bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tube feet of sea urchins and sea stars contain functionally different mutable collagenous tissues
Authors: Santos Romana , Haesaerts Delphine , Jangoux Michel , Flammang Patrick 
Published: June 2005

SUMMARYEchinoderms possess mutable collagenous tissues (MCTs), which are capable of undergoing rapid changes in their passive mechanical properties mediated by secretions from a specific cell type, the juxtaligamental cell. In this study,the possible presence of MCTs in the tube feet of the echinoid Paracentrotus lividus and the asteroid Marthasterias glacialis was investigated by measuring their extensibility, tensile strength, stiffness and toughness after different treatments known to influence the physiological state of MCTs. Calcium removal reversibly induced a significant plasticization of the tube feet of both species. When exposed to cell-disrupting solutions, the tube foot stem of sea urchins and sea stars showed a significant increase in strength, stiffness and toughness in the absence of calcium. This response, combined with the ultrastructural observation of juxtaligamental-like cells in the connective tissue, confirms that an MCT is present in both echinoid and asteroid tube feet. It was observed, however, that the tube foot stems of P. lividus and M. glacialis are affected differently by exposure to cell-disrupting solutions in the presence of calcium, indicating that their MCTs could be functionally different. In their soft state, MCTs could assist the muscles in tube foot protraction, bending and retraction; in their stiff state, they could play a role in the energy-sparing maintenance of position; for example,during strong attachment to the substratum to resist hydrodynamically generated loads.
The mechanical scaling of coasting in zebrafish (Danio rerio)
Authors: McHenry Matthew J. , Lauder George V. 
Published: June 2005

SUMMARYMany fish species span two or three orders of magnitude in length during the growth from larvae to adults, and this change may have dramatic consequences for locomotor performance. We measured how the performance of coasting changes over the life history of zebrafish (Danio rerio) and examined the scaling of mechanics underlying this change. Adult zebrafish coast disproportionately further and faster and maintain their speed for a longer duration than do larvae and juveniles. Measurements of drag on tethered dead fish suggest that adult fish operate in an inertial regime by coasting at relatively high Reynolds numbers (Re&gt;1000), and in vivodrag measurements showed adults to operate with a drag coefficient(Cinert≈0.024) that was consistent with previously published estimates. However, drag scaled differently at lower Revalues than those assumed in previous studies. We found a viscous regime at Re&lt;300, which corresponds to the routine coasting of larvae and juveniles. Despite these changes in hydrodynamics over growth, a mathematical model of coasting mechanics suggests that the disproportionately longer coasting of adults is caused primarily by their large body mass and high speed at the beginning of coasting. We therefore propose that changes in coasting performance with growth are dictated primarily by the scaling of momentum rather than resulting from hydrodynamic changes. These results provide an opportunity for new interpretations of function in the growth and evolution of fish.
Adaptations to an extreme environment: retinal organisation and spectral properties of photoreceptors in Antarctic notothenioid fish
Authors: Pointer Marie A. , Cheng Chi-Hing Christina , Bowmaker James K. , Parry Juliet W. L. , Soto Nelyn , Jeffery Glen , Cowing Jill A. , Hunt David M. 
Published: June 2005

SUMMARYThe Notothenioid suborder of teleosts comprises a number of species that live below the sea ice of the Antarctic. The presence of `antifreeze'glycoproteins in these fish as an adaptation to freezing temperature has been well documented but little is known about the adaptations of the visual system of these fish to a light environment in which both the quantity and spectral composition of downwelling sunlight has been reduced by passage through ice and snow. In this study, we show that the red/long-wave sensitive (LWS) opsin gene is not present in these fish but a UV-sensitive short-wave sensitive(SWS1) pigment is expressed along with blue-sensitive (SWS2) and green/middle-wave sensitive (Rh2) pigments. The identity and spectral location of maximal absorbance of the SWS1 and Rh2 pigments was confirmed by in vitro expression of the recombinant opsins followed by regeneration with 11-cis retinal. Only the SWS2 pigment showed interspecific variations in peak absorbance. Expression of the Rh2 opsin is localised to double cone receptors in both the central and peripheral retina, whereas SWS2 opsin expression is present only in the peripheral retina. SWS1 cones could not be identified by either microspectrophotometry or in situ hybridisation,presumably reflecting their low number and/or uneven distribution across the retina. A study of photoreceptor organisation in the retina of two species,the shallower dwelling Trematomus hansoni and the deeper dwelling Dissostichus mawsoni, identified a square mosaic in the former, and a row mosaic in the latter species; the row mosaic in Dissostichus mawsoni with less tightly packed cone photoreceptors allows for a higher rod photoreceptor density.
Digestive state influences the heart rate hysteresis and rates of heat exchange in the varanid lizardVaranus rosenbergi
Authors: Clark T. D. , Butler P. J. , Frappell P. B. 
Published: June 2005

SUMMARYTo maximize the period where body temperature (Tb)exceeds ambient temperature (Ta), many reptiles have been reported to regulate heart rate (fh) and peripheral blood flow so that the rate of heat gain in a warming environment occurs more rapidly than the rate of heat loss in a cooling environment. It may be hypothesized that the rate of cooling, particularly at relatively cool Tbs, would be further reduced during postprandial periods when specific dynamic action (SDA) increases endogenous heat production (i.e. the heat increment of feeding). Furthermore, it may also be hypothesized that the increased perfusion of the gastrointestinal organs that occurs during digestion may limit peripheral blood flow and thus compromise the rate of heating. Finally, if the changes in fh are solely for the purpose of thermoregulation, there should be no associated changes in energy demand and, consequently, no hysteresis in the rate of oxygen consumption(V̇O2). To test these hypotheses, seven individual Varanus rosenbergi were heated and cooled between 19°C and 35°C following at least 8 days fasting and then approximately 25 h after consumption of a meal (mean 10% of fasted body mass). For a given Tb between the range of 19-35°C, fh of fasting lizards was higher during heating than during cooling. Postprandial lizards also displayed a hysteresis in fh, although the magnitude was reduced in comparison with that of fasting lizards as a result of a higher fh during cooling in postprandial animals. Both for fasting and postprandial lizards,there was no hysteresis in V̇O2 at any Tb throughout the range although, as a result of SDA,postprandial animals displayed a significantly higher V̇O2 than fasting animals both during heating and during cooling at Tbs above 24°C. The values of fh during heating at a given Tb were the same for fasting and postprandial animals,which, in combination with a slower rate of heating in postprandial animals,suggests that a prioritization of blood flow to the gastrointestinal organs during digestion is occurring at the expense of higher rates of heating. Additionally, postprandial lizards took longer to cool at Tbs below 23°C, suggesting that the endogenous heat produced during digestion temporarily enhances thermoregulatory ability at lower temperatures, which would presumably assist V. rosenbergiduring cooler periods in the natural environment by augmenting temperature-dependent physiological processes.
Formation of Selective Adsorption Cavity by Chemical Vapor Deposition of Molecular Sieving Silica Overlayer on Alumina using Molecular Template in the Presence of Acetic Acid
Authors: Katada Naonobu , Akazawa Sachiko , Nishiaki Noriko , Yano Yuiko , Yamakita Shohei , Hayashi Kentaro , Niwa Miki 
Published: June 2005

Abstract
Chemical vapor deposition (CVD) of tetramethoxysilane was carried out on alumina after the pre-adsorption of aldehyde as the molecular template, in order to form a molecular-sieving silica overlayer with controlled cavities. The adsorption of a molecule (1-naphthaldehyde) larger than the template was almost completely suppressed when acetic acid was added during CVD, showing a high selectivity based upon the shapes of the controlled cavity and the adsorbed molecule, while the selectivity was low when acetic acid was not used. The infrared (IR) spectrum and nuclear magnetic resonance (NMR) of 29Si showed that the acetic acid enhanced the oligomerization of Si alkoxide via hydrolysis, probably by acid catalysis, resulting in the formation of a dense network of siloxane. Such a dense wall of silica is speculated to determine the shape of the adsorption cavity precisely, and to generate high selectivity.
Syntheses of [60]Fullerene and N,N-Bis(4-biphenyl)aniline-Tethered Rotaxane: Photoinduced Electron-Transfer Processes via Singlet and Triplet States of [60]Fullerene
Authors: Sandanayaka Atula S D , Ikeshita Kei-ichiro , Watanabe Nobuhiro , Araki Yasuyuki , Furusho Yoshio , Kihara Nobuhiro , Takata Toshikazu , Ito Osamu 
Published: June 2005

Abstract
A rotaxane containing [60]fullerene (C60) and N,N-bis(4-biphenyl)aniline (BBA) moieties was synthesized. In this structure, C60 acting as an electron acceptor, is attached to the crown-ether ring through which the axle with terminal BBA moieties acting as electron donors on both ends is penetrating. This rotaxane had a neutral amide moiety in the center of the axle in which two BBA moieties act as stoppers. The intra-rotaxane photoinduced electron-transfer processes of the C60 and BBA moieties were investigated by time-resolved transient absorption and fluorescence measurements while changing solvent polarity and temperature. Time-resolved transient absorption measurements of the rotaxanes confirmed that the long-lived charge-separated state (C60•−; BBA•+)rotaxane was formed via both the excited singlet and triplet states of C60 (1C60* and 3C60*, respectively) in polar solvents. The rate constants for charge-separation process were evaluated to be in the range of (3.6–3.7) × 108 s−1 via 1C60* and (5.1–5.6) × 107 s−1 via 3C60* in the ratio of (0.36–0.38):(0.43–0.51). The rate constants of charge recombination were 2.5 × 106 s−1 and 4.4 × 106 s−1, corresponding to the lifetimes of the charge-separated states of 400 ns and 230 ns in THF and benzonitrile, respectively. By the temperature dependences, the activation free-energy changes of charge-separation process via 3C60* were evaluated to be 0.10 eV, while those of the charge-recombination process were estimated to be 0.03 eV in THF and benzonitrile. These low activation energies are one of the characteristics of through-space electron transfer in the rotaxanes.
Characteristics of a Hydrogen Concentration Cell Constituted with a Redox Pair of 2-Propanol Dehydrogenation and Acetone Hydrogenation
Authors: Ando Yuji , Sasaki Tomokazu , Yatabe Yuka , Saito Yasukazu , Tanaka Tadayoshi 
Published: June 2005

Abstract
A hydrogen concentration cell, constituted with a redox pair of 2-propanol dehydrogenation and acetone hydrogenation on electrode catalysts, has been studied, with which low-quality waste heat below 100 °C can be converted into electric power. The magnitudes of the open-circuit voltage (VOC) of this cell were found to be dependent on the anode abilities concerned with C–H bond splitting and hydrogen spillover. The kinetical spillover capabilities of carbon-supported Pd-based composite metal catalysts were obtained separately and compared with the magnitudes of VOC, whereas the catalytic dehydrogenation activities for 2-propanol were more closely related with the magnitudes of a short-circuit current (ISC).
Syntheses, Crystal Structure, and Magnetic Properties of Mn12 Single-Molecule Magnets with Naphthalenecarboxylate Bridges, [Mn12O12(O2CC10H7)16(H2O)4] and Their Tetraphenylphosphonium Salts
Authors: Bian Guo-Qing , Kuroda-Sowa Takayoshi , Nogami Tadahiro , Sugimoto Kunihisa , Maekawa Masahiko , Munakata Megumu , Miyasaka Hitoshi , Yamashita Masahiro 
Published: June 2005

Abstract
The preparation and physical characterization are reported for three Mn12 single-molecule magnets (SMMs) having naphthalenecarboxylate bridges, [Mn12O12(2-nc)16(H2O)4] (1, 2-ncH = 2-naphthalenecarboxylic acid), its Ph4P+ salt (2) and [Mn12O12(1-nc)16(H2O)4] (3, 1-ncH = 1-naphthalenecarboxylic acid). Complex 1·2CH2Cl2·4.5H2O crystallizes in the monoclinic space group C2/c, with cell dimensions at −160 °C of a = 28.524 Å, b = 17.819 Å, c = 36.058 Å, β = 92.399°, and Z = 4. The X-ray structure analysis of 1·2CH2Cl2·4.5H2O reveals that each [Mn12] molecule is connected to the neighboring molecules through eight π···π interactions to form a two-dimensional structure within the bc-plane. This is the first SMM that self-assembles two-dimensionally via π···π interaction. From Arrhenius plots of the frequency dependence of the temperatures of the χ″M peaks, the effective energy barriers Ueff for the reversal of the magnetization spin were estimated to be 61 K, 53 K, and 61 K for high-temperature phases of 1–3, respectively, and 31 K and 33 K for the low-temperature (LT) phases of 1 and 3, respectively. The analysis of the reduced magnetization data suggests that the LT phase of 1 has an S = 9 ground state with g = 1.998 and D = −0.61 K.
Syntheses, Structures, Spectroscopic Properties, and Thermal Behavior of Nickel(II) Mixed-Ligand Complexes with N,N,N′,N′-Tetramethylethylenediamine, Benzoylacetonate, and a Halide Anion
Authors: Miyamoto Keiko , Sakamoto Mariko , Tanaka Chikashi , Horn Ernst , Fukuda Yutaka 
Published: June 2005

Abstract
A series of nickel(II) complexes comprising N,N,N′,N′-tetramethylethylenediamine (tmen), benzoylacetonate (bzac), and a halide anion (X), Ni(tmen)(bzac)X·n(H2O)(n = 1–4, X = Cl, Br, I), have been synthesized. A crystallographic study revealed that the chloride anion coordinates to the central metal, while bromide and iodide anions are located in the outer coordination sphere as the counter anion; the metal has a slightly distorted octahedral geometry, and the two monodentate ligands (aqua and chloro) are in the cis-position. In bromide and iodide complexes, having two water molecules of crystallization, a ladder-like hydrogen bond network is formed among halide anions, aqua ligands, and water of crystallization. In a chloride complex having no water of crystallization, a dimer is formed by strong intermolecular hydrogen bonding between the aqua ligand and the chloro and the benzoylacetonate ligands of the neighboring molecule. The behaviors of the complexes in solution vary, depending on the nature of the solvents, including deaquation and disproportionation, causing contrasting color changes of the solutions. The presence of a proposed intermediate in the disproportionation reaction, namely a 5-coordinated complex, was confirmed. Thermal gravimetric analysis suggests that these complexes lose water of crystallization, undergo deaquation–anation, and then lose the coordinated water before disproportionation into two ternary complexes.
Antidiabetic Activity of Zn(II) Complexes with a Derivative of l-Glutamine
Authors: Matsumoto Kinuyo , Yamamoto Shuhei , Yoshikawa Yutaka , Doe Matsumi , Kojima Yoshitane , Sakurai Hiromu , Hashimoto Hiroko , Kajiwara Naemi M 
Published: June 2005

Abstract
The insulinomimetic activity of zinc(II) complexes Zn(gln-m)2 and Zn(gln-e)2, respectively, with l-γ-glutamyl-methylamide (gln-m) and -ethylamide (theanine: gln-e), components of green tea, were compared to that of Zn(gln)2 with l-glutamine (gln) in an in vitro study using isolated rodent adipocytes treated with epinephrine in the presence of glucose, expressed as the IC50 value (50% inhibition concentration) of free fatty acids (FFA) released from fat cells. The former were found to have higher inslinomimetic activity than that of the latter. The IC50 values of the former were 0.61 and 0.56, respectively. Then, the anti-diabetic activity of a zinc(II) complex, Zn(gln-e)2, was examined in an in vivo experiment on KK-Ay mice, model animals of type-2 DM, by the intraperitoneal (ip) injection of 3–4 mg Zn/kg b.w./day for 13 days. The blood-glucose level of a group treated with a Zn complex, Zn(gln-e)2, decreased significantly after 13 days compared to those of non-treated and gln-e treated groups. The serum concentrations of triglyceride (TG) and HbA1c decreased significantly in Zn(gln-e)2 treated KK-Ay mice compared to those of the gln-e treated group, respectively. Furthermore, the improvement in glucose tolerance was confirmed by an oral glucose tolerance test.
Preparation and Properties of Fluorenylidene(phenyl)phosphines Bearing Bulky Groups with Electron-Donating Substituents in the Ortho Position on the Phenyl Group
Authors: Kawasaki Subaru , Fujita Takuma , Toyota Kozo , Yoshifuji Masaaki 
Published: June 2005

Abstract
Fluorenylidene(phenyl)phosphines having bulky substituents with an electron-donating group in the o-position on the phenyl group were prepared and their properties were compared. The prepared materials included 2,4-di-t-butyl-6-methoxyphenyl, 2,4-di-t-butyl-6-(phenoxymethyl)phenyl, 2,4-di-t-butyl-6-(dimethylamino)phenyl, or 2,4-di-t-butyl-6-(2-phenylethyl)phenyl. The diphosphenes and dithioxophosphoranes bearing the 2,4-di-t-butyl-6-(phenoxymethyl)phenyl group that formed were observed by 31P NMR spectroscopy; the effects of the substituent on these multiply bonded phosphorus species are discussed.
Syntheses of Glucose-Containing Lipid A Analogues and Their LPS-Antagonistic Activities
Authors: Shiozaki Masao , Doi Hiromi , Tanaka Daisuke , Shimozato Takaichi , Kurakata Shin-ichi 
Published: June 2005

Abstract
Three anomeric pairs of lipid A-type disaccharides containing a glucose on their reducing end were synthesized, and their LPS-antagonistic activities were measured. The inhibitory activities (IC50) on the LPS-induced TNFα production of these six compounds (16α, 16β, 28α, 28β, 40α, and 40β) toward human whole blood cells were 0.35, 0.42, 2.37, 1.16, 2.89, and 7.70 nM, respectively.
Creation of Concave-Shaped Conformation in Crystal Structures Using an Iminodicarbonyl Linker. An Application to Solid-State Intramolecular [4 + 4] Photocycloaddition Reactions of 2-Pyridone Derivatives
Authors: Masu Hyuma , Ohmori Ken , Kishikawa Keiki , Yamamoto Makoto , Yamaguchi Kentaro , Kohmoto Shigeo 
Published: June 2005

Abstract
Single-crystal X-ray structures of 6 carboxamides possessing two units of 2-pyridone moieties connected with an iminodicarbonyl linker were examined to show the usefulness of this linker for the creation of concave-shaped conformation in crystal structures. In all cases, the carboxamides showed concave-shaped conformations in which two 2-pyridone moieties faced each other. Their solid-state [4 + 4] photocycloaddition was carried out, and their reactivity was considered based on geometrical parameters (distances, angles, and torsion angles) obtained from the single-crystal X-ray analysis.
An Efficient Synthetic Method of 1-(2,4,6-Tri-t-butylphenyl)-3-phenyl-1-phosphaallenes [Mes*P=C=CR–Ph; R = H, SiMe3] from Dibromophosphaethene [Mes*P=CBr2] (Mes* = 2,4,6-t-Bu3C6H2)
Authors: Ito Shigekazu , Sekiguchi Satoshi , Freytag Matthias , Yoshifuji Masaaki 
Published: June 2005

Abstract
2-Bromo-3-phenyl-1-(2,4,6-tri-t-butylphenyl)-3-trimethylsiloxy-1-phospha-1-propene reacted with t-butyllithium and chlorotrimethylsilane to afford 3-phenyl-1-(2,4,6-tri-t-butylphenyl)-1-phosphaallene and/or 3-phenyl-3-trimethylsilyl-1-(2,4,6-tri-t-butylphenyl)-1-phosphaallene through the elimination of lithium trimethylsiloxide or hexamethyldisiloxane. The molecular structure of the latter phosphaallene was confirmed by X-ray crystallography.
Time-Resolved Chemiluminescence of Luminol Induced by TiO2 Photocatalytic Reactions
Authors: Wu Xing-Zheng , Akiyama Keiko , Min Lingyue 
Published: June 2005

Abstract
The time-resolved chemiluminescence (CL) of luminol in TiO2 photocatalytic reactions is reported. Third-harmonic light of 355 nm from a Q-switched Nd:YAG laser was used as a UV light source, and CL was collected in the perpendicular direction to the excitation light by two lenses. After eliminating the scattering light, the CL was detected by a PMT and recorded on a digital oscilloscope. It was found that the CL of luminol induced by the photocatalytic reaction increased with time after the illumination of a pulse laser, and reached the maximum value at about 40–60 μs, then slowly decreased with time. The time-resolved CL intensity increased greatly in an oxygen-bubbled TiO2 suspension, while it decreased greatly in a He-bubbled one. The total CL intensity increased linearly with the concentration of TiO2. Scavengers of active oxygen species of •OH, •O2− and H2O2 were added into the suspension for studying the involvement of the active oxygen species. The experimental results suggest that more than about 30% of CL might have been caused by H2O2 over the total time period, while the possibility of •OH involvement was small. On the other hand, the addition of a scavenger of •O2− had a small effect on the CL in time period of 0–0.7 ms, and decreased the CL after 0.7 ms.
The Transethylation of Biphenyl with Diethylbenzenes over H-Y Zeolite
Authors: Jun Qiu , Komura Kenichi , Kubota Yoshihiro , Sugi Yoshihiro 
Published: June 2005

Abstract
The liquid-phase transethylation of biphenyl (BP) with diethylbenzenes (DEBZ; o-:m-:p- = 5:66:29) was investigated by the use of zeolites, Y (FAU), Beta (BEA), mordenite (MOR), and ZSM-12 (MTW). Because H-Y (H-FAU(11) with SiO2/Al2O3 = 11) was the most active among them, and we chose H-FAU(11) as a standard catalyst, and studied reaction parameters. Both the catalytic activity and the selectivity for 4,4′-diethylbiphenyl (4,4′-DEBP) were influenced by the reaction conditions. The selective formation of 4,4′-DEBP was observed at low temperatures; however, the selectivity for 4,4′-DEBP decreased with the temperature. The selectivity for 4,4′-DEBP in bulk products were lower than the case of encapsulated products. These results show that the catalysis occurred principally inside pores: 4,4′-DEBP was formed by the transethylation of BP and DEBZ inside the pores of H-Y zeolite. The resultant 4,4′-DEBP was easily isomerized to thermodynamically stable isomers, 3,4′- and 3,3′-DEBPs even at lower temperatures because the most acid sites of H-Y zeolite are inside large pores, and they are strong enough for the isomerization of 4,4′-DEBP. The shape-selective formation of 4,4′-DEBP at lower temperatures is due to the rapid diffusion of the least bulky isomer from the H-Y pores. DEBPs were polyethylated to polyethylbiphenyls (PEBPs), and deethylated to ethylbiphenyls (EBPs) by transethylation with DEBZ inside the pores.