bluuebunny/crossref_metadata_2025 huggingface dataset:
Professionalism and the Match: A Pediatric Residency Program's Postinterview No-Call Policy and Its Impact on Applicants
Authors: Opel Douglas , Shugerman Richard , McPhillips Heather , Swanson Wendy Sue , Archibald Sarah , Diekema Douglas
Published: September 2007

OBJECTIVE. The National Residency Matching Program allows match participants to recruit each other and try to influence future ranking decisions in their favor, but it also states that participants “must not make statements implying commitment.” The National Residency Matching Program cautions against statements such as, “We plan to rank you very highly on our list,” because they can be misinterpreted as an informal commitment. To avoid issues around miscommunication, the University of Washington Pediatric Residency Program instituted a postinterview no-call policy with applicants. The purpose of this study was to determine this policy's impact on applicants.

METHODS. A Web-based, anonymous survey was sent after the National Residency Matching Program deadline for submitting rank lists but before match day to applicants who interviewed at our program from 2003 to 2006. Applicants were asked whether our program's position on their rank list would have been influenced more favorably, less favorably, or not at all had they received a telephone call from our program.

RESULTS. The survey response rate was 53% (n = 468). A total of 10.3% (n = 48) of the applicants to our program would have been favorably influenced by a telephone call after their interview. Significantly more applicants reported that a recruiting call from our program would have caused them to rank our program more favorably in 2006 (17.2%) than in 2003–2005 combined (8.4%).

CONCLUSIONS. We identified a vulnerable applicant population whose rank lists are potentially influenced by questionable postinterview communication from residency programs. To protect the integrity and fairness of the match, we call for more explicit guidelines regarding postinterview communication with applicants.
Unbekannte Liszt-Dokumente in der Braun’schen Autographen-Sammlung im Cotta-Archiv von Marbach
Authors: Gracza Lajos
Published: September 2007

Zwei Briefe von Liszt an Charlotte von Oven (1809–1891) sind hier zum ersten Male veröffentlicht. Liszt hatte die Schauspielerin 1842 in Berlin kennen gelernt. Die Briefe lassen sich vom Herbst 1963 datieren. Die intime Diktion der Briefe dokumentieren das Verhältnis von Liszt zum schönen Geschlecht.
Medical Tables, Graphics and Photographs: How They Work
Authors: Gross Alan G.
Published: September 2007

An examination of a random sample of four medical journals— The Lancet, The New England Journal of Medicine, The Journal of the American Medical Association, and The Journal of Laboratory and Clinical Medicine—reveals that one-fifth of the space of articles in medical science is devoted to an average of three tables and three flow charts, graphs, or photographs. Given these figures, the absence of discussion of visuals in the literature on medical communication may seem puzzling. But the puzzle is easily solved: our basic education gives us a coherent vocabulary for talking about prose, but no coherent vocabulary for talking about tables and visuals. Once we have this vocabulary in hand, we make another step in the direction of an explanation of the nature of communication in the medical sciences. We may note that understanding the meaning of a medical article is not just a consequence of understanding its texts; it is a consequence of understanding all its meaningful components working together—verbal, tabular, visual.
Implementation of Medical Research Findings through Insulin Protocols: Initial Findings from an Ongoing Study of Document Design and Visual Display
Authors: Longo Bernadette , Weinert Craig , Fountain T. Kenny
Published: September 2007

Medical personnel in hospital intensive care units routinely rely on protocols to deliver some types of patient care. These protocol documents are developed by hospital physicians and staff to ensure that standards of care are followed. Thus, the protocol document becomes a de facto standing order, standing in for the physician's judgment in routine situations. This article reports findings from Phase I of an ongoing study exploring how insulin protocols are designed and used in intensive care units to transfer medical research findings into patient care “best practices.” We developed a taxonomy of document design elements and analyzed 29 insulin protocols to determine their use of these elements. We found that 93% of the protocols used tables to communicate procedures for measuring glucose levels and administering insulin. We further found that the protocols did not adhere well to principles for designing instructions and hypothesized that this finding reflected different purposes for instructions (training) and protocols (standardizing practice).
Fear reactivity and effortful control in overt and relational bullying: a six‐month longitudinal study
Authors: Terranova Andrew M. , Morris Amanda Sheffield , Boxer Paul
Published: September 2007

This study examined the roles of fear reactivity and emotional regulatory abilities in overt and relational bullying behaviors. Survey data were collected from 124 middle school students (mean age=10.3 years, 47% males, 61% Caucasian) and their teachers in the fall and spring of a school year. Surveys included teacher‐ and self‐rated measures of students' overt and relational bullying along with self‐reported fear reactivity and effortful control. Findings show that low levels of fear reactivity and effortful control predict higher future levels of overt bullying, but not relational bullying. These results suggest that despite high correlations between overt and relational bullying, these two forms of aggression develop through different processes. The findings from this investigation are discussed with respect to their implications for theory on the development of aggression as well as prevention and intervention programming for youth aggression. Aggr. Behav. 34:104–115, 2008. ©2007 Wiley‐Liss, Inc.
Spectrophotometric Characterisation of Surface Lakewater Samples: Implications for the Quantification of Nitrate and the Properties of Dissolved Organic Matter
Authors: Minero Claudio , Lauri Vittorio , Falletti Gianpaolo , Maurino Valter , Pelizzetti Ezio , Vione Davide
Published: September 2007

Filtered lakewater samples, mainly collected in the province of Torino (Piedmont, NW Italy) were characterised from a spectrophotometric point of view. Spectral data were then used for the direct determination of nitrate by three‐wavelength photometry, which should account for the spectral interference by dissolved organic matter (DOM), and the results compared with nitrate quantification by ion chromatography. The spectrophotometric method proved very suitable for nitrate measurement, with unity slope (μ±σ = 0.99±0.03) of the correlation plot (spectral vs. ion chromatography data) up to 0.1 mM nitrate, and with r2 = 0.97 for 26 data points. Lakewater spectra were also used for the characterisation of DOM bymeans of the specific absorption at 285 and 254 nm (absorbance vs. NPOC, the latter to quantify the DOM amount), and the E2/E3 and E3/E4 indexes. The latter two make only use of radiation absorption data (250 vs. 365 and 300 vs. 400 nm). It could be concluded that lakewater DOM is mainly composed of autochthonous material (biologically produced aliphatic compounds and only a minor fraction of aromatic groups), with generally low molecular weight and degree of aromaticity. Some exceptions could be found in high‐mountain lakes, but it should also be considered that NPOC measurement cannot be avoided if DOM origin is to be studied. From the absorption spectrum alone it is possible to get indication on the aromaticity degree of radiation‐absorbing DOM, but most of the autochthonous DOM would escape spectrophotometric characterisation.
The Degradation Products of Aniline in the Solutions with Ozone and Kinetic Investigations
Authors: Turhan Kadir , Uzman Suheyla
Published: September 2007

Aromatic compounds are extensively used in several industries and can cause pollution in water sources. This work aims at examining the degradability of aniline in aqueous solutions by ozone‐induced cleavage, and at determining the kinetics of the cited cleavage reactions. Aniline was prepared in four different concentrations and the flow rate of ozone supplied to each solution was selected. Aniline solutions were ozonated at low and high pH, so as to compare both molecular and hydroxyl free radical mechanisms, respectively. The main identified aromatic by‐products were nitrobenzene and azobenzene when the experiment was carried out at acidic pH. Formation of nitrobenzene, azobenzene, azoxybenzene and 2‐pyridine carboxylic acid (picolinic acid) was observed when the ozonization was carried out at basic pH. All the aromatic by‐products found were less toxic than the raw materials. The pseudo‐first‐order constants in aniline concentrations were calculated.
Oral and physiological paleohealth in cold adapted peoples: Northeast Asia, Hokkaido
Authors: Oxenham Marc F. , Matsumura Hirofumi
Published: September 2007

This paper examines variables useful in reconstructing oral (caries, antemortem tooth loss, alveolar defects) and physiological (cribra orbitalia, linear enamel hypoplasia) well‐being in two bioarchaeological assemblages from Hokkaido, Japan: Okhotsk (n=37 individuals) and Jomon (n=60). Findings are compared and contrasted with each other, with published series from Honshu Japan, and samples from climatically near‐equivalent Alaska. It was found that more meaningful comparisons of Hokkaido paleohealth could be made with Alaskan material, rather than the more southerly Jomon. Results were ambiguous with respect to physiological well‐being. Low levels of LEH in the cold‐adapted samples suggest operating in arctic and subarctic environments with marine‐based subsistence regimes is not physiologically expensive. However, the relatively high levels of cribra orbitalia in Hokkaido, relative to Alaska, suggest the picture is not straightforward: the reasons for elevated cribra orbitalia in Hokkaido are unclear. The subarctic and arctic samples formed three broadly similar groupings in terms of oral health profiles: (1) Aleuts and Eskimo; (2) Ipiutak and Tigara; (3) Hokkaido Jomon, Okhotsk, and Kodiak Island. Differences between these groupings could be explained with a combination of sample demographics and subsistence orientations. The extremely high frequency of caries in one sample, caribou hunting Ipiutak, may have been influenced by factors such as low levels of dietary magnesium and potentially cariogenic foodstuffs, such as preparations of caribou stomach contents. It was concluded that oral health profiles are potentially sensitive to differences in subsistence strategies among cold‐adapted hunter–gatherers, although they lack predictive value. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Trophy heads from Nawinpukio, Perú: Physical and chemical analysis of Huarpa‐era modified human remains
Authors: Finucane Brian Clifton
Published: September 2007

Rescue excavations at the site of Nawinpukio in Perú's Ayacucho Valley exposed a cache of fragmented skulls dating to the Huarpa‐era, about AD 400–700. Physical analysis of these remains revealed that they belonged to individuals of both sexes and a range of ages (MNI = 8), and that four crania had been modified through drilling, cutting, and scraping. The occipital and parietal bones of one cranium had been modified to form a shallow basin. Carbon stable isotope analysis of these remains revealed that five individuals had isotopic signatures consistent with maize consumption and one individual exhibited a carbon isotope value indicative of a C3 plant based diet. Such a nonmaize diet distinguishes this individual from all other prehistoric humans analyzed from the Ayacucho Valley and is consistent with an origin a different ecozone of the valley. On the basis of their physical properties it is argued that these remains represent trophies obtained during raiding. Drawing on the formal properties of the specimens as well as ethnographic and archaeological analogies, it is suggested that the cranial basin served as a vessel for liquid. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Impaired human hippocampal neurogenesis after treatment for central nervous system malignancies
Authors: Monje Michelle L. , Vogel Hannes , Masek Marilyn , Ligon Keith L. , Fisher Paul G. , Palmer Theo D.
Published: September 2007

The effects of cancer treatments such as cranial radiation and chemotherapy on human hippocampal neurogenesis remain unknown. In this study, we examine neuropathological markers of neurogenesis and inflammation in the human hippocampus after treatment for acute myelogenous leukemia or medulloblastoma. We demonstrate a persistent radiation‐induced microglial inflammation that is accompanied by nearly complete inhibition of neurogenesis after cancer treatment. These findings are consistent with preclinical animal studies and suggest potential therapeutic strategies. Ann Neurol 2007
Protecting biodegradable coatings releasing antimicrobial agents
Authors: Fay Fabienne , Linossier Isabelle , Langlois Valérie , Vallee‐Rehel Karine , Krasko Michal Y. , Domb Abraham J.
Published: September 2007

This article describes the synthesis and in vitro analysis of poly(ester anhydride) antimicrobial protection coatings. Poly(ester anhydride)s composed of ricinoleic acid, sebacic acid, terephthalic acid, and isophthalic acid were used in this study. The polymers were compatible with various fillers commonly used in paint preparation. The in vitro experiments showed that the polymers are able to release diuron, an antimicrobial agent, for months. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Rheological, mechanical, and morphological studies of epoxy/poly(methyl methacrylate) semi‐interpenetrating polymer networks
Authors: Siddaramaiah  , Barcia Fábio L. , Sirqueira Alex S. , Paranhos Caio M. , Soares Bluma G.
Published: September 2007

Semi‐interpenetrating polymer networks (semi‐IPNs) of epoxy resin and poly(methyl methacrylate) (PMMA) were synthesized. Methyl methacrylate (MMA) was polymerized by free radical mechanism with azo‐bis‐isobutyronitrile in the presence of oligomeric epoxy resin (DGEBA), and hexahydrophthalic anhydride as crosslinking agent. The gelation and vitrification transitions during cure/polymerization processes have been examined using parallel‐plates rheological technique. From differential scanning calorimetry and rheological techniques, it was suggested that both curing and polymerization processes occur simultaneously. However, the gelation time was longer for the semi‐IPN than those observed for the cure of pure DGEBA or polymerization of MMA. The gelation time increased significantly when 5% of MMA was employed, suggesting a diluent effect of the monomer. Higher amount of MMA resulted in a decrease of gel time, probably because of the simultaneous polymerization of MMA during the curing process. Structural examination of the semi‐IPNs, using scanning electron microscopy, revealed phase separation in nanoscale size for semi‐IPNs containing PMMA at concentrations up to 15%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis of new alicyclic polyimides by Diels‐Alder polymerization
Authors: Chi Jun Ho , Shin Gyo Jic , Kim Yong Seok , Jung Jin Chul
Published: September 2007

Four new alicyclic poly{arylene‐9,10‐di[4‐(methyloxy)phenyloxy]‐1,2,3,4,5,6,7,8‐octahydroanthracene‐2,3,6,7‐tetracarboxdiimide}s (APIs) were prepared at 80°C in the presence of NaI in DMSO by the in situ Diels‐Alder polymerization of 1,4‐bis[4‐(methyloxy)phenyloxy]‐2,3,6,7‐tetrakis(bromomethyl)benzene (MPBB) with four arylenebismaleimides (AMIs). The stereochemical isomerisms measured for the model compound DPAI and MDA‐PI by HETCOR spectroscopy and 1H‐NMR spectroscopy, respectively, revealed that DPAI and APIs presumably have only one trans‐bis‐endo‐configuration. Inherent viscosities of APIs varied in the 0.20–0.41 dL/g range. Solubility tests revealed that in spite of the alicyclic units incorporated the APIs were only marginally soluble in polar organic solvents. In TGA in N2 the APIs began to decompose at temperatures higher than 380°C, revealing two‐step pyrolysis behavior. 4‐(Methyloxy)phenyloxy side groups were believed to degrade in the lower temperature range. In DSC and wide‐angle X‐ray diffractometry APIs all appeared completely amorphous and in UV‐Vis spectroscopy both DPAI and APIs were transparent at wavelengths longer than 375 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of different anchor groups on adsorption behavior and effectiveness of poly(N,N‐dimethylacrylamide‐co‐Ca 2‐acrylamido‐2‐methylpropanesulfonate) as cement fluid loss additive in presence of acetone–formaldehyde–sulfite dispersant
Authors: Plank Johann , Brandl Andreas , Lummer Nils Recalde
Published: September 2007

The impact of various anchor groups on adsorption behavior of AMPS® copolymers was studied. The anchor groups differ in anionic charge density. Copolymer adsorption and water retention of oil well cement slurries achieved from CaAMPS®‐co‐NNDMA in the presence of an acetone–formaldehyde–sulfite (AFS) dispersant were improved by incorporation of minor amounts (∼ 1% by weight of polymer) of acrylic acid (CaAMPS®‐co‐NNDMA‐co‐AA), maleic acid anhydride (CaAMPS®‐co‐NNDMA‐co‐MAA), or vinyl phosphonic acid (CaAMPS®‐co‐NNDMA‐co‐VPA), respectively. Performance of these terpolymers was studied by measuring static filtration properties of oil well cement slurries at 27°C and 70 bar pressure. All fluid loss additives possess comparable molar masses and show the same adsorption behavior and effectiveness when no other admixture is present. In the presence of AFS dispersant, however, adsorption of CaAMPS®‐co‐NNDMA and hence fluid loss control is dramatically reduced, whereas effectiveness of CaAMPS®‐co‐NNDMA‐co‐AA is less influenced because of acrylic acid incorporated as additional anchor group. Even more, CaAMPS®‐co‐NNDMA‐co‐MAA combined with AFS allows simultaneous adsorption of both polymers and thus produces good fluid loss control. CaAMPS®‐co‐NNDMA‐co‐VPA no longer allows adsorption of AFS dispersant. This was also confirmed by rheological measurements. The results show that, in a binary admixture system, adsorption of the anionic polymer with anchor groups possessing higher charge density is preferred. Surface affinity of the anchor groups studied increase in the order SO → COO− → vic‐(COO−)2→ PO. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Morphological and structural development of poly(ether ether ketone) during mechanical pulverization
Authors: Liang Mei , Lu Canhui , Huang Yigang , Zhang Changsheng
Published: September 2007

Micron size particles of poly(ether ether ketone) (PEEK) were prepared by self‐made pan‐type milling equipment operated at ambient temperature. The changes of particle morphology, crystalline properties, thermal behavior, and viscosity‐average molecular mass during milling were studied by SEM, WAXD, DSC, TGA, and viscosimetry analyses, respectively. SEM analysis indicated that pan‐milling firstly destroyed the original structure of PEEK through squeezing in‐between mill pans, then to produce fine powder undergoing the processes of deforming and size reduction. The average particle size of PEEK was reduced to 100 μm only after 5 cycles of pan‐milling and reached less than 50 μm after 50 cycles. DSC analysis showed that crystallinity of PEEK decreased with the pan‐milling cycles, agreed with WAXD data. The crystallinity of PEEK decreased from 46.2 to 39.9% of 50 pan‐milling cycles was offered. The glass transition temperature increased slightly along with pan‐milling cycles. Mechanochemical effects caused by pan‐milling were also studied. Viscometer test exhibited that molecular weight dropped quickly at earlier pan‐milling stage then decreased slightly during later pan‐milling. Pan‐milling technique is an efficient, clean, and environmental friendly method for preparing fine PEEK powder. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Poly(methyl methacrylate)‐modified vinyl ester thermosets: Morphology, volume shrinkage, and mechanical properties
Authors: Schroeder Walter F. , Borrajo Julio , Aranguren Mirta I.
Published: September 2007

Thermoset materials obtained from styrene/vinyl ester resins of different molecular weights modified with poly(methyl methacrylate) (PMMA) were prepared and studied. Scanning electron microscopy and transmission electron microscopy micrographs of the fracture surfaces allowed the determination of a two‐phase morphology of the modified networks. Depending on the molecular weight of the vinyl ester oligomer, the initial content of the PMMA additive, and the selected curing temperature, different morphologies were obtained, including the dispersion of thermoplastic‐rich particles in a thermoset‐rich matrix, cocontinuous structures, and the dispersion of thermoset‐rich particles in a thermoplastic‐rich matrix (phase‐inverted structure). Density measurements were performed to determine the effect of the PMMA‐modifier concentration and curing temperature on the volume shrinkage of the final materials. The development of cocontinuous or thermoplastic‐rich matrices was not too effective in controlling the volume shrinkage of the studied vinyl ester systems. The evaluation of the dynamic mechanical behavior, flexural modulus, compressive yield stress, and fracture toughness showed that the addition of PMMA increased the fracture resistance without significantly compromising the thermal or mechanical properties of the vinyl ester networks. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Impacts of impregnation with Timbercare Aqua on the red and yellow color tone of some woods and varnishes
Authors: Keskin Hakan , Atar Musa
Published: September 2007

This study has been performed for determining the effects of impregnation with Timbercare Aqua (Tc) on the red and yellow color tone of some woods and varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods, which met the requirements of ASTM D 358, was impregnated with Tc according to ASTM D 1413 and producer's definition. After impregnation, wood surfaces have been coated by Sayerlack parquet varnish (Sp), Sayerlack interior varnish (Si), and Sayerlack exterior varnish (Se) varnishes in accordance with the ASTM D 3023 standards. According to ASTM D 2244, the red and yellow color tone of samples after varnishing process was determined. As a result, the value of red color tone was the highest in Oriental beech (15.21) and the lowest in Uludag fir (5.38). For the wood material, impregnation material, and varnish interaction, the red color tone value was the highest in Oriental beech + Tc + Sp (18.43) and the lowest in Uludag fir + Tc + Si (3.92). The value of the yellow color tone was the highest in pine (34.45) and the lowest in Oriental beech (26.50). For the wood material, impregnation material, and varnish interaction, the yellow color tone value was the highest in Oriental spruce + Tc + Sp (42.12) and the lowest in Oriental beech + Tc + Si (21.47). This effect may be due to the impacts of impregnation chemical on wood extractives and color pigments in varnish. Accordingly, it should be taken into care for applications where the red and yellow color tone value is important. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Pervaporation performance of polystyrene membrane surface with perfluoroalkyl groups
Authors: Ni HuaGang , Zhang Hao , Wang XiaoBin , Wang XinPing
Published: September 2007

Research on the effect of various chemical groups on the pervaporation performance of membranes was very important for understanding the separation phenomenon. In this article, a polystyrene membrane with CF3 groups on its surface was prepared by casting normal polystyrene (PS‐H) solution with small‐molecular‐weight α,ω‐fluoroalkyl‐terminated polystyrene (S‐PS‐(CF3)2) on a glass plate. The amount of CF3 groups on the surface was adjusted by changing S‐PS‐(CF3)2 content, which was documented by X‐ray photoelectron spectroscopy analysis, surface energy, and contact angle measurements. The effect of S‐PS‐(CF3)2 content on separation performance of S‐PS‐(CF3)2/PS‐H blend membranes for ethanol/water mixture was investigated. The results showed that water concentration in the permeate decreased with increasing S‐PS‐(CF3)2 content; however, the permeation rate did not change until the S‐PS‐(CF3)2 content was increased to 1 wt %. The reason for this was attributed to the fact that a small amount of S‐PS‐(CF3)2 enables a simple surface modification of the membrane keeping its inner structure relatively unchanged. This was confirmed by swelling degree measurements and other experiments. Comparison with our previous work showed that the CF3 groups on the surface lowers the water permselectivity of the polystyrene membranes, whereas the COOH groups enhance the water permselectivity. However, neither hydrophobic CF3 nor hydrophilic groups on the membrane surface appeared to have any influence on flux. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Analysis of polyolefins and olefin copolymers using Crystaf technique: Resolution of Crystaf curves
Authors: Kissin Yury V. , Fruitwala Hitesh A.
Published: September 2007

An experimental technique, crystallization analysis fractionation (Crystaf), is used to analyze compositional uniformity of ethylene/α‐olefin copolymers and isotactic polypropylene. A computerized method for quantifying Crystaf data is developed based on resolution of Crystaf curves into their elemental components, with each component representing a fraction of the polymer with the same degree of chain imperfection. This analysis of Crystaf curves gives three parameters characterizing crystallizable polymer material: (a) the number of compositionally uniform components, (b) properties of each compositionally uniform component (in the case of ethylene/α‐olefin copolymers, the comonomer content), and (c) the quantity of each component. Crystaf analysis of several ethylene/1‐hexene copolymers produced with supported Ti‐based Ziegler‐Natta catalysts shows the existence of two groups of copolymer components. The first group includes components with low comonomer content, in the Crystaf analysis they precipitate at high temperatures as several relatively sharp peaks. The second group includes components with high comonomer contents; they precipitate at much lower temperatures, as a broad overlapping group of peaks. The peak resolution technique was applied to analysis of ethylene/α‐olefin copolymers prepared with a supported catalyst at different temperatures, a copolymer produced with a pseudo‐homogenous Ziegler‐Natta catalyst, and to isotactic polypropylene. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Visualizing the marrow of science
Authors: Moya‐Anegón SCImago Group: Félix de , Vargas‐Quesada Benjamín , Chinchilla‐Rodríguez Zaida , Corera‐Álvarez Elena , Munoz‐Fernández Francisco J. , Herrero‐Solana Victor
Published: September 2007

This study proposes a new methodology that allows for the generation of scientograms of major scientific domains, constructed on the basis of cocitation of Institute of Scientific Information categories, and pruned using PathfinderNetwork, with a layout determined by algorithms of the spring‐embedder type (Kamada–Kawai), then corroborated structurally by factor analysis. We present the complete scientogram of the world for the Year 2002. It integrates the natural sciences, the social sciences, and arts and humanities. Its basic structure and the essential relationships therein are revealed, allowing us to simultaneously analyze the macrostructure, microstructure, and marrow of worldwide scientific output.
Silver(I) Double and Multiple Salts Containing the 1,3‐Butadiynediide Dianion: Coordination Diversity and Assembly with the Supramolecular Synthon Ag4⊂CCCC⊃Ag4
Authors: Zhao Liang , Du Miao , Mak Thomas C. W.
Published: September 2007

A series of 13 silver(I) double and multiple salts containing 1,3‐butadiynediide, C42−, were synthesized by dissolving the silver carbide Ag2C4 in a concentrated aqueous solution of one or more of the silver salts AgNO3, AgCF3CO2, AgC2F5CO2, AgF, AgBF4, and AgPF6. The 1,3‐butadiynediide anion invariably adopts a μ4,μ4 coordination mode in these compounds, which indicates that the Ag4⊂CCCC⊃Ag4 moiety can be used as a new type of metalloligand supramolecular synthon for the construction of coordination networks. Fine‐tuning with various ancillary anionic ligands caused the Ag4 aggregate at each ethynide terminus to adopt a butterfly‐shaped, planar, or barblike configuration, within which the silver–ethynide interactions can be classified into three types: σ, π, and mixed (σ,π). The effect of coexisting nitrile ligands and quaternary ammonium salts on supramolecular assembly with the above synthon was also explored. The hydrolysis of PF6− and BF4− led to the formation of the quadruple salt Ag2C4⋅4 AgNO3⋅AgPF2O2⋅Ag3PO4 and a novel (F)2(H2O)18 hydrogen‐bonded tape in the triple salt Ag2C4⋅2 AgF⋅ 10 AgC2F5CO2⋅CH3CN⋅12 H2O, respectively. The largest silver–ethynide cluster aggregate described to date, (C4)3@Ag18, occurs in 3 Ag2C4⋅ 12 AgC2F5CO2⋅5[(BnMe3N)C2F5CO2]⋅ 4 H2O (Bn=benzyl).
Empfehlungen des Arbeitskreises 6.1 “Geotechnik der Deponiebauwerke” der Deutschen Gesellschaft für Geotechnik e., V. (DGGT)
Authors: Witt Karl Josef , Ramke Hans‐Günter
Published: September 2007

Der Arbeitskreis Geotechnik der Deponiebauwerke hat in den Empfehlungsgruppen E1 bis E5 bisher 76 Empfehlungen veröffentlicht. Die jährliche Publikation wird fortgesetzt durch eine grundlegend überarbeitete Fassung der zuletzt im Jahre 2001 erschienenen Empfehlung E2‐36 “Oberflächenabdichtungssysteme mit Tondichtungsbahnen”. In die Überarbeitung sind die jüngsten Forschungsergebnisse, Erfahrungen mit der Planung, dem Bau und der messtechnischen Überwachung von Maßnahmen eingeflossen.
Ermittlung der Einbindetiefe von Stützwänden mit dem Verfahren nach Blum unter Nutzung des Teilsicherheitskonzepts
Authors: Winkler Andreas
Published: September 2007

Das Verfahren nach Blum hat sich in den letzten Jahrzehnten zur Ermittlung der Einbindetiefe bei Baugrubenwänden etabliert. Mit Einführung des Teilsicherheitskonzepts auf Grundlage der DIN 1054 kann bei getrennter Betrachtung des Widerstandes sowie der ständigen und veränderlichen Einwirkungen das Verfahren nicht mehr in seiner bisherigen Form eingesetzt werden. Durch entsprechende Modifizierungen ist der Einsatz des Verfahrens nach Blum als einfache, per Hand durchführbare Berechnungsmethode weiterhin möglich. Im Fall, dass keine veränderlichen Einwirkungen vorhanden sind, kann weiterhin die Einbindetiefe direkt ermittelt werden (Verfahren I). Andernfalls kann durch Variation der Einbindetiefe gezielt ein vorgebbarer Ausnutzungsgrad des Erdwiderlagers für den Nachweis im Grenzzustand GZ 1B erreicht werden (Verfahren II). Die leicht handhabbaren Berechnungsalgorithmen werden für beide Verfahren jeweils für die eingespannte ungestützte Wand, die einfach gestützte frei aufgelagerte Wand und die einfach gestützte eingespannte Wand vorgestellt.
Berücksichtigung des Frischbetondrucks bei der FE‐Simulation der Schlitzwandherstellung
Authors: Loreck Christoph , Triantafyllidis Theodor
Published: September 2007

Baugrundverformungen im Umfeld einer Schlitzwandbaugrube entstehen sowohl aus dem Baugrubenaushub als auch aus der Herstellung der Baugrubenwand selbst. Für die numerische Simulation der Schlitzwandherstellung sind die Berücksichtigung der Herstellungsreihenfolge sowie der im Boden induzierten Spannungszustände aus Suspensions‐ und Frischbetondruck in einem 3D‐Modell erforderlich. Zur Frage der Frischbetondruckentwicklung in Schlitzwandlamellen wurden Zentrifugenmodellversuche und Elementversuche durchgeführt und ein Berechnungsmodell abgeleitet, das die verfügbaren Baustellenmessungen gut wiedergibt und eine differenzierte Berücksichtigung des Frischbetondrucks in FE‐Simulationen ermöglicht.
Assessment of magnetic fields surrounding electronic article surveillance systems in Sweden
Authors: Trulsson Jimmy , Anger Gert , Estenberg Ulrika
Published: September 2007

Magnetic fields surrounding 11 EAS systems in Swedish shops and libraries were measured, in real‐life conditions, according to the CENELEC standard. For each system, the arithmetic mean of 45 measurement points was compared to ICNIRP's reference level. Six of eleven measured systems exceeded the reference levels. Bioelectromagnetics 28:664–666, 2007. © 2007 Wiley‐Liss, Inc.
Direct current electrical fields induce apoptosis in oral mucosa cancer cells by NADPH oxidase‐derived reactive oxygen species
Authors: Wartenberg Maria , Wirtz Nina , Grob Alexander , Niedermeier Wilhelm , Hescheler Jürgen , Peters Saskia C. , Sauer Heinrich
Published: September 2007

The presence of more than one dental alloy in the oral cavity often causes pathological galvanic currents and voltage resulting in superficial erosions of the oral mucosa and eventually in the emergence of oral cancer. In the present study the mechanisms of apoptosis of oral mucosa cancer cells in response to electromagnetic fields was investigated. Direct current (DC) electrical fields with field strengths between 2 and 16 V/m, applied for 24 h to UM‐SCC‐14‐C oral mucosa cancer cells, dose‐dependently resulted in decreased cell proliferation as evaluated by Ki‐67 immunohistochemistry and upregulation of the cyclin‐dependent kinase (CDK) inhibitors p21cip1/waf1 and p27kip1, which are associated with cell cycle arrest. Electrical field treatment (4 V/m, 24 h) increased apoptosis as evaluated by immunohistochemical analysis of cleaved caspase‐3 and poly‐(ADP‐ribose)‐polymerase‐1 (PARP‐1). Furthermore, robust reactive oxygen species (ROS) generation, increased expression of NADPH oxidase subunits as well as Hsp70 was observed. Electrical field treatment (4 V/m, 24 h) resulted in increased expression of Cu/Zn superoxide dismutase and decreased intracellular concentration of reduced glutathione (GSH), whereas the expression of catalase remained unchanged. Pre‐treatment with the free radical scavenger N‐acetyl cysteine (NAC) and the superoxide dismutase mimetic EUK‐8 abolished caspase‐3 and PARP‐1 induction, suggesting that apoptosis in oral mucosa cancer cells is initated by ROS generation in response to DC electrical field treatment. Bioelectromagnetics 29:47–54, 2008. © 2007 Wiley‐Liss, Inc.
Optimization of oxygen mass transfer in a multiphase bioreactor with perfluorodecalin as a second liquid phase
Authors: Amaral Priscilla F.F. , Freire Mara G. , Rocha‐Leão Maria Helena M. , Marrucho Isabel M. , Coutinho João A.P. , Coelho Maria Alice Z.
Published: September 2007

Oxygenation is an important parameter involved in the design and operation of mixing–sparging bioreactors and it can be analyzed by means of the oxygen mass transfer coefficient (kLa). The operational conditions of a stirred, submerged aerated 2‐L bioreactor have been optimized by studying the influence of a second liquid phase with higher oxygen affinity (perfluorodecalin or olive oil) in the kLa. Using kLa measurements, the influence of the following parameters on the oxygen transfer rate was evaluated: the volume of working medium, the type of impellers and their position, the organic phase concentration, the aqueous phase composition, and the concentration of inactive biomass. This study shows that the best experimental conditions were achieved with a perfluorodecalin volume fraction of 0.20, mixing using two Rushton turbines with six vertical blades and in the presence of YPD medium as the aqueous phase, with a kLa value of 64.6 h−1. The addition of 20% of perfluorodecalin in these conditions provided a kLa enhancement of 25% when pure water was the aqueous phase and a 230% enhancement when YPD medium was used in comparison to their respective controls (no perfluorodecalin). Furthermore it is shown that the presence of olive oil as a second liquid phase is not beneficial to the oxygen transfer rate enhancement, leading to a decrease in the kLa values for all the concentrations studied. It was also observed that the magnitude of the enhancement of the kLa values by perfluorodecalin depends on the biomass concentration present. Biotechnol. Bioeng. 2008;99: 588–598. © 2007 Wiley Periodicals, Inc.
Engineering poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) copolymer composition in E. coli
Authors: Wong Matthew S. , Causey Thomas B. , Mantzaris Nikos , Bennett George N. , San Ka‐Yiu
Published: September 2007

A strain of Escherichia coli was metabolically engineered to produce poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) of specified composition between 5% and 18% HV. A gene encoding propionyl‐CoA synthetase (prpE from S. enterica) was placed under the control of the IPTG‐inducible tac promoter (PtaclacUV5) while the polyhydroxyalkanoate synthesis operon (phaBCA) from R. eutropha was expressed constitutively. A strain of E. coli harboring both plasmids was grown in defined medium and PHBV was produced with specified hydroxyvalerate (HV) molar content between 5% and 18%. The molecular weight of the copolymer was ∼700,000 across various HV contents, and average polydispersity was ∼ 1.3. The majority of the PHBV production occurred during the late exponential/stationary phase. The HV content of the copolymer generally peaked early in the incubation before falling to its final value. We found that the time profiles of PrpE activity, propionyl‐CoA, and acetyl‐CoA were well correlated to the HV content time profile. Despite an abundance of propionyl‐CoA, incorporation of HV into the copolymer was inefficient. Therefore, both the PHA operon and conditions affecting the availability of propionyl‐CoA must be chosen carefully to achieve the desired HV content. The ability to engineer copolymer composition control into an E. coli strain would be useful in cases where the feedstock composition is not adjustable. Biotechnol. Bioeng. 2008;99: 919–928. © 2007 Wiley Periodicals, Inc.
Protein engineering of nitrilase for chemoenzymatic production of glycolic acid
Authors: Wu Shijun , Fogiel Arthur J. , Petrillo Kelly L. , Jackson Raymond E. , Parker Kimberley N. , DiCosimo Robert , Ben‐Bassat Arie , O'Keefe Daniel P. , Payne Mark S.
Published: September 2007

A key step in a chemoenzymatic process for the production of high‐purity glycolic acid (GLA) is the enzymatic conversion of glycolonitrile (GLN) to ammonium glycolate using a nitrilase derived from Acidovorax facilis 72W. Protein engineering and over‐expression of this nitrilase, combined with optimized fermentation of an E. coli transformant were used to increase the enzyme‐specific activity up to 15‐fold and the biocatalyst‐specific activity up to 125‐fold. These improvements enabled achievement of the desired volumetric productivity and biocatalyst productivity for the conversion of GLN to ammonium glycolate. Biotechnol. Bioeng. 2008;99: 717–720. © 2007 Wiley Periodicals, Inc.
Combining classification and regression approaches for the quantification of highly overlapping capillary electrophoresis peaks by using evolutionary sigmoidal and product unit neural networks
Authors: Hervás Cesar , Gutierrez Pedro Antonio , Silva Manuel , Serrano Juan Manuel
Published: September 2007

This is a study of the potential of neural networks built by using different transfer functions (sigmoidal, product and sigmoidal–product units) designed by an evolutionary algorithm to quantify highly overlapping electrophoretic peaks. To test this approach, two aminoglycoside antibiotics, amikacin and paramomycin, were quantified from samples containing either only one component or mixtures of them though capillary zone electrophoresis (CZE) with laser‐induced fluorescence (LIF) detection. The three models assayed used as input data the four‐parameter Weibull curve associated with the profile of the electrophoretic peak and in some cases the class label for each sample estimated by cluster analysis. The combination of classification and regression approaches allowed the establishment of straightforward network topologies enabling the analytes to be quantified with great accuracy and precision. The best models for mixture samples were provided by product unit neural networks (PUNNs), 4:4:1 (14 weights) for both analytes, after discrimination by cluster analysis, allowing the analytes to be quantified with great accuracy: 8.2% for amikacin and 5.6% for paromomycin within the standard error of prediction for the generalization test, SEPG. For comparison, partial least square regression was also used for the resolution of these mixtures; it provided a minor accuracy: SEPG 11.8 and 15.7% for amikacin and paramomycin, respectively. The reduced dimensions of the neural networks models selected enabled the derivation of simple quantification equations to transform the input variables into the output variable. These equations can be more easily interpreted from a chemical point of view than those provided by other ANN models. Copyright © 2007 John Wiley & Sons, Ltd.
A randomization test for PLS component selection
Authors: Wiklund Susanne , Nilsson David , Eriksson Lennart , Sjöström Michael , Wold Svante , Faber Klaas
Published: September 2007

During the last two decades, a number of methods have been developed and evaluated for selecting the optimal number of components in a PLS model. In this paper, a new method is introduced that is based on a randomization test. The advantage of using a randomization test is that in contrast to cross validation (CV), it requires no exclusion of data, thus avoiding problems related to data exclusion, for example in designed experiments. The method is tested using simulated data sets for which the true dimensionality is clearly defined and also compared to regularly used methods for 10 real data sets. The randomization test works as a good statistical selection tool in combination with other selection rules. It also works as an indicator when the data require a pre‐treatment. Copyright © 2007 John Wiley & Sons, Ltd.
Evidence for Significant Through‐Space and Through‐Bond Electronic Coupling in the 1,4‐Diphenylcyclohexane‐1,4‐diyl Radical Cation Gained by Absorption Spectroscopy and DFT Calculations
Authors: Ikeda Hiroshi , Hoshi Yosuke , Namai Hayato , Tanaka Futoshi , Goodman Joshua L. , Mizuno Kazuhiko
Published: September 2007

Photoinduced single‐electron‐transfer promoted oxidation of 2,5‐diphenyl‐1,5‐hexadiene by using N‐methylquinolinium tetrafluoroborate/biphenyl co‐sensitization takes place with the formation of an intense electronic absorption band at 476 nm, which is attributed to the 1,4‐diphenylcyclohexane‐1,4‐diyl radical cation. The absorption maximum (λob) of this transient occurs at a longer wavelength than is expected for either the cumyl radical or the cumyl cation components. Substitution at the para positions of the phenyl groups in this radical cation by CH3O, CH3, F, Cl, and Br leads to an increasingly larger redshift of λob. A comparison of the ρ value, which was obtained from a Hammett plot of the electronic transition energies of the radical cations versus σ+, with that for the cumyl cation shows that the substituent effects on the transition energies for the 1,4‐diarylcyclohexane‐1,4‐diyl radical cations are approximately one half of the substituent effects on the transition energies of the cumyl cation. The observed substituent‐induced redshifts of λob and the reduced sensitivity of λob to substituent changes are in accordance with the proposal that significant through‐space and ‐bond electronic interactions exist between the cumyl radical and the cumyl cation moieties of the 1,4‐diphenylcyclohexane‐1,4‐diyl radical cation. This proposal gains strong support from the results of density functional theory (DFT) calculations. Moreover, the results of time‐dependent DFT calculations indicate that the absorption band at 476 nm for the 1,4‐diphenylcyclohexane‐1,4‐diyl radical cation corresponds to a SOMO‐3→SOMO transition.
Total Synthesis of Myxovirescin A1
Authors: Fürstner Alois , Bonnekessel Melanie , Blank Jarred T. , Radkowski Karin , Seidel Günter , Lacombe Fabrice , Gabor Barbara , Mynott Richard
Published: September 2007

A convergent total synthesis of the antibiotic macrolide myxovirescin A1 (1) is described that is largely based on reagent‐ and catalyst‐controlled transformations. This includes a highly regioselective Negishi reaction of dibromo‐alkene 48 with an alkynylzinc reagent, and a palladium catalyzed alkyl‐Suzuki coupling of the resulting enyne derivative 12 with the 9‐BBN‐adduct derived from alkene 61. The latter was obtained via an asymmetric hydrogenation of the chlorinated β‐ketoester 49 and an anti‐selective oxyallylation of the functionalized aldehyde 53 as the key steps. The preparation of the bis‐borylated allyl‐donor 57 used in the oxyallylation step, however, required careful optimization and led to important insights into the nature of the classical hydroborating agent “di(isopinocampheyl)borane (Ipc2BH)”. It was unambiguously shown by X‐ray crystallography that in the solid state this compound is dimeric, but it is prone to undergo an essentially quantitative mono‐deborylation when dissolved in CH2Cl2 or benzene; its composition in ethereal solvents is even more complex as evident from 11B NMR data. Product 71 derived from 12 and 61 was elaborated into the enyne–yne derivative 75, which served as the substrate for an exquisitely selective ring closing alkyne metathesis reaction (RCAM) catalyzed by the molybdenum tris‐amido complex 20 activated in situ with CH2Cl2. The resulting cyclic enyne 76 was subjected to a ruthenium catalyzed trans‐hydrosilylation/proto‐desilylation tandem. Although [Cp*Ru(MeCN)3]PF6 had previously been recommended as catalyst of choice for trans‐hydrosilylation reactions of internal alkynes, this complex failed to afford the desired product, whereas its sterically less hindered congener [CpRu(MeCN)3]PF6 permitted the reaction to be performed in appreciable yield, but at the expense of a lower stereoselectivity. AgF‐mediated proto‐desilylation of the isomeric silanes 79 and 80 followed by cleavage of the remaining acetal protecting groups afforded myxovirescin A1 and its hitherto unknown 14Z‐isomer 81, respectively.