bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet-derived LIGHT induces inflammatory responses in endothelial cells and monocytes
Authors: Otterdal Kari , Smith Camilla , Øie Erik , Pedersen Turid M. , Yndestad Arne , Stang Espen , Endresen Knut , Solum Nils O. , Aukrust Pål , Damås Jan K.
Published: April 2006

Traditionally, platelets are known to play an important role in hemostasis, thrombosis, and wound healing, but increasing evidence suggests that activated platelets also may promote inflammation. Platelet-induced modulation of inflammation seems to involve platelet expression of ligands in the tumor necrosis factor (TNF) superfamily such as CD40 ligand and Fas ligand. The present study demonstrates that LIGHT, another member of the TNF superfamily, is associated with platelets and is released as a soluble ligand on platelet activation. The release of LIGHT involves GP IIb/IIIa-dependent mechanisms and action of metal-dependent proteases as well as intracellular processes such as actin polymerization. We also report that platelet-derived LIGHT is biologically active and can induce an inflammatory response in monocytes and particularly within endothelial cells measured as up-regulation of adhesion molecules and release of chemokines. Moreover, we demonstrate that thrombus material, obtained at the site of plaque rupture in patients with acute myocardial infarction, contains platelet-associated LIGHT, suggesting that LIGHT-mediated inflammation also is operating in vivo within an inflamed and thrombotic vessel wall. The data may suggest a pathogenic role for platelet-derived LIGHT in atherogenesis and plaque destabilization as well as in other inflammatory disorders involving leukocyte infiltration into the vessel wall.
The apoptotic-cell receptor CR3, but not αvβ5, is a regulator of human dendritic-cell immunostimulatory function
Authors: Škoberne Mojca , Somersan Selin , Almodovar Wanda , Truong Tuan , Petrova Kseniya , Henson Peter M. , Bhardwaj Nina
Published: April 2006

Dendritic cells (DCs) that capture apoptotic cells (ACs) in the steady state mediate peripheral tolerance to self-antigens. ACs are recognized by an array of receptors on DCs, the redundancy of which is not completely defined. We made use of an AC surrogate system to address the individual roles of the αvβ5 and complement receptors (CRs) in the phagocytosis and induction of immunity. CR3 and CR4, while substantially less efficient than αvβ5 in internalizing ACs, initiate signals that render DCs tolerogenic. Responding T cells show impaired proliferation and IFNγ production and subsequently die by apoptosis. While tolerogenic DCs are not induced via αvβ5, coligation of CR3 and αvβ5 maintains the DC's tolerogenic profile. This immunomodulatory role, however, is countered by a significant inflammatory stimulus such as bacterial infection. Overall, our data suggest that under steady-state conditions, signaling via CRs predominates to render DCs tolerogenic.
Unique effects of Stat3 on the early phase of hematopoietic stem cell regeneration
Authors: Chung Yang-Jo , Park Bo-Bae , Kang Young-Ju , Kim Tae-min , Eaves Connie J. , Oh Il-Hoan
Published: April 2006

Self-renewal of hematopoietic stem cells (HSCs) is key to their reconstituting ability, but the signaling pathways that regulate this process remain poorly understood. Here we show that transduction of adult mouse bone marrow cells with a constitutively activated form of Stat3 (Stat3-C) increased their regenerative activity in lethally irradiated recipients. Conversely, transduction of these cells with a dominant-negative form of Stat3 suppressed their regenerative activity. Serial transplantation and clonal tracking of the HSC progeny regenerated in vivo from STAT3-C–transduced HSCs demonstrated that the major effect of forced expression of STAT3-C was to enhance HSC self-renewal during the initial phase of hematopoietic recovery. This acquired potential for enhanced self-renewal divisions then became latent, but was reactivated when the cells were transferred to new irradiated recipients. Increased levels of activated STAT3 were also found to be associated with greater preservation of primitive hematopoietic cells in short-term cultures. These results indicate a novel biphasic regulation of HSC self-renewal in vivo in which activated STAT3 promotes HSC self-renewal under stimulated, but not homeostatic, conditions. STAT3 may thus be an important regulator of hematopoietic regeneration and a novel target for HSC engineering.
Physicians' Preparedness for Bioterrorism and Other Public Health Priorities
Authors: Alexander G. Caleb , Larkin G. Luke , Wynia Matthew K.
Published: April 2006

Objectives

Potential bioterrorism challenges policy makers to balance competing public health priorities. Earlier surveys showed low physician bioterrorism preparedness but did not assess physicians' general public health preparedness, compare the preparedness of emergency and primary care physicians, or assess temporal trends.

Methods

This was a national, cross‐sectional, random‐sample survey conducted in 2003.

Results

Overall, 744 of 1,200 eligible physicians responded (response rate, 62%). Of these, 58% of emergency physician respondents and 48% of primary care physician respondents reported having learned a lot about responding to bioterror since September 11, 2001 (p < 0.01). However, only 43% of emergency physicians and 21% of primary care physicians agreed they are generally “well prepared to play a role in responding to a bioterror attack” (p < 0.001). Beliefs about balancing public health priorities were similar among emergency and primary care respondents. Seventy‐eight percent of respondents believed that local health care systems need to be prepared for bioterrorism, and 92% believed that local health care systems need to be prepared for natural epidemics. By contrast, only 23% and 46% of respondents reported that their local health care systems are well prepared for bioterrorism and natural epidemics, respectively. Meanwhile, 77% agreed that “influenza is a greater threat to public health than bioterrorism,” and 21% reported that bioterrorism preparedness efforts are diverting resources from more important public health problems.

Conclusions

In 2003, most emergency and primary care physicians reported that they and their local health care systems were not yet well prepared to respond to a bioterror attack, and many believed that more resources should go toward preparing for natural epidemics. These findings highlight the importance of expanding bioterrorism preparedness efforts to improve the public health system more broadly.
Single Question about Drunkenness to Detect College Students at Risk for Injury
Authors: O'Brien Mary Claire , McCoy Thomas P. , Champion Heather , Mitra Ananda , Robbins Adrienne , Teuschlser Hoa , Wolfson Mark , DuRant Robert H.
Published: April 2006

Objectives:
To examine the frequency of injuries reported by college students who replied affirmatively to the question, “In a typical week, how many days do you get drunk?”

Methods:
In Fall 2003, a Web‐based survey was administered to a stratified random sample of 3,909 college students from ten North Carolina (NC) universities. Students answered questions regarding alcohol use and its consequences. Data were analyzed using multiple logistic regression, controlling for within‐school clustering of drinking behaviors and adjusting for other significant covariates. Adjusted odds ratios (AORs) and 95% confidence intervals (CI) were calculated for significant predictors (p < 0.05).

Results:
Two thousand four hundred eighty‐eight students reported that they are current drinkers; 1,353 (54.4%) reported getting drunk at least once in a typical week. Compared with students who did not report getting drunk at least once a week, these students had higher odds of being hurt or injured at least once as a result of their own drinking (AOR = 4.97; 95% CI = 3.47 to 7.09), experiencing a fall from a height that required medical treatment (AOR = 2.16; 95% CI = 1.36 to 3.43), and being taken advantage of sexually as a result of another's drinking (AOR = 2.59; 95% CI = 1.72 to 3.89). Students who reported getting drunk at least one day in a typical week also were more likely to cause an injury requiring medical treatment to someone else. They had higher odds of causing injury in an automobile crash (AOR = 1.84; 95% CI = 1.01 to 3.40), of causing a burn that required medical treatment (AOR = 2.85; 95% CI = 1.51 to 5.39), and of causing a fall from a height that required medical treatment (AOR = 2.02; 95% CI = 1.01 to 4.04). Getting drunk was a better indicator of “self‐experienced injury” and of “injury caused to someone else” than was binge drinking, for all outcomes (p < 0.05).

Conclusions:
The single question, “In a typical week, how many days do you get drunk?” identifies college students who are at higher than normal risk of injury as a result of their own drinking and the drinking of others. Future research should assess this question's effectiveness as a screening tool in campus health centers and in emergency departments.
The Effects of a Physician Slowdown on Emergency Department Volume and Treatment
Authors: Walsh Brian , Eskin Barnet , Allegra John , Rothman Jonathan , Junker Elizabeth
Published: April 2006

Objectives

In February 2003, many physicians in New Jersey participated in a work slowdown to publicize large increases in malpractice premiums and generate support for legislative reform. It was anticipated that the community physician slowdown (hereafter referred to as “slowdown”) would increase emergency department (ED) visits. The authors' goal was to help others prepare for anticipated increases in ED volumes by describing the preparatory staffing changes made and quantifying increases in ED volume.

Methods

This was a retrospective cohort study performed at a New Jersey suburban teaching hospital with 70,000 annual visits. Consecutive patients seen by emergency physicians were enrolled. The authors extracted patient visit data from the computerized tracking system and analyzed hours worked by personnel, patient volumes, admission rates, and patient throughput times. Variables from each day of the slowdown with baseline values for the same day of the week for the four weeks before and after the slowdown were compared. A Bonferroni correction was used, with p < 0.01 considered statistically significant.

Results

Total patient volume increased 79% from baseline (95% confidence interval [CI] = 20% to 137%). Pediatric volume increased 223% (95% CI = 171% to 274%). Overall admission rate decreased 29% compared with baseline (95% CI = 8% to 51%). Patient throughput times did not change significantly. Similar results for these variables were found for the second through fourth days of the slowdown.

Conclusions

Emergency department visits, especially pediatric visits, increased markedly during the community physician slowdown. Anticipatory increases in staffing effectively prevented increased throughput times.
Aging and the Use of Context in Ambiguity Resolution: Complex Changes From Simple Slowing
Authors: Dagerman Karen Stevens , MacDonald Maryellen C. , Harm Michael W.
Published: April 2006

Older and younger adults' abilities to use context information rapidly during ambiguity resolution were investigated. In Experiments 1 and 2, younger and older adults heard ambiguous words (e.g., fires) in sentences where the preceding context supported either the less frequent or more frequent meaning of the word. Both age groups showed good context use in offline tasks, but only young adults demonstrated rapid use of context in cross‐modal naming. A 3rd experiment demonstrated that younger and older adults had similar knowledge about the contexts used in Experiments 1 and 2. The experiment results were simulated in 2 computational models in which different patterns of context use were shown to emerge from varying a single speed parameter. These results suggest that age‐related changes in processing efficiency can modulate context use during language comprehension.
Modeling the Development of Children's Use of Optional Infinitives in Dutch and English Using MOSAIC
Authors: Freudenthal Daniel , Pine Julian M. , Gobet Fernand
Published: April 2006

In this study we use a computational model of language learning called model of syntax acquisition in children (MOSAIC) to investigate the extent to which the optional infinitive (OI) phenomenon in Dutch and English can be explained in terms of a resource‐limited distributional analysis of Dutch and English child‐directed speech. The results show that the same version of MOSAIC is able to simulate changes in the pattern of finiteness marking in 2 children learning Dutch and 2 children learning English as the average length of their utterances increases. These results suggest that it is possible to explain the key features of the OI phenomenon in both Dutch and English in terms of the interaction between an utterance‐final bias in learning and the distributional characteristics of child‐directed speech in the 2 languages. They also show how computational modeling techniques can be used to investigate the extent to which cross‐linguistic similarities in the developmental data can be explained in terms of common processing constraints as opposed to innate knowledge of universal grammar.
Diversity and Unity of Modularity
Authors: Seok Bongrae
Published: April 2006

Since the publication of Fodor's (1983) The Modularity of Mind, there have been quite a few discussions of cognitive modularity among cognitive scientists. Generally, in those discussions, modularity means a property of specialized cognitive processes or a domain‐specific body of information. In actuality, scholars understand modularity in many different ways. Different characterizations of modularity and modules were proposed and discussed, but they created misunderstanding and confusion. In this article, I classified and analyzed different approaches to modularity and argued for the unity of modularity. Modularity is a multidimensional property consisting of features from several dimensions specifying different aspects of cognition. Among those, there are core features of modularity, and these core features form a cross‐dimensional unity. Despite the diverse and liberal characterizations, modularity contributes to cognitive science because of the unity of the core features.
The Isolation, Primacy, and Recency Effects Predicted by an Adaptive LTD/LTP Threshold in Postsynaptic Cells
Authors: Sikström Sverker
Published: April 2006

An item that stands out (is isolated) from its context is better remembered than an item consistent with the context. This isolation effect cannot be accounted for by increased attention, because it occurs when the isolated item is presented as the first item, or by impoverished memory of nonisolated items, because the isolated item is better remembered than a control list consisting of equally different items. The isolation effect is seldom experimentally or theoretically related to the primacy or the recency effects—that is, the improved performance on the first few and last items, respectively, on the serial position curve. The primacy effect cannot easily be accounted for by rehearsal in short‐term memory because it occurs when rehearsal is eliminated. This article suggests that the primacy, the recency, and the isolation effects can be accounted for by experience‐dependent synaptic plasticity in neural cells. Neurological empirical data suggest that the threshold that determines whether cells will show long‐term potentiation (LTP) or long‐term depression (LTD) varies as a function of recent postsynaptic activity and that synaptic plasticity is bounded. By implementing an adaptive LTP‐LTD threshold in an artificial neural network, the various aspects of the isolation, the primacy, and the recency effects are accounted for, whereas none of these phenomena are accounted for if the threshold is constant. This theory suggests a possible link between the cognitive and the neurological levels.
Culture and Change Blindness
Authors: Masuda Takahiko , Nisbett Richard E.
Published: April 2006

Research on perception and cognition suggests that whereas East Asians view the world holistically, attending to the entire field and relations among objects, Westerners view the world analytically, focusing on the attributes of salient objects. These propositions were examined in the change‐blindness paradigm. Research in that paradigm finds American participants to be more sensitive to changes in focal objects than to changes in the periphery or context. We anticipated that this would be less true for East Asians and that they would be more sensitive to context changes than would Americans. We presented participants with still photos and with animated vignettes having changes in focal object information and contextual information. Compared to Americans, East Asians were more sensitive to contextual changes than to focal object changes. These results suggest that there can be cultural variation in what may seem to be basic perceptual processes.
Cart Overexpression Is the Only Identifiable Cause of High Bone Mass in Melanocortin 4 Receptor Deficiency
Authors: Ahn Jong Deok , Dubern Beatrice , Lubrano-Berthelier Cecile , Clement Karine , Karsenty Gerard
Published: April 2006

The neural regulation of bone remodeling has proven to be increasingly complex at the molecular level because it involves both positive and negative mediators of bone formation and resorption. One of the mediators expressed in hypothalamic neurons that leptin uses to inhibit osteoclast differentiation and thereby bone resorption is cocaine- and amphetamine-regulated transcript (CART). CART expression in the hypothalamus is increased in mice lacking melanocortin 4 receptor (Mc4r−/− mice). Moreover, we show here that humans or mice lacking only one allele of Mc4r display a decrease in bone resorption parameters, high bone mass, and an increase in CART serum levels and/or hypothalamic expression. To demonstrate that the Cart overexpression is the only identifiable cause for the high bone mass observed upon Mc4r inactivation, we removed one allele of Cart from mice either heterozygous or homozygous for Mc4r inactivation. This manipulation sufficed to either significantly improve or normalize bone resorption parameters, without improving the energy metabolism disturbance that characterizes Mc4r-deficient mice. These results identify CART signaling as the main if not only molecular pathway accounting for the decrease in bone resorption leading to high bone mass in mice and humans deficient in Mc4r. As importantly, they also indicate that CART regulates bone resorption independently of the role it may exert in energy metabolism, suggesting that the neural control of appetite and bone remodeling are independent of each other.
The LIM-Homeodomain Proteins Isl-1 and Lhx3 Act with Steroidogenic Factor 1 to Enhance Gonadotrope-Specific Activity of the Gonadotropin-Releasing Hormone Receptor Gene Promoter
Authors: Granger Anne , Bleux Christian , Kottler Marie-Laure , Rhodes Simon J. , Counis Raymond , Laverrière Jean-Noël
Published: April 2006

The GnRH receptor (GnRH-R) plays a central role in mammalian reproductive function throughout adulthood. It also appears as an early marker gene of the presumptive gonadotrope lineage in developing pituitary. Here, using transient transfections combined with DNA/protein interaction assays, we have delineated cis-acting elements within the rat GnRH-R gene promoter that represent targets for the LIM-homeodomain (LIM-HD) proteins, Isl-1 and Lhx3. These factors, critical in early pituitary development, are thus also crucial for gonadotrope-specific expression of the GnRH-R gene. In heterologous cells, the expression of Isl-1 and Lhx3, together with steroidogenic factor 1 (SF-1), culminates in the activation of both the rat as well as human GnRH-R promoter, suggesting that this combination is evolutionarily conserved among mammals. The specificity of these LIM-HD factors is attested by the inefficiency of related proteins, including Lhx5 and Lhx9, to activate the GnRH-R gene promoter, as well as by the repressive capacity of a dominant-negative derivative of Lhx3. Accordingly, targeted deletion of the LIM response element decreases promoter activity. In addition, experiments with Gal4-SF-1 fusion proteins suggest that LIM-HD protein activity in gonadotrope cells is dependent upon SF-1 binding. Finally, using a transgenic model that allows monitoring of in vivo promoter activity, we show that the overlapping expression of Isl-1 and Lhx3 in the developing pituitary correlates with promoter activity. Collectively, these data suggest the occurrence of a specific LIM-HD pituitary code and designate the GnRH-R gene as the first identified transcriptional target of Isl-1 in the anterior pituitary.
Down-Regulation of the Tumor Suppressor Gene Retinoic Acid Receptor β2 through the Phosphoinositide 3-Kinase/Akt Signaling Pathway
Authors: Lefebvre Bruno , Brand Céline , Flajollet Sébastien , Lefebvre Philippe
Published: April 2006

The retinoic acid receptor β2 (RARβ2) is a potent, retinoid-inducible tumor suppressor gene, which is a critical molecular relay for retinoid actions in cells. Its down-regulation, or loss of expression, leads to resistance of cancer cells to retinoid treatment. Up to now, no primary mechanism underlying the repression of the RARβ2 gene expression, hence affecting cellular retinoid sensitivity, has been identified. Here, we demonstrate that the phosphoinositide 3-kinase/Akt signaling pathway affects cellular retinoid sensitivity, by regulating corepressor recruitment to the RARβ2 promoter. Through direct phosphorylation of the corepressor silencing mediator for retinoic and thyroid hormone receptors (SMRT), Akt stabilized RAR/SMRT interaction, leading to an increased tethering of SMRT to the RARβ2 promoter, decreased histone acetylation, down-regulation of the RARβ2 expression, and impaired cellular differentiation in response to retinoid. The phosphoinositide 3-kinase/Akt signaling pathway, an important modulator of cellular survival, has thus a direct impact on cellular retinoid sensitivity, and its deregulation may be the triggering event in retinoid resistance of cancer cells.
RAI-III and VI, Conformational Isomers of Antitumor Cyclic Hexapeptides, RA-III and VI from Rubia cordifolia
Authors: Itokawa Hideji , Morita Hiroshi , Takeya Koichi , Tomioka Nobuo , Itai Akiko
Published: April 2006

RAI-III and VI, conformational isomers of antitumor bicyclic hexapeptides, RA-III and VI, respectively, were isolated from Rubia cordifolia. By the conformational analysis of them using spectroscopic and computational chemical methods, they were shown to have γ-turn structures at residues 2,3, and 4, which were stabilized by a hydrogen bond between Ser-2-OH and D-Ala-1-CO.
Peroxyoxalate Chemiluminescent Assay of Ascorbic Acid Based on Autoxidation with Oxygen in Reversed Micelle
Authors: Kamidate Tamio , Katoh Masaki , Segawa Tadashi , Watanabe Hiroto
Published: April 2006

A highly sensitive chemiluminescence (CL) method was developed for the determination of ascorbic acid (AA) based on the conversion of AA to hydrogen peroxide (H2O2) in a cationic reverse micellar hexadecyltrimethylammonium chloride : chloroform medium. AA was indirectly determined by measuring the H2O2 generated by the peroxyoxalate CL method. The CL intensity was linearly correlated with AA concentration over the range from 5.0 × 10−8 to 1.0 × 10−6 M.
Inclusion Compounds of Cholic Acid with Various Hydrocarbons and the Crystal Structure of a 1 : 1 Complex of Cholic Acid and Benzene
Authors: Nakano Kazunori , Sada Kazuki , Miyata Mikiji
Published: April 2006

Cholic acid was found to form crystalline inclusion compounds with various hydrocarbons and related compounds. Some alcohols do not form inclusion crystals at all, but serve as solvents. The crystal structure of a 1 : 1 inclusion compound of cholic acid with benzene was determined. Comparative studies on inclusion behaviors of cholic acid and deoxycholic acid are now possible.
Construction of a Chiral Quaternary Carbon Center via 1,2-Acyl Migration of an Optically Active α,β-Epoxy Ketone
Authors: Okada Kunisuke , Katsura Toshiyuki , Tanino Hideo , Kakoi Hisae , Inoue Shoji
Published: April 2006

The construction of a chiral building block with a quaternary carbon center is described, based on the Lewis acid-catalyzed acyl migration of α,β-epoxy ketone with alkyl and alkenyl substituents.
Structural Change in Lithium Intercalation of Layered Perovskite LiLaNb2O7
Authors: Sato Mineo , Jin Tetsuro , Ueda Hirokazu
Published: April 2006

The chemical lithium intercalation of a layered perovskite LiLaNb2O7 compound has been performed by using n-butyllithium. The content of inserted lithium ions was found to be ca. 1 mol per unit formula. The crystal structure of the intercalated compound was determined by the powder X-ray diffraction pattern. An unusual contraction of the cell volume inherent in the intercalation reaction was observed.
Synthesis of a Cyclodextrin Heterodimer Having α- and β-Cyclodextrin Units and Its Cooperative and Site-Specific Binding
Authors: Wang Yong , Ueno Akihiko , Toda Fujio
Published: April 2006

A cyclodextrin heterodimer, which has α- and β-cyclodextrin units as two different receptor sites, was prepared. It showed cooperative and site-specific binding to isoamyl p-dimethylaminobenzoate with the alkyl group included in the β-cyclodextrin cavity while dimethylaminobenzene moiety partially included in the α-cyclodextrin cavity. This binding mode was substantiated by the fact that the TICT emission of this guest is greatly enhanced by the cyclodextrin heterodimer.
Helical Chirality and Enantiotopomerization Process of a Photochromic Furylfulgide
Authors: Yokoyama Yayoi , Iwai Takeshi , Yokoyama Yasushi , Kurita Yukio
Published: April 2006

A photochromic furylfulgide, (E)-2-[1-(2,5-dimethyl-3-furyl)-2-methylpropylidene]-3-isopropylidenesuccinic anhydride, was shown to be chiral. Its enantiotopomerization process was observed by variable temperature 1H NMR measurement, and ΔH≠(obs) was 52.9 ± 8.1 kJ mol−1. AM1 calculation showed ΔH≠(calc) to be 51.5 kJ mol−1.
In-situ EXAFS Observation of the Molecular Reaction Intermediate for NO–H2 Reaction on Highly Active Rh–Sn/SiO2 Catalysts
Authors: Tomishige Keiichi , Asakura Kiyotaka , Iwasawa Yasuhiro
Published: April 2006

In-situ EXAFS technique was successful by applied for the first time to observe the molecular reaction intermediate for NO–H2 reaction on highly active Rh–Sn/SiO2 catalysts. The EXAFS data, with the aid of FTIR, revealed the existence the bent-type NO with the bond distance of 0.256 nm with Sn atoms (Rh–NO···Sn) on the bimetallic surface in the steady-state reaction conditions. The tilted NO was dissociated to form Sn–O bond at 0.205 nm.
Spectral Cosensitization in Organic Solar Cell with Mixed Film of Zinc Porphyrin and Merocyanine
Authors: Takahashi Kohshin , Hashimoto Kei , Komura Teruhisa , Murata Kazuhiko
Published: April 2006

The Al/dye/Au sandwich-type photovoltaic cell with a mixed solid of 5,10,15,20-tetraphenylporphyrinatozinc (Zntpp) and 3-ethyl-5-[(3-ethyl-2(3H)-benzothiazolylidene)ethylidene]-2-thioxo-4-thiazolidinone (MC) exhibits a remarkably large energy conversion yield and a better spectral match with a solar spectrum, compared with a pure Zntpp or a MC solid.
Chiral Discrimination of Monosaccharides through Gel Formation
Authors: James Tony D , Murata Kazutaka , Harada Takaaki , Ueda Keiko , Shinkai Seiji
Published: April 2006

The cholesterylphenylboronic acid (1) and its complexes with mono saccharides (2 : 1; 1/monosaccharide) were prepared. Many of the isolated complexes form gels in a variety of solvents, some of which display D vs L chiral discrimination. This is the first example of chiral discrimination in a saccharide based gel system.
Study on the Nuclear Reactions of 93Nb, 181Ta, and 197Au Induced by Secondary Neutrons in 40 MeV/nucleon 40Ar Ion Collisions
Authors: Li Wenxin , Ohkubo Yoshitaka , Ambe Shizuko , Kobayashi Yoshio , Iwamoto Masako , Maeda Haruka , Ambe Fumitoshi
Published: April 2006

Nuclear reactions of 93Nb, 181Ta, and 197Au induced by secondary neutrons produced by irradiation of a thick stainless steel target with 40 MeV/nucleon 40Ar ions were investigated by off-line γ-ray spectroscopy. Yields of the radioactive products have been determined relative to that of 24Na produced by the 27Al(n,α)24Na reaction. The slopes of the mass distributions deduced from the experimental data are independent of the target species. Up to 7 nucleons were removed from the target nuclei, indicating significant presence of the neutrons with energies higher than 70 MeV.
Complex Formation between Iron(III) and Tartaric and Citric Acids in a Wide pH Range 1 to 13 as Studied by Magnetic Susceptibility Measurements
Authors: Yokoi Hiroshi , Mitani Tsuyoshi , Mori Yasuyoshi , Kawata Satoshi
Published: April 2006

Computer simulation analysis of the experimental plots of effective magnetic moment against pH for aqueous solutions of iron(III) and either l-tartaric acid or citric acid at different concentration ratios has first given the whole aspect of complex formation in a wide pH range 1 to 13 at room temperature. Formation of various kinds of poly- and mono-nuclear complexes has been elucidated in these solutions.
Synthesis and Properties of Germylene-Bridged Diiron Complexes Using t-Butylgermane as a Precursor of Ligands
Authors: Kawano Yasuro , Sugawara Keiko , Tobita Hiromi , Ogino Hiroshi
Published: April 2006

Photolysis of CpFe(CO)2SiMe3 (Cp = η-C5H5) in the presence of a new alkylgermane tBuGeH3 afforded a mono(μ-germylene)diiron complex Cp2Fe2(CO)3(μ-GeHtBu) (4) and a bis(μ-germylene)diiron complex Cp2Fe2(CO)2(μ-GeHtBu)2 (5). The structure of 4 was determined by X-ray crystallography.
The Stereoselective Synthesis of Trisubstituted Olefins by the Reaction of (2-Phenylthiocyclobutyl)methyl Benzoates and Methyl Ethers with Silyl Nucleophiles
Authors: Fujiwara Tooru , Iwasaki Toshiaki , Miyagawa Jun , Takeda Takeshi
Published: April 2006

The Lewis acid-promoted reaction of 2-phenylthiocyclobutanemethanol derivatives with silyl nucleophiles gave the corresponding trisubstituted olefins with high stereoselectivity in good yields. It is suggested that the reaction proceeds via the thionium ion intermediate.
New Intramolecular Five-Endo-Mode Cyclization of Allenyl Aryl Ketones
Authors: Nagao Yoshimitsu , Lee Woo-Song , Kim Kweon
Published: April 2006

A convenient preparation of allenyl aryl ketones was achieved by the Weinreb-modified Grignard reaction of N-methoxy-N-methylamides with propargylmagnesium bromide. On treatment with BF3·OEt2, the allenyl aryl ketones were converted to methylenebenzocyclopetenones via a new 5-endo-mode cyclization.
Stabilized Zirconia Based CO2 Sensors Combined with Carbonate Auxiliary Phase
Authors: Miura Norio , Yan Yongtie , Sato Masaki , Yao Sheng , Shimizu Youichi , Yamazoe Noboru
Published: April 2006

A solid-state electrochemical CO2 sensor was fabricated by combining an MgO-stabilized zirconia (MSZ) tube and Li2CO3 auxiliary phase. The sensor responded very well to 100–1000 ppm CO2 in air at 400–600 °C, with its EMF responses following the Nernst’s equation for the 2-electron reduction of CO2. It was also possible to fabricate an MSZ-based planar-type sensor, which gave stable EMF responses to CO2 regardless of variations in O2 concentration. The CO2 sensing mechanism of these sensors was briefly discussed.
Poly(thiophene-2,5-diyl) Having Crown Ethereal Subunit. Preparation, Stable n-Doped State, and Light Emitting Diode
Authors: Miyazaki Yuichi , Yamamoto Takakazu
Published: April 2006

π-Conjugated polythiophene having crown ethereal subunit, PCT5, reacts with metallic Na to afford a Na-doped or n-doped semiconducting material, which shows good stability against O2 in air presumably due to strong interaction between Na+ and the crown ethereal subunit. An ITO | PCT5 | Al electric junction serves as a light emitting diode, which starts to emit light at 6 V.
Hydrogenation of Biphenyls over the Hydrogen Storage Alloy MmNi3.5Co0.7Al0.8H4
Authors: Nakagawa Shin-ichi , Murata Satoru , Sakai Tetsuo , Nomura Masakatsu
Published: April 2006

Hydrogenation of biphenyl with the activated hydrogen storage alloy, MmNi3.5Co0.7Al0.8H4 (Mm: La, 30; Ce, 52; Pr, 5; Nd, 13 wt%), as a stoichiometric reductant proceeded effectively at 160 °C for 3 h under nitrogen to give either phenylcyclohexane or bicyclohexyl selectively, according to the ratio of the alloy to biphenyl.
Tin(II) Chloride Catalyzed Synthesis of Ribofuranosides
Authors: Shimomura Naoyuki , Saitoh Masahiro , Mukaiyama Teruaki
Published: April 2006

Catalytic synthesis of several d-ribofuranosides from 2,3,5-tri-O-benzyl-1-O-iodoacetyl-d-ribofuranose and trimethylsilylated nucleophiles such as 3β-cholestanyl trimethylsilyl ether and phenyl trimethylsilyl sulfide is efficiently promoted by tin(II) chloride under mild conditions. When allyltrimethylsilane, azidotrimethylsilane, etc., are used as nucleophiles, combined use of catalytic amounts of SnCl2 and SiCl4 also afforded the corresponding ribofuranosides in good yields.
A New Thermo-Sensitive Fatty Acid Complex. The Mechanism and Its Applicability to a Drug Delivery System
Authors: Yokoyama Shoko , Sunohara Masaaki , Fujie Tadao , Hasegawa Makoto , Abe Masahiko
Published: April 2006

A thermo-sensitive fatty acid-drug crystalline complex was prepared. The mechanism for the thermo-sensitivity was investigated by the powder X-ray diffractometry and the infrared spectroscopy, and its applicability to a thermo-responsive drug delivery system was discussed.
Synthesis of Higher-nuclearity Clusters by Use of Small Cluster Units as Building Blocks. Syntheses and X-Ray Analyses of p-[Co3(CO)9C]2C6H4 and [CH3CCo3(CO)8]2(μ-dppfe)
Authors: Onaka Satoru , Otsuka Mayumi , Mizuno Atushi , Takagi Shigeru , Sako Katsuya , Otomo Makoto
Published: April 2006

Two units of -CCo3 trinuclear cluster are systematically incorporated into various spacer molecules such as p-C6H4- and 1,1′-bis(diphenylphosphino)ferrocene, dppfe. X-Ray structure analysis has been made for p-[Co3(CO)9C]2-C6H4 (1) and [CH3CCo3(CO)8]2(μ-dppfe). Electronic interaction between two cluster units in 1 has been asserted by X-ray and absorption data.
Amination of o-Alkenylphenols with Alkylamines via Photoinduced Proton Transfer
Authors: Yasuda Masahide , Sone Tatsuya , Tanabe Kimiko , Shima Kensuke
Published: April 2006

Irradiation of o-alkenylphenols with alkylamines resulted in Markovnikov-type amination to give o-(1-alkylaminoalkyl)phenols in relatively good yields. The photoamination was initiated by a proton transfer from the ammonium ion to the alkenyl group of o-alkenylphenolate anion in the excited state in the ion pair formed between the phenols and the amines. The resulting zwitter ion allowed the nucleophilic addition of the amine at the benzylic cation center.
Regioselective Synthesis of 1,2- and 1,3-Bridged Calix[4]crowns. What Are the Factors Controlling the Regioselectivity?
Authors: Yamamoto Hiromasa , Sakaki Toru , Shinkai Seiji
Published: April 2006

The product distribution in the synthesis of calix[4]crowns from calix[4]arene-25,26,27,28-tetrol and 3,6-dioxaoctane-1,8-ditosylate was investigated in detail. It was shown that the 1,2- vs. 1,3-bridging regioselectivity is governed by the basicity and the metal cation of the used base. The findings enable us to regioselectively synthesize desired calix[4]crowns in good yields, which has been believed to be too difficult to control.
Improvement of CAPCIUS Cell Using SrCe0.95Yb0.05O3−α as a Solid Electrolyte
Authors: Hibino Takashi , Asano Koichi , Iwahara Hiroyasu
Published: April 2006

The CAPCIUS cell was improved using SrCe0.95Yb0.05O3−α as a solid electrolyte. When the operating temperature was 950 °C and the thickness of SrCe0.95Yb0.05O3−α ceramic was 0.5 mm, the maximum power density was 21 mW cm−2, which was about 10 times value observed in the CAPCIUS cell using YSZ with the same thickness as a solid electrolyte. The mechanism for the improvement was studied by various electrochemical techniques.
A New Type of Kinetic Equation for Crystal Growth Which Can be Applicable to the Second Step of a Two-Step Crystallization of Calcium Hypochlorite Dihydrate
Authors: Murakami Tsugio , Tsuchiya Susumu
Published: April 2006

The equation, dla/dt = k Cs exp (−b la), newly proposed can well express the rate of crystal growth in the second step of two-step crystallization of calcium hypochlorite dihydrate.
Magnetic Field Effects on Hydrogen Abstraction of Triplet Benzophenone with Thiophenol in an SDS Micellar Solution
Authors: Wakasa Masanobu , Sakaguchi Yoshio , Hayashi Hisaharu
Published: April 2006

The photoreduction of benzophenone with thiophenol was studied by a laser flash photolysis under the magnetic fields of 0–10 T. The escape yields of the benzophenone ketyl and phenylthiyl radicals decreased with increasing magnetic field strength. The observed magnetic field effect can be interpreted by the Δg mechanism in the case of a triplet radical pair.
Palladium-Catalyzed Aminocarbonylation of Cinnamyl N,N-Dialkylcarbamates. An Intriguing Crossover with p-Methylcinnamylamines
Authors: Miyazawa Masahiro , Yamamoto Keiji
Published: April 2006

Competition experiments in the palladium-catalyzed aminocarbonylation of cinnamyl N,N-dialkylcarbamates with p-methylcinnamylamines revealed that the allylamine did not undergo oxidative addition but attacked extensively a π-allylpalladium which arose from the allyl carbamate under the conditions employed, forming a mixture of the corresponding amides containing either cinnamyl moiety that incorporates a dialkylamino component originated only from the carbamate.
Synthesis of Dimethyl Garbonate by Electrolytic Carbonylation of Methanol in the Gas Phase
Authors: Otsuka Kiyoshi , Yagi Toshikazu , Yamanaka Ichiro
Published: April 2006

Electrolytic carbonylation of methanol has been attempted in the gas phase under atmospheric pressure at 343 K. The graphites added with PdCl2 and CuCl2 are favorable anodes for the synthesis of dimethyl carbonate (DMC). The formation of DMC occurs at a lower applied voltage than that for dimethoxy methane and methyl formate. However, a considerable CO2 formation accompanies the DMC formation.
Reactions and Kinetics of (2,4,6-Tri-tert-butylphenyl)phenylcarbene
Authors: Hirai Katsuyuki , Komatsu Kazunori , Tomioka Hideo
Published: April 2006

The title carbene generated by photolysis of the corresponding diazo compound at room temperature gave 4,6-di-tert-butyl-1,1-dimethyl-3-phenylindan quantitatively. Triplet states of the carbene were observed by laser flash photolysis of the diazo compound in the presence of benzophenone as a triplet sensitizer.
Preparation of Anti-Pyrenyl Antibody and Its Chiral Recognition against a Nonnatural Amino Acid Carrying Pyrenyl Group
Authors: Imaizumi Mitsuhiro , Sisido Masahiko
Published: April 2006

Monoclonal antibody was raised against a tetrapeptide containing l-pyrenylalanine. The antibody bound the tetrapeptide as well as l-pyrenylalanine methyl ester, indicating that it recognizes the pyrenyl group. The antibody, however, did not bind d-pyrenylalanine methyl ester. This finding suggests a potentiality of monoclonal antibodies for chiral separations.
A Useful Method for the Preparation of Carboxylic Esters from Free Carboxylic Acids and Alcohols
Authors: Shiina Isamu , Miyoshi So , Miyashita Mitsutomo , Mukaiyama Teruaki
Published: April 2006

Various carboxylic esters are prepared in excellent yields from nearly equimolar amounts of free carboxylic acids and alcohols at room temperature by combined use of 4-(trifluoromethyl)benzoic anhydride and a catalytic amount of active titanium(IV) salt together with chlorotrimethylsilane.
Dicarboxylic Acids in the Murchison and Yamato-791198 Carbonaceous Chondrites
Authors: Shimoyama Akira , Shigematsu Ryusuke
Published: April 2006

Dicarboxylic acids were recovered in the C2 to C9 range in concentration about 2000 to 0.1 nmol/g from the Murchison and Yamato-791198 carbonaceous chondrites. The molecular distributions of the saturated straight-chain acids suggest that they approximately show their original compositions when they were formed in the early solar system. Optical isomers of the acids were found to be racemic.
Oxidation of Diols with Sodium Bromite Trihydrate in Organic Solvents in the Presence of Alumina
Authors: Morimoto Takashi , Hirano Masao , Iwasaki Keiko , Ishikawa Takashi
Published: April 2006

The title oxidation of diols with two primary hydroxy groups (symmetrical diols) and those with both a primary and a secondary hydroxy group (unsymmetrical diols) gives the corresponding lactones or the hydroxy ketones, being dependent upon the types of diols.
Porphyrins Containing Aziridinyl-p-Benzoquinone Substituents
Authors: Palka Anna , Czuchajowski Leszek
Published: April 2006

New porphyrins containing aziridinyl-p-benzoquinone meso-substituents were synthesized. They were designed to be specific DNA cross-linkers and alkylating agents.
Reversing-pulse Electric Birefringence of Montmorillonite Particles Suspended in Aqueous Media
Authors: Yamaoka Kiwamu , Sasai Ryo , Ikuta Natsuki
Published: April 2006

Reversing-pulse electric birefringence of montmorillonite was measured in aqueous media at 25 °C and at 633 nm. The counterion for this clay was either Na+ or Mg2+. The electric field orientation of the disk-shaped particle was due to ion-induced dipole moments but not due to permanent dipole moment.
Z- and threo-Selective 1-Methyl-2-butenylation of Aldehydes by 4-(Tributylstannyl)-2-pentene
Authors: Miyake Hideyoshi , Yamamura Kimiaki
Published: April 2006

Transmetallation of an E,Z-mixture of 4-(tributylstannyl)-2-pentene with BuSnCl3 proceeded stereoselectively to give (E)-4-(butyldichlorostannyl)-2-pentene (3). The subsequent addition of it to an aldehyde proceeded Z- and threo-selectively to give 1-methyl-2-butenylated product.
New Xanthic Acid Derivative as Selective Reagent for the Solvent Extraction of Palladium
Authors: Chowdhury Didarul Alam , Kamata Satsuo
Published: April 2006

Trimethylene-bis(n-butyl)xanthate (TrMBnBX) has been synthesized as a new sulfur-containing reagent for the extraction of precious metal ions. This compound exhibited high selectivity for extraction of Pd(II) and Ag(I) ions in dichloroethane, over Pt(IV), Au(III) and most of the base metal ions. A mixed aqueous system containing H2SO4 in presence of small amount of chloride ions provides the maximum extraction of Pd(II), where it forms a 1:1 complex with TrMBnBX.
New Six- to Eight-Membered-Ring Formation Based on the lntramolecular Endo-Mode Ring Closure of Allenyl (Substituted Phenyl)alkyl Ketones
Authors: Nagao Yoshimitsu , Lee Woo Song , Komaki Yoichi , Sano Shigeki , Shiro Motoo
Published: April 2006

Several allenyl ketones possessing an aryl group were submitted to a new intramolecular endo-mode cyclization with BF3·OEt2 or TiCl4 in CH2Cl2 to afford the corresponding 6-, 7-, and 8-membered carbocyclic products.
Facile Synthesis of 5-Substituted Arabinofuranosyluracil Derivatives
Authors: Sawai Hiroaki , Hayashi Hidekazu , Sekiguchi Sumie
Published: April 2006

Arabinoaminooxazoline reacted readily with α-(bromomethyl)acrylate derivatives to afford the corresponding adduct. Potassium tert-butoxide- or sodium methoxide-catalyzed cyclization of the adduct gave 5-substituted 2,2′-anhydroarabinofuranosyluracil derivatives.
Facile Syntheses of cis-Fused Carbobicycles via Combination of Claisen Rearrangement of Macrolactone and Nitrile Oxide Cycloaddition
Authors: Suh Young-Ger , Kim Soon-Ai , Cho Hyun-Uk , Cho Youn-Sang
Published: April 2006

cis-Bicyclo[3.3.0]octanone, cis-hydrindanone and cis-decalone skeletons have been efficiently constructed by intramolecular nitrile oxide-olefin cycloaddition of 1-ethenyl-2-nitroalkyl cycloalkanes or 1-ethenyl-2-hydroxyiminoalkyl cycloalkane which are readily derived from macrolactone by Funk’s Claisen rearrangement.
Syntheses, Structures, and Some Reactions of Di-μ-Hydroxo Dinuclear Complexes of Tungsten(IV) and Molybdenum(IV)
Authors: Ren Jian-Guo , Tomita Hideshi , Minato Makoto , Osakada Kohtaro , Ito Takashi
Published: April 2006

Novel dinuclear complexes [Cp2M(μ-OH)2MCp2]2+(OTs−)2 (M = Mo and W) were prepared by the reaction of Cp2MH2 with Cp2M(OTs)2 in aqueous acetone. Their structures were characterized by spectroscopic methods as well as by X-ray crystallography. The structure comprises a planar four membered ring consisting of alternating M and O atoms.
Iron Chelates in Biological Systems. Its Relevance to lnduction of Pathogenesis of Tissue Damage and Carcinogenesis
Authors: Nishida Yuzo , Goto Atsuko , Akamatsu Tetsuya , Ohba Shigeru , Fujita Toyoaki , Tokii Tadashi , Okada Shigeru
Published: April 2006

Iron-nta(nitrilotriacetate) solution induces severe nephrotoxicity and high accidence of renal carcinoma in rats and mice, however, the effect by an iron-pac(2-aminomethylpyridine-N,N-diacetate) solution is negligible. These facts were interpreted in terms of different reactivity of the two compounds toward hydrogen peroxide.
Scanning Near-field Fluorescence Microscopy and Nanoscopic Fluorescence Spectroscopy in Combination with a Non-contact Scanning Force Microscope
Authors: Fujihira Masamichi , Monobe Hirosato , Muramatsu Hiroshi , Ataka Tatsuaki
Published: April 2006

The resolution of scanning near-field optical microscopy (SNOM) is determined by the dimensions of the microscopic light source (or detector) and the probe-to-sample separation rather than the diffraction limit. In the present microscope, we took advantage of scanning force microscopy (SFM) with a vibrating cantilever holding an optical fiber tip not only to give a simultaneous SFM topographic image but also to control the separation for SNOM without mechanical damages of the sample. By the precise control of the separation of the tip within 100 nm from the sample surface, we demonstrate here that this combined non-contact SFM and SNOM method can be used as fluorescence microscopy and nanoscopic fluorescence spectroscopy with a resolution of ∼100 nm.
Purification and Substrate Specificity of Chlorophyllase from Chlorella regularis
Authors: Nishiyama Yoshitaka , Kitamura Masaya , Tamura Sayuri , Watanabe Tadashi
Published: April 2006

Chlorophyllase was purified 13300-fold from a crude butanol extract of Chlorella regularis. The enzyme clearly recognizes the C132 stereochemistry of chlorophyllous pigments in that it hydrolyzes the a and b (132R) forms but not the a′ and b′ (132S) forms. No enzyme was detected in vivo that specifically hydrolyzes chlorophyll a′.
Effect of Vitamin B12 Treatment on Haptocorrin
Authors: Mørkbak Anne L , Hvas Anne-Mette , Lloyd-Wright Zouë , Sanders Tom AB , Bleie Øyvind , Refsum Helga , Nygaard Ottar K , Nexø Ebba
Published: April 2006

Background: Haptocorrin (HC) carries the major part of circulating cobalamin, but whether HC is altered on treatment with vitamin B12 remains unknown.

Methods: Our study included 3 populations: a population of vegan men (n = 174; vegan population), of whom 63 were treated daily with 5 mg of oral vitamin B12 for 3 months; a group of patients with a previous methylmalonic acid (MMA) concentration >0.4 μmol/L (n = 140; population with suspected deficiency), of which 69 were treated with weekly vitamin B12 injections (1 mg) for 4 weeks; and a subgroup of participants in a vitamin B intervention study (n = 88; nondeficient population), of whom 45 were treated daily with 0.4 mg of oral vitamin B12 for 3 months. Total HC and holoHC were measured by ELISA. Cobalamin was measured by an intrinsic factor (IF)-based assay. Samples were collected at baseline and 3 months after start of treatment.

Results: Compared with baseline results for the 3 study populations, total HC and holoHC increased 30 pmol/L for every 100 pmol/L increase in cobalamin. After treatment with vitamin B12, holoHC (P <0.0001) and total HC (P <0.0001) increased significantly in the vegan population. Only holoHC increased in the population with suspected deficiency (P <0.0001), whereas no alteration was observed in the nondeficient population.

Conclusions: The HC concentration is decreased in severely cobalamin-deficient individuals and increases on treatment. The concentration of cobalamin also relates significantly to the HC concentration in nondeficient individuals.