bluuebunny/crossref_metadata_2025 huggingface dataset:
The Chinese in Spain
Authors: Nieto Gladys
Published: September 2003

During the past 15 years, the Chinese migrant community in Spain has grown significantly. Originally a small and dispersed population, it now ranks fourth among the migrant groups from non‐European Union (EU) countries. Its increasing presence in daily urban life is evident everywhere. Even though the Chinese community has a long history of settlement in Spain, the Spanish population still considers the Chinese as a closed and somewhat mysterious community. References to exaggerated stereotypes and prejudices regarding their activities and social organization can often be overheard in daily conversations. However, China, usually considered exotic and remote, has recently assumed greater importance in Spain's foreign policy. Thus, the Spanish Government has drawn up the Asia‐Pacific Framework Plan for 2000–2002 as part of its international policy considerations, thereby extending its interests to include areas well beyond its traditional foreign policy focus on Latin America. The Government's objectives are to expand its economic relations with Asia, to enhance trade and tourism with the area, expand the development cooperation with China, the Philippines, and Viet Nam — countries defined as top priorities for the Spanish Government — and to reinforce linguistic and cultural ties with these countries (Bejarano, 2002). In support of the Asia‐Pacific Framework Plan, the Casa Asia (House of Asia) was established in Barcelona in 2002, an institution created to organize academic and artistic activities in order to promote the knowledge of the region among Spaniards, and to foster political, economic, and cultural relations with Asia.

The Government intends to pursue two important objectives related to the increasing commitments it is seeking to establish with China, and which are also of relevance to the overseas Chinese as the principal social actors involved. First, the strengthening of commercial exchanges with the People's Republic of China (PRC) are likely to benefit import‐export activities among the Chinese migrants, and be supported by their knowledge and practical experience of the respective social environments. Second, the dissemination of information on Spain is expected to establish and maintain stronger links in both directions. In the near future, these initiatives may also be instrumental in increasing the movement of people between China and Spain. Besides these primary objectives, the initiative pursues another important aim — the promotion of the social integration of the Chinese migrant community in the country.

This paper addresses these issues, including data sources and their availability on Chinese migrants in Spain, the relevant local legal framework and how it influences the development of the Chinese migrant group, its sociodemographic composition, and migratory patterns. Finally, it addresses the changes in their economic activities.
Perceiving and experiencing fictional characters: An integrative account1
Authors: Hoorn Johan F. , Konijn Elly A.
Published: September 2003

Abstract:  Fictional characters (FCs) and mediated persons in literature, theater, film, art, TV, and digital media fulfill basic psychological functions, although the processes involved remain unspecified. Departing from identification and empathy hypotheses, a new context‐sensitive model draws upon similarity studies, empirical aesthetics, persuasion, emotion, and social psychology. The Perceiving and Experiencing Fictional Characters model (PEFiC‐model) has three phases. During encoding, observers judge FCs in terms of ethics (good‐bad), aesthetics (beautiful‐ugly), and epistemics (realistic‐unrealistic). Comparison entails appraisals of personal relevance as well as valence towards and (dis)similarity between the dramatis personae and the self. In the response phase, appreciation of FCs is a trade‐off between the parallel, unipolar processes of involvement and distance. Intricate involvement‐distance conflicts occur when subjective norms disagree with ingroup norms. Furthermore, features participate in multiple (fuzzy) sets (e.g., partly good and partly bad). PEFiC can handle complex responses towards representations of (non‐existent) others, such as attractive dissimilarity, the beauty in ugliness, the appeal of negative experiences, and fascination for evil, as well as mixed emotions, ambivalence, and neutral end‐states that actually conceal emotional confusion.
Research for d eterminant factors and features of emotional responses of “kandoh” (the state of being emotionally moved)
Authors: Tokaji Akihiko
Published: September 2003

Abstract: The feature and determinants of the emotional response kandoh (the state of being emotionally moved) were positively examined (kandoh has rarely been made the object of research in the field of psychology). First, the author reviewed the research done so far and summarized the features of kandoh, and the structural model of the process leading to kandoh was introduced from the results of the above research. Furthermore, experimental examination about the model was performed of different types of stories, and even stories with opposing the emotional frameworks of happiness or sadness, both were shown that they were able to become heart‐warming good stories. Moreover, it was shown that the event‐related knowledge was important for evocation of kandoh. From the experiment results, consideration was made about new aspects of kandoh.
Constructive perception: Coordinating perception and conception toward acts of problem‐finding in a creative experience1
Authors: Suwa Masaki
Published: September 2003

Abstract: Fostering better performance in a creative experience is an issue in every institution of design or art. What aspect does a creative experience possess and what kind of cognitive processes constitute it? How should students be trained to entertain the use of cognitive skills, if any, in building up a creative experience of their own? The purpose of the present paper is to examine these issues to lay the foundation for the pedagogy of a creative experience. Examining the cognitive processes of an experienced architect, we found that a creative experience has the aspect of problem‐finding; an act of formulating one's own problems and resolving them rather than just solving a presented problem. Further, we found that a coordination of both perceptual reorganization and conceptual generation constitutes an act of problem‐finding in a creative experience. Experiments using ambiguous drawings have shown that coordinating one's own perception and conception for inventing novel interpretations requires a cognitive skill, what we call the skill of constructive perception; that is, to be self‐aware of the way perception underlies the current interpretation and thereby reorganize perception and generate novel interpretations. How to help students master this skill and how to design educational programs to allow for accomplishment of acts of problem‐finding will be discussed.
Numerical Calculation of Interaction Between the Ferromagnetic Dots and Vortices
Authors: Cheng Bo , Ragsdale Tony , Yeh W. J.
Published: September 2003

Enhancing the pinning force in high-Tc superconductors can be achieved by externally introduced periodic magnetic dots. We have numerically calculated the interaction between the magnetic dot and the vortex in high-Tc superconductors. The London equation is used to generate two-dimensional vortex lattice. In the matching condition, we calculate the attraction force between the magnetic dots and vortices at various conditions. It is found that the magnitude of the pinning from the dots is compatible with the intrinsic pinning force of YBCO thin film materials.
A Ring Silencer Design for Reducing Noise of Axial Fan
Authors: Wu Jian-Da , Bai Mingsian R.
Published: September 2003

In this paper, a ring silencer design for reducing the noise of axial fans is presented. The noise sources on axial fans are usually caused by the fluctuating pressure distribution on the surface of fan blade. Most of the sources are near the trailing edge of blades or boundary region of blades. The ideation of proposed design is based on the principle of Helmholtz resonator for reducing the noise around the fan. The electro-acoustic analogy of this design is presented and simply discussed. Experimental measurement is carried out to evaluate the proposed design for reducing the axial fan noise. The result of experiment indicated that the ring silencer achieved 17 dB in blade passing frequency and 10 dB in other broadband frequency of power spectrum level.
Novel role of the membrane-bound chemokine fractalkine in platelet activation and adhesion
Authors: Schäfer Andreas , Schulz Christian , Eigenthaler Martin , Fraccarollo Daniela , Kobsar Anna , Gawaz Meinrad , Ertl Georg , Walter Ulrich , Bauersachs Johann
Published: September 2003

Chemokines released by the endothelium have proaggregatory properties on platelets. Fractalkine, a recently discovered membrane-bound chemokine with a transmembrane domain, is expressed in vascular injury; however, the effects of fractalkine on platelets have not yet been investigated. Blood was taken from healthy Wistar-Kyoto rats and the expression of the fractalkine receptor on platelets was demonstrated. The modulation of surface expression of P-selectin was assessed by flow cytometry. P-selectin expression was significantly enhanced by in vitro stimulation with recombinant rat fractalkine compared with baseline levels. Selectively inhibiting the function of recombinant fractalkine by an antagonizing antibody or the disruption of the G-protein–coupled intracellular signaling cascade of the fractalkine receptor by pertussis toxin (PTX) completely prevented fractalkine-mediated platelet activation. Preincubation with apyrase significantly attenuated the fractalkine-induced degranulation. In a flow chamber model of platelet adhesion, stimulation with fractalkine significantly enhanced platelet adhesion to collagen and fibrinogen. Similar to P-selectin expression, enhanced adhesion could be prevented by the antagonizing antibody or preincubation of platelets with PTX. Fractalkine, which is overexpressed in atherosclerosis and vascular injury, contributes to platelet activation and adhesion and hence is likely to play a pathophysiologically important role for increased thrombogenesis in vascular diseases.
Telomerase inhibition with an oligonucleotide telomerase template antagonist: in vitro and in vivo studies in multiple myeloma and lymphoma
Authors: Wang Eunice S. , Wu Kaida , Chin Allison C. , Chen-Kiang Selina , Pongracz Krisztina , Gryaznov Sergei , Moore Malcolm A. S.
Published: September 2003

The effects of telomerase inhibition with an oligonucleotide N3′ → P5′ thiophosphoramidate (GRN163) complementary to the telomerase template region were examined on human multiple myeloma (MM) and non-Hodgkin lymphoma (NHL) cell lines, primary MM cells, and tumor xenografts. GRN163 treatment reduced telomerase levels in all cells and induced more rapid telomeric shortening. Continuous GRN163 treatment for 7 to 14 days resulted in proliferative arrest, morphologic changes, and apoptosis characteristic of cell crisis in tumor cell lines with short (1.7-5.4 kb) but not long (9-11 kb) telomeres. Intratumoral administration of GRN163 also inhibited the growth of MM and NHL xenografts established from cell lines with short telomeres (Hs602 lymphoma, 2.7 kb; CAG myeloma, 2.7 kb) and increased tumor apoptosis. However, GRN163 therapy of NHL xenografts established from cells with long telomeres (11.0 kb) had equivocal effects on tumor growth and did not induce apoptosis during this time frame. Systemic daily intraperitoneal administration of GRN163 in myeloma xenografts with short telomere lengths also decreased tumor telomerase levels and reduced tumor volumes. These data demonstrate that telomerase is important for the replication of mature B-cell neoplasia by stabilizing short telomeres, and they suggest that telomerase inhibition represents a novel therapeutic approach to MM and NHL.
Transcriptional coactivation of c-Jun by the KSHV-encoded LANA
Authors: An Jiabin , Sun Yiping , Rettig Matthew B.
Published: September 2003

The Kaposi sarcoma–associated herpesvirus (KSHV)–encoded latency-associated nuclear antigen (LANA) modulates viral and cellular gene expression, including interleukin 6 (IL-6), a growth factor for KSHV-associated diseases. LANA-driven IL-6 expression is dependent on the activator protein 1 (AP1) response element (RE) within the IL-6 promoter. We show that LANA activates the AP1 RE in a Jun-dependent fashion and that LANA enhances the transcriptional activity of a GAL4-Jun fusion protein. Coimmunoprecipitation studies documented a physical interaction between LANA and c-Jun in transiently transfected 293 cells as well as the KSHV-infected BCBL-1 primary effusion lymphoma (PEL) cell line. Taken together, these data indicate that LANA is a transcriptional coactivator of c-Jun. In addition, electrophoretic mobility shift assays demonstrated that LANA induces binding of a c-Jun-Fos heterodimer to the AP1 RE, but does not itself bind to the AP1 RE. RNA interference experiments confirmed that LANA activates the AP1 RE, stimulates binding of a c-Jun-Fos heterodimer to the AP1 RE, and induces expression of IL-6. These data indicate that LANA is a transcriptional coactivator of c-Jun, a function that may have implications for the pathogenesis of KSHV-associated diseases.
Telehematology: critical determinants for successful implementation
Authors: Luethi Urs , Risch Lorenz , Korte Wolfgang , Bader Margrit , Huber Andreas R.
Published: September 2003

Despite modern technologies, such as immunophenotyping and molecular probing, cytomorphologic examination of stained peripheral blood smears by microscopy remains the mainstay of diagnosis in a large variety of diseases. This holds true especially in underdeveloped or rural areas where profound expertise and equipment are not easily available. Although communication technologies have been dramatically improved, telehematology has not become routine. To date, little information is available on which procedures are critical for successful implementation. Therefore, a study evaluating possible factors that prevented implementation of telehematology was initiated. We found that staining technique, smearing procedure, training skills, number of captured images, and prevalent disease influenced the accuracy of diagnosis by the reference laboratory. Using realtime teleconferencing allowed for overcoming these deficits. Together, when certain rules are observed, telehematology allows for rapid, accurate, standardized, and cheap expert advice. This technology should improve treatment of patients in remote areas where expertise is not available.
Xrx1controls proliferation and neurogenesis inXenopusanterior neural plate
Authors: Andreazzoli Massimiliano , Gestri Gaia , Cremisi Federico , Casarosa Simona , Dawid Igor B. , Barsacchi Giuseppina
Published: September 2003

In Xenopus neuroectoderm, posterior cells start differentiating at the end of gastrulation, while anterior cells display an extended proliferative period and undergo neurogenesis only at tailbud stage. Recent studies have identified several important components of the molecular pathways controlling posterior neurogenesis, but little is known about those controlling the timing and positioning of anterior neurogenesis. We investigate the role of Xrx1, a homeobox gene required for eye and anterior brain development, in the control of proliferation and neurogenesis of the anterior neural plate. Xrx1 is expressed in the entire proliferative region of the anterior neural plate delimited by cells expressing the neuronal determination gene X-ngnr-1, the neurogenic gene X-Delta-1, and the cell cycle inhibitor p27Xic1. Positive and negative signals position Xrx1 expression to this region. Xrx1 is activated by chordin and Hedgehog gene signaling, which induce anterior and proliferative fate, and is repressed by the differentiation-promoting activity of neurogenin and retinoic acid. Xrx1 is required for anterior neural plate proliferation and, when overexpressed, induces proliferation, inhibits X-ngnr-1, X-Delta-1and N-tubulin and counteracts X-ngnr-1- and retinoic acid-mediated differentiation. We find that Xrx1 does not act by increasing lateral inhibition but by inducing the antineurogenic transcriptional repressors Xhairy2 and Zic2, and by repressing p27Xic1. The effects of Xrx1 on proliferation,neurogenesis and gene expression are restricted to the most rostral region of the embryo, implicating this gene as an anterior regulator of neurogenesis.
Conditional inactivation ofTgfbr2in cranial neural crest causes cleft palate and calvaria defects
Authors: Ito Yoshihiro , Yeo Jae Yong , Chytil Anna , Han Jun , Bringas Pablo , Nakajima Akira , Shuler Charles F. , Moses Harold L. , Chai Yang
Published: September 2003

Cleft palate and skull malformations represent some of the most frequent congenital birth defects in the human population. Previous studies have shown that TGFβ signaling regulates the fate of the medial edge epithelium during palatal fusion and postnatal cranial suture closure during skull development. It is not understood, however, what the functional significance of TGFβ signaling is in regulating the fate of cranial neural crest (CNC)cells during craniofacial development. We show that mice with Tgfbr2conditional gene ablation in the CNC have complete cleft secondary palate,calvaria agenesis, and other skull defects with complete phenotype penetrance. Significantly, disruption of the TGFβ signaling does not adversely affect CNC migration. Cleft palate in Tgfbr2 mutant mice results from a cell proliferation defect within the CNC-derived palatal mesenchyme. The midline epithelium of the mutant palatal shelf remains functionally competent to mediate palatal fusion once the palatal shelves are placed in close contact in vitro. Our data suggests that TGFβ IIR plays a crucial, cell-autonomous role in regulating the fate of CNC cells during palatogenesis. During skull development, disruption of TGFβ signaling in the CNC severely impairs cell proliferation in the dura mater, consequently resulting in calvaria agenesis. We provide in vivo evidence that TGFβ signaling within the CNC-derived dura mater provides essential inductive instruction for both the CNC- and mesoderm-derived calvarial bone development. This study demonstrates that TGFβ IIR plays an essential role in the development of the CNC and provides a model for the study of abnormal CNC development.
Jawsfest: new perspectives on neural crest lineages and morphogenesis
Authors: Trainor Paul , Nieto M. Angela
Published: September 2003

The neural crest is a fascinating population of cells that migrate long distances in the developing embryo to generate many different derivatives. It also occupies a central position in the origin and patterning of the vertebrate head, and has generated debates about issues such as cell programming versus plasticity and the role of cell death in early morphogenesis. These aspects of the field were revisited and discussed in a recent meeting organized to honour the retirement of Jim Weston and his contribution to the field
From disease to development to cell biology and back
Authors: González-Gaitán Marcos
Published: September 2003

Nowadays, the focus of developmental studies is shifting away from formal models of developmental pathways that are characterised by flow charts of controlling factors connected by arrows, to mechanistic models that explain developmental processes at the cellular level. Surprisingly, this shift towards a cellular view of developmental biology is occurring simultaneously across a range of model organisms. One consequence of taking such a cell biological view of development is that many model organisms are now becoming good models for studies of human disease and therapy.
Genetic mosaic techniques for studyingDrosophiladevelopment
Authors: Blair Seth S.
Published: September 2003

Genetic screens for recessive mutations continue to provide the basis for much of the modern work on Drosophila developmental genetics. However, many of the mutations isolated in these screens cause embryonic or early larval lethality. Studying the effects of such mutations on later developmental events is still possible, however, using genetic mosaic techniques, which limit losses or gains of genetic function to specific tissues and cells, and to selected stages of development. A variety of genetic mosaic techniques have been developed, and these have led to key insights into developmental processes in the fly. Variations on these techniques can also be used to screen for novel genes that are involved in non-embryonic patterning and growth.
Fluorescence Probe Method for Investigating Polymer Structures in Nanometer Dimensions
Authors: Ito Shinzaburo , Aoki Hiroyuki
Published: September 2003

The applications of the optical methods using fluorescent probes for investigating polymer structure and dynamics at a molecular level are reviewed. The versatile and particular abilities of the fluorescence method have been exemplified using ultrathin films made of polymer monolayers, which provided fine model systems designed with a nanometer precision. In the latter part of this article, the emerging research field of scanning near-field optical microscopy (SNOM) is introduced. This novel microscopic technique enabled us to carry out spectroscopic and time-resolved measurements with a lateral resolution of 100 nm, which is obviously beyond the diffraction limit of light. We applied SNOM to study various nanometer-scale structures of polymer assemblies, such as the two-dimensional phase separation structure, morphology of single polymer chains, and structural inhomogeneity of polymer networks. These results showed that the combination of the fluorescence method and SNOM technique will open a new field of research on polymeric materials by providing molecular information on the basis of real optical images on a nanometric scale.
Transient Thermal Expansion of a Protein in Solution after Photo-Excitation of the Chromophore: Deoxymyoglobin
Authors: Miyata Ryoji , Terazima Masahide
Published: September 2003

The energy releasing process from a photo-excited chromophore embedded in a protein structure to the surrounding protein matrix and to the solvent is studied for deoxymyoglobin by the acoustic peak delay method with the transient grating technique. The acoustic peak delay time is usually a good indicator of the solvent heating time by the nonradiative transition after the photoexcitation and should be a positive value. However, the peak delay after the photoexcitation of deoxymyoglobin was found to be −15 ps. The observed negative peak delay was interpreted in terms of interference between two acoustic waves: an acoustic wave due to the thermal expansion of the protein and a wave of the medium. A theoretical calculation suggests that most of the energy of the heme is first transferred to the protein part and subsequently dissipates into the solvent. During this energy-releasing process, the protein experiences the transient thermal expansion and it creates an acoustic wave.
Theoretical Study of Solvent-Exchange Reactions on Hexasolvated Divalent Cations in the First Transition Series: Model Calculation of a Hydrogen Cyanide Exchange
Authors: Wasada-Tsutsui Yuko , Wasada Hiroaki , Funahashi Shigenobu
Published: September 2003

The stability of divalent cations (M(II)) of the first transition series, penta-, hexa-, and heptasolvated by hydrogen cyanide was studied in order to clarify the reaction mechanisms of nitrile-exchange reactions. The structural stabilities of the [M(NCH)7]2+s depend on the d-electron configurations, though all of the [M(NCH)5]2+s and [M(NCH)6]2+s are located at the local minima. The [M(NCH)7]2+s are structurally more stable than the heptahydrated analogues. Successive binding energies show that it is difficult for an incoming ligand to penetrate the first solvation shells of cations in the later members. Thus, the associative mechanism of solvent-exchange reactions is favorable for cations in the earlier members resulting from energetics as well as structural stability. The symmetry of the imaginary vibrational mode along the reaction path corresponds to that of the transition density induced by one-electron excitation from the antibonding orbital occupied in the d3 ion to the 4s orbital. The stable [M(NCH)7]2+s arise from the large excitation energies sufficient to reduce the second term (see Eq. 4 in the text) of Bader–Pearson’s second-order perturbation expansion.
An NMR Study on the Dynamic Behavior of Triethylamine Included in AFI Crystals — Influence of Acid Sites on the Motional State of Triethylamine Molecules —
Authors: Gotoh Kazuma , Ishimaru Shin’ichi , Ikeda Ryuichi
Published: September 2003

The 1H NMR spin-lattice relaxation times (T1) of triethylamine (TEA) molecules included in five kinds of AFI crystals with different concentrations of Si atoms in the wall were measured. The temperature and Larmor frequency dependences of T1 were well explained by introducing a distributed motional correlation time (τ) for the pseudo-C3 TEA reorientation. An obtained linear decrease in the τ distribution width with an increase of the Si concentration, i.e., the number of Brønsted acid sites, was shown to be related to the orientations of TEA molecules in channels.
Molecular Complex Formation between Riboflavin and Salicylate in an Aqueous Medium
Authors: Datta Silpi , Mukhopadhyay Chaitali , Bose Swapan Kumar
Published: September 2003

Evidence for an intermolecular interaction of riboflavin and sodium salicylate in an aqueous medium was obtained from the presence of isosbestic points in the absorption spectra and an isoemissive point in the emission spectra. The equilibrium constant was estimated from absorption and emission studies, and also from the solubility of riboflavin in an aqueous solution of sodium salicylate, and was found to be in the range of 10–14 mol dm−3. Lifetime measurements indicate a predominantly static mechanism of quenching. The Stern–Volmer constant for the quenching of riboflavin by sodium salicylate was significantly reduced upon the addition of urea. An MD simulation study on the system revealed a stacked conformation, which is probably due to a hydrophobic interaction of the two components.
Hydrogen Atom Position in Hydrated Iodide Anion from X-ray Absorption Near Edge Structure
Authors: Tanida Hajime , Kato Ken-ichi , Watanabe Iwao
Published: September 2003

Hydrogen atom position in the hydrated iodide anion complex is determined from X-ray Absorption Near Edge Structure (XANES) of an aqueous iodide solution at both the K- and L-edges. The spectra are compared with the theoretical ones calculated by using the FEFF method for several model geometries having hydrogen atoms at different positions. Satisfactory agreements are obtained from models with an almost linear alignment of iodine–hydrogen–oxygen atoms, indicating the capability of the XANES analysis when it is combined with the multiple scattering calculations as a method to detect the positions of hydrogen atoms in the first coordination sphere.
Excited-State Dipole Moments of Indoles Using Solvatochromic Shift Methods: An Experimental and Theoretical Study
Authors: Sharma Neera , Jain Sapan K , Rastogi Ramesh C
Published: September 2003

The electronic absorption and fluorescence spectra of some indoles were recorded at room temperature in solvents of different polarities. In order to elucidate the solvent band shifts during relaxation of the excited states, the dipole moments of the excited singlet states were estimated from solvent-dependent Stokes shift data using a solvatochromic method based on a microscopic solvent polarity parameter (ETN). All indoles show a substantial increase in the dipole moment upon excitation to the emitting state. These results are generally consistent with the Austin model 1 (AM1) calculations, and are found to be quite reliable in view of the fact that the correlation of the solvatochromic Stokes shifts with the microscopic solvent polarity parameter (ETN) is superior to that obtained using bulk solvent polarity functions in almost all the systems studied here.
Stopped-Flow Spectroscopic Studies on the Ligand-Exchange Reaction of Cu–(Glycine-Peptide) Complexes, Cu(H−iL), with Cysteine. Cu(II) Transport and Characterization of the Intermediate Ternary Complexes Cu(H−1L)(Cys−); L = Glycylglycine (i = 1), Triglycine (i = 2), Tetraglycine (i = 2 or 3), and Pentaglycine (i = 2 or 3)
Authors: Hanaki Akira , Hiraoka Manabu , Abe Toshikazu , Funahashi Yasuhiro , Odani Akira
Published: September 2003

Cu(II) complexes of glycine-peptides, abbreviated as Cu(H−iL): L = glycylglycine, triglycine, tetraglycine, and pentaglycine (i = 1–3), react with cysteine to form ternary complexes, Cu(H−1L)(Cys−), as first intermediates. The spectral parameters of the ternary complexes, which were similar irrespective of the peptides, were as follows: λmax = 332 ± 1 nm (ε = 4250 ± 50 M−1 cm−1), g|| = 2.170 ± 0.005, g⊥ = 2.00 ± 0.05, and A|| = (2.05 ± 0.01) × 10−4 cm−1, indicating that the ternary complexes have identical coordination structures: the Cu(II) coordinates with the peptides via the nitrogens from the terminal amino and the neighboring deprotonated-amide group, and with cysteine via the amino nitrogen and the thiolate sulfur. Based on the absorbance-time curves, the concentrations of each Cu(II) and Cu(I) species during the reaction were calculated. The species distribution curve clearly visualized the pathway of the Cu(II) transport from Cu(H−iL) to Cu(Cys−)2 via Cu(H−1L)(Cys−). The rate of Cu(H−1L)(Cys−) formation, which was evaluated from the initial increase in the species distribution curve, depended on the coordination modes of the Cu(H−iL) complexes. Both the Cu(H−1L), involving N,N−,O−,O* donors, and the Cu(H−2L), involving N,N−,N−,O−* donors, rapidly formed Cu(H−1L)(Cys−) complexes, where the donors asterisked represent the fourth ligand in the Cu(H−iL) complexes. The second-order rate constant, k1+, was on the order of 106 M−1 s−1, or bigger. The Cu(H−3L), involving N,N−,N−,N−* donors, reacted relatively slowly; k1+ was on the order of 104 M−1 s−1. Those results indicate that the affinity of the Cu(II) for the fourth donor in Cu(H−iL) determines the rate of metal-transport.
Characterization of the Peroxidase Activity of Single Algae Protoplasts by Scanning Electrochemical Microscopy
Authors: Zhou Huafang , Kasai Shigenobu , Noda Hiroyuki , Ohya-Nishiguchi Hiroaki , Shiku Hitoshi , Matsue Tomokazu
Published: September 2003

The peroxidase activity in a single protoplast of alga Bryopsis plumosa is quantitatively characterized by scanning electrochemical microscopy. The generation of ferriceniummethanol (FMA+) at the protoplast surface is directly detected by the microelectrode tip scanned close to the sample surface in seawater containing ferrocenemethanol (FMA) and hydrogen peroxide, an electron mediator and an enzyme-substrate, respectively. The oxidation reaction requires hydrogen peroxide, which clearly shows FMA+ generation due to the peroxidase (POD) catalytic reaction occurring in the protoplast. The FMA+ generation and the FMA accumulation rates at a single alga protoplast were equivalent. A plot of the FMA+ generation rates according to the hydrogen peroxide concentrations was well allowed with a Michaelis–Menten-type reaction. An estimation of the mass-transfer rate and a determination of the Km are quite important advantages of the SECM technique that cannot be realized using other techniques. The POD activity has been further investigated from the viewpoint of the size of the protoplast. The POD activity of the alga in the adult stage is also visualized by SECM. The noninvasive nature of the SECM technique has been confirmed by observing the developmental process after measurements.
Metal-Ion Extractability of Sulfur-Bridged Oligomers of Phenol; Distinct Effect of the Number of Sulfur Bridges Rather Than the Cyclic/Acyclic Form
Authors: Iki Nobuhiko , Morohashi Naoya , Yamane Yusuke , Miyano Sotaro
Published: September 2003

The solvent-extraction behavior of 2,8,14,20-tetrathiacalix[4]arene 2 was compared with those of 2-monothiacalix[4]arene 3 as well as linear tetramer (4) and dimer (5) of p-tert-butylphenol linked by sulfide bonds at the ortho positions in order to clarify the effect of the cyclic and acyclic structure and the number of sulfide bonds. The linear tetramer 4 showed almost the same extraction behavior as that of the cyclic counterpart 2, showing the dependence on the pH for the extraction of Co(II), Ni(II), Cu(II), and Zn(II) ions. On the other hand, monothiacalix[4]arene 3 and acyclic dimer 5 showed far inferior extractability as compared to the former two, suggesting that the number of sulfide linkages, rather than the cyclic/acyclic structure, is predominant to determine the extractability. An equilibrium study on the extraction behavior of open-chain 4 (H4L) toward Co(II), Cu(II), and Zn(II) ions revealed that the composition of the extracted species can be written as [Mi(H2L)i] (i: integer), as was the case obtained by cyclic 2. Furthermore, the extraction constants of 4 for those metal ions were almost the same as those obtained by 2. The similarity of the extraction behavior between 2 and 4 suggests that the acyclic tetramer 4 may act as a pseudo-thiacalix[4]arene to have the same complexation manner as cyclic 2 by the O−,S,O−-donor set, in which the presence of a phenol unit flanked by sulfide bonds at the both ortho positions is essential. In other words, the effect of the bridging sulfide in the phenol oligomers may be reasonably explained by the electron-withdrawing effect of the sulfide moiety to provide the phenol unit with a higher acidity to form [M2(H2L)2]-type complexes having a double-cone structure stabilized by two sets of O−,S,O−-ligated metal bridges.
Macrocyclic Heterodinuclear CoIIMII (M = Ni, Zn) Complexes. Ferromagnetic Interaction and EPR of CoIINiII (SCo = 1/2, SNi = 1) Complex
Authors: Danjobara Kazutoshi , Mitsuka Yuko , Miyasato Yuji , Ohba Masaaki , Okawa Hisashi
Published: September 2003

The dinucleating compartmental ligand (L2,3)2−, derived from the [2:1:1] cyclic condensation of 2,6-diformyl-4-methylphenol, ethylenediamine and 1,3-trimethylenediamine, has formed heterodinuclear CoIIMII complexes, [CoM(L2,3)](ClO4)2·H2O·0.5CH3CN (M = Ni (1), Zn (2)). Crystallographic studies for [CoNi(L2,3)(CH3CN)3](ClO4)2·2MeOH·0.5H2O (1′) indicate that the CoII is bound to the N2O2 site formed with ethylenediamine and has a square-pyramidal geometry with one acetonitrile molecule at the apex. The Ni is bound to the N2O2 site formed with 1,3-trimethylenediamine and has a pseudo octahedral geometry with two acetonitrile molecules at the axial sites. Complex 1 shows a ferromagnetic interaction between the CoII (S = 1/2) and NiII (S = 1) ions and a frozen DMF solution of 1 at liquid nitrogen temperature exhibits EPR signals attributable to the ST = 3/2 ground state with a zero-field splitting of D = 0.095 cm−1. The cryomagnetic property is simulated, based on isotropic model (H = −2JS1S2) and by taking into consideration the zero-field splitting, to give an exchange integral of J = +22 cm−1.
Production and Characterization of Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) from l-Valine by Ralstonia eutropha
Authors: Kimura Hiroshi , Mouri Kiminari , Takeishi Makoto , Endo Takeshi
Published: September 2003

The biosynthesis of polyesters from different l-amino acids was investigated by wild-type Ralstonia eutropha (formerly Alcaligenes eutrophus). The accumulation and degradation of the polyesters was found to occur during the cultivation time from 6 h to 48 h, when R. eutropha was cultivated on nitrogen-poor medium containing 1% (w/v) of each l-amino acid as the sole carbon source by two-step batch fermentation. l-Valine was best among different l-amino acids used for the polyester productivity. The polyester content in dried cells produced from l-valine as the sole carbon source was up to 36 wt % during the cultivation time from 24 h to 36 h in a two-step fermentation and up to 27 wt % during 120 h of culture time in a one-step fermentation, respectively. The compositions and molecular weights of the polyesters produced from l-valine were ca. 90 mol% of 3-hydroxybutyric acid (3HB) and ca. 10 mol% of 3-hydroxyvaleric acid (3HV) units and up to 5 × 105–8 × 105 g mol−1, respectively. As-biosynthesized P(3HB-co-ca. 10 mol% 3HV) was shown to have a random sequence distribution of 3HB and 3HV units by analysis of the 13C NMR spectra and have a very narrow comonomer compositional distribution by the fractionation method with chloroform/heptane mixed solvent.
Photoisomerization and Fluorescence Properties of Hemiindigo Compounds Having Intramolecular Hydrogen Bonding
Authors: Ikegami Masashi , Arai Tatsuo
Published: September 2003

Intramolecularly hydrogen bonded hemiindigo compounds 2–4 were prepared and their photochemical behavior was investigated. Z-2 did not undergo isomerization, while 3 underwent isomerization mutually between the Z-isomer and E-isomer in solution to exhibit a color change between greenish yellow and reddish orange in benzene. Introduction of a formyl group at the 2-position of the pyrrole ring of 3 brought about the increase in the fluorescence quantum yield and fluorescence lifetime by a factor of 10, and the decrease of the quantum yield of isomerization of 4 in benzene. In addition, introduction of the formyl group affects the thermal stability. The intramolecular hydrogen bonding can be used to construct a novel photochromic molecule.
Thermal Rearrangement of 2,5-Bis(dicyanomethylene)bicyclo[4.2.0]oct-7-ene and 2,5-Bis(dicyanomethylene)bicyclo[4.2.0]octa-3,7-diene. Unexpected Formation of 2,6-Bis(dicyanomethylene)bicyclo[3.3.0]octa-1(5)-ene and -octa-3,7-diene, New Electron Acceptors
Authors: Kawase Takeshi , Okada Tomoaki , Enomoto Tetsuya , Kikuchi Takayuki , Miyake Yoji , Oda Masaji
Published: September 2003

Upon heating at 200 °C in o-dichlorobenzene, 2,5-bis(dicyanomethylene)bicyclo[4.2.0]octa-3,7-diene gave rise to 2,6-bis(dicyanomethylene)bicyclo[3.3.0]octa-3,7-diene by a rearrangement as a sole isolable product in modest yield, and no trace of 5,8-bis(dicyanomethylene)cycloocta-1,3,6-triene, the expected product, was detected. On the other hand, 2,5-bis(dicyanomethylene)bicyclo[4.2.0]octa-7-ene underwent a thermal reaction at lower temperature (110 °C in toluene) to give 5,8-bis(dicyanomethylene)-1,3-cyclooctadiene, the normal ring-opened product, and 2,6-bis(dicyanomethylene)bicyclo[3.3.0]octa-1(5)-ene, a rearranged product, in about 1:1 ratio. The rearranged product has a planar 1,1,6,6-tetracyanohexatriene structure (X-ray analysis), and shows a considerably lower electron affinity than that of tetracyanoethylene and 7,7,8,8-tetracyano-p-quinodimethane. The electron acceptor also formed a crystalline 1:1 charge transfer complex with tetrathiafulvalene, of which electronic conductivity was near insulating (1.1 × 10−7 S cm−1). We have proposed a possible mechanism for the rearangements involving the zwitterionic intermediates.
Static and Dynamic Stereochemistry of N-(1,4-Dimethyl-9-triptycyl)hydroxylamine Derivatives
Authors: Yamamoto Gaku , Agawa Chiharu , Ohno Takahiro , Minoura Mao , Mazaki Yasuhiro
Published: September 2003

Static and dynamic stereochemistry of N-alkyl, O-alkyl, and N,O-dialkyl derivatives of N-(1,4-dimethyl-9-triptycyl)hydroxylamine were studied. X-ray crystallographic analysis revealed that an N-alkyl derivative adopts R*-(−sc)* conformation while N,O-dialkyl derivatives adopt R*-ap conformation. In solution, stereomutation was almost frozen on the NMR timescale at ca. −60 °C. The same conformer as found in the crystal was the major conformer in solution in each compound, and a small amount of a second conformer was found in equilibrium with the major one for the N-alkyl and N,O-dialkyl derivatives. The stereomutation was interpreted in terms of diastereomerization and enantiomerization, and the 1H NMR lineshape analysis afforded the activation parameters for these processes.
Practical Resolution of 3-Phenyl-2H-azirine-2-methanol at Very Low Temperature by Using Lipase Immobilized on Porous Ceramic and Optimized Acylating Agent
Authors: Sakai Takashi , Matsuda Akiko , Korenaga Toshinobu , Ema Tadashi
Published: September 2003

A synthetically useful primary alcohol, 3-phenyl-2H-azirine-2-methanol, was resolved efficiently by a reaction at −40 °C with a lipase immobilized on the porous ceramic (Toyonite) and vinyl butanoate in ether (E value of 130 and TTN/h value of 7800).
Indium-Catalyzed Cross-Coupling Reactions between α,β-Unsaturated Carbonyl Compounds and Aromatic Aldehydes
Authors: Ohe Toshiyuki , Ohse Takuya , Mori Kenji , Ohtaka Seiji , Uemura Sakae
Published: September 2003

Cross-coupling reactions between α,β-unsaturated carbonyl compounds and aromatic aldehydes have been achieved in tetrahydrofuran (THF) at 25 °C under N2 using a catalytic amount of InCl3 (0.05 molar amount to the substrate) in the presence of both chlorotrimethylsilane (TMSCl) and aluminum foil (Al). These reactions provide the corresponding β,γ-unsaturated ketones in moderate yields, together with pinacol-coupling products of aldehydes as side products. Chlorides other than TMSCl and AlCl3, such as LiCl, CaCl2, MgCl2, and SOCl2, are not effective at all. Without either TMSCl or Al, no reaction proceeds even in the presence of the catalyst.
Generation of Cycloheptyne during the Solvolysis of Cyclohexylidenemethyliodonium Salt in the Presence of Base
Authors: Fujita Morifumi , Ihara Kenji , Kim Wan Hyeok , Okuyama Tadashi
Published: September 2003

Solvolysis of 4-methylcyclohexylidenemethyl(phenyl)iodonium tetrafluoroborate (1) and its R isomer (69% ee) was carried out in 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoropropan-2-ol (HFP) in the presence of bases such as acetate, pyridine, triethylamine, and alkoxide. The reaction is much faster in TFE than in HFP. Products in TFE include solely un-rearranged (racemized) enol ether 2 together with iodobenzene, while the main product in HFP is ring-expanded (partially racemized) 1-alkoxycycloheptene 3. Results show that 2 is formed via α-elimination with alkylidenecarbene as an intermediate, while the reaction in HFP to give 3 involves a cycloheptyne intermediate that is mostly derived from an intermediate cyclohept-1-enyl cation via the E1-type pathway.
Structure-Activity Relationship of Model Peptides Based on Pleurocidin, an Antibacterial Peptide
Authors: Fukuoka Yumika , Matsushita Yuko , Furukawa Sachi , Niidome Takuro , Hatakeyama Tomomitsu , Aoyagi Haruhiko
Published: September 2003

Pleurocidin (Ple) isolated from the skin of the winter flounder is a cationic amphiphilic peptide with antibacterial activity. To search for a simple peptide with strong antibacterial activity but no hemolytic activity, we designed three model peptides based on Ple, Ple I, Ple II, and Ple III. In the model peptides, Leu or Ala, and Lys were used instead of some hydrophobic amino acids and hydrophilic ones in Ple, respectively, to simplify the amino acid composition. The order of their α-helicity and hydrophobicity is Ple I > Ple II > Ple III. Ple I and Ple II showed antibacterial activity similar to Ple amide (Ple-NH2). However, Ple I had very strong hemolytic activity. Ple III exhibited negligible biological activity. Ple II was found to be a desirable candidate to promote the study of the structure-activity relationship.
Catalytic Friedel–Crafts Acylation of Alkoxybenzenes Mediated by Aluminum Hydrogensulfate in Solution and Solvent-Free Conditions
Authors: Salehi Peyman , Khodaei Mohammad Mehdi , Zolfigol Mohammad Ali , Sirouszadeh Sara
Published: September 2003

Friedel–Crafts acylation of alkoxybenzenes was achieved efficiently by a reaction with aliphatic acid anhydrides in the presence of catalytic amounts of aluminum hydrogensulfate, Al(HSO4)3, in nitromethane and under solvent-free conditions. Alkylbenzenes and aryl halides, as well as aromatic anhydrides, remained intact under these conditions.
Synthesis of Organic–Inorganic Polymer Hybrids Utilizing Amphiphilic Solvent as a Compatibilizer
Authors: Ogoshi Tomoki , Chujo Yoshiki
Published: September 2003

Transparent organic–inorganic polymer hybrids with various organic polymers (polystyrene (PS), poly(methyl methacrylate) (PMMA), poly(vinyl chloride) (PVC) and poly(acrylic acid) (PAA)) that are soluble in amphiphilic solvents such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc), could be easily synthesized by the sol–gel reaction of tetramethoxysilane (TMOS) in an amphiphilic solvent. It is because DMF and DMAc form strong hydrogen bonds with the silanol groups of the silica gel and have a high compatibility with organic polymers. DMF and DMAc play a role as compatibilizers between the organic polymer and silica gel. The hydrogen bonding interaction was confirmed by FT-IR spectra. The compatibility of the organic polymer with the amphiphilic solvent was explained by the solubility of the polymer in an amphiphilic solvent. The thermal stability of the polymer hybrids obtained was increased compared to that of bulk polymer by post-treatment. The homogeneity of the obtained polymer hybrids was confirmed by SEM and nitrogen porosimetry studies.
The Self-assembly, Characterization of Hepatocytes on Nano-sized Gold Colloid and Construction of Cellular Biosensor
Authors: Gu Hai-Ying , Sa Rong-Xiao , Yuan Su-Su , Chen Hong-Yuan , Yu Ai-Min
Published: September 2003

Hepatocytes were successfully assembled on nano-sized gold colloid associated with a cysteamine monolayer on a gold electrode surface to construct a novel cellular biosensor for determining lactate.
Syntheses and Magnetic Properties of Cyclic Tetranuclear and Infinite Linear-chain Copper(II)–Manganese(II) Complexes
Authors: Nakamura Masaaki , Kawachi Minako , Konatsu Chikako , Osa Shutaro , Tarui Takao , Matsumoto Naohide , Re Nazzareno
Published: September 2003

Two heterometal assemblies, [CuIIL2MnII(hfac)] (2) and [CuIIL3MnII(hfac)] (3), have been synthesized by the assembly reaction of “bridging ligand-complex” Na[CuIILn] (n = 2, 3) and [MnII(hfac)2(H2O)2], where H3L2 = 1-(2-hydroxy-3-methoxybenzamido)-2-(2-hydroxybenzylideneamino)ethane, H3L3 = 1-(2-hydroxy-3-methoxybenzamido)-2-(2-hydroxy-3-methoxybenzylideneamino)ethane, and Hhfac = hexafluoroacetylacetone. The temperature-dependent magnetic susceptibility and field-dependent magnetization data demonstrated that 3 was well-reproduced by a cyclic tetranuclear structure, while those of 2 indicated an infinite linear chain structure.
Measurements of Interfacial Complexation of Samarium(III) and its Fluorescence Lifetime by Micro-two-phase Sheath Flow/Fluorescence Microscopy
Authors: Tokimoto Takahira , Tsukahara Satoshi , Watarai Hitoshi
Published: September 2003

The micro-two-phase sheath flow/fluorescence microscopy was used for the fluorescence lifetime measurement for the first time. An inner micro-flow of the toluene solution of samarium(III) complex was flowed in an aqueous phase stream. From the fluorescence decay images observed in the inner flow just after the excitation point, the fluorescence lifetime of the complex was observed. By flowing a toluene solution of ligands into the Sm(III) aqueous stream, the interfacial formation of the fluorescent complex was observed.
New Copper(II) Complexes Connected by NH···O=C and NH···S=C Intermolecular Hydrogen Bonds
Authors: Kondo Mitsuru , Shimizu Emi , Horiba Tomonori , Tanaka Hirokazu , Fuwa Yumiko , Nabari Keiko , Unoura Kei , Naito Tetsuyoshi , Maeda Kenji , Uchida Fumio
Published: September 2003

Two new copper(II) complexes with imidazole-4-carboxylate and imidazole-4-dithiocarboxylate have been synthesized. The monomeric units are connected by NH···O=C and NH···S=C intermolecular hydrogen bonds, respectively, yielding one-dimensional chains that stack with unusually short π–π distances.