bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioelectrochemical Systems: An Outlook for Practical Applications
Authors: Sleutels Tom H. J. A. , Ter Heijne Annemiek , Buisman Cees J. N. , Hamelers Hubertus V. M.
Published: June 2012

Bioelectrochemical systems (BESs) hold great promise for sustainable production of energy and chemicals. This review addresses the factors that are essential for practical application of BESs. First, we compare benefits (value of products and cleaning of wastewater) with costs (capital and operational costs). Based on this, we analyze the maximum internal resistance (in mΩ m2) and current density that is required to make microbial fuel cells (MFCs) and hydrogen‐producing microbial electrolysis cells (MECs) cost effective. We compare these maximum resistances to reported internal resistances and current densities with special focus on cathodic resistances. Whereas the current densities of MFCs still need to be increased considerably (i.e., internal resistance needs to be decreased), MECs are closer to application as their current densities can be increased by increasing the applied voltage. For MFCs, the production of high‐value products in combination with electricity production and wastewater treatment is a promising route.
Enzymatic versus Microbial Bio‐Catalyzed Electrodes in Bio‐Electrochemical Systems
Authors: Lapinsonnière Laure , Picot Matthieu , Barrière Frédéric
Published: June 2012

Catalyses of electrode reactions by oxidoreductases or living electroactive bacteria are compared and recent advances reviewed. The relation between the biological and nevertheless inert nature of enzymes and the living machinery of electroactive microbes is discussed. The way these biocatalysts may be electrically contacted to anodes or cathodes is considered with a focus on their immobilization at electrodes and on the issue of time stability of these assemblies. Recent improvements in power output of biofuel cells are reviewed together with applications that have appeared in the literature. This account also reviews new approaches for combining enzymes and living microbes in bioelectrochemical systems such as reproducing microbial metabolisms with enzyme cascades and expressing oxidoreductases on genetically engineered microbes. Finally, the use of surface chemistry for studying the microbe–electrode interface and bioelectrodes with cell organelles, such as mitochondria, or with higher organisms, such as yeasts, are discussed. Some perspectives for future research to extend this field are offered as conclusions.
Immunoextraction of zinc proteins from human plasma using chicken yolk antibodies immobilized onto paramagnetic particles and their electrophoretic analysis
Authors: Krizkova Sona , Ryvolova Marketa , Hynek David , Eckschlager Tomas , Hodek Petr , Masarik Michal , Adam Vojtech , Kizek Rene
Published: June 2012

Zinc(II) as the only transition metal lacking redox activity is an essential part of approximately 10% proteins as a cofactor of these proteins. Considering the fact that there are numerous zinc(II) containing proteins, proteomics and metallomics studies aimed on them require accurate methods for preparation of real biological samples prior to their subsequent analysis using 2DE and MS. For this purpose, we suggested a new method based on chicken anti‐zinc antibodies and magnetizable particles. Antibodies were covalently immobilized to the surface of paramagnetic beads activated with tosyl group. Binding of the antibody to the beads was confirmed by secondary anti‐chicken antibody conjugated with horseradish peroxidase. The immunoextraction conditions, such as concentration of the beads (6–18 μg/mL of the sample), time of immunoextraction (6–34 min), pH and composition of the elution buffer, and time of extraction (48–300 s) were optimized. Subsequently, zinc proteins were extracted from human plasma and total concentration of zinc was monitored by electrochemical detection in the extracts. Under optimal conditions it was possible to monitor the proteins and zinc removal from the sample by chip CE, SDS‐PAGE, and indirectly using electrochemistry.
A new species of Dianthus L. (Caryophyllaceae) from the West Sayan, Altai‐Sayan Mountains, Russia
Authors: Shaulo Dmitriy N. , Erst Andrey S.
Published: June 2012

A new species Dianthus mainensis (sect. Chinenses), which is endemic to the West Sayan is described and illustrated. The species is most close to D. versicolor but differs from the latter in a number of characters (e.g., leaf and stem indumentum; shape and pubescence of epicalyx scales; petal color). Similarly to the other members of this group, D. mainensis is an obligate petrophyte and grows on outcrops of carbonate rocks. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zur numerischen Modellierung von Vollverdrängungsbohrpfählen
Authors: Grabe Jürgen , Pucker Tim
Published: June 2012

Es werden numerische Simulationen zum Bohren von Vollverdrängungsbohrpfählen durchgeführt. Die verwendete gekoppelte Euler‐Lagrange‐Methode ermöglicht die Simulation großer Verformungen. Die Vorteile der Methode werden herausgestellt und deren Anwendbarkeit auf das komplexe Randwertproblem wird gezeigt. Es werden die Drehzahl bei konstanter Vorschubgeschwindigkeit und die Geometrie des Bohrwerkzeugs variiert, um deren Einfluss auf die Anpresskraft und das Drehmoment des Bohrwerkzeugs zu untersuchen. Weiterhin wird die Beeinflussung des Bodens im Nahbereich um den Pfahl die Spannungsänderungen in diesem Bereich ermittelt.

Numerical modeling of full displacement piles

The installation process of full displacement piles is simulated numerically using a three dimensional model. The coupled Eulerian‐Lagrangian method is applied, that makes the simulation of geotechnical problems with large deformations possible. The crowd force and the torque are carried out during the simulation to investigate the influences of the installation technique and the geometry of the drilling tool. The rotational speed is varied at constant penetration velocity. The influences on the soil surrounding the pile are determined investigating the stress changes in this area.
Versuche zum Abriebverhalten von Gesteinen bei hydraulischen Einwirkungen
Authors: Heibaum Michael , Warnecke Wilfried
Published: June 2012

In der Wechselwirkung von Locker‐ und Festgestein untereinander und mit anderen Werkstoffen bei Transport‐, Lade‐ und Lösevorgängen ist der Abrieb als Teil der generellen Degradation ein wichtiger Parameter. Zur Untersuchung des Abriebs bei hydraulischen Einwirkungen wurden mögliche Versuche verglichen und Parameterstudien durchgeführt. Dabei wurden der Abrieb von Lockergestein aktiv als Reibladung und passiv z. B. bei Geschiebetransport betrachtet sowie wesentliche Einflussparameter ermittelt. Für die Simulation des hydraulisch induzierten Abriebs steht mit dem Micro‐Deval‐Versuch ein geeignetes Verfahren zur Verfügung.

Investigations on the abrasion behavior of soil from hydraulic impacts

To assess the interaction of soil and rock between each other and versus other materials during transport, loading and quarrying, abrasion as one part of general degradation is an important parameter. To investigate abrasion from hydraulic effects, appropriate tests are compared and parametric studies have been performed. Both, active abrasion of soil as abradant and passive abrasion e.g. due to bedload transport are considered to work out relevant influencing factors. To simulate hydraulically induced abrasion, the Micro‐Deval‐Test has proven its suitability.
Improved prediction of Alzheimer's disease with longitudinal white matter/gray matter contrast changes
Authors: Grydeland Håkon , Westlye Lars T. , Walhovd Kristine B. , Fjell Anders M.
Published: June 2012

Brain morphometry measures derived from magnetic resonance imaging (MRI) are important biomarkers for Alzheimer's disease (AD). The objective of the present study was to test whether we could improve morphometry‐based detection and prediction of disease state by use of white matter/gray matter (WM/GM) signal intensity contrast obtained from conventional MRI scans. We hypothesized that including WM/GM contrast change along with measures of atrophy in the entorhinal cortex and the hippocampi would yield better classification of AD patients, and more accurate prediction of early disease progression. T1‐weighted MRI scans from two sessions approximately 2 years apart from 78 participants with AD (Clinical Dementia Rating (CDR) = 0.5–2) and 71 age‐matched controls were used to calculate annual change rates. Results showed that WM/GM contrast decay was larger in AD compared with controls in the medial temporal lobes. For the discrimination between AD and controls, entorhinal WM/GM contrast decay contributed significantly when included together with decrease in entorhinal cortical thickness and hippocampal volume, and increased the area under the curve to 0.79 compared with 0.75 when using the two morphometric variables only. Independent effects of WM/GM contrast decay and improved classification were also observed for the CDR‐based subgroups, including participants converting from either a non‐AD status to very mild AD, or from very mild to mild AD. Thus, WM/GM contrast decay increased diagnostic accuracy beyond what was obtained by well‐validated morphometric measures alone. The findings suggest that signal intensity properties constitute a sensitive biomarker for cerebral degenration in AD. Hum Brain Mapp 34:2775–2785, 2013. © 2012 Wiley Periodicals, Inc.
Primary visual response (M100) delays in adolescents with FASD as measured with MEG
Authors: Coffman Brian A. , Kodituwakku Piyadasa , Kodituwakku Elizabeth L. , Romero Lucinda , Sharadamma Nirupama Muniswamy , Stone David , Stephen Julia M.
Published: June 2012

Fetal alcohol spectrum disorders (FASD) are debilitating, with effects of prenatal alcohol exposure persisting into adolescence and adulthood. Complete characterization of FASD is crucial for the development of diagnostic tools and intervention techniques to decrease the high cost to individual families and society of this disorder. In this experiment, we investigated visual system deficits in adolescents (12–21 years) diagnosed with an FASD by measuring the latency of patients' primary visual M100 responses using MEG. We hypothesized that patients with FASD would demonstrate delayed primary visual responses compared to controls. M100 latencies were assessed both for FASD patients and age‐matched healthy controls for stimuli presented at the fovea (central stimulus) and at the periphery (peripheral stimuli; left or right of the central stimulus) in a saccade task requiring participants to direct their attention and gaze to these stimuli. Source modeling was performed on visual responses to the central and peripheral stimuli and the latency of the first prominent peak (M100) in the occipital source timecourse was identified. The peak latency of the M100 responses were delayed in FASD patients for both stimulus types (central and peripheral), but the difference in latency of primary visual responses to central vs. peripheral stimuli was significant only in FASD patients, indicating that, while FASD patients' visual systems are impaired in general, this impairment is more pronounced in the periphery. These results suggest that basic sensory deficits in this population may contribute to sensorimotor integration deficits described previously in this disorder. Hum Brain Mapp 34:2852–2862, 2013. © 2012 Wiley Periodicals, Inc.
Indigo and Tyrian Purple – From Ancient Natural Dyes to Modern Organic Semiconductors
Authors: Głowacki Eric Daniel , Voss Gundula , Leonat Lucia , Irimia‐Vladu Mihai , Bauer Siegfried , Sariciftci Niyazi Serdar
Published: June 2012

We describe the history of indigo dye and its derivative Tyrian purple, from their roles in the ancient world to recent research showing the semiconducting properties of indigoids. Indigoids are natural dyes that have been produced for centuries, and indigo is currently the most produced dye worldwide. Herein we review the history of these materials, their chemistry and physical properties, and their semiconducting characteristics in the solid state. Due to hydrogen bonding and π‐stacking, indigo and Tyrian purple form highly‐ordered crystalline thin films. Such films have been used to fabricate high‐performance organic field‐effect transistors with ambipolar charge transport, as well as complementary‐like circuits. Mobility values were found to be in the range of 10−2–0.4 cm2/Vs. With performance on par with the best available organic semiconductors, indigoids demonstrate the potential of sustainable electronics based on biodegradable and biocompatible materials.
Integrating Existentialism and Super's Life‐Span, Life‐Space Approach
Authors: Sterner William R.
Published: June 2012

As workers face a changing and ever‐complex employment landscape, traditional career theories and approaches may not be sufficient in meeting career challenges. Calls for integrated career theories have emerged as more people seek meaning and purpose in their lives and careers. This article proposes a career counseling option that integrates existentialism and Super's (1990) life‐span, life‐space approach to establish a foundation for a broader approach to career development that views clients holistically by exploring life and career meaning and purpose from a developmental perspective. A case example and interventions are provided to demonstrate practical application and a contextual framework, along with implications for counselors.
A Longitudinal Study of the Developmental Trajectories of Parental Attachment and Career Maturity of South Korean Adolescents
Authors: Choi Sumi , Hutchison Brian , Lemberger Matthew E. , Pope Mark
Published: June 2012

This study tested the developmental trajectories of career maturity (CM) and parental attachment (PA), the longitudinal influence of both, and gender as a moderator. Findings showed developmental progressions in adolescents’ PA and CM over 4 years. The change in PA was positively related to the developmental change in CM. For gender, there was a statistically significant difference in the initial status of CM and PA but no significant difference in developmental change. This study verified the longitudinal influence of PA on CM and showed that the cross‐sectional effect of predictors on CM needs to be distinguished from the longitudinal effect in future studies.
Trinal Decompositions of Steiner Triple Systems into Triangles
Authors: Lindner Charles C. , Meszka Mariusz , Rosa Alexander
Published: June 2012

It is well known that when or , there exists a Steiner triple system (STS) of order n decomposable into triangles (three pairwise intersecting triples whose intersection is empty). A triangle in an STS determines naturally two more triples: the triple of “vertices” , and the triple of “midpoints” . The number of these triples in both cases, that of “vertex” triples (inner) or that of “midpoint triples” (outer), equals one‐third of the number of triples in the STS. In this paper, we consider a new problem of trinal decompositions of an STS into triangles. In this problem, one asks for three distinct decompositions of an STS of order n into triangles such that the union of the three collections of inner triples (outer triples, respectively) from the three decompositions form the set of triples of an STS of the same order. These decompositions are called trinal inner and trinal outer decompositions, respectively. We settle the existence question for trinal inner decompositions completely, and for trinal outer decompositions with two possible exceptions.
PEASANT IDENTITY: CONTRIBUTIONS TOWARDS A RURAL PSYCHOLOGY FROM AN ARGENTINEAN CASE STUDY
Authors: Landini Fernando
Published: June 2012

Within the field of psychology, little attention has been paid to studying the identity of rural people, in particular the peasantry. To explore this issue, a case study was undertaken in a community located in Argentina. The research identified three different dimensions of peasants’ identity. The first one, positive identity, is based on peasants’ view of themselves as hardworking people well versed in rural work. The second dimension, the pragmatic identity, is one that encompasses peasants’ view of themselves as poor and in need of assistance, which in turn legitimizes efforts to obtain public assistance. Finally, a third dimension, of scant quantitative importance, revealed a negative identity at its core. Furthermore, it's worth mentioning that different dimensions of their identity were activated depending on the particular context within which they were set and favored the development of either passive or active positioning on the part of the peasants. © 2012 Wiley Periodicals, Inc.
DUAL MINORITY STRESS AND ASIAN AMERICAN GAY MEN'S PSYCHOLOGICAL DISTRESS
Authors: Chen and Georgiana Shick Tryon Yung‐Chi
Published: June 2012

The present study investigated the direct and additive effects of racial minority stress and sexual minority stress on the psychological well‐being among a community sample of 139 Asian American gay men. Self‐esteem was tested to see whether it moderated or mediated the effects of perceived dual minority stress on psychological distress. Results revealed that sexual minority stress predicted self‐esteem and both were predictors of psychological distress. Racial minority stress did not predict psychological distress. Contrary to the minority stress model existing in the current literature, the added disadvantages of racial/ethnic minority status did not increase Asian American gay men's psychological distress. Self‐esteem did not mediate or moderate the relationships between minority stresses and psychological distress. These findings highlight the robust effects of stresses related to one'es homosexuality on psychological well‐being and suggest that self‐esteem may not always protect against multiple discriminations for Asian American gay men. © 2012 Wiley Periodicals, Inc.
CHILD DISRUPTIVE BEHAVIOR AND PARENTING EFFICACY: A COMPARISON OF THE EFFECTS OF TWO MODELS OF INSIGHTS
Authors: O'Connor Erin , Rodriguez Eileen , Cappella Elise , Morris Jordan , McClowry Sandee
Published: June 2012

In this article, we investigate the effectiveness of INSIGHTS into Children's Temperament (INSIGHTS), a temperament‐based preventive intervention, in reducing the disruptive behavior problems of young children from low‐income, urban families. Results indicate that children enrolled in INSIGHTS evidenced a decrease in disruptive behavior problems over the course of the intervention, with children with high maintenance temperaments evidencing the most rapid rates of decline. In addition, children in a collaborative version of the program with joint parent and teacher sessions demonstrated more rapid decreases in disruptive behavior than children in a parallel version with separate parent and teacher sessions. Furthermore, high maintenance children in the collaborative intervention evidenced lower levels of disruptive behaviors at the end of the intervention than their peers in the parallel version. Increases in parenting efficacy appeared to be the mechanism through which INSIGHTS reduced child disruptive behavior. © 2012 Wiley Periodicals, Inc.
DEVELOPMENT AND VALIDATION OF A PSYCHOLOGICAL SENSE OF LGBT COMMUNITY SCALE
Authors: Lin Yen‐jui , Israel Tania
Published: June 2012

The focus of this study was the development and validation of a Psychological Sense of LGBT Community Scale (PSOC‐LGBT), designed to assess the degree to which self‐identified lesbian, gay, bisexual, and transgender (LGBT) persons report feelings of belonging to and being able to depend on their local LGBT community, as well as the degree to which they believe an LGBT community exists in their local area. The scale is a modification of an existing Psychological Sense of Community Scale (PSOCS) that was designed for gay and bisexual men (Proescholdbell et al., 2005). A total of 356 participants completed either an Internet‐based or a paper survey. Exploratory factor analysis, internal consistency, and validity coefficients supported the use and continued development of the modified instrument. Implications for future research and application are discussed. © 2012 Wiley Periodicals, Inc.
REDUCING ALCOHOL USE IN YOUTH AGED 12–17 YEARS USING THE STRATEGIC PREVENTION FRAMEWORK
Authors: Eddy Jennifer J. , Gideonsen Mark D. , McClaflin Richard R. , O'Halloran Peggy , Peardon Francie A. , Radcliffe Pamela L. , Masters Lynnette A.
Published: June 2012

Although evidence‐based interventions to reduce underage drinking have been identified, dissemination into ‘real‐world’ communities remains challenging. The purpose of this community‐based translational research is to test SAMHSA's Strategic Prevention Framework (SPF) as a model for such dissemination and evaluate its effect on alcohol use by youth aged 12–17. From 2001–2009 in Eau Claire, Wisconsin we used the SPF to assess community needs and implement a comprehensive strategy of evidence‐based programs targeting youth, parents and the community. Over this time, youth alcohol measures from middle and high school surveys showed an 8.6% decline in past‐month alcohol use (p<.05) and a 20.5% decline in ease of obtaining alcohol (p<.05). From 2004 to 2009 there was a 5.8% decrease in binge alcohol use (p<.05) and a 12.0% increase in perceived parental disapproval of alcohol use (p<.05). Based on our findings, the SPF is a promising model for communities seeking to reduce underage drinking. © 2012 Wiley Periodicals, Inc.
Taurine chloramine induces apoptosis in human osteosarcoma cell lines
Authors: Pilz Magdalena , Holinka Johannes , Vavken Patrick , Marian Brigitte , Krepler Petra
Published: June 2012

Although combination of surgery with chemotherapy has noticeably improved the survival rate of osteosarcoma patients, the application of anticancer drugs is still associated with significant adverse reactions, for instance acquisition of drug‐resistant phenotypes, necessitating the development of new chemotherapeutical agents. Therefore, the aim of this study was to research, if taurine chloramine (NCT) induces apoptosis in the osteosarcoma cell lines HOS, MG‐63, and SAOS‐2. Proliferation of osteosarcoma cells was detected with the “EZ4U Cell Proliferation and Cyotoxicity Assay” showing a time‐ and dose‐dependent cytotoxic effect of NCT on these cell lines. After 3 h of incubation all cell lines showed significantly less cells at 5.5 mM NCT solutions, after 6 h at concentrations of 1.1 and 2.2 mM. Acridine‐orange fluorescence nuclear staining showed characteristic features of apoptosis. DNA fragmentation was detected via ELISA, showing significant results for HOS and MG‐63 after 6 h at an NCT concentration of 3.3 mM. Results of JC‐1 mitochondrial FACS analysis presented a significant increase in apoptotic cells after 6 h at 3.3 mM for the tested cell lines. Summarized, the results of this study indicate that NCT is a promising agent in osteosarcoma therapy. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:2046–2051, 2012
Preparative purification of peoniflorin and albiflorin from peony rhizome using macroporous resin and medium‐pressure liquid chromatography
Authors: Wang Rong , Peng Xiaoguo , Wang Liming , Tan Beibei , Liu Jiangyun , Feng Yulin , Yang Shilin
Published: June 2012

Peoniflorin (PF) and albiflorin (AF) are two principal components of Paeonia species, which exhibit various biological activities such as improvement of blood circulation and immunoregulating function. To further utilization of waste parts of peony plants, an efficient method for preparative purification of these two ingredients from white peony rhizome was developed based on macroporous resin (MAR) and medium‐pressure liquid chromatography (MPLC). The separation characteristics of nine typical MARs were investigated by static adsorption/desorption experiments, and LX38 was revealed as optimal one. Further static experiments with LX38 resin indicated that the adsorbents fitted well to the pseudo‐second‐order kinetics model and both Langmuir and Freundlich isotherm models. Based on the optimal process parameters, a large‐scale preparation was successfully applied. After one run treatment with LX38, the contents of PF and AF were increased 15‐fold to 24.5 and 16.8% in the refined extract, respectively. Both purified compounds were obtained from refined extract by reversed‐phase MPLC at second‐stage separation. The process developed is better because of its low cost, high efficiency, and procedural simplicity making it a potential approach for large‐scale production of PF and AF for their further applications in functional foods and pharmaceuticals.
A method for the identification and quantitation of hydraulic fluid contamination of turbine engine oils by gas chromatography–chemical ionisation mass spectrometry
Authors: Webster Renée L. , Evans David J. , Rawson Paul M.
Published: June 2012

The identification of aircraft hydraulic fluid contamination of turbine engine oils is difficult. Repeated field incidents of this type of cross contamination have led to the requirement to develop a method suitable for quantitation of such contamination. A gas chromatography–chemical ionisation mass spectrometry method for the determination of H‐537 hydraulic fluid contamination in turbine engine oil was developed and validated. The intraday and interday relative standard deviations of the standards were 3–7% and 5–9%, respectively. Mean recoveries of hydraulic fluid in turbine engine oil were 90–94%, and the calibration curve was linear with R2 = 0.999. Limits of detection and quantitation were 0.05% (w/w) and 0.5% (w/w), respectively. The method was successfully applied to laboratory degraded samples and field samples. Copyright © 2012 John Wiley & Sons, Ltd.
Functional Monolithic Materials for Boronate‐Affinity Chromatography via Schrock Catalyst‐Triggered Ring‐Opening Metathesis Polymerization
Authors: Bandari Rajendar , Buchmeiser Michael R.
Published: June 2012

Monolithic polymeric materials are prepared via ring‐opening metathesis copolymerization of norborn‐2‐ene with 1,4,4a,5,8,8a‐hexahydro‐1,4,5,8‐exo,endo‐dimethanonaphthalene in the presence of macro‐ and microporogens, that is, of n‐hexane and 1,2‐dichloroethane, using the Schrock catalyst Mo(N‐2,6‐(2‐Pr)2‐C6H3)(CHCMe2Ph)(OCMe3)2. Functionalization of the monolithic materials is accomplished by either terminating the living metal alkylidenes with various functional aldehydes or by post‐synthesis grafting with norborn‐5‐en‐2‐ylmethyl‐4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)benzoate. Finally, boronate‐grafted monolithic columns (100 × 3 mm i.d.) are successfully applied to the affinity chromatographic separation of cis‐diol‐based biomolecules.
Numerical solution of nonlinear three‐point boundary value problem on the positive half‐line
Authors: Niu J. , Lin Y. Z. , Zhang C. P.
Published: June 2012

In this paper, we present an efficient numerical algorithm to solve the three‐point boundary value problem on the half‐line based on the reproducing kernel theorem. Considering the boundary conditions including a limit form, a new weighted reproducing kernel space is established to overcome the difficulty. By applying reproducing property and existence of the orthogonal basis in the weighted reproducing kernel space, the approximate solution is constructed by the orthogonal projection of the exact solution. Convergence has also been discussed. We demonstrate the accuracy of the method by numerical experiments. Copyright © 2012 John Wiley & Sons, Ltd.
Some properties of solutions for a fourth‐order parabolic equation
Authors: Zhao Xiaopeng , Zhang Min , Liu Changchun
Published: June 2012

This paper is concerned with a fourth‐order parabolic equation in one spatial dimension. On the basis of Leray–Schauder's fixed point theorem, we prove the existence and uniqueness of global weak solutions. Moreover, we also consider the regularity of solution and the existence of global attractor. Copyright © 2012 John Wiley & Sons, Ltd.
Vaccination model for visceral leishmaniasis with infective immigrants
Authors: ELmojtaba Ibrahim M. , Mugisha J.Y.T. , Hashim Mohsin H.A.
Published: June 2012

In this paper, we present and analyzed a mathematical model that describes the dynamics of visceral leishmaniasis in a population with immigration of infective humans under mass vaccination strategy. Our result shows that in order for the vaccine to play a role on disease control, it must be very effective. Results also show that vaccination coverage does not have any impact on disease control when the immigration rate is small, and it does not affect the long‐term behavior when the immigration rate is high. In the case of no immigration of infective, our system has disease‐free equilibrium, and it is globally asymptotically stable when , the basic reproduction number, is less than unity. Numerical simulation shows that in the case of no immigration of infective, our system undergoes forward bifurcation when passes throw unity. Copyright © 2012 John Wiley & Sons, Ltd.
Delay decomposition approach to state estimation of neural networks with mixed time‐varying delays and Markovian jumping parameters
Authors: Lakshmanan S. , Vembarasan V. , Balasubramaniam P.
Published: June 2012

This paper investigates the state estimation of neural networks with mixed time‐varying delays and Markovian jumping parameters. By developing a delay decomposition approach, the information of the delayed plant states can be taken into full consideration. On the basis of the new Lyapunov–Krasovskii functional, some inequality techniques, stochastic stability theory and delay‐dependent stability criteria are obtained in terms of linear matrix inequalities. Finally, three numerical examples are given to illustrate the less conservative and effectiveness of our theoretical results. Copyright © 2012 John Wiley & Sons, Ltd.
Electrical stimulation of sacral dermatomes can suppress aberrant urethral reflexes in felines with chronic spinal cord injury
Authors: McCoin Jaime L. , Bhadra Narendra , Gustafson Kenneth J.
Published: June 2012

Aims

Uncoordinated reflex contractions of the external urethral sphincter (EUS) are a major component of voiding dysfunction after neurologic injury. Patterned stimulation of sacral afferent pathways can reduce abnormal EUS reflexes after acute spinal cord injury (SCI); however, effectiveness following chronic SCI is unknown.

Methods

Four adult male cats were implanted with bilateral extradural sacral root electrodes to allow bladder activation and underwent subsequent spinal transection (T10–12). Nine weeks after SCI urethral and bladder pressures were recorded with and without sacral afferent stimulation. Surface electrodes were applied to sacral and lumbar dermatomes and stimulus amplitude set below the muscle fasciculation threshold. The stimulation pattern was varied by on/off times of fixed frequency at each location.

Results

Reflexive EUS contractions were observed in all animals after chronic SCI. Patterned sacral dermatome stimulation reduced EUS reflex rate and amplitude in two of four cats. Suppression was dependent on both the stimulus location and pattern. Sacral locations and a stimulation pattern of (0.75 sec on, 0.25 sec off, 20 Hz) were effective in both responder animals.

Conclusions

Patterned sacral dermatome stimulation can reduce abnormal urethral reflexes following chronic SCI. Reflex suppression is dependent on both the stimulation location and stimulus pattern. Reduction of reflexive EUS activity after chronic SCI with this non‐destructive and non‐invasive approach may provide an advance for the treatment of detrusor‐sphincter‐dyssynergia. Neurourol. Urodynam. 32: 92–97, 2013. © 2012 Wiley Periodicals, Inc.
Active control of sloshing in containers with elastic baffle plates
Authors: Hernández Erwin , Santamarina Duarte
Published: June 2012

We consider the finite element approximations of an optimal control problem consisting in the suppression of slosh arising in fluid–structure interaction problems with free surface. The vibration of a plate in contact with an incompressible fluid is considered as state equations in the optimization problem, and distributed controls on the plate are calculated to suppress the slosh.

Locking‐free finite elements are used to discretize the plate, which is modeled by Reissner–Mindlin equations. The effect of the fluid is taken into account by means of an added mass formulation, discretized by standard piecewise linear tetrahedral finite elements, and the gravity waves on the free surface of the liquid are considered in the model. The control variable is the amplitude of a secondary force actuating on the structure.

Implementation issues are discussed, and numerical experiments are presented. Copyright © 2012 John Wiley & Sons, Ltd.
Computational nonlinear stochastic homogenization using a nonconcurrent multiscale approach for hyperelastic heterogeneous microstructures analysis
Authors: Clément A. , Soize C. , Yvonnet J.
Published: June 2012

This paper is devoted to the computational nonlinear stochastic homogenization of a hyperelastic heterogeneous microstructure using a nonconcurrent multiscale approach. The geometry of the microstructure is random. The nonconcurrent multiscale approach for micro‐macro nonlinear mechanics is extended to the stochastic case. Because the nonconcurrent multiscale approach is based on the use of a tensorial decomposition, which is then submitted to the curse of dimensionality, we perform an analysis with respect to the stochastic dimension. The technique uses a database describing the strain energy density function (potential) in both the macroscopic Cauchy green strain space and the geometrical random parameters domain. Each value of the potential is numerically computed by means of the FEM on an elementary cell whose geometry is given by the random parameters and the corresponding macroscopic strains being prescribed as boundary conditions. An interpolation scheme is finally introduced to obtain a continuous explicit form of the potential, which, by derivation, allows to evaluate the macroscopic stress and elastic tangent tensors during the macroscopic structural computations. Two numerical examples are presented. Copyright © 2012 John Wiley & Sons, Ltd.
An exact reanalysis algorithm using incremental Cholesky factorization and its application to crack growth modeling
Authors: Pais Matthew J. , Yeralan Sencer N. , Davis Timothy A. , Kim Nam H.
Published: June 2012

In this paper, an exact reanalysis algorithm based on an incremental Cholesky factorization is presented, which can solve a linear system of equations when a small portion of the coefficient matrix is modified. The efficiency of the proposed algorithm is demonstrated by modeling quasi‐static crack growth in the extended finite element method. The example presented shows that a 60% to 70% reduction in computational time is achievable by using the reanalysis approach for solving crack growth problems. It is shown that the reanalysis approach has increasing benefits as the mesh density increases. Copyright © 2012 John Wiley & Sons, Ltd.
Development of Quantitative Analytical Methods to Measure the Polymorphic Composition of CL20 (Hexanitrohexaazaisowurtzitane – HNIW) with FTIR‐NIR or FTIR‐MIR Spectroscopy using PLS Regression
Authors: Dumas Séverine , Gauvrit Jean Yves , Lanteri Pierre
Published: June 2012

CL20 (HNIW=Hexanitrohexaazaisowurtzitane), is an energetic molecule that presents four polymorphs (called alpha (α), beta (β), gamma (γ), and epsilon (ε)). Industry is focused to synthesize the ε‐form. For them, it is very important to get an analytical method to quantify the concentration of the ε‐form, which has the best energetic performance. The aim of this work is to develop a quantitative analytical method to measure the polymorphic composition of CL20 using FTIR (mid IR and near IR, MIR/NIR) spectroscopy with PLS regression.
Ion‐beam‐induced mixing in a Si/Co/Si system involving ultrathin layers: A grazing‐incidence X‐ray standing‐wave study
Authors: Roy Sumalay , Dev B. N.
Published: June 2012

Energetic ion‐beam‐induced mixing between Co and Si has been studied in a Si (∼5 nm)/Co (∼10 nm) bilayer system deposited on a Si (111) substrate for various ion fluences, ranging from 3 × 1014 ions/cm2 to 1 × 1015 ions/cm2. The amount of ion irradiation induced migration of Co atoms and the predominant direction of this migration (inward or outward) from the Co layer have been determined using combined X‐ray reflectivity (XRR) and X‐ray standing‐wave (XSW) techniques under grazing‐incidence conditions. Grazing‐incidence XSW technique is very sensitive for the detection of surface segregation, i.e., it would efficiently detect migration of Co toward the surface. However, in the present case ion‐beam‐induced migration of Co has been found to be predominantly inward, i.e., into the Si substrate. In this ultrathin layered system, grown under ultrahigh vacuum condition, Co has predominantly grown in a face centred cubic (fcc) – (111) orientation. In addition formation of cobalt silicide phases at the interfaces, even in the as‐prepared sample, is observed. Ion‐beam‐induced atomic mixing leads to enhanced growth of these silicide phases at the interfaces between Si and Co. However, even at the highest ion fluence in irradiation the (111)‐textured fcc Co is not fully consumed into formation of cobalt silicides.
Structural, electrical, and optical properties of thermally evaporated Ge–Te, Ge–Sb–Te, and Sb–Te thin films
Authors: Kumar S. , Singh D. , Sandhu S. , Thangaraj R.
Published: June 2012

Thin films of GeTe, Ge2Sb2Te5 and Sb2Te3 have been synthesized from their respective polycrystalline bulk by thermal evaporation. X‐ray diffraction study of the films confirms the amorphous nature of GeTe and Ge2Sb2Te5 films, but as‐deposited Sb2Te3 film was in the crystalline form. Structural analysis has been performed for the annealed films above their crystallization temperature by XRD, which was evaluated by temperature‐dependent sheet resistance measurements. The Sb2Te3 film, which was already crystalline, undergoes a small transition at 110 °C. For optical studies, the transmittance and the reflectance spectra were measured over the wavelength ranges 400–2500 nm using UV‐VIS‐NIR spectroscopy. The optical bandgap, reflectance and optical contrast are also presented for thermally evaporated thin films. The dc electrical conductivity of the as‐deposited films has been measured as a function of temperature below the phase‐transition temperature, and increases exponentially with temperature. The value of the activation energy, calculated from the slope of lnσ versus 1000/T, is found to decrease from one end binary GeTe to pseudobinary Ge2Sb2Te5 and then to the other end binary Sb2Te3 films. On the basis of the pre‐exponential factor, the type of conduction in these films has also been discussed in the measured temperature range.
Organic magnetoresistance and spin diffusion in organic semiconductor thin film devices
Authors: Wohlgenannt Markus
Published: June 2012

We review recent work in the field of organic spintronics, focusing on our own contributions to this field. There are two principle magnetoresistance effects that occur in organic devices. (i) Organic magnetoresistance (OMAR), which occurs in nonmagnetic organic semiconductor devices. For example, in devices made from the prototypical small molecule Alq3 OMAR reaches values of 10% or more at room temperature. (ii) Organic spin‐valve effects that occur in devices that employ ferromagnetic electrodes for spin‐polarized current injection and detection. We undertake an analysis of these two types of magnetoresistance with the goal of identifying the dominant spin‐scattering mechanism. Analysis of OMAR reveals that hyperfine coupling is the dominant spin‐coupling mechanism. Spin–orbit coupling, on the other hand, is important only in organic semiconductor materials containing heavy atoms. We explore the reasons why spin–orbit coupling is relatively unimportant in hydrocarbon materials. Next, we present a theory for spin diffusion in disordered organic semiconductors based on hyperfine coupling, taking into account a combination of incoherent carrier hopping and coherent spin precession in the random hyperfine magnetic fields. We compare our findings with experimental values for the spin‐diffusion length. Finally, we demonstrate a criterion that allows the determination whether the organic spin‐valves operate in the tunneling or injection regimes. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Static and dynamic polarizability of C540 fullerene
Authors: Calaminici Patrizia , Carmona‐Espindola Javier , Geudtner Gerald , Köster Andreas M.
Published: June 2012

State‐of‐the‐art calculations of static and dynamic polarizabilities of the giant fullerene C540 are presented. These density functional theory calculations have been performed using time‐dependent auxiliary density perturbation theory which was recently implemented in deMon2k (Carmona‐Espíndola et al., JCP 2010, 133, 084102). For the polarizability calculations the local density approximation was used in combination with all‐electron double‐zeta valence polarization basis sets. To gain insight into the trend of these properties as the fullerene size increases the obtained results for C540 are discussed with respect to those obtained for smaller fullerenes such as C60, C70, C180, and C240. All fullerene structures were fully optimized without symmetry constrains. As the cluster size increases the dynamic polarizability strongly increases with respect to the static polarizability. Our analysis shows that static and dynamic polarizabilities per atom increase significantly with fullerene size. Moreover, the increase in the dynamic polarizabilities per atom is larger than for the static ones. © 2012 Wiley Periodicals, Inc.
Atmospheric degradation mechanisms of a simulant organophosphorus pesticide isopropyl methyl methylphosphonate: A theoretical consideration
Authors: Hu Shu‐Xian , Yu Jian‐Guo , Zeng Eddy Y.
Published: June 2012

Calculations using density functional theory were performed to explore the mechanisms for atmospheric degradation of isopropyl methyl methylphosphonate (IMMP). The potential energy surface profiles for OH‐initiated reaction of IMMP were constructed, and all possible degradation channels were considered. Rate constants were further calculated using transition state theory. It was established from these calculations that H‐abstractions from alkyl groups have much lower energy barriers than substitutions of alkoxyl groups, and four possible H‐abstraction channels are competitive. Investigations into the secondary reactions under the presence of O2/NO were also performed. It is shown that O2 addition, reaction of peroxide radicals with NO to form RO radicals, and removal of ·RO are the major degradation pathways for alkyl radicals. Four selected products, CH3OP(O)(CH3)OC(O)CH3, CH3OP(O)(O)CH3, (CH3)2CHOP(O)(CH3)OH, and (CH3)2CHOP(O)(CH3)OCHO, are predicted to be the major products in this study. © 2013 Wiley Periodicals, Inc.
Estimating stacking interaction energy using atom in molecules properties: Homodimers of benzene and pyridine
Authors: Zhikol Oleg A. , Shishkin Oleg V.
Published: June 2012

An attempt is presented to infer the stacking interaction energy from the atom in molecules (AIM) properties computed in all critical points of electron density found between interacting molecules. In this study, benzene and pyridine homodimers in coaxial and parallel displaced configurations were used as model structures. We classify the structures and briefly discuss their peculiarities in the AIM theory framework. The maximum absolute error of 2 kcal/mol achieved for 300 potential energy surface point set indicates that a more sophisticated algorithm for estimating atom–atom interactions is needed still. © 2012 Wiley Periodicals, Inc.
Density functional theory study on the interaction between metalloporphyrins and NH3
Authors: Cao Zhenfeng , Chen Qibin , Lu Yunxiang , Liu Honglai , Hu Ying
Published: June 2012

The binding behaviors of eight bivalent metalloporphyrins (MPs) (MZn, Mg, Cu, Mn, Fe, Co, Ni, and Cd) with NH3 were investigated by density functional theory. For both MPs and corresponding complexes MPs‐NH3, good linear correlations are found between the partial charge on metal M and that on atom N (nitrogen of porphyrin) as well as the MN bond length. Natural population and frontier orbital analysis demonstrate that charge transfer in CoP‐NH3 is much easier and greater. As a consequence of the charge transfer and the hybridization of molecular energy levels, striking disparities of electronic properties of MPs‐NH3 are observed. Particularly, a modest linear relationship is obtained between the magnitude of charge transfer and the binding energy. The much greater Fukui functions of CoP, together with its larger binding strength, suggest that CoP is more favorable to the interaction with NH3, which might be a promising sensing material to response NH3. © 2013 Wiley Periodicals, Inc.
The detection of high‐mass aliphatics in petroleum by matrix‐assisted laser desorption/ionisation mass spectrometry
Authors: Lorente Esther , Berrueco Cesar , Herod Alan A , Millan Marcos , Kandiyoti Rafael
Published: June 2012

RATIONALE

The development of simplified procedures for isolating high‐mass alkanes present in crude oils is described. The new procedures, which bypass the sample recovery step with hot toluene in the conventional alkane‐isolation procedure, also provide an effective sample preparation route, prior to analysis by matrix‐assisted laser desorption/ionisation mass spectrometry (MALDI‐MS).

METHODS

Urea‐alkane adducts are formed by mixing sample and urea solutions on chromatographic paper or silica‐coated plates. Unreacted hydrocarbons are removed by developing the plates with chloroform. In a second development with water, adducts are broken up in situ and the liberated urea removed, leaving bands of isolated alkanes behind. For MALDI‐MS, strips of paper/plates, carrying the isolated alkanes, are fixed on metal target plates. The samples are treated with matrix (AgNO3) and analysed by MALDI‐MS.

RESULTS

The observed signal represents silver ion adducts of the isolated alkanes. Silver appears to work without much fragmentation and to generate whole silver adduct ions. Much improved MALDI‐MS detection sensitivity and a wider range of masses was observed when samples were ablated from paper/plate surfaces, than by ablation from bulk samples spread over a smooth surface – the conventional method. Chromatographic paper gave better resolution and a broader range of masses than silica‐coated plates.

CONCLUSIONS

The analytical sequences have been confirmed using standard alkanes (C20–C60) and Polywax. The proposed procedures enhanced the sensitivity and detection range of the MS analysis. The method was useful in detecting n‐alkanes to m/z 1500 (C100) and required relatively small quantities of sample and reagents. It provides a promising qualitative analysis route for the rapid isolation and reliable determination of alkanes in crude oils. Copyright © 2012 John Wiley & Sons, Ltd.