bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low‐Melting, Low‐Viscous, Hydrophobic Ionic Liquids: 1‐Alkyl(Alkyl Ether)‐3‐methylimidazolium Perfluoroalkyltrifluoroborate
Authors: Zhou Zhi‐Bin , Matsumoto Hajime , Tatsumi Kuniaki 
Published: November 2004

AbstractA series of twenty two hydrophobic ionic liquids, 1‐alkyl(alkyl ether)‐3‐methylimidazolium ([Cmmim]+ or [CmOnmim]+; where Cm is 1‐alkyl, Cm=nCmH2m+1, m=1–4 and 6; CmOn is 1‐alkyl ether, C2O1=CH3OCH2, C3O1=CH3OCH2CH2, and C5O2=CH3(OCH2CH2)2) perfluoroalkyltrifluoroborate ([RFBF3]−, RF=CF3, C2F5, nC3F7, nC4F9), have been prepared and characterized. Some of the important physicochemical properties of these salts including melting point, glass transition, viscosity, density, ionic conductivity, thermal and electrochemical stability, have been determined and were compared with those of the reported [BF4]−‐based ones. The influence of the structure variation in the imidazolium cation and the perfluoroalkyltrifluoroborate ([RFBF3]−) anion on the above physicochemical properties was discussed. The key features of these new salts are their low melting points (−42 to 35 °C) or extremely low glass transition (between −87 and −117 °C) without melting, and considerably low viscosities (26–77 cP at 25 °C).
In Quest of Factors That Control the Enantioselective Catalytic Markovnikov Hydroboration/Oxidation of Vinylarenes
Authors: Segarra Anna M. , Daura‐Oller Elias , Claver Carmen , Poblet Josep M. , Bo Carles , Fernández Elena 
Published: November 2004

AbstractThis study attempts to rationalise the unpredictable performance of transition metal catalysed asymmetric hydroboration of vinylarenes on varying the precursor of the catalyst from cationic to neutral species, [M(cod)(L–L)]BF4, [M(μ‐Cl)(cod)]2/(L–L), the metal (M=Rh and Ir), and the hydroborating reagent (catecholborane, pinacolborane). The approaches are based on the agreement between experimental data provided by (R)‐Binap and (R)‐Quinap modified catalytic systems and computational data evidenced by DFT calculations and QM/MM strategies. Unprecedentedly high enantiomeric excesses in the hydroboration/oxidation of vinylarenes with both electron‐withdrawing substituents ((R)‐(+)‐1‐p‐F‐phenylethanol, ee up to 92 %) and electron‐releasing substituents ((R)‐(+)‐1‐p‐MeO‐phenylethanol, ee up to 98 %), can be attributed to a rhodium halide key intermediate.
First Detection of a Selenenyl Fluoride ArSeF by NMR Spectroscopy: The Nature of Ar2Se2/XeF2 and ArSeSiMe3/XeF2 Reagents
Authors: Poleschner Helmut , Seppelt Konrad 
Published: November 2004

AbstractArylselenenyl fluorides ArSeF are obtained from diselenides Ar2Se2 or arylselenotrimethylsilanes ArSeSiMe3, and XeF2. They are detected by low‐temperature 19F and 77Se NMR spectroscopy. Substitution in the ortho position of the aromatic ring to provide electronic or steric protection is a requirement for their formation. ArSeF compounds decompose according to 3 ArSeF→[ArSeSeF2Ar]+ArSeF→ArSeF3+Ar2Se2. Reaction energies for this disproportionation as well as that of the sulfur and tellurium homologues have been calculated with MP2, CCSD(T,) and B3 LYP methods. They were found to be increasingly exothermic in the sequence S<Se<Te. For selected SeC and SeF compounds the 77Se and 19F chemical shifts have been calculated by GIAO‐MP2 and GIAO‐B3 LYP methods and are in good agreement with experimental values.
Discrepancy between the Spin Distribution and the Magnetic Ground State for a Triaminoxyl Substituted Triphenylphosphine Oxide Derivative
Authors: Borobia Oscar Benedi , Guionneau Philippe , Heise Henrike , Köhler Frank H. , Ducasse Laurent , Vidal‐Gancedo Jose , Veciana Jaume , Golhen Stéphane , Ouahab Lahcène , Sutter Jean‐Pascal 
Published: November 2004

AbstractThe magnetic interaction and spin transfer via phosphorus have been investigated for the tri‐tert‐butylaminoxyl para‐substituted triphenylphosphine oxide. For this radical unit, the conjugation existing between the π* orbital of the NO group and the phenyl π orbitals leads to an efficient delocalization of the spin from the radical to the neighboring aromatic ring. This has been confirmed by using fluid solution high‐resolution EPR and solid state MAS NMR spectroscopy. The spin densities located on the atoms of the molecule could be probed since 1H, 13C, 14N, and 31P are nuclei active in NMR and EPR, and lead to a precise spin distribution map for the triradical. The experimental investigations were completed by a DFT computational study. These techniques established in particular that spin density is located at the phosphorus (ρ=−15×10−3 au), that its sign is in line with the sign alternation principle and that its magnitude is in the order of that found on the aromatic C atoms of the molecule. Surprisingly, whereas the spin distribution scheme supports ferromagnetic interactions among the radical units, the magnetic behavior found for this molecule revealed a low‐spin ground state characterized by an intramolecular exchange parameter of J=−7.55 cm−1 as revealed by solid state susceptibility studies and low temperature EPR. The X‐ray crystal structures solved at 293 and 30 K show the occurrence of a crystallographic transition resulting in an ordering of the molecular units at low temperature.
Novel Carbohydrate‐Appended Metal Complexes for Potential Use in Molecular Imaging
Authors: Storr Tim , Obata Makoto , Fisher Cara L. , Bayly Simon R. , Green David E. , Brudziñska Izabela , Mikata Yuji , Patrick Brian O. , Adam Michael J. , Yano Shigenobu , Orvig Chris 
Published: November 2004

AbstractSeven discrete sugar‐pendant diamines were complexed to the {M(CO)3}+ (99mTc/Re) core: 1,3‐diamino‐2‐propyl β‐D‐glucopyranoside (L1), 1,3‐diamino‐2‐propyl β‐D‐xylopyranoside (L2), 1,3‐diamino‐2‐propyl α‐D‐mannopyranoside (L3), 1,3‐diamino‐2‐propyl α‐D‐galactopyranoside (L4), 1,3‐diamino‐2‐propyl β‐D‐galactopyranoside (L5), 1,3‐diamino‐2‐propyl β‐(α‐D‐glucopyranosyl‐(1,4)‐D‐glucopyranoside) (L6), and bis(aminomethyl)bis[(β‐D‐glucopyranosyloxy)methyl]methane (L7). The Re complexes [Re(L1–L7)(Br)(CO)3] were characterized by 1H and 13C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L2)(CO)3Br] and [Re(L3)(CO)3Br], were characterized in the solid state by X‐ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L1–L7)(H2O)(CO)3]Br in aqueous conditions. Radiolabelling of L1–L7 with [99mTc(H2O)3(CO)3]+ afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.
Using Diffusion NMR To Characterize Guanosine Self‐Association: Insights into Structure and Mechanism
Authors: Kaucher Mark S. , Lam Yui‐Fai , Pieraccini Silvia , Gottarelli Giovanni , Davis Jeffery T. 
Published: November 2004

AbstractThis paper presents results from a series of pulsed field gradient (PFG) NMR studies on lipophilic guanosine nucleosides that undergo cation‐templated assembly in organic solvents. The use of PFG‐NMR to measure diffusion coefficients for the different aggregates allowed us to observe the influences of cation, solvent and anion on the self‐assembly process. Three case studies are presented. In the first study, diffusion NMR confirmed formation of a hexadecameric G‐quadruplex [G 1]16⋅4 K+⋅4 pic− in CD3CN. Furthermore, hexadecamer formation from 5′‐TBDMS‐2′,3′‐isopropylidene G 1 and K+ picrate was shown to be a cooperative process in CD3CN. In the second study, diffusion NMR studies on 5′‐(3,5‐bis(methoxy)benzoyl)‐2′,3′‐isopropylidene G 4 showed that hierarchical self‐association of G8‐octamers is controlled by the K+ cation. Evidence for formation of both discrete G8‐octamers and G16‐hexadecamers in CD2Cl2 was obtained. The position of this octamer–hexadecamer equilibrium was shown to depend on the K+ concentration. In the third case, diffusion NMR was used to determine the size of a guanosine self‐assembly where NMR signal integration was ambiguous. Thus, both diffusion NMR and ESI‐MS show that 5′‐O‐acetyl‐2′,3′‐O‐isopropylidene G 7 and Na+ picrate form a doubly charged octamer [G 7]8⋅2 Na+⋅2 pic− 9 in CD2Cl2. The anion's role in stabilizing this particular complex is discussed. In all three cases the information gained from the diffusion NMR technique enabled us to better understand the self‐assembly processes, especially regarding the roles of cation, anion and solvent.
Synthesis, Characterization, and Properties of Subporphyrazines: A New Class of Nonplanar, Aromatic Macrocycles with Absorption in the Green Region
Authors: Rodríguez‐Morgade M. Salomé , Esperanza Sagrario , Torres Tomás , Barberá Joaquín 
Published: November 2004

AbstractNovel subphthalocyanine analogues that display strong absorption in the green region have been synthesized by using a boron template cyclotrimerization of maleonitrile derivatives. The spectroscopic properties of these macrocycles indicate that, like subphthalocyanines, they have 14 π electrons and are aromatic compounds with a conical shape. The removal of the three fused benzene rings from the subphthalocyanine skeleton produces a 75–80 nm blue shift of the Q‐band and a slight lowering of the absorption coefficients for this band. In addition, the reduction of the π system from 18 to 14 electrons that accompanies progression from porphyrazines to subporphyrazines causes a hypsochromic shift of the Q‐band of around 100 nm. Subporphyrazines that are peripherally functionalized with six thioether chains, and in which the sulfur atoms are attached directly to the pyrrole moieties, exhibit optical features that may be explained in terms of the extension of π conjugation over the six thiolene groups, as well as strong π donation from the sulfur lone pairs to the macrocycle. These two effects are quantitatively and qualitatively very similar to those observed for porphyrazines that possess the same type of substitution. In addition, the mesomorphic behavior at low temperatures of a macrocycle that is substituted with six thiododecyl chains was demonstrated by using differential scanning calorimetry and optical polarising microscopy.
Long‐term results of high‐dose rate intracavitary brachytherapy for squamous cell carcinoma of the uterine cervix
Authors: Nakano Takashi , Kato Shingo , Ohno Tatsuya , Tsujii Hirohiko , Sato Shinichiro , Fukuhisa Kenjiro , Arai Tatsuo 
Published: November 2004

AbstractBACKGROUNDThe authors performed a long‐term follow‐up study to evaluate the efficacy and late toxicity of high‐dose rate intracavitary brachytherapy (HDR‐ICBT) for cervical carcinoma.METHODSFrom 1968 to 1986, 1148 patients with Stage IB to IVB squamous cell carcinoma of the cervix (staging was performed according to the International Federation of Gynecology and Obstetrics) were treated with a combination of external beam radiotherapy (EBRT) and HDR‐ICBT. For patients with early‐stage disease, 20 gray (Gy) of EBRT was delivered to the whole pelvis, followed by 24 Gy/4 fractions of HDR‐ICBT and 30 Gy of central‐shielding EBRT. For patients with advanced‐stage disease, 20–40 Gy of whole pelvic EBRT was administered, followed by 24 Gy/4 fractions of ICBT and 30–10 Gy of central‐shielding EBRT. The overall treatment time was approximately 6 weeks. Among survivors, the follow‐up rate was 98% and the median follow‐up duration was 22 years.RESULTSThe 10‐year pelvic tumor control rates were 93% for patients with Stage IB disease, 82% for patients with Stage II disease, and 75% for patients with Stage III disease. The 10‐year overall and cause‐specific survival rates were 74% and 89% for patients with Stage IB disease, 52% and 74% for patients with Stage II disease, and 42% and 59% for patients with Stage III disease, respectively. The 10‐year actuarial rates of major complications were 4.4% in the rectosigmoid colon, 0.9% in the bladder, and 3.3% in the small intestines.CONCLUSIONSThe results of the current study suggest that the combination of EBRT and HDR‐ICBT according to the authors' protocol provided outcomes that were comparable to those of the conventional low‐dose rate brachytherapy with acceptable rates of late complications in the treatment of cervical carcinoma. Cancer 2005. © 2004 American Cancer Society.
Assessing the feasibility of single lifetime PAP smear evaluation between 41–50 years of age as strategy for cervical cancer control in developing countries from our 32 years of experience of hospital‐based routine cytological screening
Authors: Misra Jata S. , Gupta Hem P. , Das Vinita 
Published: November 2004

AbstractIn view of the huge expenditure involved in mass cytological screening as well as lack of cytology manpower in the developing countries, single lifetime screening at 45 yr of age has been suggested as feasible strategy for control of cervical cancer. The present study is aimed at testing this hypothesis in a broader prospective, accommodating women between 41 and 50 yr of age from the data derived from the ongoing long‐term hospital‐based routine cervicovaginal cytology at Queen Mary's Hospital, Lucknow, India. The cervical smears of 31,032 women have been evaluated cytologically during a span of 32 yr (April 1971–March 2003) for early detection of carcinoma cervix and sexually transmitted diseases (STDs). The incidence of squamous intraepithelial lesions (SIL) was found to be 6.1% while frank malignancy was seen in 0.5% of cases. The following observations were made from the accumulated cytological data: (a) approximately 30% of the total cancer cases was in the age group of 41–50 yr; (b) the maximum number of SIL cases was detected in women between 41 and 50 yr of age (35% of the total SIL cases), and adequate management of these SIL cases would prevent cancer cases from occurring in later years, thus minimizing the maximum incidence of 1.3% observed in women beyond 50 yr of age; (c) the incidence of human papillomavirus (HPV) infection also was found quite high in women between 41 and 50 yr old, the adequate management of which would prevent onset/progression of any premalignant changes in the cervix.Our experience of 32 yr of cytological screening substantiates the hypothesis of single lifetime screening between 41 and 50 yr of age as an effective strategy for control of carcinoma cervix in developing countries like ours. Diagn. Cytopathol. 2004;31:376–379. © 2004 Wiley‐Liss, Inc.
Design and evaluation of an interface‐based naming system for supporting service synthesis in a ubiquitous computing environment
Authors: Minami Masateru , Morikawa Hiroyuki , Aoyama Tomonori 
Published: November 2004

AbstractThis paper considers the ubiquitous environment, in which a tremendous number of objects, such as physical devices, multimedia contents, and software components, exist everywhere. In order to provide and utilize various services transparently in such an environment, there must be a service synthesis technique that can dynamically construct services by mutually connecting objects. The realization of service synthesis requires a position‐independent naming service which can securely and transparently call from the network the functions (functional objects) that act as the service component. The authors designed an interface‐based naming service which can perform transparent calling of functional objects on the basis of interface information on the objects. The interface‐based naming service not only can call functional objects efficiently from the network, but also can provide several useful features of service synthesis support: when two functional objects are interconnected, the required supplementary functional object is automatically determined, and when a function cannot be found, that function is realized equivalently by using multiple functional objects. This paper describes the architecture of the interface‐based naming service, together with its algorithm. The approach is evaluated by simulation and it is shown that the interface‐based naming service is a useful system in a ubiquitous environment with an increased number of objects and an enlarged network scale. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(3): 63–75, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10177
A synchronization method deselecting candidate positions with chip level detection for optical CDMA
Authors: Iwata Ayako , Kamakura Koji , Sasase Iwao 
Published: November 2004

AbstractIn order to reduce the number of preamble bits required for synchronization at correct positions, a method of synchronization by deselecting the candidate positions for synchronization is proposed. As decision methods for each preamble bit, a method using the threshold detection and a method using chip level detection are discussed. Both methods make use of the fact that the preamble bit is the bit “1”: any synchronization position judged not to be a “1” bit even once is deselected as a candidate. In this way, the only position eventually remaining without being deselected is judged to be the synchronization position. As a result, it is possible to carry out synchronization with fewer preamble bits than the conventional method in which bit decision is based on the logarithmic likelihood ratio of the continuously transmitted preamble bits. A theoretical analysis is made under the assumption that the output of the photodetector follows a Poisson distribution. It is found that the proposed method can perform synchronization within a shorter time than the conventional synchronization method. Further, in the method using chip level detection, it is shown that synchronization is achieved in a shorter time even if the bit decision threshold is fixed. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(3): 21–32, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20160
Analysis of mutation spectra in UVB‐exposed mouse skin epidermis and dermis: Frequent occurrence of C→T transition at methylated CpG‐associated dipyrimidine sites
Authors: Ikehata Hironobu , Masuda Toshinari , Sakata Hiroyuki , Ono Tetsuya 
Published: November 2004

AbstractWe recently reported the kinetics of mutation induction by UVB in the skin epidermis and dermis of transgenic Muta™ mice [Ikehata and Ono, Mutat Res 508:41–47, 2002]. In the present study we determined the complete DNA sequence of the lacZ transgene in 208 mutants isolated from the dermis and epidermis of UVB‐irradiated and control mice. The resulting mutation patterns for the dermis and epidermis were similar, although two CC→TT tandem substitutions, one of the signature mutations for UV insult, were detected only among the UVB‐induced epidermal mutants. The spectra of the UVB‐induced and control mutations were both dominated by C→T transitions (83% and 62%); however, the C→T transitions from irradiated mice occurred almost exclusively in dipyrimidine sites, while those from control mice preferred CpG sites. Thus, the mutation spectrum detected for the irradiated skin tissues was different from the background spectrum and UV‐specific, confirming the utility of the transgenic system for UVB‐induced mutation studies in vivo. An analysis of the bases adjacent to the mutated cytosines from irradiated mice revealed that the dipyrimidine sites preferred for UVB‐induced mutation were 5′‐TC‐3′ > 5′‐CC‐3′ > 5′‐CT‐3′. Among mutants from irradiated mice, C→T transitions were recovered frequently at dipyrimidine sites associated with CpG. We showed that CpG sites in the lacZ transgene of Muta™ mice were heavily methylated in both the epidermis and dermis. Thus, CpG methylation could contribute to the UVB‐induced recurrent or hotspot mutations in the mammalian genome. Environ. Mol. Mutagen. 41:280–292, 2003. © 2003 Wiley‐Liss, Inc.
Activation of HLXB9 by juxtaposition with MYB via formation of t(6;7)(q23;q36) in an AML‐M4 cell line (GDM‐1)
Authors: Nagel Stefan , Kaufmann Maren , Scherr Michaela , Drexler Hans G. , MacLeod Roderick A. F. 
Published: November 2004

AbstractMutation or dysregulation of related homeobox genes occurs in leukemia. Using RT‐PCR, we screened members of the EHG family of homeobox genes, comprising EN1 (at 2q14), GBX2 (at 2q36), and EN2, GBX1, and HLXB9 (at 7q36), for dysregulation in acute myeloid leukemia (AML) cell lines indicated by chromosomal breakpoints at these sites. Only one EHG‐family gene was expressed, HLXB9, in cell line GDM‐1 (AML‐M4). Karyotypic analysis of GDM‐1 revealed a unique t(6;7)(q23;q35), also present in the patient. Fluorescence in situ hybridization analysis showed chromosomal breakpoints close to the region upstream of HLXB9, at 7q36, a region rearranged in certain AML patients, and at 6q23 upstream of MYB, a gene activated in leukemia. Detailed expression analysis suggested ectopic activation of HLXB9 occurred via juxtaposition with regions upstream of MYB, which was highly expressed in GDM‐1. Our data identified a cell line model for a novel leukemic translocation involving MYB with HLXB9, further implicating HLXB9 in leukemogenesis. © 2004 Wiley‐Liss, Inc.
Glial regulation of nonsynaptic extracellular glutamate in the substantia nigra
Authors: Rodríguez Díaz Manuel , Alonso Teofilo Jorge , Perdomo Diaz Juan , Gonzalez Hernández Tomás , Castro Fuentes Rafael , Sabate Magdalena , Garcia Dopico Jose 
Published: November 2004

AbstractGLU is the main neurotransmitter in the brain, where it induces a synaptic excitatory action. There is recent evidence for an extracellular nonsynaptic GLU (EnS‐GLU) pool in different brain nuclei that, released from glial cells, may act on extrasynaptic GLU receptors of cells located far from the position in which it was released. In the present work, the EnS‐GLU pool was studied with microdialysis in the rat substantia nigra (SN). We observed an EnS‐GLU pool that increased in a Ca2+‐dependent manner during cell depolarization. The selective alteration of with methionine sulfoximide (MSO) and fluorocitrate induced marked modifications in EnS‐GLU suggesting that EnS‐GLU is dependent on glial cells. Glutamine administration increased GLU, suggesting that neurons are also involved in EnS‐GLU modulation. GLU administered in the rostral SN showed a long‐distance diffusion to the caudal SN. The ionotropic GLU receptors agonist N‐methyl‐D‐aspartate and kainate and the metabotropic GLU receptors agonist ACPD increased EnS‐GLU and decreased extracellular glutamine. Taken together, these data indicate that nigral glia releases GLU, which probably performs a volume transmitter role. © 2004 Wiley‐Liss, Inc.