bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics and Diffusing Species of the High-Temperature Selenidization of Molybdenum
Authors: Wakatsuki Noboru , Sasaki Yoshinori 
Published: July 2006

Abstract
A molybdenum sheet was selenidized at a selenium vapor pressure of 0.40—13.3 kPa at 773—973 K by means of a sealed-tube method. X-Ray diffraction patterns and an electron probe microanalysis of the product films showed that a single layer comprising MoSe2 was formed under all of the selenidization conditions employed. All of the selenidizations obeyed a parabolic rate law and, therefore, the rate-determining step was apparently a diffusion process. The parabolic rate constant (Kp) was expressed as a function of the absolute temperature, and the selenium vapor-pressure dependence of Kp could be clearly recognized. A marker experiment indicated that selenium was the component which diffused.
Solution Equilibria of Binary and Ternary Zinc(II) Halogeno Complexes in N,N-Dimethylacetamide
Authors: Suzuki Honoh , Koide Makoto , Ishiguro Shin-ichi 
Published: July 2006

Abstract
Solution equilibria between zinc(II) and halide ions have been studied in N,N-dimethylacetamide (DMA) by calorimetry at 298 K. Formation constants, enthalpies, and entropies of mononuclear binary complexes, [ZnIICln](2−n)+ (n = 1—4), [ZnIIBrn](2−n)+ (n = 1—3), and [ZnIIIn](2−n)+ (n = 1,2), have been determined. In addition, mixed-ligand complexes have been detected in ternary Zn–Cl–Br and Zn–Br–I systems: [ZnClBr], [ZnCl2Br]−, [ZnClBr2]−, and [ZnBrI]. Complexation is more favorable and more exothermic in the order Cl &gt; Br &gt; I. Formation of the monohalogeno complexes is particularly endothermic and entropy-productive, suggesting that geometric transition from octahedral to tetrahedral is complete at this step, i.e., all the halogeno complexes are tetrahedral. Thus, the transition occurs earlier in DMA than in N,N-dimethylformamide (DMF). Compared with DMF, complexation in DMA is more favorable and more exothermic exclusively at the first and second steps, and little difference is found for the later steps. This is attributed to the steric hindrance of DMA molecules, which is crucial in octahedral coordination structures but not important in tetrahedral geometry. Among the first-row bivalent transition metal ions, ZnII is exceptional in its ΔHβ4° and ΔSβ4° values of overall formation of the tetrachloro complex, consistent with the existence of a solvation equilibrium: [Zn(dma)6]2+ [Zn(dma)4]2+ + 2dma.
Phase Separation in Silica Sol–Gel System Containing Poly(ethylene oxide). I. Phase Relation and Gel Morphology
Authors: Nakanishi Kazuki , Komura Hiroshi , Takahashi Ryoji , Soga Naohiro 
Published: July 2006

Abstract
Phase separation and gelation behaviors have been studied for the acid-catalyzed, alkoxide-based silica systems containing poly(ethylene oxide) (PEO) with an average molecular weight of 100000. Gels with micrometer range interconnected porous morphology were obtained similarly to the systems containing other water-soluble polymers, in which the structure development by the spinodal decomposition and the gel forming process take place concurrently. In spite of the morphological similarity, the thermogravimetric analysis revealed that the reacting solution decomposed into phases one rich in PEO and the other rich in solvent. Macropore volume of gels depended mainly on the amount of solvent phase.
Concentration- and Structure-Dependent Effects of Amides on Protease Activity in Organic Solvents
Authors: Yamamoto Yasuhito , Kise Hideo 
Published: July 2006

Abstract
The catalytic activity of α-chymotrypsin (CT) in the transesterification of N-acetyl-l-tyrosine methyl ester to its ethyl ester in aqueous-organic media was markedly enhanced by replacing a part of water with formamide. The activity of CT was strongly dependent on the formamide/water ratio, and excess formamide retarded the activity. Addition of formamide to reaction mixtures at constant water contents exhibited similar activation–deactivation profiles for CT. A kinetic study revealed that the rate acceleration is due to an increase in kcat rather than a change in Km. At a given concentration of amides (0.5 M, M = mol dm−3), propionamide and DMF were much less effective than formamide for activation of CT. The results suggest that formamide interacts with CT in a different way from water.
Studies on Synthesis of Antibacterial Agent (NM441). I. Kinetics and Mechanism of the Reaction of 4-(Bromomethyl)-5-methyl-1,3-dioxol-2-one with 1-Substituted Piperazine (NM394)
Authors: Nishida Hiroshi , Fujii Tatsuya , Abiru Yoshiaki , Yatsuki Katsuya , Yamamoto Masashi , Shimizu Naoki , Kakemi Kazuo , Mikawa Miyako , Kise Masahiro 
Published: July 2006

Abstract
When a tertiary amine (4,NM441) is synthesized from 4-bromomethyl-5-methyl-1,3-dioxol-2-one (DMDO-Br) and a secondary amine (3,NM394) in N,N-dimethylformamide (DMF), the quaternary ammonium salt 5, the ring-opened compound 6, and the 1,2-adduct 7 are formed as by-products. The tertiary amine 4 is formed by nucleophilic attack of 3 on the α-carbon to the bromine atom of DMDO-Br. The ring-opened compound 6 is formed by nucleophilic attack of 3 on carbonyl carbon of DMDO-Br. The quaternary ammonium salt 5 is formed by the reaction of DMDO-Br with 4 (the Menshutkin reaction). Main pathway for the formation of 7 is the Michael addition of 3 to 6. Kinetics of the reactions have been studied and the methods to obtain 4 suppressing the formations of 5, 6, and 7 have been proposed based on the kinetic results.
Second-Harmonic Generation from Single and Mixed Crystals of p-Nitroaniline and Its Derivatives
Authors: Matsushima Ryoka , Hiramatsu Kiyonari , Shimamoto Katsuhisa 
Published: July 2006

Abstract
Noncentrosymmetric and thermostable single crystals (space group of Pna21) of N-(2-butenyl)-p-nitroaniline were obtained by slow crystallization from solution, with SH activities of 150—200 × urea measured by the SHG powder method with a 1064 nm Nd : YAG laser source. Single crystals of N-(3-methyl-2-butenyl)-, N-(2-propenyl)-, or N-butyl-p-nitroaniline showed nil SH activities. On the other hand, mixed crystals of these derivatives with p-nitroaniline showed much higher SH activities (up to 2000), though thermally not stable.
New Synthetic Methods and Reagents for Complex Carbohydrates. IX. Aryl d-Glucopyranosides and 1-Aryl-1-deoxy-d-glucopyranoses from 2,3,4,6-Tetra-O-benzyl-α-d-glucopyranosyl Dimethylphosphinothioate
Authors: Yamanoi Takashi , Fujioka Ayumi , Inazu Toshiyuki 
Published: July 2006

Abstract
The reactions of 2,3,4,6-tetra-O-benzyl-α-d-glucopyranosyl dimethylphosphinothioate and phenolic compounds gave the corresponding aryl α-d-glucopyranosides predominantly in good yields, even when the trimethylsiloxy derivatives of benzene, which are known to afford 1-aryl-1-deoxy-d-glucopyranoses by the conventional methods, were used as acceptors. On the other hands, 1-ary-1-deoxy-β-d-glucopyranose was obtained in good yield when 1,3,5-trimethoxybenzene was used as an acceptor.
Pressure Effect on the Inter- and Intramolecular Vibrations of 1,2,4,5-Tetrachlorobenzene Crystal
Authors: Matsukuma Sinichiro , Kawano Hiroshi , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
The effect of pressure on the frequencies and band structures of the Raman active inter- and intramolecular vibrations of the 1,2,4,5-tetrachlorobenzene crystal was studied under hydrostatic pressures upto 4 GPa at 300 K in a gasketed diamond anvil cell. Changes of the Raman frequencies and band structures of the vibrations suggest that the phase transition takes place under about 0.7 GPa. The frequency shift of the intramolecular vibrations induced by pressure was calculated using an intermolecular potential of the atom–atom type based on the two-site molecular exciton theory. The calculation shows that the observed pressure-induced frequency shift is mainly caused by the repulsive force between the chlorine atoms belonging to the adjacent molecules.
Structural Essentials of Ser-1 in Tethered Peptide Ligand of Human Thrombin Receptor for Phosphoinositide Hydrolysis
Authors: Sakaguchi Kazuyasu , Kodama Hiroaki , Ogino Yoshio , Costa Tommaso , Nose Takeru , Shimohigashi Yasuyuki 
Published: July 2006

Abstract
In order to inspect the structural elements of Ser-1 in receptor activation by SFLLRNP (one-letter amino acid code), a ligand peptide tethered to the thrombin receptor, a series of analogs with such replacements as d-Ser, Ala, Thr, and Ac-Ser have been synthesized. These analogs were evaluated for their ability to hydrolyze the phosphoinositide in human neuroblastoma SH-EP cells. It was found that the α-amino group and l-configuration of Ser-1 are very important in the activation of receptors. N-Acetylation or deletion of Ser-1 completely eliminated the activity of SFLLRNP (a half-maximal effective concentration, EC50 = 0.89 μM (1 M = 1 mol dm−3)), and these modifications induced no antagonist activity. Incorporation of d-Ser also drastically diminished the activity, but retained about 50% activity of the maximal response by 100 μM SFLLRNP. The Ser/Ala substitution sustained 30% of the activity of SFLLRNP to elicit a full stimulation. The Ser/Thr substitution, however, enhanced the activity (20%) in spite of its decreased activity (60%) reported for platelet aggregation. These results indicated that the β-hydroxyl group of Ser-1 is important to receptor activation, but not essential. The effect of chemical modifications on the receptor activities of the tethered ligand is discussed with regard to the efficacy between phosphoinositide hydrolysis and biological activities.
Generation of 2-Lithio-2-(trimethylsilyl)silacyclopentane and 2-Lithio-2-(phenylthio)silacyclopentane and Their Use for the Synthesis of 1,4-Butanediols and γ-Hydroxy Ketones
Authors: Matsumoto Kozo , Yokoo Toshiaki , Oshima Koichiro , Utimoto Kiitiro , Rahman Noorsaadah Abd 
Published: July 2006

Abstract
Treatment of 2-(trimethylsilyl)silacyclopentane with t-butyllithium in THF–HMPA gave 2-lithio-2-(trimethylsilyl)silacyclopentane in good yield. An addition of alkyl iodides to the lithium compound provided 2-alkyl-2-(trimethylsilyl)silacyclopentanes which were converted into 1-alkyl-1,4-butanediols upon treatment with H2O2–KF and successively with n-Bu4NF. Reaction of 2-lithio-2-(trimethylsilyl)silacyclopentane with aldehydes gave 2-alkylidenesilacyclopentanes, which were transformed into γ-hydroxy ketones by oxidative cleavage of carbon-silicon bonds. 2-Lithio-2-(phenylthio)silacyclopentane, derived from 2-(phenylthio)silacyclopentane and t-butyllithium, afforded alkenyl sulfides having silylalkyl substituent upon treatment with aldehydes. Oxidative cleavage of carbon–silicon bonds followed by hydrolysis of alkenyl sulfide moiety also provided γ-hydroxy ketones.
Practical Preparation of (Z)-2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-methoxyiminoacetic Acid: A Side-Chain of the Fourth Generation of Cephem Antibiotics
Authors: Tatsuta Kuniaki , Miura Shozo , Gunji Hiroki , Tamai Tetsuro , Yoshida Ryonosuke , Inagaki Takashi , Kurita Yasuyuki 
Published: July 2006

Abstract
A Z-isomer (4) of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetic acid, which is the common acyl moiety of clinically useful cephem antibiotics, has been prepared from the aminoisoxazoles through the skeletal rearrangement in several routes. Reaction of 3-amino-5-methoxyisoxazole (7) with alkoxycarbonyl isothiocyanates gave methyl 2-(5-alkoxycarbonylamino-1,2,4-thiadiazol-3-yl)acetates (8), which were converted into the target compound 4 through the reaction of the corresponding keto ester with O-methylhydroxylamime. Compound 4 was prepared similarly from 3-aminoisoxazole (10). Also, O-methylation of 2-hydroxyimino-2-(5-methoxycarbonylamino-1,2,4-thiazol-3-yl)acetate (15) with methyl iodide or dimethyl sulfate in the presence of barium oxide and barium hydroxide octahydrate was found to afford exclusively the desired Z-isomer (14a) of methyl 2-(5-methoxycarbonylamino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetate, which was led to 4.
Diastereo- and Enantioselective Synthesis of syn- and anti-1,2-Diol Units by Asymmetric Aldol Reactions
Authors: Mukaiyama Teruaki , Shiina Isamu , Uchiro Hiromi , Kobayashi Shu 
Published: July 2006

Abstract
syn- and anti-1,2-Diol units were prepared by using asymmetric aldol reactions of the silyl enol ethers derived from α-alkoxythioacetic S-esters with aldehydes. In the presence of tin(II) triflate, a chiral diamine, and dibutyltin diacetate, (Z)-2-benzyloxy-1-ethylthino-1-(trimethylsiloxy)ethene reacted with aldehydes to afford the corresponding anti-aldol adducts in high yields with excellent diastereo- and enantioselectivities, while syn-adducts were obtained from (Z)-2-(t-butyldimethylsiloxy)-1-ethylthio-1-(trimethylsiloxy)ethene and aldehydes under the same reaction conditions. Thus, both diastereomers can be synthesized in excellent enantiomeric excesses by simply choosing the protective groups of the alkoxyl parts of the silyl enol ethers.
Preparation and Magnetic Properties of Dicopper(II) Hydroxide Tris(pyrazolide)s
Authors: Emori Shuji , Sadakata Kazutoshi 
Published: July 2006

Abstract
Dicopper(II) hydroxide tris(pyrazolide)s Cu2(OH)(4-Xpz)3 (pz = pyrazolide ion; X = H, CH3, Cl, Br) and Cu2(OH)(4-Xpz)3(4-XpzH)2 (X = Cl, Br) were prepared and characterized by means of magnetic susceptibility and IR spectroscopy. Their magnetic-moment values increased in the substituent sequence X = CH3 &lt; H &lt; Br ≈ Cl, and were correlated with the basicities and coordinating angles of the pyrazolido ligands.
Photochromism of 1,1-Diaryl-1-alkanols
Authors: Matsui Masaki , Tsuge Michinori , Shibata Katsuyoshi , Muramatsu Hiroshige 
Published: July 2006

Abstract
1,1-Bis[4-(dimethylamino)phenyl]-1-alkanols were found to show photochromism.
Chemoselective Reactions of Tellurium Tetraethoxide towards Thioamides and Amides
Authors: Omote Kazushi , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio 
Published: July 2006

Abstract
Tellurium tetraethoxide reacts with primary thioamides at room temperature, forming nitriles in high yields. On the other hand, the reactions with amides are largely temperature-dependent, giving predominantly esters at 80 °C and nitriles at a higher temperature. Similarly, tellurium tetraethoxide readily induces the C–N bond cleavage of ureas to give carbamates and amines.
Convenient Chemical Actinometer with 2-Hydroxy-4′-methoxychalcone
Authors: Matsushima Ryoka , Mizuno Hirotaka , Kajiura Atsushi 
Published: July 2006

Abstract
The quantum yields for the photochemical conversion of 2-hydroxy-4′-methoxychalcone into the flavylium ion are in the range of 0.25—0.35 in acetic acid and 0.14—0.2 in aqueous ethanol at pH 2, depending on the wavelength of UV light. The quantum yields are essentially constant against any changes in the light intensity, temperature, or substrate concentration, which is a favorable feature regarding use as a convenient chemical actinometer. A one-photon mechanism involving excited-state proton-transferred tautomer is proposed.
Intramolecular Photocycloaddition of the C=C Double Bond to the C≡N Triple Bond Resulting in the Formation of a Novel Cyclic System
Authors: Sakuragi Hirochika , Koyama Toshiya , Sakurazawa Mamoru , Yasui Norimichi , Tokumaru Katsumi , Ueno Katsuhiko 
Published: July 2006

Abstract
Irradiation of a bichromophoric 1-(o-cyanobenzyloxy)-2-(p-methoxyphenyl)-2-butene (1a) in cyclohexane gave an isoquinoline derivative, 8-methoxy-6-methyl-11,13-dihydro[2]benzoxepino[5,4-c]isoquinoline (2a). The structure was determined by X-ray analysis. The formation of 2a can be accounted for by the initial cycloaddition of 1a in the excited singlet state between the C=C double bond and C≡N triple bond, followed by cleavage of the resulting azetine ring and recyclization.
STUDIES ON REACTIONS BETWEEN GAS AND SOLID. III. AZOTATION OF CALCIUM CARBIDE AND THE EFFECT OF PRESSURE OF NITROGEN ON THE REACTION VELOCITY
Authors: Aono Takeo 
Published: July 2006

Abstract
It has been experimentally determined that the velocity of reaction between nitrogen and calcium carbide at high temperatures is not directly proportional to the nitrogen-pressure, but there exists the following relation: (Remark: Graphics omitted.) \oindentwhere P denotes the pressure, K and α certain constants depending upon temperature and other conditions of the reaction.
It has also been found that the higher the temperature the greater is the effect of pressure-increase to the velocity of reaction, though the effect of the pressure-increase becomes smaller at higher pressures. At lower pressures the velocity of the reaction is nearly proportional to the pressure.
SORPTION VELOCITY OF GAS BY POROUS SOLID
Authors: Sameshima Jitsusaburo 
Published: July 2006

Abstract
1. The sorption by porous solid of gas under constant pressure and temperature proceeds, generally, in two stages. The mechanisms of sorption of each stage are described.
2. The velocity of the former stage is expressed by the equation
(Remark: Graphics omitted.)
where x denotes the amount of gas sorbed at time t, and K, s and n are constants. In the simplest case where n=1, this equation is integrated in the following form,
(Remark: Graphics omitted.)
3. The velocity of the latter stage of sorption is expressed by x-a logt=k
where α and k are constants.
ON THE CATALYTIC ACTION OF JAPANESE ACID EARTH. VIII. THE RELATION BETWEEN THE CATALYTIC ACTIVITY AND THE ADSORPTION
Authors: Ishimura Koshiro 
Published: July 2006

Abstract
(1) The catalytic activity of Japanese acid earth on naphthalene has been compared with its adsorptive powers for water, benzene, and naphthalene.
(2) The relations between the adsorptive powers and the surface area of the earth have been discussed.
(3) It has been concluded that the larger the surface area the greater is the catalytic activity and therefore the magnitude of the catalytic activity depends upon the surface area possessing active centres equally distributed but not on the number of the active centres on the equal surface area.
(4) The influence of the chemical composition of the earth on its surface area has been suggested.
Formulary Forum: Intrathecal Ziconotide for Refractory Chronic Pain
Authors: Lynch Shalini S , Cheng Christine M , Yee Jennie L 
Published: July 2006

Objective: TO describe the pharmacology, efficacy, and safety of ziconotide for treatment of severe chronic pain in patients who are candidates for intrathecal therapy. Data Sources: A PubMed/MEDLINE search (1966–June 2006) was conducted using the terms ziconotide, Priait, and SNX-111. Manufacturer-provided data, the Food and Drug Administration medical review of ziconotide, and abstracts presented at American Pain Society meetings (2001–2006) were also reviewed. Study Selection and Data Extraction: Human studies evaluating the efficacy and safety of ziconotide for the treatment of chronic pain were considered. Animal data were excluded. Data Synthesis: Ziconotide is the first and only neuronal-type (N-type) calcium-channel blocker. Ziconotide must be administered intrathecally via continuous infusion. A programmable implanted variable-rate microinfusion device, or an external microinfusion device and catheter must be utilized. In double-blind, placebo-controlled studies, ziconotide significantly improved patient perception of pain from baseline to the end of the study periods, which ranged from 11 to 21 days. Patients enrolled in clinical trials were intolerant of or refractory to other treatment modalities. There have been no studies that directly compared ziconotide with other intrathecal or systemic analgesics. Key ziconotide-related adverse events are neuropsychiatrie, including depression, cognitive impairment, and hallucinations; depressed levels of consciousness; and elevation of creatine kinase levels. Ziconotide is also associated with a risk of meningitis due to possible contamination of the microinfusion device. Conclusions: Ziconotide is a therapeutic option for treatment of severe chronic pain in patients who have exhausted all other agents, including intrathecal morphine, and for whom the potential benefit outweighs the risks of serious neuropsychiatric adverse effects and of having an implanted device. Further studies are needed to determine the comparative efficacy of ziconotide and other pain therapies.
Pegaptanib: A Novel Approach to Ocular Neovascularization
Authors: Chapman Julie A , Beckey Cherylyn 
Published: July 2006

Objective: TO review pegaptanib, a novel aptamer for the treatment of age-related macular degeneration (AMD). Data Sources: A literature search using MEDLINE (1980–January 2006) and the Cochrane Database of Systematic Reviews (1978–January 2006) for peer-reviewed, English-language publications was conducted. Abstracts from recent meetings, including the Association for Research in Vision and Ophthalmology and American Society of Retinal Specialists, were reviewed for relevant abstracts and poster presentations. Study Selection and Data Extraction: Pharmacokinetic and pharmacology data were extracted from animal and human studies, and double-blind, randomized, controlled trials were included to describe the efficacy and adverse effects of pegaptanib. Data Synthesis: The efficacy of pegaptanib has been evaluated in 2 concurrent, prospective, randomized, double-blind trials. Patients with AMD were randomly assigned to receive placebo or pegaptanib intravitreous injection into 1 eye every 6 weeks for 48 weeks. The effectiveness of pegaptanib was realized as early as week 6 and continued through week 54. At week 54, 38% of patients receiving pegaptanib 0.3 mg were classified as legally blind versus 56% of those receiving the sham injection. Conclusions: Pegaptanib, a new inhibitor of ocular neovascularization, provides patients with an alternative to photodynamic therapy with verteporfin and offers a novel approach to future drug developments for AMD. Pegaptanib offers the advantage of not requiring photodynamic therapy in conjunction with drug delivery and may be a viable option for institutions where this service is not easily accessible. Results of clinical trials have shown that pegaptanib is effective in delaying progression of AMD.
Long QTc Interval and Torsade de Pointes Caused by Fluconazole
Authors: Pham C Phu , de Feiter Peter W , van der Kuy P Hugo M , van Mook Walther NKA 
Published: July 2006

Objective: To describe a patient who developed torsade de pointes while being treated with fluconazole. Case Summary: A 33-year-old woman with a 5 year history of systemic lupus erythematosus was admitted to the intensive care unit because of respiratory insufficiency due to Candida albicans pneumonia. Therapy with intravenous fluconazole 200 mg/day, with dose later adjusted according to her renal function, was started. Prolongation of the QTc interval and torsade de pointes occurred. Initially, domperidone, which had been initiated the day before fluconazole, was suspected as the possible cause and was discontinued; ultimately, both drugs were discontinued. However, torsade de pointes recurred several weeks later when the patient was treated with fluconazole for a second time and disappeared again on withdrawal of the drug. According to the Naranjo probability scale, this adverse reaction was highly probable. Discussion: The risk of torsade de pointes does not correlate in a linear fashion with prolongation of the QTc interval, but an interval beyond 500 msec is considered a significant risk factor. Given that both fluconazole and domperidone are metabolized by the cytochrome P450 system, they may intensify each other's proarrhythmic effects, particularly in patients with concurrent renal dysfunction. These risks are of particular concern in patients whose baseline QTc interval is prolonged for any reason. Conclusions: From the case history, as well as use of the Naranjo scale, we concluded that fluconazole was the highly probable cause of the development of torsade de pointes in our patient.