bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estrogen replacement, aging, and cell-mediated immunity after injury
Authors: Kovacs Elizabeth J , Plackett Timothy P , Witte Pamela L 
Published: February 2004

AbstractWe recently demonstrated that aged mice are less likely to survive following traumatic injury and are more immunosuppressed than young mice who sustain comparable injuries. Immunosuppression in severely injured patients and in rodent models of burn injury is associated with a marked elevation in proinflammatory cytokines, including interleukin-6 (IL-6). We reported that after sustaining a moderate-size scald injury, aged mice have higher circulating levels of IL-6 than young, injured mice. As proestrus levels of estrogen have been reported to boost immune responses and attenuate IL-6 production, in the present study, we went on to determine if estrogen replacement in aged female mice restored cellular immunity and proinflammatory cytokine production. After injury, in placebo-treated, aged animals, there was a &gt;75% suppression in the delayed-type hypersensitivity response relative to placebo-treated, sham-injured, aged mice (P&lt;0.05). In contrast, estrogen supplementation before injury yielded a partial recovery in this response, such that the mice were suppressed by only 40% relative to sham-injured, aged mice (P&lt;0.05). There was a fourfold increase in the circulating level of IL-6 in burn-injured, aged mice who received placebo hormone replacement relative to sham-injured mice given placebo (P&lt;0.05). This level of cytokine was lowered by nearly 50% in aged, estrogen-treated mice. Most remarkably, estrogen replacement improved survival from 42% (in the absence of estrogen) to 70% in aged, burn-injured mice. Further investigation will be needed to determine if age- and gender-specific therapies are needed for the treatment of all trauma patients.
New Tumor-Node-Metastasis Staging Strategy for Node-Positive (stage III) Rectal Cancer: An Analysis
Authors: Greene Frederick L. , Stewart Andrew K. , Norton H. James 
Published: February 2004

Purpose The tumor-node-metastasis system for staging rectal cancer is based on invasion, number of involved nodes, and metastasis. Nodes are classified as N1 or N2 according to the number involved with metastases. Nodal positivity defines stage III regardless of depth of invasion or number of positive nodes. Our purpose was to analyze overall survival when node-positive patients were stratified into three new subsets. Methods We analyzed data entered into the National Cancer Data Base for 5,987 stage III patients with rectal cancer between 1991 and 1993. Survival was calculated using three new subgroups (IIIA: T1/2, N1; IIIB: T3/4, N1; IIIC: any T, N2). Survival following surgery and adjuvant therapy was assessed. The observed survival rates were calculated and compared using the log-rank method. The Cox regression model assessed subgroup differences. Results Five-year observed survival rates for stage III subcategories were 55.1% in IIIA; 35.3% in IIIB; and 24.5% in IIIC. Stratifying for treatment outcome, stage IIIA patients having surgery alone (n = 278) had poorer observed 5-year survival (39%) than patients treated with surgery and adjuvant chemotherapy or radiation therapy (chemo/XRT; n = 765; 60%). Similar outcomes occurred in IIIB (surgery-alone [n = 726; 21.7%] and chemo/XRT [n = 2,130; 40.9%] groups) and in IIIC (surgery-alone [n = 467; 12.2%] and chemo/XRT [n = 1,621; 28.9%] groups). Differences were significant (P < .0001) in all stages. Conclusion The traditional stage III designation of rectal cancer fails to account for invasion (T1-4) and number of involved nodes (N1, N2). The stratification of stage III patients into three subsets should be used in future analyses of rectal cancer. The effect of postoperative adjuvant therapy was beneficial in all subsets.
Effects of HMPA on the Structure and Reactivity of the Lithium Enolate of Cyclopentanone in THF: The Dimer is Responsible for Alkylation and Proton Exchange Reactions
Authors: Suzuki Masaaki , Koyama Hiroko , Noyori Ryoji 
Published: February 2004

Abstract
The structure and reactivity of the lithium enolate of cyclopentanone are strongly influenced by coexisting HMPA molecules. Detailed low-temperature 7Li, 31P, and 13C NMR studies of the 0.04–0.2 M THF solutions indicate that excess quantities of HMPA act primarily to form a bis-HMPA coordinated dimer. Tetrameric, trimeric, and monomeric enolates were not detected by HMPA titration. The convergency on the dimeric aggregate has been monitored by the successive displacement of THF with HMPA molecules. Even at a high concentration of HMPA, the formation of monomeric enolate was not observed. Kinetic experiments, combined with the structural information, showed that alkylation of the enolate by methyl iodide proceeds via the dimer with the assistance of HMPA. Proton exchange between the enolate and 2-methylcyclopentanone also occurs via the dimer, but without the participation of additional HMPA. These findings explain the role of HMPA in the selective monoalkylation of lithium enolate.
Effects of a High Magnetic Field on the Growth of 3-Dimensional Silver Dendrites
Authors: Katsuki Akio , Uechi Ichiro , Tanimoto Yoshifumi 
Published: February 2004

Abstract
A liquid/solid redox reaction between silver ions and copper metal was investigated under a vertical and inhomogeneous high magnetic field (maximum field strength: 15 T). The 3-dimensional silver dendrites produced via the reaction were drastically affected by the magnetic field. Black and round dendrites were obtained in the magnetic field, whereas metallic silver crystals were grown under the gray dendrites with no field. The yields of the silver dendrite and the copper ion increased significantly in presence of the magnetic field. The results are interpreted in terms of the magnetic convection of the solution, which is induced by the magnetic force on the paramagnetic copper ions generated in the reaction as well as by the Lorentz force on the ions.
Motif Analysis of Amino-Acid Sequences by a Quantification Method: Application to Phosphorylation Signals of Protein Kinase C and cAMP-Dependent Protein Kinase
Authors: Iida Yôichi 
Published: February 2004

Abstract
Prediction of protein function using amino-acid sequence motifs is based on the observation that the functionally important region is strongly conserved in short segments of amino-acid sequences. Although the consensus sequence has been used to describe such a functional signal, the actual sequence differs from it to a greater or lesser degree, and the consensus sequence only describes the signal qualitatively. In the present report, we study phosphorylation signals of protein kinase C (PKC) and cAMP-dependent protein kinase (PKA). PKC phosphorylates solely Ser or Thr residues. The consensus sequence is given by (R/K1–3,X2–0)-S/T-(X2–0,R/K1–3), where X denotes no particular amino acid. PKA also phosphorylates Ser or Thr, but its consensus sequence is described by R-R/K-X-S/T. We analyzed such signals by a quantification method, and estimated the strength of the signal quantitatively. This approach was applied to several proteins and peptide analogues, and the replacement effect of amino acids upon catalytic activities of phosphorylation was explained in terms of the strength of the signal (sample score of peptide sequence).
[{RhCl(CO)2}2]-Derived MCM-41-Tethered Rhodium Complex Catalysts via Phosphine, Amine and Thiol Ligands for Cyclohexene Hydroformylation
Authors: Huang Lin , Kawi Sibudjing 
Published: February 2004

Abstract
Functionalized silicate MCM-41-tethered rhodium complexes derived from [{RhCl(CO)2}2] have been studied by infrared spectroscopy (IR), X-ray diffraction (XRD) and N2 adsorption–desorption. [{RhCl(CO)2}2] reacts with aminated MCM-41 to result in a splitting of the chloride bridge. The same result is presumed with phosphinated MCM-41. Thiolated MCM-41 is presumed to displace the chloride in the bridge with thiol ligands. The tethering of rhodium complexes to MCM-41 leads to reduced pore sizes, pore volumes and BET surface areas without altering the structural ordering of MCM-41. The MCM-41-tethered catalysts show distinct activities and resistance to rhodium leaching in cyclohexene hydroformylation under equimolar CO and H2 at 28 bar and 100 °C, depending on the nature of complexation of the supported donor ligands with the rhodium centre. The aminated MCM-41-tethered catalyst displays good activity, selectivity and recycling for the formation of cyclohexane carboxaldehyde. The mesoporous structure of MCM-41 remains stable during the reaction.
Synthesis of Novel Amidinato(amidine) Complexes of Molybdenum via Bis(amidine) Complexes
Authors: Yamaguchi Yoshitaka , Ogata Kenichi , Kobayashi Kimiko , Ito Takashi 
Published: February 2004

Abstract
The molybdenum complex [Mo(η3-allyl)Cl(CO)2(NCMe)2] (1) reacted with two equivalents of amidines, ArN=C(R)NHAr (R = H, CH3; Ar = C6H5, p-CH3–C6H4) (2), to give corresponding bis(amidine) complexes, [Mo(η3-allyl)Cl(CO)2(amidine)2] (3). Upon a treatment of bis(amidine)molybdenum complexes (3) with a base, such as n-butyllithium, complexes (4) bearing both amidinato and amidine ligands were formed and isolated as a yellow solid. The amidine ligand in complexes 4 was easily substituted by PEt3 to give amidinato(phosphine) complexes of molybdenum (5) as a red solid. These complexes were characterized spectroscopically as well as by X-ray analyses.
Imidazole Catalyzed Oxidations with Organic Peroxides: A Kinetic Study
Authors: Shawakfeh Khaled Q , Al-Ajlouni Ahmad M 
Published: February 2004

Abstract
Imidazole and 1-methylimidazole catalyze the oxidation of indigo dyes with m-chloroperoxybenzoic acid (MCPBA) in organic and mixed aqueous solutions. The kinetics of these reactions were studied in CH3OH/CH3CN and CH3OH/H2O solvent systems. The reaction rates decreased with the solvent polarity. The catalytically active species is proposed as an MCPBA–Im adduct which is in equilibrium with MCPBA and the imidazole. The equilibrium constant (K ∼ 70) for the formation of the MCPBA–Im adduct was determined in CH3OH/H2O (8:2). The catalyzed rates are at least three-orders of magnitude faster than the uncatalyzed rates. The electron-rich, 1-methylimidazole, increases the rate of oxidation of indigo blue via MCPBA more than imidazole itself. A mechanism similar to the Michaelis–Menten type was proposed for these reactions. The initial products from oxidation of indigo dyes by MCPBA are the epoxides, which undergo a slow ring-opening in the presence of water to form 1,2-diol products.
Stabilization of Carboxylate Anion with a NH···O Hydrogen Bond: Facilitation of the Deprotonation of Carboxylic Acid by the Neighboring Amide NH Groups
Authors: Onoda Akira , Yamada Yusuke , Takeda Jiro , Nakayama Yoshiki , Okamura Taka-aki , Doi Mototsugu , Yamamoto Hitoshi , Ueyama Norikazu 
Published: February 2004

Abstract
The formation of the NH···O hydrogen bonds of carboxylic acids, 2,6-(t-BuCONH)2C6H3COOH (1) and 2-t-BuCONH-6-MeC6H3COOH (2), carboxylate, [NEt4][2,6-(t-BuCONH)2C6H3COO] (3), and a mixed complex, [N(n-Pr)4][H{2,6-(t-BuCONH)2C6H3(COO)}2] (4), were determined by X-ray structure analysis, 1H NMR, and IR spectroscopy, both in the solid state and in solution. The amide NH group forms weak intramolecular hydrogen bond between the NH and O=C group, and no NH···OH hydrogen bond is formed in the carboxylic acid state. Carboxylate anion 3 forms a strong, intramolecular, partially-covalent hydrogen bond between NH···O− (anion). The strength of the NH···O hydrogen bonds is also maintained in a solution having a low dielectric constant. The pKa values for 1 and 2, measured in a micellar solution, indicated that one of the important triggers for deprotonation is a direct interaction toward the oxygen atom of the OH group with the amide NHs.
Study on the Structure Activity Relationships of NPTX-594, a Spider Toxin Belonging to the Type-B Acylpolyamine Structure
Authors: Wakamiya Tateaki , Kinoshita Tomohiko , Hattori Yoshihide , Yamaguchi Yoshihiro , Naoki Hideo , Corzo Gerardo , Nakajima Terumi 
Published: February 2004

Abstract
In order to elucidate the structure activity relationships of the spider toxin termed NPTX-594, eleven toxin analogs were designed and synthesized, and their paralytic activities against cricket were tested. As a result of the present study, it was clarified that the Lys residue binding to the 1-amino group of 4,8-diaza-1,12-dodecanediamine (Dada) in the molecule of NPTX-594 is not an essential requisite for toxicity, and can be replaced with neutral or basic amino acids without any considerable loss of the activity. However, the replacement of the Lys residue with acidic amino acid residues, such as Asp or Glu, resulted in an extreme loss of the biological activity.
The Barbier-Type Alkylation of Aldehydes with Alkyl Halides in the Presence of Metallic Strontium
Authors: Miyoshi Norikazu , Kamiura Koji , Oka Hiromi , Kita Akiko , Kuwata Rika , Ikehara Daitetsu , Wada Makoto 
Published: February 2004

Abstract
In the presence of metallic strontium, the Barbier-type alkylation of aldehydes with alkyl iodides proceeded smoothly at −15 °C under an argon atmosphere to afford the corresponding alkylated alcohols in moderate to good yields. The unusual addition reaction of ethyl benzoate with tert-butyl iodide took place to give the p-tert-butylated alkylated product (the 1,6-adduct of the benzoate) in 55% yield. Using strontium isopropoxide, the Meerwein–Ponndorf–Verley-type reduction of the aldehyde proceeded smoothly under reflux conditions in 2-propanol.
Hydroesterification of Vinylarenes Catalyzed by Palladium Complexes of Dialkylmonoaryl- and Monoalkyldiarylphosphines
Authors: Kawashima Yasutoyo , Okano Kentaro , Nozaki Kyoko , Hiyama Tamejiro 
Published: February 2004

Abstract
Hydroesterification of vinylarenes using a mixture of PdCl2 and monodentate phosphorus ligands as a catalyst was studied. As ligands, menthyldiphenylphosphine (MDPP), neomenthyldiphenylphosphine (NMDPP), and dicyclohexyl(phenyl)phosphine (Cy2PPh) were effective to obtain branched esters with high regioselectivity under the moderate reaction conditions without additives such as acids. Not only electronic effects but also steric effects of the cycloalkyl groups were revealed to be significant in order to achieve high catalytic activity. When (S)-2-dicyclopentylphosphino-2′-methoxy-1,1′-binaphthyl was used for the asymmetric hydroesterification of 2-methoxy-6-vinylnaphthalene, (S)-naproxen methyl ester was obtained with 53% ee.
Correlation between the g Tensors and the Nonplanarity of Porphyrin Rings in Desulfovibrio vulgaris Miyazaki F Cytochrome c3, Studied by Single Crystal EPR
Authors: Saitoh Takashi , Tachibana Yoshihiko , Higuchi Yoshiki , Hori Hiroshi , Akutsu Hideo 
Published: February 2004

Abstract
Single crystals of cytochrome c3 from Desulfovibrio vulgaris Miyazaki F were examined by EPR at cryogenic temperature. The principal values and the eigenvectors are determined. The four sets of EPR signals are directly assigned to the specific four hemes in the three-dimensional structure. The relative energy levels of the three d orbitals (dXY, dXZ, and dYZ) of each heme iron calculated from the obtained principal g values have shown that the energy gap between dXY and dπ is small for a heme with the S4-ruffled distortion (heme 1 and heme 2) while the energy gap is large for a heme with the S4-saddled distortion (heme 4). The determined g tensor orientations indicated that the principal g axes of heme 1, heme 2, heme 3, and heme 4 co-rotate with the imidazole planes of the sixth ligands.
Covalent Linking of Coordination-Organized Slipped Cofacial Porphyrin Dimers
Authors: Ohashi Atsushi , Satake Akiharu , Kobuke Yoshiaki 
Published: February 2004

Abstract
Coordination-organized porphyrin dimers of 5,15-bis[2-(allyloxycarbonyl)ethyl]- and bis[3-(allyloxy)propyl]-20-(1-methyl-2-imidazolyl)porphyrinatozinc were covalently linked by an intramolecular olefin metathesis reaction in excellent yields (93–98%). It was found that the yields of the intramolecular metathesis reaction depended strongly on the molecular length of the substituent at the 5 and 15 positions. Introducing longer 3-(allyloxycarbonyl)propyl and 4-(allyloxycarbonyl)butyl substituents decreased sharply the yields of the covalent linking reaction to 26% and 16%, respectively. The covalently linked dimers maintained their coordination structures even when dissolved in as polar a solvent as pyridine.
Isolation and Stereochemistry of Optically Active Selenoximines
Authors: Shimizu Toshio , Mitsuya Kazuhiko , Hirabayashi Kazunori , Kamigata Nobumasa 
Published: February 2004

Abstract
Asymmetric selenoximines were synthesized and their optical isomers were isolated for the first time by optical resolution using chromatography with a chiral column. The absolute configuration was determined by comparing their specific rotations and their circular dichroism spectra with those of a corresponding sulfur analogue with known absolute configuration. No racemization of the optically active selenoximines occurred under neutral, acidic, and basic conditions, and only decomposition was observed under aqueous acidic and basic conditions.
The Facile Preparation, Crystal Structure, and Chemical and Electrochemical Properties of 9-Anthryl-3-guaiazulenylmethylium Hexafluorophosphate
Authors: Takekuma Shin-ichi , Sasaki Kaori , Nakatsuji Miwa , Sasaki Masato , Minematsu Toshie , Takekuma Hideko 
Published: February 2004

Abstract
Reaction of guaiazulene (1) with anthracene-9-carbaldehyde in methanol in the presence of hexafluorophosphoric acid at 25 °C for 30 min gave the title compound 2 in 88% yield.
Dehydrogenation and Isomerization of Butane over Cr Catalysts Supported on H-SSZ-35 Type Zeolites
Authors: Inaba Megumu , Murata Kazuhisa , Saito Masahiro , Takahara Isao , Mimura Naoki , Hamada Hideaki , Kurata Yohei 
Published: February 2004

Abstract
The dehydrogenation and isomerization of butane to isobutene over Cr catalysts supported on zeolites were investigated. Although a zeolite support, especially with a low Si/Al2 ratio, favors the cracking of butane over its dehydrogenation and isomerization, due to strong solid acidity, the loading of Cr on a zeolite support enhances the dehydrogenation and isomerization of butane. H-SSZ-35 type zeolite, which has a one-dimensional cage-type channel structure, was hydrothermally synthesized using cis,cis,cis-N-methylhexahydrojulolidinium hydroxide as a structure-directing agent (SDA). We found that Cr/H-SSZ-35 (Si/Al2 = 500) showed moderate butane conversion and isobutene selectivity. As a result, the yield of isobutene (conversion of butane × selectivity of isobutene) was the highest among the catalysts used in this study. Its activity at 500 °C remained unchanged for 6 h. Our evidence suggests that butane was dehydrogenated over the zeolite support or Cr2O3 particles, and a proportion of the dehydrogenated products were isomerized to isobutene over the zeolite support.
Preparation and Characterization of LiCl-Occluded LiLSX Zeolite
Authors: Yoshida Satoshi , Harada Atsushi , Kamioka Kunikazu , Nakano Masao 
Published: February 2004

Abstract
LiCl-occluded LiLSX (Li exchanged Low Silica X zeolite with Si/Al = 1.0) was prepared by a heat treatment after evaporating a LiLSX or NaLSX slurry with LiCl, followed by lithium exchange in the case of NaLSX. The amount of occluded LiCl increased with increasing of the temperature. LiCl-occluded LiLSX prepared from NaLSX had a higher crystallinity than that prepared from LiLSX. The difference in crystallinity is explained as being related to the difference in the distortion of the skeleton structure of the zeolites. Chloride anions in high-crystallinity LiCl-occluded LiLSX were found to be located in sodalite cages by a Fourier synthesis of the powder X-ray diffraction pattern. The location of lithium cations was investigated based on the adsorption properties of nitrogen at room temperature and existing data on salt-occluded zeolites. Lithium cations in LiCl-occluded LiLSX are thought to simultaneously occupy the adjacent sites I and I′.
Electroreduction of Oxygen at a Pt/C-Modified Electrode with a Cobaltporphyrin Complex
Authors: Shentu Baoqing , Oyaizu Kenichi , Nishide Hiroyuki 
Published: February 2004

Abstract
Cobalt complexes that reversibly bind and release O2 functioned as O2 carriers, or O2-enriching media, at the surface of a cathode to enhance the current for the reduction of O2. The effect of the cobalt complex to accumulate O2 was evidenced by the higher open-circuit potential, which reflected the equilibrated concentration of O2 at the electrode surface. The combination of the cobalt complex and the conventional Pt/C catalyst resulted in a significant increase in the steady-state current for the four-electron reduction of O2, particularly at small overpotentials where typical fuel cells operate, based on the facilitated transport of O2 from the atmosphere to the catalyst at the electrode surface.
Preparation of Hydrogenated Surfactant/SC CO2 Micelles and Their Micropolarity Determination
Authors: Shervani Zameer , Liu Juncheng , Ikushima Yutaka 
Published: February 2004

Abstract
The influence of CO2-philicity and -phobicity of hydrogenated surfactants on preparation of reverse micelles in SC CO2 have been investigated for the first time. To this end, we used polyethylene glycol mono n-alkyl ether surfactants of different polar head groups and alkyl tails. Micelles prepared were characterized by dissolving 1-ethyl-4-methoxycarbonyl pyridinium iodide probe and recording its charge-transfer band in UV absorption region. From the transition energy of charge transfer band the polarity of the aqueous core of micelles was determined in terms of solvent polarity scale ET (30) values.
Bleeding and Thrombosis in High-Risk Renal Transplantation Candidates Using Heparin
Authors: Mathis A Scott , Davé Nisha , Shah Nita K , Friedman Gary S 
Published: February 2004

BACKGROUND Heparin can reduce the risk of renal artery/vein thrombosis in renal transplant patients with hypercoagulable states (HCS), but is associated with a high bleeding risk. Little is known about risk factors for this bleeding risk or the optimal anticoagulation target. OBJECTIVE To determine factors associated with this bleeding risk and determine the optimal partial thromboplastin time (PTT) ratio. METHODS We retrospectively reviewed medical records of consecutive adult renal transplant recipients administered heparin for perioperative renal thrombosis prevention (1998–2002). RESULTS Twenty-eight (3.86%) of 725 consecutive renal transplant recipients received heparin to prevent renal thrombosis. Eighteen patients (64.3%) had clinically important bleeding (14 major bleeding). Patients with and without bleeding were similar in baseline demographic characteristics and overall mean PTT. Bleeding occurred at a mean PTT ratio of 2.5 ± 1, higher than the overall mean in bleeders and nonbleeders (p = 0.001). Among postoperative characteristics, higher maximum PTT (p = 0.052) and prolonged surgical antibiotic prophylaxis (p = 0.053), particularly with cefotetan (p = 0.091), trended toward a significant association with bleeding. Two renal thrombotic episodes occurred, both at PTT ratios <1.5. A PTT ratio of 1.5–1.9 resulted in no thrombosis and ≤4.2% bleeding. CONCLUSIONS The benefits and risks of therapeutic heparin anticoagulation in renal transplant patients with HCSs were confirmed. Higher PTTs and cefotetan antibiotic surgical prophylaxis could contribute to bleeding. The optimal PTT ratio appeared to be 1.5–1.9 to prevent thrombosis and limit bleeding risk.