bluuebunny/crossref_metadata_2025 huggingface dataset:
“Hidden” Spin–Spin Interactions in Complex Multispin Solids
Authors: Gorelik Elena V. , Ovcharenko Victor I. , Baumgarten Martin
Published: May 2008

A detailed analysis of the electronic structure and magnetic properties of a heterospin network based on a Cu(hfac)2 complex with a nitronyl nitroxide biradical using the broken‐symmetry density functional theory approach is reported. An extremely complex set of exchange parameters was revealed that cannot be obtained from the data of magnetochemical experiments alone. The compensating contributions from various exchange clusters show themselves in a sophisticated combination, and would be “hidden” without an in‐depth quantum chemical investigation. For this purpose the extended network was subdivided into the dominating spin clusters bridged by the organic biradical spacer and each spin system was checked for a consistency of the spin couplings. Fairly large positive and negative exchange couplings in the strongly coupled clusters were found to cancel each other out. Furthermore, the detailed substructure analysis revealed that even in a linearly aligned spin system the next‐nearest‐neighbor interactions can be of the utmost importance and of similar size to that of the direct‐neighbor exchange. Calculated exchange interaction parameters were employed to model the temperature dependence of the effective magnetic moment for the heterospin system under study. The use of PBE0 estimates of exchange interaction parameters yielded a μeff(T) dependence that was in good agreement with the experimental data, which enabled the data to be used as a starting point in the fitting procedure leading to the physical meaningful results.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Lanthanide‐Based Conjugates as Polyvalent Probes for Biological Labeling
Authors: Claudel‐Gillet Stéphanie , Steibel Jérôme , Weibel Nicolas , Chauvin Thomas , Port Marc , Raynal Isabelle , Toth Eva , Ziessel Raymond F. , Charbonnière Loïc J.
Published: May 2008

A series of lanthanide complexes of [LnL(H2O)] composition, suitable for biological labeling has been studied, in which L is a strongly chelating ligand containing chromophoric bipyridylcarboxylate units and Ln = Sm, Eu, Gd, Tb, and Dy. For the Gd complex, a combined 17O NMR and 1H NMRD study has been performed. The water exchange rate obtained, kex298 = (5.2 ± 0.6) × 106 s–1, is slightly higher than those for [Gd(dota)(H2O)]– or [Gd(dtpa)(H2O)]2–. Transformation of the uncoordinated carboxylate function of the ligand into an activated ester ensures covalent linking of the complex to bovine serum albumine (BSA). The relaxivity properties of the Gd complex labeled on BSA revealed a limited increase of both longitudinal and transversal relaxivities. This can be related to the partial replacement of the inner‐sphere water molecules by coordinating functions of the protein. Additionally, the Sm and Dy complexes are described and chemically characterized. Their photophysical properties were investigated by means of absorption, steady‐state and time‐resolved spectroscopy, evidencing efficient photosensitization of the lanthanide emission by ligand excitation (antenna effect). Luminescence lifetime measurements confirmed the presence of a water molecule in the first coordination sphere that partly explained the relatively poor luminescence properties of the Dy and Sm complexes in aqueous solutions. The spectroscopic properties of the series of complexes are questioned in terms of time‐resolved acquisition techniques. Finally, their availability for use in time‐resolved luminescence microscopy is demonstrated by staining experiments of rat brain slices, where the complex showed enhanced localization in some hydrophilic regions of the blood–brain barrier (BBB).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tetra‐tert‐butyltrioxabicyclo[3.3.1]nonadienedicarboxylic Acid: Optical Resolution, Absolute Configuration and Application in Chiral Discrimination
Authors: Kremsner Jennifer , Wallfisch Bianca C. , Belaj Ferdinand , Uray Georg , Kappe C. Oliver , Wentrup Curt , Kollenz Gert
Published: May 2008

The enantiopure bridged bis‐dioxine 4, a dissymmetric dicarboxylic acid exhibiting axial chirality, can easily be synthesized and serve as host for separating and/or transporting chiral guest molecules. Racemic 4 gives with (R)‐ and (S)‐1‐phenylethylamine the corresponding pure diastereomeric salts 7 and 8. The absolut configuration of the diacid 4 in the diastereomeric salt 7 containing (R)‐1‐phenylethylamine was confirmed to be R by X‐ray crystal structure analysis, which also confirmed its concave nature. Release of the acid‐sensitive pure enantiomers (R)‐4 as well as (S)‐4 was achieved conveniently by use of dry flash‐chromatography on silica. The CD spectrum shows a positive Cotton effect of the (S)‐enantiomer at 206 nm. The enantiomeric purity was proved by 1H NMR discrimination of the diastereomeric salts with (R,R)‐1,2‐bis(4‐methoxyphenyl)ethane‐1,2‐diamine as the base. The dicarboxylic acid (R)‐4 can be used as chiral auxiliary as demonstrated by the difficult resolution of racemicN,N′‐di‐tert‐butyl‐1,2‐bis(4‐methoxyphenyl)ethane‐1,2‐diamine 9.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Natural Product Derivatives Containing 2,4‐Concatenated Oxazoles
Authors: Hernández Delia , Riego Estela , Albericio Fernando , Álvarez Mercedes
Published: May 2008

Herein is described the synthesis of several oxazole‐containing derivatives of IB‐01211. The macrocyclization reaction of peptide 14 containing a concatenated triazole was successful and afforded 3 by amide bond formation. However, for those compounds containing quaterazoles or quinqueazoles, the oxazole ring had to be formed during macrocyclization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemical Preparation of Brilliant‐Blue‐Modified Poly(diallyldimethylammonium Chloride) and Nafion‐Coated Glassy Carbon Electrodes and Their Electrocatalytic Behavior Towards Oxygen and L‐Cysteine
Authors: Chen Shen‐Ming , Chen Ji‐Yan , Thangamuthu R.
Published: May 2008

Brilliant blue FCF‐modified glassy carbon electrodes have been prepared by cycling the Nafion (or poly(diallyldimethylammonium chloride) (PDDAC)) coated electrodes repeatedly 15 cycles in brilliant blue FCF (BB FCF) dye solution. The BB FCF molecules are incorporated into Nafion coating by cycling the film‐covered electrode between +0.3 to 1.2 V (vs. Ag/AgCl) in pH 1.5 BB FCF solution while PDDAC‐coated electrode cycled between 0 to −1.0 V (vs. Ag/AgCl) in pH 6.5 BB FCF solution to immobilize the dye. Electrostatic interaction between dye molecule and PDDAC was predominant in PDDAC coating whereas immobilization of dye in Nafion film attributed to the combined effect of electrostatic and hydrophobic interactions. The voltammetric features of BB FCF‐modified electrodes resemble that of surface‐confined redox couples. The peak potentials of BB FCF‐incorporated PDDAC‐coated electrode were shifted to more positive potential region with decreasing pH of contacting solution. BB FCF‐modified electrodes showed electrocatalytic activity towards reduction of oxygen and oxidation of L‐cysteine with significant decease of overvoltage compared to unmodified electrode. The BB FCF‐modified Nafion‐coated electrode was tested for its analytical applications toward determination of L‐cysteine. The linear range of calibration plot at BB FCF‐modified Nafion‐coated electrode is 10 to 100 μM, which coincides with L‐cysteine levels in biological fluids. Sensitivity and detection limit of the electrode are 111 nA μM−1 and 0.5 μM, respectively.
Black and white and read all over: Race differences in reactions to recruitment Web sites
Authors: Goldberg Caren B. , Allen David G.
Published: May 2008

Based on signaling theory, this study examines the impact of Web‐site design and content characteristics on applicants' intentions to pursue employment, the mediating effects of engagement with the Web site and attitude toward the organization, and the moderating effects of applicant race on these relationships. The design characteristics of ease of use and usefulness impact attraction indirectly through Web‐site engagement and attitude toward the organization. Further, Web sites' parasocial interaction (allowance for two‐way communication) predicts intentions to pursue both directly and indirectly through engagement and attitude toward the organization. Unexpectedly, diversity statements did not impact attraction in the full sample. Multigroup analyses revealed that many of the paths between the predictors of parasocial interaction and (to a lesser extent) diversity statements and the outcomes differed by race, with stronger effects observed for blacks than whites. Theoretical and practical implications are discussed. © 2008 Wiley Periodicals, Inc.
Supporting a diverse workforce: What type of support is most meaningful for lesbian and gay employees?
Authors: Huffman Ann H. , Watrous‐Rodriguez Kristen M. , King Eden B.
Published: May 2008

We examine differences in type of support (i.e., supervisor, coworker, organizational) received by lesbian, gay, and bisexual (LGB) employees and the relationship between type of support and relevant outcomes (job and life satisfaction, outness of sexual orientation). Surveys were administered to 99 LGB individuals, and results indicate that support is best viewed as a multi‐dimensional construct composed of supervisor, coworker, and organizational support for LGB employees. Overall, supervisor support was related to job satisfaction, coworker support was related to life satisfaction, and organizational support for LGB employees was related to outness.Thus, support for LGB employees isrelated to important outcomes. Practical suggestions for increasing organizational support for LGB employees are offered. © 2008 Wiley Periodicals, Inc.
Overlooked and underutilized: People with disabilities are an untapped human resource
Authors: Lengnick‐Hall Mark L. , Gaunt Philip M. , Kulkarni Mukta
Published: May 2008

The retirement of baby boomers along with a smaller cohort group of young people replacing them poses a challenge for employers in the future—where will they find the workers they need? One largely untapped source of human resources is people with disabilities (PWDs). Why have employers mostly ignored this large labor pool? This research used a semistructured interview approach with 38 executives across a broad array of industries and geographic regions to examine why employers don't hire PWDs and what they believe can be done to change this situation. Results show that most employers are not very proactive in hiring PWDs and that most employers hold stereotypical beliefs not supported by research evidence. © 2008 Wiley Periodicals, Inc.
Interorganizational formal mentoring: Breaking the concrete ceiling sometimes requires support from the outside
Authors: Murrell Audrey J. , Blake‐Beard Stacy , Porter David M. , Perkins‐Williamson Addie
Published: May 2008

Our research explores the idea that formal mentoring relationships that cut across traditional organizational boundaries may facilitate positive interactions among an increasingly diverse workforce. We present interview, Web‐survey, and focus‐group data across an eight‐month period from a pilot test of an interorganizational formal mentoring (IOFM) program sponsored by the Executive Leadership Council (ELC). Results indicate that IOFM provides valuable access to mentoring relationships that include trust and psychosocial support, access to legitimate organizational power, and the sharing of social capital across traditional organizational boundaries. The benefits and challenges of this approach to mentoring and diversity are examined. © 2008 Wiley Periodicals, Inc.
Making public organizations more inclusive: A case study of the Victoria Police Force
Authors: Metz Isabel , Kulik Carol T.
Published: May 2008

In contrast to traditional models of change developed in the private sector, change in public‐sector organizations often is initiated by noninclusive cultures, and the culture itself is the direct focus of the change effort. This article describes the strategies used by the Chief Commissioner of Police to change the Victoria Police Force's culture to be diversity‐inclusive. We first explain how this change effort used traditional change strategies (e.g., organizational artifacts reflecting the new culture). We then analyze how it differs from traditional change models and explain the role of the broader system, such as legislative support, in the change process. © 2008 Wiley Periodicals, Inc.
Stereo imaging and cytocompatibility of a model dental implant surface formed by direct laser fabrication
Authors: Mangano Carlo , Raspanti Mario , Traini Tonino , Piattelli Adriano , Sammons Rachel
Published: May 2008

Direct laser fabrication (DLF) allows solids with complex geometry to be produced by sintering metal powder particles in a focused laser beam. In this study, 10 Ti6Al4V alloy model dental root implants were obtained by DLF, and surface characterization was carried out using stereo scanning electron microscopy to produce 3D reconstructions. The surfaces were extremely irregular, with ∼100 μm deep, narrow intercommunicating crevices, shallow depressions and deep, rounded pits of widely variable shape and size, showing ample scope for interlocking with the host bone. Roughness parameters were as follows: Rt, 360.8 μm; Rz, 358.4 μm; Ra, 67.4 μm; and Rq, 78.0 μm. Disc specimens produced by DLF with an identically prepared surface were used for biocompatibility studies with rat calvarial osteoblasts: After 9 days, cells had attached and spread on the DLF surface, spanning across the crevices, and voids. Cell density was similar to that on a commercial rough microtextured surface but lower than on commercial smooth machined and smooth‐textured grit‐blasted, acid‐etched surfaces. Human fibrin clot extension on the DLF surface was slightly improved by inorganic acid etching to increase the microroughness. With further refinements, DLF could be an economical means of manufacturing implants from titanium alloys. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Crack initiation processes in acrylic bone cement
Authors: Sinnett‐Jones P. E. , Browne M. , Moffat A. J. , Jeffers J. R. T. , Saffari N. , Buffière J.‐Y. , Sinclair I.
Published: May 2008

A major constraint in improving the understanding of the micromechanics of the fatigue failure process and, hence, in optimizing bone cement performance is found in the uncertainties associated with monitoring the evolution of the internal defects that are believed to dominate in vivo failure. The present study aimed to synthesize high resolution imaging with complementary damage monitoring/detection techniques. As a result, evidence of the chronology of failure has been obtained. The earliest stages of crack initiation have been captured and it is proposed that, in the presence of a pore, crack initiation may occur away from the pore due to the combined influence of pore morphology and the presence of defects within regions of stress concentration. Furthermore, experimental evidence shows that large agglomerations of BaSO4 are subject to microcracking during fatigue, although in the majority of cases, these are not the primary cause of failure. It is proposed that cracks may then remain contained within the agglomerations because of the clamping effect of the matrix during volumetric shrinkage upon curing. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Vascular endothelial cells on two‐and three‐dimensional fibrin assemblies for biomaterial coatings
Authors: Filová Elena , Brynda Eduard , Riedel Tomáš , Bačáková Lucie , Chlupáč Jaroslav , Lisá Věra , Houska Milan , Dyr Jan E.
Published: May 2008

Various techniques for coating synthetic surfaces with fibrin structures were tested for seeding bovine pulmonary artery endothelial cells (EC). Two‐dimensional fibrin (Fb) structures (2D Fb) were obtained by successively repeating adsorption of fibrinogen (Fbg), incubating the surface with thrombin (Thr) solution, and inhibiting surface‐attached Thr. Three‐dimensional fibrin networks immobilized at the surface (3D Fb) were formed by catalytic action of surface‐attached thrombin on an ambient Fbg solution. Ultra‐thin 3D Fbs were obtained if thrombin inhibitors antithrombin III and heparin were added into an Fbg solution. The formation of surface fibrin structures was observed in situ using surface plasmon resonance. The morphology of the structures was studied by transmission and scanning electron microscopy. A polylactide fibrous scaffold was modified with a surface fibrin film without filling the inner pores with a bulk gel. The growth of EC seeded on a polystyrene surface coated with the Fb films was evaluated by the number and morphology of the adhering ECs and the concentration of beta‐actin, vinculin, alphav‐intergrin, and von Willebrand factor (vWF). The best initial cell spreading after 1 day was observed on 2D Fb and ultra‐thin 3D Fb. The highest concentration of vWF, a marker of EC differentiation, was observed after 3 days on thick 3D Fbs. The highest EC population densities after 7 days were observed on 2D Fb and thick 3D Fb. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Optimisation of enzymatic hydrolysis for concentration of squalene in palm fatty acid distillate
Authors: Leng Camilla Chua Soo , Baharin Badlishah Sham , Che Man Yaakob , Tan Chin Ping
Published: May 2008

BACKGROUND: Squalene was concentrated from palm fatty acid distillate (PFAD) in this study using commercial immobilised Candida antarctica lipase (Novozyme 435®). The PFAD was neutralised (NPFAD) using an alkali to liberate the free fatty acids and then hydrolysed at 65 ± 1 °C. The enzymatic hydrolysis on NPFAD was optimised using response surface methodology (RSM) before being neutralised again to obtain a concentrated squalene fraction.

RESULTS: A five‐level, three‐factor central composite rotatable design was adopted to evaluate the effects of the enzymatic hydrolysis parameters reaction time (4–12 h), water content (50–70% w/w) and enzyme concentration (1.5–3.5% w/w) on the percentage yield of squalene concentration. The optimal reaction parameters for maximum yield of squalene concentration were identified from the respective contour plots. The optimal enzymatic hydrolysis conditions were a reaction time of 7.05 h, a water content of 61.40% w/w and an enzyme concentration of 2.23% w/w.

CONCLUSION: RSM was used to determine the optimal conditions for enzymatic hydrolysis of NPFAD with C. antarctica lipase for maximum recovery of squalene which could be implemented on an industrial scale. Copyright © 2008 Society of Chemical Industry
Comparative study of the effects of 1‐MCP treatment on apple quality by instrumental and multivariate analysis
Authors: Larrigaudière Christian , Vilaplana Rosa , Soria Yolanda , Recasens Inmaculada
Published: May 2008

BACKGROUND: The main aim of this work was to define how 1‐methylcyclopropene (1‐MCP) treatment affects apple fruit quality by two complementary approaches.

RESULTS: The results confirmed that 1‐MCP treatment maintained firmness and acidity of the fruit. Multivariate analysis distinguished treated and untreated fruits and showed that a relationship exists between 1‐MCP treatment and firmness, and also between 1‐MCP and the physiological disorder, ‘diffuse skin browning’ (DSB). Relationships for acidity were low and absent for soluble‐solids concentration (SSC). The PCA model built only with 1‐MCP treated fruit showed a positive correlation between DSB incidence and firmness, and a negative correlation between DSB and SSC or a* values. Collectively, these correlations indicated that the more immature fruits are more susceptible to DSB. This last model also characterised acidity as the best parameter to discriminate the 1‐MCP fruits.

CONCLUSION: It is the first time that such a comparative study has been conducted on 1‐MCP treated fruits. The results are of interest because they (1) help to discriminate treated and untreated fruits, and (2) allow discrimination of 1‐MCP‐treated fruit during storage. Copyright © 2008 Society of Chemical Industry
Possible heat‐tolerant wheat cultivar improvement through the use of flag leaf gas exchange traits in a Mediterranean environment
Authors: Koç Müjde , Barutçular Celaleddin , Tiryakioǧlu Murat
Published: May 2008

BACKGROUND: Flag leaf traits are associated with performance of wheat (Triticum aestivum L.) genotypes in heat‐stress environments. Fifteen cultivars were evaluated during 3 years with two sowing dates under irrigated conditions so as to examine the relationship between the flag leaf traits and performance in a Mediterranean environment.

RESULTS: It became possible to assess a heat susceptibility index (HSI) for each cultivar by altering the sowing date, exposing the crops to different temperatures. The cultivars showed significant differences for all measured traits except canopy temperatures and chlorophyll fluorescence, though not all were consistent. Excluding two cultivars that differed in development, yield, grain number, harvest index and leaf An (net CO2 assimilation rate), gs (stomatal conductance to water vapor), mc (apparent mesophyll conductance of CO2) and ash content were negatively associated with HSI, whereas leaf area and width were positively associated. Traits showing the best correlation with HSI were An, followed by area, gs, mc, width and ash content. High An was associated with smaller leaf size.

CONCLUSION: It is worthwhile to select high ear grain number and harvest index. In addition, flag leaf gas exchange traits and ash content can be used as complementary selection criteria after the possible pleiotropic associations of these traits with leaf size are clarified. Copyright © 2008 Society of Chemical Industry
Isolation and characterization of degradation products of citalopram and process‐related impurities using RP‐HPLC
Authors: Rao Ramisetti Nageswara , Raju Ale Narasa , Narsimha Ramaram
Published: May 2008

A reversed‐phase high‐performance liquid chromatographic method for simultaneous separation and determination of citalopram hydrobromide and its process impurities in bulk drugs and pharmaceutical formulations was developed. The separation was accomplished on an Inertsil ODS 3V (250×4.6 mm; particle size 5 μm) column using 0.3% diethylamine (pH = 4.70) and methanol/acetonitrile (55:45 v/v) as mobile phase in a gradient elution mode. The eluents were monitored by a photodiode array detector set at 225 nm. The chromatographic behavior of all the related substances was examined under variable conditions of different solvents, buffer concentrations, and pH. The method was validated in terms of accuracy, precision, and linearity. The method could be of use not only for rapid and routine evaluation of the quality of citalopram in bulk drug manufacturing units but also for the detection of its impurities in pharmaceutical formulations. Three unknown impurities were consistently observed during the analysis of different batches of citalopram. Forced degradation of citalopram was carried out under thermal, photo, acidic, alkaline, and peroxide conditions. The degradation products and unknown impurities were isolated and characterized by ESI‐MS/MS, 1H NMR, and FT‐IR spectroscopy.
Single‐step approach to β‐cyclodextrin‐bonded silica as monolithic stationary phases for CEC
Authors: Hsieh Ming‐Lung , Li Guan‐Yi , Chau Lai‐Kwan , Hon Yung‐Son
Published: May 2008

A novel single‐step sol–gel approach for the preparation of β‐CD‐bonded silica monolithic electrochromatographic columns is established. The porous silica networks were fabricated inside fused‐silica capillaries using sol–gel processing of tetramethoxysilane and an organfunctional silicon alkoxide that contains β‐CD. Scanning electron micrographs and nitrogen adsorption–desorption data showed that these functional monolithic columns have double pores structures with micrometer‐size co‐continuous through‐pores and silica skeletons with open mesopores. The β‐CD monolithic columns have successfully been applied to the separation of several neutral and negatively charged isomers by CEC. The column performance was evaluated by using positional isomers of naphthalenedisulfonic acid as model compounds. A plate height of less than 10 μm for the first eluted isomer of naphthalenedisulfonic acid was obtained at an optimal flow rate (0.47 mm/s) of the mobile phase. Moreover, the columns have been proved to be stable for more than 100 runs during 3 months period and show reasonable column reproducibility.
A method to test the detectability of GC/PFPD for an extended concentration range with respect to reduced sulfur compounds
Authors: Kim Ki‐Hyun
Published: May 2008

In this study, a possible means to extensively expand the quantifiable range of reduced sulfur compounds (RSC) in air has been investigated by a combined application of GC with pulsed flame photometric detector (PFPD) and a multifunction thermal desorber (TD) system. To comply with the purpose of this study, gaseous RSC standards containing the equimolar concentrations of H2S, CH3SH, DMS, DMDS, and CS2 were prepared at 11 concentration levels (i. e., 10 ppb–10 ppm (over 103 range)). These standards were then used to derive three‐point calibrations based on the modified injection through a TD (MITD). If the mean calibration slopes of each concentration level are normalized to that of CH3SH, the relative ordering is found as 0.65 (H2S): 1 (CH3SH): 1.34 (DMS): 2.24 (DMDS). The reproducibility of MITD method, when assessed in terms of relative standard error (RSE) for all calibration slopes, had the most stable pattern for DMDS (5.77%) and the least stable one for H2S (12.8%). The sensitivity of the MITD‐based calibration generally improved with an increase in concentration levels of standard gas. Based on our study, the MITD technique is useful to extend quantification of GC/PFPD by allowing RSC detection over a 103 range.
Stereoselective Complex Formation between Polybutadiene and Cyclodextrins in Bulk
Authors: Kuratomi Yukari , Osaki Motofumi , Takashima Yoshinori , Yamaguchi Hiroyasu , Harada Akira
Published: May 2008

Polybutadienes (PBs) are found to form inclusion complexes with cyclodextrins (CDs) stereoselectively to give crystalline compounds in bulk. These complexes have been isolated and characterized by means of 1H NMR and 13C CP/MAS NMR spectroscopy, and X‐ray diffraction. Although α‐CD did not form inclusion complexes with any kinds of PBs in aqueous solutions, α‐CD did form inclusion complexes with PBs having 1,4‐cis‐ and 1,4‐trans‐butadiene units in bulk by heating at 100 °C. On the other hand, PB having 79% of a 1,2‐structure did not form inclusion complexes with α‐CD. The yield of the inclusion complexes increases with an increase in the content of the 1,4‐cis‐structure of PB and decreases with the molecular weights of the PBs.

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Macromol. Rapid Commun. 10/2008
Authors: Schwab Leendert W. , Kroon Renee , Schouten Arend Jan , Loos Katja
Published: May 2008

Cover: The cover picture shows the acyl‐enzyme intermediate formed between 2‐azetidinone and Candida antarctica lipase B derived via docking with subsequent combined QM/MM geometry optimization. The enzyme‐catalyzed ring‐opening polymerization of 2‐azetidinone proceeds via this intermediate. It is shown that poly(β‐alanine) can be prepared by enzyme catalysis and that the ring structure of the 2‐azetidinone is essential for the formation of the acyl‐enzyme intermediate. Further details can be found in the article by L. W. Schwab, R. Kroon, A. J. Schouten, and K. Loos* on page 794 L. Haller and G. Fels, University of Paderborn, are acknowledged for the design of the cover.
Human intestinal hydrolysis of phenol glycosides – a study with quercetin and p‐nitrophenol glycosides using ileostomy fluid
Authors: Knaup Bastian , Kahle Kathrin , Erk Thomas , Valotis Anagnostis , Scheppach Wolfgang , Schreier Peter , Richling Elke
Published: May 2008

In order to study the influence of sugar moiety, aglycon structure and microflora concentration on the human ileal hydrolysis of phenol glycosides, various quercetin and p‐nitrophenol glycosides were incubated under anaerobic conditions (37°C for 0, 0.5, 1, 2, 4, 6, 8, 10 and 24 h) with ileostomy fluids from three different donors. The glycosides, i.e. β‐D‐glucopyranosides, β‐D‐galactopyranosides, α‐L‐arabinofuranosides, β‐D‐xylopyranosides and α‐L‐rhamnopyranosides as well as the liberated aglycones were identified by HPLC‐DAD and HPLC‐ESI‐MS/MS. Among the quercetin glycosides under study, the 3‐O‐β‐D‐glucopyranoside showed with 0.22 μmol/h the highest hydrolysis rate, followed by the 3‐O‐β‐D‐galactopyranoside, the 3‐O‐β‐D‐xylopyranoside and the 3‐O‐α‐L‐arabinofuranoside (0.04 and each 0.03 μmol/h, respectively). Quercetin 3‐O‐α‐L‐rhamnopyranoside was found to be stable for the entire incubation period. Using quercetin 3‐O‐β‐D‐glucopyranoside as a representative example, linear hydrolysis rate was observed from 75 to 2500 μL ileostomy fluid corresponding to its microflora content (log 0.68 up to 21.9 colony forming units). Studies performed in the presence of antibiotics did not reveal any hydrolysis. The p‐nitrophenol glycosides were hydrolyzed faster than the corresponding quercetin glycosides. The hydrolysis rate decreased from the β‐D‐glucopyranoside (0.41 μmol/h), to the β‐D‐galactopyranoside (0.21 μmol/h), the β‐D‐xylopyranoside (0.12 μmol/h), the α‐L‐arabinofuranoside (0.09 μmol/h) to the α‐L‐rhamnopyranoside (0.06 μmol/h). These results demonstrate that the human ileal hydrolysis of phenol glycosides depends on the sugar and the aglycon structure as well as the microflora.
Detection of the administration of 17β‐nortestosterone in boars by gas chromatography/mass spectrometry
Authors: Ventura Rosa , Roig Meritxell , Pérez Belén , López Sergi , Medina Mireia , Bosch Jaume , Segura Jordi
Published: May 2008

17β‐Nortestosterone (17βN) is illegally used in livestock as a growth promoter and its endogenous production has been described in some animals, such as adult boars. In this paper, the metabolism of 17βN in boars has been studied by gas chromatography/mass spectrometry (GC/MS) in order to identify markers of the exogenous administration. Administration studies of intramuscular 17βN laurate to male pigs were performed. Free, sulphate and glucuronide fractions of the urine samples were separated and the steroids present were quantified by GC/MS. 17βN was detected in some pre‐administration samples. After administration, 17βN, norandrosterone, noretiocholanolone (NorE), norepiandrosterone, 5β‐estrane‐3α,17β‐diol and 5α‐estrane‐3β,17β‐diol were detected in different fractions, being the most important metabolites, 17βN excreted as a sulphate and free NorE. Samples collected in routine controls were also analyzed by GC/MS to identify endogenous compounds. 17βN, norandrostenedione and estrone were detected in almost all the samples. No other 17βN metabolites were detected. According to these results, the detection by GC/MS of some of the 17βN metabolites described above, different from 17βN, could be indicative of the exogenous administration of 17βN to boars. Copyright © 2008 John Wiley & Sons, Ltd.
Less hashing, same performance: Building a better Bloom filter
Authors: Kirsch Adam , Mitzenmacher Michael
Published: May 2008

A standard technique from the hashing literature is to use two hash functionsh1(x) andh2(x) to simulate additional hash functions of the formgi(x) =h1(x) +ih2(x). We demonstrate that this technique can be usefully applied to Bloom filters and related data structures. Specifically, only two hash functions are necessary to effectively implement a Bloom filter without any loss in the asymptotic false positive probability. This leads to less computation and potentially less need for randomness in practice. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Increasing accuracy of antenatal ultrasound diagnosis of cleft lip with or without cleft palate, in cases referred to the North Thames London Region
Authors: Demircioglu M. , Kangesu L. , Ismail A. , Lake E. , Hughes J. , Wright S. , Sommerlad B. C.
Published: May 2008

Objectives

To determine the accuracy of antenatal ultrasound diagnosis of cleft lip with or without cleft palate (CL ± P) and isolated cleft palate (CP).

Methods

This was a retrospective review of 256 surviving cases referred in 2002–2003 for treatment of CL ± P.

Results

We had referrals from 36 maternity units, 27 of which were in our local catchment area. There were 154 cases of CL ± P, of which five had microform CL. Of the remaining 149, 88 (59%) were diagnosed on antenatal ultrasound examination. Among these 88 cases there were minor reporting errors in 22 (25%). These errors were in describing the side and type of the lip cleft in 10 cases, predicting if there was a CP in 10 cases, and recognizing the anomaly in two cases. There were 102 cases referred with isolated CP, of which 92 had overt CP and 10 submucous CP. None of these was diagnosed by antenatal ultrasound imaging. There was no significant difference in the accuracy of ultrasound diagnosis between district hospitals and teaching/tertiary units.

Conclusions

There is a good awareness and ability to detect CL ± P by obstetric units from which referrals are received. Inaccuracies in antenatal ultrasound reports occur frequently when attempting to determine the type of CL and when predicting if there is a CP. We recommend that families should continue to be referred to specialist centers for counseling immediately after antenatal diagnosis, and comprehensive advice should always be given about clefts of the lip and palate. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
X‐ray fluorescence analysis of sludge ash from sewage disposal plant
Authors: Ohbuchi Atsushi , Sakamoto Junichi , Kitano Masaru , Nakamura Toshihiro
Published: May 2008

Glass bead/x‐ray fluorescence spectrometry of the sludge incineration ashes generated in sewage processing was developed for the determination of ten major components (Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3) and five minor elements (Zn, Cu, Cr, As, Pb). Sewage sludge ashes consisted of rock‐forming minerals and phosphate crystals that had been used for phosphorus removal. Ash samples were melted and molded with lithium tetraborate to 35 mm diameter glass disks in a Pt–Au crucible. Analytical results of ten major components and five minor elements agreed well with the recommended values of a phosphate rock standard reference material (NIST SRM 694). Elemental compositions of sewage sludge ash from seven sewage‐processing plants in Japan were determined using this method. Concentrations of Fe2O3, SiO2, and CaO, along with loss of ignition in sewage sludge ash mutually differed among the sewage‐processing plant products. Seasonal variations in concentrations of ten major components and five minor components of ash samples produced from October 2001 to September 2002 were determined using the proposed method. Concentrations of SiO2increased with the inflow of gravel by rainfall, thereby decreasing concentrations of P2O5 originating from excreta and microorganisms. Copyright © 2008 John Wiley & Sons, Ltd.
Pearl bodies of Cayratia japonica (Thunb.) Gagnep. (Vitaceae) as alternative food for a predatory mite Euseius sojaensis (Ehara) (Acari: Phytoseiidae)
Authors: Ozawa Mayuko , Yano Shuichi
Published: May 2008

On the young leaves, shoots, and buds of Cayratia japonica (Thunb.) Gagnep. (Vitaceae), we observed nutritious bodies called pearl bodies and hypothesized that they are utilized by generalist predators as alternative foods. Some ambulate organisms consume pearl bodies in the wild and the predatory mite Euseius sojaensis (Ehara) (Acari: Phytoseiidae) was considered as a primary candidate. Pearl bodies promoted E. sojaensis settlement on C. japonica leaves and E. sojaensis could prey on the phytophagous mite Tetranychus kanzawai Kishida (Acari: Tetranychidae) when the predators settle on a leaf before the prey. In addition, the presence of pearl bodies did not reduce predation of E. sojaensis on T. kanzawai. This was seemingly because food quality of T. kanzawai was higher than pearl bodies. These results implied that pearl bodies on C. japonica leaves are utilized by E. sojaensis as alternative foods.
Blind Faith and Political Rationalism in Sophocles' Oedipus at Colonus
Authors: Ahrensdorf Peter J.
Published: May 2008

Political conflicts around the world increasingly reflect a religious challenge to liberal rationalism. Given the tendency of modern political rationalism to underestimate the power of religion, it seems reasonable to consider the classical analysis of religious antirationalism set forth with great clarity in Sophocles' Oedipus at Colonus. The play seeks to demonstrate that religious antirationalism—as exemplified by Oedipus—is self-contradictory and self-destructive, but also that it is rooted in such enduring human traits as our awareness of our mortality, our hope for immortality, and our angry refusal to accept our mortality. Sophocles advocates a sober and cautious political rationalism that recognizes the dangers of religious passion to political life, but also the permanence of religious passion within political life. Such a political rationalism, embodied by Theseus, constitutes a middle way between a blind piety which rejects reason and an excessively hopeful political rationalism which underestimates the power of religion.
The Emancipation of the American Mind: J.S. Mill on the Civil War
Authors: Compton John W.
Published: May 2008

Scholars have generally traced J.S. Mill's interest in the United States to the commercial and democratic aspects of American society. Yet Mill also suggested a third respect in which America was unique: it was the only existing nation founded on the basis of “abstract principles.” This insight provides the key to a fuller understanding of Mill's various writings on America. In his early essays, Mill worried that America's founding principles and institutions were beginning to take on the characteristics of dogma: they were universally accepted, but no longer discussed. Mill responded optimistically to the Civil War because he believed the struggle to extinguish slavery would ultimately restore the meaning or vitality of the founding principles of liberty and equality. With the nation thus “regenerated,” Mill predicted that Americans would soon recognize and address other illiberal aspects of American society, including the subordinate status of women.
Bricks and Stones: A Reply to Paul Franco
Authors: Abbey Ruth
Published: May 2008

Because these books have not received as much scholarly attention as Nietzsche's other writings, Paul Franco's article “Nietzsche's Human, All Too Human and the Problem of Culture” should be welcomed by students of Nietzsche. However, Franco fails to take advantage of the opportunity to really engage with the small secondary literature and move the debate about the significance of these neglected works forward. While Franco mentions most of the other works on Human, All Too Human (henceforth, HH), he barely interacts with what those who have gone before him have said. His decision not to heap “stone upon stone, brick upon brick” (as Nietzsche recommends) is problematic for three related reasons. It (1) forfeits the opportunity to build on what exists—either by affirming, correcting, or adding to the secondary literature in one area of Nietzsche studies where this is possible; (2) makes it impossible for readers to assess the originality of Franco's contribution; and (3) fails readers who should be able to rely upon reputable scholarly writings as fair and faithful guides to the literature on Nietzsche.
Reflections on Rawls
Authors: Young Shaun P.
Published: May 2008

Arguably, there have been few contemporary political theorists who have had as great an impact as John Rawls. During his lifetime his work was referred to as “epoch-making” and “cataclysmic in its effect” on the field of political theory. On numerous occasions he was proclaimed “the most important political philosopher of the twentieth century,” and other titles equally celebratory. A number of individuals have gone so far as to credit Rawls with reviving political philosophy, breathing new life into what was (according to Peter Laslett's now famous 1956 declaration) a dead discipline, once again making it a valid and valuable enterprise. While the accuracy of such a claim has been questioned, one fact seems indisputable: Rawls redefined late twentieth-century political theory, altering its “premises and principles.” Indeed, “political philosophy since the early 1970s has been—at least in the English-speaking world—in very substantial part a commentary on Rawls's work.”
Introduction: Labor in a Changing China
Authors: Yu Renqiu
Published: May 2008

The experiences of the Chinese workers illustrate most dramatically the profound changes taking place in contemporary China. No longer the “leading class” in a socialist country, as proclaimed in the Constitution, many of them, especially the migrant workers from rural areas and the retired, the laid-off, the new urban poor, and farmers, are now reduced to being “the weak groups.” They are voiceless and defenseless, the most vulnerable and desperate people in a society that is rapidly transforming itself through marketization and globalization.
Hidden Forms of Bargaining on China's Shop Floor
Authors: Zhang Xiaodan
Published: May 2008

This article examines shop-floor bargaining in China in both the socialist and reform eras. Based on ethnographic fieldwork conducted in three manufacturing factories, document analysis, and secondary sources, the author discusses how government policies and organizational structure shape the interaction between workshop managers and workers and how the practice on the shop floor alters managerial attempts in return. The author argues that, despite different economic structures in the two historical periods, Chinese workers are not the docile labor force often portrayed in literature and media. Instead, they utilize any leverage given within organizational structures and bargain for not only economic gains, but also for respect and autonomy. Their bargaining, though different from institutionalized union bargaining, influences managerial decisionmaking in a subtle way with ideological implications.
A numerical method for coupled surface and grain boundary motion
Authors: PAN ZHENGUO , WETTON BRIAN
Published: May 2008

We study the coupled surface and grain boundary motion in a bi-crystal in the context of the ‘quarter loop’ geometry. Two types of normal curve velocities are involved in this model: motion by mean curvature and motion by surface diffusion. Three curves meet at points where junction conditions are given. A formulation that describes the coupled normal motion of the curves and preserves arc length parametrisation up to scaling is proposed. The formulation is shown to be well-posed in a simple, linear setting. Equations and junction conditions are approximated by finite difference methods. Numerical convergence to exact travelling wave solutions is shown. The method is applied to other problems of physical interest.
From the News and Commentary Editor
Authors: Reine Barbara A
Published: May 2008

This issue brings my first full year as editor of the News and Commentary to a close—a year of evolution from “making up it as we go along” to a position where there are regular features that provide consistency and a theme to the News and Commentary. The Calendar of Meetings and Courses continues. Most notable has been the introduction of a feature entitled “The Life and Achievements of …” in which such scientists as Albert Prebus, John Reisner, and Raymond Castaing have been profiled by individuals who knew them and who have generously agreed to write about them. This feature will be continued and any suggestions for individuals to be profiled are welcome.
XIV International Congress on Electron Microscopy Photomicrograph Exhibit
Authors: Reine Barbara A
Published: May 2008

The 14th and last International Congress of Electron Microscopy (ICEM) of the century was held in Cancun, Mexico on August 31-September 4, 1998 under the chairmanship of Dr. Miguel José Yacaman. Held every 4 years in a different international location, these ICEMs are renowned for the science presented, the state-of-the-art instrumentation exhibited, and the mix of international scientists in attendance. They are also made memorable by the unique scientific and cultural contributions from the host country. This Congress was no exception and the 14th ICEM in Cancun, Mexico, characterized by all of these features, was further augmented by the intrinsic beauty and archaeological interest of the Yucatan Peninsula region.
Impact of Energy-Dispersive Spectrometry in Materials Science Microanalysis
Authors: Williams David B
Published: May 2008

X-ray microanalysis of materials using energy-dispersive spectrometry (EDS) has made the greatest impact in studies of compositional changes at atomic-level interfaces. The small physical dimensions of the silicon detector make EDS the X-ray analyzer of choice for analytical transmission electron microscopy (AEM). X-ray analysis of thin foils in the AEM has contributed to our understanding of elemental segregation to interphase interfaces and grain boundaries, as well as other planar defects. Measurement of atomic diffusion on a small scale close to interphase interfaces has permitted determination of substitutional atomic diffusivities several orders of magnitude smaller than previously possible and has also led to the determination of low-temperature equilibrium phase diagrams through the measurement of local interface compositions. Elemental segregation to grain boundaries is responsible for such deleterious behavior as temper embrittlement, stress-corrosion cracking, and other forms of intergranular failure. On the other hand, segregation can bring about improvement in behavior: sintering aids in ceramics and de-embrittlement of intermetallics. EDS in the AEM has been responsible for quantitative analysis of all aspects of the segregation process and, more recently, in combination with electron energy-loss spectrometry (EELS) has given insight into why boundary segregation results in such significant macroscopic changes in properties.
Application of X-ray Optics to Energy-Dispersive Spectroscopy
Authors: McCarthy Jon J , McMillan David J
Published: May 2008

X-ray optics have been used in X-ray analytical instruments for several years. Applications of X-ray optics have been reported in X-ray diffraction, X-ray fluorescence, and wavelength dispersive spectroscopy. X-ray optics have been used to increase the X-ray flux incident on the sample or to direct and focus emitted X-rays from a sample. We report here the use of a grazing incidence optic (GIO) as a flux-enhancing collimator for use with an energy-dispersive (ED) detector used to perform electron beam microanalysis. We found that the GIO in combination with an ED spectrometer (EDS) provides substantial intensity gain for X-ray lines with energy below 1 keV. The GIO is also found to provide a modest focus effect, and introduces minimal spectral artifacts.