Authors: Breyer Andreas
Published: October 2011

Schneller als sogar von den Unternehmen selbst erwartet hat sich die Bildverarbeitungsindustrie in Europa von den Folgen der globalen Finanz‐ und Wirtschaftkrise erholt. Dies zeigt die aktuelle EMVA‐Studie „European Vision Technology Market Statistics 2011”︁. Erstmals enthält die Studie einen Branchenreport über die dynamische Bildverarbeitungsbranche in Frankreich.
Poly(L‐lactic acid) metal organic framework composites: optical, thermal and mechanical properties
Authors: Elangovan Dhayalan , Yuzay Isinay E , Selke Susan E M , Auras Rafael
Published: October 2011

Biodegradable composites based on poly(L‐lactic acid) (PLLA) and metal organic frameworks (MOFs) were developed. PLLA without and with the addition of 1, 3 and 5 wt% MOFs was melt compounded in a microextruder. The optical, physical, thermal, mechanical and thermomechanical properties of the composites were evaluated. The Fourier transform infrared, ultraviolet and colorimetric studies showed selected absorption at particular wavelengths due to the presence of copper and benzene belonging to the MOFs. The dynamic mechanical analysis results revealed that the heat deflection temperature, storage modulus and loss modulus of the PLLA–MOF composites did not significantly change compared with the neat PLLA samples. However, a significant decrease in the brittleness of the PLLA–MOF composite was found as evidenced by an increase of 15% in Izod impact strength and 170% in elongation at break. Overall, the brittleness of the PLLA–MOF composite sample decreased as the amount of MOF in the PLLA increased. Copyright © 2011 Society of Chemical Industry
Basis set dependence of phosphate frequencies in density functional theory calculations
Authors: Rudbeck Maria
Published: October 2011

The addition of extravalence, polarization and diffuse functions, were studied in order to conclude how they affect the PO stretching frequencies of several biological relevant phosphate molecules. The results show that the polarization and the diffuse functions have opposite effects on the frequencies: the polarization functions downshift while the diffuse functions upshift the frequencies. The effect of the valence functions was more difficult to interpret. The effect of the conductor‐like screening model (CPCM)‐continuum model was also studied. The results show that the CPCM‐continuum model has a substantial effect on the frequencies for these small molecules. The continuum model's efficiency is mainly due to its effect on the geometries and not on the frequencies. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
The use of pattern participants relationships for integrating patterns: a controlled experiment
Authors: Kamal Ahmad Waqas , Avgeriou Paris , Zdun Uwe
Published: October 2011

Architectural patterns are often applied in combination with related patterns within software architectures. The relationships among architectural patterns must be considered when applying a combination of patterns into a system; for example the way the Model‐View‐Controller uses the Observer pattern to implement the change propagation mechanism needs to be carefully designed. However, effective integration of architectural patterns within software architectures remains a challenging task. This is because the integration of any two architectural patterns can take several forms. Furthermore, existing pattern languages define generic and abstract relationships between architectural patterns without going into detail about associations among the participants of architectural patterns. In this paper, we propose to address the pattern integration issue by discovering and defining a set of pattern participants relationships that serve the purpose of effectively integrating architectural patterns. Our findings are validated through a controlled experiment, which provides significant evidence that the proposed relationships support inexperienced designers in integrating patterns. Copyright © 2011 John Wiley & Sons, Ltd.