bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of a New Solid‐Phase Microextraction Fiber by Coating Silylated Nanoporous Silica on a Copper Wire
Authors: Hashemi Payman , Badiei Alireza , Shamizadeh Mohammad , Ziarani Ghodsi Mohammadi , Ghiasvand Ali Reza 
Published: March 2012

AbstractLUS‐1 typed nanoporous silica particles were synthesized and silylated with hexamethyldisilazane and investigated as a highly porous fiber coating for solid‐phase microextraction (SPME). The pore size distribution of the prepared Sil‐LUS‐1 was still typical of MCM‐41 and centered at 3 nm with a specific surface area of 720 m2g−1. The SPME fiber was prepared by liming the material on a copper wire. The extraction efficiency of the new fiber was compared with a commercial PDMS fiber for headspace extraction and GC‐MS analysis of phenol, 4‐nitrophenol, 2,4‐dichlorophenol and 4‐chlorophenol in water samples. Due to the high porosity of the prepared fiber it showed a higher sensitivity and better selectivity for the extraction of the target compounds. For optimization of different factors affecting the extraction efficiency, a simplex optimization method was used. The relative standard deviation for the measurements by one fiber was better than 7% for five replicates and the fiber‐to‐fiber reproducibility was about 10% for five fabricated fibers. Detection limits in the range of 0.002 to 0.026 μg mL−1 were obtained for the phenolic compounds. The fiber was successfully applied for the determination of phenolic compounds in natural water samples.
β‐Enaminonitriles in Heterocyclic Synthesis: Synthesis of New 1,4‐Dihydropyridine, Tetrahydropyridine, Nicotinonitrile and Aminopyrazole Derivatives
Authors: Ramiz Mahmoud M. M. , Abdel Hafiz Ibrahim S. , Elian Mohamed A. 
Published: March 2012

AbstractA series of new pyridine, dihydropyridine, tetrahydropyridine, nicotinonitrile and pyrazole derivatives with expected biological activity were prepared through the reactions of 3‐aminopent‐2‐enenitrile 1 with some electrophilic reagents, nucleophilic reagents, and aryl diazonium salts. The newly synthesized compounds were characterized by IR, 1H‐NMR, 13C‐NMR and mass spectral studies.
Synthesis of (3‐N‐substituted‐piperidin‐4‐ylidene)acetic Acid Ethyl Esters
Authors: Chang Meng‐Yang , Lee Tein‐Wei 
Published: March 2012

AbstractA convenient preparation of skeletons 2A and 2B (cyclic γ,δ‐diamino‐α,β‐unsaturated esters) is reported by a three‐step synthetic route based on a sequence of NBS‐mediated one‐pot α‐bromination/Wittig olefination of piperidin‐4‐one 3, nucleophilic addition with NaN3, and followed by PPh3‐promoted Staudinger reduction/substitution or CuI‐catalyzed Huisgen 1,3‐dipolar cycloaddition.
Leading with metaphoric intelligence
Authors: Nguyen Nhu T. B. , Umemoto Katsuhiro 
Published: March 2012

AbstractThis paper argues that metaphoric intelligence plays a major role in successful leadership. We are embarking on the understanding of metaphoric intelligence by reporting partial research surrounding successful metaphors that can potentially account for metaphoric intelligence. We analyzed recent ideas on the effective use of metaphors by leaders of countries, providing the reader with a useful, convenient base for investigation on the general role of metaphor in leadership, and the role of metaphoric intelligence as manifested in speeches for special purposes in particular. Only the first step in the direction of providing a comprehension of metaphoric intelligence for leadership, this paper opens a number of interesting avenues of future research. In particular, this study calls for more empirical research, especially research focusing on how metaphoric intelligence foster leadership's role in organization.
Eukaryotic life in biofilms formed in a uranium mine
Authors: Zirnstein Isabel , Arnold Thuro , Krawczyk‐Bärsch Evelyn , Jenk Ulf , Bernhard Gert , Röske Isolde 
Published: March 2012

AbstractThe underground uranium mine Königstein (Saxony, Germany), currently in the process of remediation, represents an underground acid mine drainage (AMD) environment, that is, low pH conditions and high concentrations of heavy metals including uranium, in which eye‐catching biofilm formations were observed. During active uranium mining from 1984 to 1990, technical leaching with sulphuric acid was applied underground on‐site resulting in a change of the underground mine environment and initiated the formation of AMD and also the growth of AMD‐related copious biofilms. Biofilms grow underground in the mine galleries in a depth of 250 m (50 m above sea level) either as stalactite‐like slime communities or as acid streamers in the drainage channels. The eukaryotic diversity of these biofilms was analyzed by microscopic investigations and by molecular methods, that is, 18S rDNA PCR, cloning, and sequencing. The biofilm communities of the Königstein environment showed a low eukaryotic biodiversity and consisted of a variety of groups belonging to nine major taxa: ciliates, flagellates, amoebae, heterolobosea, fungi, apicomplexa, stramenopiles, rotifers and arthropoda, and a large number of uncultured eukaryotes, denoted as acidotolerant eukaryotic cluster (AEC). In Königstein, the flagellates Bodo saltans, the stramenopiles Diplophrys archeri, and the phylum of rotifers, class Bdelloidea, were detected for the first time in an AMD environment characterized by high concentrations of uranium. This study shows that not only bacteria and archaea may live in radioactive contaminated environments, but also species of eukaryotes, clearly indicating their potential influence on carbon cycling and metal immobilization within AMD‐affected environment.
Surface movements in a rock massif induced by drainage associated to tunnel excavation
Authors: Mokni N. , Olivella S. , Carrera J. , Otto B. 
Published: March 2012

SUMMARYSurface movements were measured in the Gotthard massif as the Gotthard Base Tunnel was excavated. These movements might damage concrete dams constructed on the surface valleys. The leading assumption of this work is that deformation is induced by the dissipation of pore pressures in the massif caused by tunnel drainage. Deformations induce both horizontal and vertical surface displacements. Horizontal displacements, may lead to valley closures if they are in opposite direction, which would induce negative effects on arch dams. An analytical solution is derived using the method of images and an approximated integration of deformations to calculate the movements and the flow rate collected in the tunnel. Numerical calculations were carried out in 2D (vertical cross section) and 3D to investigate the problem under different conditions and to study the effect of parameters. The 3D models permit to incorporate the presence of a vertical fracture perpendicular to the tunnel that increases the drainage and pressure drop as it is hit by the tunnel. It was also possible to simulate the impermeabilization works in the tunnel to reduce drainage and consequently, movements. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of alignment algorithms with mixed dimensions for dimensionality reduction
Authors: Ye Qiang , Zhi Weifeng 
Published: March 2012

SUMMARYWe consider an alignment algorithm for reconstructing global coordinates of a given data set from coordinates constructed for data points in small local neighborhoods through computing a spectral subspace of an alignment matrix. We show that, under certain conditions, the null space of the alignment matrix recovers global coordinates even when local point sets have different dimensions. This result generalizes a previous analysis to allow alignment of local coordinates of mixed dimensions. We also extend this result to the setting of a semi‐supervised learning problem, and we present several examples to illustrate our results. Copyright © 2012 John Wiley & Sons, Ltd.
miR‐124 inhibits cell proliferation in gastric cancer through down‐regulation of SPHK1
Authors: Xia Jintang , Wu Zhiqiang , Yu Chunping , He Weiling , Zheng Haiqing , He Yulong , Jian Weihua , Chen Lianzhou , Zhang Luanjing , Li Wen 
Published: March 2012

AbstractSPHK1 expression is elevated in gastric cancer and is associated with shorter survival times for patients. However, the molecular mechanism of SPHK1 up‐regulation in gastric cancer remains unclear. In the present study, we report that miR‐124 down‐regulated SPHK1 expression by directly targeting its 3′‐untranslated region (3′‐UTR) and that miR‐124 expression was inversely correlated with SPHK1 expression in gastric cancer samples. Furthermore, we demonstrated that, similar to the effect of silencing SPHK1, up‐regulation of miR‐124 markedly inhibited proliferation and tumourigenicity of gastric cancer cells both in vitro and in vivo. This was found to be mechanistically associated with induction of cyclin‐dependent kinase inhibitors p21$^{{\rm Cip1}}$ and p27$^{{\rm Kip1}}$, enhancement of the transcriptional activity of FOXO1 and suppression of AKT activity. Moreover, we showed that the re‐introduction of SPHK1 (without the 3′‐UTR), but not with the 3′‐UTR, could abrogate the miR‐124‐mediated induction of p21$^{{\rm Cip1}}$ and p27$^{{\rm Kip1}}$, as well as rescue the miR‐124‐induced proliferation inhibition. Together, these results suggest that miR‐124 has an important role in the suppression of gastric cancer and presents a novel mechanism of miRNA‐mediated SPHK1 expression in cancer cells. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A numerical treatment of crystallization in tube flow
Authors: Wo Duane Lee , Tanner Roger I. , Fletcher David F. 
Published: March 2012

AbstractA viscosity‐oriented, flow‐induced crystallization model is used to predict the rate of crystal layer growth in a tube at high shear rates. A combined strain and strain rate dependence of the enhancement of crystallization kinetics was proposed that showed excellent agreement with viscosity measurements at low deformation rates in simple shear, and it is here considered in the more complex Poiseuille flow. Suspension mechanics is used to link the relative crystalline volume fraction to the viscosity of the semicrystalline polymer. The microstructure is directly related to the thermomechanical histories and this was accounted for in the total volume fraction using the Avrami‐Kolmogorov model. The key characteristic of our model is the coupling of the flow history to induced crystallization and the linkage of the flow‐enhanced nucleation with viscosity. In this way, the flow is described in terms of changes in crystallization due to changes in rheological behavior. A finite volume numerical treatment was employed using the ANSYS CFX software to model the layer growth. The model is further tested with the presence of an organic nucleating agent in which the sensitivity of the rheological properties of the pigment–polymer blend to stress and temperature was evident. Reasonable agreement with experiments was observed. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Conformal coating of yarns and wires with electrospun nanofibers
Authors: Dabirian Farzad , Ravandi Seyed Abdolkarim Hosseini , Hinestroza Juan P. , Abuzade Ramazan Ali 
Published: March 2012

AbstractMetal wires and fibrous yarns are often coated with functional polymeric layers aimed at adding certain finishing properties such as abrasion resistance, electrical insulation, or enhanced lubrication. This manuscript demonstrates that by modifying some aspects of typical electrospinning setup, a novel method for nanocoating of textile yarns and copper wires with conformal layers of electrospun nanofibers can be devised. The benefits of the presented experimental setup were evaluated by twisting and wrapping of electrospun nylon nanofibers on the surface of conventionally spun nylon yarns as well as by coating polylactic acid nanofibers on the surface of copper wires. The coating density was found to be influenced by the applied voltage and the take up velocity of the yarn while the alignment of the nanofibers was found to be influenced only by the yarn take up velocity. The presented setup may open a new avenue to provide conformal finishing characteristics to yarns and fibers. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Bubble development in a polymeric resin under vacuum
Authors: Sul In Hwan , Youn Jae Ryoun , Song Young Seok 
Published: March 2012

AbstractUnderstanding the gas diffusion and evaporation behavior in a polymeric resin under vacuum is of great importance because many types of polymer and composite products are manufactured by applying a vacuum to the production system. This article proposes a theoretical model that can describe bubble growth under vacuum by combining the mechanisms of gas diffusion and evaporation. To confirm such a model, we carried out experimental analyses including evaporation experiments with a bell jar or a tube as well as vacuum‐assisted resin transfer molding (VARTM). Particularly in the VARTM process, it was identified that many bubbles were nucleated and grew at the fiber‐matrix interface due to the applied vacuum pressure. Those results suggest that more attention should be paid to vacuum‐assisted material processing to prevent bubbles from existing in the final products. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Rheological properties and morphological evolutions of polypropylene/ethylene‐butene copolymer blends
Authors: Zhang Xian‐Ming , Li Hao , Chen Wen‐Xing , Feng Lian‐Fang 
Published: March 2012

AbstractThis work aims at studying the extensional rheological behavior of polypropylene (PP), ethylene‐butene copolymer (PEB) and their blends in the melt. The weight fraction of the PEB in the blend is 20 and 40%, respectively. Dynamic mechanical analysis shows that these two blends exhibit two tanδ peaks corresponding to the glass transitions of the PP and PEB, respectively. Differential scanning calorimeter results indicate that the presence of the PEB does not alter the melting and crystallization temperatures of the PP. Master curves at 170°C are constructed for the storage and loss modulus as well as complex viscosity. The extensional behavior of the PP, PEB, and their two blends is studied. The PEB enhances the strain hardening of the PP. Changes in the blend morphology during the extensional analysis are also studied. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
In situ synthesis, morphology, and thermal properties of polystyrene—MgAl layered double hydroxide nanocomposites
Authors: Botan Rodrigo , Nogueira Telma Regina , Wypych Fernando , Lona Liliane Maria Ferrareso 
Published: March 2012

AbstractPolystyrene (PS)/layered double hydroxide (LDH) nanocomposites were synthesized by in situ free radical bulk polymerization. LDH formed by magnesium and aluminum (Mg:Al—molar ratio of 2:1) was prepared by coprecipitation method and intercalated with sodium dodecyl sulfate (DDS). The nanocomposites were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and flammability test. The XRD and TEM demonstrated that synthesized nanocomposites in all compositions studied showed a high global dispersion of LDH in PS, suggesting exfoliation. The results of TGAs (when 50% mass loss was selected as a comparison point) and flammability tests for synthesized nanocomposites, presented a significant improvement in thermal stability and flammability property when compared with pure PS. This behavior and properties indicate application of the surfactant intercalated LDH reinforced PS in fields where thermal stability is an important characteristic. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Nanocomposite Thin Films with Hybrid Inorganic/Organic Matrix for the Modification of Silicon‐Based Implants
Authors: Nunes Jorge , Santos Rita J. , Loureiro Vera , Piedade Ana P. 
Published: March 2012

AbstractThin nanocomposite hybrid films were deposited by r.f. magnetron sputtering. These were composed of of SiO2, poly(propylene) (PP) and SiO2/PP, with Ag contents varying from 0 to 30 at.‐%. The influence of metal concentration on the properties of the deposited surfaces was evaluated. The chemical composition, chemical structure, morphology, dynamic wettability behavior, and microstructure were studied. The overall properties of the inorganic/organic system are more influenced by those of the ceramic fraction than by the polymeric one. The hysteresis of the contact angle shows that all the surfaces interact with water and that the presence of the metallic element increases reactivity in an aqueous medium. These results show promising applications in the biomedical field particularly in those that use silicon as a biomaterial for implants. magnified image
Early, Intensified Home‐based Exercise after Total Hip Replacement — A Pilot Study
Authors: Mikkelsen Lone R. , Mikkelsen Søren S. , Christensen Finn B. 
Published: March 2012

AbstractBackground and PurposeDespite a successful surgical procedure, deficits in muscle strength and physical function are documented 1–2 years after total hip replacement (THR). There is a lack of evidence concerning which rehabilitation strategy is the most effective after THR. The purpose of this pilot study was to investigate the feasibility of an early‐initiated intensified, home‐based training regime and to form the basis of future studies with regard to exercises, outcome measures and power calculations.MethodsThe trial is a single‐blinded, cluster‐randomized controlled trial performed at an orthopaedic physiotherapy department in a public hospital in Denmark. A consecutive sample of 46 patients undergoing primary THR surgery for osteoarthritis between September 2008 and January 2009 was included. Forty‐four patients completed the trial (96% follow‐up). Participants were randomly assigned to an intervention group (IG, n = 23) receiving 12 weeks of intensified exercises (e.g. rubber band resistance) or a control group (CG, n = 21) receiving standard rehabilitation exercises without external resistance. The outcome measurements were maximal gait speed, isometric hip abductor muscle strength, one‐legged stance, health‐related quality of life (EuroQol‐5 Dimensions), patient satisfaction, and patient‐evaluated function, stiffness and pain (Western and Ontario McMasters University Osteoarthritis Index).ResultsThere were significant increases in both groups in all the measurements during the 12 weeks of exercises. All participants in the IG were satisfied or very satisfied with the exercises compared with 85% in the CG (P = 0.095). In the IG, four participants (17.4%) had difficulties when performing the intensified exercises at home. Hip abduction strength was significantly weaker in the leg operated compared with the leg not operated on after the intervention in both groups (P < 0.01).ConclusionThis pilot study indicates that the majority of THR patients tolerated early‐initiated intensified exercises without additional pain and with high patient satisfaction. It seems that some of the patients need supervision to perform intensified exercises. Copyright © 2012 John Wiley & Sons, Ltd.
Marriage Postponement in Iran: Accounting for Socio‐economic and Cultural Change in Time and Space
Authors: Torabi Fatemeh , Baschieri Angela , Clarke Lynda , Abbasi‐Shavazi Mohammad Jalal 
Published: March 2012

ABSTRACTThe mean age at marriage of Iranian women increased by three years between the mid‐1980s and 2000 during a period of great socio‐economic change, particularly affecting the 1971–1975 and 1976–1980 birth cohorts. This paper analyses the marriage timing and life course experience of these cohorts of women and highlights the contribution that ethnicity and changes in the socio‐economic context made to the sharp marriage delay experienced by the 1976–1980 birth cohort. A discrete time hazard model is applied to the 2000 Iran Demographic and Health Survey data, which are linked to a range of time‐varying district‐level contextual variables created from the 1986 and 1996 Iranian censuses. The findings suggest that the marriage postponement experienced by the younger birth cohort is related to improvements in women's education and can partly be explained by the increased opportunity costs of marriage, which resulted from limited access to education after marriage. The findings also suggest that differences in marriage timing between areas predominated by certain ethnic groups became less evident for the younger birth cohort. Copyright © 2012 John Wiley & Sons, Ltd.
On‐chip control of magnetic particles
Authors: Rinklin Philipp , Krause Hans‐Joachim , Wolfrum Bernhard 
Published: March 2012

AbstractWe describe an on‐chip system to control the actuation of micrometer‐ and nanometer‐sized magnetic particles. Orthogonal conducting microwire arrays are used to induce magnetic fields with highly localized peaks and strong local gradients. These fields are then applied in actuation experiments to generate defined particle movement with micrometer precision. We examine different types of current sequences to efficiently move and separate the particle cloud on the chip without the use of external magnets. The final protocol allows efficient and reliable control over the particle cloud's position minimizing the loss of particles during the individual switching steps.magnified image
Schematic of a microwire chip controlling a cloud of particles (black). The chips are processed on silicon (blue). The microwires consist of Au (yellow) and are insulated with an oxide nitride passivation layer (green transparent).
Detection of L‐nicotine with dissipation mode quartz crystal microbalance using molecular imprinted polymers
Authors: Alenus Jan , Galar Pavel , Ethirajan Anitha , Horemans Frederik , Weustenraed Ans , Cleij Thomas J. , Wagner Patrick 
Published: March 2012

AbstractSynthetic materials with imprinted nanocavities can act as highly selective tailor‐made artificial receptors. Implementing these materials in a piezoelectric sensing device can offer fast and straightforward detection together with high sensitivity. L‐nicotine, a major addictive substance in cigarettes is used as target molecule. The synthetic receptors for L‐nicotine are made via the molecular imprinting technique. The target molecule is added to a monomer mixture containing initiator and this mixture is polymerized with heat. Subsequently, microparticles are obtained by crushing the bulk molecular imprinted polymers (MIPs), which are then immobilized on thin films of polyvinyl chloride. Using Quartz crystal microbalance, L‐nicotine could be detected in the submicromolar range and the selectivity of the sensors was verified by reference measurements with L‐cotinine. The effectiveness of the sensor was also tested for different aqueous fluids at different pH. It was found that MIPs bind 4.03 times more L‐nicotine than non‐imprinted polymer in water and 1.99 times more in 0.1× phosphate buffer saline at pH 9.