bluuebunny/crossref_metadata_2025 huggingface dataset:
How to Get Ternary Solid Solutions Fe1–xM′xO (M = Co, Ni)? A Thermodynamic Concept
Authors: Schmidt Peer
Published: May 2008

The existence ranges of ternary solid solutions Fe1–xM′xO (M = Co, Ni) have been estimated using thermodynamic modelling by CALPHAD methods: a complete series of mixed crystals Fe1–xCoxO is stable only at higher temperatures  ≥ 900 °C. Below the solid solution shows a miscibility gap due to the different redox potentials [p(O2) = f(T)] of the binary phases “FeO” and CoO. Hence CoO becomes reduced into metallic cobalt while “FeO” is oxidised into Fe3O4. The pseudo binary system FeO/NiO shows solubility ranges only at the border of the binary oxides, the phases built areα(Fe1–xNixO) (x ≤ 0.13) and α′(FeyNi1–yO) (y ≤ 0.60,  ≤ 1400 °C). Due to the broader difference of redox potentials [p(O2) = f(T)] of “FeO” and NiO a complete series of mixed crystals cannot exist. In application of the results of thermodynamic modelling the syntheses of mixed crystals Fe1–xCoxO and their characterisation by X‐ray diffraction and thermal analysis succeeds. The mixed phases crystallise in the halite structure type (space group Fm$\bar {3}$m) with a progress of the lattice constants corresponding to the Vegard rule [a(Fe1–xCoxO) = 430.0(2) pm (x = 0), 427.8(2) pm (x = 0.5), 425.0(2) pm (x = 1)].(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Mechanistic Study of Intramolecular Aldol Reactions of Dialdehydes
Authors: Duarte Filipe J. S. , Cabrita Eurico J. , Frenking Gernot , Santos A. Gil
Published: May 2008

Transition states associated with the C–C bond‐formation step in proline‐catalyzed intramolecular aldol reactions of 1,7‐dialdehydes were studied using density functional theory methods (DFT), at the B3LYP/6‐31G(d,p) level. A polarizable continuum model (PCM) was used to describe solvent effects. Two reactive channels, corresponding to the anhydrous system or to the explicit inclusion of water have been analysed. Computational data allow us to rationalize the intramolecular aldol reaction experimental outcome, validating the proposed enamine‐based mechanism, as well as to suggest the importance of water in the control of the reaction stereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemical Aptasensor for the Determination of Cocaine Incorporating Gold Nanoparticles Modification
Authors: Li Xiaoxia , Qi Honglan , Shen Lihua , Gao Qiang , Zhang Chengxiao
Published: May 2008

A novel electrochemical aptasensor incorporating a signal enhancement for the determination of cocaine was designed. Gold nanoparticles were self‐assembled onto the surface of a gold electrode through 1,6‐hexanedithiol. A bifunctional derivative of the 32‐base cocaine‐binding aptamer with a redox‐active ferrocene moiety and a thiol linker group at the termini of the strand was self‐assembled onto the surface of gold nanoparticles. The oxidation peak current is linearly related to the concentration of cocaine from 1.0 to 15.0 μM with a detection limit of 0.5 μM. It was found that the sensitivity of the aptasensor with gold nanoparticles modification was ca. 10‐fold higher than that of the aptasensor without gold nanoparticles modification. This work demonstrates that gold nanoparticles‐assembled gold electrode provides a promising platform for immobilizing aptamer and enhancing the sensitivity.
Fabrication of Tyrosinase Biosensor Based on Multiwalled Carbon Nanotubes‐Chitosan Composite and Its Application to Rapid Determination of Coliforms
Authors: Cheng Yuxiao , Liu Yajun , Huang Jingjing , Xian Yuezhong , Zhang Zhonghai , Jin Litong
Published: May 2008

A tyrosinase (Tyr) biosensor was fabricated by immobilizing Tyr on the surface of multiwalled carbon nanotubes (MWNTs)‐chitosan (Chit) composite modified glassy carbon electrode (GCE). The MWNTs‐Chit composite film provided a biocompatible platform for the Tyr to retain the bioactivity and the MWNTs possessed excellent inherent conductivity to enhance the electron transfer rate. The Tyr/MWNTs‐Chit/GCE biosensor showed high sensitivity (412 mA/M), broad linear response (1.0×10−8–2.8×10−5 M), low detection limit (5.0 nM) and good stability (remained 93% after 10 days) for determination of phenol. The biosensor was further applied to rapid detection of the coliforms, represented by Escherichia coli (E. coli) in this work. The current responses were proportional to the quantity of coliforms in the range of 104–106 cfu/mL. After 5.0 h of incubation, E. coli could be detected as low as 10 cfu/mL.
Electrochemical Immunoassay for Free Prostate Specific Antigen (f‐PSA) Using Magnetic Beads
Authors: Sarkar P. , Ghosh D. , Bhattacharyay D. , Setford S. J. , Turner A. P. F.
Published: May 2008

Prostate specific antigen (PSA) is a prominent marker for the prostate carcinoma. It is found in human blood in free (f‐PSA) and complex forms. These two forms together are called total PSA (t‐PSA). Estimation of both forms is essential to predict malignancy. In this study we report a unique and effective technique of electrochemical detection of f‐PSA using magnetic beads on a three‐electrode screen‐printed sensor. A magnetic bead enzyme linked immunosorbent assay (ELISA) was performed in a cuvette. Following the immunoassay, magnetic beads were recovered by a magnetic concentrator and transferred on the working electrode of the 3‐electrode assembly. The amperometric response, a measure of the amount of residual enzyme activity on the beads and hence the concentration of analyte in solution, was determined by addition of enzyme substrate. The device has a detection limit of <0.1 ng mL−1 f‐PSA and a linear range of 0 to 1 ng mL−1 f‐PSA.
Voltammetric and DFT Studies on Viloxazine: Analytical Application to Pharmaceuticals and Biological Fluids
Authors: Garrido E. Manuela P. J. , Garrido Jorge M. P. J. , Esteves Mário , Santos‐Silva Alice , Marques M. Paula M. , Borges Fernanda
Published: May 2008

The oxidative behavior of viloxazine was studied at a glassy carbon electrode in different buffer systems using cyclic, differential pulse and square‐wave voltammetry. The oxidation process was shown to be diffusion‐controlled and irreversible over the studied pH. The voltammetric study of the model compounds, 2‐ethoxyanisole and morpholine, associated with quantum mechanical (DFT) calculations, allowed to elucidate the oxidation mechanism of viloxazine. An analytical method was developed for the quantification of viloxazine using an acetate pH 5 buffer solution as a supporting electrolyte. A linear response was obtained in the range 7 to 45 μM, with a detection limit of 0.8 μM. Validation parameters such as sensitivity, precision and accuracy were evaluated. The proposed method was successfully applied to the determination of viloxazine in pharmaceutical formulations and in human serum. The results were statistically compared with those obtained through an established high‐performance liquid chromatography technique, no significant differences having been found between the two methods.
A Solid State Polymer‐Coated Electrode Containing a Chiral Crown Ether Derivative for Enantioselective Detection of Phenylglycine Methyl Ester Isomer
Authors: Piao Ming‐Hua , Hwang Jaeyoung , Won Mi‐Sook , Hyun Myung Ho , Shim Yoon‐Bo
Published: May 2008

All solid‐state enantioselective electrode (ASESE) based on a newly synthesized chiral crown ether derivative ((R)‐(−)‐(3,3′‐diphenyl‐1,1′‐binaphthyl)‐23‐crown‐6 incorporating 1,4‐dimethoxybenzene) was prepared and characterized by potentiometry. The ASESE clearly showed enantiomer discrimination for methyl esters of alanine, leucine, valine, phenylalanine, and phenylglycine, where the enantioselectivity for phenylglycine methyl ester was the highest (KR,S=8.5±7.1%). Experimental parameters of ASESE for the analysis of (R)‐(−)‐phenylglycine methyl ester were optimized. The optimized ASESE showed a slope of 55.3±0.2 mV/dec for (R)‐(−)‐phenylglycine methyl ester in the concentration range of 1.0×10−5–1.0×10−2 M and the detection limit was 9.0×10−6 M. The ASESE showed good selectivity for (R)‐(−)‐phenylglycine methyl ester against inorganic cations and various amino acid methyl esters. The concentration of (R)‐(−)‐phenylglycine methyl ester was determined in the mixture of (R)‐(−) and (S)‐(+)‐phenylglycine methyl ester, which ratios varied from 2 : 1 to 1 : 9. The lifespan of the electrode was alleged to be 30 days.
Poly(neutral red): Electrosynthesis, Characterization, and Application as a Redox Mediator
Authors: Pauliukaite Rasa , Brett Christopher M. A.
Published: May 2008

The synthesis by electropolymerization, the characterization, and applications of poly(neutral red) (PNR), including as a redox mediator, are reviewed. PNR's high electrical conductivity and its redox characteristics have led to special applications of the polymer, and it has been used for the development of electrochemical and optical sensors. Moreover, the attractive properties of PNR allow it to be applied in the development of electrochemical biosensors. Future perspectives are indicated.
The Mediated Electrochemical Method for Rapid Fermentation Ability Assessment
Authors: Zhao Jinsheng , Wang Zhong , Fu Chonggang , Wang Min , He Qingpeng
Published: May 2008

The mediated electrochemical method characterized by the combinational utilization of two double mediator systems was proposed to assess the fermentation efficiency of three yeasts. The mediator systems selected were the menadione/ferricyanide system and the 2,6‐dichlorophenolindophenol (DCPIP)/ferricyanide system. Both the electrochemical responses and succinate dehydrogenase assay suggested that the menadione/ferricyanide system made the yeasts switch to anaerobic respiration and, the DCPIP/ferricyanide system let the yeasts remain in theirs fermentative mode. The ethanol yields (g ethanol/g glucose) and the RD/RM (RD and RM refer to the electrochemical response from the menadione/ferricyanide system and the DCPIP/ferricyanide system, respectively) values are 0.47 and 0.38, 0.24 and 0.75, 0.23 and 0.81, respectively, for Saccharomyces cerevisiae, Pachysolen tannophilus and Pichia stipitis. The results showed that there was a negative correlation between the ethanol yields and the RD/RM values of the three yeasts, which showed the feasibility of the mediated electrochemical method in rapid fermentation ability assay.
Novel Studies about the Electrooxidation of a Deoxynivalenol (DON) Mycotoxin Reduction Product Adsorbed on Glassy Carbon and Carbon Paste Electrodes
Authors: Molina Patricia Gabriela , Zón María Alicia , Fernández Héctor
Published: May 2008

A novel and fast square‐wave adsorptive anodic stripping voltammetric procedure on glassy carbon and carbon paste electrodes is described for the indirect trace quantitation of deoxynivalenol (DON) mycotoxin that frequently contaminates soya and foodstuff. The in situ homogeneous reduction of the toxin by product/s of dissolved oxygen electroreduction in pH 8 buffer solution makes the quantitation of DON possible through a simple electroanalytical technique. Moreover, its potential use for the analysis of real samples was demonstrated using a soya flour sample spiked with DON without previous separating procedures. The DON detection limits were 3.6 and about 6 ppb from standard solutions and soya flour matrix, respectively.
Arsenite Determination in Phosphate Media at Electroaggregated Gold Nanoparticle Deposits
Authors: Rassaei Liza , Sillanpää Mika , French Robert W. , Compton Richard G. , Marken Frank
Published: May 2008

Compared to bulk gold, highly reactive mesoporous gold film deposits are prepared on a boron‐doped diamond electrode surface. An electroaggregation process causing 5 nm diameter gold nanoparticles to deposit cathodically from aqueous solution is implemented to control the amount of mesoporous gold at the electrode surface. The resulting electrode surface is characterized by electron microscopy and by cyclic voltammetry.
Use of collision shear walls to minimize seismic separation and to protect adjacent buildings from collapse due to earthquake‐induced pounding
Authors: Anagnostopoulos S. A. , Karamaneas C. E.
Published: May 2008

The use of collision shear walls (bumper‐type), acting transversely to the side subject to pounding, as a measure to minimize damage of reinforced concrete buildings in contact, is investigated using 5‐story building models. The buildings were designed according to the Greek anti‐seismic and reinforced concrete design codes. Owing to story height differences potential pounding in case of an earthquake will occur between floor slabs, a case specifically chosen because this is when pounding can turn out to be catastrophic. The investigation is carried out using nonlinear dynamic analyses for a real earthquake motion and also a simplified solution for a triangular dynamic force of short duration, comparable to the forces caused by pounding. For such analyses, nonlinear, prismatic beam–column elements are used and the effects of pounding are expressed in terms of changes in rotational ductility factors of the building elements. The local effects of pounding on the collision shear walls are investigated using a detailed nonlinear finite element model of the shear walls and results are expressed in terms of induced stresses. It is found that pounding will cause instantaneous acceleration pulses in the colliding buildings and will somewhat increase ductility demands in the members of the top floor, but all within tolerable limits. At the same time the collision walls will suffer repairable local damage at the points of contact, but will effectively protect both buildings from collapse, which could occur if columns were in the place of the walls. Copyright © 2008 John Wiley & Sons, Ltd.
Direct use of PGV for estimating peak nonlinear oscillator displacements
Authors: Akkar Sinan , Küçükdoğan Bilge
Published: May 2008

A predictive model is presented for estimating the peak inelastic oscillator displacements (Sd,ie) from peak ground velocity (PGV). The proposed model accounts for the variation of Sd,ie for bilinear hysteretic behavior under constant ductility (µ) and normalized lateral strength ratio (R) associated with postyield stiffness ratios of α=0 and 5%. The regression coefficients are based on a ground‐motion database that contains dense‐to‐stiff soil site recordings at distances of up to 30 km from the causative fault. The moment magnitude (M) range of the database is 5.2⩽M⩽7.6 and the ground motions do not exhibit pulse‐dominant signals. Confined to the limitations imposed by the ground‐motion database, the model can estimate Sd,ie by employing the PGV predictions obtained from the attenuation relationships (ground‐motion prediction equations). In this way, the influence of important seismological parameters can be incorporated to the variation of Sd,ie in a fairly rationale manner. This feature of the predictive model advocates its implementation in the probabilistic seismic hazard analysis that employs scalar ground‐motion intensity indices. Various case studies are presented to show the consistent estimations of Sd,ie by the proposed model. The error propagation in the Sd,ie estimations is also discussed when the proposed model is associated with attenuation relationships. Copyright © 2008 John Wiley & Sons, Ltd.
Genomewide linkage scan reveals novel loci modifying age of onset of Huntington's disease in the Venezuelan HD kindreds
Authors: Gayán Javier , Brocklebank Denise , Andresen J. Michael , Alkorta‐Aranburu Gorka , Zameel Cader M. , Roberts Simone A. , Cherny Stacey S. , Wexler Nancy S. , Cardon Lon R. , Housman David E.
Published: May 2008

The age of onset of Huntington's disease (HD) is inversely correlated with the CAG length in the HD gene. The CAG repeat length accounts for 70% of the variability in HD age of onset. However, 90% of individuals worldwide with expanded alleles possess between 40 and 50 CAG repeat lengths in their HD gene. For these people, the size of their repeat only determines 44% of the variability in their age of onset. Once the effect of the CAG repeat has been accounted for, the residual variance in age of onset is a heritable trait. Targeted candidate gene studies and a genome scan have suggested some loci as potential modifiers of the age of onset of HD. We analyzed the large Venezuelan kindreds in which the HD gene was originally identified. These kindreds offer greater analytic power than standard sib‐pair designs. We developed novel pedigree‐member selection procedures to maximize power. Using a 5,858‐single‐nucleotide‐polymorphism marker panel, we performed a genomewide linkage analysis. We discovered two novel loci on chromosome 2. Chromosome 2p25 (logarithm of the odds ratio (LOD)=4.29) and 2q35 (LOD=3.39) may contain genes that modify age of onset. A third linkage peak on chromosome 6q22 (LOD=2.48) may confirm the most promising locus from a previous genome scan. Two other candidate loci are suggestive on chromosome 5 (LOD=3.31 at 5p14 and LOD=3.14 at 5q32). All these regions harbor candidate genes that are potential HD modifier genes. Finding these modifier genes can reveal accessible and promising new therapeutic pathways and targets to ameliorate and cure HD. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
On the utility of gene set methods in genomewide association studies of quantitative traits
Authors: Chasman Daniel I.
Published: May 2008

In genomewide genetic association studies, prior biological knowledge may help distinguish variation that is truly associated with a quantitative trait from the vast majority of unassociated variation that may be significant in hypothesis testing due to chance. However, formal methods for integrating prior biological knowledge into association studies have only been proposed recently, and their potential utility has not been thoroughly evaluated. Herein, gene set methods from genomewide analysis of gene expression data are adapted for application to genomewide genetic analysis of quantitative traits. The proposed gene set method was tested in simulations with gene sets that included up to 500 total variants, among which up to 20 collectively explained 5% of the variance. In a population of 1,000 individuals, the gene set method was largely more efficient at detecting truly associated variants in these gene sets than a comparably calibrated conventional approach relying on P‐values alone. While extremely strong associations remain best identified by conventional methods, the gene set approach may provide a complementary mode of analysis for revealing the full spectrum of genes that influence a quantitative trait. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
A general method for linkage disequilibrium correction for multipoint linkage and association
Authors: Kurbasic Azra , Hössjer Ola
Published: May 2008

Lately, many different methods of linkage, association or joint analysis for family data have been invented and refined. Common to most of those is that they require a map of markers that are in linkage equilibrium. However, at the present day, high‐density single nucleotide polymorphisms (SNPs) maps are both more inexpensive to create and they have lower genotyping error. When marker data is incomplete, the crucial and computationally most demanding moment in the analysis is to calculate the inheritance distribution at a certain position on the chromosome. Recently, different ways of adjusting traditional methods of linkage analysis to denser maps of SNPs in linkage disequilibrium (LD) have been proposed. We describe a hidden Markov model which generalizes the Lander‐Green algorithm. It combines Markov chain for inheritance vectors with a Markov chain modelling founder haplotypes and in this way takes account for LD between SNPs. It can be applied to association, linkage or combined association and linkage analysis, general phenotypes and arbitrary score functions. We also define a joint likelihood for linkage and association that extends an idea of Kong and Cox (1997 Am. J. Hum. Genet. 61: 1179–1188) for pure linkage analysis. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
The power of independent types of genetic information to detect association in a case‐control study design
Authors: Won Sungho , Elston Robert C.
Published: May 2008

There have been many single nucleotide polymorphism‐based tests suggested for association analysis in a case‐control design. The possible evidence for association comprises three types of information: differences between cases and controls in allele frequencies, in parameters for Hardy Weinberg disequilibrium (HWD) and in parameters for linkage disequilibrium (LD). Here, first we find the pairwise covariances between statistics that measure these three types of information and show that the statistics are asymptotically trivariate normally distributed. Then we compare their power analytically to determine the most informative statistics according to the disease model. Our results show that differences in parameters for HWD are informative for dominant and recessive disease models, while differences in allele frequencies and in parameters for LD are generally informative except for rare recessive disease models. There is mutual independence of the statistics that detect these three differences under Hardy Weinberg equilibrium at the marker locus and linkage equilibrium between markers in the population. Knowing the pairwise covariances between the statistics makes it possible to define statistics that are mutually independent. This allows us to perform sequential analyses of the same data without the need to adjust significance levels for all the multiple analyses being performed on the same data set. As a result we can have improved flexible strategies to increase the power of genome‐wide association studies without requiring the collection of a new, independent sample. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Age and region‐specific responses of microglia, but not astrocytes, suggest a role in selective vulnerability of dopamine neurons after 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine exposure in monkeys
Authors: Kanaan Nicholas M. , Kordower Jeffrey H. , Collier Timothy J.
Published: May 2008

Little is known about the effects of aging, the strongest risk factor for Parkinson's disease (PD), on glial responses to dopamine (DA) neuron degeneration in midbrain subregions that display selective vulnerability to degeneration. We evaluated the impact of aging on astrocytes and microglia in a regionally specific manner in a monkey model of PD. 1‐Methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) was delivered unilaterally via the internal carotid artery of young, middle‐aged, and old‐aged rhesus monkeys. Astrocytes and microglia were identified using glial fibrillary acidic protein and human leukocyte antigen‐DR (HLA‐DR) immunolabeling, respectively. Glial reactivity was assessed using (1) stereological cell counting, (2) fluorescence intensity, and (3) a morphology rating scale. In the midbrain contralateral and ipsilateral to the MPTP injection, astrocyte number and intensity did not change with age. In both sides of the midbrain, cellular morphology suggested astrocyte hypertrophy in middle‐age dissipated in old‐age, irrespective of DA subregion and regional differences in vulnerability to degeneration. In the contralateral midbrain, microglia became mildly activated (increased cell number and intensity, and morphological changes) with advancing age. Inflammation was evident at 3 months postlesion by severe microglial activation in the ipsilateral midbrain. HLA‐DR fluorescence intensity and an abundance of activated microglia (based on morphological criteria) were consistently exacerbated in the vtSN of both sides of the midbrain. These results suggest the glial responses accompanying aging and DA neuron degeneration following a toxic insult represent persistent alterations in the microenvironment of surviving DA neurons that are important factors in understanding regional differences in susceptibility to degeneration. © 2008 Wiley‐Liss, Inc.
Schwann cell precursors transplanted into the injured spinal cord multiply, integrate and are permissive for axon growth
Authors: Agudo M. , Woodhoo A. , Webber D. , Mirsky R. , Jessen K.R. , Mcmahon S.B.
Published: May 2008

There is a strong current interest in the use of cell transplantation for the treatment of spinal cord injuries. We report here the novel and potentially useful properties of an early cell in the Schwann cell lineage, the Schwann cell precursor (SCP). The experiments reveal a striking difference between these cells and Schwann cells when transplanted into the CNS. Unlike Schwann cells, SCPs thrive in the CNS where they initially proliferate rapidly but then fall out of division, thus effectively filling up the large cystic cavities formed following crush injury, while avoiding tumor formation. By 8 weeks, SCPs had started to express S100β protein, a marker that differentiates Schwann cells from SCPs and had formed an apparently stable, vascularized cell mass, which created a continuous cellular bridge across the cystic cavities. The formation of the surrounding glial scar was reduced by local spread of the transplanted cells into the surrounding CNS tissue, where the cells integrated intimately with astrocytes and attenuated the physical barrier they normally form. SCP transplantation also altered and reduced the expression of chondroitin sulfate proteoglycans around the injury site. Caudal to the SCP transplants there was a large increase in the number of axons, compared with that seen in nontransplanted control tissue, showing that the implants effectively support axonal growth or sprouting. SCPs have advantageous attributes for CNS repair, despite the fact that sticky tape removal and ladder crossing tests at 8 weeks did not reveal significant functional improvements when compared with control animals. © 2008 Wiley‐Liss, Inc.
Women and international assignments: Taking stock—a 25‐year review
Authors: Altman Yochanan , Shortland Susan
Published: May 2008

Women's progress into management and, more specifically, into the world of expatriates, is the subject of this review. Despite advances in equal opportunities legislation, women failed to embark on expatriate missions in significant numbers during the 1980s. In the 1990s, more women were offered international assignment opportunities but they remained a negligible minority compared to men. The first decade of the twenty‐first century has witnessed a gradual increase in the number and visibility of women in international assignments. Through a comprehensive review of the literature over the period from 1980 to now, this article charts the emerging themes and changes in the tone of dis‐course: from when organizations were debating whether to “give women a chance” through attempts to identify and remove “blockages” to women's progress to, most recently, structural changes in the expatriate assignment and claims for women's superior affinity to operating internationally. We highlight gaps in the current literature and propose a platform for future research. We conclude with recommendations for practice. © 2008 Wiley Periodicals, Inc.
Work‐life policy implementation: Breaking down or creating barriers to inclusiveness?
Authors: Ryan Ann Marie , Kossek Ellen Ernst
Published: May 2008

Although many employers have adopted policies to supportthe integration of work with personal and family life, expected positive gains are not always real‐ized. One reason for this gap is that practitioners and researchers often overlook how variation in policy implementation and use by different employee stake‐holder groups fosters a culture of inclusiveness. We discuss four ways in which work‐life policies are implemented (the level of supervisor support for use, universality of availability, negotiability, and quality of communication) and show how these affect the degree to which policies are seen as promoting inclusion or exclusion.These implementation attributes affect whether an adopted policy is perceived to fulfill work‐life needs and act to signal the organization's support for individual differences in work identities and life circumstances. Implications for HR practitioners are discussed. © 2008 Wiley Periodicals, Inc.
Diverse succession planning: Lessons from the industry leaders
Authors: Greer Charles R. , Virick Meghna
Published: May 2008

Although practitioners and academics alike have argued for succession planning practices that facilitate better talent identification and creation of stronger “bench strength,” there has been little attention to the incorporation of gender and racial diversity with succession planning.We discuss practices and competencies for incorporating diversity with succession planning and identify methods for developing women and minorities as successors for key positions. Improvements in strategy, leadership, planning, development, and program management processes are suggested. Recommendations for process improvement are developed from the diversity and succession planning literatures and interviews of 27 human resource professionals from a broad range of industries. © 2008 Wiley Periodicals, Inc.
Hepatitis B virus X protein induces apoptosis by enhancing translocation of Bax to mitochondria
Authors: Kim Hye Jin , Kim Sang Yong , Kim Jinchul , Lee Heemin , Choi Misun , Kim Jeong Ki , Ahn Jeong Keun
Published: May 2008

Hepatitis B virus X protein (HBx) is essential for viral replication and plays an important role in viral pathogenesis. HBx transactivates many viral and cellular genes and participates in cellular signal transduction pathways, proliferation, and apoptosis. In the present study, we report that HBx induces apoptosis by enhancing the translocation of Bax to mitochondria, followed by inducing the loss of mitochondrial membrane potential and release of cytochrome C. In addition, Bcl‐2, inhibitor of Bax, rescues the disruption of mitochondrial membrane potential and DNA fragmentation induced by serum starvation in HepG2‐X cells expressing HBx. We also found that HBx binds directly to Bax and interferes with the interaction between Bax and 14‐3‐3ε to enhance the translocation of Bax to mitochondria. Taken together, our data suggest that HBx induces apoptosis by interacting with Bax and enhancing its translocation to mitochondria. © 2008 IUBMB IUBMB Life, 60(7): 473–480, 2008
Role of xenobiotic transporters in bacterial drug resistance and virulence
Authors: Nishino Kunihiko , Yamaguchi Akihito
Published: May 2008

Since the discovery of antibiotic therapeutics, the battles between humans and infectious diseases have never been stopped. Humans always face the appearance of a new bacterial drug‐resistant strain followed by new antibiotic development. However, as the genome sequences of infectious bacteria have been gradually determined, a completely new approach has opened. This approach can analyze the entire gene resources of bacterial drug resistance. Through analysis, it may be possible to discover the underlying mechanism of drug resistance that will appear in the future. In this review article, we will first introduce the method to analyze all the xenobiotic transporter genes by using the genomic information. Next, we will discuss the regulation of xenobiotic transporter gene expression through the two‐component signal transduction system, the principal environmental sensing and response system in bacteria. Furthermore, we will also introduce the virulence roles of xenobiotic transporters, which is an ongoing research area. © 2008 IUBMB IUBMB Life, 60(9): 569–574, 2008
Evolution of the passive film on mechanically damaged nitinol
Authors: Schroeder Valeska
Published: May 2008

The corrosion behavior of Nitinol‐based medical implants is critical to their success in vivo. Contemporary Nitinol‐based medical implants are typically chemically passivated or electrochemically polished to form a protective passive film. However, mechanically formed surfaces caused by handling damage, fretting, or fatigue fracture may also be present on a device in vivo. In this study, mechanically polished surfaces are used to simulate mechanically damaged surfaces such that analytical techniques, including electrochemical impedance spectroscopy, open circuit potential monitoring, X‐ray photoelectron spectroscopy (XPS), and Mott‐Schottky analysis may be used to monitor the evolution of the passive film on mechanically damaged Nitinol. These mechanically polished Nitinol surfaces are compared with chemically passivated and electrochemically polished Nitinol surfaces and mechanically polished titanium surfaces in phosphate buffered saline solution. The mechanically polished Nitinol exhibits lower impedance at low frequencies, empirically modeled to a thinner film with lower film resistance than chemically passivated and electrochemically polished Nitinol and mechanically polished titanium. Moreover, the passive film on mechanically polished Nitinol continues to develop over time, increasing in its thickness and film resistance. This characterization demonstrates that mechanically formed surfaces may be initially less protective than chemically passivated and electrochemically polished Nitinol surfaces, but continue to become thicker and more resistant to electrochemical reactions with exposure to saline solution. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Bioactive interpenetrating polymer network hydrogels that support corneal epithelial wound healing
Authors: Myung David , Farooqui Nabeel , Zheng Luo Luo , Koh Wongun , Gupta Sarita , Bakri Amit , Noolandi Jaan , Cochran Jennifer R. , Frank Curtis W. , Ta Christopher N.
Published: May 2008

The development and characterization of collagen‐coupled poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) interpenetrating polymer network hydrogels is described. Quantitative amino acid analysis and FITC‐labeling of collagen were used to determine the amount and distribution of collagen on the surface of the hydrogels. The bioactivity of the coupled collagen was detected by a conformation‐specific antibody and was found to vary with the concentration of collagen reacted to the photochemically functionalized hydrogel surfaces. A wound healing assay based on an organ culture model demonstrated that this bioactive surface supports epithelial wound closure over the hydrogel but at a decreased rate relative to sham wounds. Implantation of the hydrogel into the corneas of live rabbits demonstrated that epithelial cell migration is supported by the material, although the rate of migration and morphology of the epithelium were not normal. The results from the study will be used as a guide toward the optimization of bioactive hydrogels with promise in corneal implant applications such as a corneal onlay and an artificial cornea. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Titanium oxide as substrate for neural cell growth
Authors: Carballo‐Vila Mónica , Moreno‐Burriel Berta , Chinarro Eva , Jurado José R. , Casañ‐Pastor Nieves , Collazos‐Castro Jorge E.
Published: May 2008

Titanium oxide has antiinflammatory activity and tunable electrochemical behavior that make it an attractive material for the fabrication of implantable devices. The most stable composition is TiO2 and occurs mainly in three polymorphs, namely, anatase, rutile, and brookite, which differ in its crystallochemical properties. Here, we report the preparation of rutile surfaces that permit good adherence and axonal growth of cultured rat cerebral cortex neurons. Rutile disks were obtained by sinterization of TiO2 powders of commercial origin or precipitated from hydrolysis of Ti(IV)‐isopropoxide. Commercial powders sintered at 1300–1600°C produced rutile surfaces with abnormal grain growth, probably because of impurities of the powders. Neurons cultured on those surfaces survived in variable numbers and showed fewer neurites than on control materials. On the other hand, rutile sintered from precipitated powders had less contaminants and more homogenous grain growth. By adjusting the thermal treatment it was possible to obtain surfaces performing well as substrate for neuron survival for at least 10 days. Some surfaces permitted normal axonal elongation, whereas dendrite growth was generally impaired. These findings support the potential use of titanium oxide in neuroprostheses and other devices demanding materials with enhanced properties in terms of biocompatibility and axon growth promotion. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Covalent surface modification of titanium oxide with different adhesive peptides: Surface characterization and osteoblast‐like cell adhesion
Authors: Dettin Monica , Bagno Andrea , Gambaretto Roberta , Iucci Giovanna , Conconi Maria Teresa , Tuccitto Nunzio , Menti Anna Michela , Grandi Claudio , Di Bello Carlo , Licciardello Antonino , Polzonetti Giovanni
Published: May 2008

A fundamental goal in the field of implantology is the design of innovative devices suitable for promoting implant‐to‐tissue integration. This result can be achieved by means of surface modifications aimed at optimizing tissue regeneration. In the framework of oral and orthopedic implantology, surface modifications concern both the optimization of titanium/titanium alloy surface roughness and the attachment of biochemical factors able to guide cellular adhesion and/or growth. This article focuses on the covalent attachment of two different adhesive peptides to rough titanium disks. The capability of biomimetic surfaces to increase osteoblast adhesion and the specificity of their biological activity due to the presence of cell adhesion signal‐motif have also been investigated. In addition, surface analyses by profilometry, X‐ray photoelectron spectroscopy, and time of flight‐secondary ion mass spectrometry have been carried out to investigate the effects and modifications induced by grafting procedures. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
A novel nano‐porous alumina biomaterial with potential for loading with bioactive materials
Authors: Walpole Andrew R. , Xia Zhidao , Wilson Crispian W. , Triffitt James T. , Wilshaw Peter R.
Published: May 2008

Nano‐porous alumina, with the potential for being loaded with bioactive materials, has been proposed as a novel material for coating implants. In this study, the shear strength of the interface between such nano‐porous anodic aluminium oxide (AAO) coatings and titanium substrates, their biocompatibility, and their potential for pore loading have been investigated. An interface shear strength in excess of 29 MPa was obtained which is comparable with that of conventional plasma sprayed hydroxyapatite implant coatings. The viability and differentiation of MG63 osteoblastic cells co‐cultured on the coating was found to be broadly comparable to that of similar cells co‐cultured on conventional bioinert implant materials such as titanium and fully dense alumina. Extensive pore loading with silica nano‐particles of different sizes and in different combinations was demonstrated throughout the thickness of AAO layers 1 μm and 60 μm thick. This work has demonstrated, that with suitable choice of pore filling materials, this novel coating might simultaneously combat infection, encourage bone regeneration, and secure fixation of the implant to bone. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Contributions of contact activation pathways of coagulation factor XII in plasma
Authors: Chatterjee Kaushik , Guo Zhe , Vogler Erwin A. , Siedlecki Christopher A.
Published: May 2008

Activation of human blood plasma coagulation by contact with hydrophilic or hydrophobic surfaces (procoagulants) is dominated by kallikrein (Kal)‐mediated activation of the blood zymogen FXII (Hageman Factor). Mathematical modeling of prekallikrein (PK)‐deficient platelet‐poor plasma (dPKPPP) and PK‐reconstituted dPKPPP (RdPKPPP) coagulation shows that autoactivation of FXII ($ {\rm{FXII}}\mathop {-\!\!\!-\!\!\!-\!\!\!-\!\!\!\rightarrow}\limits^{{\rm{surface}}} {\rm{FXIIa}}$) produces no more than about 25% of the total FXIIa produced by the intrinsic pathway. Autoactivation and reciprocal‐activation increase in the same proportion with procoagulant surface energy (water‐wettability), whereas total amount of FXIIa produced per‐unit‐area procoagulant remains roughly constant for any particular procoagulant. These results suggest that procoagulant surfaces initiate the intrinsic cascade by producing a bolus of FXIIa in proportion to surface energy or surface area but play no additional role in subsequent molecular events in the cascade. Results further suggest that reciprocal‐activation occurs in proportion to the amount of FXIIa produced by the initiating autoactivation step. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Gap junction intercellular communication: A review of a potential platform to modulate craniofacial tissue engineering
Authors: Rossello Ricardo A. , Kohn David H.
Published: May 2008

Defects in craniofacial tissues, resulting from trauma, congenital abnormalities, oncologic resection or progressive deforming diseases, may result in aesthetic deformity, pain and reduced function. Restoring the structure, function and aesthetics of craniofacial tissues represents a substantial clinical problem in need of new solutions. More biologically‐interactive biomaterials could potentially improve the treatment of craniofacial defects, and an understanding of developmental processes may help identify strategies and materials that can be used in tissue engineering. One such strategy that can potentially advance tissue engineering is cell–cell communication. Gap junction intercellular communication is the most direct way of achieving such signaling. Gap junction communication through connexin‐mediated junctions, in particular connexin 43 (Cx43), plays a major role bone development. Given the important role of Cx43 in controlling development and differentiation, especially in bone cells, controlling the expression of Cx43 may provide control over cell‐to‐cell communication and may help overcome some of the challenges in craniofacial tissue engineering. Following a review of gap junctions in bone cells, the ability to enhance cell–cell communication and osteogenic differentiation via control of gap junctions is discussed, as is the potential utility of this approach in craniofacial tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Noncoding RNAs produced by oncogenic human herpesviruses
Authors: Swaminathan Sankar
Published: May 2008

The two human herpesviruses that are causally associated with cancer are Epstein–Barr virus and Kaposi's sarcoma‐associated herpesvirus (KSHV). Both are lymphocryptoviruses that establish latency in B lymphocytes and persist for the lifetime of the host. EBV and KSHV are both linked to a variety of lymphomas. EBV is also a causative agent or cofactor in epithelial malignancies such as nasopharyngeal carcinoma whereas Kaposi's sarcoma is of endothelial cell origin. Both viruses encode a limited number of proteins during latent replication that are important for growth transformation and evasion of the immune system. In addition, they express noncoding RNAs during both latent and lytic infection. Many of these RNAs have been highly conserved during evolution and are expressed in a wide variety of clinical settings, suggesting their fundamental importance in the viral life cycle. The function of some of these RNAs such as the nuclear EBV EBER RNAs remains elusive although they are some of the most abundant transcripts produced by each virus. Both EBV and KSHV also have recently been shown to encode and express microRNAs. The study of these viral microRNAs is just beginning although several of their cellular and viral gene targets have been established. Viral microRNAs appear to be involved in both modulation of the immune response as well as oncogenesis. Because each target gene may have many microRNAs acting on its mRNA, and each microRNA may have more than one target, there are likely to be many new discoveries regarding the complex interactions of viral microRNAs and host cell genes. J. Cell. Physiol. 216: 321–326, 2008. © 2008 Wiley‐Liss, Inc.
Hepatic stellate cells modulate the differentiation of bone marrow mesenchymal stem cells into hepatocyte‐like cells
Authors: Deng Xing , Chen Yue‐Xiang , Zhang Xin , Zhang Jun‐Ping , Yin Chuan , Yue Hai‐Yan , Lin Yong , Han Ze‐Guang , Xie Wei‐Fen
Published: May 2008

Differentiation of stem cells is tightly regulated by the microenvironment which is mainly composed of nonparenchymal cells. Herein, we investigated effect of hepatic stellate cells (HSCs) in different states on mesenchymal stem cells (MSCs) differentiation. Rat HSCs were isolated and stayed quiescent within 5 days. Primary HSCs were activated by being in vitro cultured for 7 days or cocultured with Kupffer cells for 5 days. MSCs were cocultured with HSCs of different states. Expression of hepatic lineage markers was analyzed by RT‐PCR and immunofluorescence. Glycogen deposition was detected by periodic acid‐schiff staining. MSCs cocultured with HSC‐T6 or Kupffer cell activated HSCs were morphologically transformed into hepatocyte‐like cells. Hepatic‐specific marker albumin was expressed in 78.3% of the differentiated MSCs 2 weeks after initiation of coculture. In addition, the differentiated MSCs also expressed α‐fetoprotein, cytokeratin‐18, glutamine synthetase and phosphoenolpyruvate carboxykinase. Glycogen deposition was detectable in 55.4% of the differentiated MSCs 6 weeks after initiation of coculture. However, the quiescent HSCs or culture activated HSCs did not exert the ability to modulate the differentiation of MSCs. Moreover, Kupffer cell activated HSCs rather than culture activated HSCs expressed hepatocyte growth factor mRNA. We draw the conclusion that fully activated HSCs could modulate MSCs differentiation into hepatocyte‐like cells. J. Cell. Physiol. 217: 138–144, 2008. © 2008 Wiley‐Liss, Inc.
Selection and optimisation of macroporous resin for separation of stilbene glycoside from Polygonum multiflorum Thunb.
Authors: Lv Lishuang , Tang Jian , Ho Chi‐Tang
Published: May 2008

BACKGROUND: 2,3,5,4′‐Tetrahydroxystilbene‐2‐O‐β‐glucopyranoside (SG; a stilbene glycoside) is a major bioactive component of Polygonum multiflorum Thunb. (PM), a popular traditional Chinese herb. In this study a method was developed for the separation of SG from PM on macroporous resins. These were selected and optimised using the linear correlation coefficients of the Langmuir and Freundlich isotherms and a pseudo‐first‐order model to explain the kinetic results. Then dynamic adsorption and desorption experiments were carried out on a column packed with the chosen resin to optimise the separation process.

RESULTS: HPD100 resin gave the best performance in the separation of SG from PM. The optimal parameters were a sample concentration in solution of 3.5 g mL−1, a pH of 4.8, a flow rate of 1.5 mL min−1 and an elution solvent of 40% (v/v) ethanol. Using this scaled‐up column, a product with a final SG content of 819 mg g−1 and a recovery yield of 74.7% was achieved. In addition, pure acicular crystals of SG could be obtained from this product.

CONCLUSION The results showed that HPD100 was the most efficient resin for the separation of SG, which may provide a scientific basis for larger‐scale stilbene glycoside production from PM and other plant extracts. Copyright © 2008 Society of Chemical Industry
Merit pay raises and organization‐based self‐esteem
Authors: Scott Kristin L. , Shaw Jason D. , Duffy Michelle K.
Published: May 2008

We developed and tested a theory of the relationship between merit pay raises and organization‐based self‐esteem (OBSE) in a longitudinal study of hospital employees. We predicted that the positive relationship between merit pay raise size and OBSE would be stronger when pay‐for‐performance (PFP) perceptions were high and predicted further that this interaction would be stronger among older employees. As predicted, merit pay raises were not related to OBSE levels for younger employees, but, among older employees, larger merit raises increased OBSE when PFP perceptions were high and decreased OBSE when PFP perceptions were low. Implications of the study for merit pay theory and practice are addressed. Copyright © 2008 John Wiley & Sons, Ltd.