bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-6 and IL-8 release is mediated via multiple signaling pathways after stimulating dendritic cells with lysophospholipids
Authors: Öz-Arslan Devrim , Rüscher Wolfgang , Myrtek Daniel , Ziemer Mirjana , Jin Yixin , Damaj Bassam B , Sorichter Stephan , Idzko Marco , Norgauer Johannes , Maghazachi Azzam A 
Published: June 2006

AbstractLysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are bioactive lipid mediators, which are known to play major roles in allergic reactions as well as in tumor pathogenesis. Here, the biological activities and signal pathways of these lysophospholipids (LPLs) in dendritic cells (DCs) were characterized further. Flow cytometric and immunoblot analyses indicate that immature as well as mature DCs express the LPL receptors S1P1, S1P3, S1P5, and LPA2, but not S1P2, S1P4, LPA1, or LPA3. Moreover, enzyme-linked immunosorbent assay experiments demonstrate that simultaneous addition of these LPLs to immature DCs in the presence of lipopolysaccharide enhanced the secretion of the inflammatory cytokines interleukin (IL)-6 and IL-8 in maturing DCs. In contrast, no modification of IL-6 or IL-8 release was observed after exposure of mature DCs to LPLs alone. In addition, studies with pertussis toxin and mitogen-activated protein kinase (MAPK) kinase inhibitor PD98059 suggested that Gi proteins and MAPK pathway are involved in these LPL-induced cell responses. Corroborating these findings, we observed that LPLs induce the phosphorylation of extracellular signal-regulated kinase 1/2 in immature DCs but not in mature DCs. Further analyses show that inhibitors of phosholipase D, Rho, and protein kinase C also inhibited the LPL-induced release of IL-6 and IL-8. Therefore, our findings suggest that lipopolysaccharide in DCs uncouples LPL receptors from the signal-transducing machinery during maturation and that exposure of LPLs at early time-points to maturing DCs modifies the proinflammatory capacity of mature DCs.
Chemotherapy in Advanced Gastric Cancer: A Systematic Review and Meta-Analysis Based on Aggregate Data
Authors: Wagner Anna D. , Grothe Wilfried , Haerting Johannes , Kleber Gerhard , Grothey Axel , Fleig Wolfgang E. 
Published: June 2006

Purpose This systematic review and meta-analysis were performed to assess the efficacy and tolerability of chemotherapy in patients with advanced gastric cancer. Methods Randomized phase II and III clinical trials on first-line chemotherapy in advanced gastric cancer were identified by electronic searches of Medline, Embase, the Cochrane Controlled Trials Register, and Cancerlit; hand searches of relevant abstract books and reference lists; and contact to experts. Meta-analysis was performed using the fixed-effect model. Overall survival, reported as hazard ratio (HR) with 95% CI, was the primary outcome measure. Results Analysis of chemotherapy versus best supportive care (HR = 0.39; 95% CI, 0.28 to 0.52) and combination versus single agent, mainly fluorouracil (FU) -based chemotherapy (HR = 0.83; 95% CI = 0.74 to 0.93) showed significant overall survival benefits in favor of chemotherapy and combination chemotherapy, respectively. In addition, comparisons of FU/cisplatin-containing regimens with versus without anthracyclines (HR = 0.77; 95% CI, 0.62 to 0.95) and FU/anthracycline-containing combinations with versus without cisplatin (HR = 0.83; 95% CI, 0.76 to 0.91) both demonstrated a significant survival benefit for the three-drug combination. Comparing irinotecan-containing versus nonirinotecan-containing combinations (mainly FU/cisplatin) resulted in a nonsignificant survival benefit in favor of the irinotecan-containing regimens (HR = 0.88; 95% CI, 0.73 to 1.06), but they have never been compared against a three-drug combination. Conclusion Best survival results are achieved with three-drug regimens containing FU, an anthracycline, and cisplatin. Among these, regimens including FU as bolus exhibit a higher rate of toxic deaths than regimens using a continuous infusion of FU, such as epirubicin, cisplatin, and continuous-infusion FU.
Kinetics of Complexation between Cyclodextrin and Alcohol by Ultrasonic Relaxation Method: β-Cyclodextrin Solutions with 1-Butanol and 2-Methyl-2-propanol
Authors: Nishikawa Sadakatsu 
Published: June 2006

Abstract
The ultrasonic absorption coefficients over frequency range from 1.0 to 220 MHz were measured in aqueous β-cyclodextrin solutions with 1-butanol and 2-methyl-2-propanol at 25 °C. A clear single relaxational absorption with a relaxation frequency from 5 to 20 MHz was observed in a solution with 1-butanol, while the relaxational absorption was found in a lower frequency range in a solution with 2-methyl-2-propanol. The cause of the relaxation was attributed to a perturbation of a chemical equilibrium associated with complexation between β-cyclodextrin (host) and alcohol (guest). The rate and equilibrium constants for the complexation were determined from the concentration dependence of the relaxation frequency for the solution with 1-butanol. The standard volume change of the reaction was also obtained from the maximum absorption per wavelength. These results were compared with those for complexation between β-cyclodextrin and 1-propanol, and were considered in relation to the alcohol molecular structure. It was found that the rate of complex formation is almost independent of the guest molecule, and, therefore, the equilibrium constant for the complexation is controlled by the rate of departure of the guest molecule from the host. From this fact, the rate parameters for a solution with 2-methyl-2-propanol were estimated, and the calculated ultrasonic relaxation parameter was compared with the experimental data.
Membrane Phenomena in Nonisothermal Systems: Part 2. Effect of Hydrophobicity of Ion-Exchange Groups of Anion-Exchange Membranes on Thermoosmosis
Authors: Kiyono Ryotaro , Komoto Atsuhito , Tasaka Masayasu , Yamaguchi Takanori , Sata Toshikatsu 
Published: June 2006

Abstract
Solvent transport across poly(styrene)-based anion-exchange membranes with various ion-exchange groups was measured under a temperature gradient to discuss the effect of hydrophobicity of the membranes on thermoosmosis. Two varieties of poly(styrene)-based copolymer membranes with 10 and 14% divinylbenzene as cross-linking agent were prepared as base membranes. Benzyltrimethylammonium, benzyltriethylammonium, benzyltripropylammonium, benzyltributylammonium, and benzyltripentylammonium were introduced in the base membranes as anion-exchange groups. The thermoosmotic volume flux toward the hot solution side decreased with increasing the length of alkyl groups (increasing hydrophobicity of the groups), and at last, for the membranes with benzyltripentylammonium, the direction of thermoosmosis reversed: from the hot to the cold solution side as is observed for usual hydrophobic membranes. The transported energy and the mean transported entropy of water in the membranes estimated from the data of thermoosmosis and that of osmosis measurements increased with increasing the hydrophobicity of the ion-exchange groups introduced in the membranes.
Formation of Organic Compounds in Simulated Interstellar Media with High Energy Particles
Authors: Kasamatsu Takashi , Kaneko Takeo , Saito Takeshi , Kobayashi Kensei 
Published: June 2006

Abstract
Abiotic formation of amino acid precursors in interstellar dusts (ISDs) by cosmic radiation was quantitatively examined. In order to study the formation of organic compounds in ISDs, ice mixtures of carbon monoxide (or methane), ammonia, and water made in a cryostat at 10 K were irradiated with high energy protons. Irradiated ice products were warmed up to room temperature, while sublimed gases were analyzed with a quadrupole mass spectrometer. Some hydrocarbons and alcohols were detected. Amino acid precursors, which gave amino acids after acid-hydrolysis, were detected in non-volatile products remaining on the substrate at room temperature. G-values of glycine precursors from methanol, ammonia, and water in solid state irradiation were about 6 × 10−4, which was about two orders less than those in gasous state irradiation. The present results suggest that a considerable amount of organic compounds formed in extraterrestrial environments were supplied to the primitive earth before the origin of life.
Increased Redox-Reaction Rate of Quinhydrone at N-Substituted Polypyrrole Film Electrodes
Authors: Komura Teruhisa , Kobayashi Tomohiro , Yamaguti Takahiro , Takahasi Kousin 
Published: June 2006

Abstract
A poly[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium] perchlorate-coated glassy carbon electrode noticeably decreased the charge-transfer resistance (Rt) of quinhydrone relative to a naked glassy carbon electrode. The redox species was not concentrated into a polymer film; this result differs markedly from the very good absorption of anthraquinonesulfonates and indigosulfonates by a polymer film. The dependence of Rt and the interfacial capacitance on the film thickness implies that the charge-transfer process occurs at the film-solution interface, because the polymer film is appreciably electronically conductive at positive potentials. Because of a change in the film conductivities with the potential, the polymer-coated electrode increased the anodic peak current of quinhydrone by three times, but decreased its cathodic peak current by two fifths, relative to that of a naked electrode. Although the decrease in Rt at a polymer-film electrode is somewhat ascribed to an increasing area, which is due to a porous film surface, the electrocatalytic effect of the polymer film can be attributed to an increasing standard rate constant of the charge-transfer process; this increase may be due to the adsorption of quinhydrone on the polymer surface.
Cooperative Redox Regulation of [4Fe-4S] Ferredoxin Model Arenethiolate Complexes by NH···S Hydrogen Bonds and an Aromatic C–H···S Interaction
Authors: Ueno Takafumi , Inohara Masahiro , Ueyama Norikazu , Nakamura Akira 
Published: June 2006

Abstract
A series of the model complexes containing ortho-substituted arenethiolato ligands, ((Et4N)2[Fe4S4(S-2-RCONHC6H4)4] {R = Ph (1), 4-MeO–C6H4 (2), and 4-F–C6H4 (3)} and (Et4N)2[Fe4S4{S-2,6-(RCONH)2C6H3}4] {R = Ph (4), 4-MeO–C6H4 (5), and 4-F–C6H4 (6)}) was synthesized and characterized by 1H NMR, IR spectroscopy, and cyclic voltammetry. The solution structures of these complexes are discussed based on their 1H NMR T1 data and molecular-dynamics calculations. Complex 4 has a shorter distance (av. 4.3 Å) between the protons of the benzoyl group and the inorganic sulfur atom of the [4Fe-4S] cluster than the corresponding ones of 1 (av. 6.2 Å). These results indicate the C–H···S interaction between the protons of the benzoyl group and the sulfur atom of the [4Fe-4S] cluster. The [Fe4S4(SAr)4]2−/[Fe4S4(SAr)4]3−redox potential for 1 and 4 are −0.86 and −0.65 V, respectively. The difference between 1 and 4 is Δ0.21 V. This is larger than the value Δ0.11 V between [Fe4S4(S-2-t-BuCONHC6H4)4]2− (−0.91 V) and [Fe4S4{S-2,6-(t-BuCONH)2C6H3}4]2− (−0.80 V), considered to be the difference between singly and doubly NH··&middotS hydrogen-bonded complexes. The redox potentials for 1—6 follow the trend of the Hammett σm values, showing that the aromatic ring of the benzoyl group interacts with the [4Fe-4S] cluster directly. A cooperative effect between the C–H···S interaction and the NH···S hydrogen bond is thus found to regulate the redox potential of the model complexes.
Preparation and Stereochemistry of Cobalt(III) Complexes Containing 2,2′-Bipyridine 1,1′-Dioxide
Authors: Kanno Hideaki , Yano Takahiro , Sato Katsumi , Utsuno Shunji , Fujita Junnosuke 
Published: June 2006

Abstract
New cobalt(III) complexes, [Co(N4)(bpdo)]3+ (N4 = (en)2, (tn)2, (NH3)4, and tren; bpdo = 2,2′-bipyridine 1,1′-dioxide) and [Co(en)2(rac-3,3′-Me2bpdo)]3+ (rac-3,3′-Me2bpdo = racemic3,3′-dimethyl-2,2′-bipyridine 1,1′-dioxide), were obtained, where tn and tren denote trimethylenediamine and 2,2′,2″-triaminotriethylamine, respectively. The [Co(en or tn)2(bpdo)]3+ and [Co(en)2(rac-3,3′-Me2bpdo)]3+ complexes form only one of two possible racemic pairs of diastereomers, which were resolved by SP-Sephadex column chromatography. Each pair of these complexes was assigned to have a lel(Δ(λ), Λ(δ)) structure on the basis of the 13C NMR and circular dichroism spectra, and the absolute configuration of optically active free 3,3′-Me2bpdo ligand recovered from the resolved complex. The tetraammine and tren complexes were resolved into a pair of enantiomers by a chemical method, but rapidly racemized in water with the rate of 7.33 × 10−3 s−1 and 1.16 × 10−3 s−1, respectively, at 10.0 °C. An intramolecular conformational inversion of the skew bpdo chelate ring (δ λ) was proposed for the racemization.
Formation and Conversion of Yellow Molybdophosphonate Complexes in Aqueous-Organic Media
Authors: Ueda Tadaharu , Sano Ken-ichi , Himeno Sadayuki , Hori Toshitaka 
Published: June 2006

Abstract
The reaction of Mo(VI) with PHO32− in acidic solution containing CH3COCH3 or CH3CN led to the formation of the previously unknown 15-molybdobis(phosphonate) complex. The addition of an excess of PHO32− caused 15-molybdobis(phosphonate) to transform into 16-molybdotetrakis(phosphonate) in the CH3COCH3–water system. In the CH3CN–water system, on the other hand, the spontaneous transformation of 15-molybdobis(phosphonate) into 12-molybdobis(phosphonate) occurred in the presence of an excess of PHO32− or at greater acidities; the latter complex was also formed in aqueous media. The yellow heteropolyanions underwent electrochemical reductions, yielding mixed-valence blue species.
Evidence for Spiro-Conjugation in Perpendicularly-Linked Pentamethinestreptocyanine Dimers
Authors: Katoh Takashi , Ogawa Keizo , Inagaki Yoshio , Okazaki Renji 
Published: June 2006

Abstract
Perpendicularly-linked pentamethinestreptocyanine dimers (1) in which the two cyanine moieties are linked at the center carbon atoms of the methine chains were prepared. The absorption spectra of 1 in solution showed two peaks at 446 and 406 nm, which are attributed to the splitting of the HOMO levels through spiro-conjugation between the two cyanine moieties, as calculated from the INDO/S-CI method. The reduction potential of 1 positively shifted with respect to that of the corresponding monomer (2). The oxidation polarogram of 1 showed two waves, with the first potential negatively shifting compared to that of 2.
Synthesis and Properties of Dimethyl- and Monomethylbis(phosphite)palladium(II) Complexes
Authors: Kayaki Yoshihito , Shimizu Isao , Yamamoto Akio 
Published: June 2006

Abstract
New dimethylpalladium complexes having alkyl and aryl phosphites as the supporting ligands, cis-[PdMe2{P(OR)3}2] (R = Me, 1a; Ph, 1b), have been prepared by two routes, (1) by the reaction of [Pd(acac)2] with [AlMe2(OEt)] in the presence of the phosphite ligands, and (2) by the ligand exchange reaction of [PdMe2(cod)] (COD = 1,5-cyclooctadiene) with two molar amounts of the phosphites. Monomethylpalladium chloride complexes, [PdMe(Cl){P(OR)3}2] (R = Me, 2a; Ph, 2b; Pri, 2c) have been prepared by ligand exchange reaction of [PdMe(Cl)(cod)] with two molar amounts of the phosphites, whereas [PdMe(OAc){P(OR)3}2] (R = Me, 3a; Ph, 3b) has been synthesized by treatment of 1 with acetic acid. Strong influence of the coordinated phosphite ligand on the cis or trans configuration of the monomethylpalladium complexes was observed, the results being in contrast with those of complexes having the trimethylphosphine ligands that give preferentially trans complexes. Removal of the chloride ligand in 2 with an equimolar amount of AgBF4 or treatment of the dimethylpalladium complex 1 with HBF4 in the expectation of obtaining a bis(phosphite)-coordinated complex led to formation of a mixture of the tris(phosphite) complex, [PdMe{P(OR)3}3]+BF4− and the mono-phosphite complex [PdMe{P(OR)3}(s)2]+BF4− (s = solvent), presumably through the rapid disproportionation of an unstable intermediate [PdMe{P(OR)3}2(s)]+BF4−.
Reduction of Methemoglobin via Electron Transfer across the Bilayer Membrane of Hb Vesicles
Authors: Takeoka Shinji , Ohgushi Takeru , Nishide Hiroyuki , Tsuchida Eishun 
Published: June 2006

Abstract
The hemoglobin vesicle (HbV) has a cellular structure which encapsulates concentrated Hb in the inner aqueous phase of a phospholipid bilayer vesicle. Hb is gradually autoxidized to methemoglobin (metHb), which can not bind oxygen during oxygen transport under physiological conditions. In order to reduce metHb in HbV, we evaluated the reduction of metHb by electron transfer across the bilayer membrane of HbV from a reductant added to the outer aqueous phase. Water-soluble methylene blue (MB) and hydrophobic ubiquinone 10 (UQ) were selected as electron mediators. Under a nitrogen atmosphere, the addition of the reduced form nicotinamide-adenine dinucleotide (NADH) to the outer aqueous phase of UQ-incorporated HbV showed only a slow reduction rate for metHb. On the other hand, when MB and NADH were added under a nitrogen atmosphere to HbV containing 40% metHb, a rapid decrease in the metHb percentage was observed. The entire reaction was controlled by a reaction with NADH and MB in the outer aqueous phase. Under aerobic conditions, the decrease in the efficiency of the metHb reduction and rapid oxidation after reaching the minimal metHb percentage were observed. This was confirmed to be due to the influence of hydrogen peroxide; the decrease was prevented by the co-encapsulation of catalase.
Mechanism of a Chain-Extending Reaction in the Synthesis of Segmented Poly(urethane–urea) Using Blocked Ethylenediamine
Authors: Nakano Yasuhiro , Yamazaki Emiko , Hanahata Hiroyuki , Okajima Kunihiko , Kitahama Yoshiharu 
Published: June 2006

Abstract
An attempt was made to clarify the mechanism of a chain-extending reaction of NCO-terminated prepolymers in the synthesis of segmented poly(urethane–urea) using blocked ethylenediamine (EDA) with acetone (ACE). For this purpose, an ACE/EDA mixture was allowed to react with phenyl isocyanate (PhNCO) as a model of the prepolymer. The reaction of PhNCO with the ACE/EDA mixture, which was proved to contain ketimine and imidazolidine compounds by NMR measurements, gave 1,1′-ethylenebis[3-phenylurea] (M-Ur-1) as the main product; at the same time 1,3-diphenylurea (1,3-DPU) was assumed to be formed as a side-reaction product between PhNCO and H2O, inevitably existing in the mixture as the result of condensation. From a considerable increase in the yield of M-Ur-1 upon the addition of an excess amount of H2O to the reaction system, H2O was elucidated to participate in the acceleration of the main reaction, giving M-Ur-1 as well as in the side reaction, yielding 1,3-DPU. The excess H2O added to the system might preferentially facilitate the former reaction, rather than the latter.
Gels of Bis[1,2-bis(3,4-di-n-alkoxyphenyl)ethanedione dioximato]palladium(II) Complexes
Authors: Ohta Kazuchika , Moriya Mitsuo , Ikejima Mayumi , Hasebe Hiroshi , Kobayashi Nagao , Yamamoto Iwao 
Published: June 2006

Abstract
Bis[1,2-bis(3,4-di-n-alkoxyphenyl)ethanedione dioximato]palladium(II) complexes (abbreviated as [Pd{(CnO)4dpg}2]; n = 7—12) form gels in an over-concentrated n-hexane solution. We have developed a specific cell for X-ray diffraction in order to determine the gel structure. The gel has a two-dimensional hexagonal structure which is similar to the inverted hexagonal phase of lyotropic liquid crystals. The electronic spectra were measured for the gel and for a chloroform solution, which dose not form a gel. As a result, it has become apparent that a 4dz2–5pz intermolecular charge-transfer transition between the neighboring palladium ions is the main driving force of the gel formation. The circular dichroism and magnetic circular dichroism of the gel suggested that this complex has a stack of left-handed helicity. The complex also has a thermotropic liquid-crystalline state, as previously reported. Hence, these three kinds of states are closely related to each other in terms of the formation of molecular aggregates.
A Novel Crosslinking–Decrosslinking System of Polymers Having Spiro Orthoester Moieties in the Side Chains
Authors: Endo Takeshi , Suzuki Takashi , Sanda Fumio , Takata Toshikazu 
Published: June 2006

Abstract
Acid-catalyzed reversible crosslinking–decrosslinking of polymers having spiro orthoester groups in the side chains was carried out. The copolymers obtained by the radical copolymerizations of 2-methylene-1,4,6-trioxaspiro[4.6]undecane with acrylonitrile, methyl, cyclohexyl, and 2-ethylhexyl acrylates were treated with trifluoroacetic acid (5 mol%) at −10 °C for 1 h in CH2Cl2 (4.2 M) to afford the crosslinked polymers in 69—99% yields. The crosslinked polymers were then treated with trifluoroacetic acid at a low concentration (0.1 M) in CH2Cl2 at room temperature for 1 h to give the original polymers in 55—99% yields. These results strongly support the conclusion that the acid-catalyzed reversible crosslinking–decrosslinking of the polymers possessing the spiro orthoester groups in the side chains could be constructed.
Ultrafast Spectroscopy with Broad Probe Spectral Range Extending from Near Ultraviolet to Near Infrared
Authors: Kobayashi Takayoshi 
Published: June 2006

Abstract
A broad-band femtosecond spectroscopy apparatus has been developed. The spectrum of the probe light pulse extends from 400 nm to 3.0 μm, covering near ultraviolet (NUV), visible (VIS), and near infrared (NIR) ranges. The time resolution is better than 100 fs in the NUV and VIS regions, and better than 200 fs in the NIR region. The minimum detectable absorbance change is 2 × 10−3 for wavelengths between 400 nm and 1.6 μm and 3 × 10−3 between 1.6 μm and 3.0 μm. A tunable light pulse for the pump was also developed using the second-harmonic generation (SHG) and sum-frequency generation (SFG) in the cavity of the optical parametric oscillator. The tuning ranges of SHG and SFG are 529—585 nm and 426—483 nm, respectively. The study of ultrafast geometrical relaxation processes in a substituted poly(phenylacetylene) by the use of the broad spectroscopy apparatus is described as an example at the end.
Synthesis of S2−- and PF2O2-Bridged Dinuclear Ruthenium(IV) Complex Obtained from the Reaction of Disulfide-Bridged Ruthenium(III) Dimer Complex with Dioxygen and Water
Authors: Matsumoto Kazuko , Sano Yoichi , Kawano Masaki , Uemura Hiroyuki , Matsunami Jun , Sato Toshio 
Published: June 2006

Abstract
Reaction of [{Ru(CH3CN)3[P(OMe)3]2}2(μ-S2)](PF6)3 with a mixture of acetylene and O2 gave a novel ruthenium(IV) dimer complex [{Ru(IV)(PFO3)[P(OMe)3]2}2(μ-S)(μ-PF2O2)2]. The newly formed bridging and terminal ligands PF2O2− and PFO32− are produced from the reaction of PF6− with trace amounts of H2O in the solvent. Although acetylene is not incorporated in the final product, it is necessary to accelerate the reaction. Ruthenium(IV) complexes with S2− ligand are rare and only two examples are previously known. The crystal of [{Ru(PFO3)[P(OMe)3]2}2(μ-S)(μ-PF2O2)2] is monoclinic, space group P21/n, a = 11.061(5), b = 20.764(4), c = 17.074(3) Å, β = 95.74(2)°, V = 3901(1) Å3, and Z = 4. The bridging PF2O2− ligand coordinates to Ru atoms with the two oxygen atoms, while the terminal PFO32− ligand coordinates to a Ru atom with one of the oxygen atoms. The molecular structure is confirmed by 31P and 19F NMR spectroscopy.