bluuebunny/crossref_metadata_2025_split huggingface dataset:
Propiononitrile as an Extraction Solvent for the Ion-Pair Complexes of Water-Soluble Tetracationic Porphyrinatocopper(II) with Perchlorate: The Effect of Sodium Chloride
Authors: Fujii Kenta , Nishimoto Jun , Yamada Shiro , Fukamachi Mizue , Tabata Masaaki 
Published: March 2004

Abstract
The ion-pair extraction of 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrinatocopper(II) ([CuII(tmpyp)]4+, CuP4+) with perchlorate ion has been studied for a water–propiononitrile (PN) system in the presence of sodium chloride. The [CuII(tmpyp)]4+ was extracted as [CuP·4ClO4] and dissociated to [CuP·2ClO4]2+ and [CuP·ClO4]3+ in the PN phase. The high concentration of NaCl in the aqueous phase suppressed the extraction of [CuP·nClO4](4−n)+ (n = 1, 2) due to the increased partition of ClO4− into the PN phase. The extraction constants of [CuII(tmpyp)]4+ with ClO4− into the PN phase at different concentrations of NaCl were found to be KexKdis1Kdis2Kdis3 (mol−1 dm3) = [CuP·ClO43+]o[ClO4−]o3[CuP4+]a−1[ClO4−]a−4 = 9.1 ± 1.9, (3.0 ± 0.2) × 10−1, and (2.5 ± 2.2) × 10−1 for 0, 0.5, and 1.0 mol dm−3 NaCl, respectively, and KexKdis1Kdis2 (mol−2 dm6) = [CuP·2ClO42+]o[ClO4−]o2[CuP4+]a−1[ClO4−]a−4 = 31 ± 18 for 1.0 mol dm−3 NaCl. The extraction constants of NaClO4 were found to be Kex(NaClO4) (mol−1 dm3) = [NaClO4]o[Na+]a−1[ClO4−]a−1 = (8.8 ± 1.6) × 10−2 and (5.1 ± 0.7) × 10−2 for 0.5 and 1.0 mol dm−3 NaCl, respectively. The dissociation constants of NaClO4 in the PN phase were determined: Kdis(NaClO4) (mol dm−3) = [Na+]o[ClO4−]o[NaClO4]o−1 = (1.5 ± 0.3) × 10−2 and (2.8 ± 0.4) × 10−2 for 0.5 and 1.0 mol dm−3 NaCl, respectively, and Kex(NaClO4)Kdis(NaClO4) = [Na+]o[ClO4−]o[Na+]a−1[ClO4−]a−1 = (2.37 ± 0.05) × 10−3 for 0 mol dm−3 NaCl. The detailed extraction mechanism of [CuII(tmpyp)]4+ is discussed by taking into account the chemical species of [CuP·nClO4](4−n)+ in the PN phase and the extraction of NaClO4 and comparing these with the results obtained for acetonitrile.
Preparation and Characterization of an α-Keggin-Type [SW12O40]2− Complex
Authors: Himeno Sadayuki , Takamoto Masayo , Hoshiba Mitsuru , Higuchi Ayumi , Hashimoto Masato 
Published: March 2004

Abstract
A divanadium-substituted derivative of 12-tungstosulfate(VI), [S(V2W10)O40]4− was prepared as the tetrabutylammonium (n-Bu4N+) salt by heating a 50 mM (M = mol dm−3) W(VI)–20 mM V(V)–0.5 M H2SO4–50% (v/v) CH3CN system at 70 °C for 24 h. The [S(V2W10)O40]4− anion was transformed spontaneously into a monovanadium-substituted derivative, [S(VW11)O40]3− in a 70% (v/v) CH3CN–1.0 M HCl system at 70 °C. On the other hand, [SW12O40]2− was precipitated as the n-Bu4N+ salt upon heating a 95% (v/v) CH3CN–0.5 M HCl system containing [S(V2W10)O40]4−. The single-crystal X-ray structural analysis revealed that the structure consisted of an α-Keggin-type [SW12O40]2− anion. The [SW12O40]2− anion was characterized by IR and UV–vis spectroscopy, and voltammetry.
A High-Throughput Screening Assay of Endocrine-Disrupting Chemicals Using a Receptor-Modified Au-Electrode
Authors: Murata Masaharu , Yano Kentaro , Fukuma Kaori , Maeda Mizuo , Katayama Yoshiki 
Published: March 2004

Abstract
There is a great deal of concern that wildlife and human health have been adversely affected by anthropogenic chemicals that can disrupt normal endocrine homeostasis. In order to identify the binding ability of chemicals to human estrogen receptors (hER), we have constructed a biosensor which carries the hER ligand-binding domain on the surface. The receptor was expressed as an in-frame fusion with ten consecutive histidine residues using a bacterial system, and then the recombinant protein was immobilized on an Au-electrode via Ni(II)-mediated chemisorption using the histidine tag and thiol-modified nitrilotriacetic acid. This receptor-modified electrode was used to define the binding capacity of several xenoestrogens and anti-estrogen to the hER. The biosensor showed a linear response to the chemicals in a concentration-dependent manner. The order of the detection limits was: 17β-estradiol (10−10 M) &gt; diethylstilbestrol (DES; 10−8 M), ICI 182780 (10−8 M), dibutyl phthalate (10−8 M), bisphenol A (10−8 M) &gt; p-nonylphenol (10−6 M), testosterone (10−6 M). Compared to the traditional binding assay, our method has the advantage of being more feasible, due to the high-throughput screening assay for evaluating the binding ability of chemicals to the receptors.
Blue Phosphorescence of the Novel Dinuclear Gold(I) Complex Bridged by 1,3-Benzenedithiolate in Solution
Authors: Watase Seiji , Kitamura Takayuki , Hasegawa Yasuchika , Kanehisa Nobuko , Nakamoto Masami , Kai Yasushi , Yanagida Shozo 
Published: March 2004

Abstract
A novel dinuclear benzenedithiolatogold(I) complex was synthesized and characterized spectroscopically. This complex showed intense blue emission [quantum yield at 1.0 × 10−4 mol dm−3: Φ = 0.026(2)] at room temperature in fluid solvents. This emission originates from a metal-perturbed ligand-centered transition. The relatively long life time of the excited state (τ50 = ca. 2 μsec) and the large stokes shift suggest that the emission is phosphorescence. The X-ray single crystal structural determination showed that the complex has a distorted 12-membered macrocyclic structure bridged by two benzenedithiolate ligands, with no gold–gold interactions.
Cytotoxic Antifeedant from Dionaea muscipula Ellis: A Defensive Mechanism of Carnivorous Plants against Predators
Authors: Tokunaga Takashi , Dohmura Atsushi , Takada Noboru , Ueda Minoru 
Published: March 2004

Abstract
We revealed that Dionaea muscipula Ellis accumulates a great amount of cytotoxic naphthoquinone derivatives, of which the main component is plumbagin (1). It was also revealed that 1 showed strong antifeedant activity against Spodoptera litura. These results strongly suggest that 1 in D. muscipula operates as an antifeedant which prevents them from being consumed by predators. The accumulation of a great amount of 1 would be an important strategy of carnivorous plants for their survival. Also, we discuss the structure–activity relationship of the cytotoxicity of naphthoquinones using isolated naphthoquinones and their derivatives.
How Does Lipase Flexibility Affect Its Enantioselectivity in Organic Solvents? A Possible Role of CH···π Association in Stabilization of Enzyme–Substrate Complex
Authors: Watanabe Keiichi , Uno Tetsuya , Koshiba Takashi , Okamoto Takashi , Ebara Yasuhito , Ueji Shin-ichi 
Published: March 2004

Abstract
For lipase-catalyzed reactions of 2-(4-substitued phenoxy)propionic acids with alcohols in organic solvents containing a small amount of water, the increase of the lipase flexibility brought about by addition of water is found to be favorable for the induced-fit motion of the lipase for the correctly binding enantiomer of the substrate used, thus resulting in the improvement of the lipase enantioselectivity. In particular, for the reaction of the substrate with rich π electron density on its aromatic ring, the enantioselectivity was much more sensitive to the change of the lipase flexibility. Thus, in the induced fit motion, the CH···π association between amino acids side chains around the lipase’s active site and the aromatic ring of the correctly binding enantiomer is assumed to accelerate the accommodation of the substrate into the lipase’s active site and the stabilization of the complex between the enzyme and the substrate. This assumption is also supported by a discussion based on the value of the Michaelis constant obtained. Furthermore, on the basis of a model concerning the acyl-enzyme structure for the incorrectly binding enantiomer, the long alkyl chain alcohols as a nucleophile are found to improve the lipase enantioselectivity markedly.
Chemoselective Reduction of α,β-Unsaturated Aldehydes, Ketones, Carboxylic Acids, and Esters with Nickel Boride in Methanol–Water
Authors: Khurana Jitender Mohan , Sharma Purnima 
Published: March 2004

Abstract
A facile procedure for the conjugate reduction of α,β-unsaturated aldehydes, ketones, carboxylic acids, and esters is reported with nickel boride generated in situ from NiCl2·6H2O/NaBH4 in methanol–water at ambient temperature.
An Efficient Synthesis of 2,4-Disubstituted Quinolines by Electrophile-Mediated Cyclization Reactions of 2-Isocyanostyrene Derivatives
Authors: Kobayashi Kazuhiro , Takagoshi Kenichi , Kondo Shizuka , Morikawa Osamu , Konishi Hisatoshi 
Published: March 2004

Abstract
A novel quinoline synthesis starting with 2-isocyanostyrene derivatives is described. The treatment of 2-isocyanostyrene derivatives with aldehydes (or acetone) in the presence of a catalytic amount of diethyl ether–boron trifluoride afforded quinoline derivatives carrying a 1-hydroxyalkyl substituent at the 2-position. The use of acetaldehyde diethyl acetal or phenyloxirane as an electrophile under the same conditions gave the corresponding quinoline derivatives, carrying the 1-ethoxyethyl or 2-hydroxy-2-phenylethyl substituent at the 2-position, respectively. 2-Isocyanostyrene derivatives reacted with N,N-dimethyliminium salts without any catalyst to give 2-(1-dimethylaminoalkyl)quinolines.
Chiral 2,2′-Binaphthyldiimine–Nickel(II) Complexes as Lewis Acid Catalysts for Enantioselective Diels–Alder Reactions
Authors: Suga Hiroyuki , Kakehi Akikazu , Mitsuda Masashi 
Published: March 2004

Abstract
The preparation and application of a novel class of chiral Lewis acid catalysts based on chiral 2,2′-binaphthyldiimine ligands are described. Among the binaphthyldiimine–metal complexes tested, N,N′-bis(2-quinolylmethylene)-1,1′-binaphthyl-2,2′-diamine–Ni(II) complex was found to be an efficient chiral Lewis acid catalyst for asymmetric Diels–Alder reactions (endo: up to 96% ee) between cyclopentadiene and 3-alkenoyl-2-oxazolidinones. This catalyst is easy to prepare and is efficient; that is, 1 mol% of the Ni(II) catalyst promoted a Diels–Alder reaction between cyclopentadiene and 3-acryloyl-2-oxazolidinone smoothly with high enantioselectivity (endo: 90% ee).
Flavin Receptors. Effects of Melamine Derivatives Bearing Thiourea and Thiouronium Ion on the Binding and Reactivity of Flavin Mimics in Chloroform
Authors: Watanabe Shigeki , Kosaka Naoki , Kondo Shin-ichi , Yano Yumihiko 
Published: March 2004

Abstract
Melamine derivatives bearing thiourea and thiouronium ion were prepared as flavin receptors. The binding modes of the receptors for flavin mimics were evaluated from the binding constants and 1H NMR data in chloroform. The effects of the receptors on the oxidation of N-benzyl-1,4-dihydronicotinamide (BNAH) and benzenethiol by flavin mimics were kinetically investigated in chloroform.
Radical Cyclization of O-Pentafluorobenzoyloximes Having a (Cyclohexadiene)Fe(CO)3 Moiety
Authors: Tanaka Kenichi , Yukimura Noriaki , Narasaka Koichi 
Published: March 2004

Abstract
In the presence of atmospheric oxygen, O-pentafluorobenzoyloximes having a (2,4-cyclohexadienyl)Fe(CO)3 moiety at the α-position cyclize smoothly to give trans-fused [(4,5,6,7-η)-3a,7a-dihydro-3H-indole]Fe(CO)3 complexes. The cyclization proceeds via radical chain mechanism initiated by molecular oxygen, in which pentafluorobenzoyloxyl radical plays a role as a chain carrier. Thus obtained trans-fused dihydroindole iron complexes readily isomerize to the cis-fused isomers on acidic silica gel or under basic conditions. Such isomers are converted to 3a,7a-dihydroindole or indole derivatives by the oxidative removal of the Fe(CO)3 group.
Silica-Based Mesostructured Materials Induced by Surfactant Assemblies in the Two-Dimensionally Limited Space of a Layered Polysilicate Kanemite
Authors: Kimura Tatsuo , Itoh Daigo , Shigeno Tetsuro , Kuroda Kazuyuki 
Published: March 2004

Abstract
Silica-based mesostructured materials derived from a layered polysilicate kanemite were prepared by reactions with gemini-type diammonium (C16–3–16, C16–5–16, C16–3–1) surfactants. The surfactants were assembled in the two-dimensionally limited space between the silicate layers of kanemite, leading to the formation of lamellar, 2-d hexagonal, and disordered mesophases. Lamellar phases were formed by using C16–3–16 and C16–5–16 surfactants. An acid treatment of the lamellar C16–5–16–silicate complex induced the transformation into a 2-d hexagonal phase, whereas the C16–3–16–silicate complex retained its lamellar structure after the treatment. A disordered phase was obtained through the reaction of kanemite with C16–3–1 surfactants whose assembly shows a larger surface curvature. The formation of layered surfactant–silicate intermediates under various conditions and the transformation to other mesophases lead to the conclusion that the formation of ordered and disordered mesostructured materials derived from kanemite simply depends on the surfactant assemblies in the two-dimensionally limited space.
Thermal Dehydration of a Poly(vinyl alcohol) Film Promoted by Diphenyliodonium Trifluoromethanesulfonate: Absorption Spectra and Elemental Analysis Results
Authors: Yamamoto Yukio , Tagawa Seiichi 
Published: March 2004

Abstract
The thermal dehydration of poly(vinyl alcohol) (PVA) films containing diphenyliodonium trifluoromethanesulfonate (Ph2I+Tf−) was investigated in the temperature range of 150 to 190 °C by absorption spectroscopy and elemental analysis. The dehydration was greatly promoted in the presence of Ph2I+Tf−, which is known to be a thermally stable photoacid generator. The oxidation of thermally generated PVA radicals, α-hydroxyalkyl type radicals, by Ph2I+Tf− is considered to lead to the dehydration by cationic reactions. The dehydration yield, calculated from the elemental analysis results, became highest at 170 °C. A lowering of the dehydration yields at the higher temperatures, 180 and 190 °C, has been attributed to an elimination of the volatile H+Tf− from the films, resulting in the disappearance of the cationic intermediates participating in the dehydration.
Comparison of UV–Vis Changes Observed in Deprotonation of 2-Heptylbenzimidazole, 2-Heptyl-4,7-diphenylbenzimidazole, and Poly(2-heptylbenzimidazole-4,7-diyl)
Authors: Tanimoto Akitoshi , Shiraishi Kouichi , Yamamoto Takakazu 
Published: March 2004

Abstract
Shifts of the UV–vis peak caused by deprotonation of 2-heptylbenzimidazole and sterically strained 2-heptyl-4,7-diphenyl-benzimidazole and poly(2-heptylbenzimidazole-4,7-diyl) (P[4,7-Bim(Hep)]) are discussed. The π–π* absorption band of the strained molecules showed a large shift to a longer wavelength on deprotonation with NaOH. P[4,7-Bim(Hep)] showed a new absorption peak at about 400 nm.
The fate of augments to treat type-2 bone defects in revision knee arthroplasty
Authors: Patel J. V. , Masonis J. L. , Guerin J. , Bourne R. B. , Rorabeck C. H. 
Published: March 2004

We report the five- to-ten year results of Anderson Orthopaedic Research Institute type-2 bone defects treated with modular metal augments in revision knee surgery. A total of 102 revision knee arthroplasties in patients with type-2 defects treated with augments and stems were prospectively studied. Seven patients (seven knees) had incomplete follow-up and 15 patients (16 knees) died with the arthroplasty in situ. The mean follow-up of the 79 remaining knees was 7 ± 2 years (5 to 11). The presence of non-progressive radiolucent lines around the augment in 14% of knees was not associated with poorer knee scores, the range of movement, survival of the component or the type of insert which was used (p > 0.05). The survival of the components was 92 ± 0.03% at 11 years (95% CI, 10.3 to 11.2). We recommend the use of modular augmentation devices to treat type-2 defects in revision knee surgery.
The management of chronic osteomyelitis using the Lautenbach method
Authors: Hashmi M. A. , Norman P. , Saleh M. 
Published: March 2004

We describe our medium-term results for the management of chronic osteomyelitis in long bones using the Lautenbach procedure. Seventeen consecutive patients (18 segments) were treated prospectively. Osteomyelitis had been present for a mean of 12.5 years (1 to 31). A discharging sinus was present in all cases. Nine of the associated fractures had failed to unite and a further two needed correction of malunion. The Lautenbach procedure involves debridement, intramedullary reaming and the insertion of double-lumen tubes to establish both a local antibiotic delivery system and cavity analysis for volume and culture. The end-point of treatment is when the irrigate produces three consecutive clear cultures with improvement in the blood indices and obliteration of the cavity volume. The mean length of treatment was 27 days (14 to 48). One patient required a second procedure and another local debridement for recurrence of the infection. Two patients had Papineau grafting because of cortical defects. All the patients have subsequently remained free from infection. After treatment 11 had internal or external fixation for treatment of non- or malunion or a joint replacement, including two successful limb-lengthening procedures. Two further patients, while cured of infection, underwent amputation for other reasons. The mean length of follow-up was 75 months. This procedure allows precise control over the osteomyelitis until objective assessment suggests that infection has been cleared and the cavity obliterated. We recommend this procedure for long-standing complex cases in which basic techniques using debridement and antibiotics have failed.
Hybrid alumina total hip arthroplasty using a press-fit metal-backed socket in patients younger than 55 years
Authors: Bizot P. , Hannouche D. , Nizard R. , Witvoet J. , Sedel L. 
Published: March 2004

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.
Reoperation after autologous chondrocyte implantation
Authors: Henderson I. , Tuy B. , Oakes B. 
Published: March 2004

We have reviewed 22 patients from a total of 135 treated by autologous chondrocyte implantation (ACI) who had undergone further surgery for pain in the knee and mechanical symptoms after a mean of 10.5 months. There were 31 grafted lesions. At operation the findings included lifting (24/31) and detachment (3/31) of periosteal patches for which arthroscopic shaving was performed. Chondroplasty was undertaken on two new lesions, another required an ACI and a further patient required trimming of a meniscus. The mechanical symptoms resolved within two weeks. At the last review, two to 14 months from reoperation; 68% had improved, and 86% had normal or nearly normal IKDC scores. Of the 31 lesions, 30 (97%) had normal or nearly normal visual repair scores. Biopsy showed good integration with subchondral bone and the marginal interface in all specimens, most of which showed hyaline or hyaline-like cartilage (70%). Troublesome mechanical symptoms required surgery in 13% of ACI-treated patients and were attributed to periosteal extrusion. Simple arthroscopic debridement was curative.
Preservation of the bone mineral density of the femur after surface replacement of the hip
Authors: Kishida Y. , Sugano N. , Nishii T. , Miki H. , Yamaguchi K. , Yoshikawa H. 
Published: March 2004

We investigated the effect of the Birmingham hip resurfacing (BHR) arthroplasty on the bone mineral density (BMD) of the femur. A comparative study was carried out on 26 hips in 25 patients. Group A consisted of 13 patients (13 hips) who had undergone resurfacing hip arthroplasty with the BHR system and group B of 12 patients (13 hips) who had had cementless total hip arthroplasty with a proximal circumferential plasma-spray titanium-coated anatomic Ti6A14V stem. Patients were matched for gender, state of disease and age at the time of surgery. The periprosthetic BMD of the femur was measured using dual-energy x-ray absorptiomentry of the Gruen zones at two years in patients in groups A and B. The median values of the BMD in zones 1 and 7 were 99% and 111%, respectively. The post-operative loss of the BMD in the proximal femur was significantly greater in group B than in group A. These findings show that the BHR system preserves the bone stock of the proximal femur after surgery.
Union of defects in the pars interarticularis of the lumbar spine in children and adolescents
Authors: Fujii K. , Katoh S. , Sairyo K. , Ikata T. , Yasui N. 
Published: March 2004

Lumbar spondylolysis can heal with conservative treatment, but few attempts have been made to identify factors which may affect union of the defects in the pars. We have evaluated, retrospectively, the effects of prognostic variables on bony union of pars defects in 134 young patients less than 18 years of age with 239 defects of the pars who had been treated conservatively. All patients were evaluated by CT scans when first seen and more than six months later at follow-up. The results showed that the spinal level and the stage of the defects were the predominant factors. The site of the defects in the pars, the presence or development of spondylolisthesis, the condition of the contralateral pars, the degree of lumbar lordosis and the degree of lumbar inclination all significantly affected union.
Giant-cell tumour of bone
Authors: Zhen W. , Yaotian H. , Songjian L. , Ge L. , Qingliang W. 
Published: March 2004

Giant-cell tumour of bone (GCT) is a locally benign aggressive tumour. The use of adjuvant agents, such as phenol or liquid nitrogen has been recommended to destroy the remaining tumour cells after curettage, and filling of the defect with methylmethacrylate cement has been advocated. Between 1957 and 1992 we treated 92 patients with a GCT with 50% aqueous zinc chloride solution and bone grafting. Their mean age at the time of surgery was 31 years (15 to 59) and the mean follow-up was 11 years (5 to 31). Twelve (13%) had a local recurrence and one had a wound infection. Two developed degenerative changes around the knee. Eighty-six (93%) achieved good or excellent function. Three had moderate function, and three needed amputation. Our findings indicate that treatment with an aqueous solution of zinc chloride and reconstructive bone grafting after curettage gives good results.