bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intestinal anion exchange in marine fish osmoregulation
Authors: Grosell Martin 
Published: July 2006

SUMMARYDespite early reports, dating back three quarters of a century, of high total CO2 concentrations in the intestinal fluids of marine teleost fishes, only the past decade has provided some insight into the functional significance of this phenomenon. It is now being recognized that intestinal anion exchange is responsible for high luminal HCO3- and CO32- concentrations while at the same time contributing substantially to intestinal Cl- and thereby water absorption, which is vital for marine fish osmoregulation. In species examined to date, the majority of HCO3- secreted by the apical anion exchange process is derived from hydration of metabolic CO2 with the resulting H+ being extruded via a Na+:H+ exchange mechanism in the basolateral membrane. The basolateral H+ extrusion is critical for the apical anion exchange and relies on the Na+ gradient established by the Na+-K+-ATPase. This enzyme thereby ultimately fuels the secondary active transport of HCO3- and Cl-by the apical anion exchanger. High cellular HCO3-concentrations (&gt;10 mmol l-1) are required for the anion exchange process and could be the result of both a high metabolic activity of the intestinal epithelium and a close association of the anion exchange protein and the enzyme carbonic anhydrase. The anion exchange activity in vivo is likely most pronounced in the anterior segment and results in net intestinal acid absorption. In contrast to other water absorbing vertebrate epithelia, the marine teleost intestine absorbs what appears to be a hypertonic fluid to displace diffusive fluid loss to the marine environment.
Functional imaging of dolphin brain metabolism and blood flow
Authors: Ridgway Sam , Houser Dorian , Finneran James , Carder Don , Keogh Mandy , Van Bonn William , Smith Cynthia , Scadeng Miriam , Dubowitz David , Mattrey Robert , Hoh Carl 
Published: July 2006

SUMMARY
This report documents the first use of magnetic resonance images (MRIs) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep. Diazepam has been shown to induce unihemispheric slow waves (USW), therefore we used functional imaging of dolphins with and without diazepam to observe hemispheric differences in brain metabolism and blood flow. MRIs were used to register functional brain scans with single photon emission computed tomography (SPECT)and positron emission tomography (PET) in trained dolphins. Scans using SPECT revealed unihemispheric blood flow reduction following diazepam doses greater than 0.55 mg kg-1 for these 180-200 kg animals. Scans using PET revealed hemispheric differences in brain glucose consumption when scans with and without diazepam were compared. The findings suggest that unihemispheric reduction in blood flow and glucose metabolism in the hemisphere showing USW are important features of unihemispheric sleep.
Functional scans may also help to elucidate the degree of hemispheric laterality of sensory and motor systems as well as in neurotransmitter or molecular mechanisms of unihemispheric sleep in delphinoid cetaceans. The findings also demonstrate the potential value of functional scans to explore other aspects of dolphin brain physiology as well as pathology.
The Occurrence of a D–D Mechanism in the Ethanol Solution of Eosine
Authors: Nemoto Masae , Usui Yoshiharu , Koizumi Masao 
Published: July 2006

Abstract
The occurrence of a D–D mechanism in which the photochemical reaction is initiated by the interaction of the triplet dye and the ground-state dye molecules, has been established for the ethanol solution of eosine. Chief evidence for it has been afforded by: 1) the predominance of the second-order reaction at high dye concentrations, 2) the dependence of the quantum yield of the photoreduction upon the dye concentration, and 3) the effect of the dye concentration on the photochemical oxygen absorption and on the oxydative photobleaching of dye. Assuming no simple deactivation between the triplet dye and allylthiourea, the quantum yield for the formation of the triplet dye has been evaluated as 0.056. Then the rate constants for the following elementary reactions, (Remark: Graphics omitted.) and DT+ATU→intermediate are, respectively, 1×108 m−1sec−1 and 1–2×105 m−1sec−1. It seems that the reaction between oxygen and the triplet dye is chiefly an eventual deactivation of the latter, with no appreciable decomposition of the dye or of ethanol.
The Reactions between a Rhenium Filament and Oxygen at High Temperatures and Low Pressures
Authors: Hamamura Takuya , Tomita Genzo 
Published: July 2006

Abstract
The rate of the reaction of oxygen with a rhenium filament under a filament temperature of (1500–2100)°K and an oxygen pressure of (2×10−4–4×10−6)mmHg have been measured with a flow method. The reaction rate increases with an increase in the temperature, reaches zu maximum at about 1800°K, and then decreases with a further increase in the temperature. The reaction rate is proportional to the 0.9th power of the oxygen pressure below 1700°K, whereas it is proportional to the 1.8th power above 1900°K. The apparent compositions of the rhenium oxides produced in the reaction have been determined from the weight change of the filament, and the oxides in the formulas of Re2O7 and ReO3 have been found. For purposes of comparison, the reaction rates of oxygen with a tungsten filament have also been measured by the same method.
Semi-Empirical SCF Molecular Orbital Treatment for Valence Electron Systems. II. Small Ionic Intermediates
Authors: Yonezawa Teijiro , Kato Hiroshi , Konishi Hideyuki 
Published: July 2006

Abstract
Familiar small ionic intermediates are treated by the semi-empirical SCF method previously proposed for all valence electron systems by the present authors. The calculated orbital energies are compared with the results of other full SCF calculations and the experiments. The agreements between them are satisfactory. Utilizing the calculated orbital charge distributions and the atomic dipole values, the reactivities and the most reactive centers of these ions are discussed. The calculated results on the proton affinities and the excitation energies of various compounds are also presented.
Studies of the Photochemistry of Aromatic Diazo Compounds. III. The Electronic Structures of Some m-Substituted Benzenediazonium Cations
Authors: Sukigara Mitsunori , Kikuchi Shin-ichi 
Published: July 2006

Abstract
The electronic structures and electronic absorption spectra of m-fluoro-, m-chloro-, m-bromo-, and m-methoxybenzenediazonium cations were studied by making molecular orbital calculations, and by measuring the near-ultraviolet absorption spectra. From the calculations it is understood that when an electron-donating group is introduced at the m-position of the benzenediazonium cation, a mixing of the lowest locally-excited 1B1 state within the benzenediazonium cation and the intramolecular charge-transfer state arising from the electron transfer from the electron-donating group at the m-position to the lowest unoccupied molecular orbital of the benzenediazonium framework comes to show a large contribution of the substituted cation in the lowest excited state while at the same time the energy of the corresponding state is lowered. The ground and the excited 1A1 states of the nonsubstituted cation are not so greatly affected by the m-substitution as is the 1B1 state. The degree of the mixing of the 1A1 and 1B1 state of the benzenediazonium cation by the m-substitution is not so impotant in the ground and lower excited states of the m-substituted benzenediazonium cation.
Effect of Nitrous Oxide on the Radiolysis of Liquid Methanol with the Recoils from the 10B(n, α)7Li Reaction
Authors: Imamura Masashi , Seki Hiroshi 
Published: July 2006

Abstract
Liquid methanol containing trimethyl borate and nitrous oxide was irradiated with thermal neutrons from a nuclear reactor. In contrast to the marked effect on the γ-radiolysis yields, nitrous oxide had a little effect on the recoil radiolysis yields from methanol, and nitrogen yield was as low as 0.2 in G unit. These results indicate that the yield of the solvated electron in the recoil radiolysis of methanol is about one tenth of that in the γ-radiolysis.
The Reaction between Mercury(II) and Organic Compounds. II. The Composition of a Mercury(II)-l-Histidine Complex in an Ethanol-Water Solution
Authors: Kai Fumiaki 
Published: July 2006

Abstract
The composition of the complex formed with l-histidine and mercury(II) in a solution has been investigated spectroscopically. The complex formation in an aqueous solution was not observed, but in an alcoholic solution (1 : 1), there appeared about 274 mμ an absorption maximum which can be attributed to the complex formation. By the spectroscopic measurements of this alcoholic solution containing two components in various proportions, it was shown that only one kind of complex with a 1 : 1 composition was formed in a 50% ethanol-water solution at pH 3.25–3.75 and at 20°C. Accordingly, the composition of the complex may be considered to be as follows:
(Remark: Graphics omitted.)
Crystalline Complex of Allyl Alcohol with Copper(I) Chloride
Authors: Ogura Tetsuya , Furuno Nobuo , Kawaguchi Shinichi 
Published: July 2006

Abstract
A colorless crystalline complex of allyl alcohol with copper(I) chloride, (CH2=CHCH2OH)-CuCl, was synthesized at room temperature in a vacuum system. A similar complex with calcium chloride was also prepared for the sake of comparison. The equilibrium vapor pressure of the copper (I) chloride complex was determined at vairous temperatures, and ΔH=−12.0 kcal/mol was obtained as the heat of formation from solid copper (I) chloride and gaseous allyl alcohol. The C=C stretching frequency of allyl alcohol is shifted by 95 cm−1 to the lower frequency side by ligation to copper (I). The C–O stretching band shows a very minor shift of 15 cm−1. This value is almost the same as in the calcium chloride complex. Thus, in the copper (I) chloride complex, allyl alcohol coordinates to the metal mainly through the double bond, but the OH group also participates in the coordination. By measuring the decrease in vapor pressure, copper(I) chloride was found to exist as a dimer in allyl alcohol at 23–43°C, but as a monomer at 97°C.
Mechanistic Aspects of the Formation and Decomposition of the Cyclic Anhydride of β-Sulfopropionic Acid. A Study of Radical Rearrangement Using a Labeled Compound
Authors: Nagai Toshikazu , Nishitomi Katsuhiko , Tokura Niichiro 
Published: July 2006

Abstract
The photochemical sulfonation of propionic-α, α-d2-acid-d1 (83% isotopic purity at the α-position) with sulfuryl chloride to form the cyclic anhydride of the deuterated β-sulfopropionic acid was carried out. The isotopic purity of the resulting anhydride decreased to 55±2% at the α-position. This result indicates that an α-hydrogen is abstracted in a ratio of 67.5±5%, followed by the rearrangement of a β-hydrogen prior to the sulfonation at the β-carbon atom. The mechanism is somewhat different from that proposed by Kharasch et al. [M. S. Kharasch, T. H. Chao and H. C. Brown, J. Am. Chem. Soc., 62, 2393 (1940)] for the photosulfonation of propionic acid. The present paper will also study the thermal decomposition of the cyclic anhydride to produce acrylic acid; its mechanistic aspects will be considered.
Considerations on the Nuclear Magnetic Resonance Spectra of Some Anomeric Tetra-O-acetyl-d-glucopyranosides
Authors: Tsuzuki Yojiro , Tanaka Katsumi 
Published: July 2006

Abstract
We have measured the nuclear magnetic resonance spectra (NMR) of some anomers of aryl 2,3,4,6-tetra-O-acetyl-d-glucopyranosides and found that the signal of the anomeric proton in the α-anomers could be separated from the signals due to the other protons, and that the chemical shift in fact distinctly appeared in a lower mangetic field (δ=5.95 ppm, J=3.0 to 3.5 cps) than those in alkyl 2,3,4,6-tetra-O-acetyl-d-glucopyranosides. Lower field shifts have also been observed in β-anomers, but it was impossible to determine the chemical shift exactly possibly because of the overlapping with the signals due to the other protons attached to the pyranose ring.
An Investigation of the Mechanism of the Henkel Reaction by Deuterium and Carbon-14 Isotope Techniques
Authors: Furuyama Shozo 
Published: July 2006

Abstract
The thermal rearrangements and the disproportionation of potassium benzenecarboxylates have been investigated at 350–460°C using potassium deuterophthalate, deuterobenzoate, benzoate-1-14C and benzoate-7-14C. The following results were obtained: (1) Hydrogen atoms of potassium phthalate and benzoate transfer intermolecularly during the conversion. The hydrogen atoms seem to exchange many times. (2) The intermolecular transfer of hydrogen atoms also takes place between different benzenecarboxylates. (3) The hydrogen atoms transfer intermolecularly many times, irrespective of either the reaction temperature, the kinds of catalysts, and the kinds of potassium carboxylates. (4) The hydrogen exchange takes place only during the conversion. (5) Many of the carboxyl groups of potassium benzoate are replaced by carbon dioxide in the gas phase and by carbon dioxide from potassium carbonate. A possible mechanism is presented.
Studies of the Model Compounds of Cyclopolymers. An NMR Spectroscopic Study of cis and trans Isomers of 2, 5-Dimethoxytetrahydrofuran
Authors: Aito Yuzo , Matsuo Taku , Aso Chuji 
Published: July 2006

Abstract
The configurational isomers of 2, 5-dimethoxytetrahydrofuran were synthesized as model compounds of the cyclopolymer of succinaldehyde. The NMR spectra of the isomers were then studied in carbon tetrachloride and in benzene. From the behavior of the methyl and methylene protons of the isomers in chemical shifts and in the formation of a “loose-complex” with benzene, it was concluded that the isomer with the lower boiling point had a trans configuration and that the isomer with the higher boiling point had a cis configuration. The NMR spectrum of 2, 5-dimethoxy-2, 5-dihydrofuran was similarly investigated in order to compare it with that of 2, 5-dimethoxytetrahydrofuran. The spectrum was rather simple; each signal was assigned to the cis or to the trans configurational isomer.
ESR Studies on the Behavior of Fluorescein Semiquinone
Authors: Okuda Michio , Momose Yoshihiro , Niizuma Shigeya , Koizumi Masao 
Published: July 2006

Abstract
The structure and reactivity of different types of fluorescein semiquinone were studied in an alkaline solution pH 11–14, by the ESR method. The hyperfine structures with more than fifty lines are semiquantitatively interpreted by the McLachlan method. The three lines with the largest splitting constant, 3.44G, were attributed to the protons at the next neighboring carbon atoms (on the outside benzene ring) from the central carbon atom. The decay of semiquinone obeys the second order, but the rate constant depends largely on the pH. This difference was attributed to the difference in the reactivities of semiquinone monoanion, dianion, and trianion. The activation energy, however, was found to be about 10–12 kcal/mol, regardless of the pH. In order to interpret the above results a mechanism was proposed in which the essential process is the recombination of two radical anions at the position of the central carbon atoms. Evidence for this mechanism was afforded by the calculation of the delocalization energy for the above process, which has proved to be almost constant for different species of semiquinone.
Electronic Structures and Luminescence Properties of Phenazine Derivatives
Authors: Mataga Noboru , Ezumi Kiyoshi 
Published: July 2006

Abstract
The electronic structures and luminescence properties of phenazine derivatives (1, 5-dichloro-, -dihydroxy-, -dimethoxy-, and -diamino-phenazine) have been studied. The observed absorption spectra and the solvent effects on the spectra have been interpreted satisfactorily on the basis of the quantum mechanical calculation of the pi-electronic states of these molecules. From the results of this calculation, as well as from the fluorescence properties of these molecules, it has been established that the lowest excited singlet state is 1(π–π*) (the 1La state more or less modified by the substitution) in all of these molecules, in contrast to the case of the phenazine molecule, where 1(n–π*) is the lowest singlet excited state, leading to the non-fluorescent property of this molecule. The effects of hydrogen bonding and acid-base interactions on the fluorescence properties of the phenazine derivatives have been examined. The inter and intra-molecular hydrogen bonding as well as the protonation interactions at the ring nitrogen cause, in general, a large decrease in the fluorescence yields of these molecules, in contrast to the case of acridine and acridine derivatives, where the interactions with aliphatic alcohols and acids affect the fluorescence yield only slightly or even increase it. The mechanism of this fluorescence quenching has been discussed on the basis of a radiationless vibronic coupling between the relevant electronic states.
Catalytic Decomposition of Methanol over Nickel Wire
Authors: Yasumori Iwao , Nakamura Tetsuro , Miyazaki Eizo 
Published: July 2006

Abstract
The kinetic studies of the decomposition of methanol have been undertaken under pressures of up to 20 mmHg and at temperatures between 300 and 430°C. The initial rate (r0) of decomposition which turns methanol into carbon monoxide and hydrogen was found to be expressed by the equation, r0=aPm⁄(1+b\sqrtPm)2 where Pm is the initial pressure of methanol and where a and b are constants. The addition of carbon monoxide to the reactant was found to depress the rate of reaction, while a slight promotion was observed upon the addition of hydrogen to the system. On the other hand, when the kinetics of the decomposition of formaldehyde, which was regarded as the intermediate product in the methanol decomposition, was studied, it was found that formaldehyde decomposed to cabon monoxide and hydrogen, and that the rate was much larger than that of methanol decomposition. On the basis of these results and the exchange reaction of methanol with deuterium, the processes of methanol decomposition were discussed in detail and a possible mechanism of reaction was proposed in which the surface reaction between the adsorbed methoxy radical and the hydrogen atom, both produced by the dissociative adsorption of methanol, is the rate-determining step of the reaction.
Nickel(II), Cobalt(II) and Copper(II) Complexes of 2,2′-Diaminobiphenyl
Authors: Onaka Satoru , Iwamoto Toschitake , Sasaki Yukiyoshi , Fujiwara Shizuo 
Published: July 2006

Abstract
Nickel(II), cobalt(II) and copper(II) complexes of 2, 2′-diaminobiphenyl were prepared in an autoclave under a high pressure and a high temperature as the acetates: Ni(C12H12N2)2-(CH3CO2)2, Co(C12H12N2)2(CH3CO2)2 and Cu(C12H12N2) (CH3CO2)2. They are sparingly soluble in water and in non-polar solvents, but are soluble in some polar solvents. The presence of a monomer complex was verified by a molecular weight determination in a methyl ethyl ketone solution for both the cobalt and copper complexes. Analytical, magnetic susceptibility, powder X-ray diffraction, diffuse reflection spectral, infrared spectral, and ESR spectral data are given, and the geometric isomerism of the complexes is discussed.
Studies on the Chemical Constitution of Agar-agar. XXIV. Isolation of a New Disaccharide as a Reversion Product from Acidic Hydrolysate
Authors: Araki Choji , Arai Kiyoshi 
Published: July 2006

Abstract
The careful separation of the products of the complete hydrolysis of commercial agar on charcoal-Gelite columns has led to the isolation of a new reducing disaccharide, named “isoagarobiose,” in a yield of 1.5% of the agar sample. Its crystalline phenylosazone and crystalline hexa-acetate have also been prepared. On methanolysis the disaccharide gave methyl d-galactoside and 3, 6-anhydro-l-galactose dimethyl acetal. Complete methylation, followed by methanolysis, yielded 2, 4, 5-tri-O-methyl-3, 6-anhydro-l-galactose dimethyl acetal and methyl 2, 3-di-O-methyl d-galactoside. It follows from these results that the disaccharide has an unusual structure, in which the C1 of the 3, 6-anhydro-aldehydo-l-galactose residue is linked, through cyclic acetal linkages, with the C4 and C6 of the d-galactose residue. Evidence is provided that the disaccharide is not involved in the polysaccharide molecule, but has been formed by acid reversion from d-galactose and 3, 6-anhydro-l-galactose during the hydrolysis of the polysaccharide. The formation of the cyclic acetal linkages is accounted for in terms of the peculiar property of the anhydrosugar, which exists in an aldehyde form, with an open-chain structure.
The Dehydrogenation of ortho-Tropylphenols and the Synthesis of Furano-p-benzoquinonetropides
Authors: Nozoe Tetsuo , Takahashi Kazuko 
Published: July 2006

Abstract
The intermolecular disproportionation reaction between 2-methoxy-10aH-cyclohepta-[b]benzofuran (4) and 2-acetoxy-3-methoxyphenyltropylium ion (2) occurred upon the treatment of 2 with 2 n hydrochloric acid, thus affording 3′-methoxy-2′, 2-epoxyphenyltropylium ion (5) and 3-(2-acetoxy-3-methoxyphenyl)tropilidene (6). 3H-Cyclohepta[b]benzofuran-3-one (furano-p-benzoquinonetropide) (25), its ethyl (30), chloro (35), acetyl (40) and hydroxy (48) derivatives were synthesized by the application of this disproportionation reaction to the dehydrogenation products of 4-tropyl, 6-ethyl-4-tropyl, 6-chloro-4-tropyl, 6-acetyl-4-tropyl resorcinol and 4-tropylphroglucinol triacetate respectively. The electronic spectra of these furano-p-benzoquinonetropides (25), (30), (35), and (40), in water showed their long wavelength absorption maxima at mμ (logε) values of 540 (3.74), 568 (3.57), 512 (3.83) and 512 (3.51) respectively. However the spectra of these compounds in chloroform showed the peaks at mμ (logε) values of 635 (3.03), 685 (3.61), 665 (3.56) and 600 (3.50) respectively, the peaks had shifted to wave-lengths longer by 100–150 mμ than those in water. This solvent effect, the reverse of the case of p-benzoquinonetropides, may be interpreted in terms of an increased contribution by the polar structure to the ground state as a result of the formation of the furan ring.
Correlation of the Physical Properties of Organophosphorus Compounds. I. Density, Boiling Point, and the Heat of Evaporation of Phosphines
Authors: Arshad M , Beg A 
Published: July 2006

Abstract
The boiling point and density of the phosphines have been correlated by using the quantity Mρ2. The use of such data permits the classification of these compounds into associated and normal liquids. These conclusions are also supported by the study of the heat of evaporation of the phosphines.
Antituberculous Compounds. XXV. Some Derivatives of Pyrido[2, 3-d]pyridazine
Authors: Kakimoto Shichiro , Tonooka Shuichi 
Published: July 2006

Abstract
Attempts to prepare 5, 6-dihydropyrido[2, 3-d]pyridazin-8(7H)-one by the hydrogenation of pyrido[2, 3-d]pyridazin-8(7H)-cne were not successful, but it was found that the hydrogen-ated compound was 1, 2, 3, 4-tetrahydropyrido[2, 3-d]pyridazm-8(7H)-one. The same reaction occurred in the case of pyrido[2, 3-d]pyridazin-5(6H)-one and some other derivatives.
The Crystal Structure of 2-Anilino-3-bromo-tetrahydro-exo-dicyclopentadiene
Authors: Tanaka Nobuo , Ashida Tamaichi , Sasada Yoshio , Kakudo Masao , Kasai Nobutami 
Published: July 2006

Abstract
2-Anilmo-3-bromo-tetrahydro-exo-dicyclopentadiene, C16H20NBr, crystallizes in the monoclinic space group P21⁄c, with four molecules in a unit cell of dimensions a=9.15, b=17.36, c=9.56 Å, β=108.45°. The structure was solved by superimposing the minimum function upon the first Fourier map based on the Br atom only. The atomic parameters were refined by the block-diagonal least-squares method. Most of bond-angles of carbon atoms forming a tricyclic system in the molecule are somewhat smaller than the ordinary tetrahedral angle, particularly on the bridged carbon atom. The Br atom is bonded to the endo side of the ring and the N atom to exo.