bluuebunny/crossref_metadata_2025 huggingface dataset:
Conformity in diversity? Isotopic investigations of infant feeding practices in two iron age populations from Southern Öland, Sweden
Authors: Howcroft Rachel , Eriksson Gunilla , Lidén Kerstin
Published: July 2012

This article presents the results of a study of infant diet at two Iron Age sites on the island of Öland, Sweden. The cemetery at Bjärby contained a large number of subadults who had survived the earliest years of life, whereas most individuals at Triberga had died by 6 months of age. To investigate whether differences in infant feeding could explain the different mortality rates, the carbon, nitrogen, and sulfur stable isotope ratios of bone and tooth dentin collagen from the two sites were analyzed. Twenty‐two samples from Triberga and 102 from Bjärby yielded data that could be included in the carbon and nitrogen analysis. Twelve samples from Triberga and 42 from Bjärby were included in the sulfur analysis. The results for carbon (δ13C: Triberga X = –18.8, s.d. = 1.1; Bjärby X = –19.8, s.d. = 0.4), nitrogen (δ15N: Triberga X = 12.9, s.d. = 1.5; Bjärby X = 13.4, s.d. = 1.4), and sulfur (δ34S: Triberga X = 8.1, s.d. = 1.1; Bjärby X = 5.8, s.d. = 1.3) suggest that diet was broadly similar at both sites and based on terrestrial resources. At Bjärby, females and high‐status individuals consumed higher‐trophic level protein than other males from early childhood onward. There was some indication that the contribution of marine resources to the diet may also have differed between the sexes at Triberga. No consistent differences in breast milk intake were observed between the two sites, but there was substantial variation at each. This variation may reflect an influence of gender and social status on infant feeding decisions. Am J Phys Anthropol 149:217–230, 2012. © 2012 Wiley Periodicals, Inc.
Brief communication: Prenatal and early postnatal stress exposure influences long bone length in adult rat offspring
Authors: Dancause Kelsey Needham , Cao Xiu Jing , Veru Franz , Xu Susan , Long Hong , Yu Chunbo , Laplante David P. , Walker Claire Dominique , King Suzanne
Published: July 2012

Stress during the prenatal and early postnatal periods (perinatal stress, PS) is known to impact offspring cognitive, behavioral, and physical development, but effects on skeletal growth are not clear. Our objective was to analyze effects of variable, mild, daily PS exposure on adult offspring long bone length. Twelve pregnant rat dams were randomly assigned to receive variable stress from gestational days 14–21 (Prenatal group), postpartum days 2–9 (Postnatal), both periods (Pre–Post), or no stress (Control). Differences in adult offspring tibia and femur length were analyzed among treatment groups. Mean tibia length differed among groups for males (P = 0.016) and females (P = 0.009), and differences for femur length approached significance for males (P = 0.051). Long bone length was shorter among PS‐exposed offspring, especially those exposed to postnatal stress (Postnatal and Pre–Post groups). Results persisted when controlling for nose–tail length. These differences might reflect early stunting that is maintained in adulthood, or delayed growth among PS‐exposed offspring. This study suggests that PS results in shorter long bones in adulthood, independently of effects on overall body size. Stunting and growth retardation are major global health burdens. Our study adds to a growing body of evidence suggesting that PS is a risk factor for poor linear growth. Am J Phys Anthropol 149:307–311, 2012. © 2012 Wiley Periodicals, Inc.
Brief communication: The human humerus from the Broken Hill Mine, Kabwe, Zambia
Authors: Trinkaus Erik
Published: July 2012

The distal half of a right human humerus (E.898), recovered ex situ in 1925 by Hrdlička at the Broken Hill Mine, Kabwe, Zambia, has figured prominently in assessments of Middle Pleistocene Homo postcranial variation and of the phylogenetic polarity and functional anatomy of Pleistocene Homo upper limb morphology. Reassessment of distal humeral features that distinguish modern human and some archaic Homo humeri, especially relative olecranon breadth and medial and lateral pillar thicknesses, confirm previous studies placing it morphologically close to recent humans, as well as possibly to Early Pleistocene Homo. However, it completely lacks stratigraphic context, and there is faunal and archeological evidence for human activity at Broken Hill from the Middle Pleistocene to the Holocene. Given its uncertain geological age and modern human morphology, the Broken Hill E.898 humerus should not be used in analyses of Pleistocene humans until it is securely dated. Am J Phys Anthropol 149:312–317, 2012. © 2012 Wiley Periodicals, Inc.
Lichtgesteuerte Werkzeuge
Authors: Brieke Clara , Rohrbach Falk , Gottschalk Alexander , Mayer Günter , Heckel Alexander
Published: July 2012

Die zeitliche und räumliche Kontrolle über chemische und biologische Prozesse spielt eine Schlüsselrolle im Leben, wo das Ganze oft viel mehr ist als die Summe seiner Einzelteile. Trivialerweise bilden die Moleküle einer Zelle noch lange kein lebendiges System aus, wenn sie lediglich willkürlich angeordnet werden. Wenn wir diese Zusammenhänge und die Probleme, die durch Fehlfunktionen entstehen, verstehen wollen, benötigen wir Werkzeuge, mit denen wir komplexe Experimente für diese Fragestellungen entwickeln können. Externe Triggersignale, mit denen wir präzise bestimmen können, wo, wann und in welchem Ausmaß ein Prozess gestartet oder gestoppt wird, sind dafür äußerst wertvoll. Licht ist solch ein ideales Triggersignal: Es ist hoch selektiv und bei richtiger Anwendung unschädlich. Es kann mit gut etablierten Techniken erzeugt und manipuliert werden, und viele Ansätze existieren, um Licht in lebenden Systemen anzuwenden – von Zellen bis zu höheren Organismen. Dieser Aufsatz wird sich mit den aktuellen Entwicklungen der letzten sechs Jahre befassen und die zugrundeliegenden Technologien sowie ihre Anwendungen diskutieren.
Light‐Controlled Tools
Authors: Brieke Clara , Rohrbach Falk , Gottschalk Alexander , Mayer Günter , Heckel Alexander
Published: July 2012

Spatial and temporal control over chemical and biological processes plays a key role in life, where the whole is often much more than the sum of its parts. Quite trivially, the molecules of a cell do not form a living system if they are only arranged in a random fashion. If we want to understand these relationships and especially the problems arising from malfunction, tools are necessary that allow us to design sophisticated experiments that address these questions. Highly valuable in this respect are external triggers that enable us to precisely determine where, when, and to what extent a process is started or stopped. Light is an ideal external trigger: It is highly selective and if applied correctly also harmless. It can be generated and manipulated with well‐established techniques, and many ways exist to apply light to living systems—from cells to higher organisms. This Review will focus on developments over the last six years and includes discussions on the underlying technologies as well as their applications.
Surface immobilization of Rhizopus oryzae (ATCC 96382) for enhanced production of lipase enzyme by multiple responses optimization
Authors: Potumarthi Ravichandra , Liu Jacques , Wan Harry , Danquah Michael
Published: July 2012

A modified Response Surface Methodology was used for the optimization of lipase production by immobilized cells of Rhizopus oryzae (ATCC 96382). Multiple responses optimization strategy was adopted to optimize process condition of surface immobilization technique for the optimization of lipase productivity. Five parameters, pH, Temperature, revolutions per minute, olive oil and glucose were considered, and their effect was evaluated both qualitatively and quantitatively by using a modified central composite design approach and model validation. The second order regression equation was developed for the three yield parameters are YP/B, YL/P and YL/B, where Y is the yield parameter at their corresponding values of L: Lipase (U/mL), P: Protein (mg/mL) and B: Biomass (mg/mL). The regression equation was fitted and model fit (R2) was 0.604 (YP/B), 0.746 (YL/P) and 0.618 (YL/B), respectively showing an effective fit. Further, the model was validated theoretically and experimentally at higher level of production. Different growth patterns were observed during 120 h of fermentation period. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Bioplastics from renewable resources: the benefits of biodegradability
Authors: Razza Francesco , Innocenti Francesco Degli
Published: July 2012

Bioplastics made with renewable resources are now ready for full commercial exploitation. Starch‐based plastics are an important class of bioplastics used to make biodegradable products. Biodegradability can contribute to alleviating the waste problem of our current society. In this paper, three case studies based on the use of starch‐based plastics are shown. Biodegradable products can both reduce the amount of waste produced and increase material recycling and landfill diversion. The products analysed and the main effects of shifting towards biodegradable plastics are examined next. By using biodegradable mulch film, waste passes from 400 up to ≈ 0 kg per mulched hectare. By using biodegradable catering items, the average recycling (including organic recycling) rate increases from ≈ 0 up to 50% whereas landfill diversion increases by 36% on average across EU‐27. By shifting towards biodegradable carrier bags, a substantial reduction of contaminants present in bio‐waste and screened off by composting plants results in an almost fivefold increase of bio‐waste quality. The possibility of shifting from heterogeneous waste (non‐biodegradable plastics + bio‐waste) into homogeneous waste (biodegradable plastics + bio‐waste) makes the use of bioplastics particularly beneficial for the waste management ecoprofile as shown by previous life cycle assessment studies available in literature. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of 4,4′‐methylenediphenyl diisocyanate on thermal and mechanical properties of Bioflex/lactic acid polycondensate blends
Authors: Gregorova A. , Riedl E. , Sedlarik V. , Stelzer F.
Published: July 2012

Polylactic acid as thermoplastic aliphatic polyester has attracted much attention because of its renewability and biodegradability. The current work investigates the influence of 4,4′‐methylenediphenyl diisocyanate (MDI) on thermal and mechanical properties of Bioflex/lactic acid polycondensate blends. Bioflex is a commercial product based on polylactic acid and a thermoplastic copolyester. Lactic acid polycondensate (polylactide) was obtained by direct melt polycondensation of lactic acid in the presence of stannous octoate as the catalyst. The increase in molecular weights (size exclusion chromatography) and the improved mechanical properties (stress–strain analysis) revealed that MDI under reactive extrusion conditions effectively adjusted the compatibility of Bioflex with 10 wt% of polylactide. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Separation of polydisperse particle mixtures by deterministic lateral displacement. The impact of particle diffusivity on separation efficiency
Authors: Cerbelli S.
Published: July 2012

Deterministic lateral displacement (DLD) has been recently proposed as a simple and efficient method to separate a polydisperse mixture of particles based on particle size. The separation device consists of a shallow rectangular channel filled with a periodic lattice of micrometer‐sized obstacles, whose principal direction forms an angle with the channel walls. Particles are dragged by a carrier flow stream through the device. Experiments have shown that particles larger than a critical size depart from the average direction of the carrier flow, as they are systematically deflected by the obstacles while being dragged downstream. Theoretical models based on the geometric structure of the Stokes flow through the obstacle lattice have been proposed to predict the average direction of particle current flux. Besides, little is known about the dispersion of diffusing particles about the average particle current. In this article, we show that the interaction between the deterministic and stochastic components of particle motion results in a large‐scale, possibly anisotropic, convection‐enhanced dispersion process, which may hinder separation far beyond what could be predicted from the value of the bare particle diffusivity. The prediction of dispersion regimes results therefore essential for an optimal design of DLD devices. Copyright © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Development of a modified differential biofiltration reactor with online sample and carbon dioxide monitoring system
Authors: Detchanamurthy Swaminathan , Gostomski Peter Alan
Published: July 2012

Biofiltration is one of the air pollution control technologies (APCTs) used widely in treating the odorous and volatile organic compounds (VOCs). Reliability and robustness in measuring the pollutant degradation rate and carbon dioxide production is considered most important in a biofiltration system. In this current work, a gas chromatography (GC) system and carbon dioxide analyser were introduced online to a lab scale differential biofiltration reactor with water content control. Toluene, one of the potential VOCs, was used as a model pollutant in our current study. The feasibility and limitations of online GC and CO2 analyzer was evaluated by measuring the inlet and outlet toluene concentrations along with CO2 concentrations and compared with the regular offline measurements. Furthermore, a simple diffusion system was proposed and used in the current work to improve the robustness of toluene vapour production. The results indicate that the modifications carried out in the lab scale biofiltration reactor and in the diffusion system improved the data collection and stability. This improved system can be used effectively in the lab scale biofiltration research. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids
Authors: Ichikawa Akio , Ono Hiroshi , Mikata Yuji
Published: July 2012

The crystal structures of salt 8, which was prepared from (R)‐2‐methoxy‐2‐(2‐naphthyl)propanoic acid ((R)‐MβNP acid, (R)‐2) and (R)‐1‐phenylethylamine ((R)‐PEA, (R)‐6), and salt 9, which was prepared from (R)‐2‐methoxy‐2‐(1‐naphthyl)propanoic acid ((R)‐MαNP acid, (R)‐1) and (R)‐1‐(p‐tolyl)ethylamine ((R)‐TEA, (R)‐7), were determined by X‐ray crystallography. The MβNP and MαNP anions formed ion‐pairs with the PEA and TEA cations, respectively, through a methoxy‐group‐assisted salt bridge and aromatic CH⋅⋅⋅π interactions. The networks of salt bridges formed 21 columns in both salts. Finally, (S)‐(2E,6E)‐(1‐2H1)farnesol ((S)‐13) was prepared from the reaction of (2E,6E)‐farnesal (11) with deuterated (R)‐BINAL‐H (i.e., (R)‐BINAL‐D). The enantiomeric excess of compound (S)‐13 was determined by NMR analysis of (S)‐MαNP ester 14. The solution‐state structures of MαNP esters that were prepared from primary alcohols were also elucidated.
Helical Folding of Conjugated Oligo(phenyleneethynylene): Chain‐Length Dependence, Solvent Effects, and Intermolecular Assembly
Authors: Zhu Ningbo , Yan Qifan , Luo Zhouyang , Zhai You , Zhao Dahui
Published: July 2012

As a representative folding system that features a conjugated backbone, a series of monodispersed (o‐phenyleneethynylene)‐alt‐(p‐phenyleneethynylene) (PE) oligomers of varied chain length and different side chains were studied. Molecules with the same backbone but different side‐chain structures were shown to exhibit similar helical conformations in respectively suitable solvents. Specifically, oligomers with dodecyloxy side chains folded into the helical structure in apolar aliphatic solvents, whereas an analogous oligomer with tri(ethylene glycol) (Tg) side chains adopted the same conformation in polar solvents. The fact that the oligomers with the same backbone manifested a similar folded conformation independent of side chains and the nature of the solvent confirmed the concept that the driving force for folding was the intramolecular aromatic stacking and solvophobic interactions. Although all were capable of inducing folding, different solvents were shown to bestow slightly varied folding stability. The chain‐length dependence study revealed a nonlinear correlation between the folding stability with backbone chain length. A critical size of approximately 10 PE units was identified for the system, beyond which folding occurred. This observation corroborated the helical nature of the folded structure. Remarkably, based on the absorption and emission spectra, the effective conjugation length of the system extended more effectively under the folded state than under random conformations. Moreover, as evidenced by the optical spectra and dynamic light‐scattering studies, intermolecular association took place among the helical oligomers with Tg side chains in aqueous solution. The demonstrated ability of such a conjugated foldamer in self‐assembling into hierarchical supramolecular structures promises application potential for the system.
Contrast-enhanced intraoperative ultrasonography using perfluorobutane microbubbles for the enumeration of colorectal liver metastases
Authors: Takahashi M , Hasegawa K , Arita J , Hata S , Aoki T , Sakamoto Y , Sugawara Y , Kokudo N
Published: July 2012

Background

Intraoperative ultrasonography (IOUS) is considered the standard for the identification of liver metastases. Use of lipid-stabilized perfluorobutane microbubbles as an ultrasound contrast agent may improve this. The value of contrast-enhanced IOUS (CE-IOUS) in enumerating colorectal liver metastases was studied here.

Methods

CE-IOUS was performed in consecutive resections for colorectal liver metastases in 2007–2010. All patients underwent preoperative computed tomography. Magnetic resonance imaging was not carried out routinely. Conventional intraoperative examination including IOUS, and CE-IOUS with peripherally injected contrast were performed. The histopathological findings and 6-month follow-up images were used as the reference standard.

Results

The study group of 102 patients had a total of 315 lesions identified on preoperative imaging (2·4 lesions per operation; 129 operations). Conventional intraoperative examination including IOUS identified 350 lesions (2·7 per operation). CE-IOUS identified 370 lesions (2·9 per operation). The sensitivity, specificity and accuracy of CE-IOUS were 97·1, 59·1 and 93·2 per cent respectively. The CE-IOUS findings altered the surgical plan in 19 operations (14·7 per cent).

Conclusion

CE-IOUS provided additional information to that obtained using contemporary preoperative imaging and conventional intraoperative examinations.
Erythropoietin in the prevention of experimental burn progression
Authors: Tobalem M , Harder Y , Schuster T , Rezaeian F , Wettstein R
Published: July 2012

Background

Damage control is essential in first aid of burn lesions. The aim of the present study was to investigate whether systemic erythropoietin (EPO) administration could prevent secondary burn progression in an experimental model.

Methods

The burn comb model creates four rectangular burn surfaces intercalated by three unburned zones prone to progression. Twenty-one Wistar rats were randomized to a control group or to receive intraperitoneal EPO (500 units per kg) once a day for 5 days starting 45 min (EPO45min) or 6 h (EPO6h) after burn injury. Histological analyses assessing burn depth, inflammation and neoangiogenesis, planimetric evaluation of burn progression, and laser Doppler flowmetry to assess perfusion were performed after 1, 4 and 7 days. Final scarring time and contracture rate were assessed once a week.

Results

Burn progression was decreased significantly with EPO45min but not EPO6h; progression of burn depth stopped in the intermediate dermis (mean(s.e.m.) burn depth score 3·3(0·6) for EPO45min versus 4·7(0·3) and 5·0(0·0) for EPO6h and control respectively on day 7; P = 0·026) and the surface extension was significantly reduced (45(8), 65(4) and 78(4) respectively on day 7; P = 0·017). This was paralleled by faster re-establishment of perfusion with EPO45min (114(5) per cent on day 4 versus 85(6) and 91(3) per cent for EPO6h and control respectively; P = 0·096). The reduction in progression resulted in a decreased healing time (7·3(0·7) weeks for EPO45min versus 11·5(1·0) and 10·8(0·5) weeks for EPO6h and control; P = 0·020) and contracture rate (P = 0·024).

Conclusion

Early EPO prevented burn progression, mainly by improved vascular perfusion.
Soluble endothelial protein C receptor (sEPCR) is likely a biomarker of cancer‐associated hypercoagulability in human hematologic malignancies
Authors: Ducros Elodie , Mirshahi Shah Soltan , Faussat Anne‐Marie , Mirshahi Pezhman , Dimicoli Sophie , Tang Ruoping , Pardo Julia , Ibrahim Jdid , Marie Jean‐Pierre , Therwath Amu , Soria Jeannette , Mirshahi Massoud
Published: July 2012

Elevated plasma level of soluble endothelial protein C receptor (sEPCR) may be an indicator of thrombotic risk. The present study aims to correlate leukemia‐associated hypercoagulability to high level plasma sEPCR and proposes its measurement in routine clinical practice. EPCR expressions in leukemic cell lines were determined by flow cytometry, immunocytochemistry, and reverse transcription polymerase chain reaction (RT‐PCR). EPCR gene sequence of a candidate cell line HL‐60 was also determined. Plasma samples (n = 76) and bone marrow aspirates (n = 72) from 148 patients with hematologic malignancies and 101 healthy volunteers were analyzed by enzyme‐linked immunosorbent assay (ELISA) via a retrospective study for sEPCR and D‐dimer. All leukemic cell lines were found to express EPCR. Also, HL‐60 EPCR gene sequence showed extensive similarities with the endothelial reference gene. All single nucleotide polymorphisms (SNPs) originally described and some new SNPs were revealed in the promoter and intronic regions. Among these patients 67% had plasma sEPCR level higher than the controls (100 ± 28 ng/mL), wherein 16.3% patients had experienced a previous thrombotic event. These patients were divided into: group‐1 (n = 45) with amount of plasmatic sEPCR below 100 ng/mL, group‐2 (n = 45) where the concentration of sEPCR was between 100 and 200, and group‐3 (n = 20) higher than 200 ng/mL. The numbers of thrombotic incidence recorded in each group were four, six, and eight, respectively. These results reveal that EPCR is expressed not only by a wide range of human malignant hematological cells but also the detection of plasma sEPCR levels provides a powerful insight into thrombotic risk assessment in cancer patients, especially when it surpasses 200 ng/mL.
Biosynthesis and Cellular Localization of Functional Polyketides in the Gastropod Mollusc Scaphander lignarius
Authors: Cutignano Adele , Avila Conxita , Rosica Annamaria , Romano Giovanna , Laratta Bruna , Domenech‐Coll Anna , Cimino Guido , Mollo Ernesto , Fontana Angelo
Published: July 2012

Opisthobranchs belong to a subclass of highly evolved and specialised marine gastropods that rely on the use of secondary metabolites for their survival. Here we report the full elucidation of the biosynthesis of aromatic metabolites, lignarenones, in one of these gastropods, the cephalaspidean Scaphander lignarius. Feeding experiments with 2H‐ and 13C‐labelled precursors revealed a mixed acetate/propionate polyketide pathway primed by benzoic acid. Phenylalanine ammonia lyase (PAL), unprecedented in animals, is central to the synthesis of this aromatic precursor by oxidative deamination of L‐phenylalanine to cinnamic acid. Lignarenones are synthesised in the cytoplasm of specialised eukaryotic cells named Blochmann's glands, which are distributed in biosynthetic tissue localised in the vulnerable mantle of the mollusc. This result supports the hypothesis that this lineage of gastropods has acquired the genetic information to produce the chemical substances that they use for their survival.
DFT Calculations Suggest a New Type of Self‐Protection and Self‐Inhibition Mechanism in the Mammalian Heme Enzyme Myeloperoxidase: Nucleophilic Addition of a Functional Water rather than One‐Electron Reduction
Authors: Sicking Wilhelm , Somnitz Holger , Schmuck Carsten
Published: July 2012

The mammalian heme enzyme myeloperoxidase (MPO) catalyzes the reaction of Cl− to the antimicrobial‐effective molecule HOCl. During the catalytic cycle, a reactive intermediate “Compound I” (Cpd I) is generated. Cpd I has the ability to destroy the enzyme. Indeed, in the absence of any substrate, Cpd I decays with a half‐life of 100 ms to an intermediate called Compound II (Cpd II), which is typically the one‐electron reduced Cpd I. However, the nature of Cpd II, its spectroscopic properties, and the source of the additional electron are only poorly understood. On the basis of DFT and time‐dependent (TD)‐DFT quantum chemical calculations at the PBE0/6‐31G* level, we propose an extended mechanism involving a new intermediate, which allows MPO to protect itself from self‐oxidation or self‐destruction during the catalytic cycle. Because of its similarity in electronic structure to Cpd II, we named this intermediate Cpd II′. However, the suggested mechanism and our proposed functional structure of Cpd II′ are based on the hypothesis that the heme is reduced by charge separation caused by reaction with a water molecule, and not, as is normally assumed, by the transfer of an electron. In the course of this investigation, we found a second intermediate, the reduced enzyme, towards which the new mechanism is equally transferable. In analogy to Cpd II′, we named it FeII′. The proposed new intermediates Cpd II′ and FeII′ allow the experimental findings, which have been well documented in the literature for decades but not so far understood, to be explained for the first time. These encompass a) the spontaneous decay of Cpd I, b) the unusual (chlorin‐like) UV/Vis, circular dichroism (CD), and resonance Raman spectra, c) the inability of reduced MPO to bind CO, d) the fact that MPO‐Cpd II reduces SCN− but not Cl−, and e) the experimentally observed auto‐oxidation/auto‐reduction features of the enzyme. Our new mechanism is also transferable to cytochromes, and could well be viable for heme enzymes in general.
Monomer–Dimer Control and Crystal Engineering in TASPs
Authors: Freeman Jon O. , Murphy Michael E. P. , Sherman John C.
Published: July 2012

We have reported a template assembled synthetic protein (cavitein Q4) as an unexpected dimer in the solid state and as a monomer–dimer equilibrium in solution. We have since reported an ability to bias a cavitein’s monomer–dimer equilibrium in solution by sequence design involving histidine metal chelation or disulfide incorporation. However, little remains known about the forces contributing to dimeric cavitein crystal nucleation and lattice stabilization. We, therefore, designed glutamine variants to probe factors involved in dimeric cavitein crystallization. It was found that a key glutamate hydrogen‐bonding interaction between dimers is integral to crystal formation and stabilization. Additionally, we obtained a crystal structure of a cavitein (Q4‐E3H) designed to bias the dimeric structure via histidine metal coordination. The resolved structure indicates a histidine cluster interaction that likely accounts for the biased dimeric form observed in solution.
Chemical and Photochemical Functionality of the First Molecular Bismuth Vanadium Oxide
Authors: Tucher Johannes , Nye Leanne C. , Ivanovic‐Burmazovic Ivana , Notarnicola Antonio , Streb Carsten
Published: July 2012

Anionic metal oxide clusters, so‐called polyoxometalates, can be developed as molecular model compounds to mimic the chemical and photochemical reactivity of solid‐state metal oxides on the molecular level. Inspired by the well‐known visible‐light photocatalyst BiVO4, the first molecular bismuth vanadium oxide has been synthesized to investigate the chemical and photochemical similarities between the solid‐state and molecular compounds. The cluster H3[(Bi(dmso)3)4V13O40]⋅ca. 4 DMSO was obtained from simple precursors in almost quantitative yield. Structural analysis showed that the cluster shell is based on the unusual all‐vanadium ε‐Keggin framework [ε‐V12O40]15−, which is stabilized by coordination of four BiIII centers. The acidic character of the three cluster protons was demonstrated by titration studies. The cluster shows promising photocatalytic properties in visible‐light photooxidation reactions and has high activity (turnover number >1200), high quantum yield (Φ=7.6 %), and good recyclability, which make it a promising first example of a new class of heterometallic polyoxometalates.
Effects of Phosphorus Substituents on Reactions of α‐Alkoxyphosphonium Salts with Nucleophiles
Authors: Goto Akihiro , Otake Kazuki , Kubo Ozora , Sawama Yoshinari , Maegawa Tomohiro , Fujioka Hiromichi
Published: July 2012

The effects of phosphorus substituents on the reactivity of α‐alkoxyphosphonium salts with nucleophiles has been explored. Reactions of α‐alkoxyphosphonium salts, prepared from various acetals and tris(o‐tolyl)phosphine, with a variety of nucleophiles proceeded efficiently. These processes represent the first examples of high‐yielding nucleophilic substitution reactions of α‐alkoxyphosphonium salts. The reactivity of these salts was determined by a balance between steric and electronic factors, respectively, represented by cone angles θ and CO stretching frequencies ν (steric and electronic parameters, respectively). In addition, a novel reaction of α‐alkoxyphosphonium salts derived from Ph3P with Grignard reagents was observed to take place in the presence of O2 to afford alcohols in good yields. A radical mechanism is proposed for this process that has gained support from isotope‐labeling and radical‐inhibition experiments.
Regioselective Hydration of Alkynes by Iron(III) Lewis/Brønsted Catalysis
Authors: Cabrero‐Antonino Jose R. , Leyva‐Pérez Antonio , Corma Avelino
Published: July 2012

The triflimide iron(III) salt [Fe(NTf2)3] promotes the direct hydration of terminal and internal alkynes with very good Markovnikov regioselectivities and high yields. The enhanced carbophilic Lewis acidity of the FeIII cation mediated by the weakly‐coordinating triflimide anion is crucial for the catalytic activity. The iron(III) metal salt can be recycled in the form of the OPPh3/[Fe(NTf2)3] system with similar activity and selectivity. However, spectroscopic and kinetic studies show that [Fe(NTf2)3] hydrolyzes under the reaction conditions and that catalytically less active Brønsted species are formed, which points to a Lewis/Brønsted co‐catalysis. This triflimide‐based catalytic system is regioselective for the hydration of internal aryl‐alkynes and opens the door to a new synthetic route to alkyl ketophenones. As a proof of concept, the synthesis of two antipsychotics Haloperidol and Melperone, with general butyrophenone‐like structure, is shown.
Stereoselective Synthesis of D‐ and L‐Carbocyclic Nucleosides by Enzymatically Catalyzed Kinetic Resolution
Authors: Mahler Miriam , Reichardt Bastian , Hartjen Philip , van Lunzen Jan , Meier Chris
Published: July 2012

An efficient synthesis of (S)‐ or (R)‐3‐(benzyloxy‐methyl)‐cyclopent‐3‐enol was developed by appling an enzyme‐catalyzed kinetic‐resolution approach. This procedure allowed the syntheses of the enantiomeric building blocks (S)‐ and (R)‐cyclopentenol with high optical purity (>98 % ee). In contrast to previous approaches, the key advantage of this procedure is that the resolution is done on the level of enantiomers that only contain one stereogenic center. Owing to this feature, it was possible to chemically convert the enantiomers into each other. By using this route, the starting materials for the syntheses of carbocyclic D‐ and L‐nucleoside analogues were readily accessible. 3′,4′‐Unsaturated D‐ or L‐carbocyclic nucleosides were obtained from the condensation of various nucleobases with (S)‐ or (R)‐cyclopentenol. Functionalization of the double bond in 3′‐deoxy‐3′,4′‐didehydro‐carba‐D‐thymidine led to a variety of new nucleoside analogues. By using the cycloSal approach, their corresponding phosphorylated metabolites were readily accessable. Moreover, a new synthetic route to carbocyclic 2′‐deoxy‐nucleosides was developed, thereby leading to D‐ and L‐carba‐dT. D‐Carba‐dT was tested for antiviral activity against multidrug‐resistance HIV‐1 strain E2‐2 and compared to the known antiviral agent d4T, as well as L‐carba‐dT. Whilst L‐carba‐dT was found to be inactive, its D‐analogue showed remarkably high activity against the resistant virus and significantly better than that of d4T. However, against the wild‐type virus strain NL4/3, d4T was found to be more‐active than D‐carba‐dT.
The Coordination of NiII and CuII Ions to the Polyhistidyl Motif of Hpn Protein: Is It as Strong as We Think?
Authors: Witkowska Danuta , Politano Rossella , Rowinska‐Zyrek Magdalena , Guerrini Remo , Remelli Maurizio , Kozlowski Henryk
Published: July 2012

Hpn, one of Helicobacter pylori′s nickel‐accessory proteins, is an amazingly peculiar protein: Almost half of its sequence consists of polyhistidyl (poly‐His) residues. Herein, we try to understand the origin of this naturally occurring sequence, thereby shedding some light on the bioinorganic chemistry of Hpn′s numerous poly‐His repeats. By using potentiometric, mass spectrometric, and various spectroscopic techniques, we studied the NiII‐ and CuII complexes of the wild‐type Ac‐THHHHYHGG‐NH2 fragment of Hpn and of its six analogues, in which consecutive residues (His or Tyr) were replaced by Ala (Ala‐substitution or Ala‐scan approaches), thereby resulting in Ac‐TAHHHYHGG‐NH2, Ac‐THAHHYHGG‐NH2, Ac‐THHAHYHGG‐NH2, Ac‐THHHAYHGG‐NH2, Ac‐THHHHAHGG‐NH2, and Ac‐THHHHYAGG‐NH2 peptides. We found that the His4 residue is critical for both NiII‐ and CuII‐ion binding and the effectiveness of binding varies even if the substituted amino acid does not take part in the direct binding interactions.
Ca3Sm3[Si9N17] and Ca3Yb3[Si9N17] Nitridosilicates with Interpenetrating Nets that Consist of Star‐Shaped [N[4](SiN3)4] Units and [Si5N16] Supertetrahedra
Authors: Huppertz Hubert , Oeckler Oliver , Lieb Alexandra , Glaum Robert , Johrendt Dirk , Tegel Marcus , Kaindl Reinhard , Schnick Wolfgang
Published: July 2012

New nitridosilicates Ca3Sm3[Si9N17] and Ca3Yb3[Si9N17] were synthesized from the reactions of the pure metals (calcium and samarium/ytterbium) with silicon diimide “Si(NH)2” in a radio‐frequency (rf) furnace at temperatures of up to 1650 °C. These isotypic compounds crystallize in the cubic space group P$\bar 4$3m (no. 215) with lattice parameters a=739.50(3) pm; V=0.4044(1) nm3; Z=1; wR2=0.029 (240 diffraction data, 26 parameters) for Ca3Sm3[Si9N17] and a=730.20(2) pm; V=0.3893(1) nm3; wR2=0.039 (387 diffraction data, 27 parameters) for Ca3Yb3[Si9N17]. The new structure type of Ca3RE3[Si9N17] (RE=Sm, Yb) consists of two independent infinite networks, each of which have an expanded sphalerite (ZnS) topology in which the positions of the Zn and S atoms are replaced by voluminous [N[4](SiN3)4] units and [Si5N16] supertetrahedra, respectively, thereby displaying twofold interpenetration. As well, a structural description of Ca3Yb3[Si9N17], its thermal stability, and magnetic properties, as well as UV/Vis, IR, and Raman spectra, are presented.
A Stand‐Alone Mesoporous Crystal Structure Model from in situ X‐ray Diffraction: Nitrogen Adsorption on 3 D Cagelike Mesoporous Silica SBA‐16
Authors: Miyasaka Keiichi , Hano Hiroko , Kubota Yoshiki , Lin Yangzheng , Ryoo Ryong , Takata Masaki , Kitagawa Susumu , Neimark Alexander V. , Terasaki Osamu
Published: July 2012

We present a modeling scheme to analyze cagelike silica mesoporous crystals based on in situ X‐ray diffraction (XRD) data collected during gas adsorption–desorption (physisorption) processes. Nitrogen physisorption on a silica mesoporous crystal of SBA‐16 was directly monitored by using synchrotron in situ powder XRD measurements conducted at SPring‐8. SBA‐16 is a well‐ordered mesoporous silica in which three‐dimensional interconnected cagelike primary mesopores are located at the body‐centered cubic lattice points. In addition, the surrounding silica matrix contains random microporous and mesoporous intrawall porosities that are significantly influential to the diffusion properties, and thus important to be quantified for this media. The in situ XRD data exhibits seven Bragg reflections throughout the measurements, and the present method allows one to obtain the maximal and stand‐alone information about the pore structure (for example, the mesopore size, the matrix density, the intrawall porosity, and pore surface roughness) together with the nitrogen film evolution in the primary mesopores and the intrawall pore‐filling in the silica matrix. We furthermore observe a macroscopic amount of nitrogen adsorbed assuming the density of the fluid, and confirm that the XRD “isotherm” recalculated from the analysis result is consistent with the conventional nitrogen isotherm on a semi‐quantitative level; however, these results suggest that the intrawall pores would have a greater contribution to the adsorption than considered based on the conventional isotherm analyses. The present method is readily extendable to any ordered mesopores wrapped by the wall matrix containing a certain intrawall porosity.
The Excess Electron in a Boron Nitride Nanotube: Pyramidal NBO Charge Distribution and Remarkable First Hyperpolarizability
Authors: Zhong Rong‐Lin , Xu Hong‐Liang , Sun Shi‐Ling , Qiu Yong‐Qing , Su Zhong‐Min
Published: July 2012

The unusual properties of species with excess electrons have attracted a lot of interest in recent years due to their wide applications in many promising fields. In this work, we find that the excess electron could be effectively bound by the B atoms of boron nitride nanotube (BNNT), which is inverted pyramidally distributed from B‐rich edge to N‐rich edge. Further, Li@B‐BNNT and Li@N‐BNNT are designed by doping the Li atom to the two edges of BNNT, respectively. Because of the interaction between the Li atom and BNNT, the 2s valence electron of Li becomes a loosely bound excess electron. Interestingly, the distribution of the excess electron in Li@N‐BNNT is more diffuse and pyramidal from B‐rich edge to N‐rich edge, which is fascinating compared with Li@B‐BNNT. Correspondingly, the transition energy of Li@N‐BNNT is 0.99 eV, which is obviously smaller than 2.65 eV of Li@B‐BNNT. As a result, the first hyperpolarizability (3.40×104 a.u.) of Li@N‐BNNT is dramatically larger (25 times) than 1.35×103 a.u. of Li@B‐BNNT. Significantly, we find that the pyramidal distribution of the excess electron is the key factor to determine the first hyperpolarizability, which reveals useful information for scientists to develop new electro‐optic applications of BNNTs.
Multiscale Charge Injection and Transport Properties in Self‐Assembled Monolayers of Biphenyl Thiols with Varying Torsion Angles
Authors: Masillamani Appan Merari , Crivillers Núria , Orgiu Emanuele , Rotzler Jürgen , Bossert David , Thippeswamy Ramakrishnappa , Zharnikov Michael , Mayor Marcel , Samorì Paolo
Published: July 2012

This article describes the molecular structure–function relationship for a series of biphenylthiol derivatives with varying torsional degree of freedom in their molecular backbone when self‐assembled on gold electrodes. These biphenylthiol molecules chemisorbed on Au exhibit different tilt angles with respect to the surface normal and different packing densities. The charge transport through the biphenylthiol self‐assembled monolayers (SAMs) showed a characteristic decay trend with the effective monolayer thickness. Based on parallel pathways model the tunneling decay factor β was estimated to be 0.27 Å−1. The hole mobility of poly(3‐hexylthiophene)‐based thin‐film transistors incorporating a biphenylthiol SAM coating the Au source and drain electrodes revealed a dependence on the injection barrier with the highest occupied molecular orbital (HOMO) level of the semiconductor. The possible role of the resistivity of the SAMs on transistor electrodes on the threshold voltage shift is discussed. The control over the chemical structure, electronic properties, and packing order of the SAMs provides a versatile platform to regulate the charge injection in organic electronic devices.
Comparison of Trace Elements in Bottled and Desalinated Household Drinking Water in Kuwait
Authors: Al‐Mudhaf Humood F. , Abu‐Shady Abdel‐Sattar I.
Published: July 2012

The levels of the trace elements aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), antimony (Sb), selenium (Se), strontium (Sr), titanium (Ti), vanadium (V), and zinc (Zn) were determined in 93 brands of non‐carbonated (BW) and carbonated (CBW) bottled water available in Kuwaiti markets and in 321 samples of desalinated household water (HW) collected from 99 sampling locations, which covered 95% of Kuwait's residential areas. The study yielded a large range of results for most of these elements, and the difference between the lowest and highest measured values exceeded three orders of magnitude for some elements in a number of the BW and CBW brands. With a few exceptions, the results for the HW and BW were found to comply with the United States‐Environmental Protection Agency and World Health Organization guideline values. The elements Fe, Pb, Hg, and Ni exceeded these GVs in 8.5, 0.3, 1.2, and 1% of the HW samples, respectively. One brand of BW exceeded the GV for B, while the levels of B, Ba, Be, Fe, and Mn exceeded the GVs in 35, 15, 5, 75, and 25% of the CBW brands, respectively. Correlations were found between the levels of some elements and either the desalination plant that produced the HW or the country of origin of the BW or CBW. The levels of the elements Al, Cu, Fe, and Zn in HW were higher in the summer than in the winter, with 14, 14, 42, and 18% increases, respectively. Nutritional evaluation revealed that significant percentages of the DRIs of Cr, Cu, Fe, and Se can be provided by drinking 2 L of HW, and significant percentages of the DRIs of B, Cr, Cu, and Mo can be provided by drinking 2 L of BW.
Revealing the Bonding Pattern from the Molecular Electron Density Using Single Exponential Decay Detector: An Orbital‐Free Alternative to the Electron Localization Function
Authors: de Silva Piotr , Korchowiec Jacek , Wesolowski Tomasz A.
Published: July 2012

We introduce a new tool (single exponential decay detector: SEDD) to extract information about bonding and localization in atoms, molecules, or molecular assemblies. The practical evaluation of SEDD does not require any explicit information about the orbitals. The only quantity needed is the electron density (calculated or experimental) and its derivatives up to the second order.
A mobicast routing protocol with carry‐and‐forward in vehicular ad hoc networks
Authors: Chen Yuh‐Shyan , Lin Yun‐Wei
Published: July 2012

In vehicular networks, safety and comfort applications are two quite different kinds of applications to avoid the emergency traffic accident and enjoy the non‐emergency entertainment. The comfort application drives the challenges of new non‐emergency entertainments for vehicular ad hoc networks (VANETs). The comfort application usually keeps the delay‐tolerant capability; that is, messages initiated from a specific vehicle at time t can be delivered through VANETs to some vehicles within a given constrained delay time λ. In this paper, we investigate a new mobicast protocol to support comfort applications for a highway scenario in VANETs. All vehicles are located in a geographic zone (denoted as zone of relevance (ZOR)) at time t; the mobicast routing must disseminate the data message initiated from a specific vehicle to all vehicles that have ever appeared in ZOR at time t. This data dissemination must be performed before time t + λ through the carry‐and‐forward technique. In addition, the temporary network fragmentation problem is considered in our protocol design. Also, the low degree of channel utilization is kept to reserve the resource for safety applications. To illustrate the performance achievement, simulation results are examined in terms of message overhead, dissemination success rate, and accumulative packet delivery delay. Copyright © 2012 John Wiley & Sons, Ltd.
Genetic diversity is positively associated with fine‐scale momentary abundance of an invasive ant
Authors: Gruber Monica A. M. , Hoffmann Benjamin D. , Ritchie Peter A. , Lester Philip J.
Published: July 2012

Many introduced species become invasive despite genetic bottlenecks that should, in theory, decrease the chances of invasion success. By contrast, population genetic bottlenecks have been hypothesized to increase the invasion success of unicolonial ants by increasing the genetic similarity between descendent populations, thus promoting co‐operation. We investigated these alternate hypotheses in the unicolonial yellow crazy ant, Anoplolepis gracilipes, which has invaded Arnhem Land in Australia's Northern Territory. We used momentary abundance as a surrogate measure of invasion success, and investigated the relationship between A. gracilipes genetic diversity and its abundance, and the effect of its abundance on species diversity and community structure. We also investigated whether selected habitat characteristics contributed to differences in A. gracilipes abundance, for which we found no evidence. Our results revealed a significant positive association between A. gracilipes genetic diversity and abundance. Invaded communities were less diverse and differed in structure from uninvaded communities, and these effects were stronger as A. gracilipes abundance increased. These results contradict the hypothesis that genetic bottlenecks may promote unicoloniality. However, our A. gracilipes study population has diverged since its introduction, which may have obscured evidence of the bottleneck that would likely have occurred on arrival. The relative importance of genetic diversity to invasion success may be context dependent, and the role of genetic diversity may be more obvious in the absence of highly favorable novel ecological conditions.
Feedback control of electromagnetic actuator with three degrees of freedom using optical image sensors
Authors: Maeda Shuhei , Hirata Katsuhiro , Tong Mingyu
Published: July 2012

Recently, multidimensional actuators have been attracting considerable interest as a solution for increases in size and weight. In this paper, we propose a position feedback control method using optical image sensors for an actuator with three degrees of freedom. The validity of this control method is verified on the basis of the measurement results. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 47–54, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21290