bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Studies on Hydrogen Bonding Interactions between Peptide Units
Authors: Aida Misako 
Published: August 2006

Abstract
The hydrogen bonding interaction energies between peptide units were calculated using the ab initio MO method with the STO-3G, 7,3/2,1 and 6-31G basis sets and a correction of the basis set superposition errors (BSSE). The same systems were also investigated using an ab initio potential which has recently been developed and the AMBER potential, which is widely used. The energy profiles calculated using the ab initio potential are similar to those calculated using the 6-31G basis set. The distance and angle dependencies of the hydrogen bonding interactions are well represented by the ab initio potential. In contrast, they are not reproduced by the AMBER potential.
Excitation Functions of the Slow and Fast Groups of the Excited Hydrogen Atom Produced in e–H2 Collisions
Authors: Ogawa Teiichiro , Jinbou Youichi , Yonekura Nobuaki , Furuya Kenji , Nakashima Keiji 
Published: August 2006

Abstract
Excitation functions of the fast group of H*(n = 3,4) show two thresholds at 22—23 and about 27 eV. Their comparison indicates that the dissociation process through the 1Σu+(2pσu)(nlσg) states are relatively more important for H*(n = 4).
Energy Transfer between Anthracene Chromophore and Sexithiophene in Langmuir–Blodgett Assemblies
Authors: Dutta Ashim Kumar , Pal Amlan Jyoti , Misra Tridibendra Narayan 
Published: August 2006

Abstract
Excellent Langmuir–Blodgett (LB) films of 9,10-diphenylanthracene (DPA) and α,α-linked sexithiophene (6T) with arachidic acid (AA) can be formed on water subphase and can be transferred on to quartz substrates. Electronic absorption and emission spectra of these films have been studied and compared with those in solution. Results suggest formation of aggregates of DPA and 6T in LB films. 6T has been used as a quencher for the DPA donor fluorescence. It is shown that the efficiency of energy transfer from the donor to the acceptor decreases with the quadratic power of the distance separating them. Such quadratic dependence confirms that the donor excitation is delocalized.
Coordination of Some Simple Molecules onto W(CO)5 in the Gas Phase
Authors: Jyo-o Motohiro , Takeda Hideki , Omiya Kenji , Ishikawa Yo-ichi , Arai Shigeyoshi 
Published: August 2006

Abstract
In the gas phase at room temperature, the coordination process of NH3, C2H4, CF4, SF6, and Xe onto “naked” W(CO)5, selectively prepared by pulsed 355-nm laser photolysis of W(CO)6, was investigated by laser-based time-resolved infrared absorption spectroscopy. W(CO)5 reacted with these reactant gases, except for CF 4 and SF6, to make a simple coordination complex, W(CO)5(L), where L is NH3, C2H4, or Xe. The bimolecular rate constants for these reactions were (5.6 ± 0.6) × 106 Torr−1 s−1 for W(CO)5 + NH3, (2.8 ± 0.5) × 106 Torr−1 s−1 for W(CO)5 + C2H4, and (1.0 ± 0.3) × 105 Torr−1 s−1 for W(CO)5 + Xe. W(CO)5Xe was unstable owing to its weak interaction with the coordinatively unsaturated tungsten center, the unimolecular decomposition rate of which was about 1.0 × 105 s−1, but W(CO)5(NH3) and W(CO)5(η2-C2H4) were stable under our experimental conditions. The band shifts of C–O stretching modes observed in the coordination of NH3 as a typical σ-donor, C2H4 as a typical π-acceptor, and Xe as a weak σ-donor could interpreted by MO considerations.
Column Chromatographic Separation of Uranium(VI) with Poly(dibenzo-18-crown-6) from Hydrochloric Acid Medium
Authors: Mohite Baburao Shankarrao , Patil Jaykumar Malgonda , Zambare Dnyandeo Namdeo , Mali Umesh Ganpatrao 
Published: August 2006

Abstract
A very simple method has been developed for the column chromatographic separation of uranium(VI) using poly(dibenzo-18-crown-6). The adsorption studies were carried out from hydrochioric acid medium in the concentration range of 0.5—10.0 mol dm−3. The adsorption of uranium(VI) started from 3.0 mol dm−3 hydrochloric acid and was quantitative from 5.5—10.0 mol dm−3 hydrochloric acid. Various eluting agents such as hydrobromic acid, perchloric acid, sulfuric acid, acetic acid were used for the elution of uranium(VI). The capacity of poly(dibenzo-18-crown-6) for uranium(VI) was found to be 2.5 mmol g−1 of crown polymer. Uranium(VI) was separated from large number of elements from the binary as well as from multicomponent mixtures. The method was applied to the analysis of uranium from real samples.
General Synthesis, Spectroscopic Properties, and Dipole Moments of 2-Substituted Tropothiones
Authors: Machiguchi Takahisa , Hasegawa Toshio , Kano Yuichi 
Published: August 2006

Abstract
Several 2-substituted tropothiones (2,4,6-cycloheptatriene-1-thiones) having an electron-donating group (Me, Ph, NH2, NHMe, OH, OMe, or SMe) were synthesized by direct sulfurization from the corresponding tropones in a one-pot reaction. In contrast to the instability of the parent tropothione (1a), most of these 2-substituted derivatives were insensitive to air and were thermally stable compounds which can be handled at room temperature. These tropothione derivatives were characterized by spectroscopic and dipole moment measurements. The IR spectra showed ν(C=S) vibrations at around 1100—1040 cm−1. The UV-vis spectra displayed three π–π* transitions accompanied by n–π* transitions. The 400-MHz 1H NMR spectra of the thiones showed that only protons at the 7 position resonate well-separated downfield from the other ring protons due to the strong C=S anisotropy. In the 13C NMR (100.6 MHz) spectra, the C=S carbon signals appeared at &lt; δ = 183 and the other ring carbons resonated at δ = 154—112. Variable-temperature 13C as well as 14N NMR spectroscopic studies clarified that 2-amino- and 2-(methylamino)tropothiones exist as an equilibrium mixture of the thione and enethiol structures in an approximate ratio of 64 : 36. This is different from the results of a previous investigation showing that the structures exist as the thione form exclusively. Dipole moments of some derivatives of 1a were measured and compared with those of the corresponding tropones. These tropothione derivatives obtained were more ionic than both the parent compound 1a and the corresponding tropones.
Reactivities of Stable Rotamers. XXXII. Chlorodecarboxylation of 3-(1,4-Dimethyl-9-triptycyl)-3-methylbutanoic Acid Rotamers
Authors: Oki Michinori , Taguchi Yasushi , Okamoto Toshiyuki , Miyasaka Tsutomu , Hamada Koji , Toyota Shinji , Yonemoto Katsumi , Yamamoto Gaku 
Published: August 2006

Abstract
Rotational isomers of the title carboxylic acid were treated with lead(IV) acetate in the presence of lithium chloride or benzyltriethylammonium chloride in benzene. The ap-isomer afforded a chloride, which was expected from normal chlorodecarboxylation, in addition to a cyclized compound, which was produced by radical addition to a near-by benzene ring. By contrast, the sc-isomer afforded no normal chloride, but a benzylic chloride, which was formed by hydrogen transfer to the radical site in the 9-substituent from the benzylic position, was the main product. In addition, an acetonyl ester of the original sc-carboxylic acid and a small amount each of 1-acetoxymethyl compound and an olefin were obtained. Possible mechanisms of formation of these compounds are discussed on the ground of the stability of the benzylic radical and participation of a methyl group.
Conjugate Addition of α-(Trialkylstannyl)alkyl Groups to α,β-Enones: Preparation of γ-Stannyl Ketones
Authors: Sato Tadashi , Tachibana Kazutaka , Kawase Akira , Hirose Tomokazu 
Published: August 2006

Abstract
The title reaction was examined under various conditions. The corresponding cuprates underwent 1,4-addition satisfactorily to afford γ-stannyl ketones.
Fulvestrant: Pharmacologic Profile Versus Existing Endocrine Agents for the Treatment of Breast Cancer
Authors: Buzdar Aman U , Robertson John FR 
Published: August 2006

Objective: To compare the pharmacologic profile of fulvestrant with that of tamoxifen and the aromatase inhibitors with respect to the choice of treatment for advanced breast cancer (ABC). Data Sources: Principal literature and review articles were obtained from MEDLINE (1991–March 2006). Key search terms included fulvestrant, tamoxifen, aromatase inhibitors, pharmacology, and breast cancer. Further data sources were identified from the bibliographies of selected articles. Study Selection and Data Extraction: English-language preclinical and clinical research and review articles reporting pharmacologic and safety data for fulvestrant, tamoxifen, and the aromatase inhibitors were evaluated to identify relevant information. Randomized clinical trial data were preferred over preclinical or Phase I and II trial data. Data Synthesis: A total of 52 clinical papers (including 10 reviews) and 17 clinical abstracts were evaluated reporting results from controlled Phase I–III studies and pilot studies. Eleven preclinical papers (including 2 reviews) and 6 preclinical abstracts were also included. Fulvestrant has little effect on sex hormone endocrinology, bone metabolism, and lipid biochemistry and appears unlikely to be the subject or cause of CYP3A4-mediated drug interactions. Tamoxifen has a protective effect on bone (due to its partial estrogen agonist activity) and reduces plasma low-density lipoprotein cholesterol but increases triglyceride levels. The aromatase inhibitors have variable effects on lipid profiles and sex hormone endocrinology but have detrimental effects on bone due to inhibition of estrogen synthesis. Drug interactions have been noted between tamoxifen and anticoagulants and tamoxifen and aromatase inhibitors, which may be due to CYP-mediated mechanisms. Conclusions: Fulvestrant appears to have little effect on sex hormone endocrinology, bone metabolism, and lipid biochemistry and is unlikely to be subject to or the cause of CYP3A4-mediated drug–drug interactions. As such, fulvestrant represents a valuable new endocrine therapy for the treatment of ABC and broadens the options available to clinicians in the treatment of this disease.
Physicians’ Perceived Knowledge of and Responsibility for Managing Patients’ Out-of-Pocket Costs for Prescription Drugs
Authors: Shrank William H , Asch Steven M , Joseph George J , Young Henry N , Ettner Susan L , Kholodenko Yelena , Glassman Peter , Kravitz Richard L 
Published: August 2006

Background: Most insurers in the US have implemented incentive-based formularies that rely on out-of-pocket costs to influence prescription drug utilization. Medicare Part D plans have broadly adopted such benefit designs. Objective: To evaluate physicians’ perceptions of their knowledge of formularies and out-of-pocket costs, factors that influence knowledge of costs, physicians’ perceived responsibility for helping patients manage their out-of-pocket costs for prescription drugs, and physicians’ perceptions of the role of pharmacists in managing these costs. Methods: A multiple-choice survey was mailed to a random sample of 1200 physician members of the California Medical Association; a phone survey of nonresponders was then conducted. Results: Of 1027 surveys delivered to correct addresses, 509 (49.6%) responses were received. Thirty-three percent of physicians reported that they were usually or always aware of patients’ formularies and 20% were usually or always aware of patients’ out-of-pocket costs for medications. Surgeons, emergency department physicians, and physicians that prescribe from more formularies than other physicians are less likely to be aware of patients’ out-of-pocket costs, while physicians in large practices and those who use computers to prescribe are more aware. While 91% of physicians agreed that it is important that patients’ out-of-pocket costs be managed, 40% somewhat or strongly agreed that it is their responsibility to help. Sixty-five percent of physicians believed that it is the responsibility of the pharmacist to be familiar with patients’ out-of-pocket costs. Conclusions: Physicians often lack the knowledge to assist patients in the management of their out-of-pocket costs for prescription drugs and they depend on pharmacists to help patients manage those costs. Computer order entry and resources available in large physician organizations improve physicians’ awareness of out-of-pocket costs when prescribing.
Which Pharmacists Contribute to High-Level Pharmacotherapy Audit Meetings with General Practitioners?
Authors: Florentinus Stefan R , Hulten Rolf van , Kramer Marjolein , Dijk Liset van , Heerdink Eibert R , Leufkens Hubert GM , Groenewegen Peter P 
Published: August 2006

Background: In the Netherlands, community pharmacists and general practitioners (GPs) collaborate in pharmacotherapy audit meetings (PTAMs) to optimize pharmacotherapy. Objective: To identify associations between the quality level of PTAMs and characteristics of pharmacists. Methods: We used a cross-sectional questionnaire design in a Dutch general practice and community pharmacy setting to estimate the contribution of pharmacists to the quality level of PTAMs. The questionnaire was sent to 123 community pharmacies working closely with 104 GP practices. The outcome variable was the quality level of PTAMs. The questionnaire provided information on 4 topics that were used as independent variables: characteristics of the PTAMs, provision of pharmacotherapy activities, characteristics of the pharmacists, and characteristics of the pharmacies. Results: In total, 109 (88.6%) pharmacists completed the questionnaire, with 103 participating in 62 different PTAMs. Seventeen pharmacists participated in level 1 PTAMs (lowest level), 57 in level 2, 21 in level 3, and 8 in PTAMs at the highest level. The multinomial logistic regression identified only one significant association: pharmacists who participated in the highest quality level reported that they undertake initiatives in PTAMs (OR 2.98; 95% CI 1.07 to 8.26) more frequently compared with pharmacists participating on the lowest level. Conclusions: In light of existing evidence, the role of pharmacists in PTAMs seems to be important. Pharmacists should create a distinct profile of their expertise, allowing them to professionalize PTAMs by undertaking more initiatives. PTAMs offer pharmacists a great opportunity to become integral members of the prescribing process.
Direct investigation of the structural properties of tension wood cellulose microfibrils using microbeam X-ray fibre diffraction
Authors: Müller Martin , Burghammer Manfred , Sugiyama Junji 
Published: August 2006

Abstract
Single tension-wood fibres from poplar were investigated using a synchrotron radiation X-ray microbeam. The resulting diffraction patterns are highly resolved (smallest d-spacing 0.11 nm). In the gelatinous layer, cellulose microfibrils of high perfection are found in almost ideal parallel alignment. Their cross-section is approximately four-fold greater than that of microfibrils in the S2 layer of the same wood cell. The results are discussed in terms of the influence of encrusting cell wall polymers and cellulose biosynthesis on the structure of wood cellulose microfibrils. In temperature-dependent experiments, the low-temperature thermal expansion coefficients of crystalline cellulose were determined.
Synthesis of plantamajoside, a bioactive dihydroxyphenylethyl glycoside from Plantago major L.
Authors: Kawada Toshinari , Yoneda Yuko , Asano Ryuji , Kan-no Ippei , Schmid Walther 
Published: August 2006

Abstract
The first total synthesis of plantamajoside (1), 2-(3′,4′-dihydroxylphenyl)ethyl-4-O-caffeoyl-3-O-(β-D-glucopyranosyl)-β-D-glucopyranoside, which is one of the dihydroxyphenylethyl glycosides (caffeic acid sugar esters), is described. Key intermediate 2, 2-[3′,4′-bis(O-benzyl)phenyl]ethyl 2,6-di-O-acetyl-4-O-[3′,4′-bis(O-benzyl)caffeoyl]-β-D-glucopyranoside was glycosylated with trichloroacetoimidoyl 2,3,4,6-tetra-O-acetyl-α-D-glycopyranoside (3) to afford plantamajoside derivative 4a, 2-[3′,4′-bis(O-benzyl)phenyl]ethyl 2,6-di-O-acetyl-4-O-[3′,4′-bis(O-benzyl)caffeoyl]-3-O-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-β-D-glucopyranoside, in 39% yield. Plantamajoside derivative 4a was successfully converted into the target compound, plantamajoside (1), through a series of de-protective procedures. 1H- and 13C nuclear magnetic resonance (NMR) spectral data of the synthesized plantamajoside (1) were identical to those of the natural compound.
Diffusion of sulfide into Southern pine (Pinus taeda L.) and sweetgum (Liquidambar styraciflua L.) particles and chips
Authors: Jacobson Aaron J. , Smith Gregory D. , Yang Rallming , Banerjee Sujit 
Published: August 2006

Abstract
Sulfide diffusion into wood has a rapid reversible component and a much slower irreversible component. During the initial reversible phase, sulfide is unable to diffuse into parts of the wood structure, probably because of charge exclusion. The diffusion of hydroxide and sulfide into saturated wood was imaged by immersing chips in white liquor, splitting them open and then imaging the hydroxide and sulfide profiles. Sulfide moves into the interior of the chip at a faster rate than hydroxide does because it is prevented from entering some of the pores and must move deeper into the chip to access dilution water.
Studies on the dehydrogenative polymerizations of monolignol β-glycosides. Part 2: Horseradish peroxidase-catalyzed dehydrogenative polymerization of isoconiferin
Authors: Tobimatsu Yuki , Takano Toshiyuki , Kamitakahara Hiroshi , Nakatsubo Fumiaki 
Published: August 2006

Abstract
Dehydrogenative polymerization of isoconiferin (IC; coniferyl alcohol γ-O-β-D-glucopyranoside) catalyzed by horseradish peroxidase (HRP) was carried out. The polymerization of IC proceeded in a homogeneous system, resulting in a water-soluble dehydrogenation polymer (IC-DHP). The degree of polymerization (DP) of IC-DHP was significantly higher than that of a standard dehydrogenative polymer (CA-DHP) obtained from coniferyl alcohol (CA) in a heterogeneous system. Under optimum conditions, the DP of IC-DHP was 44 (M
n=1.5×104), whereas that for CA-DHP was only 11 (M
n=3.0×103, as acetate). Spectroscopic analyses confirmed that IC-DHP has a lignin-like structure containing D-glucose moieties attached to the lignin side-chains. The D-glucose unit introduced into γ-O position of CA essentially influenced the water solubility and molecular mass of the resulting DHP.
The role of resol fortifiers in latex wood adhesives
Authors: López-Suevos Francisco , Frazier Charles E. 
Published: August 2006

Abstract
Static and dynamic rheological analyses using time/temperature equivalence were applied to freestanding poly(vinyl acetate-co-NMA) adhesive films and to wood-bonded films (composites), which were completely dry in all cases. Films and composites were prepared with two types of cross-linking: (1) cross-linking through AlCl3 catalysis of N-methylolacrylamide (NMA) comonomer; and (2) additional cross-linking using a resol phenolic (PF) additive, in addition to AlCl3 catalysis. Rheological experiments revealed that accelerated weathering (AW) significantly modified the mechanical response of films and composites lacking the PF additive. For samples lacking PF fortifier, AW caused a new thermal transition appearing as a major mechanical softening in the long time domain (creep master curves) or in the low-frequency region (dynamic master curves). This new transition correlated to a performance loss found with fracture testing in a previous publication. Here, the static and dynamic rheological data indicated that the AW-induced softening was a reversible transition. Differential scanning calorimetry analysis and the manipulation of physical aging effects demonstrated that the AW-induced softening was a glass transition. The calorimetric weakness and temperature of this transition indicated that it corresponds to the Tg of poly(vinyl alcohol) (PVOH), which is the emulsion polymerization interfacial agent. In contrast, all PF-formulated samples displayed only the base polymer Tg. Therefore, the PF additive prevented weathering effects that lead to PVOH softening. Atomic force and scanning electron microscopy provided visual evidence of the action of PF on PVOH at interparticle boundaries. We suggest that the PF fortifier enhances latex durability through the formation of hydrolytically stable PVOH cross-links at the interparticle boundaries.
Influence of soil humic acid and fulvic acid on sorption of thorium(IV) on MX-80 bentonite
Authors: Xu D. , Wang X. K. , Chen C. L. , Zhou X. , Tan X. L. 
Published: August 2006

SummaryTh(IV) is considered herein as a chemical analogue of other actinides (IV). Effect of pH, ionic strength and humic acid/fulvic acid concentrations on the sorption of thorium(IV) to MX-80 bentonite was studied by batch technique. The sorption isotherms were acquired by varying pH in the range of 0.5–12 and FA/HA concentration in the range of 2–20 mg/L. The results indicate that soil fulvic acid has higher carboxylic content than humic acid, and has stronger positive influence on the sorption of Th(IV) on bentonite at low pH values than humic acid. The increase of FA/HA concentration results in a slight increase of Th(IV) sorption on FA/HA coated bentonite. The results of no drastic effect of different addition sequences of FA/HA and Th(IV) to bentonite suspension on Th(IV) sorption in the ternary system HA/FA-Th(IV)-bentonite indicate that both the Th(IV)-HA/FA complexation and HA/FA-bentonite sorption do not affect the sorption of Th(IV) on HA/FA coated bentonite obviously. The samples were also measured by SEM method and the results show that the surface properties of different samples are different.
Separation of uranium(VI) from tri- and tetravalent elements in phosphoric acid solutions
Authors: Brandel V. , Clavier N. , Dacheux N. 
Published: August 2006

SummaryA new method of separation of uranyl ions from di-, tri- and tetravalent cations such as thorium, zirconium, cerium(IV) and/or lanthanides(III) involving phosphoric acid medium is described in this paper. The process is based on the difference of solubility between various phosphates: M2(PO4)2(HPO4)·H2O, M(HPO4)2·H2O, M(OH)PO4(where M is a tetravalent cation) or APO4·nH2O (where A is a trivalent cation) on the one hand, and the uranyl phosphate pentahydrate (UO2)3(PO4)2·5H2O, on the other hand. Taking into account the associated solubility constants, the conditions of separation were calculated then experimented for a mixture of Th4+, Ce4+(as a plutonium surrogate), Zr4+, La3+, Ba2+, Sr2+and UO22+. Tetravalent and trivalent cations phosphates were precipitated in 2 mol L−1nitric acid medium while uranyl ion and divalent cations remained in the solution. In a second step, (UO2)3(PO4)2·5H2O was precipitated at pH ≈ 1.5 and thereby separated from divalent cations present in the solution.