bluuebunny/crossref_metadata_2025 huggingface dataset:
Need‐to‐know Cultures: an Investigation into Intra‐organisational and Extra‐organisational Knowledge Sharing Cultures in Local Government in the UK
Authors: Deverell Anne Christine , Burnett Simon
Published: August 2012

This paper presents the findings of research that aimed to compare cultures associated with intra‐organisation and extra‐organisational knowledge sharing and to investigate whether the concepts of need‐to‐know culture in each context are related. The research tested the following hypothesis: are organisations that are more open to releasing information to the public through freedom of information (FOI) also better at internal knowledge sharing?

This research used the UK local government sector as a context by targeting self‐completion questionnaires to FOI practitioners in councils in England. The questionnaire asked FOI practitioners to assess attitudes to knowledge sharing and FOI requests within their organisation, providing attitudinal ratings and illustrative comments.

The research found that respondents who thought that their organisation had a stronger knowledge sharing culture also rated the organisation more highly on aspects of FOI culture. This suggests that the different concepts of need‐to‐know culture are related and that it is likely that there are important cultural elements that support both FOI and knowledge sharing.

Freedom of information is a subject with considerable implications for both public and private sector organisations internationally. The research is significant in directly investigating the connections between FOI and knowledge management and in comparing the cultural aspects of these practices in the public sector, a topic where there is little existing literature. The findings of this research will have implications for those trying to overcome need‐to‐know culture within an organisation. Copyright © 2012 John Wiley & Sons, Ltd.
National prevalence and impact of perioperative vagus nerve injury in vestibular schwannoma
Authors: Ward Bryan K. , Francis Howard W. , Best Simon R. , Starmer Heather M. , Akst Lee M. , Gourin Christine G.
Published: August 2012

Objectives/Hypothesis:

Lower cranial nerve injury may be an under‐reported complication of vestibular schwannoma surgery. This study aims to characterize the prevalence of complications associated with vagus nerve injury following vestibular schwannoma surgery and the impact of these complications on patient care.

Study Design:

Retrospective cross‐sectional study.

Methods:

Discharge data from the Nationwide Inpatient Sample for 17,281 patients with vestibular schwannoma who underwent surgery in 2003–2008 were analyzed using cross‐tabulations and multivariate regression modeling.

Results:

Dysphagia was reported in 443 cases (2.6%) and unilateral vocal fold paralysis in 115 cases (0.7%). The mean length of hospitalization was 5.3 days (95% confidence interval [CI], 4.9‐5.7) and was prolonged in patients with dysphagia (mean, 11.7 days; 95% CI, 8.9‐14.4) and in those with unilateral vocal fold paralysis (mean, 12.1 days; 95% CI, 7.3‐16.9). Compared to patients without dysphagia, a diagnosis of dysphagia was associated with advanced comorbidity status (37.0% vs. 18.8%), central nervous system complications (39.3% vs. 15.3%), aspiration pneumonia (7.1% vs. 0.4%), and greater likelihood of requiring medical care at another facility or at home after discharge (48.5% vs. 6.6%, P < .001). Tracheostomy (3.4% vs. 0.8%) and gastrostomy tube placement (20.9% vs. 0.5%) were significantly more likely in patients with dysphagia (P < .0001). After adjusting for other variables, dysphagia, aspiration pneumonia, and tracheostomy were significantly associated with increased length of hospitalization and hospital‐related costs.

Conclusions:

Although infrequently reported in this national inpatient sample, vagus nerve injury‐related symptoms are associated with significantly increased length of hospitalization and costs of care.
Low‐frequency ultrasound for biofilm disruption in chronic rhinosinusitis with nasal polyposis: In vitro pilot study
Authors: Karosi Tamás , Sziklai István , Csomor Péter
Published: August 2012

Objectives/Hypothesis:

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Although biofilms are characterized by an extremely high resistance against chemical and physical agents, low‐frequency ultrasound (LFU) treatment has been suspected to be an efficient and safe method for biofilm disruption.

Study Design:

Basic science experimental study.

Methods:

A total of 10 patients with CRSwNP undergoing endoscopic sinus surgery were analyzed. Two series of identical nasal polyps (n = 20) were processed to hematoxylin‐eosin (HE) and Gram staining and to continuous‐wave LFU treatment (5 minutes, 0.4 MHz, 37°C), respectively.

Results:

Presence of microbial biofilms was confirmed in all patients with CRSwNP. HE staining showed a strong correlation with the results of Gram protocol in biofilm detection. In the LFU‐treated group (n = 10), a significantly decreased inflammatory cell count was found in the subepithelial layer of nasal polyps (P < .001). In addition, bacterial biofilms were completely removed from the surface of the epithelial layer. Microscopic tissue injuries or significant temperature changes were not detected due to LFU treatment.

Conclusions:

Between in vitro conditions, LFU treatment appeared to be a reliable and microscopically safe method for the disruption of microbial biofilms in CRSwNP. These results may provide a basis for a prospective human study investigating the efficacy and safety of this therapeutic modality alone or in combination with antibiotics or topical steroids in biofilm‐positive cases of CRSwNP. Laryngoscope, 2013
Poly(L‐lactide) Nanoparticles via Ring‐Opening Polymerization in Non‐aqueous Emulsion
Authors: Dorresteijn Robert , Haschick Robert , Klapper Markus , Müllen Klaus
Published: August 2012

The preparation of poly(L‐lactide) nanoparticles via ring‐opening polymerization (ROP) of L‐lactide is conducted in non‐aqueous emulsion. In this process, acetonitrile is dispersed in either cyclohexane or n‐hexane as the continuous phase and stabilized by a PI‐b‐PEO, respectively, a PI‐b‐PS copolymer as emulsifier. The air and moisture sensitive N‐heterocyclic carbene 1,3‐bis(2,4,6‐trimethylphenyl)‐2‐ididazolidinylidene (SIMes) catalyzes the polymerization of L‐lactide at ambient temperatures. Spherical poly(L‐lactide) nanoparticles with an average diameter of 70 nm and a tunable molecular weight are generated. Hence, the non‐aqueous emulsion technique demonstrates its good applicability toward the generation of well‐defined poly(L‐lactide) nanoparticles under very mild conditions.
Synthesis and Characterization of Reinforced Poly(ethylene glycol)/Chitosan Hydrogel as Wound Dressing Materials
Authors: Chen Szu‐Hsien , Tsao Ching‐Ting , Chang Chih‐Hao , Lai Yi‐Ting , Wu Ming‐Fung , Liu Zheng‐Wei , Chuang Ching‐Nan , Chou Hung‐Chia , Wang Chih‐Kuang , Hsieh Kuo‐Haung
Published: August 2012

PEG is used to reinforce chitosan‐based hydrogels through the formation of ester and amide linkages. The reinforced PEG/chitosan (RPC) hydrogels exhibit significant enhancements in tensile modulus and elongation compared with neat chitosan. Other properties are thoroughly investigated and indicate that the physicochemical and in vitro degradation properties of the RPC hydrogels depend on the amount and molecular weight of the PEG. The RPC hydrogels can control evaporative water loss at a suitable rate to maintain a moist environment. In terms of in vitro biological properties, 3T3 fibroblasts show good viability with the RPC hydrogels, which indicates that the RPC hydrogels may be used as wound dressing materials.

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Tunable Thermo‐Responsive Poly(N‐vinylcaprolactam) Cellulose Nanofibers: Synthesis, Characterization, and Fabrication
Authors: Webster Martial , Miao Jianjun , Lynch Brandon , Green Da'Sean , Jones‐Sawyer Reginald , Linhardt Robert J. , Mendenhall Juana
Published: August 2012

Temperature‐responsive PVCL homopolymers and functional PVCL polymers containing carboxylic acids are prepared in organic and aqueous solutions. PVCL bulk polymers are characterized using 1H NMR, photometry, ATR‐FTIR, and thermal analysis. A finite phase transition at 37–40 °C occurs in aqueous solutions of PVCL and PVCL‐COOH. PVCL and PVCL‐COOH polymers are electrospun into fibers ranging from 100 to 2300 nm in diameter. PVCL/cellulose bi‐component films are obtained by electrospinning of CA and PVCL followed by alkaline hydrolysis. These tunable thermo‐responsive PVCL/cellulose nanofibers have potential applications in developing affinity membranes.

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Effect of Maleic‐Anhydride Grafting on the Physical and Mechanical Properties of Poly(L‐lactic acid)/Starch Blends
Authors: Hwang Sung Wook , Shim Jin Kie , Selke Susan , Soto‐Valdez Herlinda , Rubino Maria , Auras Rafael
Published: August 2012

MA is grafted onto both PLLA and starch in an internal mixer in the presence of DCP in a one‐step reactive compatibilization process. The effect of maleation of MA on the physical and mechanical properties and morphology of the blends was assessed. The onset decomposition temperature of the PLLA/starch blends decreased as the starch content increases due to the lower thermal stability of starch and the low effect of the maleation reaction on the thermal stability of the blends. PLLA/starch blends without grafted MA showed higher crystallinity as the starch content increased. Reactive compatibilized blends with less than 20 wt% starch had higher storage modulus, indicating that the compatibility between the two phases was improved.

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Epoxy/BaTiO3 Light‐Cured Composites as Organic Capacitors
Authors: Sangermano Marco , Lombardi Mariangela , Guerriero Andrea , Kortaberria Galder , Mondragon Inaki , Pirri Fabrizio , Montanaro Laura
Published: August 2012

Epoxy/BaTiO3 hybrid materials are prepared as good candidates for organic capacitors. The hybrid system is cured by using camphorquinone and a iodonium salt through a free‐radical promoted cationic polymerization using a long‐wavelength tungsten halogen lamp. The cured films are fully characterized. Morphological characterization shows a well‐dispersed inorganic phase within the organic matrix. Electrical characterization demonstrates a linear increase of the dielectric constant with increasing filler content, while low dielectric loss values are obtained.

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Poly(2‐ethyl‐2‐oxazoline) as Matrix Excipient for Drug Formulation by Hot Melt Extrusion and Injection Molding
Authors: Claeys Bart , Vervaeck Anouk , Vervaet Chris , Remon Jean Paul , Hoogenboom Richard , De Geest Bruno G.
Published: August 2012

Here we evaluate poly(2‐ethyl‐2‐oxazoline)s (PEtOx) as a matrix excipient for the production of oral solid dosage forms by hot melt extrusion (HME) followed by injection molding (IM). Using metoprolol tartrate as a good water‐soluble model drug we demonstrate that drug release can be delayed by HME/IM, with the release rate controlled by the molecular weight of the PEtOx. Using fenofibrate as a lipophilic model drug we demonstrate that relative to the pure drug the dissolution rate is strongly enhanced by formulation in HME/IM tablets. For both drug molecules we find that solid solutions, i.e. molecularly dissolved drug in a polymeric matrix, are obtained by HME/IM.
An Overview of Phenylcyclopropylamine Derivatives: Biochemical and Biological Significance and Recent Developments
Authors: Khan Mohammed Naseer Ahmed , Suzuki Takayoshi , Miyata Naoki
Published: August 2012

trans‐2‐Phencylcyclopropylamine (2‐PCPA), a potent, clinically used antidepressant, affects monoamine neurotransmitter levels by inhibiting the main metabolizing enzymes, monoamine oxidases (MAOs). However, the antidepressant action of this compound was not fully explained by its effects on MAOs due to its wide variety of biological effects. 2‐PCPA also affects depression‐associated pathophysiological pathways, and linked with increased levels of trace amines in brain, upregulation of GABAB receptors (where GABA is gamma amino butyric acid), modulation of phospholipid metabolism, and interference with various cytochrome P450 (CYP) enzymes. Consequently, despite its adverse effects and limited clinical applicability, 2‐PCPA has attracted interest as a structural scaffold for the development of mechanism‐based inhibitors of various enzymes, including lysine‐specific demethylase 1 (LSD1), which is a possible target for cancer chemotherapy. In the recent years, many reports have appeared in the literature based on 2‐PCPA scaffold and their potential medicinal implications. This review mainly focuses on the medicinal chemistry aspects including drug design, structure–activity relationships (SAR), biological and biochemical properties, and mechanism of actions of 2‐PCPA and its derivatives. Furthermore, we also highlight recent advance in this area and discuss their future applications for beneficial therapeutic effects.
Inverse problems for Sturm–Liouville operators with interior discontinuities and boundary conditions dependent on the spectral parameter
Authors: Wang Yu Ping
Published: August 2012

In this paper, we discuss the inverse problem for Sturm–Liouville operators with arbitrary number of interior discontinuities and boundary conditions having fractional linear function of spectral parameter on the finite interval [0,1]. Using Weyl function techniques, we establish some uniqueness theorems for the Sturm–Liouville operator. Copyright © 2012 John Wiley & Sons, Ltd.
Extended space–time finite elements for landslide dynamics
Authors: Pasenow F. , Zilian A. , Dinkler D.
Published: August 2012

The paper introduces a methodology for numerical simulation of landslides experiencing considerable deformations and topological changes. Within an interface capturing approach, all interfaces are implicitly described by specifically defined level‐set functions allowing arbitrarily evolving complex topologies. The transient interface evolution is obtained by solving the level‐set equation driven by the physical velocity field for all three level‐set functions in a block Jacobi approach. The three boundary‐coupled fluid‐like continua involved are modeled as incompressible, governed by a generalized non‐Newtonian material law taking into account capillary pressure at moving fluid–fluid interfaces. The weighted residual formulation of the level‐set equations and the fluid equations is discretized with finite elements in space and time using velocity and pressure as unknown variables. Non‐smooth solution characteristics are represented by enriched approximations to fluid velocity (weak discontinuity) and fluid pressure (strong discontinuity). Special attention is given to the construction of enriched approximations for elements containing evolving triple junctions. Numerical examples of three‐fluid tank sloshing and air–water‐liquefied soil landslides demonstrate the potential and applicability of the method in geotechnical investigations. Copyright © 2012 John Wiley & Sons, Ltd.
A micromechanical model of distributed damage due to void growth in general materials and under general deformation histories
Authors: Reina Celia , Li Bo , Weinberg Kerstin , Ortiz Michael
Published: August 2012

We develop a multiscale model of ductile damage by void growth in general materials undergoing arbitrary deformations. The model is formulated in the spirit of multiscale finite element methods (FE 2), that is, the macroscopic behavior of the material is obtained by a simultaneous numerical evaluation of the response of a representative volume element. The representative microscopic model considered in this work consists of a space‐filling assemblage of hollow spheres. Accordingly, we refer to the present model as the packed hollow sphere (PHS) model. A Ritz–Galerkin method based on spherical harmonics, specialized quadrature rules, and exact boundary conditions is employed to discretize individual voids at the microscale. This discretization results in material frame indifference, and it exactly preserves all material symmetries. The effective macroscopic behavior is then obtained by recourse to Hill's averaging theorems. The deformation and stress fields of the hollow spheres are globally kinematically and statically admissible regardless of material constitution and deformation history, which leads to exact solutions over the entire representative volume under static conditions. Excellent convergence and scalability properties of the PHS model are demonstrated through convergence analyses and examples of application. We also illustrate the broad range of material behaviors that are captured by the PHS model, including elastic and plastic cavitation and the formation of a vertex in the yield stress of porous metals at low triaxiality. This vertex allows ductile damage to occur under shear‐dominated conditions, thus overcoming a well‐known deficiency of Gurson's model. Copyright © 2012 John Wiley & Sons, Ltd.
Advances in membrane proteomics and cancer biomarker discovery: Current status and future perspective
Authors: Shukla Hem D. , Vaitiekunas Paulius , Cotter Robert J.
Published: August 2012

Membrane proteomic analysis has been proven to be a promising tool for identifying new and specific biomarkers that can be used for prognosis and monitoring of various cancers. Membrane proteins are of great interest particularly those with functional domains exposed to the extracellular environment. Integral membrane proteins represent about one‐third of the proteins encoded by the human genome and assume a variety of key biological functions, such as cell‐to‐cell communication, receptor‐mediated signal transduction, selective transport, and pharmacological actions. More than two‐thirds of membrane proteins are drug targets, highlighting their immensely important pharmaceutical significance. Most plasma membrane proteins and proteins from other cellular membranes have several PTMs; for example, glycosylation, phosphorylation, and nitrosylation, and moreover, PTMs of proteins are known to play a key role in tumor biology. These modifications often cause change in stoichiometry and microheterogeneity in a protein molecule, which is apparent during electrophoretic separation. Furthermore, the analysis of glyco‐ and phosphoproteome of cell membrane presents a number of challenges mainly due to their low abundance, their large dynamic range, and the inherent hydrophobicity of membrane proteins. Under pathological conditions, PTMs, such as phosphorylation and glycosylation are frequently altered and have been recognized as a potential source for disease biomarkers. Thus, their accurate differential expression analysis, along with differential PTM analysis is of paramount importance. Here we summarize the current status of membrane‐based biomarkers in various cancers, and future perspective of membrane biomarker research.
Validation of regulated protein phosphorylation events in yeast by quantitative mass spectrometry analysis of purified proteins
Authors: Reiter Wolfgang , Anrather Dorothea , Dohnal Ilse , Pichler Peter , Veis Jiri , Grøtli Morten , Posas Francesc , Ammerer Gustav
Published: August 2012

Global phosphoproteomic studies based on MS have generated qualitative and quantitative data describing protein phosphorylation events in various biological systems. Since high‐throughput data for protein modifications are inherently incomplete, we developed a strategy to extend and validate such primary datasets. We selected interesting protein candidates from a global screen in yeast and employed a modified histidine biotin tag that allows tandem affinity purifications of our targets under denaturing conditions. Products in question can be digested directly from affinity resins and phosphopeptides can be further enriched via TiO2 before MS analysis. Our robust protocol can be amended for SILAC as well as iTRAQ quantifications or label‐free approaches based on selective reaction monitoring, allowing completion of the phosphorylation pattern in a first step, followed by a detailed analysis of the phosphorylation kinetics. We exemplify the value of such a strategy by an in‐depth analysis of Pan1, a highly phosphorylated factor involved in early steps of endocytosis. The study of Pan1 under osmotic stress conditions in different mutant backgrounds allowed us to differentiate between mitogen‐activated protein kinase Hog1 driven and Hog1 independent stress responses.
Synthesis and characterization of organic–inorganic hybrid block copolymers containing a fully condensed ladder‐like polyphenylsilsesquioxane
Authors: Lee Albert Sung Soo , Choi Seung‐Sock , Lee He Seung , Jeon Hyeon Yeol , Baek Kyung‐Youl , Hwang Seung Sang
Published: August 2012

A series of inorganic–organic hybrid block copolymers were synthesized via atom transfer radical polymerization using a fully condensed, ladder‐like structured polyphenylsilsesquioxane end‐functionalized macroinitiator. The inorganic portion, ladder‐like polyphenylsilsesquioxane, was synthesized in a one‐batch, base‐catalyzed system, whereas organic hard and soft monomers, styrene, and n‐butyl acrylate, were polymerized and copolymerized on the ends of the linear, inorganic backbone. Synthesized hybrid diblock, triblock, and random copolymers were characterized by 1H NMR, 29Si NMR, gel permeation chromatography, static light scattering, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Hybrid block copolymers were well‐defined with low polydispersity (<1.4) and exhibited enhanced thermal properties in the form of increased glass transition and degradation onset temperatures over their organic analogues.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis of enantiopure homo and copolymers by raft polymerization and investigation of their enantioselective lipase‐catalyzed esterification
Authors: Yeniad Bahar , Köklükaya N. Oruç , Naik Hemantkumar , Fijten M. W. Martin , Koning Cor E. , Heise Andreas
Published: August 2012

Homo and copolymers were synthesized from enantionpure (R)‐ and (S)‐1‐(4‐vinylphenyl)ethanol by reversible addition‐fragmentation chain transfer polymerization. The polymerization conditions were optimized resulting in dioxane as the preferred reaction solvent. First‐order polymerization kinetics and well‐defined enantiopure homopolymers with low dispersities were obtained. In agreement with their enantiomeric composition, the (R) and (S)‐polymers gave opposite optical rotation of light. Polymer analogous esterification of the chiral hydroxy groups catalyzed by enantioselective Candida antarctica Lipase B was strongly (R)‐selective. Esterification on the homopolymer and copolymers could be achieved to a maximum of around 50 %. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis of bicyclic bis(γ‐butyrolactone) derivatives bearing sulfide moieties and their alternating copolymers with epoxide
Authors: Ohsawa Sousuke , Morino Kazuhide , Sudo Atsushi , Endo Takeshi
Published: August 2012

A series of bicyclic bis(γ‐butyrolactone)s (BBL) bearing sulfide moiety 2 were readily synthesized from a precursor BBL bearing isopropenyl group 1. This efficient and versatile synthesis of 2 was achieved by a highly reliable radical addition reaction of thiols to the C‐C double bond in the isopropenyl group 2 underwent anionic copolymerization with glycidyl phenyl ether in a 1:1 alternating manner to give a series of the corresponding polyester 3, of which side chains inherited the sulfide group from 2. The glass transition temperatures (Tg) of 3 showed clear dependence on the flexibility of the sulfide side chains. The scope of this copolymerization system was further expanded by synthesizing a bifunctional BBL 4 from 1 with using hexanedithiol and performing its copolymerization with bisphenol A diglycidyl ether 5. The copolymerization gave the corresponding networked polymer in high yield. During the copolymerization, the volume expanding nature of the double ring‐opening reaction of 4 contributed to the efficient compensation of the intrinsic volume shrinkage of the ring‐opening of epoxide to achieve a shrinkage‐free curing system. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Photoinitiated cationic polymerization of limonene 1,2‐oxide and α‐pinene oxide
Authors: Park Han Jin , Ryu Chang Y. , Crivello James V.
Published: August 2012

Limonene 1,2‐oxide (LMO) and α‐pinene oxide (α‐PO) are two high reactivity biorenewable monomers that undergo facile photoinitiated cationic ring‐opening polymerizations using both diaryliodonium salt and triarylsufonium salt photoinitiators. Comparative studies showed that α‐PO is more reactive than LMO, and this is because it undergoes a simultaneous double ring‐opening reaction involving both the epoxide group and the cyclobutane ring. It was also observed that α‐PO also undergoes more undesirable side reactions than LMO. The greatest utility of these two monomers is projected to be as reactive diluents in crosslinking photocopolymerizations with multifunctional epoxide and oxetane monomers. Prototype copolymerization studies with several difunctional monomers showed that LMO and α‐PO were effective in increasing the reaction rates and shortening the induction periods of photopolymerizations of these monomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Modeling Study on the Generation of Reactive Oxygen Species in Atmospheric Radio‐Frequency Helium–Oxygen Discharges
Authors: He Jin , Zhang Yuantao T
Published: August 2012

Atmospheric radio‐frequency (rf) plasmas have attracted an increasing amount of attention due to its unparalleled capability for production of chemically reactive oxygen species (ROS). In this paper, we explore a one‐dimensional fluid model, incorporating 17 species and 65 key reactions, to investigate the generation mechanism of ROS in atmospheric He/O2 rf discharges. From the computational data the atomic oxygen density is almost linearly dependent on the power density and its largest value was observed at the oxygen admixture of 0.6% while altering the oxygen admixture at a constant power density, and an optimal oxygen admixture level of 0.3% is also found to produce the largest density of single delta oxygen (SDO) at a given power density.The dominant production and destruction reactions of ROS are also discussed based on the simulation results.

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Engineering metal precipitate size distributions to enhance gettering in multicrystalline silicon
Authors: Hofstetter Jasmin , Fenning David P. , Lelièvre Jean‐François , del Cañizo Carlos , Buonassisi Tonio
Published: August 2012

The extraction of metal impurities during phosphorus diffusion gettering (PDG) is one of the crucial process steps when fabricating high‐efficiency solar cells using low‐cost, lower‐purity silicon wafers. In this work, we show that for a given metal concentration, the size and density of metal silicide precipitates strongly influences the gettering efficacy. Different precipitate size distributions can be already found in silicon wafers grown by different techniques. In our experiment, however, the as‐grown distribution of precipitated metals in multicrystalline Si sister wafers is engineered through different annealing treatments in order to control for the concentration and distribution of other defects. A high density of small precipitates is formed during a homogenization step, and a lower density of larger precipitates is formed during extended annealing at 740 °C. After PDG, homogenized samples show a decreased interstitial iron concentration compared to as‐grown and ripened samples, in agreement with simulations.
Optical transition energies in armchair‐edge graphene nanoribbons under uniaxial strain
Authors: Han Mei , Zhang Yong
Published: August 2012

The optical transition energies of armchair‐edge graphene nanoribbons (AGNRs) under uniaxial strain have been studied based on tight‐binding model including up to third‐nearest‐neighbor carbon–carbon interaction and edge distortion. Obtained results show that the optical transition energies of AGNRs are sensitive to the uniaxial strain. The variations of optical transition energies on the uniaxial strains are linear but not monotonic, displaying an “N” or an upside‐down “N” type feature. The mechanism underlying the strain effects on optical transition energies has been revealed. The obtained optical transition energies can be used to help evaluating the future experiments on optical properties of strained AGNRs.
Lead‐vacancy‐related hole centers in lead tungstate crystals
Authors: Laguta Valentin , Nikl Martin , Zazubovich Svetlana
Published: August 2012

After UV irradiation of PbWO4 crystals at T > 140 K in the energy range around 4.05 eV, besides the thermally stimulated luminescence (TSL) peak at ≈193 K arising from electron {Pb+ − VO} centers, a TSL peak at about 225 K appears. We suggest that this ≈225 K TSL peak arises from the thermal destruction of non‐paramagnetic hole centers of the {VPb + 2h}‐type (two holes trapped at the oxygen ions in the vicinity of a single lead vacancy VPb). The recombination of thermally or optically released electrons with these hole centers at T > 140 K is accompanied with green G(II) emission peaking at about 2.5 eV. The processes of photo‐thermally stimulated creation of VPb‐related hole centers have been studied.
A neutron reflectometry study on silicon self‐diffusion at 900 °C
Authors: Hüger E. , Kube R. , Bracht H. , Stahn J. , Geue T. , Schmidt H.
Published: August 2012

We carried out experiments of self‐diffusion in single crystalline silicon at a temperature of 900 °C by a method that is based on neutron reflectometry in combination with 29Si/28Si isotope multilayers. The experimental reflectivity pattern shows artificial Bragg peaks due to isotope periodicity and is fitted by the program Parratt32. Diffusivities are calculated from the roughness parameter of the isotope interfaces. The results are compared to that one obtained from a simple analytical expression on the reduction of the Bragg peak. The results exhibit that both methods deliver identical diffusivities within error limits. The diffusivity of 4 × 10−22 m2 · s−1 does not depend on annealing time for diffusion on a length scale of 1–6 nm and is in good accordance to literature data, ranging between 1 and 10 × 10−22 m2 · s−1. The results demonstrate that the neutron reflectometry method is well suited to determine self‐diffusivities in single crystalline silicon at very short length scales.
Collaborative mapping of an earthquake‐damaged building via ground and aerial robots
Authors: Michael Nathan , Shen Shaojie , Mohta Kartik , Mulgaonkar Yash , Kumar Vijay , Nagatani Keiji , Okada Yoshito , Kiribayashi Seiga , Otake Kazuki , Yoshida Kazuya , Ohno Kazunori , Takeuchi Eijiro , Tadokoro Satoshi
Published: August 2012

We report recent results from field experiments conducted with a team of ground and aerial robots engaged in the collaborative mapping of an earthquake‐damaged building. The goal of the experimental exercise is the generation of three‐dimensional maps that capture the layout of a multifloor environment. The experiments took place in the top three floors of a structurally compromised building at Tohoku University in Sendai, Japan that was damaged during the 2011 Tohoku earthquake. We provide details of the approach to the collaborative mapping and report results from the experiments in the form of maps generated by the individual robots and as a team. We conclude by discussing observations from the experiments and future research topics. © 2012 Wiley Periodicals, Inc.
Photoelectron spectroscopic studies of the formation of hydroxyapatite films on titanium pretreated with etidronic acid
Authors: Gao F. , Sherwood Peter M. A.
Published: August 2012

X‐ray photoelectron spectroscopy in the core and valence band region was used to study the formation of hydroxyapatite films on the surface of titanium. The approach used achieves the adhesion of hydroxyapatite by the initial formation of a thin, mainly oxide‐free, etidronate film on the metal. In this approach, it was not possible to prepare hydroxyapatite films of any reasonable thickness on the titanium surface without prior treatment with etidronic acid. Because hydroxyapatite is a principal component of teeth and bones, it is likely that the coated metals will have desirable biocompatible properties. The hydroxyapatite film showed no changes when the film was exposed to air, water, and 1 m sodium chloride solution as representative components of the environment of the film in the human body. These films formed on titanium may find application in medical implants. The thin hydroxyapatite and etidronate film on the metal show differential charging effects that caused a doubling of some of the spectral features. Copyright © 2012 John Wiley & Sons, Ltd.
Fabrication of Novel Hierarchical Structured Fe3O4@LnPO4 (Ln=Eu, Tb, Er) Multifunctional Microspheres for Capturing and Labeling Phosphopeptides
Authors: Wang Zhi‐Gang , Cheng Gong , Liu Yan‐Lin , Zhang Ji‐Lin , Sun De‐Hui , Ni Jia‐Zuan
Published: August 2012

Novel core–shell structured Fe3O4@LnPO4 (Ln=Eu, Tb, Er) multifunctional microspheres with a magnetic Fe3O4 core and a LnPO4 shell covered with spikes are synthesized for the first time through the combination of a homogeneous precipitation approach and an ion‐exchange process. Their potential for selective capture, rapid separation, and easy mass spectrometry (MS) labeling of the phosphopeptides from complex proteolytic digests are evaluated. These affinity microspheres can improve the specificity for capture of the phosphopeptides, realize fast magnetic separation, enhance the MS detection signals, and directly identify phosphopeptides through 80 Da mass loss in the mass spectra. The synthesis strategy could become a general and effective technique for similar core–shell hierarchical structures.
Strain Rate Sensitivity of Pre‐Strained AISI 301LN2B Metastable Austenitic Stainless Steel
Authors: Larour Patrick , Verleysen Patricia , Dahmen Kirsten , Bleck Wolfgang
Published: August 2012

The dynamic behavior of AISI 301LN2B (EN 1.4318) metastable austenitic steel grade has been investigated at 296 K by means of servohydraulic tensile and split Hopkinson bar testing in the strain rate range 0.005–1000 s−1. As delivered, as well as 10% uniaxial, biaxial, and plane strain pre‐strained conditions, without subsequent heat treatment have been tested. A negative strain rate sensitivity is observed in the low strain rate range between 10−4 and 1–10 s−1. Pre‐straining reduces the magnitude of the adiabatic tensile strength softening, especially in the plane strain condition with higher triaxility. The thermal activation related dynamic flow stress increase is not dependent on pre‐straining. The γ → α′ induced additional flow stress increase, however, is highly strain rate and pre‐straining sensitive. The amount of pre‐straining determines the overall ductility at fracture, and therefore the adiabatic temperature increase. The pre‐straining stress state influences the amount of α′‐martensite formed before dynamic testing, and consequently the maximum intensity of the TRIP induced flow stress increase by subsequent dynamic testing.
Synthesis, Structure, and Bonding Analysis of the Polar Intermetallic Phase Ca2Pt2Cd
Authors: Samal Saroj L. , Corbett John D.
Published: August 2012

The polar intermetallic phase Ca2Pt2Cd was discovered during explorations of the Ca‐Pt‐Cd system. The compound was synthesized by high temperature reactions, and its structure refined by single‐crystal X‐ray diffraction as orthorhombic, Immm, a = 4.4514(5), b = 5.8415(6), c = 8.5976(9) Å, Z = 2. The structure formally contains infinite, planar networks of [Pt2Cd]4– along the ab plane, which can be described as tessellation of six and four‐member rings of the anions, with cations stuffed between the anion layers. The infinite condensed platinum chains show a substantial long–short distortion of 0.52 Å, an appreciable difference between Ca2Pt2Cd (26 valence electrons) and the isotypic but regular Ca2Cu2Ga (29 VE). The relatively large cation proportion diminishes the usual dominance of polar (Pt–Cd) and 5d–5d (Pt–Pt) contributions to the total Hamilton populations.
The Prolific {ZR6}X12R and {ZR6}X10 Structure Types with Isolated Endohedrally Stabilized (Z) Rare‐Earth Metal (R) Cluster Halide (X) Complexes
Authors: Rustige Christian , Brühmann Matthias , Steinberg Simon , Meyer Eva , Daub Kathrin , Zimmermann Sina , Wolberg Marike , Mudring Anja‐Verena , Meyer Gerd
Published: August 2012

Comproportionation reactions of rare‐earth metal trihalides, RX3, with the respective R metal in the presence of a transition metal Z, preferably from group 8 through 10, yielded single crystals of 31 {ZR6}X12R and 22 {ZR6}X10 type compounds, in most cases for the first time, especially with R = Tb, Dy, Ho, and Er. These are compared with literature entries. The crystal structures are discussed for the equal‐atom pair {IrEr6}I12Er and {IrEr6}I10. In both cases, {IrEr6}Ii12Ia6 cluster complexes are connected via i‐i and i‐a/a‐i bridges, respectively, the {IrEr6} clusters are isolated. Band structure calculations were carried out on the LMTO‐ASA level for a number of {ZY6}X10 examples; the density of states (DOS) and Crystal Orbital Hamiltonian Populations (COHP) derived therefrom exhibit strong Z–Y and Y–X bonding interactions. Most profitable are X = I and endohedral elements of sixth period atoms, especially Z = Os, Ir.
Koordinationspolymere mit Tris(4‐carboxyphenyl)‐phosphanoxid als Ligand – Synthese, Kristallstrukturen und topologische Untersuchungen
Authors: Schmiedel Peter , Krautscheid Harald
Published: August 2012

The solvothermal reaction of MnCl2·4H2O or CoCl2·6H2O with tris(4‐carboxyphenyl)‐phosphine oxide (H3TPO), in DMF orDMA resulted in the four coordination polymers [M3(tpo)2(dmf)(H2O)2](1: M = Mn; 2: M = Co), (NMe2H2)[Mn3Cl(HCO2)(htpo)(tpo)(H2O)] (3) and (NMe2H2)[Mn3(tpo)2(OAc)] (4). Structural characterization by X‐ray crystallography revealed that 1–4 form 3‐periodical infinite networks; after synthesis solvent molecules occupy the framework pores. The topologies of the networks in 1, 2 and 3 are unprecedented in literature and are systematically characterized. Furthermore, these topologies could be derived from hexagonal close packing (1, 2) and cubic close packing (3), respectively.Compounds 1, 2 and 4 were synthesized as pure crystalline materials, their thermal behaviour was examined by TG/DTA measurements and temperature dependent PXRD. 1, 2 and 4 show remarkable thermal stability with decomposition temperatures between 450 and 500 °C. Temperature dependent PXRD measurements of compounds 1 and 2 reveal a structural transition at 260 °C, framework 4 loses its crystallinity at 210 °C.
GeCpbig2 [Cpbig = C5(CH2C6H4‐iPr)5]: A Flexible Sandwich Molecule
Authors: Naglav Dominik , Tobey Briac , Harder Sjoerd , Schnepf Andreas
Published: August 2012

GeCpbig2 (1) [Cpbig = C5(CH2C6H4‐iPr)5] was synthesized by a reaction of KCpbig either with a GeCl solution or GeCl2 and was obtained as colorless crystals. The molecular structure of 1 was determined by X‐ray diffraction, showing that 1 features two pentahapto bonded Cpbig ligands in a bent configuration with a Cpbig‐Ge–Cpbig angle of 161°. Two out of ten benzyl substituents point towards the lone pair at the germanium atom so that two molecules fit perfectly together, leading to a dimeric arrangement of 1 within the solid state. Two polymorphs of 1 could be isolated, where 1 is oriented in a different way. As indicated by quantum chemical calculations, the open structure, where all benzyl substituents point away from the germanium atom is only disfavored by 21.6 kJ·mol–1. In the open structure a bent arrangement is still realized, giving access to the lone pair at the germanium atom for further applications, e.g. in coordination chemistry.
Self‐Intercalation and Vacancy‐Ordering in 6R‐CuxTa1+yS2 (x ≈ 0.23, y = 0, 0.06)
Authors: Ali Sk Imran , Mondal Swastik , Prathapa Siriyara Jagannatha , van Smaalen Sander , Zörb Steffen , Harbrecht Bernd
Published: August 2012

The eightfold 2a0×2b0×2c0 superstructures of 6R‐CuxTa1+yS2 are reported for crystal A with x = 0.237 and y = 0, and crystal B with x = 0.23 and y = 0.06. Compelling evidence is presented for the self‐intercalation of tantalum onto octahedral sites, based on the diffraction data and crystal chemical arguments. The eightfold superstructure is formed by partial vacancy ordering within planes of intercalated atoms, while the stacking of TaS2 layers remains that of the 6R polytype. Temperature‐dependent X‐ray diffraction experiments show that the superstructure exists between T = 14 K and at least 370 K. Intercalated atoms enter the compound at octahedral and tetrahedral sites in alternating Van der Waals gaps. Intercalation is inhomogeneous, with average occupancies varying between 0.11 for octahedral sites within one Van der Waals gap and 0.23 for the tetrahedral sites within another Van der Waals gap. It is proposed that partial vacancy ordering is governed by the principle of maximum separation between intercalated atoms.
Novel therapeutic target for cancer stem cells in hepatocellular carcinoma
Authors: Nagano Hiroaki , Ishii Hideshi , Marubashi Shigeru , Haraguchi Naotsugu , Eguchi Hidetoshi , Doki Yuichiro , Mori Masaki
Published: August 2012

Cancer is a disease of genetic and epigenetic alterations, which are emphasized as the central mechanisms of tumor progression in the multi‐stepwise model. Discovery of rare subpopulations of cancer stem cells (CSCs) has created a new focus in cancer research. The heterogeneity of tumors can be explained with the help of CSCs supported by anti‐apoptotic signaling. CSCs mimic normal adult stem cells by demonstrating unique characteristics of self‐renewal and pluripotency, and the critical role for tumor growth and resistance to anti‐cancer therapy. We found that CD13 was a surface marker for CSCs in human liver cancer cell lines and clinical samples, and that CD13+ CSCs were associated with a hypoxic marker in clinical hepatocellular carcinoma (HCC) sample, suggesting that CD13+ CSCs have the critical role in tumor growth and resistance to anti‐cancer therapy in liver cancers. In this review article, we update recent findings regarding the involvement of CSCs, especially in HCC.
Glucokinase contributes to glucose phosphorylation in d-lactic acid production by Sporolactobacillus inulinus Y2-8
Authors: Zheng Lu , Bai Zhongzhong , Xu Tingting , He Bingfang
Published: August 2012

Sporolactobacillus inulinus, a homofermentative lactic acid bacterium, is a species capable of efficient industrial d-lactic acid production from glucose. Glucose phosphorylation is the key step of glucose metabolism, and fine-tuned expression of which can improve d-lactic acid production. During growth on high-concentration glucose, a fast induction of high glucokinase (GLK) activity was observed, and paralleled the patterns of glucose consumption and d-lactic acid accumulation, while phosphoenolpyruvate phosphotransferase system (PTS) activity was completely repressed. The transmembrane proton gradient of 1.3–1.5 units was expected to generate a large proton motive force to the uptake of glucose. This suggests that the GLK pathway is the major route for glucose utilization, with the uptake of glucose through PTS-independent transport systems and phosphorylation of glucose by GLK in S. inulinus  d-lactic acid production. The gene encoding GLK was cloned from S. inulinus and expressed in Escherichia coli. The amino acid sequence revealed significant similarity to GLK sequences from Bacillaceae. The recombinant GLK was purified and shown to be a homodimer with a subunit molecular mass of 34.5 kDa. Strikingly, it demonstrated an unusual broad substrate specificity, catalyzing phosphorylation of 2-deoxyglucose, mannitol, maltose, galactose and glucosamine, in addition to glucose. This report documented the key step concerning glucose phosphorylation of S. inulinus, which will help to understand the regulation of glucose metabolism and d-lactic acid production.
Construction and application of an Escherichia coli bioreporter for aniline and chloroaniline detection
Authors: Vangnai Alisa S , Kataoka Naoya , Soonglerdsongpha Suwat , Kalambaheti Chatvalee , Tajima Takahisa , Kato Junichi
Published: August 2012

Aniline and chlorinated anilines (CAs) are classified as priority pollutants; therefore, an effective method for detection and monitoring is required. In this study, a green-fluorescence protein-based bioreporter for the detection of aniline and CAs was constructed in Escherichia coli DH5α, characterized and tested with soil and wastewater. The sensing capability relied on the regulatory control between a two-component regulatory protein, TodS/TodT, and the PtodX promoter of Pseudomonas putida T-57 (PpT57), since the gene expression of todS, todT, and todC2 are positively induced with 4-chloroaniline. The bioreporter system (DH5α/pPXGFP–pTODST) is markedly unique with the two co-existing plasmids. The inducibility of the fluorescence response was culture-medium- and time-dependent. Cells grown in M9G medium exhibited a low background fluorescence level and were readily induced by 4CA after 3-h exposure, reaching the maximum induction level at 9 h. When tested with benzene, toluene, ethyl-benzene and xylene, aniline and CAs, the response data were best fit by a sigmoidal dose–response relationship, from which the K  1/2 value was determined for the positive effectors. 3CA and 4CA were relatively powerful inducers, while some poly-chlorinated anilines could also induce green fluorescence protein expression. The results indicated a broader recognition range of PpT57’sTodST than previously reported for P. putida. The test results with environmental samples were reliable, indicating the potential application of this bioreporter in the ecotoxicology assessment and bioremediation of areas contaminated with aniline- and/or CAs.
Full‐Spectrum Parenting
Authors: Schuler Lou
Published: August 2012

A parent of two teenagers diagnosed with Asperger's Syndrome describes daily life with them and their neurotypical sibling.
The Road Less Traveled: One Genetic Counselor's Reflections on Disability and the Genetic Counseling Profession
Authors: Lenihan Melissa
Published: August 2012

Reflections on disability and the genetic counseling profession from the perspective of a seasoned genetic counselor who is also the mom of a child with a disability.
Genetic Analysis of Disheveled 2 and Disheveled 3 in Human Neural Tube Defects
Authors: De Marco Patrizia , Merello Elisa , Consales Alessandro , Piatelli Gianluca , Cama Armando , Kibar Zoha , Capra Valeria
Published: August 2012

Neural tube defects are severe malformations affecting 1/1,000 live births. The planar cell polarity pathway controls the neural tube closure and has been implicated in the pathogenesis of neural tube defects both in animal models and human cohorts. In mouse disruption ofDvl2alone (Dvl2−/−) orDvl2andDvl3(Dvl2−/−;Dvl3+/−,Dvl2+/−;Dvl3−/−) results in incomplete neurulation, suggesting a role for Disheveled in neural tube closure. Disheveled is a multifunctional protein that is involved in both the canonical Wnt signaling and the noncanonical planar cell polarity pathway. In this study, we analyzed the role of the human orthologsDVL2andDVL3in a cohort of 473 patients with neural tube defects. Rare variants were genotyped in 639 ethnically matched controls. We identified seven rare missense mutations that were absent in all controls analyzed. Two of these mutations, p.Tyr667Cys and p.Ala53Val, identified inDVL2were predicted to be detrimental in silico. Significantly, a 1-bp insertion (c.1801_1802insG) in exon 15 ofDVL2predicted to lead to the truncation of the protein was identified in a patient with a complex form of caudal agenesis. In summary, we demonstrate a possible role for rare variants inDVL2gene as risk factors for neural tube defects.