bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on adsorption behavior of hemoglobin onto hydrophobic surface by using slab optical waveguide spectroscopy
Authors: Yoshida Takamitsu , Asano Hajime , Santos Jose H. , Qi Zhi‐mei , Takatsu Akiko , Kato Kenji , Matsuda Naoki 
Published: July 2003

AbstractA quartz plate, whose surface was treated with octyltrichlorosilane (OTS), was used as a slab optical waveguide (SOWG) in studying the absorption of hemoglobin by measuring the in situ adsorption spectrum. More hemoglobin is adsorbed on a hydrophobic surface than on a hydrophilic surface. The amount of adsorption increases depending on the time required for surface processing and the solvent concentration. Adsorption of hemoglobin onto the surface did not reach equilibrium even after more than 1 hour. In the case of a hydrophilic surface, the light absorption becomes almost constant within several minutes. The hemoglobin once adsorbed onto the surface persists even if buffered solvent is injected. It is therefore confirmed that hemoglobin is reduced by a reducing solution. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 61–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10125
Measurements of the dielectric properties of nematic liquid crystals at 10 kHz to 40 GHz and application to a variable delay line
Authors: Kamei Toshihisa , Utsumi Yozo , Moritake Hiroshi , Toda Kohji , Suzuki Hirosuke 
Published: July 2003

AbstractIn support of the application of liquid crystals to adaptive devices such as variable delay lines in the microwave and millimeter band, the complex permittivities and response times of five different nematic liquid crystals after voltage application were measured. We measured both the real part $\varepsilon'_{//}$ of the relative permittivity, when the long axis of the liquid crystal molecule is parallel to the high‐frequency electric field, and the relative permittivity $\varepsilon'_{\bot}$ when it is perpendicular to the high‐frequency electric field. The values $\tan\delta_{//}$ and $\tan\delta_{\bot}$ were measured. In the range from 10 kHz to 13 MHz, the capacitance and conductance of a liquid crystal cell sandwiched between ITO glass plates processed by rubbing were directly measured. For 100 MHz to 40 GHz, we propose the new cutback method, in which two coaxial tubes with different lengths are filled with the liquid crystal and the dielectric properties are measured on the basis of their respective group delay and transmission loss. Dielectric relaxation is verified in the low frequency range. In particular, in the range from 3 to 40 GHz, dielectric properties are shown for a continuous change of frequency. It is found that $\varepsilon'_{//}$ and $\varepsilon'_{\bot}$ are kept almost constant regardless of the frequency, taking values of approximately 3 and 2.5, respectively. $\Delta\varepsilon'$, which is the difference between the permittivities in two orientations, exhibits a large variation, from 0.4 to 0.8, depending on the material, which provides crucial data for selecting the optimal material. The response time was measured by placing the liquid crystal cell between two polarizers with the polarizing directions set parallel. The light from a He‐Ne laser (632.8 nm) is directed onto the liquid crystal cell, and the transmitted light is detected by a photodiode. Assuming that the liquid crystal is used in an adaptive device, the speed of operation is investigated. Based on the measurement results for two different nematic liquid crystals, the design of a variable delay line for 20, 30, and 40 GHz is considered, and a principle of liquid crystal material selection is presented. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 49–60, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10130
Proposal and switching characteristics evaluation for waveguide‐prism‐deflector type micro optical switches (WPD‐MOS)
Authors: Ninomiya Minoru , Arai Yukihiko , Yoshimura Tetsuzo , Kurokawa Hiroaki , Asama Kunihiko 
Published: July 2003

AbstractTo handle the drastic increase in communication capacity, the need for large‐scale, high‐speed switching systems is expected. As a solution, we proposed a 3‐Dimensional Micro Optical Switching System (3D‐MOSS) that arranges many thin‐film micro optical switches in multiple layers and connects them with Optical Z‐Connections. This implementation requires a micro optical switch having fast, stable operation. In this paper, we propose a waveguide‐prism‐deflector type micro optical switch (WPD‐MOS) as a candidate 3D‐MOSS thin‐film micro optical switch and analyze its operation. This optical switch forms a prism electrode in a slab waveguide having the electro‐optical effect. The application of voltage produces a dynamic waveguide prism and deflects the optical beam. A feature is the insensitivity of the processing precision to strong temperature fluctuations. An evaluation by the Beam Propagation Method (BPM) demonstrated the ability to implement 2 × 2 micro optical switches having a length of 390 µm, crosstalk ≤ − 12 dB, and insertion losses ≤ 0.96 dB at the drive voltage of 110 V. We also studied a 3 × 3 WPD‐MOS. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 38–48, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10132
On polarization of the Poynting flux
Authors: Tokumaru Shinobu 
Published: July 2003

AbstractThe trajectories of the tips of the electric field vector and the magnetic field vector in real time are explained by the concept of polarization structures. In this paper, the elliptic locus drawn by the tip of the Poynting vector in real time is treated as the ≪polarization≫ structure. From the shape of this polarization, electromagnetic fields can be classified as: $\def\circle#1{{\ooalign{\hfil\raise.07ex\hbox{#1}\hfil\crcr\mathhexbox20D}}} \circle{1}$ characteristic fields (parallel‐polarization similarity fields), $\def\circle#1{{\ooalign{\hfil\raise.07ex\hbox{#1}\hfil\crcr\mathhexbox20D}}} \circle{2}$ plane wave fields (orthogonal‐polarization similarity field), $\def\circle#1{{\ooalign{\hfil\raise.07ex\hbox{#1}\hfil\crcr\mathhexbox20D}}} \circle{3}$ half‐linear polarization fields (either the electric field or the magnetic field is linearly polarized), and $\def\circle#1{{\ooalign{\hfil\raise.07ex\hbox{#1}\hfil\crcr\mathhexbox20D}}} \circle{4}$ other general electric fields. It can be shown that information on the electric and magnetic fields of the primary quantities can be obtained from secondary quantities related to the power of the electromagnetic field. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 28–37, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10139
Periodic‐structure‐type electromagnetic wave absorber analysis by the Non‐Standard FDTD method using complex formulation
Authors: Ohtani Tadao , Kashiwa Tatsuya 
Published: July 2003

AbstractIn this paper, in order to analyze a periodic‐structure electromagnetic wave absorber by the Non‐Standard FDTD (NS‐FDTD) method, an NS‐FDTD method using complex formulation is proposed. In order to clarify the characteristics of this method, the numerical dispersion equation and the stability condition are newly derived. It is found that the proposed NS‐FDTD method using complex formulation is much more accurate and stable than the conventional FDTD method. The present method is also applied to the analysis of a fin ferrite electromagnetic wave absorber with a periodic structure. It is demonstrated that the proposed NS‐FDTD method using complex formulation is an effective method of analysis with higher accuracy than the conventional FDTD method. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 20–27, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10145
Waveguide bandpass filter and FDTD analysis
Authors: Harada Shinnya , Iida Yukio 
Published: July 2003

AbstractIn regard to the FDTD analysis of a waveguide bandpass filter, a method of processing time series FDTD data for the Fourier transform is discussed in conjunction with boundary processing near conductor corners, and a new method of processing the FDTD data is proposed. When this method is used, the total computation time for all FDTD processing is reduced by more than 60%. By a calculation for the iris‐coupled waveguide bandpass filter, it is confirmed that the new grid arrangement method is as accurate as the corner correction method and is more accurate than the conventional grid arrangement method. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 12–19, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10147
Multitone curve‐fitting algorithms for communication application ADC testing
Authors: Motoki Yoshito , Sugawara Hidetake , Kobayashi Haruo , Komuro Takanori , Sakayori Hiroshi 
Published: July 2003

AbstractThis paper describes multitone curve‐fitting algorithms for accurate determination of intermodulation distortion products in the multitone testing of ADCs used in communication applications and the like. Accuracy of our curve‐fitting algorithms for coherent sampling (input frequencies known) and incoherent sampling (input frequencies unknown) was validated by numerical simulations. We found that—especially for incoherent sampling—these algorithms provide better accuracy than conventional (single‐tone) curve‐fitting algorithms. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(8): 1–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10148
Bis(oxazoline)titanium Complexes as Chiral Catalysts for Enantioselective Hydrosilylation of Ketones − A Combined Experimental and Theoretical Investigation
Authors: Bandini Marco , Bernardi Fernando , Bottoni Andrea , Cozzi Pier Giorgio , Miscione Gian Pietro , Umani‐Ronchi Achille 
Published: July 2003

AbstractA combined experimental and theoretical investigation has been carried out on a new catalytic system, based on bis(oxazoline) (BOX) complexes of titanium. These catalytic species are able to reduce aromatic ketones with good enantiomeric excesses and satisfactory yields. The experimental and the computational (DFT) evidence has provided useful information on the nature of the active catalytic species and on the mechanism of the reaction. The most likely reaction path involves a TiIV catalytic species. This result agrees with experimentally obtained evidence that seems to rule out the presence of TiIII species. The analysis of the structure of the transition state corresponding to the reduction process (the addition of the hydride to the carbonyl system), provides an interesting insight on the enantioselectivity that characterizes this reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Biosynthesis of Defensive Compounds from Beetles and Ants
Authors: Laurent Pascal , Braekman Jean‐Claude , Daloze Désiré , Pasteels Jacques 
Published: July 2003

AbstractMany beetle and ant species owe their protection against predators to the presence of defensive compounds in their hemolymph or in specialized exocrine glands. A growing number of studies devoted to the elucidation of the biosynthetic pathways used by the insects to produce these compounds have been reported in recent years. An overview of these studies is presented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of New Thiophene‐Substituted 3,3‐Diphenyl‐3H‐naphtho[2,1‐b]pyrans by Cross‐Coupling Reactions, Precursors of Photomodulated Materials
Authors: Frigoli Michel , Moustrou Corinne , Samat André , Guglielmetti Robert 
Published: July 2003

Abstract3,3‐Diphenyl‐3H‐naphtho[2,1‐b]pyrans linked to one, two, or three thiophene nuclei in different positions of the naphthalene moiety (5, 6, 8, and 9) by a covalent bond have been prepared in good yields. A Suzuki cross‐coupling reaction was used with two possible strategies: chromenization before the coupling with oligothiophenes or chromenization after the coupling, the main intermediates being the diphenyl propargylic alcohol, the functionalized naphthol derivatives, and the thiophenic boronates. The overall yields for obtaining such photochromic compounds are generally quite satisfying. For the 7‐position, the coupling reaction has been realized using a Grignard reaction between a tetralone derivative and a thiophenic bromo magnesium intermediate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Palladium‐Catalyzed Annulation of Aryl‐1,2‐diols and Propargylic Carbonates. Theoretical Study of the Observed Regioselectivities
Authors: Labrosse Jean‐Robert , Lhoste Paul , Delbecq Françoise , Sinou Denis 
Published: July 2003

AbstractMethyl 1‐methylprop‐2‐ynyl carbonate reacts with 3‐ and 4‐substituted benzene‐1,2‐diols to give 2,3‐dihydro‐3‐methyl‐2‐methylidene‐1,4‐benzodioxines, as a mixture of regioisomers in the case of methoxy‐substituted diphenol, and a single regioisomer for the nitro‐ and the formyl‐substituted diphenols. The oxyanion which attacks first corresponds to the less acidic hydroxy function, and the attack of the second oxyanion on the η3‐allylpalladium intermediate is directed toward the more substituted carbon atom. In order to explain the regioselectivity of the cyclization, a theoretical study based on density functional theory (DFT) has been performed. The first step implies an equilibrium between the two oxyanions. The regioselectivity of the second step is due to a subtle balance between the nature of the phosphane, the bulkiness, and the electronic properties of the substituents. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Ring Size seco‐Analogs of the Antitumor Antibiotic CC‐1065 by Two Consecutive Transition Metal‐Initiated Transformations
Authors: Tietze Lutz F. , Looft Jan , Feuerstein Tim 
Published: July 2003

AbstractNovel seco‐analogs of CC‐1065 1 were synthesized from comercially available nitroaniline by reduction, bromination, bisulfonation and bisallylation followed by reaction with tert‐butyllithium, zirconocene and iodine. The obtained quinoline 6 was then transformed into 17 and 18, which, upon treatment with Pd0, led to 21 and 22, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New Functional Hexahelicenes − Synthesis, Chiroptical Properties, X‐ray Crystal Structures, and Comparative Data Bank Analysis of Hexahelicenes
Authors: Wachsmann Claudia , Weber Edwin , Czugler Mátyás , Seichter Wilhelm 
Published: July 2003

AbstractSeven new hexahelicenes (3−7, 9, 10) containing different functional group substituents have been synthesized and, in three cases (4, 8, 10), optically resolved. Optical rotations were measured and CD spectra are reported. X‐ray crystal structures of the helicenes 1, 3, 4, 8, and 9 have been determined, of which 4 represents a 1:1 clathrate with acetone. These show a concerted interplay of C−H···O, C−H···π, and π···π supramolecular interactions in the packings, mostly yielding stacks of molecules (1, 3, 4, 8). Statistical analysis of the molecular dimensions in these and related crystal structures was carried out in order to identify potential parameters relevant to macroscopic phenomena, including optical rotation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Stereoselective Synthesis of (−)‐Deacetylanisomycin
Authors: Merino Pedro , Franco Santiago , Lafuente Diego , Merchan Francisco , Revuelta Julia , Tejero Tomas 
Published: July 2003

AbstractA stereoselective synthesis of (−)‐deacetylanisomycin has been achieved from a nitrone derived from L‐threose in 6 steps and 53.7% overall yield. The key step of the synthesis is the nucleophilic addition of a Grignard derivative with complete diastereofacial selectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Highly Enantioselective Allylation of Arylaldehydes Catalyzed by a Silver(I)‐Chiral Binaphthylthiophosphoramide
Authors: Wang Chun‐Jiang , Shi Min 
Published: July 2003

AbstractChiral diphenylthiophosphoramideL2prepared from diphenylthiophosphinic chloride and (R)‐(+)‐N‐ethyl‐1,1′‐binaphthyl‐2,2′‐diamine2was used as a catalytic chiral ligand in the silver(I)‐catalyzed enantioselective allylation reaction of arylaldehydes with allyltributyltin to furnish highee(up to 98%) of the homoallylic alcohols. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Highly Selective Negishi Cross‐Coupling Reaction of a Zinc‐Metallated Ferrocenyl p‐Tolyl Sulfoxide: New Chiral Ferrocene‐Based Quinone Ligands
Authors: Cotton Hanna K. , Huerta Fernando F. , Bäckvall Jan‐E. 
Published: July 2003

AbstractA highly selective Negishi coupling of zinc‐metallated ferrocenyl p‐tolyl sulfoxide with aryl bromides was developed. With Pd(PPh3)4 as catalyst, a well‐matched system in terms of reactivity of organometallic compound, aryl bromide, and catalyst, was obtained. The scope of the reaction was studied by the use of aryl bromides 7a−g, which afforded high yields of coupling products. The reaction conditions for the preparation of ferrocenyl p‐tolyl sulfoxide, according to the Andersen method, were optimised to give a yield of 80% and an enantiomeric excess of 98%. Target compound 1b was obtained by deprotection of acetate‐protected hydroquinone 8f, employing sodium borohydride in dimethoxyethane, in a yield of 87%. Target compounds 2b and 3b decomposed during workup. The possibility of internal electron transfer, between the ferrocene moiety and the hydroquinone moiety, may account for this instability. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Tetraphenylethene‐Derived Columnar Liquid Crystals and Their Oxidative Photocyclization
Authors: Schultz Andreas , Laschat Sabine , Diele Siegmar , Nimtz Manfred 
Published: July 2003

AbstractThe synthesis of novel tetraphenylethenes 9a−f, 13, and 18a,b bearing ether, biphenyl, and 4‐cyanobiphenyl moieties via a McMurry reaction and Suzuki coupling as key steps is described. Mesogenic properties of these compounds were studied by differential scanning calorimetry (DSC), optical polarizing microscopy, and X‐ray diffraction. Ether‐substituted derivatives 9a,b with chain lengths C8 or C9 were non‐mesogenic. Compounds 9c−f with longer alkyl chains displayed hexagonal columnar mesophases. Whereas cyanobiphenyl derivative 13 was non‐mesogenic, the corresponding biphenyl systems 18a,b with decyloxy and dodecyloxy chains, respectively, formed hexagonal columnar mesophases. Oxidative photocyclization of compounds 1f, 9c, 13, and 18a were investigated. Upon irradiation in the presence of iodine tetraphenylethenes 1f, 9c gave the corresponding phenanthrenes 22a,b. The mesomorphic properties of 22a,b were strongly dependent on the substituent. Whereas ether 22a displayed only isotropic melting, a hexagonal columnar mesophase was found for ester 22b. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
[2+2+2] Cocyclotrimerization with Ferrocenylalkynes
Authors: Dufková Lenka , Císařová Ivana , Štepnička Petr , Kotora Martin 
Published: July 2003

AbstractCocyclotrimerization of ferrocenylalkynes FcC≡CR (R = H and CH2OH) with α,ψ‐diynes X(CH2C≡CH)2, where X = O, C(CO2Et), C(CN)(CO2Et), C(COMe)2, and C(COMe)(CO2Et), to give functionalised ferrocenylarenes was attempted in the presence of various catalytic systems: [RhCl(PPh3)3], [CoBr(PPh3)3], [NiBr2(dppe)]/Zn, [{Ir(cod)Cl}2]/dppe and [CpCo(cod)]/PPh3 [Cp = η5‐cyclopentadienyl, cod = η4‐cycloocta‐1,5‐diene, and dppe = 1,2‐bis(diphenylphosphanyl)ethane]. The results indicate that Wilkinson’s catalyst effects the cocyclotrimerization to afford the respective ferrocenylarenes in good yields and under mild conditions regardless of the nature of the functional groups. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
endo/exo Preferences for Double Bonds in Three‐Membered Rings Including Phosphorus Compounds
Authors: Goumans T. P. M. , Ehlers Andreas W. , Lammertsma Koop , Würthwein Ernst‐Ulrich 
Published: July 2003

AbstractDepending on the substituent and the heteroelements of an unsaturated three‐membered ring system of the methylenecyclopropane/1‐methylcyclopropene type, the double bond may be preferentially exo‐ or endocyclic. This preference may be considered as a combination of substituent and ring‐strain effects. The substituent effect is a composite one, encompassing both exocyclic olefinic strain and tautomeric preference. The preference for exocyclic unsaturation increases in the order =CH2 < =NH < =PH < =O for the considered substituents. The higher the ring‐strain, the higher the propensity for exocyclic unsaturation. The low‐strain 2H‐phosphirenes favor endocyclic unsaturation, except for the 3‐OH‐substituted species where the strong C=O double bond is the determining factor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Preparation and Characterization of Sulfonyl‐Azafulleroid and Sulfonylaziridino‐Fullerene Derivatives
Authors: Ulmer Lars , Mattay Jochen 
Published: July 2003

AbstractThermolysis of several sulfonyl azides in the presence of C60 leads either to aza[60]fulleroids or to mixtures of aza[60]fulleroids and corresponding aziridino‐fullerenes, depending on the substituent at the sulfonyl group. In all cases, 1,2‐closed aziridino‐fullerenes can be obtained from azafulleroids by irradiation. Addition of sulfonyl azides to C70 only yields azafulleroids with Cs‐symmetry. Cyclic‐voltammetric measurements revealed that there is no significant change of electrochemical properties compared to C60 and C70. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Flexible Synthesis of Indoline, Indolizidine, and Pyrrolizidine Derivatives
Authors: Bytschkov Igor , Siebeneicher Holger , Doye Sven 
Published: July 2003

AbstractNew and flexible procedures for the synthesis of indoline, indolizidine, and pyrrolizidine derivatives are described. By these new procedures, the target compounds can be synthesized with high diversity from three building blocks (ortho‐bromo‐ or ortho‐chloro‐iodobenzenes, terminal alkynes, and primary amines). The synthetic strategies presented include Sonogashira couplings, Cp2TiMe2‐catalyzed hydroaminations of alkynes, and Pd‐catalyzed aminations of aryl halides as key steps. Since many of the employed starting materials are commercially available or easily accessible, a huge number of indoline, indolizidine, and pyrrolizidine derivatives is theoretically obtainable by the standard reaction sequences developed. Since the experimental procedures are simple and mostly catalytic, applications of the described methods for automated synthesis are also imaginable. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
First Synthesis of (8‐2H3)‐(all‐rac)‐δ‐Tocopherol
Authors: Mazzini Francesco , Alpi Emanuele , Salvadori Piero , Netscher Thomas 
Published: July 2003

AbstractTrideuterated tocopherols were needed to be used as internal standards for our study about simultaneous quantitative determination of tocopherols in foodstuffs by mass spectrometry. Whilst procedures for trideuterated α‐tocopherol have been recently optimized, no method is reported as regards δ‐tocopherol. Different synthetic approaches are discussed, as well as the first procedure for the synthesis of (8‐2H3)‐(all‐rac)‐δ‐tocopherol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)