bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Fabrication of Size‐Tunable Silica Nanotubes Using a Reverse‐ Microemulsion‐Mediated Sol–Gel Method
Authors: Jang J. , Yoon H.
Published: May 2004

Size‐tunable silica nanotubes have been fabricated using a novel reverse‐microemulsion‐mediated sol–gel method (see Figure). This facile approach is adaptable to large‐scale fabrication, and the diameter of silica nanotubes is tunable through the use of different apolar solvents. The photoluminescence spectrum of the nanotubes displays three emission bands, including a stable and strong blue light emission at 435 nm.
Electronic Structure, Isomerism, and Chemical Bonding in B7‐ and B7
Authors: Alexandrova Anastassia N. , Boldyrev Alexander I. , Zhai Hua‐Jin , Wang Lai‐Sheng
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Phase Equilibria in the CuInSe2—GeSe2 and CuInSe2—Cu2GeSe3 Sections of the Quaternary Cu2Se—In2Se3—GeSe2 System.
Authors: Vakulovich A. P. , Olekseyuk I. D.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Oxygen Storage Mechanism Based on Redox of Sulfur in Lanthanum Oxysulfate/Oxysulfide.
Authors: Machida Masato , Kawamura Kiyotaka , Ito Kazuhiro
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Directed Evolution of Noble‐Metal‐Free Catalysts for the Oxidation of CO at Room Temperature.
Authors: Saalfrank Jens W. , Maier Wilhelm F.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
The Preparation and X‐Ray Crystal Structure of [(AgI2)n]×nMF6 (M: Sb, As): Diiodine Acting as a Donor in the Planar Polymeric [(AgI2)n]n+.
Authors: Cameron T. Stanley , Passmore Jack , Wang Xinping
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
[Ag6(PMo10V2O40)] (CH3COO)×8H2O: A 3D Macrocationic Polyoxometallic Keggin Complex.
Authors: Liu Feng‐Xian , Marchal‐Roch Catherine , Bouchard Philippe , Marrot Jerome , Simonato Jean‐Pierre , Herve Gilbert , Secheresse Francis
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Generation of Strong, Homochiral Bases by Electrochemical Reduction of Phenazine Derivatives.
Authors: Alonso A. Mateo , Horcajada Roberto , Groombridge Helen J. , Mandalia Reshma , Motevalli Majid , Utley James H. P. , Wyatt Peter B.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Enantioselective Friedel—Crafts Reaction of Indoles with Arylidene Malonates Catalyzed by iPr‐Bisoxazoline—Cu(OTf)2.
Authors: Zhou Jian , Tang Yong
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
4,4′‐ and 5,5′‐DiamBINAP as a Hydrosoluble Chiral Ligand: Syntheses and Use in Ru(II) Asymmetric Biphasic Catalytic Hydrogenation.
Authors: Berthod Mikael , Saluzzo Christine , Mignani Gerard , Lemaire Marc
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Trimethylaluminum‐Promoted Rearrangements of Unsaturated Sugars into Cyclohexanes.
Authors: Jia Cai , Pearce Alan J. , Bleriot Yves , Zhang Yongmin , Zhang Li‐He , Sollogoub Matthieu , Sinay Pierre
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Scope of Palladium‐Catalyzed Alkylative Ring Opening.
Authors: Lautens Mark , Hiebert Sheldon
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Poly(ethylene glycol)‐Supported TEMPO: An Efficient, Recoverable Metal‐Free Catalyst for the Selective Oxidation of Alcohols.
Authors: Pozzi Gianluca , Cavazzini Marco , Quici Silvio , Benaglia Maurizio , Dell'Anna Gianmaria
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Recyclable 2nd Generation Ionic Liquids as Green Solvents for the Oxidation of Alcohols with Hypervalent Iodine Reagents.
Authors: Yadav J. S. , Reddy B. V. S. , Basak A. K. , Narsaiah A. Venkat
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
A Selective Conversion of Sulfides to Sulfoxides in 3‐Fluorophenol.
Authors: Xu Wei Liang , Li Yun Zheng , Zhang Qing Shan , Zhu He Sun
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
A Practical Oxidative Method for the Cleavage of Hydrazide N—N Bonds.
Authors: Fernandez Rosario , Ferrete Ana , Llera Jose M. , Magriz Antonio , Martin‐Zamora Eloisa , Diez Elena , Lassaletta Jose M.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Heck‐Type Arylation of 2‐Cycloalken‐1‐ones with Arylpalladium Intermediates Formed by Decarboxylative Palladation and by Aryl Iodide Insertion.
Authors: Tanaka Daisuke , Myers Andrew G.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Catalytic Activity of a Poly(N,N‐dialkylcarbodiimide)/Palladium Nanoparticle Composite: A Case in the Suzuki Coupling Reaction Using Microwave and Conventional Heating.
Authors: Liu Yubiao , Khemtong Chalermchai , Hu Jun
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Al(HSO4)3 as an Efficient Catalyst for the Acetylation of Alcohols in Solution and Under Solvent Free Conditions.
Authors: Shirini Farhad , Zolfigol Mohammad A. , Abedini Masoumeh
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Synthesis of Cyclopentenones with Benzylic α‐Quaternary Carbon Stereogenic Centers from Furans.
Authors: Csaky Aurelio G. , Mba Myriam , Plumet Joaquin
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
A Convenient Synthesis of Novel N′‐tert‐Butyl‐N′‐Substituted Benzoyl‐N‐(Substituted Phenyl)aminocarbonylhydrazines and Their Derivatives.
Authors: Wang Qingmin , Huang Runqiu
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of β‐Lactams and β‐Aminoesters via High Intensity Ultrasound‐Promoted Reformatsky Reactions.
Authors: Ross Nathan A. , MacGregor Robert R. , Bartsch Richard A.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Synthesis of meso‐Tetraarylporphyrins Using CF3SO2Cl under Aerobic Oxidation.
Authors: Sharghi Hashem , Nejad Alireza Hassani
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Catalytic C—H Functionalization Driven by CO as a Stoichiometric Reductant: Application to Carbazole Synthesis.
Authors: Smitrovich Jacqueline H. , Davies Ian W.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of β‐Tosylethylhydrazine and Its Use in Preparation of N‐Protected Pyrazoles and 5‐Aminopyrazoles.
Authors: Dastrup David M. , Yap Amy H. , Weinreb Steven M. , Henry James R. , Lechleiter Andrew J.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
LiClO4‐Activated Stereo‐ and Regioselective Alkylation of Aldehydes.
Authors: Markert M. , Buchem I. , Krueger H. , Mahrwald R.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
A Novel Route to Substituted 3‐Methylidenechroman‐2‐ones and 3‐Methylchromen‐2‐ones.
Authors: Janecki Tomasz , Wasek Tomasz
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
A Simple and Efficient Method for the Preparation of Heterocyclic N‐Oxide.
Authors: Zhong Ping , Guo Shen‐rong , Song Cai‐sheng
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Aza‐Bicyclic Amino Acid Sulfonamides as α4β1/α4β7 Integrin Antagonists.
Authors: Dyatkin Alexey B. , et al. et al.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Application of Organolithium in Organic Synthesis: A Simple and Convenient Procedure for the Synthesis of More Complex 6‐Substituted 3H‐Quinazolin‐4‐ones.
Authors: El‐Hiti Gamal A.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Nevirapine‐Like Inhibitors with Improved Activity Against NNRTI‐Resistant HIV: 8 Heteroarylthiomethyldipyridodiazepinone Derivatives.
Authors: Yoakim C. , et al. et al.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Naturally Occurring Pyrazine and Imidazole Alkaloids from Botryllus Leachi.
Authors: Mahboobi Siavosh , Sellmer Andreas , Burgemeister Thomas , Lyssenko Alexei , Schollmeyer Dieter
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
The β‐Lactone Route to α,β‐Unsaturated δ‐Lactones. Total Syntheses of (.+‐.)‐Goniothalamin and (‐)‐Massoialactone.
Authors: Fournier Lycia , Kocienski Philip , Pons Jean‐Marc
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
EI‐2346, a Novel Interleukin‐1β Converting Enzyme Inhibitor Produced by Streptomyces sp. E‐2346. Part 1. Taxonomy of Producing Strain, Fermentation, Isolation, Physico‐chemical Properties, and Biological Properties.
Authors: Koizumi Fumito , Hasegawa Atsuhiro , Ochiai Keiko , Ando Katsuhiko , Kondo Hidemasa , Yoshida Mayumi , Matsuda Yuzuru , Nakanishi Satoshi
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Molecular Design of Heterogeneous Catalysts: The Case of Olefin Metathesis
Authors: Coperet Christophe
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Chiral Auxiliaries in Polymer‐Supported Organic Synthesis
Authors: Chung Cecilia Wan Ying , Toy Patrick H.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Ammonium, Oxonium and Sulfonium Ylides—Generation of Ammonium Ylides by Desilylation of α‐Silyl Ammonium Salts
Authors: Sato Yoshiro
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Enyne Metathesis (Enyne Bond Reorganization)
Authors: Diver Steven T. , Giessert Anthony J.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Novel Steroid Backbones via Photoinduced Electron Transfer Initiated Domino Cyclizations of Silyl Enol Ethers
Authors: Bunte Jens O. , Rinne Stefanie , Mattay Jochen
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Ultrafast Dynamics in Cluster Systems
Authors: Dermota T. E. , Zhong Q. , Castleman A. W. Jr.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Metabolic Aspects of Endotoxin as a Model of Septic Shock — Approach from Oxidative Stress
Authors: Sakaguchi Shuhei
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Ultrafast Guest Dynamics in Cyclodextrin Nanocavities
Authors: Douhal Abderrazzak
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Ultrafast Excited‐State Dynamics in Nucleic Acids
Authors: Crespo‐Hernandez Carlos E. , Cohen Boiko , Hare Patrick M. , Kohler Bern
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Many‐Body Approaches for Simulating Coherent Nonlinear Spectroscopies of Electronic and Vibrational Excitons
Authors: Mukamel Shaul , Abramavicius Darius
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Search of long biphase sequences for pulse compression using fractal dimension
Authors: Araki Kan , Miyoshi Akito
Published: May 2004

In this paper, we propose a search technique for low sidelobe, long biphase sequences that uses the fractal dimension and reduces the computational complexity. We selected the Legendre Sequence (LS) code having a compression ratio that can be relatively freely selected and can be easily implemented in hardware as the original code sequence, which becomes the starting point of the search. With the fractal dimension of a sign run of this sign sequence as the observed parameter of the decrease in the sidelobe in pulse compression, the first step is to invert each sign and search for an improvement in the sidelobe level. Furthermore, the sign inversion position is limited and the search computational complexity is drastically reduced by the sign decision of a change in the fractal dimension and the statistical distribution of the sign inversion position and the fractal dimension. By using this technique and selectively sorting the original LS code that is 1000 to 2500 signs long, an SLL improvement (maximum 1.3 dB) was seen for some codes, and the effect on existing LS codes was quantitatively verified. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 87–98, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10175
A study on high‐resolution target height estimation in multipath environment—subarray configuration
Authors: Inaba Takayuki , Araki Kiyomichi
Published: May 2004

It is well known that a large spike error and a bias error occur in the monopulse angle measurement process (of height estimation due to sea surface reflection or road surface reflection) when height estimation of a low‐altitude target is carried out with an air traffic control radar or a tracking radar with a monopulse antenna. In this paper, a target height estimation method is proposed that can seek the estimation object with only one parameter of the target height, even if fading prevention by frequency hopping and a subarray configuration of the array antenna based on the maximum likelihood estimation method is used. By means of computer simulation, the S/N dependence and equivalent earth radius error dependence of the target height estimation error are evaluated when the conventional ΣΔ monopulse method, the maximum likelihood estimation method without frequency hopping for four subarrays, and the proposed maximum likelihood estimation method with frequency hopping are used. Even though the evaluation is within the limited conditions, it is confirmed that the proposed method can estimate the target height while fading prevention is attempted in a multipath environment. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 39–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10208
Efficient Synthesis of Enantiomerically and Diastereomerically Pure [2.2]Paracyclophane‐Based N,O‐Ligands
Authors: Rozenberg Valeria I. , Danilova Tat’yana I. , Sergeeva Elena V. , Shouklov Ivan. A. , Starikova Zoya A. , Hopf Henning , Kühlein Klaus
Published: May 2004

Efficient syntheses of different enantiomerically and diastereomerically pure N,O‐ligands with alkylamino and phenol groups attached to the [2.2]paracyclophane framework are described. Several transformations of the ortho‐lithiated [2.2]paracyclophan‐4‐yl diethylcarbamate 7 and the reduction of the [2.2]paracyclophane imino derivatives 3, 4, 17, 18, and 21 allow the preparation of a wide range of compounds in which the chiral environment can be controlled by the planar chiral fragment and modified by the presence of one or two additional chiral centers in the alkylamino group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of a Shape‐Persistent Macrocycle with Intraannular Sulfonate Groups
Authors: Fischer Matthias , Höger Sigurd
Published: May 2004

The synthesis of a shape‐persistent macrocycle with two intraannular sulfonate groups is described. The cylization step is the oxidative acetylene coupling of large phenylethynyl oligomers which are covalently connected to a template. The synthesis of the templated acetylenes at the template as well as the cyclization step give high product yields showing that the template‐directed approach is superior to statistical oligocyclizations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Organometallic Control over the Regiospecificity of Functionalization Reactions: 1,2,3‐Trifluorobenzene and Bromo Derivatives thereof as Substrates
Authors: Heiss Christophe , Schlosser Manfred
Published: May 2004

In a case study, 1,2,3‐trifluorobenzene was functionalized at each of the two vacant positions (producing the benzoic acids 1 and 2) and, in addition, bromine was introduced into all available positions (producing the benzoic acids 3−5). The required regioflexibility was achieved by applying novel organometallic recipes such as deprotonation‐triggered halogen migrations and site‐discriminating competitive halogen−metal permutations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Homologous Series of O‐ and N‐Functionalized 2,2‐Difluoro1,3‐benzodioxoles: an Exercise in Organometallic Methodology
Authors: Schlosser Manfred , Gorecka Joanna , Castagnetti Eva
Published: May 2004

The conversion of 2,2‐difluoro‐1,3‐benzodioxole, an exceptionally acidic arene, via a 4‐lithiated intermediate into more than three dozen new derivatives was conceived as a case study. The lithiated species was trapped by C0‐electrophiles (4‐toluenesulfonyl azide, fluorodimethoxyborane, iodine), C1‐electrophiles (carbon dioxide, N,N‐dimethylformamide, formaldehyde, dimethyl sulfate), C2‐electrophiles (oxalic acid diesters, oxirane), C3‐electrophiles (oxetane), and higher alkyl iodides. The resulting carboxylic acid 1a may be treated with organolithium compounds to afford ketones (e.g. 10) and the aldehyde 9 can be condensed with nitromethane or acetic anhydride under basic conditions. If not oxidized with chromium trioxide to the corresponding carboxylic acids, the alcohols 2b, 2c, and 2d can be transformed into the corresponding bromides (12) or sulfonates (13). Their condensation with nitrogen‐containing C0‐nucleophiles (hydroxylamine, sodium azide, potassium phthalimide), C1‐nucleophiles (potassium cyanide), and C2‐nucleophiles (acetonitrile) opens a convenient access to the amines 3. Other reactions gave, despite a proven track record in other areas, only moderate yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactions of Silicon Atoms with Conjugated π‐Systems: A Matrix‐Spectroscopic Study
Authors: Maier Günther , Reisenauer Hans Peter
Published: May 2004

The reaction of silicon atoms with cyclopentadiene and butadiene in argon at 10 K has been studied. Addition to the conjugated π‐system of cyclopentadiene occurs in a [1,4]‐fashion. Upon irradiation the π‐adduct3rearranges to the formal insertion product2which has an unusual structure. Remarkably, a photoequilibrium between the twoexo,endoisomers2and4can be observed. In the case of butadiene the addition is less stereospecific. The planar [1,4]‐adduct11is formed together with the [1,2]‐adduct14. Surprisingly, besides11a second, nonplanar [1,4]‐adduct10can be detected. The isomers11and14are transformed into10upon irradiation. The final photoproduct is silole9. The structural elucidation of the new species is based on isotopic labelling and a comparison of the experimental observations with the results from density functional calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactions of Silicon Atoms with Benzene: A Matrix‐Spectroscopic Study
Authors: Maier Günther , Reisenauer Hans Peter
Published: May 2004

The reaction of silicon atoms with benzene in argon at 10 K has been studied. The addition to the aromatic π‐system of benzene occurs in a [1,4]‐fashion. Upon irradiation the π‐adduct 7‐silabicyclo[2.2.1]heptadien‐7‐ylidene (2) rearranges to the formal C−C insertion product 1‐silacycloheptatrienylidene (3). The structural elucidation of the new species is based on comparison of the experimental observations with density functional calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
On the Mechanism of the Oxygen Transfer to Sulfoxides by (Peroxo)[tris(hydroxyalkyl)amine]TiIV Complexes − Evidence for a Metal‐Template‐Assisted Process
Authors: Bonchio Marcella , Bortolini Olga , Licini Giulia , Moro Stefano , Nugent William A.
Published: May 2004

Oxidation of p‐XC6H4SOMe (X = NC, F3C) by (alkylperoxo){tris[(2R)‐2‐hydroxy‐2‐phenylethyl]amine}titanium (2b) has been shown to follow Michaelis−Menten kinetics demonstrating the occurrence of an intramolecular nucleophilic oxygen transfer to the TiIV‐coordinated sulfoxide. The reaction of the titanium(IV) precursors 1 with sulfoxides has been studied by ESI‐MS techniques together with ab initio calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Oxidation of Benzylic Alcohols and Ethers to Carbonyl Derivatives by Nitric Acid in Dichloromethane
Authors: Strazzolini Paolo , Runcio Antonio
Published: May 2004

Nitric acid in dichloromethane may be successfully employed for the oxidation of benzylic alcohols and ethers to the corresponding carbonyl compounds. The proposed method proved to be of general applicability, affording very good yields of aldehydes and ketones and showing interesting chemoselectivity in many instances, allowing competitive aromatic nitration to be avoided, as well as − in the case of aldehydes − any further oxidation to carboxylic acids. The reaction probably proceeds by a radical mechanism, the active species in the oxidation process being NO2. Competitive formation of nitro esters was observed in some cases, whereas poor results were obtained with allylic and non‐benzylic substrates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Concise and Efficient Synthesis of seco‐Duocarmycin SA
Authors: Tietze Lutz F. , Haunert Frank , Feuerstein Tim , Herzig Tobias
Published: May 2004

A short and efficient synthesis of seco‐duocarmycin SA (3), a highly potent cytostatic agent and direct precursor of the natural product duocarmycin SA (1), has been achieved. Starting from commercially available 2‐methoxy‐4‐nitroaniline (4) the synthetic protocol contains a Fischer indole synthesis to introduce the heterocyclic scaffold and a radical 5‐exo‐trig cyclization to furnish the (chloromethyl)indoline ring system as key reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Trend assessment in a long memory dependence model using the discrete wavelet transform
Authors: Craigmile Peter F. , Guttorp Peter , Percival Donald B.
Published: May 2004

In this article we consider trend to be smooth deterministic changes over long scales, and tackle the problem of trend estimation in the presence of long memory errors (slowly decaying autocorrelations). Using the fractionally differenced (FD) process as a motivating example of such a long memory process, we demonstrate how the discrete wavelet transform (DWT) is a natural choice at extracting a polynomial trend from such an error process. We investigate the statistical properties of the trend estimate obtained from the DWT, and provide pointwise and simultaneous confidence intervals for the estimate. Based on evaluating the power in the trend estimate relative to the estimated errors, we provide a test of nonzero trend. We finish by applying the methods to a climatological example. Copyright © 2004 John Wiley & Sons, Ltd.
PRDX4, a member of the peroxiredoxin family, is fused to AML1 (RUNX1) in an acute myeloid leukemia patient with a t(X;21)(p22;q22)
Authors: Zhang Yanming , Emmanuel Neelmini , Kamboj Ginny , Chen Jianjun , Shurafa Muhammad , Van Dyke Daniel L. , Wiktor Anne , Rowley Janet D.
Published: May 2004

The AML1 gene (also known as RUNX1) at 21q22 codes for core binding factor (CBF) α, which forms a heterodimer with CBF β that acts as a transcriptional activating factor. CBF is a critical regulator in the generation and differentiation of definitive hematopoietic stem cells and is frequently disrupted in leukemia through chromosome translocations. We cloned a novel AML1 partner gene, PRDX4, in an X;21 translocation in a 74‐year‐old male patient diagnosed with acute myeloid leukemia–M2. Chromosome analysis detected a t(X;21)(p22;q22) as the sole abnormality in bone marrow samples. The involvement of AML1 was confirmed by fluorescence in situ hybridization studies. Using 3′ RACE‐PCR, we cloned a fusion between exon 5 of AML1 and exon 2 of PRDX4. RT‐PCR confirmed the fusion and detected another fusion between exon 6 of AML1 and exon 2 of PRDX4, indicating alternative splicing of exon 6 of AML1 in the fusion transcripts. PRDX4 is one of six peroxiredoxin‐family genes that are highly conserved in eukaryotes and prokaryotes and are ubiquitously expressed. Peroxiredoxin genes exhibit thioredoxin‐dependent peroxidase activity and have been implicated in a number of other cellular functions such as cell proliferation and differentiation. PRDX4 plays a regulatory role in the activation of the transcription factor NF‐κB and is significantly down‐regulated in acute promyelocytic leukemia. This is the first example of antioxidant enzyme involvement in a chromosome translocation in leukemia. © 2004 Wiley‐Liss, Inc.
Microcell‐mediated chromosome transfer provides evidence that polysomy promotes structural instability in tumor cell chromosomes through asynchronous replication and breakage within late‐replicating regions
Authors: Kost‐Alimova Maria , Fedorova Ludmila , Yang Ying , Klein George , Imreh Stefan
Published: May 2004

It was reported earlier that normal chromosome 3 (chr3) transfer into tumor cells of different origin may suppress their ability to grow in SCID mice. Tumorigenicity may be restored by the loss of certain 3p regions. We transferred a normal cell‐derived chr3 into cells of a human renal cell carcinoma line and followed the chromosomal changes during in vivo and in vitro growth. In cells cultivated for 6 weeks or more and in the tumors grown in SCID mice, supernumerary chrs3 were always rearranged, accompanied by 3p losses. Unexpectedly, we found that the rearrangements affected not only the transferred exogenous chr3, but also the endogenous chrs3. Other chromosomes that were polysomic in the recipient cells were affected as well, suggesting that polysomy may be associated with structural chromosome instability. The dominant chromosomal aberrations were unbalanced translocations with preferentially pericentromeric breakpoints. The breakpoint distribution on chr3 preferentially affected the pericentromeric 3p11 (8 breaks) and 3p12–13 (5 breaks) regions. The regions 3p14 and 3q26–27 occasionally were involved as well (one break in each case). These four regions were the latest replicating, as shown by BrdU incorporation–based replication banding. Using fluorescence in situ hybridization–based replication timing, we detected asynchronous and incomplete centromere replication in cells with 3 or 4 copies of chr3, but not in cells with 2. We concluded that in tumor cells, asynchronous and incomplete replication of polysomic chromosomal parts is associated with aberrations that have breakpoints within the late‐replicating regions. This may explain the increased structural chromosome instability and preferential pericentromeric localization of breakpoints in hyperploid tumors. © 2004 Wiley‐Liss, Inc.
Nitrification by immobilized cells in a micro‐ecological life support system using packed‐bed bioreactors: an engineering study
Authors: Pérez J , Montesinos JL , Albiol J , Gòdia F
Published: May 2004

The nitrifying component of a micro‐ecological life support system alternative (MELISSA) based on microorganisms and higher plants was studied. The MELISSA system consists of an interconnected loop of bioreactors to allow the recycling of the organic wastes generated in a closed environment. Conversion of ammonia into nitrates in such a system was improved by selection of microorganisms, immobilization techniques, reactor type and operation conditions. An axenic mixed culture of Nitrosomonas europaea and Nitrobacter winogradskyi, immobilized by surface attachment on polystyrene beads, was used for nitrification in packed‐bed reactors at both bench and pilot scale. Hydrodynamics, mass transfer and nitrification capacity of the reactors were analysed. Mixing and mass transfer rate were enhanced by recirculation of the liquid phase and aeration flow‐rate, achieving a liquid flow distribution close to a well‐mixed tank and without oxygen limitation for standard operational conditions of the nitrifying unit. Ammonium conversion ranged from 95 to 100% when the oxygen concentration was maintained above 80% of saturation. The maximum surface removal rates were measured as 1.91 gN‐NH4+ m−2 day−1 at pilot scale and 1.77 gN‐NH4+ m−2 day−1 at bench scale. Successful scale‐up of a packed‐bed bioreactor has been carried out. Good stability and reproducibility were observed for more than 400 days. Copyright © 2004 Society of Chemical Industry
Anaerobic acidogenesis of dairy wastewater: the effects of variations in hydraulic retention time with no pH control
Authors: Demirel Burak , Yenigun Orhan
Published: May 2004

The performance of a laboratory‐scale mesophilic acidogenic reactor was evaluated in this study, in terms of volatile fatty acid production and distribution, with respect to variations in hydraulic retention time (HRT). The continuous flow‐completely mixed anaerobic reactor, coupled with a conventional gravity settling tank and a continuous recycling system, was operated in a hydraulic retention time ranging between 24 and 12 h, and up to an organic loading rate of about 9.3 kg COD m−3 d−1, without pH control. The acid production gradually increased proportionally to the organic loading rate, with decrease in hydraulic retention time. The highest degree of acidification and the rate of acid production were 56% and 3.1 g dm−3 d−1 at 12 h of HRT. Variations in hydraulic retention time affected volatile fatty acid production and distribution substantially, for the range investigated. Acetic, propionic, butyric and valeric acids were commonly produced during acidogenesis of dairy wastewater. Copyright © 2004 Society of Chemical Industry
Ultra‐fast essential oil characterization by capillary GC on a 50 μm ID column
Authors: Mondello Luigi , Shellie Robert , Casilli Alessandro , Quinto Tranchida Peter , Marriott Philip , Dugo Giovanni
Published: May 2004

A 5 m × 50 μm capillary column with 0.05 μm stationary phase film thickness, with a calculated efficiency of almost 20,000 plates per metre (under optimum conditions), was used for very fast high resolution GC analysis of lime essential oil. The total analysis time of this volatile essential oil was less than 90 s. Fast GC is shown to be appropriate for essential oil quality assurance analysis, and quantitative results of key components are comparable with those obtained by using conventional GC analysis. The fast GC analysis is approximately 33 times faster than the conventional GC method.
Analysis of sulfur‐containing compounds in crude oils by comprehensive two‐dimensional gas chromatography with sulfur chemiluminescence detection
Authors: Hua Ruixiang , Wang Jinghua , Kong Hongwei , Liu Jun , Lu Xin , Xu Guowang
Published: May 2004

This paper reports an analytical method for separating, identifying, and quantifying sulfur‐containing compounds in crude oil fraction (IBP‐360°C) samples based on comprehensive two‐dimensional gas chromatography coupled with a sulfur chemiluminescence detector. Various sulfur‐containing compounds and their groups were analyzed with one direct injection. 3620 peaks were detected including 1722 thiols/thioethers/disulfides/1‐ring thiophenes, 953 benzothiophenes, 704 dibenzothiophenes, and 241 benzonaphthothiophenes. The target sulfur compounds and their groups were identified based on the group separation feature and structured retention of comprehensive two‐dimensional gas chromatography as well as standard substances. The quantitative analysis of major sulfur‐containing compounds and total sulfur was based on the linear response of the sulfur chemiluminescence detector using the internal standard method. The sulfur contents of target sulfur compounds and their groups in 4 crude oil fractions were also determined. The recoveries for standard sulfur‐containing compounds were in the range of 90–102%. The quantitative result of total sulfur in the Oman crude oil fraction sample was compared with those from ASTM D 4294 standard method (total S by X‐ray fluorescence spectrometry), the relative deviation (RD%) was 4.2% and the precision of the method satisfactory.
Reduced‐bore monolithic silica column modified with C8‐TEOS for reversed‐phase electrochromatography
Authors: Qu Qishu , Qu Rongjun , Xu Qiang , Wang Yubao , Wang Xiaorong , He Youzhao
Published: May 2004

Monolithic silica columns of 2.7 mm ID were prepared and derivatized with C8‐TEOS and TEOS by on‐column sol‐gel reaction. These C8 large diameter monolithic silica columns gave 21 000 theoretical plates for aromatic hydrocarbons in 60% acetonitrile and 40% Tris‐HCl buffer. The surface areas as well as the separation reproducibility were improved on coating by the sol‐gel approach. Joule heating was greatly reduced by using monolithic columns to which fine quartz sand had been added during column preparation. Since this is a preliminary investigation on a monolithic column with such a large inner diameter, the separation efficiency was not so high as that presently achieved in normal capillary electrochromatography (CEC). However, use of the columns improved sample loadability and concentration detectability of electrochromatography, and semi‐preparative separations could be performed.
Interfacial phenomena in polymer films and generation of maxwell displacement current
Authors: Iwamoto Mitsumasa
Published: May 2004

Interfacial electrostatic phenomena in ultrathin polyimide films have been examined, and the space charge distribution and electronic density of states have been determined. The presence of excess negative charges at the film‐metal interface of nanometer thickness has been revealed and the alignment of the surface Fermi level of polymer films and Fermi level of metals have been elucidated. Taking into account the interfacial space charge, a step structure observed in the I‐V characteristic of metal‐polyimide‐rhodamine‐polyimide‐metal junction, very similar to Coulomb staircase, is well explained. Furthermore, the electrical breakdown mechanism of a nanometer‐thick polyimide film is found quite different from that of micrometer‐thick films, owing to the presence of this interfacial nanometric space charge. Finally, for a profound understanding of the behaviour of surface monolayer, the Maxwell displacement current measurement coupled with optical second harmonic generation measurement has been employed.
Traps for charge carriers in molecular materials formed by dipolar species: towards light‐driven molecular switch
Authors: Sworakowski Juliusz , Nešpůrek Stanislav
Published: May 2004

The influence of polar species on the transport and trapping of charge carriers is discussed. Calculations performed on a model molecular lattice demonstrate that polar dopants locally modify the polarization energy thus creating traps for charge carriers in the vicinity of the dipole. The presence of polar dopants in disordered solids gives rise to a broadening of the density‐of‐states function. A scheme of a molecular switch has been put forward, based on electrostatic interactions between photochromic moieties and charge carriers travelling on a molecular wire (conjugated polymer chain).
Correlation between large polarons in molecular chains
Authors: Brizhik Larissa , Eremko Alexander
Published: May 2004

We studied few extra electrons in a molecular chain with the account of electron‐phonon coupling in the adiabatic approximation. It is shown that the lowest state of two extra electrons in a chain corresponds to the singlet bisoliton state with one deformational potential well. Two electrons with parallel spins form a localised triplet state, which corresponds to the two‐hump charge distribution function. Three extra electrons form an almost independent nonlinear superposition of a soliton and bisoliton states. In the case of four electrons, the two almost independent bisolitons are formed. These two states tend to separate in the chain at the maximal distance due to the Fermi repulsion, accounted for in the zero‐order adiabatic approximation. This repulsion is partly compensated by the attraction between the solitons due to their exchange with virtual phonons, described by the non‐adiabatic part of the Hamiltonian. The formation of solitons is characterised by the appearance of the bound soliton and bisoliton levels in the forbidden energy band. This constitutes the qualitative difference of the large polaron (soliton) states from the almost free electron states and small polaron states.
Design of molecular magnets
Authors: Yakhmi J.V.
Published: May 2004

The conventional magnetic materials used in present‐day technology, such as Fe, Fe2O3, Cr2O3, SmCo5, Nd2Fe14B, etc. are all atom‐based, whose synthesis requires high‐temperature routes. Employing ambient‐temperature synthetic organic chemistry, it has become possible to engineer a bulk molecular material with long‐range magnetic order, primarily due to the weak nature of intermolecular interactions in it. Typical synthetic approach to design molecule‐based magnets consists of choosing molecular precursors, each bearing an unpaired spin, and assembling them in such a way that there is no compensation of spins at the scale of the crystal lattice. Magnetism being a co‐operative effect, the spin‐spin interaction must extend to all the three dimensions, either through space or through bonds. Specific occurrence of ‘spin delocalisation’ and ‘spin polarisation’ in molecular lattices is helpful in bringing about ferromagnetic interaction by facilitating necessary intermolecular exchange interactions. Since the first successful synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be classified on the basis of the chemical nature of the magnetic units involved: organic systems, metal‐based systems, hetero‐bimetallic assemblies, or mixed organic‐inorganic systems. The design of molecular magnets has also opened the doors for the unique possibility of designing polyfunctional molecular materials, such as magnets exhibiting second‐order optical nonlinearity, liquid crystalline magnets, or chiral magnets. Solubility of molecular magnets, their low density and biocompatibility are attractive features. Being weakly colored, unlike the opaque classic magnets, possibilities of photomagnetic switching can be envisaged. Persistent efforts continue to design the ever‐elusive polymer magnets for applications in industry. While providing a brief overview of the field of molecular magnetism, we highlight some recent developments, with emphasis on a few studies from the author's own lab.
Optical rotatory power of biodegradable polylactic acid films
Authors: Tajitsu Yoshiro
Published: May 2004

Polylactic acid (PLA) is a polymer material on which biodegradability research has been the most advanced. PLA is a chiral polymer in which molecules containing asymmetric carbon atoms have a helical structure. Two optical isomers of PLA exist, PLLA (poly(L‐lactic acid)) and PDLA (poly(D‐lactic acid)). In this study, using various physical processes, we fabricated various samples such as oriented PLLA film, PLLA fiber, rolled PLLA film and forged PLLA plate. We observed a large optical rotatory power ρ in the cylindrical plate fabricated using a forging process. ρ of forged PLLA plates is 7200°/mm which is approximately 300 times larger than that of α‐quartz.
Features of charge carrier concentration and mobility in π‐conjugated polymers
Authors: Juška Gytis , Genevičius Kristijonas , Arlauskas Kęstutis , Österbacka Ronald , Stubb Henrik
Published: May 2004

We show the possibilities of experimental investigation of charge carrier mobility and concentration features by extraction methods of equilibrium, photoexcited and injected charge carriers in π‐conjugated polymers, where, due to relatively high conductivity, the classic time‐of‐flight method is inappropriate.
Infrared and Raman studies of the charge ordering in the organic semiconductor κ‐[Et4N][Co(CN)6(ET)4]·3H2O
Authors: Świetlik Roman , Ouahab Lahcène , Guillevic Joseph , Yakushi Kyuya
Published: May 2004

Polarised infrared reflectance and Raman spectra of the charge transfer salt κ‐[Et4N][Co(CN)6(ET)4]·3H2O were measured as a function of temperature. The salt undergoes a phase transition at 150 K, which is related to a charge ordering inside conducting ET layers. The charge ordering has a considerable influence on vibrational as well as electronic spectra. New vibrational bands related to ET+ cations are seen below 150 K. Moreover, formation of a new energy gap (charge gap) in electronic excitation spectrum is observed.
Ultraweak spectrally resolved thermoluminescence in polymers
Authors: Mandowska Ewa , Mandowski Arkadiusz , Świątek Józef
Published: May 2004

Spectrally resolved thermoluminescence (TL) measurements provide a lot of information concerning trapping and recombination states in various dielectric materials. As long‐lived luminescence is typically weak, this technique requires a very sensitive apparatus. This paper describes the measurement system that is used for studying spectrally resolved TL and phosphorescence decay in polymers. Exemplary investigations are presented for poly(N‐vinylcarbazole) (PVK) thin films. The obtained spectra clearly indicate the influence of solvents (dioxane, chlorobenzene) and excitation wavelengths on TL in PVK samples.
Recombination in complex systems – an analytical approach
Authors: Mandowski Arkadiusz
Published: May 2004

A new analytical model is proposed to describe the kinetics of trapping and recombination of charge carriers in complex systems with an arbitrary spatial distribution of traps and recombination centres. The structural properties of a material are described by two functions Γm and Γn irrespective of the thermal history of the sample. A simple method is proposed to determine the function Γm from simultaneous thermoluminescence (TL) and thermally stimulated conductivity (TSC) measurements.
Effect of spatial irregularities on the temperature and field dependence of the mobility in liquid‐crystalline conjugated polymer films
Authors: Martin Simon J. , Kambili Agapi , Walker Alison B.
Published: May 2004

We have performed simulations of time‐of‐flight measurements via the Monte Carlo approach for films made of conjugated polymers in the liquid‐crystalline phase. In spatially regular films with a distribution of on‐site energies the mobility is affected by the interplay between electrostatic and thermal energy. When the width of the on‐site energy distribution is comparable to the thermal energy, the mobility increases with temperature at low fields, but shows the opposite behaviour at larger fields. However, when spatial irregularities in the arrangement of the film are introduced, the mobility is enhanced at all temperatures, as the electrostatic energy plays less of a role in charge transport than thermal activation over energy barriers.
Kinetics of refractive index changes in polymeric photochromic films
Authors: Ortyl Ewelina , Kucharski Stanisław
Published: May 2004

Methacrylate copolymers containing, in side chain azobenzene groupings with heterocyclic sulfonamide substituents: N‐(2,6‐dimethylpyrimidin‐4‐yl)sulfamoyl (sulfisomidine) and N‐(5‐methylisoxazol‐3‐yl) sulfamoyl (sulfamethoxazole) were investigated. The materials undergo reversible trans‐cis isomerisation during illumination with light. This results in changes of dipole moment, polarizability and refractive index. Ellipsometric measurements showed a distinct decreasing refractive index during illumination with light corresponding to absorption band (ca. 450 nm). Depending on the polymer, the change of real part of refractive index in spin‐coated films was between 0.016 and 0.031. The dynamics of growth and decay of refractive index changes, was described by biexponential function approach.
Electrical conductivity of polycrystalline films of p‐sexiphenyl
Authors: Tkaczyk Stanislaw , Świątek Jozef
Published: May 2004

In this work the results of DC conductivity measurements of polycrystalline p‐sexiphenyl thin films are presented. The investigations concerned the effect of temperature, film thickness and electric field on the DC conductivity mechanism. The thickness of the investigated material varied from 0.2 to 2.5 μm. The measurements were carried out for different electrode polarities of the 0 ‐100 V voltage and at temperatures ranging from 15 to 325 K. Thin films of p‐sexiphenyl were obtained by controlled vacuum sublimation on BK‐7 glass substrate with gold and aluminium electrodes. Analyzing the obtained results we conclude that injection of the charge carrier from electrodes into the investigated material proceeds by thermionic emission and field emission and it is dependent on temperature and external electric field. The charge carrier transport is controlled by localized states (traps) in the forbidden energy gap. The activation energy calculated from formula ln I = f(1/kT) varied from kT for low temperature up to 1.0 eV.
Photovoltaic properties of tetracene and pentacene layers
Authors: Signerski Ryszard , Jarosz Grażyna , Godlewski Jan
Published: May 2004

Photovoltaic phenomenon in tetracene and pentacene layers evaporated under the same conditions onto a glass substrate and provided with the same couple of electrodes is investigated. Comparison of the results obtained for both organic materials makes it possible to conclude that in spite of differences in mechanisms of charge carrier generation, the values of photovoltaic parameters are very similar.
Lattice dynamics and electron‐phonon coupling in pentacene crystal structures
Authors: Masino Matteo , Girlando Alberto , Brillante Aldo , Farina Luca , Della Valle Raffaele Guido , Venuti Elisabetta
Published: May 2004

The crystal structures and lattice phonons of pentacene are computed by the quasi harmonic lattice dynamics (QHLD) method. From the eigenvectors of the low frequency phonons we calculate the e‐ph coupling constants due to the modulation of the transfer integrals. The transfer integrals are computed by the Hückel method and by the INDO/S Hamiltonian for all the nearest neighbor pentacene pairs in the ab crystal plane.
Dispersive and non‐dispersive hole transport in fluorene‐arylamine copolymers
Authors: Poplavskyy Dmitry , Nelson Jenny , Bradley Donal D.C.
Published: May 2004

Hole transport in two fluorene‐arylenediamine copolymers is studied by means of time‐of‐flight (ToF) and space‐charge‐limited dark‐injection (SCL DI) transient current methods. Non‐dispersive and dispersive hole transport is observed for a range of sample thicknesses, applied electric fields and temperatures.
Influence of morphological and conformational changes on the molecular mobility in poly(ethylene naphthalene‐2,6‐dicarboxylate)
Authors: Colombini Didier , Zouzou Noureddine , Martinez‐Vega Juan Jorge
Published: May 2004

Dynamic electric (DEA) and mechanical (DMA) analyses were combined to explore the relaxational processes in amorphous and semicrystalline poly(ethylene naphthalene‐2,6‐dicarboxylate) (PEN) samples. Differential scanning calorimetry measurements were carried out to investigate the crystallinity of the samples following isothermal annealing treatment at 443 K. The two secondary relaxations β and β*, the main α relaxation, as well as the ρ‐relaxational process, were revealed by both electric and mechanical viscoelastic responses of the PEN samples. DMA results clearly identified the above Tα loss factor peak, ρ, as a probe of the cold crystallization. However, the association of both DMA and DEA investigations pointed out that electric and non‐electric aspects might govern the ρ‐process.
Influence of carbazol‐9‐yl substitution in polysilanes on charge carrier trapping and recombination
Authors: Glowacki Ireneusz , Dobruchowska Ewa , Luszczynska Beata , Ulanski Jacek
Published: May 2004

A series of poly{[3‐(carbazol‐9‐yl)propyl]silane‐co‐methylphenylsilane}s were investigated by optical absorption, photoluminescence and thermoluminescence measurements. It was found that the optical absorption bands of the carbazolyl side groups superimpose on those of the Si backbones in the ultraviolet range. This feature reduces photodegradability of Si‐Si bonds during UV irradiation. The TL spectra recorded in the 15 ‐ 325 K temperature range after photoexcitation at 15 K show that the carbazolyl side groups act as trapping sites in polysilanes. Increasing density of carbazolyl groups results in increasing population of deeper (ca. 150 meV) traps. Spectral analyses of the thermoluminescence at different temperatures are discussed and compared with analogous results for poly(9‐vinylcarbazole) (PVK). It is concluded that the monomeric mechanism of luminescence dominates at low temperatures while the excimeric mechanism prevails at higher temperatures, similarly to PVK.