bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of a Novel Quinoxaline-Substituted vic-Dioxime and Its Complexes Containing Bis(12-Diazacrown-4) Derivatives
Authors: Bilgin Ahmet , Ertem Beytullah , Gök Yasar 
Published: August 2007

Abstract
A new quinoxaline-substituted vicinal dioxime ligand containing bis(12-diazacrown-4) units (H2L) was synthesized by the reaction of cyanogen di-N-oxide with compound 4. Mononuclear NiII and CuII complexes with a metal:ligand ratio of 1:2 for H2L and a trinuclear CuII complex were also synthesized. The mononuclear CuII species coordinated to two CuII ions through the deprotonated oximate oxygens to yield a trinuclear structure cis-bridged by the oximate groups, with 1,10-phenanthroline as an end-cap ligand. The mononuclear CoIII complex of H2L was isolated with pyridine and chlorine as axial ligands. In addition, a CoIII complex containing the BF2+ bridge macrocycle was synthesized using a precursor hydrogen-bridged CoIII complex via a template effect. The extraction abilities of 1, 3, and 11 were also evaluated in 1,2-dichloroethane by using several alkali (Li+, Na+, K+, and Cs+) and transition-metal picrates, such as Ag+, Pb2+, Cd2+, Cu2+, and Zn2+. Structures of the ligands and metal complexes were solved by elemental analyses, 1H and 13C NMR, FT-IR, UV–vis, and mass spectra.
Synthesis and Properties of 5-(3-Pyridyl)porphyrinatoruthenium(II) Tetramers
Authors: Funatsu Kenji , Yasuda Naomi , Ichimura Akio , Santo Ryoko , Sasaki Yoichi , Imamura Taira 
Published: August 2007

Abstract
5-(3-Pyridyl)porphyrinatoruthenium(II) tetramers, [{Ru(3-PyT3porph)(CO)}4] (1), [{Ru(3-PytB3porph)(CO)}4] (2), [{Ru(3-PyHex3porph)(CO)}4] (3), and [{Ru(3-PytB3porph)(py)}4] (4) were prepared. The structures of the isolated tetramers were determined to be rhombic shaped with two chemically nonequivalent porphyrinatoruthenium(II) subunits by 1H NMR, IR, and ESI-MS measurements. The tetramers were stable in benzene at 70 °C. However, the tetramers reacted with a large excess of pyridine to give two geometrical isomers of porphyrinatoruthenium(II) in dichloromethane at room temperature as observed by 1H NMR spectrometry. UV–vis spectra of the tetramers showed splitting or broadening of the Soret band due to excitonic interactions. Stepwise oxidations of the porphyrin rings or the ruthenium ions in the cyclic tetramer skeleton were observed in cyclic voltammograms.
Enantioselectivity in Electron-Transfer Reactions between Cytochrome c and (S)-/(R)-Ruthenium Complexes. Non-Polar Interaction in a Molecular Recognition Process
Authors: Kato Takashi , Takahashi Isao , Kumita Hideyuki , Ozawa Tomohiro , Funahashi Yasuhiro , Jitsukawa Koichiro , Masuda Hideki 
Published: August 2007

Abstract
Redox reactions between horse heart cytochrome c and optically active Ru complexes were kinetically studied. The kinetic parameters for the oxidation of ferrocytochrome c with RuIII complexes indicated an apparent enantioselectivity, which clearly shows that exact molecular recognition is achieved through non-polar interactions rather than electrostatic ones.
Studies on Ring-Closing Metathesis for the Formation of the 11-Membered Ring System of Daphnezomine C
Authors: Tanabe Kazuhisa , Fujie Ayako , Ohmori Naoki , Hiraga Yoshikazu , Kojima Satoshi , Ohkata Katsuo 
Published: August 2007

Abstract
For the purpose of synthesizing daphnezomine C, model systems were examined to see if the ring-closing metathesis (RCM) reaction could be applied to prepare an 11-membered ring system bearing a tri-substituted alkene. As a result, it was found that the connectivity pattern of the tethers bearing the reacting alkene moieties was crucial. Thus, whereas a system involving a single 1,3- or 1,4-disubstituted cyclohexane derivative did not give RCM products, a flexible system without any rings between the two terminal alkenes gave the cyclic product with a yield of up to 65% using the second generation Grubbs catalyst.
Synthesis of Perfluorinated Ketones by Utilizing Liquid-Phase Direct Fluorination
Authors: Okazoe Takashi , Watanabe Kunio , Itoh Masahiro , Shirakawa Daisuke , Takagi Hirokazu , Kawahara Kengo , Tatematsu Shin 
Published: August 2007

Abstract
A new synthetic procedure for the preparation of perfluorinated ketones from nonfluorinated sec-alcohols was developed. A key step in the synthetic route was a liquid-phase direct fluorination reaction with elemental fluorine. Direct fluorination of a partially fluorinated ester, which was prepared from a nonfluorinated sec-alcohols and a perfluorinated acyl fluoride, followed by thermal elimination, gave a perfluorinated ketone and the starting perfluorinated acyl fluoride, which could be recycled. Application to the synthesis of a precursor polyfluoroketone for fluoropolymer resists for 157 nm microlithography was also established.
Efficient Way to Attach Organosilyl Groups in the Interlayer Space of Layered Solids
Authors: Ide Yusuke , Ogawa Makoto 
Published: August 2007

Abstract
An efficient method to immobilize silane-coupling reagents on the interlayer space of a layered silicate, magadiite (Na2Si14O29·nH2O), is reported. The silylation was conducted by concentrating a mixture containing the pre-synthesized dodecyltrimethylammonium-exchanged magadiite and a stoichiometric amount (molar ratio of silane-coupling reagent/Si14O29 unit of magadiite = 2.0) of (3-mercaptopropyl)trimethoxysilane. The resulting silylated derivative possessed basal spacing and had a composition comparable to those of the silylated derivative, prepared by using a previous silylation method, which involves dodecyltrimethylammonium-exchanged form with a much larger amount (molar ratio of silane-coupling reagent/Si14O29 unit of magadiite = 57) of the silane-coupling reagent. When the present method was employed, the surface coverage with (3-mercaptopropyl)silyl groups on the layer surface directly correlated to the amount of the silane-coupling reagent.
Celiac Disease: Are Endomysial Antibody Test Results Being Used Appropriately?
Authors: McGowan Kelly E , Lyon Martha E , Loken Steven D , Butzner J Decker 
Published: August 2007

Abstract
Background: The aim of this study was to retrospectively examine how positive IgA-endomysial antibody (EMA) test results for celiac disease were being interpreted and acted on by physicians in the Calgary Health Region.
Methods: We reviewed consecutive EMA test results, with or without a serum IgA, obtained during a 17-month period. Seropositive tests were cross-referenced to the surgical database to determine the number of patients who underwent intestinal biopsy and the results of the biopsy. We sent questionnaires to the ordering physicians of positive tests with no record of intestinal biopsy.
Results: Among 11 716 EMA tests in 9533 patients, 349 results were positive in 313 patients (3%). Intestinal biopsies were performed in 218 (70%) of the seropositive patients; 194 of them were diagnostic of celiac disease. Celiac disease was also found in 10 EMA-negative patients. Of the 109 positive tests performed in 95 patients with no subsequent biopsy, 28 had appropriate indications to not perform a biopsy; the most common reason being that the test had been ordered to follow up on a previous biopsy-proven diagnosis of celiac disease (n = 21). For 33 other positive test results without a subsequent biopsy, management appeared to be inappropriate, most commonly (n = 21) because of a recommendation to follow a gluten-free diet despite lack of a tissue diagnosis of celiac disease. For the remaining 48 positive EMA results, administrative issues prevented evaluation (n = 19), the patients refused further evaluation (n = 11), or physician surveys were not returned (n = 18).
Conclusions: Celiac disease affected 2% of patients, with a similar prevalence in male and female patients. Most positive EMA tests (77%) were appropriately managed by physicians. Beginning a gluten-free diet without biopsy or failing to follow up on a positive EMA test remain common errors of management.
Seasonal variations in the composition and gel quality of agar fromGracilaria edulisin the Philippines
Authors: Romero Jumelita B. , Montaño Marco Nemesio E. , Merca Florinia E. , Villanueva Ronald D. , Liao Ming-Long , Bacic Antony 
Published: August 2007

AbstractAgar fromGracilaria eduliscollected in the Philippines is composed primarily of a repeating disaccharide unit of 4-linked 3,6-anhydro-α-L-galactopyranose (LA) and 3-linked 6-O-methyl-β-D-galactopyranose (G6M). Chemical and spectroscopic analyses further revealed partial (19–27 mol %) methylation at O-2 of the LA residues. Sulfate was attached to O-4 of G6M and/or G,with approximately 20% of these residues bearing the substituent. No pyruvate substituent was detected. A seasonal assessment of the composition, rheological and physical properties ofGracilaria edulisagar was undertaken. Constituent sugar analysis revealed a variable degree of methylation (80–91 mol % on O-6 of the G and 19–27 mol % on O-2 of the LA residues); the highest amounts of mono-O-methylated residues (G6M and LA2M) were found in the samples collected in the dry season while the lowest was obtained during the rainy season. The sample collected during the onset of the rainy season contained the lowest amount of sulfate (2.3%) while the cold season sample contained the highest sulfate content (3.2%). Seaweed samples collected during the onset of the rainy season exhibited the highest agar yield, gel strength, deformation, cohesiveness, and melting temperature.Gracilaria edulisagar possesses gel characteristics useful in the food industry.
A New Numerical Analysis for Rectangular Tensile Sheet with Single Edge Crack by Boundary Elements
Authors: Yan Xiangqiao 
Published: August 2007

Abstract
By using the hybrid displacement discontinuity method (a boundary element method) proposed recently by the author, in this note a new numerical analysis is presented for the stress intensity factors (SIFs) of rectangular tensile sheet with single edge crack. The new numerical results can reveal the effect of the boundaries parallel to the crack on the SIFs.
Spent fuel UO2 matrix alteration in aqueous media under oxidizing conditions
Authors: Jegou Christophe , Muzeau B. , Broudic V. , Roudil Danièle , Deschanels X. 
Published: August 2007

The effects of αβγ radiolysis of water on oxidation and dissolution of the UO2 matrix of spent fuel were investigated in aerated media. The prospect of long-term interim storage of spent fuel assemblies in pools requires prior examination of an incident scenario in which a cladding failure could eventually lead to contact between water and the fuel. Radiolytic oxidation of the matrix together with the formation of secondary phases subject to volume expansion could then no longer be disregarded, and could enhance the degradation of the failed rod.
To determine the amplitude of the alteration various spent fuel leaching experiments conducted at different degrees of oxidizing conditions and of accessibility of species at the reaction interface are discussed. This work is based on modeling the radiolysis processes and on various possible interpretations of leaching test results. Properly interpreting these results implies full knowledge of the fuel sample history, and the development of a rigorous experimental approach to eliminate any artifacts (problems due to the residual inventory at the grain boundaries, or to inaccurate estimates of the actual surface area). The results indicate that despite highly variable oxidizing conditions (presence of an external γ irradiation source, addition of H2O2, aerated water) the spent fuel matrix alteration determined from the release of tracer elements such as Cs and Sr is always the same. Conversely, allowing for the alteration conditions (no solution renewal and no complexants), the uranium concentrations in solution do indeed depend on the oxidizing conditions as does the nature of the secondary phases liable to precipitate.
Empore™ strontium rad disks: validation procedure for strontium-90 analysis in radioactive wastes
Authors: Heynen F. , Minne E. , Hallez Ir. S. 
Published: August 2007

90Sr determination in radioactive waste is currently supported by Eichrom™ Sr-spec concentration columns. This research was aimed at finding a faster and easier technique, leading to identical results. It was chosen to make use of the 3M Empore™ membranes.It was deliberatly decided not to follow RP515 procedure (US Department of Energy).90Y will be counted by liquid scintillation after EDTA elution. Official accreditation needs to verify every validation test.Information concerning the specificity of the membranes has been reviewed. Uncertainty calculation of the activity, as well as the detection limit, are described. The enlarged uncertainty (k= 2) reaches to about 10% for a90Sr activity of 2Bq/L. The detection limit obtained with this procedure reaches to about 50mBq/L for a sample of 0.5L and a 10h counting time. A selectivity test detects the possibility of89Sr presence which could disturb the90Sr determination. Robustness of the method is mainly assured by the use of a tracer (85Sr as in RP515). The analysis of non aqueous biological samples has been carried out for accuracy. It required an adaptation of the preparation process. Linearity was tested on a range from 0 to 18.5Bq/L90Sr. The results of 38 routine samples obtained by the Empore™ Sr Rad Disks were compared with those obtained by the Eichrom Sr-spec columns protocol. This comparison showed a good correlation between the two techniques.
Advanced fractionation technology for the oleochemical industry
Authors: Faessler Peter , Kolmetz Karl , Seang Kek Wan , Lee Siang Hua 
Published: August 2007

AbstractSteadily increasing requirements on fractionation demands in the oleochemical industry require advanced separation technology. Today, often a distillation column has not only to process several different feeds, but also be able to produce two different products simultaneously. Divided wall columns have been proposed and used in the chemical industry, but there are, presently, few applications of divided wall columns in the oleochemical sector. The main reason prohibiting their use might be in the limited familiarity, higher requirements on operation, potential corrosion problems and last but not least, limited flexibility.Fractionation columns with added side stripper are a well‐proven way to satisfy increased demand of separation duties. The availability of second‐generation structured packing increases the efficiency and reduces pressure drops while making it possible to increase capacity and/or product purities. A lower pressure drop has a positive impact on the separation itself. Combining these effects with an increase in capacity will result in a synergy effect on the separation performance.The newly developed BXPlus structured packing is a powerful tool for advanced Glycerin separation, combining good wettability resulting in high efficiency with low‐pressure drop. New columns can be designed much more compactly. Revamps will improve both capacity and/or purity. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
The energy challenge of direct contact membrane distillation in low temperature concentration
Authors: Bui V. A. , Nguyen M. H. , Muller J. 
Published: August 2007

AbstractDirect contact membrane distillation (DCMD) was operated at low temperatures from 25 to 40 °C to suit the purpose of thermally concentrating sensitive liquid foods, especially fruit juices to high solid content concentrate with most of the quality attributes preserved.A lab scale DCMD unit has been set up at the Centre for Plant and Food Science, University of Western Sydney. Hollow fibre modules (HFM) using five types of fibres of polyvinylidene fluoride (PVDF) and Halar material, with mass transfer areas ranging from 281 to 573 cm2 were employed. Experiments for concentration of glucose solutions from 30 to 60% (w/w) were carried out. Results indicated that not only the operating conditions were important, but also the membrane properties. It was found that Halar fibres were performing 2–3 times better than PVDF fibres in term of removing water from the feed, and 3–4 times better in term of energy saving. Results also showed that an increase of the feed inlet temperature from 25 to 40 °C improved the mass flux up to 6 times and energy efficiency (EE) up to 2.5 times depending on the feed concentration.With flux up to 2.88 kg m−2 h−1 for PVDF and 5.83 kg m−2 h−1 for Halar fibres when concentrating 30% glucose solution at 40 °C, DCMD appeared to be an attractive concentration technique, when product quality is the priority. However, with EE from as low as 2.1–14.9%, PVDF fibres employed in the study seemed not to be very suitable for DCMD liquid food concentration under low temperature condition. DCMD in Halar fibres with EE up to 45.6% still encounters the challenge of energy and could only be cost competitive to osmotic distillation and evaporative concentration when cheaper energy sources or heat recovery measures are employed. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
gem‐Dihalocyclopropanes as Building Blocks in Natural‐Product Synthesis: Enantioselective Total Syntheses of ent‐Erythramine and 3‐epi‐Erythramine
Authors: Stanislawski Pauline C. , Willis Anthony C. , Banwell Martin G. 
Published: August 2007

Abstractent‐Erythramine ((−)‐1), the enantiomer of the alkaloid erythramine, was prepared in 15 steps from known compounds. The first of three pivotal bond‐forming steps in the synthesis was a Suzuki–Miyaura cross‐coupling reaction of the starting materials to give a bis‐silyl ether. The second involved silver(I)‐induced electrocyclic ring opening of the gem‐dichlorocyclopropane formed in the next step and trapping of the ensuing π‐allyl cation by the tethered nitrogen atom to give, following cleavage of the allyloxycarbonyl protecting group, an approximately 5:6 mixture of the chromatographically separable diastereoisomeric spirocyclic products. In the third critical bond‐forming reaction, the iodide formed from one of the diastereoisomers underwent a radical‐addition/elimination reaction sequence that led to (−)‐1 in 89 % yield. The application of the same sequence of transformations to the other diastereoisomer afforded 3‐epi‐(+)‐erythramine (3‐epi‐(+)‐1).
Dosimetric evaluation and comparison of different RF exposure apparatuses used in human volunteer studies
Authors: Boutry Clémentine M. , Kuehn Sven , Achermann Peter , Romann Albert , Keshvari Jafar , Kuster Niels 
Published: August 2007

AbstractThe aim of this study was to provide the information necessary to enable the comparison of exposure conditions in different human volunteer studies published by the research groups at the Universities of Turku, Swinburne, and Zurich. The latter applied a setup optimized for human volunteer studies in the context of risk assessment while the first two applied a modified commercial mobile phone for which detailed dosimetric data were lacking. While the Zurich Setup exposed the entire cortex of the target hemisphere, the other two setups resulted in only very localized exposure of the upper cheek, and concentrated on a limited area of the middle temporal gyrus just above the ear. The resulting peak spatial SAR averaged over 1 g of the cortex was 0.19 W/kg of the Swinburne Setup, and 0.31 W/kg for the Turku Setup, compared to 1 W/kg for the Zurich Setup. The average exposure of the thalamus was 5% and 9% of the Zurich Setup results for the Swinburne and Turku Setups, respectively. In general, the phone‐based setup results in only reasonably defined exposures in a very limited area around the maximum exposure; the exposure of the rest of the cortex was low, and may vary greatly as a function of the setup, position, and local anatomy. The analysis confirms the need for a carefully designed exposure setup that exposes the relevant brain areas to a well‐defined level in human volunteer studies, and shows that studies can only be properly compared and replicated if sufficiently detailed dosimetric information is available. Bioelectromagnetics 29:11–19, 2008. © 2007 Wiley‐Liss, Inc.
Lack of promotion effects of 50 Hz magnetic fields on 7,12‐dimethylbenz(a)anthracene‐induced malignant lymphoma/lymphatic leukemia in mice
Authors: Negishi Tadashi , Imai Setsuo , Shibuya Kazumoto , Nishimura Izumi , Shigemitsu Tsukasa 
Published: August 2007

AbstractNew‐born CD‐1 mice were initiated with a single subcutaneous injection of 60 µg 7,12‐dimethylbenz(a)anthracene (DMBA) within 24 h after birth. After weaning, the mice were randomly divided into five groups of 100, 50 males and 50 females each. One group served as a cage control. The other four groups of mice were exposed to either 0 (sham‐exposed), 7, 70, or 350 µT(rms) circularly polarized 50 Hz magnetic fields (MFs) for 22 h/day, 7 days/week for 30 weeks. Animals were observed daily and the development of malignant lymphoma/lymphatic leukemia was examined histopathologically. The experiment was conducted twice. There was no observed sexual difference in the cumulative proportions of mice with malignant lymphoma/lymphatic leukemia and a 3‐way analysis of deviance using the Cox regression model revealed no interactions between experiment, sex, or group. The cumulative proportions of mice with malignant lymphoma/lymphatic leukemia in the MF‐exposed groups were not significantly higher than those in the sham‐exposed group of each sex in individual experiments and in males and females combined in each experiment, and in all the animals from the two experiments combined. These data provide no evidence to support the hypothesis that power frequency MFs is a significant risk factor for hematopoietic neoplasia. Bioelectromagnetics 29:29–38, 2008. © 2007 Wiley‐Liss, Inc.
Mobile phone base station radiation does not affect neoplastic transformation in BALB/3T3 cells
Authors: Hirose H. , Suhara T. , Kaji N. , Sakuma N. , Sekijima M. , Nojima T. , Miyakoshi J. 
Published: August 2007

AbstractA large‐scale in vitro study focusing on low‐level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT‐2000) cellular system was conducted to test the hypothesis that modulated RF fields affect malignant transformation or other cellular stress responses. Our group previously reported that DNA strand breaks were not induced in human cells exposed to 2.1425 GHz Wideband Code Division Multiple Access (W‐CDMA) radiation up to 800 mW/kg from mobile radio base stations employing the IMT‐2000 cellular system. In the current study, BALB/3T3 cells were continuously exposed to 2.1425 GHz W‐CDMA RF fields at specific absorption rates (SARs) of 80 and 800 mW/kg for 6 weeks and malignant cell transformation was assessed. In addition, 3‐methylcholanthrene (MCA)‐treated cells were exposed to RF fields in a similar fashion, to assess for effects on tumor promotion. Finally, the effect of RF fields on tumor co‐promotion was assessed in BALB/3T3 cells initiated with MCA and co‐exposed to 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA). At the end of the incubation period, transformation dishes were fixed, stained with Giemsa, and scored for morphologically transformed foci. No significant differences in transformation frequency were observed between the test groups exposed to RF signals and the sham‐exposed negative controls in the non‐, MCA‐, or MCA plus TPA‐treated cells. Our studies found no evidence to support the hypothesis that RF fields may affect malignant transformation. Our results suggest that exposure to low‐level RF radiation of up to 800 mW/kg does not induce cell transformation, which causes tumor formation. Bioelectromagnetics 29:55–64, 2008. © 2007 Wiley‐Liss, Inc.