bluuebunny/crossref_metadata_2025 huggingface dataset:
Repair of electrically injured median nerve with the aid of somatosensory evoked potential
Authors: Gu Bin , Xie Feng , Jiang Hao , Shen Guoxiong , Li Qingfeng
Published: March 2009

In repair of the high voltage electrical injuries of peripheral nerve, selection of the proper plane for nerve coaptation after debridement is important since the electrical current is inclined to pass through the nerve trunks due to the lower electric resistance. In this report, we present our experience on use of the somatosensory evoked potentials (SSEP) test to assist determination of range of the injured nerve debridement in the electrical injured nerve. From January 1997 to December 2007, 30 patients with the high voltage electrical injury in the wrist, having defect of median nerve, were treated with nerve grafting. In 18 patients, the nerve resection plane was selected with the assistance of SSEP. In 12 patients, the nerve resection plane was determined by the traditional gross examination. The average lengths of nerve defect after debridement were 10.4 cm in the procedure with SSEP assistance and 4.01 cm in the traditional procedure. The finger motion was reconstructed by the tendon graft connecting the proximal forearm muscle and the distal tendon of flexor disitorum profundus. In following up, the two‐point discrimination of finger was examined. The grade of finger sensory recovery was found improved in the patients who underwent the nerve repair with SSEP assistance than that in the patients underwent treatment with the traditional method. The results suggested that aggressive debridement is recommended for the high with voltage electrical nerve injury. SSEP could be a valuable tool for determination of the range of nerve debridement. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
Effects of acetylo‐L‐carnitine in end‐to‐side neurorrhaphy: A pilot study
Authors: Kostopoulos Vasileios K. , Davis Christin L. , Terzis Julia K.
Published: March 2009

Purpose: End‐to‐side (ETS) nerve repair allows for target‐muscle reinnervation, with simultaneous preservation of donor‐nerve function. Acetyl‐L‐carnitine (ALCAR) was shown to enhance axonal sprouting in early regeneration following transection and repair of the sciatic nerve in rodents. The purpose of this article was to determine the ability of ALCAR to enhance axonal regeneration in an ETS rodent model. Method: The right musculocutaneous nerve in 16 adult male Sprague‐Dawley rats was transected to induce biceps muscle paralysis. The distal stump was then coapted by ETS neurorrhaphy through a perineurial window to the ipsilateral median nerve. Experimental groups received ALCAR for 1, 2, 3, and 4 weeks whereas controls received placebo. Results: Weekly postoperative behavioral evaluations revealed increased functional return over control but the difference was not significant. Potentials from biceps were recorded from the third postoperative week in the experimental group and from the fourth week in the control group. Histomorphometric evaluations revealed higher musculocutaneous nerve axon counts, higher myelin thickness in the fourth postoperative week, and differences in the appearance and the number of motor‐end‐plates in the biceps in experimental versus control group. Conclusion: Intraperitoneal administration of ALCAR can expedite biceps muscle recovery in an ETS model by increasing the rate of axonal regeneration. Despite the morphological changes, no behavioral changes were noted and further studies are needed to confirm clinical efficacy of ALCAR for potential use in the development of therapeutic protocols. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.
Protein‐free ligand screening: simplification of chiral chromatographic development via novel adaptation of NMR screening methodologies
Authors: Thompson Melissa R. , McKenzie David R. , Likos John J. , Gard Janice K.
Published: March 2009

We demonstrate here a promising NMR method that provides evidence for chiral compound selector interaction as a first‐pass screening method. A novel adaptation of commonly used protein‐based screening technologies, this approach relies upon ligand‐to‐stationary phase interaction wherein the stationary phase is tethered to sepharose beads. At only minutes per experiment, this methodology significantly reduces the time required for chiral separation methodology development and complements currently available chromatographic purity technologies.Copyright © 2009 John Wiley & Sons, Ltd.
Metabonomic identification of novel biomarkers in doxorubicin cardiotoxicity and protective effect of the natural antioxidant oleuropein
Authors: Andreadou Ioanna , Papaefthimiou Maria , Zira Athina , Constantinou Maria , Sigala Fragiska , Skaltsounis Alexios‐Leandros , Tsantili‐Kakoulidou Anna , Iliodromitis Efstathios K. , Kremastinos Dimitrios T. , Mikros Emmanuel
Published: March 2009

Doxorubicin (DXR) is a commonly used antineoplastic agent; however, its use is limited due to cardiotoxicity. Oxidative stress and consequent alterations of cardiac energetics are involved in the development of DXR toxicity. Oleuropein (Oleu) is a phenolic antioxidant, present in olive tree, reported to confer protection against DXR cardiotoxicity. In this study, NMR based‐metabonomics was applied to characterize the metabolic profile of the acute DXR cardiotoxicity in rats and to evaluate the metabolic alterations conferred by co‐treatment with Oleu. Wistar rats were divided into six groups and treated as follows: control group with a single injection of 2 mL normal saline intraperitoneally (i.p.), DXR group with a single dose of 20 mg/kg, i.p and DXR plus Oleu groups with 20mg/kg DXR i.p., and 100 or 200 mg/kg/BW of Oleu i.p. for 5 or 3 consecutive days starting either 2 days before or on the day of DXR administration. Hearts were excised 72 h after DXR treatment and1H‐NMR spectra of aqueous myocardium extracts were recorded. Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS‐DA) revealed differences in the metabolic profile between control and DXR attributed to several metabolites. A number of them were quantified by integration of the NMR spectra. Myocardial levels of acetate and succinate were increased in DXR compared to controls, while branched amino acids were decreased. These results correlate with nonenzymatic conversion of pyruvate to acetate and ofα‐ketoglutarate to succinate by DXR free radicals. Oleu completely restored the changes of metabolites to the normal levels. Acetate and succinate constitute novel biomarkers related to DXR, and Oleu treatment aids the compensation of distressed energy metabolic pathways. Copyright © 2009 John Wiley & Sons, Ltd.
Combined equivalent charge formulations and fast wavelet Galerkin BEM for 3‐D electrostatic analysis
Authors: Xiao Jinyou , Tausch Johannes , Cao Yanchuang , Wen Lihua
Published: March 2009

We describe a new equivalent charge formulation (ECF), i.e. the combined ECF (CECF), for electrostatic analysis of structures consisting of conductors and dielectrics. The CECF uses a weighted combination of the single‐ and the adjoint double‐layer operators to account for the potential on the conductor–dielectric surface and is found to have better conditioning than the standard ECF. A perturbation approach is presented to insure that the capacitances are computed accurately even when the permittivity ratios of the dielectrics are vary large. Unlike the original perturbation approach, this new approach uses only one system matrix with different right‐hand sides.

A wavelet Galerkin boundary element method (WGBEM) for solving the ECF and CECF is developed based on the new variable‐order WGBEM introduced in (J. Numer. Math. 2004; 12(3):233–254). The wavelets are directly constructed on the usual boundary element triangulation. This enables the proposed WGBEM to solve electrostatic problems in complicated geometries, unstructured meshes and comparatively coarse discretizations. The quasi‐vanishing moment wavelets introduced in (Comput. Methods Appl. Mech. Engng 2008; 197:4000–4006) are used to further reduce the memory and CPU time requirements.

Several numerical examples show that the proposed CECF converges faster than the ECF, and that the WGBEM, using both the ECF and CECF, has almost linear complexity in solving large‐scale 3‐D electrostatic problems. Moreover, since the truncated non‐standard form is computed once and then stored, the WGBEM is very suitable for solving problems with multiple right‐hand sides, like the perturbation approach in this paper. Copyright © 2009 John Wiley & Sons, Ltd.
Finite strain, finite rotation quadratic tetrahedral element for the combined finite–discrete element method
Authors: Xiang Jiansheng , Munjiza Antonio , Latham John‐Paul
Published: March 2009

In the past, the combined finite–discrete element was mostly based on linear tetrahedral finite elements. Locking problems associated with this element can seriously degrade the accuracy of their simulations. In this work an efficient ten‐noded quadratic element is developed in a format suitable for the combined finite–discrete element method (FEMDEM). The so‐called F‐bar approach is used to relax volumetric locking and an explicit finite element analysis is employed. A thorough validation of the numerical method is presented including five static and four dynamic examples with different loading, boundary conditions, and materials. The advantages of the new higher‐order tetrahedral element are illustrated when brought together with contact detection and contact interaction capability within a new fully 3D FEMDEM formulation. An application comparing stresses generated within two drop experiments involving different unit specimens called Vcross and VRcross is shown. The Vcross and VRcross units of ∼3.5 × 104kg show very different stress generation implying different survivability upon collision with a deformable floor. The test case shows the FEMDEM method has the capability to tackle the dynamics of complex‐shaped geometries and massive multi‐body granular systems typical of concrete armour and rock armour layers. Copyright © 2009 John Wiley & Sons, Ltd.
Lagrangian mechanics and variational integrators on two‐spheres
Authors: Lee Taeyoung , Leok Melvin , McClamroch N. Harris
Published: March 2009

Euler–Lagrange equations and variational integrators are developed for Lagrangian mechanical systems evolving on a product of two‐spheres. The geometric structure of a product of two‐spheres is carefully considered in order to obtain global equations of motion. Both continuous equations of motion and variational integrators completely avoid the singularities and complexities introduced by local parameterizations or explicit constraints. We derive global expressions for the Euler–Lagrange equations on two‐spheres, which are more compact than existing equations written in terms of angles. Since the variational integrators are derived from Hamilton's principle, they preserve the geometric features of the dynamics such as symplecticity, momentum maps, or total energy, as well as the structure of the configuration manifold. Computational properties of the variational integrators are illustrated for several mechanical systems. In addition, Lie group variational integrators can be used to integrate Lagrangian flows on more general homogeneous spaces. This is achieved by lifting the discrete Hamilton's principle on homogeneous spaces to a discrete variational principle on the Lie group that is constrained by a discrete connection. Copyright © 2009 John Wiley & Sons, Ltd.
Small polyhedron reconnection for mesh improvement and its implementation based on advancing front technique
Authors: Liu Jianfei , Chen Y. Q. , Sun S. L.
Published: March 2009

Local transformation, or topological reconnection, is one of the effective procedures for mesh improvement method, especially for three‐dimensional tetrahedral mesh. The most frequently used local transformations for tetrahedral mesh are so‐called elementary flips, such as 2‐3 flip, 3‐2 flip, 2‐2 flip, and 4‐4 flip. Owing to the reason that these basic transformations simply make a selection from several possible configurations within a relatively small region, the improvement of mesh quality is confined. In order to further improve the quality of mesh, the authors recently suggested a new local transformation operation, small polyhedron reconnection (SPR) operation, which seeks for the optimal tetrahedralization of a polyhedron with a certain number of nodes and faces (typically composed of 20–40 tetrahedral elements).

This paper is an implementation of the suggested method. The whole process to improve the mesh quality by SPR operation is presented; in addition, some strategies, similar to those used in advancing front technique, are introduced to speed up the operation. The numerical experiment shows that SPR operation is quite effective in mesh improvement and more suitable than elementary flips when combined with smoothing approach. The operation can be applied to practical problems, gaining high mesh quality with acceptable cost for computational time. Copyright © 2009 John Wiley & Sons, Ltd.
Congenital glioblastoma
Authors: Milano G.M. , Cerri C. , Ferruzzi V. , Capolsini I. , Mastrodicasa E. , Genitori L. , Aversa F.
Published: March 2009

We describe the case a 2‐day‐old female with congenital glioblastoma. Total resection was followed by adjuvant and high dose chemotherapy, as indicated by the current Italian infant protocol. The child is alive and well 18 months after diagnosis. A review of 67 selected congenital brain tumors showed the mortality rate was 82%. Even though the majority of patients had glioblastoma, only 5/67 had received adjuvant therapy. To ensure optimal outcomes, we recommend total or subtotal surgical resection, followed by adjuvant and high dose chemotherapy. Given the lack specific protocols for congenital brain tumors an international consensus seems to be needed, starting with congenital glioblastoma. Pediatr Blood Cancer 2009;53:124–126. © 2009 Wiley‐Liss, Inc.
Negative correlation between cerebrospinal fluid tau protein and cognitive functioning in children with acute lymphoblastic leukemia
Authors: Protas Piotr T. , Muszynska‐Roslan Katarzyna , Holownia Adam , Grabowska Aleksandra , Wielgat Przemyslaw , Krawczuk‐Rybak Maryna , Braszko Jan J.
Published: March 2009

The aim of the study was to assess whether cerebrospinal fluid tau protein is associated with cognitive changes in children with acute lymphoblastic leukemia (ALL). Examination of 38 ALL patients revealed a statistically significant increase in tau protein on treatment day 59 and at two points during consolidation phase. Cognitive functioning was examined in 19 patients at an average of 3.7 years after diagnosis. The level of tau at the initiation of maintenance therapy was negatively correlated with verbal abilities measured on an intellectual scale. The study suggests that standard ALL treatment may cause a decline in cognitive functioning. Pediatr Blood Cancer 2009;53:105–108. © 2009 Wiley‐Liss, Inc.
Synthesis of conducting polyaniline‐montmorillonite nanocomposites via inverse emulsion polymerization in supercritical carbon dioxide
Authors: Sun Fu , Pan Yuejin , Wang Jing , Wang Zi , Hu Chunpu , Dong Qingzhi
Published: March 2009

A new inverse emulsion polymerization and intercalation procedure in supercritical carbon dioxide (SCCO2) was initially employed to synthesize polyaniline‐montmorillonite (PANI‐MMT) nanocomposites. The effect of chemical groups in MMT galleries on intercalation in SCCO2 was investigated. The MMTs modified by different organic cationic surfactants were incorporated into the composite particles, and in unintercalated, partially delaminated or fully exfoliated state. The aminated MMT or fluorinated MMT were utilized to prepare conducting PANI‐MMT nanocomposites with highly concentrated (12–25 wt% loading to monomer), fully exfoliated MMT platelets in SCCO2. The structure and morphology of PANI‐MMT nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffraction pattern (XRD), and transmission electron microscope (TEM). Thermogravimetry analysis (TGA) was performed to demonstrate the enhancement of thermal stability of the composites. SCCO2 was shown to be more effective for impregnation, disaggregation and exfoliation of MMTs than isooctane, which indicates that SCCO2 is an alternative solvent for synthesis of some intercalated composite materials, not only based on the environmental friendly characteristic of SCCO2, but also owing to that SCCO2 can play an important role in intercalative polymerization. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Random discontinuous carbon fiber preforms: Experimental permeability characterization and local modeling
Authors: Endruweit A. , Harper L.T. , Turner T.A. , Warrior N.A. , Long A.C.
Published: March 2009

Injection experiments indicate that for random discontinuous carbon fiber preforms, increasingly uneven flow fronts develop with increasing fiber bundle length and filament count. While at high propensity for fiber bundle splitting, the preform permeability increases continuously with increasing fiber length, no trend can be identified at low propensity. No clear influence of the virgin bundle filament count on the preform permeability was observed. Types of sizing used on the fibers and bundle cross‐sectional shapes may vary and affect the intrinsic filamentization behavior, thus dominating the preform permeability. In a model for local preform permeability, interbundle voids, distributed randomly across the preform thickness, are approximated via a regular void structure. Simulated filling patterns are qualitatively similar to those observed experimentally, showing more pronounced features than those derived from a model based on local through‐thickness homogenization of the filament distribution. A model based on an alternating arrangement of fiber bundles and voids allows prediction of global preform permeability values from series of injection simulations, showing quantitatively better agreement with corresponding experimental results than the homogenization model. For global permeability, agreement between simulated and experimental mean values improves with increasing fiber volume fraction, whereas calculated coefficients of variation show no strong dependence on the fiber volume fraction. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Effects of organoclay on morphology and properties of nanocomposites based on LDPE/PA‐6 blends without and with SEBS‐g‐MA compatibilizer
Authors: Filippi Sara , Dintcheva Nadka Tzankova , Scaffaro Roberto , La Mantia Francesco Paolo , Polacco Giovanni , Magagnini Pierluigi
Published: March 2009

LDPE/PA‐6 blends (75/25 wt/wt) were added with SEBS‐g‐MA (S) and/or an organoclay (20A) using different compounding sequences and the morphology and the properties of the blends or composites were investigated. An XRD study of the nanocomposites with pure polymers showed that 20A is intercalated by LDPE or PA‐6 chains, whereas it is exfoliated by S if the clay concentration does not exceed 10 wt%. The SEM investigation showed that both S and 20A behave as efficient emulsifying agents for the LDPE/PA‐6 blends. However, their effect on the mechanical properties was found to be opposite: S enhanced toughness but lowered the stiffness, whereas 20A improved the elastic modulus but impaired the impact properties. When used together, these additives failed to have synergistic effects and the blends mechanical properties could not be improved strongly. A possible interpretation for this behavior was suggested, considering that the anhydride groups of S can competitively interact with the amine end groups of PA‐6 and with the surface of the silicate layer of 20A. Nevertheless, an optimization of the compounding procedure and the use of appropriate proportions of S and 20A allow the preparation of composites with excellent morphology and a satisfactory balance of stiffness and toughness. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
In‐situ polymerization of polyamide 66 nanocomposites utilizing interfacial polycondensation, Part 1: Organoclay nanocomposites
Authors: Kalkan Zehra S. , Goettler Lloyd A.
Published: March 2009

Effective dispersion of organically modified montmorillonite‐layered silicates in nylon 66 is addressed by synthesizing nanocomposites in situ via interfacial polycondensation from a suspension of silicate platelets in one of the monomer phases using either a stirred or unstirred reactor, while avoiding the detrimental heat history associated with melt compounding of this high melting polymer system. The effects of mixing methodology, reaction conditions, concentration ratio, and clay content are evaluated to elucidate process mechanisms and produce high molecular weight product. Enhanced stiffness of the nanocomposites measured by tensile modulus is related to their nanoscale morphology as characterized by transmission electron microscopy and wide angle X‐ray diffraction. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Effect of the type of carbon nanotubes on tribological properties of polyamide 6
Authors: Giraldo Luis F. , López Betty L. , Brostow Witold
Published: March 2009

Multiwalled carbon nanotubes have been synthesized by catalytic chemical vapor deposition of ethylene, using two different catalysts in order to obtain nanotubes with average diameters of 24 and 58 nm, and different lengths. Polyamide 6 (PA6) was reinforced by melt‐mixing in an extruder with 2 wt% functionalized and unfunctionalized carbon nanotubes (CNTs). The nanocomposites were characterized by thermogravimetric analysis, differential scanning calorimetry, and sliding wear determination (SWD). SWD results show a reduction of the residual depth in a scratch test. The reduction is larger in the presence of unfunctionalized CNTs. A further reduction is obtained when decreasing the nanotubes diameter, an effect which is related to larger interfaces between the nanotube and polymeric matrix. CNTs enhance the crystallinity of the polymer and act as nucleation sites, thus increasing the crystallization temperature in respect to neat PA6. The addition of carbon nanotubes helps the formation of PA6 in α‐crystalline form, which is thermodynamically more stable that the γ‐form. CNTs also can act as heterogeneous nucleation sites, hampering the movement of the polymer chains and increasing the crystallization temperature. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
The neuropsychology of borderline personality disorder: A preliminary study on the predictive variance of neuropsychological tests vs. personality trait dimensions
Authors: Black Donald W. , Forbush Kelsie T. , Langer Amie , Shaw Martha , Graeber Margarita A. , Moser David J. , Bayless John , Watson David , Hovick Lauren , Meyer Vanessa J. , Blum Nancee
Published: March 2009

Borderline personality disorder (BPD) has been associated both with frontolimbic dysfunction and maladaptive personality traits such as impulsivity and neuroticism. The purpose of this study was to examine whether there are differences in predictive variance between neuropsychological variables and selected personality traits in persons with BPD. We compared persons with DSM‐IV BPD (n = 25) to individuals without BPD or substance abuse (n = 20). All subjects completed a battery of neuropsychological tests, Cloninger's Temperament and Character Inventory, and the Barratt Impulsiveness Scale. BPD subjects had evidence of cognitive inhibition, and deficits in working memory, perseveration, and decision‐making not accounted for by IQ differences between groups. In particular, Stroop Interference remained significant after controlling for IQ, depression and alcohol use (p = 0.043). They also had higher levels of impulsivity, novelty seeking and harm avoidance, but lower levels of self‐directedness and cooperativeness than the comparison group. Logistic regression analyses indicated that both personality traits (Nagelkerke R2 = 0.74, Model χ2 = 36.21, p < 0.001) and neuropsychological tests (Nagelkerke R2 = 0. 47, Model χ2 = 19.22, p < 0.001) were significant predictors of BPD. However, neuropsychological tests did not add significant incremental variance over selected personality trait dimensions in predicting BPD (Block χ2 = 6.45, p = 0.168), whereas personality traits added significant incremental variance over neuropsychological tests in predicting BPD (Block χ2 = 3.44, p < 0.001). This study suggests that persons with BPD have impaired neuropsychological performance, but that impulsivity and other selected personality traits have a primary role in predicting BPD over and above neuropsychological test abnormalities. Copyright © 2009 John Wiley & Sons, Ltd.
On structural and spectroscopic differences between quinoline‐2‐carboxamides and theirN‐oxides in the solution and solid state
Authors: Kamiński Radosław , Schilf Wojciech , Cmoch Piotr , Dziembowska Teresa , Woźniak Krzysztof
Published: March 2009

Intramolecular hydrogen bonding in the primarily and secondarily substituted quinoline‐2‐carboxamides and theirN‐oxides has been studied in the solution by multinuclear NMR spectroscopy. Hydrogen bonding patterns and supramolecular arrangement in the solid state have been determined by single crystal X‐ray analysis. In quinoline‐2‐carboxamides weak, nonlinear intramolecular NH…N hydrogen bond is present, but in the solid state the intermolecular hydrogen bonds and packing forces are the factors that decide on the properties of 3D structures. In quinoline‐2‐carboxamideN‐oxides the most important structural features are the intramolecular hydrogen bonds. Details of different weak interactions and resulting 3D arrangement of molecules are discussed.

In the solution, two separate1H signals are observed for the primary quinoline‐2‐carboxamides in the range fromca. 5.8 to 8.1 ppm. The chemical shifts of the NH group's proton for studied R′‐quinoline‐2‐R‐carboxamides are in the range from 8.1 to 8.4 ppm. For theN‐oxide of 4‐R′‐quinoline‐2‐carboxamides (R′ = H, Me, OPh, Cl and Br), the values of the proton chemical shifts of the NH group in the range from 10.78 to 11.38 ppm (for primary amides) indicating that this group forms hydrogen bonds with the oxygen of theN‐oxide group. This bond is stronger than the NH…N bond in quinoline‐2‐carboxamides. For the secondary amideN‐oxides, theδ(NH) values are increasing from 11.25 to 11.77 ppm in the sequence of substituents 4‐Br < 4‐Cl < 4‐H < 4‐Me < 4‐OPh. For 4‐substituted compounds these values depend also on the substituent effect. Copyright © 2009 John Wiley & Sons, Ltd.
Photochromism of new unsymmetrical isomeric diarylethenes bearing a methoxyl group
Authors: Pu Shouzhi , Liu Weijun , Miao Wenjuan
Published: March 2009

Three new unsymmetrical isomeric diarylethenes having a methoxyl substituent at ortho‐, meta‐, and para‐position of the terminal benzene ring, namely 1‐(2,5‐dimethyl‐3‐thienyl)‐2‐[2‐methyl‐5‐(2‐methoxylphenyl)‐3‐thienyl]perfluorocyclopentene (1o), 1‐(2,5‐dimethyl‐3‐thienyl)‐2‐[2‐methyl‐5‐(3‐methoxylphenyl)‐3‐thienyl]perfluorocyclopentene (2o), and 1‐(2,5‐dimethyl‐3‐ thienyl)‐2‐[2‐methyl‐5‐(4‐methoxylphenyl)‐3‐thienyl]perfluorocyclopentene (3o), have been synthesized. The substituent position effect of methoxyl group on their properties, including photochromism and fluorescence both in hexane solution and in PMMA film, and their electrochemical properties, were investigated in detail. These diarylethenes showed good photochromism both in solution and in PMMA film. For the same photochromic diarylethene backbone, the electron‐ donating methoxyl substituent can effectively depress the cyclization quantum yields and increase the cycloreversion quantum yields compared to those of diarylethenes bearing chlorine atoms reported previously. Diarylethenes 1o–3o showed clear fluorescent switches by photoirradiation both in hexane and in PMMA film. In addition, cyclic voltammetry tests showed that the electron‐donating methoxyl group at different position on the terminal benzene ring had a significant effect on the electrochemical properties of these isomeric diarylethenes. Copyright © 2009 John Wiley & Sons, Ltd.
The importance of reliable inertisation and grounding of ignition sensitive powder handling systems
Authors: Roper Bill
Published: March 2009

A fire occurred in a powder handling facility handling highly ignition sensitive organic powders used as antioxidants for the plastics industry. Fortunately little damage was done and no one was injured. The incident was investigated and the facts examined with conclusions made as to the possible causes. The incident may have been prevented had production management set in place a set of regular controls, carried out by the process operators themselves, to ensure integrity of equipment designed to ensure the safety of the system. This article describes the basics of such a Safety Maintenance and Control (SAMACO) system. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009
Improvements in the safety screening of resin manufacturing processes
Authors: Kalfas George , Krieger Todd , Wilcox Ross
Published: March 2009

Consequences of acrylic resin reactor runaways can be devastating, as it is evident in investigation reports of industrial accidents. Critical in preventing major accidents is the safety screening of any acrylic resin formula to be manufactured in large scale. Computer model simulations facilitate the evaluation of “layers of protection” against acrylic polymerization runaways. This work describes the adaptation of a chemical process dynamic simulator (DuPont™ TMODS™) for use in simulating acrylic polymerization runaways. “Loss of cooling” and “monomer pooling (accumulation)” scenarios are the causes of these runaways. Simulations show that scenarios leading to “monomer pooling” result in more energetic runaways and to larger emergency relief capacity requirements than “loss of cooling” scenarios. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009
Membrane permeability and antimicrobial kinetics of cecropin P1 against Escherichia coli
Authors: Arcidiacono Steven , Soares Jason W. , Meehan Alexa M. , Marek Patrick , Kirby Romy
Published: March 2009

The interaction of cecropin P1 (CP1) with Escherichiacoli was investigated to gain insight into the time‐dependent antimicrobial action. Biophysical characterizations of CP1 with whole bacterial cells were performed using both fluorescent and colorimetric assays to investigate the role of membrane permeability and lipopolysaccharide (LPS) binding in lytic behavior. The kinetics of CP1 growth inhibition assays indicated a minimal inhibitory concentration (MIC) of 3 µM. Bactericidal kinetics at the MIC indicated rapid killing of E.coli (<30 min). Membrane permeability studies illustrated permeation as a time‐dependent event. Maximum permeability at the MIC occurred within 30 min, which correlates to the bactericidal action. Further investigation showed that the immediate permeabilizing action of CP1 is concentration‐dependent, which correlates to the concentration‐dependent nature of the inhibition assays. At the MIC and above, the immediate permeability was significant enough that the cells could not recover and exhibit growth. Below the MIC, immediate permeability was evident, but the level was insufficient to inhibit growth. Dansyl polymyxin B displacement studies showed LPS binding is essentially the same at all concentrations investigated. However, it does appear that only the immediate interaction is important, because binding continued to increase over time beyond cell viability. Our studies correlated CP1 bactericidal kinetics to membrane permeability suggesting CP1 concentration‐dependent killing is driven by the extent of the immediate permeabilizing action of the peptide. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Immobilization strategies for small molecule, peptide and protein microarrays
Authors: Köhn Maja
Published: March 2009

Protein, peptide and small molecule microarrays are valuable tools in biological research. In the last decade, substantial progress has been achieved to make these powerful technologies more reliable and available for researchers. This review describes chemical preparation methods for these microarrays with focus on site‐selective and bioorthogonal immobilization reactions, particularly the Staudinger ligation and the thiol‐ene reaction. In addition, the application of peptide microarrays, which were prepared by Staudinger ligation, to substrate specificity mapping is illustrated. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
RE (RE = Sm, Eu, Gd)‐doped CeO2 single buffer layers for coated conductors prepared by chemical solution deposition
Authors: Sun Ruiping , Pu Minghua , Li Guo , Wang Wentao , Pan Min , Zhang Hong , Lei Ming , Wu Wei , Zhang Xin , Yang Ye , Zhang Yong , Zhao Yong
Published: March 2009

Textured RE (RE = Sm, Eu, Gd)‐doped CeO2 single buffer layers for coated conductors were prepared by a polymer assisted chemical solution deposition (PACSD) approach. The as‐grown buffer layers on biaxially textured NiW(5%) alloy tapes were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM) as well as atomic force microscopy (AFM). The thicknesses of these buffer layers have been determined to be over 150 nm, on which a YBCO film has been deposited with an onset transition temperature above 90 K and a critical current density of 1 MA cm–2. These results indicate that RE doping can increase the critical thickness of CeO2 and PACSD may be a cost‐effective way to deposit CeO2. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence investigation of zinc molybdate single crystals
Authors: Spassky Dmitry , Vasil'ev Andrey , Kamenskikh Irina , Kolobanov Vitaly , Mikhailin Vitaly , Savon Alexander , Ivleva Ludmila , Voronina Irina , Berezovskaya Ludmila
Published: March 2009

Zinc molybdate is considered as an alternative to the sheelite‐type molybdate crystals for cryogenic scintillating bolometers. We report the results of the first investigation of the luminescent properties of bulk ZnMoO4 single crystals grown by Czochralski method. The temperature dependence of the luminescence intensity under different excitation energies was studied, optical characteristics of zinc molybdate are presented. The potential of ZnMoO4 single crystal as a scintillating material at low temperature is demonstrated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Semiempirical equation of the levitation‐force density for (Sm123)1–x(Yb211)x superconducting samples
Authors: Çelik Ş. , Öztürk K.
Published: March 2009

After the preparation of Sm123 and Yb211 by melt‐powder‐melt growth and solid‐state‐reaction, respectively, the nominal compositions of (Sm123)1–x (Yb211)x for x = 0.00, 0.05, 0.10, 0.15, 0.20 and 0.25 were prepared to examine experimentally and theoretically the effect of x in the composition on the levitation‐force density. Although the amount of Yb211 increased on increasing the content x, the levitation‐force density increased because the Yb211 phase structure decomposed into Yb123 and liquid phase. Owing to the fact that Yb123 welded the Sm123 grains under a slow‐cooling regime, the increasing of the interaction between Sm123 grains gave rise to high potential barriers of the flux pinning and resulted in increasing of the levitation‐force density with the content x. The results of the obtained general functions of the levitation‐force density for all samples are in good agreement with the experimental data. This new formulation of the levitation‐force density is very useful for material optimization to other researchers. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Printable electronics: flexibility for the future
Authors: Leenen Mark A. M. , Arning Volker , Thiem Heiko , Steiger Jürgen , Anselmann Ralf
Published: March 2009

Printed electronics is an emerging technology with huge potential. Market studies predict a multi‐billion dollar market size within less than 5 years. Due to its compatibility with flexible substrates and low‐cost fabrication, printed electronics is able to bring electronic functionality to markets unfit for rigid and expensive silicon electronics. Key to its success are innovative printing technologies and high‐quality material systems, engineered for specific device applications. Printed electronics is a complex multidisciplinary research area, with still a number of fundamental problems to be solved before the technology can grow to its full potential. Evonik Industries is involved in the development of printed electronics through its unique science‐to‐business concept. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of a contacting scheme for self‐assembled cleaved edge overgrown InAs nanowires and quantum dot arrays
Authors: Fehr Matthias , Uccelli Emanuele , Dasgupta Shivaji , Bichler Max , Steinke Lucia , Abstreiter Gerhard , Grayson Matthew , Morral Anna Fontcuberta i
Published: March 2009

A contacting scheme to measure the transport properties into self‐assembled InAs Quantum Wires (QWRs) or Quantum Dots (QDs) is presented. The nanostructures are formed on the (110) cleaved edge of a AlAs/AlGaAs heterostructure substrate by means of the Cleaved Edge Overgrowth (CEO) technique and Molecular Beam Epitaxy (MBE). The InAs nanostructure grows directly on top of the AlAs layer, which hosts a two dimensional electron gas (2DEG). In a transistor‐like schematic of the device, the 2DEG acts as a contact to the InAs nanostructure. A top gate is used to deplete the 2DEG, thereby defining the InAs nanostructure as a channel between source and drain. Measurements confirm that the device can be operated as a field‐effect transistor, but no evidence of a current flow through the InAs QWRs can be found. Numerical calculations of the electron density and the device band structure confirm that a depletion zone is present in the AlAs layer close to the cleaved edge and the InAs QWR seems electrically isolated from the AlAs 2DEG leads. Possible solutions could be an additional Schottky gate contact on the CEO side or selective doping inside the CEO barrier. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Three‐dimensionally structured silicon as a substrate for the MOVPE growth of GaN nanoLEDs
Authors: Fündling Sönke , Li Shunfeng , Sökmen Ünsal , Merzsch Stephan , Hinze Peter , Weimann Thomas , Jahn Uwe , Trampert Achim , Riechert Henning , Peiner Erwin , Wehmann Hergo‐Heinrich , Waag Andreas
Published: March 2009

Three‐dimensionally patterned Si(111) substrates are used to grow GaN based heterostructures by metalorganic vapour phase epitaxy, with the goal of fabricating well controlled, defect reduced GaN‐based nanoLEDs. In contrast to other approaches to achieve GaN nanorods, we employed silicon substrates with deep etched nanopillars to control the GaN nanorods growth by varying the size and distance of the Si pillars. The small footprint of GaN nanorods grown on Si pillars minimise the influence of the lattice mismatched substrate and improve the material quality. For the Si pillars an inductively coupled plasma dry‐etching process at cryogenic temperature has been developed. An InGaN/GaN multi quantum well (MQW) structure has been incorporated into the GaN nanorods. We found GaN nanostructures grown on top of the silicon pillars with a pyramidal shape. This shape results from a competitive growth on different facets as well as from surface diffusion of the growth species. Spatially resolved optical properties of the structures are analysed by cathodoluminescence. Strongly spatial‐dependent MQW emission spectra indicate the growth rate differences on top of the rods. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nitride‐based quantum structures and devices on modified GaN substrates
Authors: Perlin Piotr , Franssen Gijs , Szeszko Justyna , Czernecki R. , Targowski Grzegorz , Kryśko Marcin , Grzanka Szymon , Nowak Grzegorz , Litwin‐Staszewska Elżbieta , Piotrzkowski Ryszard , Leszczyński Mike , Łucznik Bolek , Grzegory Izabella , Jakieła Rafał , Albrecht Martin , Suski Tadek
Published: March 2009

We have studied the properties of InGaN layers and quantum wells grown on gallium nitride substrates with intentional surface misorientation with respect to its crystalline c‐axis. Misorientation varied in the range from 0 up to 2 degree. The indium content was changed by using the different growth temperature (between 750 °C and 820 °C) during metalorganic vapor phase epitaxy. With increasing misorientation angle the average indium content decreased significantly. This effect was accompanied by the strong increase of the emission line bandwidth suggesting more pronounced indium segregation. The results of cathodoluminescence measurements show that these effects correspond to different number of atomic steps/terraces existing on the surface of gallium nitride substrate. Very interesting result is also demonstrated concerning p‐type GaN layers. With increasing misorientation, the free hole density drastically increases above 1018 cm–3. This improvement in p‐type doping is not related to the increased Mg concentration but to the reduction in the compensating donor density. Using this advantage we demonstrate nitride light emitters with improved electrical properties. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and photoluminescence studies of porous silicon formed in ferric ion containing stain etchants
Authors: Dudley Margaret E. , Kolasinski Kurt W.
Published: March 2009

Stain etching of silicon in aqueous solutions composed of FeCl3 + HF + concentrated (HClO4 or H2SO4) leads to highly luminescent porous Si with a unique dual layer structure. The upper layer (∼3 μm thick) exhibits bluer luminescence (peaked at 560–590 nm) and a porosity in excess of 84%. The lower layer exhibits redder luminescence (peaked at 630–645 nm) and a lower porosity. Both layers are crystalline and are composed predominantly of uniform micropores. Because of the substantially higher porosity of the upper layer, this layer is highly susceptible to cracking and exfoliation. Critical point drying greatly reduces cracking and exfoliation but does not eliminate cracking completely. Brushing easily removes the upper layer while leaving the lower layer intact and the removed material remains photoluminescent. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of endothelial cells on pillar‐covered silicon
Authors: Zawislak Jennifer D. , Kolasinski Kurt W. , Helmke Brian P.
Published: March 2009

Bovine aortic endothelial cells were grown on nanostructured substrates consisting of pillars with height 10 μm, pitch 6 μm, and tip diameter 0.15 μm. Cells cultured on a pillar‐covered substrate were more successful than those cultured on flat silicon wafers; however, they developed more slowly than cells cultured on glass coverslips. Specifically, focal contact maturation and matrix fibrillogenesis were inhibited. In subconfluent layers, pillars are found to penetrate deeply into both the cell cytoplasm and nucleus, suggesting that cells relaxed mechanically around the 3D topography. In confluent monolayers, actin stress fiber and VE‐cadherin distributions were indistinguishable from those in confluent monolayers on coverslips. The pillars were no longer detectable because the cells have pulled themselves up such that in the confluent layer they rest atop the pillars. Inhibition of myosin IIA with blebbistatin caused cells in a confluent layer to relax around the pillars. Thus, myosin‐mediated internal tension was required for monolayer stabilization above the pillars, suggesting that active tension among adjacent endothelial cells in a monolayer dominates mechanotransmission. Time (duration of culturing) rather than cell density appears to be a critical variable that allows for the transition from a subconfluent to a confluent layer. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Small molecule detection by reflective interferometric Fourier transform spectroscopy (RIFTS)
Authors: Pacholski Claudia , Perelman Loren A. , VanNieuwenhze Michael S. , Sailor Michael J.
Published: March 2009

A new method for the compensation of matrix effects in biosensing experiments referred to as reflective interferometric Fourier transform spectroscopy (RIFTS) has been developed recently [1]. It employs a porous silicon sensor comprised of two porous silicon layers stacked one on top of the other. The structure has a complicated reflectivity spectrum that can be resolved by FFT analysis leading to three distinctive peaks which are assigned to the layers in the porous silicon structur. If the double layer is appropriately designed, the bottom layer can act as a reference channel. In this paper the specific sensing of small molecules using RIFTS is demonstrated for the first time. Ac‐L‐Lys‐D‐Ala‐D‐Ala has been immobilized to the sensor surface representing the capture probe and vancomycin was used as target analyte. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel applications of silicon and porous silicon based EISCAP biosensors
Authors: Mathew Arun , Pandian Ganesh , Bhattacharya Enakshi , Chadha Anju
Published: March 2009

We report the fabrication of potentiometric electrolyte‐insulator capacitor (EISCAP) biosensors based on silicon and porous silicon (PS) substrates with oxide and stacked oxide‐nitride dielectrics. These biosensors have been calibrated for the detection and estimation of bioanalytes like tributyrin and urea, based on enzymatic reactions and have a linear detection range from 0.1 mM to 20 mM of the bioanalyte concentration. These improved sensitivity EISCAP sensors were used for the estimation of the total acid content in rancid butter, estimation of enzyme (Lipase) activity and to estimate total triglyceride levels in blood serum. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic characterization of Cu56Ga28Mn16 microwires
Authors: García C. , Prida V. M. , Vega V. , Llamazares J. L. Sánchez , Suñol J. J. , Escoda Ll. , Sánchez M. L. , Ribot J. , Hernando B.
Published: March 2009

The phase constitution, morphology and magnetic properties were investigated in glass‐coated microwires of the Cu–Ga–Mn ternary system produced by the Taylor–Ulitovsky method. The composition determined by energy dispersive X‐ray EDS microanalysis was Cu56Ga28Mn16. Samples were studied in the as‐cast state and after annealing at 100 °C during 30 minutes. The low‐field temperature dependence of magnetization showed the co‐existence of two ferromagnetic phases in both, as‐cast and annealed samples that persisted after annealing. The Curie temperature of major phase is 125 K, while for the second phase is above room temperature. Hysteresis loops measured at 50 K and 350 K, underlined the ferromagnetic character of both phases, while coercive field decreases with annealing more at low temperature than at 350 K [as‐cast wire: HC = 387 Oe (50 K) and 40 Oe (350 K); annealed wire: HC = 225 Oe (50 K) and 35 Oe (350 K)]. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐field non‐resonant microwave absorption in glass‐coated Co‐rich microwires
Authors: Valenzuela Raul , Montiel Herlinda , Alvarez Guillermo , Zamorano Rafael
Published: March 2009

A study of low‐field non‐resonant microwave absorption (LFA) at 9.8 GHz, on as‐cast amorphous Co‐rich CoFeBSi microwires under different measuring geometries is presented. Results confirm that LFA is associated with the magnetization processes from the unmagnetized state (HDC = 0) to the saturated condition, in many aspects similar to Giant Magnetoimpedance (GMI), and clearly different from ferromagnetic resonance (FMR). LFA signal showed large variations in its maximum–minimum separation as a function of the measuring geometry, which is interpreted in terms of the total anisotropy in the process. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)