bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulation of Myc transactivation by the TATA binding protein in promoter-reporter assays
Authors: Barrett John F , Lee Linda A , Dang Chi V 
Published: May 2005

AbstractBackgroundThe c-Myc oncogenic transcription factor heterodimerizes with Max, binds specific DNA sites and regulates transcription. The role of Myc in transcriptional activation involves its binding to TRRAP and histone acetylases; however, Myc's ability to activate transcription in transient transfection assays is remarkably weak (2 to 5 fold) when compared to other transcription factors. Since a deletion Myc mutant D106-143 and a substitution mutant W135E that weakly binds TRRAP are still fully active in transient transfection reporter assays and the TATA binding protein (TBP) has been reported to directly bind Myc, we sought to determine the effect of TBP on Myc transactivation.ResultsWe report here a potent stimulation of Myc transactivation by TBP, allowing up to 35-fold transactivation of reporter constructs. Although promoters with an initiator (InR) element briskly responded to Myc transactivation, the presence of an InR significantly diminished the response to increasing amounts of TBP. We surmise from these findings that promoters containing both TATA and InR elements may control Myc responsive genes that require brisk increased expression within a narrow window of Myc levels, independent of TBP. In contrast, promoters driven by the TATA element only, may also respond to modulation of TBP activity or levels.ConclusionOur observations not only demonstrate that TBP is limiting for Myc transactivation in transient transfection experiments, but they also suggest that the inclusion of TBP in Myc transactivation assays may further improve the characterization of c-Myc target genes.
Gene expression profile of cervical tissue compared to exfoliated cells: Impact on biomarker discovery
Authors: Steinau Martin , Lee Daisy R , Rajeevan Mangalathu S , Vernon Suzanne D , Ruffin Mack T , Unger Elizabeth R 
Published: May 2005

AbstractBackgroundExfoliated cervical cells are used in cytology-based cancer screening and may also be a source for molecular biomarkers indicative of neoplastic changes in the underlying tissue. However, because of keratinization and terminal differentiation it is not clear that these cells have an mRNA profile representative of cervical tissue, and that the profile can distinguish the lesions targeted for early detection.ResultsWe used whole genome microarrays (25,353 unique genes) to compare the transcription profiles from seven samples of normal exfoliated cells and one cervical tissue. We detected 10,158 genes in exfoliated cells, 14,544 in the tissue and 7320 genes in both samples. For both sample types the genes grouped into the same major gene ontology (GO) categories in the same order, with exfoliated cells, having on average 20% fewer genes in each category. We also compared microarray results of samples from women with cervical intraepithelial neoplasia grade 3 (CIN3, n = 15) to those from age and race matched women without significant abnormalities (CIN1, CIN0; n = 15). We used three microarray-adapted statistical packages to identify differential gene expression. The six genes identified in common were two to four fold upregulated in CIN3 samples. One of these genes, the ubiquitin-conjugating enzyme E2 variant 1, participates in the degradation of p53 through interaction with the oncogenic HPV E6 protein.ConclusionThe findings encourage further exploration of gene expression using exfoliated cells to identify and validate applicable biomarkers. We conclude that the gene expression profile of exfoliated cervical cells partially represents that of tissue and is complex enough to provide potential differentiation between disease and non-disease.
Ataxia and peripheral nerve hypomyelination in ADAM22-deficient mice
Authors: Sagane Koji , Hayakawa Kazuhiro , Kai Junko , Hirohashi Tomoko , Takahashi Eiki , Miyamoto Norimasa , Ino Mitsuhiro , Oki Tohru , Yamazaki Kazuto , Nagasu Takeshi 
Published: May 2005

Abstract
Background
ADAM22 is a member of the ADAM gene family, but the fact that it is expressed only in the nervous systems makes it unique. ADAM22's sequence similarity to other ADAMs suggests it to be an integrin binder and thus to have a role in cell-cell or cell-matrix interactions. To elucidate the physiological functions of ADAM22, we employed gene targeting to generate ADAM22 knockout mice.

Results
ADAM22-deficient mice were produced in a good accordance with the Mendelian ratio and appeared normal at birth. After one week, severe ataxia was observed, and all homozygotes died before weaning, probably due to convulsions. No major histological abnormalities were detected in the cerebral cortex or cerebellum of the homozygous mutants; however, marked hypomyelination of the peripheral nerves was observed.

Conclusion
The results of our study demonstrate that ADAM22 is closely involved in the correct functioning of the nervous system. Further analysis of ADAM22 will provide clues to understanding the mechanisms of human diseases such as epileptic seizures and peripheral neuropathy.
Reactions of Air-Polluting Gases (NOx, SOx) with Transition Metal Cluster Complexes
Authors: Wakatsuki Yasuo , Chihara Teiji 
Published: May 2005

Abstract
As a molecular model for heterogeneous catalysis effected by fine metal particles, the reactions of NO, SO2, and SO with hexanuclear ruthenium clusters have been investigated in detail. One typical reaction of gaseous NO with anionic cluster is a redox-type reaction to give an one-electron oxidation product in which the original cluster framework is retained. The other typical reaction is observed in the reaction of neutral clusters with NO leading to partially degraded products, to which not only NO, but also an NO2 unit are coordinated. When a μ2,η3-allyl ligand is present in NO or SO2 coordinated hexanuclear carbonyl clusters, variable temperature 1H NMR spectra of the allyl terminal protons provide a good methodology to observe the fluxional behavior brought about by rapid migration of the NO and SO2 ligands over the metal atoms in the cluster core. Stepwise reduction of cluster-bound SO2 to SO and finally to S has been realized by the successive action of a Lewis acid and then CO or H2.
Electronic States and Magnetic Properties of Triplet Porphyrinato Copper(II) Cation Radical Complexes
Authors: Satoh Minoru , Ohba Yasunori , Hoshino Mikio , Konishi Shiro , Ebina Fujio , Yamauchi Seigo , Iwaizumi Masamoto 
Published: May 2005

Abstract
The porphyrinato copper cation radical complexes were examined by EPR spectroscopy. The cation radical complexes having bulky peripheral substituents are present as monomers in fluid solution and show EPR spectra due to intramolecular spin coupling between the spins on copper and on the porphyrin ring. The cation radical complexes, having no such substituents, form a dimer in solution. On the other hand, when they are oxidized in frozen solution by γ-ray irradiation, the cation radical complexes are always formed as a monomer, showing a triplet state EPR due to the intramolecular spin coupling. The zero field splitting and spin exchange parameters, |D| and 2J, obtained from EPR measurements were classified into two groups by their magnitudes. The tetraphenylporphyrinato copper(II) cation radical complex, [CuII(tpp)]+, has a small |D| and a small negative 2J value, while the octaethylporphyrinato copper(II) cation radical complex, [CuII(oep)]+, has a large |D| and a large negative 2J value. The other porphyrinato copper(II) cation radical complexes are classified into one of these two type of complexes. These classifications can be related to the electronic configuration of the porphyrin cation radicals. These |D| and 2J values also suggest that the triplet state monomer complexes of porphyrinato copper(II) cation must be deformed from the planar structure.
Systematic Enumeration of Ferrocene Derivatives by Unit-Subduced-Cycle-Index Method and Characteristic-Monomial Method
Authors: Fujita Shinsaku 
Published: May 2005

Abstract
The unit-subduced-cycle-index method and the characteristic-monomial method have been applied to the combinatorial enumeration of ferrocene derivatives. The enumeration has been itemized with respect to formulas as well as to symmetries, where the symmetry of each derivative is characterized by a factor group D∞h/C∞ and its subgroups. The chirality/achirality of ligands and of ferrocene derivatives has been discussed.
Physical Properties of Charge Transfer Salt (EDO-TTFBr2)2AsF6 in Mott Insulating State
Authors: Yoneyama Naoki , Miyazaki Akira , Enoki Toshiaki , Ogura Eiji , Kuwatani Yoshiyuki , Iyoda Masahiko 
Published: May 2005

Abstract
We have investigated the physical properties of a new charge transfer salt based on an asymmetric donor 4,5-dibromo-4′,5′-ethylenedioxy-tetrathiafulvalene (EDO-TTFBr2) whose crystal structure contains a weakly dimerized donor stacking structure. This salt is considered to be in a Mott insulating state in the vicinity of the metal-insulator boundary, taking account of the highly conductive semiconducting behavior and the feature of the susceptibility explained by the one-dimensional Heisenberg antiferromagnet model with an S = 1/2 localized spin per dimer and a large exchange interaction of about −190 K. The large exchange interaction and the exceptionally small resistivity (0.06 Ω cm at room temperature) originate from the strong inter-dimer transfer integral. The results of the ESR not only suggest an antiferromagnetic transition at 37 K, but also reflect the one-dimensional electronic state giving a negligible contribution to the spin-lattice relaxation process.
Laser Flash Photolysis Studies of the Photo-Ring-Opening Reaction of Flav-3-en-2-ol
Authors: Horiuchi Hiroaki , Yokawa Akinobu , Okutsu Tetsuo , Hiratsuka Hiroshi 
Published: May 2005

Abstract
Electronic structure and photodynamics of flav-3-en-2-ol have been studied by steady-state and time-resolved absorption measurements, and by semi-empirical MO calculations. The photo-ring-opening reaction to produce 2-hydroxychalcone has been determined to be a monophotonic process with the quantum yield of 0.29. The precursor to 2-hydroxychalcone has been assigned to the ground-state enol-form by nanosecond laser flash photolysis study at room temperature and steady-state photolysis study at 77 K. The efficiency of the tautomerization from the ground-state enol-form to keto-form of 2-hydroxychalcone has been estimated to be unity. The enol-form is transformed into 2-hydroxychalcone with the rate constant of 3.2 × 104 s−1 in neat acetonitrile, and this process is accelerated by protic molecules. The PM3 calculation of flav-3-en-2-ol showed that the dissociative potential surface in the first excited singlet-state is responsible for the ring-opening reaction.
Partition and Complex Formation of Alkali Metal Ions with Poly(oxyethylene) Derivatives in 4-Methyl-2-pentanone
Authors: Kikuchi Yoichi , Kubota Mitsuru , Sawada Kiyoshi 
Published: May 2005

Abstract
The partition equilibria of alkali metal picrates with or without a series of poly(oxyethylene) derivatives (POE compound, S) into 4-methyl-2-pentanone (MIBK) have been studied at 25.0 °C. The thermodynamic constants of the distribution and ion-pair formation in the water-saturated MIBK of ion pairs of alkali metal picrates (M+·Pic−), and , and the POE compounds-M+ complexes with Pic− (SM+·Pic−), and , were determined. From these data, the partition coefficients of M+ and Pic−, , and the thermodynamic formation constants of the POE compounds-M+ complexes in MIBK, , were evaluated. The interionic distances, a, of ion pairs were estimated from the ion-pair formation constants, and . These results were compared with those in an inert solvent, 1,2-dichloroethane (1,2-DCE). The complex formation constants, , in MIBK are much smaller than those in 1,2-DCE, and their differences among alkali metal ions are small. The donating ability of the solvent has large effects on the stability of the complexes, whereas the polarity (dielectric constant) of the solvent is not very effective. A small metal ion, particularly lithium ion, is strongly hydrated in water-saturated MIBK. Hydration to the lithium ion brings about a serious structural change in the POE compound complex.
Determination of Ultratrace Indium in Water Sample by Electrothermal Atomic Absorption Spectrometry after Preconcentration with Solvent Extraction and Back Extraction
Authors: Kawaguchi Hiroshi , Okamoto Takashi , Miura Keisuke , Shimizu Tokuo , Shirakashi Takashi 
Published: May 2005

Abstract
A method for the determination of indium at ng dm−3 levels in water sample is described. Indium is extracted into carbon tetrachloride as an ion pair of (5-sulfo-8-quinolinolato) indate(III) anion with tetradecyldimethylbenzylammonium chloride, and subsequently back-extracted into 0.3 cm3 of a nitric acid solution. The back-extracted solution, containing 100 μg cm−3 of palladium as a matrix modifier, is suitable for the determination of indium by electrothermal atomic absorption spectrometry. The extraction behavior of the ion associate was also compared with that of the 8-quinolinolato complex. The detection limit (3σ) for indium is 0.28 ng dm−3, based on a 2000-fold preconcentration. The proposed method is applicable to the determination of indium at ng dm−3 levels in water sample.
Thermal Isomerization of Silicon and Germanium Sesquichalcogenides, Thex4M4E6 (M = Si, Ge; E = S, Se)
Authors: Unno Masafumi , Ishii Daisuke , Matusmoto Hideyuki 
Published: May 2005

Abstract
The isomerization of the sesquichalcogenides Thex4M4E6 (Thex = 1,1,2-trimethylpropyl, 1: M = Si, E = S; 2: M = Si, E = Se; 3: M = Ge, E = S; 4: M = Ge, E = Se) with the “double-decker”-type structures (Thex2M2E2)2E2, (1dd—4dd) to the corresponding compounds with the adamantane-type structures Thex4M4E6 (1ad—4ad) was studied. The skeletal rearrangement has been observed to be reversible in the case of sesquichalcogenides 1, 2, and 4; for 1 and 4, the isomerization has reached an equilibrium with preference for adamantane-type structures 1ad and 4ad, respectively, while the equilibrium in 2 has lain more to “double-decker”-type 2dd. On the other hand, the isomerization of 3dd to 3ad has been observed to be irreversible under the condition employed. In the temperature ranges 433—453 K (1dd), 373—393 K (3dd), and 358—383 K (4dd), the equilibrium has followed reversible first-order kinetics. The thermodynamic parameters determined for the forward isomerization, the “double-decker”-type structures (dd) → adamantane-type structures (ad), are as follows: for 1dd → 1ad, Ea = 35.9 ± 0.1 kcal mol−1, ln A = 30.8 ± 0.2 s−1, ΔH‡ = 35.0 ± 0.1kcal mol−1, ΔS‡ = −0.044 cal mol−1 K−1; for 3dd → 3ad, Ea = 35.9 ± 0.1 kcal mol−1, ln A = 38.3 ± 0.2 s−1, ΔH‡ = 34.6 ± 0.1 kcal mol−1, ΔS‡ = 13.7 cal mol−1 K−1; for 4dd → 4ad, Ea = 32.3 ± 0.1 kcal mol−1, ln A = 35.7 ± 0.1 s−1, ΔH‡ = 31.7 ± 0.3 kcal mol−1, ΔS‡ = 10.4 cal mol−1 K−1. The X-ray structure of new sesquichalcogenide 2ad is also reported.
Ruthenium-Catalyzed Cyclopropanation of Norbornene with Propargyl Alcohol
Authors: Matsushima Yuji , Kikuchi Hidetoshi , Uno Mitsunari , Takahashi Shigetoshi 
Published: May 2005

Abstract
Norbornene as well as its 5,6-disubstituted derivatives and oxa-norbornene undergoes a novel cyclopropanation with propargyl alcohol in methanol containig cationic (η5-cyclopentadienyl)tris(acetonitrile)ruthenium complexes as catalysts to give exo-3-acetyltricyclooctane derivatives. Cyclopentadienylruthenium catalysts having an electron-withdrawing substituent on the Cp ligand exhibited the highest activity and the cyclopropanation proceeded even at −20 °C. On the basis of a deuterium labeling experiment, a reaction mechanism involving a ruthenacycle intermediate is proposed.
Total Synthesis of a Macrocyclic Antibiotic, Micrococcin P1
Authors: Okumura Kazuo , Suzuki Taishi , Nakamura Yutaka , Shin Chung-gi 
Published: May 2005

Abstract
The first total synthesis of a macrocyclic antibiotic, micrococcin P1 (1), was achieved. This antibiotic has a unique structure and is constructed of four components called Fragments A, B, C, and D. In particular, the structures of the central pyridine skeleton (Fragment A) and the exocyclic side-chain (Fragment D) of 1 are slightly different from those of a similar antibiotic, micrococcin P (2). By various chemical modifications of the synthetic method for 2, the synthesis of the central 2,3,6-tris(substituted thiazolyl)pyridine segment [Fragment A—C] 15 from ethyl 2-[6-dimethoxymethyl-2-(1-ethoxyvinyl)-3-pyridyl]thiazole-4-carboxylate (9), followed by coupling of 15 with the Fragments B and D moieties, synthesized independently, gave the protected Fragment A-B-C-D segment. Final intramolecular cyclization by using (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate as a condensing agent under high-dilution conditions and then deprotection of all the protecting groups with trifluoroacetic acid were effected successfully to give the expected synthetic 1.
Excimer Fluorescence of N-(1-Pyrenyl)iodoacetamide-Labeled Spectrin
Authors: Yamaguchi Takeo , Furukawa Yoichi , Terada Shigeyuki 
Published: May 2005

Abstract
The structure of spectrin in aqueous solutions or erythrocyte ghosts was characterized by using a fluorophore, N-(1-pyrenyl)iodoacetamide (NPIA). The excimer fluorescence of NPIA was clearly observed in isolated spectrin, but not in other proteins such as actin, bovine serum albumin, and lysozyme. The excimer disappeared upon addition of sodium dodecyl sulfate, but reappeared by dialysis. Further, the excimer appeared in spectrin extracts from ghosts labeled at 37 °C with NPIA. Interestingly, no such excimer in spectrin extracts appeared upon pretreatment of ghosts with diamide, and then N-ethylmaleimide. However, when such double-treated ghosts were exposed to dithiothreitol before NPIA labeling, the excimer fluorescence reappeared. Further, excimer fluorescence was observed in ghosts which were pretreated above 30 °C, especially at 50 °C, and then labeled at 0 °C with NPIA. The data of nondenaturing polyacrylamide gel electrophoresis and CD spectra showed marked changes in the structure of spectrin at 50 °C. We thus suggest that the excimer fluorescence of NPIA is useful to monitor the structural changes of spectrin.
1 : 2 Polycondensation of 3,3′,4,4′-Biphenyltetramine and 1,1′-Ferrocenedimethanol Catalyzed by [RuCl2(PPh3)3] to Give Polybenzimidazole Containing Ferrocenylene Groups
Authors: Yamaguchi Isao , Osakada Kohtaro , Yamamoto Takakazu , Katada Motomi 
Published: May 2005

Abstract
The 1 : 2 polycondensation of 3,3′,4,4′-biphenyltetramine and 1,1′-ferrocenedimethanol catalyzed by [RuCl2(PPh3)3] gives ferrocenylene-containing polybenzimidazole 1, (Im–Fc–CH2–O–CH2–Fc)n (Im = [5,5′-bi(benzimidazole)]-2,2′-diyl, Fc = 1,1′-ferrocenediyl). The reaction involves 1 : 2 condensation of 3,3′,4,4′-biphenyltetramine and 1,1′-ferrocenedimethanol to make two imidazole rings and subsequent intermolecular dehydrating coupling of two CH2OH groups to form the CH2–O–CH2 linkage. Polymer 1 is soluble in DMF and DMSO and has molecular weights, Mn = 2.1 × 104 and Mw = 4.5 × 104, determined by GPC (polystyrene standards). Extremely broad 1H NMR signals and results of SQUID measurements showing paramagnetism of 1 suggest the presence of Fe(III) centers in the polymer. The content of Fe(III) is estimated as approximately 20% based on the Mössbauer spectrum of 1. An equimolar reaction of 1,2-diaminobenzene and 1,1′-ferrocenedimethanol in the presence of the Ru(II) catalyst gives bis[1′-(benzimidazol-2-yl)ferrocen-1-ylmethyl] ether. The model compound shows reversible oxidation and reduction peaks assigned to the Fe(II)/Fe(III) redox, whereas the Polymer 1 undergoes oxidation and subsequent irreversible deprotonation to give the electrochemically inert polymer.
Calix[5]arene-Based Receptor for Dumb-Bell-Shaped C120
Authors: Haino Takeharu , Seyama Jun , Fukunaga Chigusa , Murata Yasujiro , Komatsu Koichi , Fukazawa Yoshimasa 
Published: May 2005

Abstract
We have developed calix[5]arene-based receptors for dumb-bell-shaped C120. The receptors encapsulate C120 with the high binding constants in o-dichlorobenzene.
Hydrophobic Vitamin B12. Part 20: Supernucleophilicity of Co(I) Heptamethyl Cobyrinate toward Various Organic Halides
Authors: Shimakoshi Hisashi , Maeyama Yasunori , Kaieda Takeshi , Matsuo Takashi , Matsui Eiki , Naruta Yoshinori , Hisaeda Yoshio 
Published: May 2005

Abstract
Heptamethyl cobyrinate, hydrophobic vitamin B12, was reduced to its Co(I) species by a reaction with sodium tetrahydroborate, which reacted with various organic halides, such as CH2Cl2, CHCl3, CCl4, CHBrCl2, CHBr3, CCl3CH3, CFCl3, and BrCH2CH2CH3, to form the corresponding alkylated complexes with dehalogenation. The alkylated complexes were characterized by elemental analyses and ESI-MS, and the photo-lability of the alkylated complexes was confirmed by the UV–vis absorption spectral change. The fashion for cleavage of the cobalt–carbon bond under irradiation with visible light was investigated by an ESR spin-trapping technique. The redox behavior of a series of alkylated complexes was investigated by cyclic voltammetry. The alkylated complexes showed an irreversible reduction peak at −1.21 to −1.29 V vs Ag–AgCl, which showed cleavage of the cobalt–carbon bond by electrolysis.
Arbutin Flow-Injection Analysis Using a Printed Circuit-Board Waste Modified Screen-Printed Electrode
Authors: Shih Ying , Zen Jyh-Myng , Senthil Kumar Annamalai , Huang Yu-Neng 
Published: May 2005

Abstract
A copper-metal enriched printed-circuit board waste modified screen-printed electrode has been demonstrated for the sensitive electroanalysis of a tyrosinase biosynthesis-inhibiting cosmetic agent, arbutin by flow-injection analysis.
Glycosyl Phosphonium Halide as a Reactive Intermediate in Highly α-Selective Glycosylation
Authors: Kobashi Yohei , Mukaiyama Teruaki 
Published: May 2005

Abstract
Highly α-selective glycosylations of several glycosyl acceptors with 2,3,4,6-tetra-O-benzyl-d-glucopyranosyl bromide (4) proceeded smoothly in the presence of tri(1-pyrrolidino)phosphine oxide in CH2Cl2 at room temperature or in refluxing CHCl3 via glycosyl phosphonium bromide intermediates and the corresponding disaccharides were afforded in good yields with high selectivities. Further, the one-pot glycosylation starting from glycosyl acetate using iodotrimethylsilane and phosphine oxide also proceeded efficiently in CH2Cl2 at room temperature to give the corresponding disaccharides, although this one-pot synthesis of α-glycoside via in situ anomerization procedure is considered difficult because glycosyl halide reacts with trimethylsilyl acetate easily to regenerate glycosyl acetate, a starting glycosyl donor.
Secondary Structural Studies of Biosynthetic Polypeptides with a Repeating Sequence of Glycine-Rich Sequence of Spider Dragling Silk
Authors: Fukushima Yasumasa , Nakajima Hiroshi 
Published: May 2005

Abstract
Polypeptides with a repeating sequence of glycine-rich sequence of spider dragline silk were synthesized in E. Coli. The polypeptide in the solid state formed a β-sheet structure which exists in crystalline region of spider silk.
Homogeneous Catalysis in Liquefied Gas. Complex-Catalyzed Selective and Direct Conversion of Propane to Butanal at Room Temperature
Authors: Sakakura Toshiyasu , Ishiguro Kouji , Okano Makoto , Sako Takeshi 
Published: May 2005

Abstract
Homogeneous catalysis in liquefied gas proves to be a promising approach to functionalize gaseous alkanes selectively; upon illumination, RhCl(CO)(PMe3)2 catalyzes carbonylation of liquefied propane at room temperature to produce butanal with high regioselectivity.