bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Series of Vanadium‐Sulfite Polyoxometalates: Synthesis, Structural, and Physical Studies
Authors: Miras Haralampos N. , Raptis Raphael G. , Lalioti Nikolia , Sigalas Michael P. , Baran Peter , Kabanos Themistoklis A. 
Published: February 2005

AbstractReaction of NH4VO3 with sulfur dioxide affords the hexanuclear cluster (NH4)2(Et4N)[(VIVO)6(μ4‐O)2(μ3‐OH)2(μ3‐SO3)4(H2O)2]Cl⋅H2O (1), and the decapentanuclear host–guest compound (Et4N)5{Cl⊂ [(VO)15(μ3‐O)18(μ‐O)3]}⋅3 H2O (2). Sequential addition of magnesium oxide to an acidic aqueous solution of NH4VO3 (pH≈0) followed by (NH4)2SO3 resulted in the formation of either the non‐oxo polymeric vanadium(IV) compound trans‐(NH4)2[VIV(OH)2(μ‐SO3)2] (3) or the polymeric oxovanadium(IV) sulfite (NH4)[VIVO(SO3)1.5(H2O)]⋅2.5 H2O (4) at pH values of 6 and 4, respectively. The decameric vanadium(V) compound {Na4(μ‐H2O)8(H2O)6}[Mg(H2O)6][V${{{{\rm V}\hfill \atop 10\hfill}}}$(O)8(μ6‐O)2(μ3‐O)14]⋅3 H2O (5) was synthesised by treating an acidic aqueous solution of NH4VO3 with MgO and addition of NaOH to pH≈6. All the compounds were characterised by single‐crystal X‐ray structure analysis. The crystal structure of compound 1 revealed an unprecedented structural motif of a cubane unit [M4(μ4‐O)2(μ3‐OH)2] connected to two other metal atoms. Compound 3 comprises a rare example of a non‐oxo vanadium(IV) species isolated from aqueous solution and in the presence of the reducing agent SO32−, while compound 4 represents a rare example of an open‐framework species isolated at room temperature (20 °C). In addition to the synthesis and crystallographic studies, we report the IR and magnetic properties (for 1, 2 and 3) of these vanadium clusters as well as theoretical studies on compound 3.
Synthetic Fragments of Antigenic Lipophosphoglycans from Leishmania major and Leishmania mexicana and Their Use for Characterisation of the Leishmania Elongating α‐D‐Mannopyranosylphosphate Transferase
Authors: Higson Adrian P. , Ross Andrew J. , Tsvetkov Yury E. , Routier Françoise H. , Sizova Olga V. , Ferguson Michael A. J. , Nikolaev Andrei V. 
Published: February 2005

AbstractThe phosphorylated branched heptasaccharides 7 and 8, the octasaccharide 9 and the phosphorylated trisaccharides 5 and 6, which are fragments of the phosphoglycan portion of the surface lipophosphoglycans from Leishmania mexicana (5) or L. major (6–9), were synthesised by using the glycosyl hydrogenphosphonate method for the preparation of phosphodiester bridges. The compounds were tested as acceptor substrates/putative inhibitors for the Leishmania elongating α‐D‐mannosylphosphate transferase.
Removal of Fluorine from and Introduction of Fluorine into Polyhalopyridines: An Exercise in Nucleophilic Hetarenic Substitution
Authors: Bobbio Carla , Rausis Thierry , Schlosser Manfred 
Published: February 2005

AbstractStarting from six industrially available fluorinated pyridines, an expedient access to all three tetrafluoropyridines (2–4), all six trifluoropyridines (5–10), and the five non‐commercial difluoropyridines (11–14 and 16) was developed. The methods employed for the selective removal of fluorine from polyfluoropyridines were the reduction by metals or complex hydrides and the site‐selective replacement by hydrazine followed by dehydrogenation–dediazotation or dehydrochlorination–dediazotation. To introduce an extra fluorine atom, a suitable precursor was metalated and chlorinated before being subjected to a chlorine/fluorine displacement process.
Testing the robustness of CIECAM02
Authors: Li C. J. , Luo M. R. 
Published: January 2005

AbstractCIE TC8‐01 has adopted a new color appearance model: CIECAM021 replaces the CIECAM97s.2 The new model consists of a number of refinements and simplifications of the CIECAM97s color appearance model. This article describes further tests to the robustness of the forward and reverse modes. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 99–106, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20087
Role of p53 status in chemosensitivity determination of cancer cells against histone deacetylase inhibitor sodium butyrate
Authors: Joseph Jeena , Wajapeyee Narendra , Somasundaram Kumaravel 
Published: February 2005

AbstractHistone deacetylases inhibitors (HDIs) induce growth arrest and apoptosis in a variety of human cancer cells. Sodium butyrate (NaB), a histone deacetylase inhibitor, has been shown to cause a G1 cell cycle arrest by inducing p21WAF1/CIP1 in a p53‐independent manner. In this report, we present evidence for activation of p53 pathway by NaB and its role in the NaB‐mediated growth suppression. Addition of NaB increased the levels of p53 involving a p14ARF‐dependent post‐transcriptional mechanism. NaB induced p53 is functional as it activated p53‐specific reporter, induced the level of p21WAF1/CIP1, inhibited cellular DNA synthesis and induced apoptosis. By using HPV 16 E6 stable transfectants as well as p53 null cancer cells, we show that NaB suppresses the growth of WT p53 containing cells more efficiently. NaB inhibited DNA synthesis to similar extent both in the presence and absence of p53. However, NaB treatment lead to a major G2/M arrest of cells in the presence of p53, while cells without wild‐type p53 accumulated mainly in G1 phase of the cell cycle. Furthermore, apoptosis induction by NaB is greatly reduced in the absence of p53. These results suggest that p53 pathway mediates in part growth suppression by NaB and the p53 status may be an important determinant of chemosensitivity in HDI based cancer chemotherapy. © 2005 Wiley‐Liss, Inc.
Myxoid liposarcoma FUS‐DDIT3 fusion oncogene induces C/EBP β‐mediated interleukin 6 expression
Authors: Göransson Melker , Elias Erik , Ståhlberg Anders , Olofsson Anita , Andersson Carola , Åman Pierre 
Published: February 2005

AbstractThe myxoid/round cell liposarcoma oncogene FUS‐DDIT3 is the result of a translocation derived gene fusion between the splicing factor FUS and DDIT3. In order to investigate the downstream targets of DDIT3, and the transforming effects of the FUS‐DDIT3 fusion protein, we have introduced DDIT3‐GFP and FUS‐DDIT3‐GFP constructs into a human fibrosarcoma cell line. The gene expression profiles of stable transfectants were compared to the original fibrosarcoma cell line by microarray analysis. We here report that the NFκB and C/EBP β controlled gene IL6 is upregulated in DDIT3‐ and FUS‐DDIT3‐expressing fibrosarcoma cell lines and in myxoid liposarcoma cell lines. Strong expression of the tumor associated multifunctional cytokine interleukin 6 was confirmed both at mRNA and protein level. Knockdown experiments using siRNA against CEBPB transcripts showed that the effect of FUS‐DDIT3 on IL6 expression is C/EBP β dependent. Chromatin immunoprecipitation revealed direct interaction between the IL6 promoter and the C/EBP β protein. In addition, the effect of DDIT3 and FUS‐DDIT3 on the expression of other acute phase genes was examined using real‐time PCR. We demonstrate for the first time that DDIT3 and FUS‐DDIT3 show opposite transcriptional regulation of IL8 and suggest that FUS‐DDIT3 may affect the synergistic activation of promoters regulated by C/EBP βκB. © 2005 Wiley‐Liss, Inc.
Epidemiologic and viral factors associated with cervical neoplasia in HPV‐16‐positive women
Authors: Rajeevan Mangalathu S. , Swan David C. , Nisenbaum Rosane , Lee Daisy R. , Vernon Suzanne D. , Ruffin Mack T. , Horowitz Ira R. , Flowers Lisa C. , Kmak David , Tadros Talaat , Birdsong George , Husain Mujtaba , Srivastava Sudhir , Unger Elizabeth R. 
Published: February 2005

AbstractWhile infection with high‐risk HPV is the most important risk factor for cervical cancer, HPV alone is insufficient. Our purpose was to identify viral and epidemiologic factors associated with cervical disease in HPV‐16 DNA‐positive women referred to colposcopy. We used a standardized interview to collect epidemiologic data from consenting women. Total nucleic acids from exfoliated cervical cells were used for all viral assays (HPV detection and typing using L1 consensus PCR with line probe hybridization, variant classification by sequencing, viral load and transcript copy determination by quantitative PCR and transcript pattern by nested RT‐PCR). Cervical disease was based on colposcopic biopsy. Logistic regression was used to calculate ORs with 95% CIs. There were 115 HPV‐16 positive women among 839 enrollees. By univariate analyses, age >25 years (OR = 3.05, 95% CI 1.20–7.76), smoking (OR = 3.0, 95% CI 1.19–7.56), high viral load (OR = 5.27, 95% CI 2.05–13.60), detection of both E6 and E6*I transcripts (OR = 10.0, 95% CI 2.1–47.58) and high transcript copies (OR = 5.56, 95% CI 2.05–13.60) were significant risk factors for CIN III with reference to No CIN/CIN I. Less than a third of the women (31.5%) had prototype HPV‐16 detected, and variants showed no association with disease, viral load or transcription. Viral DNA and transcript copies were highly correlated, and the ratio of transcript copies to DNA copies was not changed with disease status. While viral load, transcript copies and transcript pattern were statistically associated with CIN III, none of these measures effectively discriminated between HPV‐16 women with disease requiring treatment and those who could be followed. Cellular proliferation and differentiation pathways affected by HPV should be investigated as biomarkers for cervical cancer screening. © 2005 Wiley‐Liss, Inc.
Determination of arginine in dietary supplements
Authors: Gange Michelle E , Francis Paul S , Costin Jason W , Barnett Neil W , Lewis Simon W 
Published: February 2005

AbstractWe present a rapid and sensitive flow injection method for the determination of arginine in dietary supplements. Detection was based on the chemiluminescence reaction of arginine with alkaline hypobromite. The response is proportional to analyte concentration over the calibration range, from 2.5 × 10−6 to 1 × 10−4 M, and a relative standard deviation of 1% was calculated (1 × 10−5 M, n = 12). Samples required only aqueous dilution prior to analysis, and over 100 samples could be analysed per hour, which is superior to that achieved with conventional colorimetric and enzymatic procedures. The results obtained with the flow injection methodology were concordant with those achieved using high‐performance liquid chromatography employing pre‐column derivatisation and fluorescence detection. Copyright © 2005 Society of Chemical Industry
Ethephon‐induced fractional changes of pectic polysaccharides in developing cape gooseberry (Physalis peruviana L) fruits
Authors: Majumder Kausik , Mazumdar Bibhas C 
Published: February 2005

AbstractPectic polysaccharides extracted from fruit tissue of cape gooseberry (Physalis peruviana L) at different maturity levels were fractionated and analyzed for galacturonic acid backbone molecules. Preharvest spray of the fruits at 7 days old with ethephon resulted in a higher accumulation of water‐soluble and oxalate‐soluble pectic fractions than non‐treated fruits, while this treatment effectively enhanced the polygalacturonase enzyme activity necessary for maintenance of pectin degradation. Treatment with ethephon not only enhanced the solubilization rate but also resulted in a net increase in total pectic polymer content in developing cape gooseberry fruits. Copyright © 2005 Society of Chemical Industry
In vitro procedure to predict apparent antioxidant release from wholegrain foods measured using three different analytical methods
Authors: Nagah Abdulbaset M , Seal Chris J 
Published: February 2005

AbstractSeveral methods have been applied to the measurement of antioxidants in biological samples. Extraction methods have previously relied on chemical methods which are non‐physiological. This paper reports the use of an in vitro method with enzymatic and fermentation steps, designed to mimic digestion through the gastrointestinal tract, on release of antioxidants from a range of wholegrain foods. A total of 41 samples, (31 raw foods, 10 of which were also analysed after cooking) were analysed using the ferric reducing antioxidant capacity and Trolox equivalent antioxidant capacity methods. Six samples were also measured using the oxygen radical absorption capacity method. The three antioxidant assay methods gave different apparent antioxidant activity trends, and the range of values was dependent on the type of food. The effects of cooking were mainly observed in the early stages of the incubation procedure, suggesting that cooking may destroy soluble antioxidants but not those bound within the food matrix. For all samples, apparent antioxidant release increased during the incubation period, suggesting that antioxidants bound within the food matrix may be released and exert their effects in different regions of the gastrointestinal tract. Copyright © 2005 Society of Chemical Industry
An NMR investigation of the importance of intramolecular hydrogen bonding in determining the conformational equilibrium of ethylene glycol in solution
Authors: Petterson Krag A. , Stein Robin S. , Drake Michael D. , Roberts John D. 
Published: February 2005

AbstractAlthough conformational analysis by NMR of ethylene glycol indicates generally strong preferences for the gauche conformation in solvents ranging from water to chloroform, the bulk of the NMR evidence indicates that intramolecular hydrogen bonding between the hydroxyl groups is unlikely to be a significant factor in determining that preference, except possibly in fairly non‐polar solvents. The ‘gauche effect’ is clearly very important, especially in aqueous solution. Copyright © 2005 John Wiley & Sons, Ltd.
Amino acid coupling patterns in thermophilic proteins
Authors: Liang Han‐Kuen , Huang Chia‐Mao , Ko Ming‐Tat , Hwang Jenn‐Kang 
Published: February 2005

AbstractStructural analysis is useful in elucidating structural features responsible for enhanced thermal stability of proteins. However, due to the rapid increase of sequenced genomic data, there are far more protein sequences than the corresponding three‐dimensional (3D) structures. The usual sequence‐based amino acid composition analysis provides useful but simplified clues about the amino acid types related to thermal stability of proteins. In this work, we developed a statistical approach to identify the significant amino acid coupling sequence patterns in thermophilic proteins. The amino acid coupling sequence pattern is defined as any 2 types of amino acids separated by 1 or more amino acids. Using this approach, we construct the ρ profiles for the coupling patterns. The ρ value gives a measure of the relative occurrence of a coupling pattern in thermophiles compared with mesophiles. We found that thermophiles and mesophiles exhibit significant bias in their amino acid coupling patterns. We showed that such bias is mainly due to temperature adaptation instead of species or GC content variations. Though no single outstanding coupling pattern can adequately account for protein thermostability, we can use a group of amino acid coupling patterns having strong statistical significance (p values < 10−7) to distinguish between thermophilic and mesophilic proteins. We found a good correlation between the optimal growth temperatures of the genomes and the occurrences of the coupling patterns (the correlation coefficient is 0.89). Furthermore, we can separate the thermophilic proteins from their mesophilic orthologs using the amino acid coupling patterns. These results may be useful in the study of the enhanced stability of proteins from thermophiles—especially when structural information is scarce. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Coherent control of the biexciton in a single quantum dot
Authors: Flissikowski T. , Betke A. , Akimov I. A. , Henneberger F. 
Published: February 2005

AbstractWe report on coherent control of the two‐photon transition between the ground state and the biexciton state on a single quantum dot level. The population of the biexciton is monitored by the cascaded spontaneous emission of the biexciton complex via the exciton states. The signal shows interference pattern at the double laser frequency and its contrast decays non‐exponentially at the time scale of 10 ps. The contrast decrease is attributed to a dynamical inhomogeneous broadening of the energy levels due to long‐term fluctuations in the dot environment. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum dot VCSELs
Authors: Ustinov Victor M. , Maleev Nikolai A. , Kovsh Alexey R. , Zhukov Alexey E. 
Published: February 2005

AbstractMolecular beam epitaxy growth of InAs/InGaAs QD structures on GaAs substrates as well as fabrication and performance of long‐wavelength QD edge‐emitting lasers and VCSELs are discussed. 1.3 µm QD VCSELs were successfully fabricated from the structures with several QD planes inserted into the optical microcavity with AlO–GaAs and AlGaAs–GaAs Bragg reflectors. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy partitioning in association processes
Authors: Carvalho Alexandre R. F. , Melo André 
Published: February 2005

AbstractIn this work, the partition method introduced by Melo and Ramos has been extended to enable the decomposition of the stabilization energies associated with molecular association processes into physical meaningful components (conformational rearrangement, nonbonding, bonding, and polarization plus charge transfer). This partition scheme, within a semiempirical formalism, enables a complete separability of the above‐mentioned components. The molecular system has also been partitioned into perturbed and bulk regions, defined as flexible variable‐size entities. This procedure enables one to evaluate the range of the perturbation originated by an association process. Several association processes (covalent and noncovalent) have been studied using this methodology. The results obtained enable us to conclude that the current decomposition scheme can be used for understanding the cohesive phenomena. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Reporting small Δ17O values: existing definitions and concepts
Authors: Assonov S. S. , Brenninkmeijer C. A. M. 
Published: February 2005

AbstractThe three‐isotope tracer Δ17O is increasingly used in atmospheric chemistry and other research areas. Thanks to the development of isotope‐ratio mass spectrometry (IRMS), δ17O and δ18O can be determined with a precision of a few 0.01‰, and values for Δ17O may be calculated with similar precision. However, interpreting small and precisely determined Δ17O values as a deviation from an expected mass‐dependent fractionation process is not straightforward. Several aspects are of high importance. In the present paper we review existing definitions, formulas and some other aspects of Δ17O reporting. One of the most confusing aspects is a variance of definitions and corresponding formulas. While Δ17O is traditionally defined to characterise a data point, i.e. Δ17O is considered as a deviation from an expected mass‐fractionation line, the recently introduced definition (Miller MF. Geochim. Cosmochim. Acta 2002; 66: 188) characterises a fractionation line itself, in terms of its ordinate intercept. The formulas corresponding to this definition gives a characteristic for a specific process. When the ‘traditionally defined’ Δ17O is in use, an expected fractionation processes—the key point for Δ17O reporting—should be defined and parameterised with the same accuracy as intended for reporting Δ17O. When Δ17O is reported for a data point, not only a value for λ but an ordinate intercept of a reference fractionation line should be given with high accuracy. We note that defining a single fractionation process is hardly possible for many natural compounds. For such compounds we propose to use a phenomenological reference line, namely an isotope composition range of natural sources. Next, aspects of Δ17O comparison and mass‐balance calculations are considered. All the aspects considered for Δ17O may be relevant for others three‐isotope tracers, e.g. Δ33S. Copyright © 2005 John Wiley & Sons, Ltd.
Investigation on the performance of space‐time block coded ultrawide band communication systems
Authors: Du Yinggang , Tai Chan Kam 
Published: February 2005

AbstractUltrawide band (UWB) communication systems show many advantages over the conventional narrow band systems. In this paper, three UWB systems at the same transmission efficiency are investigated. The first one is a conventional system with only one transmit antenna (non‐STBC). The second one is combined with the space‐time block coding (STBC) over one symbol (STBC‐1). The third system is combined with the STBC over two symbols (STBC‐2), which is in accordance with Almouti's scheme. Both theoretical analysis and simulations show that the STBC‐1 system performs the best. In addition, the adoption of the normalized modified Hermite polynomial based orthogonal pulses (NMHP) instead of the Gaussian pulse (GP) to represent theM‐ary symbol constellation can increase the data rate and lead to an improvement of the signal to noise ratio (SNR) by about 10log10MdB at the bit error rate (BER) of 10−4at any symbol constellation for any UWB system. The simulations in both flat‐fading channels and frequency‐selective channels have confirmed such improvement. Copyright © 2005 John Wiley & Sons, Ltd.
Offset‐stack scheme and receivers for CCC‐based multicarrier CDMA architecture
Authors: Huang Aiping , Li Jing , Liu Shao‐Bo 
Published: February 2005

AbstractThe main objective of this paper is to present new receiver structures to improve the applicability of a recently developed multicarrier CDMA architecture based on complete complementary codes. A mathematical description of the new system is presented in this paper. It is found that though it is the offset‐stack scheme that guarantees high spectral efficiency and scalable rate‐matching, error propagation under multipath fading noisy channel conditions is generated due to such special spreading modulation scheme and the corresponding recursive receiver. In order to avoid error propagation, the precondition of multipath replica separation is derived mathematically so that a non‐recursive receiver can be employed. The range of the channel delay spread is discussed and the impact of the time shift in offset‐stack spreading modulation on spectral efficiency is analyzed. Then, a RAKE receiver is proposed to further improve the performance through multipath diversity. Simulations are carried out under multipath fading noisy channel conditions to further verify the theoretical analysis. Performance loss caused by error propagation is observed by comparing the performances of the recursive receiver and the non‐recursive receiver. With the same spectral efficiency, the proposed offset‐stack scheme and the RAKE receiver gain obvious performance improvement compared to the existing offset‐stack scheme and the recursive receiver. Copyright © 2005 John Wiley & Sons, Ltd.