bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal expansion, pyroelectricity and linear optical properties of Li2SeO4·H2O and Li2SO4·H2O
Authors: Becker P. , Ahrweiler S. , Held P. , Schneeberger H. , Bohatý L. 
Published: September 2003

AbstractLarge single crystals of polar Li2SeO4·H2O were grown at 343 K from aqueous solution. Temperature dependent thermal expansion coefficients of Li2SeO4·H2O and Li2SO4·H2O were determined within the temperature range 133 K–313 K and coefficients of the pyroelectric effect within the temperature range 183–343 K. Refractive indices between 365 nm and 1530 nm as well as unpolarized absorption spectra of Li2SeO4·H2O and Li2SO4·H2O were measured and phase‐matching curves for second harmonic generation were calculated. Both compounds allow type I and type II phase‐matching at wavelengths from about 650 nm to the near infrared region. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Organomagnesium Phosphanide “Grignard” Analogues − Synthesis, Structural Characterisation and Solution Behaviour of [BuMg{P(CH[SiMe3]2)(C6H3‐2‐OMe‐3R)}]2 [R = H, Me]
Authors: Blair Stuart , Izod Keith , Clegg William , Harrington Ross W. 
Published: September 2003

AbstractThe reaction between either one or two equivalents of the secondary phosphane {(Me3Si)2CH}PH(C6H3‐2‐OMe‐3‐R′) [R′ = H (1a), Me (1b)] and Bu2Mg yields the heteroleptic complexes [BuMg{P[CH(SiMe3)2](C6H3‐2‐OMe‐3‐R′)}]2 [R′ = H (2a), Me (2b)], irrespective of the ratio of 1 to Bu2Mg. X‐ray crystallography shows that 2a and 2b crystallise as dimers containing a central Mg2P2 core. Dissolution of either 2a or 2b in THF results in complex degradation and formation of the tertiary phosphanes {(Me3Si)2CH}P(Me)(C6H3‐2‐OMe‐3‐R′) and unidentified magnesium‐containing products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds
Authors: Davies Robert P. , Martinelli M. Giovanna , Wheatley Andrew E. H. , White Andrew J. P. , Williams David J. 
Published: September 2003

AbstractLithium tellurophosphinite [Ph2PTe][Li(TMEDA)1.33(THF)1.33] (4), ditellurophosphinate, [Ph2PTe2][Li(THF)3.5(TMEDA)0.25] (5), and selenotellurophosphinate [Ph2P(Se)Te][Li(THF)2(TMEDA)] (6) complexes have been prepared from the insertion/oxidation reactions of lithiated secondary phosphanes with elemental chalcogens and characterised by X‐ray crystallography. Compounds 4−6 contain no tellurium−lithium bonding interactions in the solid state, instead existing as ion‐separated species with THF/TMEDA‐solvated lithium cations. Reaction of dilithiated primary phosphanes with more than three equivalents of elemental selenium gives [{(c‐C6H11)P(Se)(SeLi)}2·2TMEDA] (7) via a phosphorus‐phosphorus coupling reaction. Solid state characterisation of 7 reveals the organo groups in the tetradentate tetraselenohypodisphosphinate ligand to be in an anti conformation to one another and each lithium atom to be coordinated by two selenium atoms, one from each of the diselenophosphinate groups. Multinuclear NMR spectroscopic data are consistent with retention of the solid‐state structures of 4−7 in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structural Diversity in Lewis‐Base Complexes of Lithium Triflamide
Authors: Davidson Matthew G. , Raithby Paul R. , Johnson Andrew L. , Bolton Philip D. 
Published: September 2003

AbstractComplexation of the salt lithium triflamide [LiNTf2; NTf2 = N(SO2CF3)2], with a range of nitrogen donor ligands results in the formation of a series of coordination complexes [(Tf2N)Li·N(H)PPh2Me] (1), [(Tf2N)Li·N(H)PPh3] (2), [(Tf2N)Li·TMEDA] (3), [(Tf2N)Li·PMDTEA] (4) and [(Bz‐TAC)2Li][NTf2] (5). The molecular structures of 1, 3, 4 and 5 have been determined by single‐crystal X‐ray diffraction. The resulting solvated structures are discussed in terms of solvent‐separated ion pairs, contact ion pairs and higher aggregates, with the degree of aggregation and ion contact being dependent on the relative coordinating abilities and steric demands of the donor ligand and the anion, and provide an insight into the possible structures of lithium aggregates present in complex systems such as polymer electrolytes and synthetic reaction media. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Heteroaromatic Oligoamides with dDNA Affinity
Authors: Gallmeier Hans‐Christoph , König Burkhard 
Published: September 2003

AbstractHeteroaromatic oligoamides are selective ligands for sequence‐specific dDNA binding, many artificial oligoamides modeled on naturally occurring compounds and their dDNA binding motifs having been prepared over the last ten years. The large number of reported individual compounds does not allow each structure to be covered within the scope of this review, so we concentrate on examples of the most successful linear and tethered oligoamide structures, such as hairpin, H‐pin, or cyclic structures, and the ensemble of heteroaromatic amino acids used as their building blocks. This provides an overview of which chemical structures are currently in use for sequence‐specific dDNA recognition by artificial ligands and what they can achieve. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Enantioselective Synthesis of the Pyrrolidine Core of Endothelin Antagonist ABT‐627 (Atrasentan) via 1,2‐Oxazines
Authors: Buchholz Monika , Reißig Hans‐Ulrich 
Published: September 2003

AbstractDiastereoselective syntheses of the pyrrolidine core 6a of the endothelin antagonist ABT‐627 (Atrasentan) either as a racemic mixture or as an enantiopure compound are presented. The crucial steps of these syntheses utilized the highly diastereoselective conjugate addition of 1,3‐benzodioxol‐5‐yllithium to racemic 6H‐1,2‐oxazine 3 or enantiopure 6H‐1,2‐oxazines 7 or 8, followed by trapping with ethyl cyanoformate (Mander′s reagent). The resulting 5,6‐dihydro‐4H‐1,2‐oxazines were transformed into the 2,3,4‐trisubstituted pyrrolidine 6a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Acid‐Catalyzed Conversion of 7‐Ethynyl‐ and 7‐Vinylcyclohepta‐1,3,5‐trienes to Substituted Benzene Derivatives
Authors: Minegishi Shinya , Kamada Jun , Takeuchi Ken’ichi , Komatsu Koichi , Kitagawa Toshikazu 
Published: September 2003

AbstractThe acid‐catalyzed rearrangement in THF/TFA (5:1, v/v) of cyclohepta‐1,3,5‐trienes containing an α,β‐unsaturated substituent at C‐7 was investigated. 7‐Ethynylcyclohepta‐1,3,5‐triene (1a) and its 1,4‐di‐tert‐butyl (1b), 1,5‐di‐tert‐butyl (1c), and 2,5‐di‐tert‐butyl (1d) derivatives underwent isomerization to phenylallenes 2, 3, 7, and 3, respectively. 2,5‐Di‐tert‐butyl‐7‐vinylcyclohepta‐1,3,5‐triene (17) gave a mixture (66:34) of (E)‐ and (Z)‐1,4‐di‐tert‐butyl‐2‐(1‐propenyl)benzene (20). A mechanism involving the protonation of the norcaradiene tautomer (NCD), which is in equilibrium with cycloheptatriene (CHT) 1 or 17, followed by the cleavage of a three‐membered ring to give an arenium ion, is proposed. In contrast, 2,5‐di‐tert‐butyl‐7‐cyanocyclohepta‐1,3,5‐triene (12) and bis(cyclohepta‐2,4,6‐trien‐1‐yl)ethyne (21) did not give the expected products, probably due to the unfavorable energetics of the ring‐opening step. A thermal 1,5‐hydrogen shift predominates in these cases. Kinetic studies indicated that the rearrangement of 1a is significantly accelerated by the presence of tert‐butyl groups on the seven‐membered ring. The order of reactivity, 1a < 1b < 1c < 1d, is in agreement with the population of NCD forms at equilibrium, as estimated by the calculated CHT−NCD energy‐difference and the 13C NMR chemical shifts of 1a−d, indicating the importance of the equilibrium concentration of the norcaradiene form as a rate‐controlling factor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Electronic Properties of Alkynylated Phenothiazines
Authors: Krämer Christa S. , Müller Thomas J. J. 
Published: September 2003

AbstractAlkynylated phenothiazines 1, 2, 5, 7, and 12−15 can be synthesized in moderate to excellent yields by sequences of aldehyde−alkyne transformations and/or Sonogashira cross‐coupling reactions from suitable phenothiazine aldehydes or bromides. The electronic properties of (hetero)aryl ethynyl‐substituted N‐methyl‐phenothiazines (UV/Vis absorption, fluorescence, redox potentials) strongly correlate with Hammett σP parameters and indicate that remote substituents transmit their electronic information through π‐electron delocalization and the σ‐framework. Phenothiazinyl dyads (7g, 12, 13) and triads (14) reveal different degrees of intramolecular electronic coupling as demonstrated by cyclic voltammetry, qualifying them as good model candidates for redox‐active molecular wires. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Gold‐Catalyzed Hydroarylation of Alkynes
Authors: Reetz Manfred T. , Sommer Knut 
Published: September 2003

AbstractThe hydroarylation of aryl‐substituted alkynes by substituted electron‐rich arenes is catalyzed by AuCl3 activated by such silver salts as AgSbF6. In the case of terminal alkynes, complete regioselectivity in favor of the 1,1‐disubstituted olefin is observed. In the case of electron‐poor alkynes such as acetylenecarboxylic acid ester, gold(I) complexes such as [Ph3PAuCl] activated by Ag salts or BF3·OEt2 are the best catalysts, resulting in opposite regioselectivity and high degrees of (Z)‐selectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
3‐Functionalized Tetronic Acids From Domino Rearrangement/Cyclization/Ring‐Opening Reactions of Allyl Tetronates
Authors: Schobert Rainer , Gordon Gary J. , Bieser Arno , Milius Wolfgang 
Published: September 2003

AbstractAllyl tetronates 1 thermally rearrange to stable 3‐(spirocyclopropyl)dihydrofuran‐2,4‐diones 2 (R3 = H, Aryl), which can be ring‐opened with O‐, N‐, S‐ and C‐nucleophiles to give 3‐substituted tetronic acids 3−7. Compounds 2 with R3 = Alkyl are not isolable, but are interceptable intermediates in formal [2,3]‐sigmatropic rearrangements of allyl tetronates. The vinylogous hexadienyl tetronate 17 undergoes a different domino [3,5]‐rearrangement/cyclization reaction to give the 2H,5H‐furano[4,3‐b]oxepin‐6‐one 19. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Oligoarabinofuranosides from the Mycobacterial Cell Wall
Authors: Marotte Karine , Sanchez Sylvie , Bamhaoud Toufiq , Prandi Jacques 
Published: September 2003

AbstractOligoarabinofuranosides 1−4, fragments of the arabinan components found in the mycobacterial cell wall have been synthesized. 1 and 2 are representative of the structural features of the internal core of arabinogalactan, arabinomannan and lipoarabinomannans. 3 is the capping motif of the lipoarabinomannan of Mycobacterium tuberculosis and M. bovis BCG while 4 is the hexasaccharide found at the non‐reducing end of arabinogalactan. Complete stereocontrol was achieved for the elaboration of glycosidic linkages between arabinofuranoside units: α‐glycosides were obtained by participation of an ester or carbonate group on the 2‐position, while β‐arabinofuranosides were secured by an internal aglycon delivery approach. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The feasibility of intraoperative diagnosis of sentinel lymph node metastases in breast cancer
Authors: Leidenius Marjut Hannele Kristiina , Krogerus Leena Anneli , Toivonen Terttu Sinikka , von Smitten Karl Johan Albert 
Published: September 2003

AbstractBackground and ObjectivesThe aim of the study was to analyse in detail the feasibility of intraoperative assessment of sentinel lymph nodes in breast cancer.MethodsAltogether 139 consecutive breast cancer patients with metastases in axillary sentinel nodes were included in a prospective study. A combination of imprint cytology and frozen section was used as the method of intraoperative diagnosis of sentinel node metastases. The definite postoperative evaluation of the sentinel nodes was taken as the gold standard.ResultsThe overall sensitivity of intraoperative diagnosis was 83%, reaching 81% if the intraoperative assessment had been limited to the two first retrieved sentinel nodes. False negative (FN) findings were more common in connection with invasive lobular carcinoma (28%) than with invasive ductal carcinoma (8%) (P < 0.01) as well as in connection with micro‐metastases, in 38% of the cases, compared to the larger metastases, 6% (P < 0.00005).ConclusionsIntraoperative examination of sentinel lymph nodes enables breast surgery, axillary staging, and treatment in the same operation in a substantial proportion of breast cancer patients. Hospital costs as well as workload in the pathology laboratory may be reduced, limiting the intraoperative assessment to the two first retrieved nodes. J. Surg. Oncol. 2003;84:68–73. © 2003 Wiley‐Liss, Inc.
On summability of bilinear operators
Authors: Carando Daniel , Dimant Verónica 
Published: September 2003

AbstractWe study some properties of strongly and absolutely p‐summing bilinear operators. We show that Hilbert‐Schmidt bilinear mappings are both strongly and absolutely p‐summing, for every p ≥ 1. Giving an example of a strongly 1‐summing bilinear mapping which fails to be weakly compact, we answer a question posed in [6]. We prove that, as in the linear case, every bilinear operator from ℒ︁∞‐spaces to an ℒ︁2‐space is absolutely 2‐summing. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inhibition of cutaneous ultraviolet light B–mediated inflammation and tumor formation with topical celecoxib treatment
Authors: Wilgus Traci A. , Koki Alane T. , Zweifel Ben S. , Kusewitt Donna F. , Rubal Patricia A. , Oberyszyn Tatiana M. 
Published: September 2003

AbstractInflammation, which includes the release of growth factors, proinflammatory cytokines and prostaglandins, the infiltration and activation of inflammatory cells, and the induction of oxidative DNA damage, is known to play a role in cancer development. The combination of damage to the skin resulting from chronic ultraviolet light B (UVB) exposure itself and the inflammatory response it induces is a major source of skin cancer development. Cyclooxygenase‐2 (COX‐2), an inflammatory enzyme responsible for the production of prostaglandins, is now implicated in the development of epithelial cancers, including squamous cell carcinoma in the skin. Previous work conducted in our laboratory has shown that topical treatment with celecoxib following UVB irradiation inhibits several parameters of acute inflammation, including vascular permeability, the infiltration and activation of neutrophils, and the production of prostaglandin E2 (PGE2). The present studies expanded these observations, demonstrating the ability of topical celecoxib to inhibit acute oxidative damage. In addition, long‐term studies illustrate the effectiveness of topical treatment with this drug in reducing chronic inflammation and UVB‐induced papilloma/carcinoma formation. This data provides compelling evidence to explore the clinical efficacy of topically applied COX‐2 inhibitors for the prevention of human skin cancers. © 2003 Wiley‐Liss, Inc.
Travelling for radiation cancer treatment: Patient perspectives
Authors: Fitch Margaret I. , Gray Ross E. , McGowan Tom , Brunskill Ian , Steggles Shawn , Sellick Scott , Bezjak Andrea , McLeese Donna 
Published: September 2003

AbstractRadiation treatment for cancer requires patients to receive frequent administrations and attend the treatment facility on a daily basis for several weeks. Travelling for radiation treatment has the potential to add to the distress an individual may be feeling. This study utilized in‐depth interviews to capture 118 patients' perspectives about travelling for cancer treatment. Four themes emerged during the analysis of the data: (1) waiting was the most difficult part of the experience; (2) the idea of travelling for treatment was distressing; (3) travelling for treatment was tiring and posed difficulties for patients; and (4) being away from home had both benefits and drawbacks. Given the inevitability of travelling for radiation treatment, and the issues that arises for patients, supportive strategies need to be designed and implemented. Copyright © 2003 John Wiley & Sons, Ltd.
Quality of life of breast cancer patients in Taiwan: Validation of the Taiwan Chinese version of the EORTC QLQ‐C30 and EORTC QLQ‐BR23
Authors: Chie Wei‐Chu , Chang King‐Jen , Huang Chiun‐Sheng , Kuo Wen‐Hong 
Published: September 2003

AbstractThe objective of this study was to test the reliability and validity of the Taiwan Chinese version of the EORTC QLQ‐C30 (version 3) and EORTC QLQ‐BR23. The authors followed the guidelines of translation and pilot testing of the questionnaires. The questionnaires were given to 35 breast cancer patients under active treatment and 54 under follow‐up at the National Taiwan University Hospital from November 2000 to October 2001. A retest was conducted one to two weeks after the first interview/form completion for the follow‐up group. The intraclass correlation coefficients of the two questionnaires were moderate to high in the follow‐up group. The Cronbach's α coefficients of most scales of the two questionnaires were ≥ 0.70 except that of physical functioning (0.68), cognitive functioning (0.53), and arm symptoms (0.59). Correlations of scales measuring similar dimensions of the EORTC QLQ‐C30 and the SF‐36 were moderate. Patients in the active treatment group had more serious QOL problems due to disease and treatment. Results of this study showed that the Taiwan Chinese version of the two questionnaires had good test/retest reliability, high internal consistency in most scales, and could show the expected differences between patients in active chemotherapy and follow‐up group. Copyright © 2003 John Wiley & Sons, Ltd.
Quantization of the optical phase space in terms of the group
Authors: Kastrup H.A. 
Published: September 2003

AbstractThe problem of quantizing properly the canonical pair “angle and action variables”, φ and I, is almost as old as quantum mechanics itself and since decades an intensively debated but still unresolved issue in quantum optics. The present paper proposes a new approach to the problem, namely quantization in terms of the group SO(1,2): The crucial point is that the phase space has the global structure (a simple cone) and cannot be quantized in the conventional manner. As the group SO(1,2) acts transitively, effectively and Hamilton‐like on that space its irreducible unitary representations of the positive discrete series provide the appropriate quantum theoretical framework. The phase space has the conic structure of an orbifold . That structure is closely related to a Z2 gauge symmetry which corresponds to the center of a 2‐fold covering of SO(1,2), the symplectic group . The basic variables on the phase space are the functions h0 = I, h1 = I cos φ and h2 = ‐I sin φ the Poisson brackets of which obey the Lie algebra . In the quantum theory they are represented by the self‐adjoint Lie algebra generators K0, K1, and K2 of a unitary representation, where K0 has the spectrum {k + n, n = 0, 1, …; k > 0}. A crucial prediction is that the classical Pythagorean relation h12 + h22 = h02 can be violated in the quantum theory. For each representation one can define three different types of coherent states the complex phases of which may be “measured” by means of the operators K1 and K2 alone without introducing any new phase operators! The SO(1,2) structure of optical squeezing and interference properties as well as that of the harmonic oscillator are analyzed in detail. The additional coherent states can be used for the introduction of (Husimi type) “Q” distributions and (Sudarshan‐Glauber type) “P” representations of the density operator. The three operators K0, K1, and K2 are fundamental in the sense that one can construct composite position and momentum operators out of them! The new framework poses quite a number of fascinating experimental and theoretical challenges.
Total chemical synthesis of enzymes
Authors: Kent Stephen 
Published: September 2003

AbstractThe total synthesis, at will, of a wide variety of protein and enzyme molecules is made feasible by modern chemical ligation methods. As Emil Fischer intuitively understood, synthetic access to the enzyme molecule enables the power of chemical science to be applied to elucidating the molecular basis of catalytic function in unprecedented detail. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Synthetic glycopeptides for the development of tumour‐selective vaccines
Authors: Kunz Horst 
Published: September 2003

AbstractBased on structural information reported for the tumour‐associated epithelial mucin MUC1, glycopeptides have been synthesized which contain tumour‐associated saccharide antigens, such as the Thomsen‐Friedenreich (T), TN or sialyl TN antigen, in combination with peptide sequences of the tandem repeat region of MUC1. Solid‐phase syntheses have been carried out using N‐Fmoc protected O‐glycosyl serine and threonine building blocks and an allylic anchor which is stable to basic and acidic conditions, but can be cleaved under neutral conditions in a palladium(0)‐catalysed allyl transfer reaction. In addition, a (2–3)sialyl T antigen threonine building block was prepared by a chemoenzymatic strategy and used in the synthesis of an N‐terminal glycopeptide antigen of leukosialin (CD43). The proliferation of cytotoxic T cells could be induced using a construct consisting of a MUC1‐glycopeptide antigen and a T cell epitope Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
New aspects of galectin functionality in nuclei of cultured bone marrow stromal and epidermal cells: biotinylated galectins as tool to detect specific binding sites
Authors: Purkrábková Tereza , Smetana Karel , Dvořánková Barbora , Holíková Zuzana , Böck Corina , Lensch Martin , André Sabine , Pytlík Robert , Liu Fu‐Tong , Klíma Jiří , Smetana Karel , Motlík Jan , Gabius Hans‐Joachim 
Published: October 2003

AbstractNuclear presence of galectins suggests a role of these endogenous lectins in the regulation of transcription, pre‐mRNA splicing and transport processes. Therefore, detection and localization of nuclear binding sites for galectins by a new methodological step, has potential to further functional analysis. In the first step of our model study we monitored the nuclear expression of galectins‐1 and −3 in cultured stromal cells of human bone marrow and human/porcine keratinocytes. To enable detection and localization of galectin‐specific binding sites, we used purified galectins biotinylated without loss of activity as cytochemical tool. The degree of labeling of the probes was determined by adapting two‐dimensional gel electrophoresis and calculating pI changes in response to stepwise chemical modification of basic and acidic side chains by the biotinylation reagents. Binding studies revealed positivity for galectin‐1, whereas galectins‐3, −5, and −7 were not reactive with nuclear sites under identical conditions in bone marrow stromal cells and keratinocytes prepared from hair follicle enriched for stem cells. Inhibition by lactose indicated an involvement of the carbohydrate recognition domain in nuclear binding of galectin‐1. Colocalization of the galectin‐1‐dependent signal with the SC35 splicing factor and sensitivity toward RNase treatment argued in favor of galectin binding in nuclear speckles, albeit only for a small fraction of the cells. Epidermal cells positive for galectin‐1‐binding sites expressed ΔNp63 known as a potential marker of stem cells. Based on cytokeratin expression cells with nuclear binding of labeled galectin‐1 were basal and not suprabasal cells. Regarding proliferation, no relationship to the expression of a proliferation marker, Ki‐67, was observed. The nucleolar signal colocalized with fibrillarin and nucleophosmin/B23 as representatives of nucleolar proteins in both types of studied cells. In conclusion, the application of labeled galectins to localize accessible binding sites adds a new aspect to the functional analysis of these lectins in the nucleus.