bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemische Bildgebung von räumlichen Heterogenitäten in katalytischen Festkörpern auf unterschiedlichen Längen‐ und Zeitskalen
Authors: Weckhuysen Bert M.
Published: June 2009

Katalytische Festkörper im Rampenlicht: Die gezielte Entwicklung von neuen oder verbesserten heterogenen Katalysatoren erfordert genaue Einblicke in ihre Struktur und Funktionsweise. Hierfür stehen Techniken der chemischen Bildgebung zur Verfügung, die räumlich und zeitlich aufgelöste Informationen über katalytische Festkörper auf unterschiedlichen Längenskalen liefern – d. h. auf der Stufe der Reaktoren, der Katalysatorkörper, der Katalysatorkörner und der Nanopartikel.

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Die Kenntnis räumlich‐zeitlicher Gradienten in heterogenen Katalysatoren ist von allergrößter Bedeutung für den gezielten Entwurf von neuen und nachhaltigeren katalytischen Prozessen. Heterogenitäten, die zu raum‐ und zeitabhängigen Phänomenen führen, kommen auf unterschiedlichen Längenskalen vor, beginnend auf der Stufe der Katalysereaktoren (mm bis m), über die Katalysatorkörper (µm bis mm) und Katalysatorkörner (nm bis µm) bis hin zu den aktiven Zentren und Nanopartikeln (Å bis nm). Dieser Aufsatz fasst die jüngsten Fortschritte bei der Entwicklung von raum‐ und zeitauflösenden Spektroskopiemethoden für die Bildgebung räumlicher Heterogenitäten in katalytischen Prozessen auf diesen vier Längenskalen zusammen. Ein Schwerpunkt liegt auf der Anwendung von Kernresonanz‐, optischen und Synchrotronmethoden, die vor allem auf ihre Fähigkeit zur räumlichen Auflösung (1D‐ und 2D‐Bildgebung) und Tiefenprofilierung (3D‐Bildgebung) untersucht werden. Darüber hinaus werden zeitaufgelöste Anwendungen dieser Techniken diskutiert, ebenso wie ihr Potenzial für die Einzelmolekül‐ und Nanopartikeldetektion und ihr Einsatz unter Reaktionsbedingungen. Der Aufsatz endet mit einem Ausblick auf spektroskopische Aktivitätsmarker, markerfreie Spektroskopie, Tomographie auf der Nanoskala und korrelative mikroskopische Ansätze.
Palladium‐Catalyzed Direct Arylation of Cyclic Enamides with Aryl Silanes by sp2 CH Activation
Authors: Zhou Hai , Xu Yun‐He , Chung Wan‐Jun , Loh Teck‐Peng
Published: June 2009

Aus H wird Ar: Eine fluoridunterstützte direkte Kreuzkupplung zwischen cyclischen Enamiden und Trialkoxyarylsilanen über eine palladiumkatalysierte C‐H‐Aktivierung liefert eine große Bandbreite an Enamiden in Ausbeuten bis 95 %.

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Ultradense Polymer Brushes by Adsorption
Authors: de Vos Wiebe M. , Kleijn J. Mieke , de Keizer Arie , Cohen Stuart Martien A.
Published: June 2009

Vollgepackte Stehplatzränge: Dichte Polymerbürsten entstehen durch Anlagerung von Diblockcopolymeren mit einem neutralen und einem Polyelektrolyt‐Block an entgegengesetzt geladene Polyelektrolytbürsten (siehe Bild). Die Dichte der resultierenden neutralen Bürsten wird bestimmt durch die Ladungskompensation und kann 1 nm−2 übersteigen. Die Diblockcopolymere können durch Wechsel der überstehenden Lösung desorbiert werden.

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Titelbild: Polyketide‐Chain Branching by an Enzymatic Michael Addition (Angew. Chem. 27/2009)
Authors: Kusebauch Björn , Busch Benjamin , Scherlach Kirstin , Roth Martin , Hertweck Christian
Published: June 2009

Der Pilz Rhizopus microsporus , der auf dem Titelbild unter dem Mikroskop betrachtet wird, beherbergt das endosymbiotische Bakterium Burkholderia rhizoxinica, den Produzenten des antimitotischen Polyketidmakrolids Rhizoxin (siehe Struktur). In ihrer Zuschrift auf S. 5101 ff. belegen C. Hertweck und Mitarbeiter, dass nur das Enzym Rhizoxin‐Polyketidsynthase in der Lage ist, durch die Michael‐Addition einer Malonyl‐Einheit an ein Acryloyl‐Intermediat eine β‐Verzweigung einzuführen. Der entsprechende Molekülteil ist bildlich unter die Lupe genommen.

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Ultradense Polymer Brushes by Adsorption
Authors: de Vos Wiebe M. , Kleijn J. Mieke , de Keizer Arie , Cohen Stuart Martien A.
Published: June 2009

Standing room only: Dense polymer brushes can be prepared by adsorbing a diblock copolymer comprising a neutral block and a polyelectrolyte block to an oppositely charged polyelectrolyte brush (see picture). The density of the resulting neutral brush is determined by charge compensation, leading to brush densities well over 1 nm−2. The diblock copolymer can be desorbed by changing the solution conditions.

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Adsorption of Cr(VI) ions onto poly(ethylene glycol dimethacrylate‐1‐vinyl‐1,2,4‐triazole)
Authors: Kara Ali
Published: June 2009

Poly(ethylene glycol dimethacrylate‐1‐vinyl‐1,2,4‐triazole) [poly(EGDMA‐VTAZ)] beads (average diameter = 150–200 μm) were prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1‐vinyl‐1,2,4‐triazole (VTAZ). Poly(EGDMA‐VTAZ) beads were characterized by swelling studies and scanning electron microscope (SEM). The adsorption of Cr(VI) from solutions was carried at different contact times, Cr(VI) concentrations, pH, and temperatures. High adsorption rates were achieved in about 240 min. The amount of Cr(VI) adsorbed increased with increasing concentration and decreasing pH and temperature. The intraparticle diffusion rate constants at various temperatures were calculated. Adsorption isotherms of Cr(VI) onto poly(EGDMA‐VTAZ) have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The pseudo first‐order kinetic model was used to describe the kinetic data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. The dimensionless separation factor (RL) showed that the adsorption of metal ions onto poly(EGDMA‐VTAZ) was favorable. It was seen that values of distribution coefficient (KD) decreasing with Cr(VI) concentration in solution at equilibrium (Ce) indicated that the occupation of activate surface sites of adsorbent increased with Cr(VI). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of two different maleic anhydride‐modified adhesion promoters (PP‐g‐MA) on the structure and mechanical properties of nanofilled polyolefins
Authors: Eteläaho P. , Nevalainen K. , Suihkonen R. , Vuorinen J. , Järvelä P.
Published: June 2009

The effects of adhesion promoter properties on the structure and mechanical behavior of nanoclay‐filled polyolefin nanocomposites are presented. Two different maleic anhydride‐modified polypropylenes having varying maleic anhydride content and molecular weight were used. The influence of these parameters on the performance and morphology of the prepared polypropylene and high density polyethylene‐based nanocomposites was examined by mechanical testing, X‐ray diffraction, and electron microscopy. The low molecular weight adhesion promoter seemed to be effective in both matrices in relation to mechanical property enhancements, whereas its high molecular weight counterpart performed well only in polyethylene matrix. X‐ray diffraction results and examination of morphology revealed that the intercalation and the dispersion of the nanoclay were more even in both matrices when the low molecular weight adhesion promoter with a higher maleic anhydride content was used. On the other hand, the use of high molecular weight adhesion promoter led to a less uniform dispersion but also to a greater amount of exfoliated clay particles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Positive temperature coefficient and time‐dependent resistivity of carbon nanotubes (CNTs)/ultrahigh molecular weight polyethylene (UHMWPE) composite
Authors: Gao Jie‐Feng , Yan Ding‐Xiang , Huang Hua‐Dong , Dai Kun , Li Zhong‐Ming
Published: June 2009

The carbon nanotubes/ultrahigh molecular weight polyethlene (CNTs/UHMWPE) conductive composite with a low percolation threshold had been successfully fabricated, and CNTs were only dispersed in the interface of matrix particles. Some factors, including CNTs concentration, processing temperature, and the time of isothermal treatment, which could exert influence on the positive temperature coefficient effect of the composite, were investigated. Similar with negative temperature coefficient effect, the resistivity decreased during isothermal treatment above the melting point of UHMWPE, which could be thought to be a relaxation process originated from movement of molecular chains. This relaxation, also a process of CNTs aggregating to reorganize the conductive network, was testified as a function of time, temperature, filler concentration, and heating rate. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Structural and mechanical behavior of layered zirconium phosphonate as a distributed phase in polycaprolactone
Authors: Furman Benjamin R. , Wellinghoff Stephen T. , Laine Richard M. , Chan Kwai S. , Nicolella Daniel P. , Rawls H. Ralph
Published: June 2009

Mixed‐surface octyl/methoxyundecyl α‐zirconium phosphonates (ZrPs) were investigated as distributed nanoscale fillers, in concentrations up to 50% w/w, for the purpose of increasing the elastic modulus and yield strength of polycaprolactone (PCL) without a meaningful reduction of its ductility. The volumetric nanoparticle loadings were estimated to be over 70% higher than those in nanocomposites with comparable weight fractions of nanoclay. The mechanical properties of the ZrP/PCL nanocomposite were evaluated with tensile, flexural, and dynamic mechanical testing methods. Nanocomposites containing 5% w/w ZrP showed significant increases in both the tensile yield stress and elastic modulus without any loss of ductility versus the unfilled polymer. Layer delamination from the ZrP tactoids was minimal. Kinetic barriers and the strong interlayer attraction between the ZrP surfaces limited intercalative penetration of the ZrP tactoids. ZrP loadings of 20% w/w or more resulted in the agglomeration of tactoids, leading to defect structures with a loss of strength and, at the highest loading, ductility. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effects of soft‐segment molecular weight and organic modifier on properties of organic‐modified MMT‐PU nanocomposites
Authors: Wang Chia‐Hao , Shieh Yeong‐Tarng , Nutt Steven
Published: June 2009

The effects of soft‐segment molecular weight and organic modification of montmorillonite (MMT) on thermal and mechanical properties of segmented polyurethane (PU) elastomers were investigated. The PU/MMT nanocomposites were prepared by in situ polymerization, and the compositions included soft segments with number average molecular weights of 1000, 2000, and 2900, and organic‐modified MMT (including MMT‐30B and MMT‐I30E). The nanocomposites produced were characterized using wide‐angle X‐ray diffraction (WAXD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and mechanical testing. The TEM and XRD results revealed that both MMT‐30B and MMT‐I30E were intercalated, and partially exfoliated by the PU. Mechanical tests showed that the PU1000 series in soft‐segment molecular weight yielded superior tensile properties compared with the PU2000 and PU2900 series. Also, for a given molecular weight of soft segment in PU, the MMT‐30B nanocomposites exhibited greater increases in Young's modulus, tensile strength, and elongation at break than the MMT‐I30E counterpart, and the crystallinity of PU was enhanced by the clays. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A new method to determine monomer concentration in the polymer particles of emulsion polymerization systems by dynamic light scattering
Authors: Abdollahi Mahdi , Hemmati Mahmoud
Published: June 2009

Emulsifier‐free emulsion polymerization of styrene was performed in the presence of small amount of methacrylic and itaconic acids as carboxylic acid monomers and potassium persulfate as an initiator at 70°C to prepare monodisperse polymer particles. Diameter of monomer swollen polymer particles (dpswol) was measured by dynamic light scattering for samples taken from the reaction mixture during the Intervals II and III of the emulsion polymerization. Graphically treatment of dpswol versus conversion data allowed us for the first time to directly determine the critical monomer conversion (xc), from which constant monomer concentration in the polymer particles (CMP) during the Interval II was then calculated. xc and CMP were obtained to be 0.379 and 5.68, respectively. CMP value is in good agreement with that obtained by centrifugation method and those reported in the literature for the similar system. Attempts were also made to evaluate the average number of growing chain per particle (
$\overline n$) during the Interval II of emulsion polymerization of styrene. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Study on macromolecular lanthanide complexes (V): Synthesis, characterization, and fluorescence properties of lanthanide complexes with the copolymers of styrene and acrylic acid
Authors: Liang Xing , Yang Ying , Jia Xue‐Qing , Niu Li‐e , Qi Xin‐Hua
Published: June 2009

In this study, the luminescent macromolecular lanthanide complexes Ln‐PSt/AA (Ln = Eu and Tb; St = styrene; AA = acrylic acid) have been synthesized, and an extensive characterization has been carried out by means of elemental analysis, FTIR, thermal analysis, and fluorescence determination. The results showed that the carboxylic groups on the chain of the polymers acted as bidentate ligands coordinated to lanthanide ions; and the coordination degree of COO−/Ln3+ in the macromolecular complexes was closely dependent on both the pH value of the solution and the molar ratio of St to AA in the polymeric ligands. Thermal analysis manifested that these Ln‐PSt/AA (Ln = Eu and Tb) complexes had high thermal stability and solvent resistance, and these macromolecular complexes were highly crosslinked. The fluorescence determination indicated that Ln‐PSt/AA complexes could emit characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity changed with increasing lanthanide ions content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and properties of waterborne interpenetrating polymer networks composed of polyurethaneurea and graft vinyl ester resin
Authors: Su Teng , Hu Chun Pu
Published: June 2009

Various waterborne interpenetrating polymer networks (IPNs) composed of polyurethaneurea (PUU) and graft vinyl ester resin were prepared from polyester polyol, dimethylolpropionic acid, isophorone diisocyanate, ethylenediamine and a well‐defined graft vinyl ester resin containing butanol side chains (BO‐g‐VER). These anionic IPN aqueous dispersions were stable at the ambient temperature for >1 yr, and also had the excellent stability at low and high temperatures. The experimental results showed that the introduction of BO‐g‐VER network has not only greatly affected the particle morphology, stability and rheological behavior of these aqueous dispersions, but also rendered the films with the augmented surface hydrophobicity as well as the excellent water‐resistance performance and mechanical properties. A synergistic effect was observed at a certain BO‐g‐VER composition (20 wt %) to give significant reinforcement to the PUU, resulting from the compatibility and/or the interpenetration between the PUU network and the BO‐g‐VER network. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A series of 0‐3 composites of lead zirconate titanate and ferroelectric nylon77: Preparation and electrical properties
Authors: Petchsuk A. , Supmak W. , Thanaboonsombut A.
Published: June 2009

A series of 0‐3 composites of lead zirconate titanate (PZT) and nylon77 was prepared with PZT volume fractions between 0.1 and 0.6 using the combined method of solvent casting and hot pressing. Depending upon the volume fraction of PZT, the relative permittivities of the composites were found to be in the range of 200–2000 when measured at the highest practically possible temperature of 200°C. As PZT volume fraction increases, both the relative permittivity and the piezoelectric constant d33 increase. The best combination of electrical properties and flexibility was obtained in 0.5 PZT volume fraction composites. At this composition, the remanent polarization Pr of composites was up to 1000 mC/m2 at the applied electric field of 40 MV/m and it increased with an increase in temperature. The highest piezoelectric strain coefficient d33 was obtained at 17 pC/N in 0.6 PZT volume fraction composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characteristics of a silicon‐containing polymer, manufacture of an electrolyte membrane from the polymer and poly(vinylidene fluoride‐co‐hexafluoropropene), and property testing of the membrane
Authors: Ye Lin , Ju Ling , Wu Chuan , Feng Ting , Mo Wei , Wu Feng , Bai Ying , Feng Zeng‐guo
Published: June 2009

A silicone‐containing polymer was synthesized by addition polymerization between 1,12‐bis(3‐methyl‐3‐oxetanyl)‐2,5,8,11‐tetraoxadodecane and dichloride dimethylsilane catalyzed by tetrabutylammonium bromide and was characterized by Fourier transform infrared spectroscopy, 1H‐NMR, gel permeation chromatography, and differential scanning calorimetry analyses. To manufacture a tough solid electrolyte membrane, various amounts of a poly(vinylidene fluoride‐co‐hexafluoropropene) copolymer was used to reinforce this silicone‐containing polymer. The mechanical properties and compatibility of the resulting membranes were assessed by mechanical testing and scanning electron microscopy observation. The ionic conductivity was assayed from an alternating‐current impedance spectrum. The results reveal that the maximum ionic conductivity reached 7.4 × 10−5 S/cm at 30°C and 2.6 × 10−4 S/cm at 80°C, respectively. Additionally, the linear sweep voltammetry tests showed that this kind of the blended polymer electrolyte was electrochemical stable until 4.3 V. The thermogravimetric analysis measurements also implied its good thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Homopolymerization effects in polymer layered silicate nanocomposites based upon epoxy resin: Implications for exfoliation
Authors: Pustkova Pavla , Hutchinson John M. , Román Frida , Montserrat Salvador
Published: June 2009

Exfoliation of polymer layered silicate nanocomposites based upon epoxy resin has previously been reported to be enhanced by allowing some homopolymerization of the resin to occur, catalyzed by the onium ion of the organically modified clay, before the addition of the cross‐linking agent and the curing of the nanocomposite. In this work we examine the effects of homopolymerization induced by pre‐conditioning the resin/clay mixtures by storing them at various temperatures, from room temperature to 100°C, prior to curing. It is found that pre‐conditioning results in similar increases in both the epoxy equivalent (EE) and the glass transition temperature (Tg) of the resin as a consequence of homopolymerization, with a linear relationship between EE and Tg that depends on the pre‐conditioning temperature. This is attributed to two different homopolymerization reaction mechanisms, activated monomer (AM) and activated chain end (ACE), the former dominating at high temperature and the latter at low temperature. The effects of these homopolymerization reactions on the network and nanostructure of the nanocomposite are discussed, the important aspect emerging being that the ACE mechanism is the one that most significantly enhances the exfoliation process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Wood‐thermoplastic composites from wood flour and high‐density polyethylene
Authors: Xiong Cheng , Qi Rongrong , Wang Yanling
Published: June 2009

High‐density polyethylene/wood flour (HDPE/WF) composites were prepared by a twin‐screw extruder. The effects of WF, silane coupling agents, polymer compatibilizers, and their content on the comprehensive properties of the WF/HDPE composites have been studied in detail, including the mechanical, thermal, and rheological properties and microstructure. The results showed that both silane coupling agents and polymer compatibilizers could improve the interfacial adhesion between WF and HDPE, and further improve the properties of WF/HDPE composites, especially with AX8900 as a compatibilizer giving higher impact strength, and with HDPE‐g‐MAH as a compatibilizer giving the best tensile and flexural properties. The resultant composite has higher strength (tensile strength = 51.03 MPa) and better heat deflection temperature (63.1°C). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Copolymerization of α‐cyanovinyl acetate with acrylonitrile and methacrylonitrile: Synthesis, characterization, and study of their dielectric behavior
Authors: Arous Mourad , Kallel Ali , Kaddami Hamid , Lahcini Mohamed , Belfkira Ahmed , Raihane Mustapha
Published: June 2009

In the frame of a research aiming at developing new dielectric polymers containing CCN substituent with strong dipole moment, the radical copolymerization of cyano (nitrile) monomers and an α‐cyanovinyl acetate (CVA) as the comonomer, initiated by AIBN is described. Methacrylonitrile (MAN) and acrylonitrile (AN) were chosen as the cyano monomers. The homopolymer of CVA was also prepared and the corresponding yield was close to 60%. All these polymers were characterized by 13C NMR, IR, DSC, and TGA. The percentages of incorporation of AN and MAN in the copolymers were 36 and 56%, respectively. These products showed high glass transition temperatures, Tg, ranging between 124 and 142°C. The thermogravimetry analyses showed that these copolymers are stable up to 200°C. Dielectric spectroscopy analysis revealed a weak relaxation β process below Tg. The α relaxation phenomena have also been characterized around the Tg and associated to the cooperative movements of the polar groups (CN). The values of dielectric relaxation increment were calculated at 150°C using the Havriliak–Negami equation and indicated that these polymers exhibit interesting dielectric properties comparatively to similar cyano materials. The α‐activation energies were also calculated. New statistic copolymers based on CVA were characterized. The values of the intensity of α relaxation show the potential application of such materials in the domain of electronics. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Expression of Hepatocyte Growth Factor and Basic Fibroblast Growth Factor as Prognostic Indicators in Gastric Cancer
Authors: Zhang Wei , Chu Yong‐Quan , Ye Zai‐Yuan , Zhao Zhong‐Sheng , Tao Hou‐Quan
Published: June 2009

We have investigated the correlations among hepatocyte growth factor (HGF) mRNA expression, basic fibroblast growth factor (bFGF) mRNA expression, tumor microvessel density (MVD), and clinical pathological features of gastric cancer in Chinese patients. In situ hybridization was used to detect the expression of HGF and bFGF mRNAs, and immunohistochemistry was used to detect CD34 in 105 gastric cancer tissues and in 20 normal control tissues. The rate of HGF mRNA expression in normal gastric tissues (25%) was significantly lower than that (57.1%) in tumor tissues (P < 0.01). The rates of HGF mRNA and bFGF mRNA expression and MVD in T3–T4 stage tissues were higher than those in T1–T2 stage tissues (P < 0.01); the HGF mRNA expression rate was directly correlated with the bFGF mRNA expression rate (P < 0.05), and they were also directly correlated with MVD (P < 0.01). The mean survival time and the 5‐year survival rate of patients who were positive for expression of HGF mRNA and bFGF mRNA and who had a MVD ≥ 39.5/0.72 mm2 were significantly shorter than those who did not express HGF mRNA and bFGF mRNA and who had a MVD <39.5/0.72 mm2. Both HGF and bFGF may participate in angiogenesis in gastric cancer and may be involved in tumor invasion and metastasis. HGF and bFGF mRNA expression can be used as useful parameters to evaluate the prognosis of gastric cancer. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Role of allatostatin‐like factors from the brain of Tenebrio molitor females
Authors: Wasielewski O. , Skonieczna M. , Kodrík D.
Published: June 2009

The effect of brain extract from females of freshly emerged Tenebrio molitor on ovary, oocyte development, total protein content of hemolymph, and ovary was studied in 4‐day‐old adult mealworm females. Injections of extracts of 2‐brain equivalents into intact (unligatured) Tenebrio females did not affect ovarian and oocyte development. Injections of ligated females, however, with 2‐brain equivalents on day 1 and 2 after adult emergence strongly inhibited ovarian growth and oocyte development. At day 4, ligated and injected females did not develop their ovaries and pre‐vitellogenic oocytes were not found. The changes in ovarian development correlated with an increase in the concentration of soluble proteins in the hemolymph as compared with the saline‐injected controls. Additionally, a strong reduction of total protein content in ovarian tissue was observed. Reverse phase HPLC separation of a methanolic brain extract of T. molitor females showed that fraction 5 has a similar retention time to synthetic cockroach allatostatin. Fraction 5 was eluted at 12.88 min, which was closest to the internal standard Dippu‐AST I, which eluted at 12.77 min. An ELISA of fraction 5 from the methanolic brain extract using antibodies against allatostatins Grybi‐AST A1 and Grybi‐AST B1 from cricket Gryllus bimaculatus showed that fraction 5 cross‐reacted with Grybi‐AST A1 antibodies. The cross‐reactivity was similar to the synthetic allatostatin from D. punctata, which was used as a positive control. These observations demonstrate a possible role for allatostatin‐like brain factor(s) in regulating the reproductive cycle of Tenebrio molitor. © 2009 Wiley Periodicals, Inc.
An integrated inventory model with controllable lead time and distribution‐free demand
Authors: Hsu Shu‐Lu , Huang Yar‐Fen
Published: June 2009

The impact of lead time reduction on an integrated periodic review inventory system comprising a single vendor and multiple buyers with a step crashing cost function and service‐level constraints is studied. The probability distribution of demand during the protection period for each buyer is unknown, but the mean and the variance are given. Each production lot of the vendor can be delivered in a number of shipments to all buyers. A minimax distribution‐free procedure with Lagrange multipliers is applied to determining the lead time, the common shipment cycle time, the target levels of replenishments and the number of shipments per production cycle so that the expected total system cost is minimized. Numerical experiments along with sensitivity analysis were performed to illustrate the effects of parameters on the decision and the total system cost. Copyright © 2009 John Wiley & Sons, Ltd.
Green supply chains and the missing link between environmental information and practice
Authors: Solér Cecilia , Bergström Kerstin , Shanahan Helena
Published: June 2009

Within the field of green supply chain management (GSCM), an interest in supply chain cooperation to create sustainable competitive advantage, i.e. the collaborative paradigm, has made researchers turn their attention to information related aspects of the supply chain. This study contributes to an understanding of a suboptimal use of environmental information, which is critical for all collaborative efforts aiming at sustainable competitive advantage. The aim of this article is to describe the use of environmental information at different stages of the Swedish food supply chain. The results from this case study of the Swedish food supply chain indicate that environmental information is perceived and used differently by purchasers in the supply chain depending on where (in the supply chain) they are situated in relation to other chain actors. The main contribution of this study is the suggestion of a stage‐dependent connection between perceived environmental cost and perceived environmentally informed consumer demand, which are barriers to GSCM practice discussed in recent GSCM literature. The missing link between information sharing and (environmental) performance of supply chains is explained as distance to end‐consumer in terms of supply chain stages. Implications for GSCM practice and theory are discussed. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Impulse‐based rigid body interaction in SPH
Authors: Oh Seungtaik , Kim Younghee , Roh Byung‐Seok
Published: June 2009

A new boundary force is proposed to solve rigid body interaction in SPH (Smoothed Particle Hydrodynamics). The new boundary force is impulse‐based rather than potential‐based. The impulse is converted to a boundary force with a fundamental observation that the impulse is a momentum change which is a result of a force acting on an object during a time interval. Our new impulse‐based boundary force gives more stable and accurate results in all kinds of rigid body interactions, especially in rigid—rigid interaction since our boundary force faithfully reflects the dynamic features of rigid body. With our impulse‐based boundary force, SPH fluid solver is capable of full two way interaction of fluid and rigid body and it turns to be a particle‐based rigid body solver if only rigid bodies are simulated without fluid. Copyright © 2009 John Wiley & Sons, Ltd.
Photochemical Regulation of Restriction Endonuclease Activity
Authors: Young Douglas D. , Govan Jeane M. , Lively Mark O. , Deiters Alexander
Published: June 2009

Removal by the light: The photochemical regulation of restriction endonucleases, which are important enzymes in molecular biology, has been investigated. Photolabile protecting groups have been installed on DNA substrates and have been demonstrated to inhibit restriction endonuclease activity until removed by UV light irradiation. Interestingly, these groups do not appear to dramatically affect initial binding of the enzyme to the DNA substrate, but rather prevent recognition of the specific cleavage site.

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New Structural Variants of Homoserine Lactones in Bacteria
Authors: Thiel Verena , Kunze Brigitte , Verma Pankaj , Wagner‐Döbler Irene , Schulz Stefan
Published: June 2009

N‐Acylhomoserine lactones (AHLs) are used by a wide variety of bacteria for cell–cell communication in “quorum‐sensing”. These compounds are derived from L‐homoserine lactone and a fatty acid, which varies in chain‐length, degree of saturation, and the presence or absence of an oxygen atom at C‐3. In this study we describe for the first time the occurrence of acyl chains carrying a methyl branch, and present a GC‐MS‐based method that can be used to distinguish these compounds from unbranched isomers. The bacterium Aeromonas culicicola produces several methyl branched AHLs. In Jannaschia helgolandensis—a marine bacterium of the Roseobacter clade—a doubly unsaturated AHL, (2E,9Z)‐N‐(2,9‐hexadecadienoyl)‐L‐homoserine lactone, occurs. The location and configuration of the double bonds was proven by spectrometric investigation and synthesis. Finally, a method was developed to establish the absolute configuration of 3‐hydroxyalkanoyl‐HSLs by mild cleavage and chiral gas chromatography. The AHLs synthesized during this study were tested in sensor systems specific for certain AHL types. The results show that these compounds display varying responses to the respective sensors; this underlines the importance of determining the whole bouquet of AHLs and its function to fully understand their importance for regulatory functions in bacteria.
Aphrodisiac Pheromones from the Wings of the Small Cabbage White and Large Cabbage White Butterflies, Pieris rapae and Pieris brassicae
Authors: Yildizhan Selma , van Loon Joop , Sramkova Anna , Ayasse Manfred , Arsene Cristian , ten Broeke Cindy , Schulz Stefan
Published: June 2009

Pheromonally yours: The aphrodisiac pheromones of male Cabbage White butterflies were identified. The small butterfly uses the smaller molecule ferrulactone (1) to enhance its mating success, while the large butterfly uses the larger compound brassicalactone (2), which is a new natural product. Both compounds are active in combination with hexahydrofarnesylacetone and phytol.

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The small and large cabbage butterflies, Pieris rapae and P. brassicae, are found worldwide and are of considerable economic importance. The composition of the male scent‐producing organs present on the wings was investigated. More than 120 components were identified, but only a small portion proved to be male specific. Major components were the known beetle pheromone ferrulactone (1) in P. rapae and its previously unknown larger analogue, brassicalactone (2), in P. brassicae. The latter carries an additional isoprene unit and is closely related to 1. Other components present in larger amounts on male relative to female wings were hexahydrofarnesylacetone (18) and phytol (23). Brassicalactone (2) was fully characterized by synthesis of its various diastereomers by using ring‐closing metathesis. A similar approach to ferrulactone (1) failed, presumably because of its smaller ring size. Instead, this compound was synthesized by using a modified literature procedure. The biological activity of the compounds in the extract was tested by coupled gas chromatographic‐electroantennographic (GC‐EAD) analysis, which showed that both macrolides and the other major components of the wings can be detected by the antennae of the conspecific female butterflies. Other detectable compounds included several alkanes, which are typical constituents of the butterfly cuticula, derivatives of phytol (23) and long‐chain secondary alcohols. Finally, bioassays with males showed that the mixture of 1 (P. rapae) or 2 (P. brassicae) together with 18 and 23 applied to freshly eclosed males increased mating success compared to untreated males. Therefore, the two macrolides 1 and 2 are aphrodisiac pheromone components of male small and large cabbage white butterflies, respectively.
Time‐Resolved Tracking of a Minimum Gene Expression System Reconstituted in Giant Liposomes
Authors: Saito Hirohide , Kato Yusho , Le Berre Maël , Yamada Ayako , Inoue Tan , Yosikawa Kenichi , Baigl Damien
Published: June 2009

Individual expression: We describe a method that allows the observation of real‐time gene expression in a large number of individual giant liposomes encapsulating identical genetic material. We followed the gene expression profiles from DNA and mRNA templates coding for different proteins. Although the average profiles of individual liposomes were similar to those measured in bulk solution, strong variability between individual liposomes was observed at both transcription and translation.

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Expanding RNA Silencing Approaches by U1 Adaptors
Authors: Grünweller Arnold , Hartmann Roland K.
Published: June 2009

Silent partner: In a recent publication, Gunderson and co‐workers described an approach to recruit the abundant U1 snRNP, a splicing subparticle, to the last exon of a pre‐mRNA, in a sequence‐specific manner. This mediates interaction of the U1‐70K protein subunit with poly(A) polymerase, thus blocking polyadenylation and inducing pre‐mRNA degradation. This novel promising strategy expands the repertoire of gene‐silencing concepts.

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Hacking the Genetic Code of Mammalian Cells
Authors: Schwarzer Dirk
Published: June 2009

A genetic shuttle: The highlighted article, which was recently published by Schultz, Geierstanger and co‐workers, describes a straightforward scheme for enlarging the genetic code of mammalian cells. An orthogonal tRNA/aminoacyl‐tRNA synthetase pair specific for a new amino acid can be evolved in E. coli and subsequently transferred into mammalian cells. The feasibility of this approach was demonstrated by adding a photocaged lysine derivative to the genetic repertoire of a human cell line.

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The economics of community college labor markets: A primer
Authors: Kasper Hirschel
Published: June 2009

This chapter provides some basic economic tools to help describe how labor markets work to enable employers and community college students to reach each other to secure productive jobs.
The outlook in business and related fields
Authors: Walker Robert
Published: June 2009

A bachelor's degree is required for many high‐wage jobs, but the community college has an important role to play as an entry and reentry point for a growing number of occupations.
The outlook in the protective service fields
Authors: Talley Gregory , Korsgren Susan
Published: June 2009

The community college is becoming increasingly important in the protective service fields as a screening device and for the skills and knowledge taught.
The outlook for noncredit workforce education
Authors: Van Noy Michelle , Jacobs James
Published: June 2009

The future of noncredit workforce education programs looks bright but organizational, funding, and accountability issues remain.
The outlook for transfer programs and the direction of the community college
Authors: Townsend Barbara K.
Published: June 2009

State‐level interest in meeting workforce needs and facilitating adults' baccalaureate attainment is changing conceptions of the applied associate degree and the mission of the community college.
On the Size of Ions Solvated in Helium Clusters
Authors: Ferreira da Silva Filipe , Waldburger Philipp , Jaksch Stefan , Mauracher Andreas , Denifl Stephan , Echt Olof , Märk Tilmann D. , Scheier Paul
Published: June 2009

Helium nanodroplets are doped with SF6, C4F8, CCl4, C6H5Br, CH3I, and I2. Upon interaction with free electrons a variety of positively and negatively charged cluster ions X±Hen are observed where X±=F±, Cl±, Br±, I+, I2+, or CH3I+. The yield of these ions versus cluster size n drops at characteristic sizes ns that range from ns=10.2±0.6 for F+ to ns=22.2±0.2 for Br−. ns values for halide anions are about 70 % larger than for the corresponding cations. The steps in the ion yield suggest closure of the first solvation shell. We propose a simple classical model to estimate ionic radii from ns. Assuming the helium density in the first solvation shell equals the helium bulk density one finds that radii of halide anions in helium are nearly twice as large as in alkali halide crystals, indicating the formation of an anion bubble due to the repulsive forces that derive from the exchange interaction. In spite of the simplicity of our model, anion radii derived from it agree within approximately 10 % with values derived from the mobility of halide anions in superfluid bulk helium, and with values computed by quantum Monte Carlo methods for X−Hen cluster anions.
Dendrimer Disassembly in the Gas Phase: A Cascade Fragmentation Reaction of Fréchet Dendrons
Authors: Baytekin Bilge , Baytekin H. Tarik , Hahn Uwe , Reckien Werner , Kirchner Barbara , Schalley Christoph A.
Published: June 2009

The mass spectrometric characterization of Fréchet‐type dendrons is reported. In order to provide the charges necessary for electrospray ionization, dendrons bearing an OH group at the focal point can be deprotonated and observed in the negative ion mode. Alternatively, the corresponding bromides can be converted to quaternary ammonium ions that can easily be detected in the positive mode. If the latter ions are subjected to collision‐induced dissociation experiments, a fragmentation cascade begins with the dissociation of the focal amine. The focal benzyl cation quickly decomposes in a fragmentation cascade from the focal point to the periphery until the peripheral benzyl (or naphthylmethyl) cations are formed. Five different mechanisms are discussed in detail, three of which can be excluded based on experimental evidence. The cascade fragmentation is reminiscent of self‐immolative dendrimers.
Structurally Defined Potassium‐Mediated Zincation of Pyridine and 4‐R‐Substituted Pyridines (R=Et, iPr, tBu, Ph, and Me2N) by Using Dialkyl–TMP–Zincate Bases
Authors: Clegg William , Conway Ben , Graham David V. , Hevia Eva , Kennedy Alan R. , Mulvey Robert E. , Russo Luca , Wright Dominic S.
Published: June 2009

Two potassium–dialkyl–TMP–zincate bases [(pmdeta)K(μ‐Et)(μ‐tmp)Zn(Et)] (1) (PMDETA=N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine, TMP=2,2,6,6‐tetramethylpiperidide), and [(pmdeta)K(μ‐nBu)(μ‐tmp)Zn(nBu)] (2), have been synthesized by a simple co‐complexation procedure. Treatment of 1 with a series of substituted 4‐R‐pyridines (R=Me2N, H, Et, iPr, tBu, and Ph) gave 2‐zincated products of the general formula [{2‐Zn(Et)2‐μ‐4‐R‐C5H3N}2⋅2{K(pmdeta)}] (3–8, respectively) in isolated crystalline yields of 53, 16, 7, 23, 67, and 51 %, respectively; the treatment of 2 with 4‐tBu‐pyridine gave [{2‐Zn(nBu)2‐μ‐4‐tBu‐C5H3N}2⋅2{K(pmdeta)}] (9) in an isolated crystalline yield of 58 %. Single‐crystal X‐ray crystallographic and NMR spectroscopic characterization of 3–9 revealed a novel structural motif consisting of a dianionic dihydroanthracene‐like tricyclic ring system with a central diazadicarbadizinca (ZnCN)2 ring, face‐capped on either side by PMDETA‐wrapped K+ cations. All the new metalated pyridine complexes share this dimeric arrangement. As determined by NMR spectroscopic investigations of the reaction filtrates, those solutions producing 3, 7, 8, and 9 appear to be essentially clean reactions, in contrast to those producing 4, 5, and 6, which also contain laterally zincated coproducts. In all of these metalation reactions, the potassium–zincate base acts as an amido transfer agent with a subsequent ligand‐exchange mechanism (amido replacing alkyl) inhibited by the coordinative saturation, and thus, low Lewis acidity of the 4‐coordinate Zn centers in these dimeric molecules. Studies on analogous trialkyl–zincate reagents in the absence and presence of stoichiometric or substoichiometric amounts of TMP(H) established the importance of ZnN bonds for efficient zincation.
Structural Study and Conformational Behavior of the Two Different Lipopolysaccharide O‐Antigens Produced by the Cystic Fibrosis Pathogen Burkholderia multivorans
Authors: Ieranò Teresa , Silipo Alba , Cescutti Paola , Leone Maria Rosaria , Rizzo Roberto , Lanzetta Rosa , Parrilli Michelangelo , Molinaro Antonio
Published: June 2009

Lipopolysaccharides (LPSs) are virulence factors expressed by Gram‐negative bacteria; they are among those mainly responsible for bacterial virulence. In this work we define the primary structure and the conformational features of the O‐chain from the LPS produced by the highly virulent clinical isolate Burkholderia multivorans strain C1576, an opportunistic human pathogen isolated in a cystic fibrosis center and causative of an outbreak with lethal outcome. We demonstrate that the LPS from this clinical isolate consists of two O‐polysaccharide chains present in different amounts and made up of repeating units, both containing deoxy sugar. Additionally, conformational studies have been performed to establish and compare the spatial arrangements of the two polysaccharides and differences in their shape have been highlighted. The comprehension of the structural and conformational features of the two repeating units may help to explain their biological significance, the molecular shape of the bacterial external surface, and the comprehension at the molecular level of the recognition mechanisms of the antibodies.
Arene Control over Thiolate to Sulfinate Oxidation in Albumin by Organometallic Ruthenium Anticancer Complexes
Authors: Hu Wenbing , Luo Qun , Ma Xiaoyan , Wu Kui , Liu Jianan , Chen Yi , Xiong Shaoxiang , Wang Jianping , Sadler Peter J. , Wang Fuyi
Published: June 2009

Arene control: Anticancer complexes [Ru(arene)Cl(en)]+ (arene=p‐cymene or biphenyl; en=ethylenediamine) bind to surface histidine (His128, His247, His510) and methionine (Met298) residues in human albumin, but only the p‐cymene complex can gain entry to the crevice containing the free cysteine thiolate (Cys34) and induce oxidation to sulfinate.

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Interactions of organometallic ruthenium anticancer complexes [Ru(η6‐arene)Cl(en)][PF6] (arene=p‐cymene (1) or biphenyl (2), en=ethylenediamine) with human serum albumin were investigated by means of mass spectrometry combined with trypsin digestion, specific sidechain modifications and computational modelling. Both complexes were shown to bind to surface histidine (His128, His247, His510) and methionine (Met298) residues in human albumin, but only the p‐cymene complex can gain entry to the crevice containing the free cysteine thiolate (Cys34) and induce oxidation to sulfinate. The two complexes exhibit a similar coordination preference for histidine and methionine residues on the protein surface. His128 binding is favoured both kinetically and thermodynamically. At 310 K, six days of incubation of recombinant human albumin (rHA) with complex 1 (rHA:Ru 50:250 μM) led to about 18 % ruthenation of His128 in the protein. However, the extent of ruthenation of albumin by complex 2 was less than that by 1, due to the steric hindrance from the biphenyl ligand. These results imply that the arene ligand in the organometallic ruthenium anticancer complexes plays a crucial role in interactions with proteins.
Synthesis and Evaluation of New Antagonists of Bacterial Quorum Sensing in Vibrio harveyi
Authors: Peng Hanjing , Cheng Yunfeng , Ni Nanting , Li Minyong , Choudhary Gaurav , Chou Han Ting , Lu Chung‐Dar , Tai Phang C. , Wang Binghe
Published: June 2009

Bacterial quorum sensing has received much attention in recent years because of its relevance to pathological events such as biofilm formation. Based on the structures of two lead inhibitors (IC50: 35–55 μM) against autoinducer‐2‐mediated quorum sensing identified through virtual screening, we synthesized 39 analogues and examined their inhibitory activities. Twelve of these new analogues showed equal or better inhibitory activities than the lead inhibitors. The best compound showed an IC50 value of ∼6 μM in a whole‐cell assay using Vibrio harveyi as the model organism. The structure–activity relationship is discussed herein.
Corporate social responsibility: management and methods
Authors: Dobers Peter
Published: June 2009

This article gives an overview of recent Corporate Social Responsibility (CSR) handbooks to illustrate that the field is of immediate interest and relevance for scholars and practitioners. It gives a background to CSR and how the field relates to management and methods and introduces the four articles of this special issue. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Against corporate responsibility: critical reflections on thinking, practice, content and consequences
Authors: Fougère Martin , Solitander Nikodemus
Published: June 2009

This article critically reflects on today's dominant articulation of corporate responsibility (CR) in terms of thinking, practice, content and consequences. We examine what has and has not changed since a seminal critique of the notion of business social responsibility put forward by Theodore Levitt 50 years ago. We illustrate our argument with the case of Botnia in Uruguay, which has recently generated much discussion in international media, and other examples that are illuminating on the problematic nature of contemporary CR. We find that little in fact has changed between the 1958 and 2008 versions of CR except for the context of (global) business, especially the threat posed by sustainability questions and the more systematic ideological rejection of regulation. As opposed to these contemporary evolutions, we call for alternative, regulation‐based articulations of CR, which would improve corporate accountability on social and environmental questions. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.