bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectrophotometric study of interaction and solubilization of procaine hydrochloride in micellar systems
Authors: Hosseinzadeh Reza , Gheshlagi Mohammad , Tahmasebi Rahele , Hojjati Farnaz
Published: December 2008

The interaction of Procaine hydrochloride (PC) with cationic, anionic and non-ionic surfactants; cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and triton X-100, were investigated. The effect of ionic and non-ionic micelles on solubilization of Procaine in aqueous micellar solution of SDS, CTAB and triton X-100 were studied at pH 6.8 and 29°C using absorption spectrophotometry. By using pseudo-phase model, the partition coefficient between the bulk water and micelles, Kx, was calculated. The results showed that the micelles of CTAB enhanced the solubility of Procaine higher than SDS micelles (Kx = 96 and 166 for SDS and CTAB micelles, respectively) but triton X-100 did not enhanced the solubility of drug because of weak interaction with Procaine. From the resulting binding constant for Procaine-ionic surfactants interactions (Kb = 175 and 128 for SDS and CTAB surfactants, respectively), it was concluded that both electrostatic and hydrophobic interactions affect the interaction of surfactants with cationic procaine. Electrostatic interactions have a great role in the binding and consequently distribution of Procaine in micelle/water phases. These interactions for anionic surfactant (SDS) are higher than for cationic surfactant (CTAB). Gibbs free energy of binding and distribution of procaine between the bulk water and studied surfactant micelles were calculated.
Study by grazing incident diffraction and surface spectroscopy of amalgams from ancient mirrors
Authors: Herrera L. , Duran A. , Franquelo M. , González-Elipe A. , Espinós J. , Rubio-Zuazo J. , Castro G. , Justo A. , Perez-Rodriguez J.
Published: December 2008

Characterization of four amalgam surfaces, with different alteration degrees from Andalusia historical mirrors, has been carried out by grazing-incidence X-ray diffraction (GIXRD), and other spectroscopic techniques (SEM/EDX, XPS, and REELS). The combination of all these techniques allows determining the corrosion state of the amalgams. The results show that the amalgams are composed in all cases of a binary alloy of tin and mercury. As mercury has high vapour pressure at RT, it slowly segregates and eventually evaporates, it leaves finely divided particles of tin that easily can be oxidize, forming tin monoxide (SnO) and tin dioxide (SnO2). In one of the samples, most of the amalgam remains unoxidized, since Hg0.1Sn0.9 and metallic Sn phases are the major components; in two other samples, Hg0.1Sn0.9 and Sn phases are not detected while SnO2 and SnO phases appear. Finally, in the last studied sample, only SnO2 phase is detected. The surface analyses of these samples by XPS show that, for most of them an unique chemical species (Sn4+) is found.
Adsorption of lanthanides(III) from aqueous solutions by fullerene black modified with di(2-ethylhexyl)phosphoric acid
Authors: Turanov A. , Karandashevb V.
Published: December 2008

Fullerene black (FB) - a product of electric arc graphite vaporization after extraction of fullerenes - was modified with the di(2-ethylhexyl)phosphoric acid (D2EHPA). The distribution of D2EHPA between FB and aqueous HNO3 solutions has been studied. The effect of HNO3 concentration in the aqueous phase and that of D2EHPA concentration in the sorbent phase on the adsorption of microquantities of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates from HNO3 solutions by D2EHPA-modified FB are considered. The stoichiometry of the sorbed complexes has been determined by the slope analysis method. The efficiency of lanthanides’ adsorption increases with an increase in the element atomic number. A considerable synergistic effect has been observed upon the addition of the neutral bidentate tetraphenylmethylenediphosphine dioxide ligand to D2EHPA in the sorbent phase.
Removal of lead(II) from aqueous solution with amino-functionalized nanoscale zero-valent iron
Authors: Liu Qingyang , Bei Yiling , Zhou Feng
Published: December 2008

An effective adsorbent for removal of Pb(II) in aqueous solution was synthesized by reaction of nanoscale zero-valent iron (NZVI) and 3-aminopropyltriethoxysilane (APS). The material was characterized using transmission electron microscopy (TEM), infrared spectroscopy (IR) and a thermogravimetric analyzer (TGA). The amino-coated NZVI rapidly removed Pb(II) from aqueous solution and was easily separated by an external magnetic field. The Freundlich equation was used for investigating the adsorption process of APS-NZVI. Compared to untreated NZVI, the APS-coated NZVI exhibited stronger adsorption affinity and better adsorption performance. Therefore, APS-NZVI may be a suitable material for heavy metal remediation and has potential industrial applications.
Preparation of nanostructured porous SiO2-Al2O3 oxycarbonitride materials obtained by a new chemical precursor method
Authors: Ivanova Yordanka , Gerganova Tsvetelina , Fernandes M. , Salvado Isabel
Published: December 2008

Nanostructured hybrid materials containing Al2O3 were synthesized via a sol-gel method through hydrolysis and co-condensation reactions using trimethylsilyl isocyanate (TMSI) as a new silica source in the presence of tetramethoxysilane (TMOS) and three different quantities (10, 20 and 30 wt.%) of aluminum sec-butoxide (Al(OBusec)3 as a modifying agent. The xerogel nanostructured materials are pyrolyzed in nitrogen atmosphere in the temperature range from 400°C to 1100°C. The transformation of the xerogel hybrid networks into Al-Si oxycarbonitride materials has been investigated by XRD, FTIR, SEM, AFM, and 29Si MAS-NMR. To the best of our knowledge, the work reported here is the first synthesis of porous di-urethanesils modified with aluminum and one of the few examples of alumosilica oxycarbonitride materials
Bi(NO3)3 · 5H2O mediated synthesis of 4,4′-diaminotriarylmethane leuco malachite compounds under solvent-free conditions
Authors: Bardajee Ghasem , Jafarpour Farnaz
Published: December 2008

In this report, we described the synthesis and characterization of a variety of diaminotriarylmethane derivatives with dimethylamino functional groups. These compounds were synthesized by the tandem regio-selective electrophilic aromatic substitution reaction of N,N-dimethylaniline with aryl aldehydes to form the corresponding diaminotriarylmethane compounds. In our strategy, Bi(NO3)3 was used as a catalyst under solvent free conditions to afford the desired products in good to excellent yields.
Structural characterization of Th-doped TiO2 photocatalyst and its extension of response to solar light for photocatalytic oxidation of oryzalin pesticide: a comparative study
Authors: Gomathi Devi L. , Narasimha Murthy B.
Published: December 2008

The degradation efficiency of Th-doped TiO2 / TiO2 photocatalysts were investigated under UV and solar light illumination. The model compound chosen for the study was Oryzalin (OZ). Doping of inner transition metal ion Th was intended to modify the electronic properties of TiO2. The Th-doped TiO2 were synthesized by incorporating 0.02, 0.04, 0.06, and 0.1 atom percentage of Th into the TiO2 lattice by solid-state reaction. The stochiometry of the prepared samples is Ti1−xThxO2, where ‘x’ is the percentage of Th. The samples were characterized by UV-Visible absorption, UV-Visible -Diffused reflectance spectra, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and X-ray Diffraction (XRD). The pore size and surface area of these samples were studied by Brunauer, Emmett and Teller (BET) adsorption method. It was found that metal ion doping at various percentage compositions enables a large shift in the absorption band of the TiO2 towards visible light region. This is due to the formation of various mid band gaps at 2.84 eV, 2.804 eV, 2.66 eV, and 2.55 eV. The extent of degradation of the pesticide was followed by UV-Visible spectroscopy and GC-MS methods. Based on the spectral analysis, the probable degradation reaction mechanism for OZ is proposed. These results indicate that Th-doped TiO2 with the modified electronic properties is a good catalyst under solar light irradiation. But these particles show marginal variation in rates under UV-illumination. All the photodegradation reactions follow the first order kinetics.
INVESTIGATION OF TRAFFIC‐INDUCED VIBRATION IN VILNIUS ARCH‐CATHEDRAL BELFRY
Authors: Kliukas Romualdas , Jaras Arūnas , Kačianauskas Rimantas
Published: December 2008

The influence of city traffic‐induced vibration on Vilnius Arch‐Cathedral Belfry is investigated. Two sources of dynamic excitation are studied. Conventional city traffic is considered to be a natural source of excitation while excitation imposed artificially by moving a heavily loaded truck is considered to be the source of increased risk excitation. The influence of induced vibrations is recorded by accelerometers located in various positions of the Belfry's structures and shown by accelerograms. Dynamic effects are evaluated by considering acceleration magnitudes and response spectra. A comparative analysis of both effects is presented and conclusions and recommendations are provided.
RESEARCH ON THE COMPATIBILITY OF THE CALCULATION METHODS OF ROLLING‐STOCK BRAKES
Authors: Bureika Gintautas , Mikaliūnas Šarūnas
Published: December 2008

One of the main tasks approached by the European Union is the liberalisation of railway transport service market. The foremost problem solved in this paper is the interoperability of various railway systems in the countries of the European Union. Thus, the immediate goal is to solve the problem of the interoperability of different railway systems used in the European Union. A distinction between railway track gauges (from 1435 to 1668 mm), particular couples of wagons, various clearances of rolling stock, different systems of infrastructure etc. are the main impediments. One of the problems in the nearest future will be the evaluation of the brakes of different wagons produced in Western Europe and the former Soviet Union. Freight trains in Lithuania consist of these two types of wagons, and therefore some problems of correcting the results of calculating braking distances and brake force may arise. The main object of this research is to investigate the methods evaluating the brakes of rolling‐stock and to assess the possibilities of integrating and harmonizing these different methods. The reliability of the methods evaluating the brakes of rolling‐stock is one of the most important components enabling the interoperability of railway transport in the EU network. The brakes of Russian wagons are calculated by MPS Rules for Traction Calculations, approved by the Russian Ministry of Transport (till 2004 ‐ Ministry of Communication Ways of Russia)). On the other hand, the brakes of the wagons produced in Western Europe should be calculated applying TSI (Technical Specifications for Interoperability) methodology. The main parameter following TSI (Technical Specifications for Interoperability) methodology is braked mass and following MPS (Railway Transport Ministry of Russia) method ‐ a pressing force of the brake shoes. The questions of determining the braked mass of wagons and correcting mean braking distance are presented. The compatibility of two different evaluating methods is discussed. Finally, the basic conclusions are given.
LOGISTICS IN ESTONIAN BUSINESS COMPANIES
Authors: Kiisler Ain
Published: December 2008

The article describes logistics survey in Estonia carried out in 2007 as a part of the LogOnBaltic project. The level of logistics in Estonian manufacturing, trading and logistics companies is explored through logistics costs, performance indicators, outsourcing, ICT use and logistics self‐estimation of the companies responded. Responses from 186 Estonian companies were gathered through a web‐based survey (38% of manufacturing, 38% of trading and 24% of logistics sector). Logistics costs as the percentage of turnover make in average 13.8% in manufacturing and 13.3% in trading. Transportation and inventory carrying cost form around 70% of overall logistics costs. Considering the logistics indicators surveyed, Estonian companies show up with relatively low perfect order fulfillment rates, short customer order fulfillment cycles and effective management of cash flows. The most widely outsourced logistics function is international transportation followed by domestic transportation, freight forwarding and reverse logistics. By 2010, the outsourcing of IT systems in logistics followed by inventory management, warehousing and product customization is expected to increase more substantially. The awareness of logistics importance is still low among Estonian companies. Only 27–44% of those agree that logistics has a considerable impact on profitability, competitive advantage, top management or customer service level.
The FMR1 gene and fragile X‐associated tremor/ataxia syndrome
Authors: Brouwer J.R. , Willemsen R. , Oostra B.A.
Published: December 2008

The CGG‐repeat present in the 5′UTR of the FMR1 gene is unstable upon transmission to the next generation. The repeat is up to 55 CGGs long in the normal population. In fragile X patients, a repeat length exceeding 200 CGGs (full mutation: FM) generally leads to methylation of the repeat and the promoter region, which is accompanied by silencing of the FMR1 gene. The gene product FMRP is involved in regulation of transport and translation of certain mRNA in the dendrite, thereby affecting synaptic plasticity. This is central to learning and memory processes. The absence of FMRP seen in FM is the cause of the mental retardation seen in fragile X patients. The premutation (PM) is defined as 55–200 CGGs. Female PM carriers are at risk of developing primary ovarian insufficiency. Recently it was discovered that elderly PM carriers might develop a progressive neurodegenerative disorder called fragile X‐associated tremor/ataxia syndrome. Although arising from the mutations in the same gene, distinct mechanisms lead to fragile X syndrome (absence of FMRP) and FXTAS (toxic RNA gain of function). The pathogenic mechanisms thought to underlie these disorders are discussed, with a specific emphasis on FXTAS. This review gives insight on the implications of all possible repeat length categories seen in fragile X families. © 2008 Wiley‐Liss, Inc.
Association of reduced folate carrier gene polymorphism and maternal folic acid use with neural tube defects
Authors: Pei Lijun , Liu Jianmeng , Zhang Yewu , Zhu Huiping , Ren Aiguo
Published: December 2008

This study was designed to investigate whether the risk for neural tube defects (NTDs) was associated with reduced folate carrier gene (RFC1 A80G) polymorphism and/or with the interaction between the RFC1 gene and maternal periconceptional use of folic acid. One hundred four nuclear families with NTDs and 100 non‐malformed control families were sampled to investigate the potential interaction between maternal or the offspring's RFC1 (A80G) genotypes and the maternal periconceptional use of folic acid through a population‐based case–control study. RFC1 (A80G) genotypes were detected using PCR‐restricted fragment length polymorphism (PCR‐RFLP). Mother who had the GG genotype and did not take folic acid had an elevated risk for NTDs (OR = 5.43, 95% CI = 1.68–18.28) as compared to the mother who had AA or GA genotype and took maternal periconceptional folic acid. The interactive coefficient was 1.12 between maternal GG genotype and the periconceptional folic acid non‐use. The risk for having an infant with NTDs was 8.80 (95% CI = 2.83–28.69) for offspring with the GG genotype, as compared to the offspring with AA or GA genotype among the mothers who did not take folic acid supplements. The interactive coefficient was 1.45 for offspring with the GG genotype and without maternal periconceptional supplementation of folic acid. Our findings suggest that there is a potential gene–environment interaction on the risk of NTDs between maternal or offspring RFC1 GG genotype and maternal periconceptional intake of folic acid. The RFC1 is likely to be an important candidate gene in folate transportation and RFC1 GG genotype (A80G) may be associated with an increased risk for NTDs in this Chinese population. © 2008 Wiley‐Liss, Inc.
Fast responsive and strong swelling hydrogels based on N‐isopropylacrylamide with sodium acrylate
Authors: Huang He , Zhang Dan , Mao Zhiping , Yu Weidong , Yan Haojing
Published: December 2008

Poly(N‐isopropylacrylamide‐co‐sodium acrylate) gels with N,N‐methylene bisacrylamde (BIS) as crosslinker were prepared by free radical polymerization method at the temperature of 35°C, which was just around the lower critical solution temperature (LSCT) of the hydrogels. The gels synthesized at 35°C demonstrated strong swellability and fast responseability when compared with the gels synthesized at the temperature of 0 and 18°C (below the LCST) and 50 and 80°C (above the LSCT). The response rate and swelling behavior of poly(N‐isopropylacrylamide‐co‐sodium acrylate) gels was investigated and characterized by the temperature‐dependent swelling ratio and swelling and deswelling kinetics. The swelling behavior of the gels indicated that the synthesis temperature was the main factor when the swellability concerned and also had effect on the responseability of the resulting hydrogels. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effect of the mixtures of photoinitiators in polymerization efficiencies
Authors: Neumann Miguel G. , Schmitt Carla C. , Horn Marco A.
Published: December 2008

The photoinitiated polymerization of methyl methacrylate using the mixtures of camphorquinone (CQ) and acylphosphine oxides (monoacylphosphine oxide, MAPO, or bisacylphosphine oxide, BAPO) was studied to determine the possible synergistic effects. The addition of the acylphosphines to CQ resulted in an increase of the polymerization rate compared with CQ alone. On the other hand, a significant decrease of the polymerization quantum yield is observed for the mixtures compared with the pure acylphosphines. Therefore, the increase in the polymerization efficiency of the two mixtures studied, MAPO/CQ and BAPO/CQ (compared with CQ) can be traced to the larger light absorption range, rather than to the onset of new mechanisms. The presence of the coinitiator ethyl 4‐dimethylaminobenzoate, EDB, always present in CQ formulations, has no effect at all on the rates of polymerization photoinitiated by the acylphosphine oxides. From the point of view of photopolymerization quantum yields, an antagonistic effect is observed because of the energy transfer of the more efficient initiator (MAPO or BAPO) to the less efficient one (CQ). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fast responsive poly(acrylic acid‐co‐N‐isopropyl acrylamide) hydrogels based on new crosslinker
Authors: Atta Ayman M. , Abdel‐Bary E. M. , Rezk Kamel , Abdel‐Azim A.
Published: December 2008

Novel dual temperature‐ and pH‐sensitive poly(acrylic acid‐co‐N‐isopropylacrylamide), AA/NIPAAm, hydrogels were successfully prepared by chemical crosslinking with crosslinkers. Copolymers of AA/NIPAAm were crosslinked in the presence of different mol % of N,N‐methylene bisacrylamide (MBA) and melamine triacrylamide (MAAm) as crosslinkers by bulk radical polymerization. The resultant xerogels were characterized by extracting the soluble fractions and measuring the equilibrium water content. Lower critical solution transition temperatures (LCST) were measured by DSC. The properties of crosslinked AA/NIPAAm series are evaluated in terms of compositional drift of polymerization, heterogeneous crosslinking, and chemical structure of the relevant components. Soluble fractions of the crosslinked networks were reduced by varying the MAAm and MBA concentrations. The influence of environmental conditions such as temperature and pH on the swelling behavior of these polymeric gels was investigated. The swelling behaviors of the resulting gels show pH sensitivity. The prepared MAAm type AA/NIPAAm hydrogels exhibited a more rapid deswelling rate than MBA type AA/NIPAAm hydrogels in ultra pure water in response to abrupt changes from 20°C to 50°C. The results of this study provide valuable information regarding the development of dual stimuli‐sensitive hydrogels with fast responsiveness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis, characterization, and properties of polymeric flocculant with the function of trapping heavy metal ions
Authors: Hao Xuekui , Chang Qing , Li Xiaohong
Published: December 2008

A novel crosslinked starch‐graft‐polyacrylamide‐co‐sodium xanthate (CSAX) was synthesized by grafting copolymerization reactions of crosslinked corn starch, acrylamide (AM), and sodium xanthate, using epichlorohydrin (EPI) as crosslinking reagent and ceric ammonium nitrate as initiator in aqueous solution. The effects of some factors, such as crosslinker, initiator, AM, NaOH and so forth, on the flocculation were investigated in terms of efficiency of grafting (% GE), grafting percentage (% GP), and viscosity averaged molecular weight (M) of the PAM pendant chains. The results showed that the CSAX was successfully synthesized with the different number and length of grafted PAM pendant chains and with the functions of removing both substance causing turbidity and heavy metal ions from aqueous solution. Under optimum synthesis conditions, CSAX exhibited excellent performances: the rate of turbidity removal (% T) reached 98.4% and the rate of Cu2+ removal (% R) reached 99.2% in water treatment, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of wettability and silicone surface modification on the self‐cleaning functionalization of wool
Authors: Tung Wing Sze , Daoud Walid A.
Published: December 2008

Self‐cleaning wool has been realized by treatment with a colloidal sol of anatase nanocrystals. However, the mechanical properties of wool have been significantly deteriorated following the self‐cleaning functionalization treatment. To minimize the undesirable side‐effects induced by the nanocoating, a silicone surface modification post‐treatment has been introduced. The change in mechanical properties of TiO2‐coated wool after modification with silicone was examined, and the effect of this process on the photocatalytic activity and its stability was assessed by a degradation test of food stains. Moreover, the wettability of wool has been modified using different nonionic wetting agents, in an attempt to shorten the wetting time during dip‐coating and the absorption rate was compared. The effect of wetting agents on the functionalization process and the photocatalytic activity was examined. The synchronized effect of wettability and silicone surface modification on the self‐cleaning functionalization of wool was also studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of organic peroxides on the morphology and properties of EVA/Cloisite 15A nanocomposites
Authors: Mishra S. B. , Luyt A. S.
Published: December 2008

This article describes the effect of the presence of organic peroxides on the morphology and properties of ethylene vinyl acetate copolymer (EVA)/Cloisite 15A nanocomposites. The results show that the presence of dicumyl peroxide (DCP) or dibenzoyl peroxide (DBP) during the preparation of EVA/Cloisite 15A clay nanocomposites gives rise to intercalated, exfoliated, or mixed morphologies, which are not normally observed for samples prepared in the absence of organic peroxides. In the absence of clay, both DCP and DBP initiate de‐acetylation and chain scission of EVA chains, but the influence of DBP is more pronounced. The presence of clay inhibits the initiation of EVA degradation by DCP free radicals, which can be observed in the higher tensile strength values for DCP treated samples, as well as in the de‐acetylation step in the TGA curves. DBP has a more significant influence on the polymer degradation, and this gives rise to reduced thermal stability and mechanical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improving blood compatibility of natural rubber by UV‐induced graft polymerization of hydrophilic monomers
Authors: Hoven Voravee P. , Chombanpaew Kamolmart , Iwasaki Yasuhiko , Tasakorn Pianpak
Published: December 2008

Natural rubber (NR) latex films surface‐grafted with hydrophilic monomers, poly(ethylene glycol) methacrylate (PEGMA), N‐vinylpyrrolidone (VPy), and 2‐methacryloyloxyethyl phosphorylcholine (MPC), were prepared by UV‐induced graft polymerization using benzophenone as a photosensitizer. The grafting yield increases of vulcanized NR latex films as a function of time and monomer concentration were of lesser magnitude than those of the unvulcanized NR latex films. This can be explained as a result of the crosslinked network generated during vulcanization acting as a barrier to the permeation of the photosensitizer and the monomer. The appearance of a characteristic carbonyl stretching in the attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR) spectra of NR latex films after the surface grafting of PEGMA and MPC indicates that the modification has proceeded at least to the sampling depth of ATR‐FTIR (∼ 1–2 μm). According to the water contact angle of the modified NR latex films, the surface grafting density became higher as the grafting time and monomer concentration increased. The complete absence of plasma protein adsorption and platelet adhesion on the surface‐modified NR latex films having grafting yield above 1 wt % is a strong indication of improved blood compatibility. Results from tensile tests suggest that graft polymerization does not cause adverse effects on the mechanical properties of vulcanized NR latex films. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Comparison of the thermal degradation of natural, alkali‐treated and silane‐treated hemp fibers under air and an inert atmosphere
Authors: Rachini Ali , Le Troedec Marianne , Peyratout Claire , Smith Agnès
Published: December 2008

To estimate the contribution of all major components to the thermal properties of natural hemp fiber bundles, the thermal decomposition of hemp fibers following several chemical treatments was studied by the differential thermogravimetric analysis (DTA/TGA). Contrary to what was observed with measurements conducted under air, the thermal degradation of all major hemp fiber components (pectins, hemicellulose, cellulose, and lignin principally) could be easily detected and deconvoluted under inert atmosphere. The intensity of the TGA peaks observed at 235°C (characteristics of pectin) and at 265°C (characteristics of hemicellulose) decreased after all fiber chemical treatments. This resulted in an overall increase of the cellulose percentage. Based on the onset temperature of DTA, it was found that the thermal stability decreased in the following order: NaOH‐treated fibers, silane‐treated fibers, solvent extracted fibers (water/ethanol mixture, 20/80 v/v), and untreated hemp fibers. Moreover, the difference of the mass loss (%) between TGA under argon of silane‐treated fibers and untreated fibers showed that some silane molecules were chemically attached to hemp fiber bundles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Crystallization, mechanical, and rheological behavior of polyvinylidene fluoride/carbon nanofiber composites
Authors: Vidhate Shailesh , Shaito Ali , Chung Jaycee , D'Souza Nandika Anne
Published: December 2008

Composites of polyvinylidene fluoride (PVDF)/carbon nanofibers (CNFs) with different nanofiber contents were prepared by melt‐blending using a twin‐screw extruder by directly mixing CNFs with PVDF in the molten state. Fibers were extruded from the blended pellets. CNFs improved the nucleation efficiency of PVDF but the percent crystallinity decreased with increasing CNF concentration. X‐ray diffraction results showed a change in the α phase, but the transition to the β phase did not occur. Dynamic mechanical analysis (DMA) indicated an improvement in storage modulus and reduced damping factor with increasing CNF concentration. A complementary improvement in mechanical properties was determined from tensile test results. Rheological measurements indicated increased storage modulus, loss modulus, and viscosity values with an increased percentage of CNFs in the PVDF. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Combinatorial Mutasynthesis of Scrambled Beauvericins, Cyclooligomer Depsipeptide Cell Migration Inhibitors from Beauveria bassiana
Authors: Xu Yuquan , Wijeratne E. M. Kithsiri , Espinosa‐Artiles Patricia , Gunatilaka A. A. Leslie , Molnár István
Published: December 2008

Fungal cyclooligomer depsipeptides such as beauvericin, bassianolide, and enniatins display antibiotic, antifungal, insecticidal, broad‐spectrum cancer cell antiproliferative, and cell migration inhibitory activities. We have identified a gene encoding a novel enzyme, ketoisovalerate reductase (KIVR), which is the sole provider of D‐hydroxyisovalerate (D‐Hiv), a common precursor for cyclooligomer depsipeptide biosynthesis in Beauveria bassiana. KIVR and related hypothetical oxidoreductases encoded in fungal genomes are similar to ketopantoate reductases but not to D‐hydroxycarboxylate dehydrogenases. We demonstrate that a KIVR knockout B. bassiana strain can be used for the efficient mutasynthesis of unnatural beauvericin congeners. Simultaneous feeding of precursor analogues enabled the combinatorial mutasynthesis of scrambled beauvericins, some assembled entirely from unnatural precursors. The effects of the introduced structural changes on the antiproliferative and cell migration inhibitory activities of these analogues were evaluated.
Structural and Magnetic Insights into the Trinuclear Ferrocenophane and Unexpected Hydrido Inverse Crown Products of Alkali‐Metal‐Mediated Manganation(II) of Ferrocene
Authors: Blair Victoria L. , Carrella Luca M. , Clegg William , Klett Jan , Mulvey Robert E. , Rentschler Eva , Russo Luca
Published: December 2008

With the aim of introducing the diisopropylamide [NiPr2]− ligand to alkali‐metal‐mediated manganation (AMMMn) chemistry, the temperature‐dependent reactions of a 1:1:3 mixture of butylsodium, bis(trimethylsilylmethyl)manganese(II), and diisopropylamine with ferrocene in hexane/toluene have been investigated. Performed at reflux temperature, the reaction affords the surprising, ferrocene‐free, hydrido product [Na2Mn2 (μ‐H)2{N(iPr)2}4]⋅2 toluene (1), the first Mn hydrido inverse crown complex. Repeating the reaction rationally, excluding ferrocene, produces 1 in an isolated crystalline yield of 62 %. At lower temperatures, the same bimetallic amide mixture leads to the manganation of ferrocene to generate the first trimanganese, trinuclear ferrocenophane, [{Fe(C5H4)2}3{Mn3Na2(NiPr2)2 (HNiPr2)2}] (2) in an isolated crystalline yield of 81 %. Both 1 and 2 have been characterised by X‐ray crystallographic studies. The magnetic properties of paramagnetic 1 and 2 have also been examined by variable‐temperature magnetisation measurements on powdered samples. For 1, the room‐temperature value for χT is 3.45 cm3 K mol−1, and on lowering the temperature a strong antiferromagnetic coupling between the two Mn ions is observed. For 2, the room‐temperature value for χT is 4.06 cm3 K mol−1, which is significantly lower than the expected value for three isolated paramagnetic MnII ions.
Functionally Rigid and Degenerate Molecular Shuttles
Authors: Yoon Il , Benítez Diego , Zhao Yan‐Li , Miljanić Ognjen Š. , Kim Soo‐Young , Tkatchouk Ekaterina , Leung Ken C.‐F. , Khan Saeed I. , Goddard William A. , Stoddart J. Fraser
Published: December 2008

The preparation and dynamic behavior of two functionally rigid and degenerate [2]rotaxanes (1⋅4 PF6 and 2⋅4 PF6) in which a π‐electron deficient tetracationic cyclophane, cyclobis(paraquat‐p‐phenylene) (CBPQT4+) ring, shuttles back and forth between two π‐electron‐rich naphthalene (NP) stations by making the passage along an ethynyl‐phenylene‐(PH)‐ethynyl or butadiyne rod, are described. The [2]rotaxanes were synthesized by using the clipping approach to template‐directed synthesis, and were characterized by NMR spectroscopic and mass spectrometric analyses. 1H NMR spectra of both [2]rotaxanes show evidence for the formation of mechanically interlocked structures, resulting in the upfield shifts of the resonances for key protons on the dumbbell‐shaped components. In particular, the signals for the peri protons on the NP units in the dumbbell‐shaped components experienced significant upfield shifts at low temperatures, just as has been observed in the flexible [2]rotaxanes. Interestingly, the resonances for the same protons did not exhibit a significant upfield shift at 298 K, but rather only a modest shift. This phenomenon arises from the much reduced binding of the ethynyl‐NP unit compared to the 1,5‐dioxy‐NP unit. This effect, in turn, increases the shuttling rate when compared to the 1,5‐dioxy‐NP‐based rotaxane systems investigated previously. The kinetic and thermodynamic data of the shuttling behavior of the CBPQT4+ ring between the NP units were obtained by variable‐temperature NMR spectroscopy and using the coalescence method to calculate the free energies of activation (ΔGc≠) of 9.6 and 10.3 kcal mol−1 for 1⋅4 PF6 and 2⋅4 PF6, respectively, probed by using the rotaxane's α‐bipyridinium protons. The solid‐state structure of the free dumbbell‐shaped compound (3) shows the fully rigid ethynyl‐PH‐ethynyl linker with a length (8.1 Å) twice as long as that (3.8 Å) of the butadiyne linker. Full‐atomistic simulations were carried out with the DREIDING force field (FF) to probe the degenerate molecular shuttling processes, and afforded shuttling energy barriers (ΔG≠=10.4 kcal mol−1 for 1⋅4 PF6 and 2⋅4 PF6) that are in good agreement with the experimental values (ΔGc≠=9.6 and 10.3 kcal mol−1 for 1⋅4 PF6 and 2⋅4 PF6, respectively, probed by using their α‐bipyridinium protons).
Tamoxifen modulates apoptosis in multiple modes of action in CreER mice
Authors: Takebayashi Hirohide , Usui Noriyoshi , Ono Katsuhiko , Ikenaka Kazuhiro
Published: December 2008

Tamoxifen‐inducible Cre (CreER) has become a powerful tool for in vivo manipulation of the genome. Here, we investigated opposing effects of tamoxifen on apoptosis during embryogenesis using Olig2–CreER knock‐in mice, namely, tamoxifen‐induced apoptosis through CreER‐mediated toxicity and cytoprotective activity of tamoxifen independent of CreER. First, we examined tamoxifen‐induced apoptosis; in the homozygous mice, we observed region‐specific apoptosis in the ventral neural tube, with no obvious increase in the heterozygotes. Next, we detected a cytoprotective effect on apoptosis in the homozygous dorsal root ganglia (DRG). This apoptosis is a secondary phenotype of Olig2‐null mice, as Olig2/CreER is not expressed in the DRG. The cytoprotective effect is DRG‐specific, because tamoxifen did not rescue apoptosis in the interdigital mesenchyme. These data indicate that tamoxifen has multiple effects on apoptosis during development and caution that careful examination is necessary when interpreting results obtained from tamoxifen‐induced recombination: in Olig2‐CreER mice, heterozygotes are usable for lineage‐tracing experiment without obvious toxicity, while homozygotes show efficient recombination, despite enhanced apoptosis. genesis 46:775–781, 2008. © 2008 Wiley‐Liss, Inc.
The construction of Mendel's laws
Authors: Marks Jonathan
Published: December 2008

While “Mendel's Laws” are generally taught as natural facts, they are actually pedagogical constructions, which originated in a series of lectures at Princeton in 1916. What accounts for their popularity?
Preliminary in vitro evaluation of an adjunctive therapy for extremity wound infection reduction: Rapidly resorbing local antibiotic delivery
Authors: Jackson Stephanie R. , Richelsoph Kelly C. , Courtney Harry S. , Wenke Joseph C. , Branstetter Joanna G. , Bumgardner Joel D. , Haggard Warren O.
Published: December 2008

Despite the continuing advances in treatment of open fractures and musculoskeletal wounds, infection remains a serious complication. Current treatments to prevent infection utilize surgical debridement and irrigation, and high doses of systemic antimicrobial therapy. The aim of this work was to evaluate, in vitro, the potential of a fast‐resorbing calcium sulfate pellet loaded with an antibiotic. The pellet could be used as an adjunctive therapy at the time of debridement and irrigation to reduce bacterial wound contamination. Small pellets containing a binder and calcium sulfate were engineered to resorb rapidly (within 24 h) and deliver high local doses of antibiotic (amikacin, gentamicin, or vancomycin) to the wound site while minimizing systemic effects. Results from dissolution, elution, and biological activity tests against P. aeruginosa and S. aureus were used to compare the performance of antibiotic‐loaded, rapidly resorbing calcium sulfate pellets to antibiotic‐loaded crushed conventional calcium sulfate pellets. Antibiotic‐loaded rapidly resorbing pellets dissolved in vitro in deionized water in 12–16 h and released therapeutic antibiotic levels in phosphate buffered saline that were above the minimal inhibitory concentration for P. aeruginosa and S. aureus, completely inhibiting the growth of these bacteria for the life of the pellet. Crushed conventional calcium sulfate pellets dissolved over 4–6 days, but the eluates only contained sufficient antibiotic to inhibit growth for the first 4 h. These data indicate that fast‐resorbing pellets can release antibiotics rapidly and at therapeutic levels. Adjunctive therapy with fast‐acting pellets is promising and warrants further in vivo studies. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 903–908, 2009
Chromosomal and proteome analysis of a new T24‐based cell line model for aggressive bladder cancer
Authors: Makridakis Manousos , Gagos Sarantis , Petrolekas Andreas , Roubelakis Maria G. , Bitsika Vasiliki , Stravodimos Konstantinos , Pavlakis Kitty , Anagnou Nicholas P. , Coleman Jonathan , Vlahou Antonia
Published: December 2008

Cell line models aid in understanding cancer aggressiveness. The aim of this study was the establishment of a metastatic variant (T24M) of the T24 bladder cancer cell line and its initial characterization at chromosomal and proteomic levels. T24M were spontaneously developed in mice from T24 cells, following cycles of subcutaneous injections and culture in vitro. Transwell migration assays and injections in mice revealed increased migration and tumorigenic properties of T24M compared to the T24 cells. Cytogenetic analysis demonstrated that T24M retained several karyotypic characteristics of the parental cells and also acquired novel chromosomal aberrations related to aggressive bladder cancer. Proteomic analysis of the T24 and T24M cells by 2‐DE and MS led to the generation of their 2‐DE proteomic map and revealed differences in multiple proteins. These include proteases of the lysosomal and proteasome degradation pathways, mitochondrial and cytoskeletal proteins. The 2‐DE findings were confirmed by immunoblotting of cell lysates and immunohistochemistry of bladder cancer tissue sections for cathepsin D and activity assays for proteasome. Collectively, our results suggest that the T24M cells reflect many known chromosomal and proteomic aberrations encountered in aggressive bladder cancers but also provide access to novel findings with potentially clinical applications.
Analysis of cotton (Gossypium hirsutum) root proteomes during a compatible interaction with the black root rot fungus Thielaviopsis basicola
Authors: Coumans Joëlle V. F. , Poljak Anne , Raftery Mark J. , Backhouse David , Pereg‐Gerk Lily
Published: December 2008

A proteomic approach was used to uncover the inducible molecular defense mechanism of cotton root occurring during the compatible interaction with Thielaviopsis basicola. Microscopic observation of cotton root inoculated with a suspension of conidia showed that this necrotrophic hemibiotroph fungus interacts with the plant and completes its life cycle in our experimental system. 2‐DE analysis of root extracts taken after 1, 3, 5, and 7 days postinoculation and cluster analysis of the protein expression levels showed four major profiles (constant, upregulated, one slightly downregulated, and one dramatically downregulated). Spots significantly (p<0.05) upregulated were analyzed by LC‐MS/MS and identified using MASCOT MS/MS ion search software and associated databases. These proteins included defense and stress related proteins, such as pathogenesis‐related proteins and proteins likely to be involved in the oxidative burst, sugar, and nitrogen metabolism as well as amino acid and isoprenoid synthesis. While many of the identified proteins are common components of the defense response of most plants, a proteasome subunit and a protein reported to be induced only in cotton root following Meloidogyne incognita infection were also identified.
A comprehensive analysis of Trypanosoma brucei mitochondrial proteome
Authors: Panigrahi Aswini K. , Ogata Yuko , Zíková Alena , Anupama Atashi , Dalley Rachel A. , Acestor Nathalie , Myler Peter J. , Stuart Kenneth D.
Published: December 2008

The composition of the large, single, mitochondrion (mt) of Trypanosoma brucei was characterized by MS (2‐D LC‐MS/MS and gel‐LC‐MS/MS) analyses. A total of 2897 proteins representing a substantial proportion of procyclic form cellular proteome were identified, which confirmed the validity of the vast majority of gene predictions. The data also showed that the genes annotated as hypothetical (species specific) were overpredicted and that virtually all genes annotated as hypothetical, unlikely are not expressed. By comparing the MS data with genome sequence, 40 genes were identified that were not previously predicted. The data are placed in a publicly available web‐based database (www.TrypsProteome.org). The total mitochondrial proteome is estimated at 1008 proteins, with 401, 196, and 283 assigned to the mt with high, moderate, and lower confidence, respectively. The remaining mitochondrial proteins were estimated by statistical methods although individual assignments could not be made. The identified proteins have predicted roles in macromolecular, metabolic, energy generating, and transport processes providing a comprehensive profile of the protein content and function of the T. brucei mt.
Dissecting the human plasma proteome and inflammatory response biomarkers
Authors: Saha Sudipto , Harrison Scott H. , Chen Jake Yue
Published: December 2008

A central focus of clinical proteomics is to search for biomarkers in plasma for diagnostic and therapeutic use. We studied a set of plasma proteins accessed from the Healthy Human Individual's Integrated Plasma Proteome (HIP2) database, a larger set of curated human proteins, and a subset of inflammatory proteins, for overlap with sets of known protein biomarkers, drug targets, and secreted proteins. Most inflammatory proteins were found to occur in plasma, and over three times the level of biomarkers were found in inflammatory plasma proteins and their interacting protein neighbors compared to the sets of plasma and curated human proteins. Percentage overlaps with Gene Ontology terms were similar between the curated human set and plasma protein set, yet the set of inflammatory plasma proteins had a distinct ontology‐based profile. Most of the major hub proteins within protein‐protein interaction networks of tissue‐specific sets of inflammatory proteins were found to occur in disease pathways. The present study presents a systematic approach for profiling a plasma subproteome's relationship to both its potential range of clinical application and its overlap with complex disease.
Reliability Beyond Theory and Into Practice
Authors: Sijtsma Klaas
Published: December 2008

The critical reactions of Bentler (2009, doi:10.1007/s11336-008-9100-1), Green and Yang (2009a, doi:10.1007/s11336-008-9098-4; 2009b, doi:10.1007/s11336-008-9099-3), and Revelle and Zinbarg (2009, doi:10.1007/s11336-008-9102-z) to Sijtsma’s (2009, doi:10.1007/s11336-008-9101-0) paper on Cronbach’s alpha are addressed. The dissemination of psychometric knowledge among substantive researchers is discussed.
The Floating Lunate: Arthroscopic Treatment of Simultaneous Complete Tears of the Scapholunate and Lunotriquetral Ligaments
Authors: Badia Alejandro , Khanchandani Prakash
Published: December 2008

Carpal instabilities continue to be a controversial topic in hand surgery. Accurate diagnosis of the ligament injuries is usually difficult without an arthroscopic evaluation. Few studies have focused on the diagnosis and proper management of simultaneous scapholunate (SL) and lunotriquetral (LT) ligament tears. This is an uncommon injury that leads to marked disability and chronic wrist pain. This is essentially a “floating lunate” and indicates a severe ligamentous lesion. Thirteen patients (six female and seven male) with complete SL and LT tears and with gross arthroscopic dynamic carpal instability were included in the present study. None of the patients showed radiographic evidence of lunate dislocation. One patient presented acutely and was operated on 3 days after the injury. The average time from the initial injury to the arthroscopy for the other 12 patients was 13.5 months (range 1.5–84 months). All patients underwent arthroscopic debridement of the SL and LT ligaments coupled with percutaneous pinning (two 0.045-in. Kirschner wires) in both joints. At the final follow-up, the average range of motion was 50° of flexion, 54° of extension, 77° of pronation, 80° of supination, 25° of ulnar deviation, and 15° of radial deviation. The average final grip strength was 67% from the non-affected side. All patients had negative shifting tests at final follow-up. Furthermore, there was no evidence of any static or dynamic instability in all the patients except for one patient who developed a volar intercalated segment instability 8 months after the surgery. At the final follow-up, ten patients had no pain, one had mild pain, and two experienced moderate pain.
Performance and stability of performance of spring wheat variety mixtures in organic and conventional management systems in western Canada
Authors: KAUT A. H. E. E. , MASON H. E. , NAVABI A. , O'DONOVAN J. T. , SPANER D.
Published: December 2008

Wheat (Triticum aestivum L.) variety mixtures represent a relatively unexplored avenue for maintaining and stabilizing yield for both organic and conventional producers. The present study examined the responses of three Canadian western red spring wheat varieties in sole crop and in variety mixtures to varying levels of simulated and natural competition, as well as environmental stress at one conventionally and two organically managed locations in central Alberta, Canada, between 2003 and 2005. Three modern hard red spring wheat varieties (Superb, semi-dwarf; AC Intrepid, early maturing and 5600HR, tall), along with 13 two- and three-way variety mixtures, were planted under two levels of simulated weed (Brassica juncea L.) competition at each of the eight location-years. The B. juncea weed competition treatment decreased yields at all locations. Overall yield was lowest at the certified organic farm and highest under conventional management. Sole-crop semi-dwarf Superb and all three Superb–Intrepid mixture entries consistently yielded among the highest, regardless of management system, testing location or competition treatment. The 1:1 and 1:2 Superb–Intrepid mixture entries were the most stable of all entries tested. Early season vigour was strongly associated with yield, with the strongest correlation occurring under low-moisture, low-nutrient, high-competition conditions at the certified organic farm. Spring wheat variety mixtures may provide greater stability with little or no reduction in yield, while providing greater competitive ability.