bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Pulse Voltammetric Determination of Uric Acid on Carbon‐Coated Iron Nanoparticle Modified Glassy Carbon Electrodes
Authors: Wang Shengfu , Xu Qiao , Liu Guodong
Published: March 2008

A carbon‐coated iron nanoparticles (CIN, a new style fullerence related nanomaterial) modified glassy carbon electrode (CIN/GCE) has been developed for the determination of uric acid (UA). Electrochemical behaviors of UA on CIN/GCE were explored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the voltammetric response of UA on CIN/GC was enhanced dramatically because of the strong accumulation effect of CIN and the large working area of the CIN/GC electrode. The parameters including the pH of supporting electrolyte, accumulation potential and time, that govern the analytical performance of UA have been studied and optimized. The DPV signal of UA on CIN/GCE increased linearly with its concentration in the range from 5.0×10−7 to 2.0×10−5 M, with a detection limit of 1.5×10−7 M (S/N=3). The CIN/GCE was used for the determination of UA in samples with satisfactory results. The proposed CIN/GCE electrochemical sensing platform holds great promise for simple, rapid, and accurate detection of UA.
Patterns of cerebral activation during olfactory and trigeminal stimulations
Authors: Lombion Sandrine , Comte Alexandre , Tatu Laurent , Brand Gérard , Moulin Thierry , Millot Jean‐Louis
Published: March 2008

It is well known that most odorants stimulate both the olfactory system and the trigeminal system. However, the overlap between the brain processes involved in each of these sensorial perceptions is still poorly documented. This study aims to compare fMRI brain activations while smelling two odorants of a similar perceived intensity and pleasantness: phenyl ethyl alcohol (a pure olfactory stimulus) and iso‐amyl‐acetate (a bimodal olfactory‐trigeminal stimulus) in a homogeneous sample of 15 healthy, right‐handed female subjects. The analysis deals with the contrasts of brain activation patterns between these two odorant conditions. The results showed a significant recruitment of the right insular cortex, and bilaterally in the cingulate in response to the trigeminal component. These findings are discussed in relation to the characteristics of these odorants compared with those tested in previous studies. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Cell autonomous function of nogo and reticulons: The emerging story at the endoplasmic reticulum
Authors: Teng Felicia Yu Hsuan , Tang Bor Luen
Published: March 2008

The myelin‐associated membrane protein reticulon‐4 (RTN4)/Nogo has been extensively studied with regards to its neurite outgrowth inhibitory function, both in limiting plasticity in the healthy adult brain and regeneration during central nervous system injury. These activities are presumably associated with Nogo splice isoforms expressed on the cell surface and function largely in trans, exerting an influence as an intercellular membrane‐bound ligand. Nogo, and other reticulon paralogues and orthologues, are however mainly localized to the endoplasmic reticulum (ER), and are likely to have cell autonomous functions that are not yet clear. Emerging evidence suggests that Nogo may have a role in modulating the morphology and functions of the ER. This role is apparently not essential for cell viability under normal growth conditions, but may be manifested under certain stress conditions. J. Cell. Physiol. 216: 303–308, 2008. © 2008 Wiley‐Liss, Inc.
Developing and testing a measure for the ethical culture of organizations: the corporate ethical virtues model
Authors: Kaptein Muel
Published: March 2008

Based on four interlocking empirical studies, this paper initially validates and refines the Corporate Ethical Virtues Model which formulates normative criteria for the ethical culture of organizations. The findings of an exploratory factor analysis provide support for the existence of eight unidimensional subscales: clarity, congruency of supervisors, congruency of management, feasibility, supportability, transparency, discussability, and sanctionability. The findings of a confirmatory factor analysis show that the overall fit of the model is quite high. Evidence of convergent and discriminant validity is also found. The resulting 58‐item self‐reporting questionnaire is a useful tool that can be used in future research and by managers in assessing the ethical culture of their organization. Copyright © 2008 John Wiley & Sons, Ltd.
Character in organizational research: past directions and future prospects
Authors: Wright Thomas A. , Huang Ching‐Chu
Published: March 2008

Character (ethos) refers to those interpenetrable habitual qualities within individuals, and applicable to organizations that both constrain and lead them to desire and pursue personal and societal good. In our Incubator article, we undertake two objectives. First, we provide our conceptualization of character; briefly specifying what character is and is not. Second, we introduce several promising directions for organizationally based research on character. Copyright © 2008 John Wiley & Sons, Ltd.
The effect of cold trap adsorbents on the gas chromatographic analysis of ambient VOCs under Peltier cooling conditions
Authors: Pal Raktim , Kim Ki‐Hyun
Published: March 2008

In this work, the relative analytical performance of the GC‐based detection method was investigated with a major focus on cold trap (CT) adsorbent materials against four aromatic volatile organic compounds (VOCs) (e. g., benzene, toluene, xylene, and styrene). A series of calibration experiments were hence conducted under cryofocusing conditions formed by the Peltier cooling system in a thermal desorber (TD) unit. During the course of this study, comparative calibration datasets were acquired for each of the three CT types: (i) CT (I) = Carbopack B + Carbopack C, (ii) CT (II) = Carbopack B + Carboxen 1000, and (iii) CT (III) = Tenax TA. All calibration datasets were obtained under subambient temperature (–10°C) conditions controlled by the Peltier cooling system. The reliability of the calibration data was also assessed in an ancillary experiment with the aid of the modified injection through a thermal desorber (MITD) method. The results demonstrated that the GC detection properties of different VOCs were not altered significantly between different CT applications under Peltier conditions, although relative sensitivity could be distinguished moderately depending on the CT type.
Thermal dimerization kinetics of 3‐(p‐bromo‐phenyl)‐pyridazinium benzoyl methylid in solutions
Authors: Melnig V. , Humelnicu I. , Dorohoi D. O.
Published: March 2008

3‐(p‐Bromo‐phenyl)‐pyridazinium‐benzoyl methylid (BPPBM) participates in solution at 3 + 3 dipolar thermal dimerization that can be spectrally monitored by the extinction in its visible intramolecular charge transfer (ICT) band. The attenuation of ICT band intensity shows the decrease of the BPPBM concentration with the increasing of dimer concentration. The complex kinetics of light‐assisted dimerization process was studied taking into account that the thermodynamic equilibrium is reached after more than 24 h. On the basis of general order of reaction theory, we found that the dimerization reaction must be described as a multistep mechanism. The rate constants of the dimerization reactions in ethanol (k = 0.00897 s−1) and benzene (k = 0.00774 s−1) solutions were correlated with the BPPBM and dimer structural features established by using the HyperChem 5.02 simulation program package. A kinetic mechanism of 3 + 3 dipolar thermal dimerization for the studied ylid is proposed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 230–239, 2008
Temperature‐dependent kinetics study of the gas‐phase reactions of atomic chlorine with acetone, 2‐butanone, and 3‐pentanone
Authors: Zhao Z. , Huskey D. T. , Nicovich J. M. , Wine P. H.
Published: March 2008

A laser flash photolysis–resonance fluorescence technique has been employed to study the kinetics of the reactions of atomic chlorine with acetone (CH3C(O)CH3; k1), 2‐butanone (C2H5C(O)CH3; k2), and 3‐pentanone (C2H5C(O)C2H5; k3) as a function of temperature (210–440 K) and pressure (30–300 Torr N2). No significant pressure dependence is observed for any of the reactions studied. Arrhenius expressions (units are 10−11 cm3 molecule−1 s−1) obtained from the data are k1(T) = (1.53 ± 0.19) exp[(−594 ± 33)/T], k2(T) = (2.77 ± 0.33) exp[(+76 ± 33)/T], and k3(T) = (5.66 ± 0.41) exp[(+87 ± 22)/T], where uncertainties are 2σ and represent precision only. The accuracy of reported rate coefficients is estimated to be ±15% over the entire range of pressure and temperature investigated. The room temperature rate coefficients reported in this study are in good agreement with a majority of literature values. However, the activation energies reported in this study are in poor agreement with the literature values, particularly for 2‐butanone and 3‐pentanone. Possible explanations for discrepancies in published kinetic parameters are proposed, and the potential role of Cl + ketone reactions in atmospheric chemistry is discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 259–267, 2008
On the 𝔉‐hypercentre of a finite group
Authors: Ballester–Bolinches Adolfo , Soler–Escrivà Xaro
Published: March 2008

The main objective of this paper is to study and describe the hypercentre of a finite group associated with saturated formations, in terms of some subgroup embedding properties related to permutability. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of standing waves for nonlinear defocusing fourth‐order dispersive Schrödinger equation with unbounded potentials
Authors: Chen Guanggan , Zhang Jian , Wei Yunyun
Published: March 2008

This paper is concerned with a nonlinear defocusing fourth‐order dispersive Schrödinger equation with unbounded potentials which models propagation in fiber arrays. We analyze the global existence of the solution and also obtain the existence of the standing waves for the system. Furthermore, we prove that the standing waves are orbitally stable. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence of global solutions for a three‐species predator‐prey model with cross‐diffusion
Authors: Pang P. Y. H. , Wang M. X.
Published: March 2008

In this short note, we study a strongly coupled system of partial differential equations which models the dynamics of a two‐predator‐one‐prey ecosystem in which the prey exercises defense switching and the predators collaboratively take advantage of the prey's strategy. We prove the existence of global strong solutions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supersingularity from group actions
Authors: Re Riccardo
Published: March 2008

I give a sufficient condition for the action of a group on an algebraic curve defined over in order that a good reduction of the curve to positive characteristic be a supersingular curve. I apply such criterion to abelian coverings of ℙ1 ramified over three points. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A problem of D. H. Lehmer and its mean value
Authors: Xu Zhefeng , Zhang Wenpeng
Published: March 2008

Let p be an odd prime and let a be an integer coprime to p. Denote by N (a, p) the number of pairs of integers b, c with bc ≡ a (mod p), 1 ≤ b, c < p and with b, c having different parity. The main purpose of this paper is to deduce an asymptotic formula for (N (2sad, p) – 1/2 (p – 1)), and obtain some interesting results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identifying parameters controlling soil delayed behaviour from laboratory and in situ pressuremeter testing
Authors: Yin Zhen‐Yu , Hicher Pierre‐Yves
Published: March 2008

The aim of this paper is to present a methodology for identifying the soil parameters controlling the delayed behaviour from laboratory and in situ pressuremeter tests by using an elasto‐viscoplastic model (EVP‐MCC) based on Perzyna's overstress theory and on the elasto‐plastic Modified Cam Clay model. The influence of both the model parameters and the soil permeability was studied under the loading condition of pressuremeter tests by coupling the proposed model equations with Biot's consolidation theory. On the basis of the parametric study, a methodology for identifying model parameters and soil permeability by inverse analysis from three levels of constant strain rate pressuremeter tests was then proposed and applied on tests performed on natural Saint‐Herblain clay. The methodology was validated by comparing the optimized values of soil parameters and the values of the same parameters obtained from laboratory test results, and also by using the identified parameters to simulate other tests on the same samples. The analysis of the drainage condition and the strain rate effect during a pressuremeter test demonstrated the coupled influence of consolidation and viscous effects on the test results. The numerical results also showed that the inverse analysis procedure could successfully determine the parameters controlling the time‐dependent soil behaviour. Copyright © 2008 John Wiley & Sons, Ltd.
Postnatal management and outcome of prenatally diagnosed lung lesions
Authors: Laje Pablo , Liechty Kenneth W.
Published: March 2008

Advancements in fetal diagnostic imaging have increased prenatal diagnosis of many fetal anomalies. The purpose of this chapter is to review the etiology and natural history of prenatally diagnosed cystic lung lesions, including congenital cystic adenomatoid malformations (CCAM), pulmonary sequestrations (PSs), hybrid lesions, and bronchogenic cysts, and then discuss current concepts in the management and outcome of these lesions. Copyright © 2008 John Wiley & Sons, Ltd.
Surveillance of suspected adverse reactions to natural health products in Italy
Authors: Menniti‐Ippolito Francesca , Mazzanti Gabriela , Santuccio Carmela , Angela Moro Paola , Calapai Gioacchino , Firenzuoli Fabio , Valeri Andrea , Raschetti Roberto
Published: March 2008

Purpose

Natural health products are promoted to the public as equally or more effective and less toxic than conventional drugs. However, some ‘natural’ medicines, and in particular some herbal medicines, are known to have adverse effects. The Italian Pharmacovigilance System, in charge of the Italian Medicines Agency, collects spontaneous reports only for registered drugs. The awareness of the need of surveillance of the safety of natural health products has stimulated the implementation of a suspected adverse reaction reporting system in Italy. The system has been set up by the Italian National Institute of Health.

Methods

An ad hoc reporting form can be downloaded from different institutional web sites. Voluntary reports of suspected adverse reactions are sent to the National Institute of Health and are evaluated by a multidisciplinary group of experts.

Results

From April 2002 to March 2007, 233 spontaneous reports of suspected adverse reactions to natural health products were collected. A large proportion of suspected adverse reactions were serious: hospitalization was reported in 35% of forms; 6% reported life threatening clinical events and two fatal events were notified. About 50% of suspected adverse reactions were related to gastrointestinal, skin, psychiatric and nervous system disorders. Mainly herbal products (66%) were involved. Twenty‐one cases of hepatitis of various seriousness were reported. Twenty‐one reports were associated with 27 homeopathic preparations, mostly preparations containing mixtures of substances. Fourteen reports regarded suspected reactions to products containing propolis.

Conclusion

Safety and efficacy of ‘natural’ medicines have not been thoroughly investigated. It is important to improve communication with the public on safety issues. Encouraging spontaneous reporting can contribute to improve awareness among health personnel and patients about the benefit–harm profile of these remedies. Copyright © 2008 John Wiley & Sons, Ltd.
Replicated studies of two randomized trials of angiotensin‐ converting enzyme inhibitors: further empiric validation of the ‘prior event rate ratio’ to adjust for unmeasured confounding by indication
Authors: Tannen Richard L. , Weiner Mark G. , Xie Dawei
Published: March 2008

Purpose

Using data from the United Kingdom General Practice Research Database (GPRD) randomized controlled trials (RCTs) were replicated to determine whether identifiable study characteristics and/or analytic methods influence the validity of observational studies.

Methods

This study reports GPRD replications of 2 RCTs that investigated whether angiotensin‐converting enzyme inhibitors (ACEIs) improve cardiovascular outcomes in patients without congestive heart failure at high risk for cardiovascular disease (heart outcomes prevention evaluation (HOPE) and EUROPA). The GPRD studies replicated to the extent feasible all aspects of these RCTs except for randomization.

Results

With adjustment for confounders using conventional biostatistical techniques, both GPRD studies exhibited results divergent from the RCTs. Myocardial infarction, stroke, congestive heart failure, and coronary revascularization were increased in the Exposed group of both GPRD studies; whereas these outcomes either were decreased or unchanged by ACEI therapy in both RCTs. The results also were analyzed with a new method that appears to adjust for both identified and unmeasured confounders. With this methodology that employs the ratio of event rates between the Exposed and Unexposed cohorts prior to study start time to adjust the study hazard ratio (HR), the GPRD results for myocardial infarction, stroke, and coronary revascularization were largely similar to those found in the two RCTs.

Conclusions

This study provides additional empiric evidence suggesting that this new analytic methodology, ‘prior events rate ratio (PERR)’ adjustment, is a promising solution for the vexing problem of ‘unmeasured confounding’ in observational studies. Additional statistical simulations are needed to fully appreciate the applicability and limitations of this method. Copyright © 2008 John Wiley & Sons, Ltd.
Replication of the Scandinavian Simvastatin Survival Study using a primary care medical record database prompted exploration of a new method to address unmeasured confounding
Authors: Weiner Mark G. , Xie Dawei , Tannen Richard L.
Published: March 2008

Purpose

To examine whether identifiable study characteristics and/or analytic methods used determine observational study validity, as assessed by replicating randomized controlled trials using observational data.

Methods

A cohort from the United Kingdom General Practice Research Database (GPRD) was used to replicate the Scandinavian Simvastatin Survival Study RCT, which investigated statin treatment of hypercholesterolemic subjects with coronary heart disease. All aspects of the RCT except randomization were replicated to the extent possible in the GPRD study, which included 2,871 Unexposed and 1,280 statin‐treated Exposed subjects.

Results

Overall mortality [adjusted hazard ratio 0.71 (0.53–0.96)] and myocardial infarction [adjusted HR 0.79 (0.61–1.02)] decreased in the GPRD study similar to the RCT. Coronary revascularization increased two‐fold in the GPRD study, whereas it decreased significantly in the RCT [0.63 (0.54–0.74)]. This latter disparity prompted use of a new methodology to adjust for unmeasured confounding, which yielded an adjusted HR [1.0 (0.75–1.33)] more comparable to the RCT.

Conclusions

This study provides additional evidence that a replicated GPRD observational study can yield results reasonably similar to a RCT. More important, it provides preliminary evidence suggesting that a new analytic methodology may adjust for unmeasured confounding, the major limitation to research using observational data. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of tribological behaviour and biocompatibility of Ti6Al4V alloy after ion implantation or thermal oxidation
Authors: Díaz C. , Lutz J. , Mändl S. , García J. A. , Martínez R. , Rodríguez R. J. , Damborenea J. J. , Arenas M. A. , Conde A.
Published: March 2008

This paper describes improvements of the tribological properties and the biocompatibility of Ti6Al4V alloy implanted by oxygen plasma immersion (PIII) in comparison with other treatments like thermal oxidation, conventional beamline ion implantation (II) of nitrogen and a combination of both thermal oxidation and II of nitrogen.

Ball‐on‐disc friction and wear tests were performed to investigate the modifications introduced for each treatment. Biocompatibility tests were carried out by controlling Al and V ion migration in a Hank's solution simulating the human body fluid. The reported results indicate that PIII provide a promising method to improve the characteristics of the Ti6Al4V alloy to be used in human body implants. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficiency of a Venetian blind filter in PBIID
Authors: Schirmer Sabine , Manova Darina , Mändl Stephan
Published: March 2008

Plasma Based Ion Implantation and Deposition (PBIID) is a preferred method for obtaining high‐quality, defect‐free coatings with excellent adhesion properties. However, a major drawback is the generation of unwanted macroparticles with a diameter between 1 and 25 µm at the cathode of the vacuum arc used to produce the metal ions. A Venetian blind filter with louvers oriented at a defined angle towards plasma can be used to improve the quality of these thin films. Film quality effects were complex, depending on cathode material, gaas fill pressure, gas fill species and louvre angle. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Predicted depth profiles for nitrogen‐ion implantation into gallium arsenide
Authors: Risch M. , Bradley M.
Published: March 2008

We present a new method to predict the spatial variation of the band gap in nitrogen‐implanted gallium arsenide. Band gap engineering of a GaAsN alloy was employed to design an emission peak at 1.3 µm. Based on SRIM simulations, we propose a concentration of 6% N in GaAs at the plateau of the trapezoidal depth profile for the desired band gap. The depth profile could be manufactured by virtue of subsequent high voltage pulses. Software based on the Lieberman model was developed to predict fluences from measurements of a simple Langmuir probe and the time dependent electrode potential. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light source inner surface changes depending on treatment
Authors: Skudra A. , Zorina N. , Gavare Z. , Berzins M. , Erts D.
Published: March 2008

Our work is connected with the preparation of different type of electrodeless discharge lamps. In this work we investigate the influence of the SiO2 glass wall treatment procedures on the inner surface of the electrodeless lamps. Three different treatment procedures were applied: vacuum cleaning, vacuum‐thermal cleaning and training in the high frequency discharge. The surface modification has been investigated by means of atomic force microscopy. Substantial changes of the SiO2 glass surface have been observed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PI3D processing of DLC coatings for different applications
Authors: Nikiforov S. A. , Ryoo H. J. , Oh H. S. , Rim G. H.
Published: March 2008

DLC (a ‐C:H) and Si‐DLC coatings have been deposited on various materials (steel, aluminium, silicon, glass, polymers) using a 1‐m3 interior‐antenna ICP PI3D facility with HMDSO and toluene as precursors. For conformal treatment of 3‐D workpiececs, a low‐voltage (0.5 ‐ 1) kV, high repetition rate (up to 70 kHz) pulsing was applied. However, DLC formation on dielectric substrates was performed at higher (2 ‐ 10) kV voltage using short (1 ‐ 1.5) μs pulses to minimize surface charging. Coating adhesion was achieved by formation of multi layer structure comprising Si‐containing buffer layer, transient layer, DLC layer with gradually increasing hardness, and top hard DLC. Film hardness was (5 ‐ 20) GPa, and the deposition rate (4 ‐ 0.5) μm/h. DLC surface roughness was (0.7 ‐ 60) nm and water contact angle 70° ‐ 110° depending on process parameters which implies various applications. Batch processing of sliding parts, cutting tools, glass moulds was performed. Double‐side DLC coating on polymer web eliminated its rolling up due to the coating stress. With novel ICP antenna the DLC processing is promising for large‐scale nano pattern transfer technology. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly localized ion focusing effects in PBIID
Authors: Haberkorn Frank , Todorova Dessislava , Manova Darina , Mändl Stephan
Published: March 2008

Plasma Based Ion Implantation and Deposition (PBIID) is characterized by a complex interaction of a supersonic plasma flux, a plasma sheath expanding and receding on a timescale of microseconds and a substrate which can be of an arbitrary complex shape. It is shown that ions impinging on the substrate in the wake region consist of two groups with strongly differing incidence angles. At the same time, localized ion focusing is observed only for very long pulses of 50 µs and intermediate voltages of 2.5 – 3.5 kV, independent of the cathode material – Ti or Al – and the Ar background pressure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of chemical binding states between ultra shallow plasma doping (PD) and ion implantation (I/I) samples by using hard X‐ray photoelectron spectroscopy (HX‐PES)
Authors: Jin C. G. , Kobata M. , Sasaki Y. , Okashita K. , Nakamoto K. , Mizuno B. , Ikenaga E. , Kobayashi K.
Published: March 2008

We measured HX‐PES (Si 1s) of ultra low energy ion implantion (I/I) samples combined with Ge pre‐amorphizaiton ion implantation (Ge‐PAI) before and after spike RTA, and compared it with that of plasma doping (PD) samples. As‐doped I/I sample showed higher hole density compared to as‐doped PD sample due to lower defect induced carrier trap. Ge‐PAI+I/I sample showed strong asymmetric in lower binding energy region due to Si‐Ge bonding. After spike RTA, PD sample showed superior impurity activation than that of Ge‐PAI+I/I sample. Both Ge‐PAI+I/I and PD sample showed excellent recrystallization after spike RTA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion internal energy distributions validate the charge residue model for small molecule ion formation by spray methods
Authors: Touboul David , Jecklin Matthias Conradin , Zenobi Renato
Published: March 2008

This paper reports a detailed study of the internal energy distribution of ions formed by four electrospray ionization (ESI)‐related ionization methods, with particular emphasis on electrosonic spray ionization (ESSI). Substituted benzylpyridinium ions were used as thermometer ions to probe the internal energy distribution. The influence of different instrumental parameters was studied. Cone and skimmer voltages as well as the collision energy were found to strongly affect the ion internal energy distribution, whereas the distance between the emitter and the inlet of the mass spectrometer, the nebulizing gas pressure or the flow rate showed no influence. The internal energy distribution obtained with an ESSI source was compared with those obtained for electrospray (ESI), nanoelectrospray (nanoESI) and sonic spray ionization (SSI) on the same mass spectrometer with the same instrumental parameters. No clear differences were observed. As the charge residue model is the only ion formation mechanism possible for SSI, we conclude that benzylpyridinium ions are formed by the pathway suggested by this model. Copyright © 2008 John Wiley & Sons, Ltd.
Differentiation between isomeric triantennary N‐linked glycans by negative ion tandem mass spectrometry and confirmation of glycans containing galactose attached to the bisecting (β1‐4‐GlcNAc) residue in N‐glycans from IgG
Authors: Harvey David J. , Crispin Max , Scanlan Chris , Singer Bernhard B. , Lucka Lothar , Chang Veronica T. , Radcliffe Catherine M. , Thobhani Smita , Yuen Chun‐Ting , Rudd Pauline M.
Published: March 2008

Negative ion tandem mass spectrometry (MS/MS) spectra of three isomeric triantennary N‐linked glycans provided clear differentiation between the isomers and confirmed the occurrence of an isomer that was substituted with galactose on a bisecting GlcNAc (1 → 4‐substituted on the core mannose) residue recently reported by Takegawa et al. from N‐glycans released from human immunoglobulin G (IgG). We extend this analysis of human serum IgG to reveal an analogue of the fucosylated triantennary glycan reported by Takegawa et al. together with a third compound that lacked both the sialic acid and the fucose residues. In addition, we demonstrate the biosynthesis of bisected hybrid‐type glycans with the galactose modification, with and without core fucose, on the stem cell marker glycoprotein, 19A, expressed in a partially ricin‐resistant human embryonic kidney cell line. It would appear, therefore, that this modification of N‐linked glycans containing a galactosylated bisecting GlcNAc residue may be more common than originally thought. Negative ion MS/MS analysis of glycans is likely to prove an invaluable tool in the analysis and monitoring of therapeutic glycoproteins. Copyright © 2008 John Wiley & Sons, Ltd.
A comparison of carbon and nitrogen stable isotope ratios of fish tissues following lipid extractions with non‐polar and traditional chloroform/methanol solvent systems
Authors: Logan John M. , Lutcavage Molly E.
Published: March 2008

Stable isotope ratios act as chemical tracers of animal diet, and are used to study food web dynamics. Because carbon stable isotope values are influenced by tissue lipid content, a number of extraction methods have been used to remove lipid bias, but, in some species and tissues, extractions also alter nitrogen isotope values. We have analyzed δ13C and δ15N in Atlantic bluefin tuna liver and white muscle, and whole Atlantic herring, fish tissues covering a wide range of lipid content (bulk C:N 3.1–12.5). In order to compare δ13C and δ15N values from traditional chloroform/methanol extractions with non‐polar solvent alternatives, we analyzed samples following (1) no treatment, (2) lipid removal using chloroform/methanol (2:1), and (3) Soxhlet extractions using chloroform, diethyl ether or hexane. Chloroform/methanol and chloroform extractions produced the lowest C:N values and highest δ13C values. In bluefin tuna, chloroform and hexane extractions significantly altered liver δ15N, and all methods significantly altered δ15N values in white muscle. Whole Atlantic herring δ15N was not altered by any extraction method, while the 2:1 chloroform/methanol extraction most completely removed fish tissue lipid components. Our results indicate that δ15N effects are not limited to common chloroform/methanol extractions and suggest that chloroform/methanol is the most effective extraction for δ13C correction. Given evidence for δ15N alteration among all tested methods, mathematical correction approaches should be further explored as an alternative to lipid correction. Copyright © 2008 John Wiley & Sons, Ltd.
High‐throughput, accurate mass liquid chromatography/tandem mass spectrometry on a quadrupole time‐of‐flight system as a ‘first‐line’ approach for metabolite identification studies
Authors: Tiller Philip R. , Yu Sean , Castro‐Perez Jose , Fillgrove Kerry L. , Baillie Thomas A.
Published: March 2008

Throughput for drug metabolite identification studies has been increased significantly by the combined use of accurate mass liquid chromatography/tandem mass spectrometry (LC/MS/MS) data on a quadrupole time‐of‐flight (QTOF) system and targeted data analysis procedures. Employed in concert, these tools have led to the implementation of a semi‐automated high‐throughput metabolite identification strategy that has been incorporated successfully into lead optimization efforts in drug discovery. The availability of elemental composition data on precursor and all fragment ions in each spectrum has greatly enhanced confidence in ion structure assignments, while computer‐based algorithms for defining sites of biotransformation based upon mass shifts of diagnostic fragment ions have facilitated identification of positions of metabolic transformation in drug candidates. Adoption of this technology as the ‘first‐line’ approach for in vitro metabolite profiling has resulted in the analysis of as many as 21 new chemical entities on one day from diverse structural classes and therapeutic programs. Copyright © 2008 John Wiley & Sons, Ltd.
A density functional study of the electric and magnetic properties of a benzene–transition‐metal multiple‐decker sandwich chain
Authors: Mahmudur Rahman M. , Muhida Rifki , Kasai Hideaki
Published: March 2008

We investigate the stability as well as the electric and magnetic properties of a benzene–transition‐metal multiple‐decker sandwich chain [M(C6H6)]∞ (M = ScNi). By performing first‐principles calculation based on the density functional theory, we find that the system [M(C6H6)]∞ is stable. We find that for the early transition‐metal atoms (ScMn) the binding energies are larger than those of the late transition metal atoms (FeNi), which is consistent with the experimental results. In case of electric properties, our investigations show that for the case of ScV, these are metallic, while for CrNi they are semiconducting. Copyright © 2008 John Wiley & Sons, Ltd.
Direct selection of Pichia pastoris expression strains using new G418 resistance vectors
Authors: Lin‐Cereghino Joan , Hashimoto Matthew D. , Moy Allison , Castelo James , Orazem Claire C. , Kuo Peter , Xiong See , Gandhi Vishal , Hatae Christopher T. , Chan Alex , Lin‐Cereghino Geoff P.
Published: March 2008

The methylotrophic yeast, Pichia pastoris, is widely used as a host organism for the expression of heterologous proteins. Currently, the Zeocin and blasticidin resistance genes are the only dominant selectable markers that can be used for primary selection of transformants. In this report we describe new expression vectors that can be used to select directly for P. pastoris transformants using G418 resistance conferred by a modified Tn903kanr gene. Compared to other dominant markers, this system is more economical and offers a higher transformation efficiency, due to the small sizes of the cloning vectors, pKAN B and pKANα B (GenBank Accession Nos EU285585 and EU285586, respectively). Additionally, multicopy transformants can be generated using these new vectors. Copyright © 2008 John Wiley & Sons, Ltd.
Bisimulations in calculi modelling membranes
Authors: Barbuti Roberto , Maggiolo-Schettini Andrea , Milazzo Paolo , Troina Angelo
Published: March 2008

Bisimulations are well-established behavioural equivalences that are widely used to study properties of computer science systems. Bisimulations assume the behaviour of systems to be described as labelled transition systems, and properties of a system can be verified by assessing its bisimilarity with a system one knows to enjoy those properties.

In this paper we show how semantics based on labelled transition systems and bisimulations can be defined for two formalisms for the description of biological systems, both capable of describing membrane interactions. These two formalisms are the Calculus of Looping Sequences (CLS) and Brane Calculi, and since they stem from two different approaches (rewrite systems and process calculi) bisimulation appears to be a good candidate as a general verification method.

We introduce CLS and define a labelled semantics and bisimulations for which we prove some congruence results. We show how bisimulations can be used to verify properties by way of two examples: the description of the regulation of lactose degradation in Escherichia coli and the description of the EGF signalling pathway. We recall the PEP calculus (the simplest of Brane Calculi) and its translation into CLS, we define a labelled semantics and some bisimulation congruences for PEP processes, and we prove that bisimilar PEP processes are translated into bisimilar CLS terms.
Researchers, Practitioners, and Funders: Using the Framework to Get Us on the Same Page
Authors: Emshoff James G.
Published: March 2008

The worlds of prevention research and practice are largely disconnected. The growing body of scientific knowledge regarding effects of prevention programs is not often disseminated and translated in a manner that leads to wide scale changes in practice. The Centers for Disease Control and Prevention, in collaboration with a team of academic researchers, has developed the Interactive Systems Framework for Dissemination and Implementation to help us understand the roles and interactions of those associated with developing knowledge, those associated with using the knowledge in practice settings, and those acting in the roles of bridge, support, and broker between the research and practice communities. This special issue on the Framework presents a variety of theoretical, practical and empirical issues related to this framework and its subsystems. This compilation of articles discuss the capacity of the Framework's subsystems, provide examples of the generally under‐developed prevention support system, describe the additional challenges involved in disseminating a change in culture, discuss the delicate balance and interaction of fidelity and adaptation, present a meta‐analysis of the relationships between program implementation and program outcomes, and include examples of how the Framework has been used to guide action. The present commentary on this special issue provides a critical examination of the contributions, implications, and challenges raised by each of these articles. It also includes a discussion of how the Framework relates to the basic values and practice of community psychology and concludes with some suggested future directions and challenges for the continued development and use of the Framework.
Does global warming induce segregation among alien and native beetle species in a mountain‐top?
Authors: Molina‐Montenegro Marco A. , Briones Raúl , Cavieres Lohengrin A.
Published: March 2008

The last few centuries have seen an increase in the mean air temperature of the planet, a phenomenon that is called “global warming”. One of the most sensitive habitats to the effects of global warming is the high‐elevation mountain environments, because these habitats are characterized by low temperature. Cushion plants are one of the best‐adapted growth forms in this habitat, generating more suitable sites for other plants and insects. In the present study, we experimentally evaluated the effects of global warming by open‐top chambers on the abundance and interaction of two ladybirds at 3,600 m, growing over cushions of the Azorella monantha species in the Andes of central Chile. Additionally, we measured variation in temperature, water content, and food availability by the presence of open‐top chambers as possible mechanisms of spatial segregation between ladybirds. Without open‐top chambers, the abundance of native and alien beetles was similar; but with open‐top chambers, the native beetle species is spatially segregated by alien species, decreasing in abundance. The open‐top chambers increase temperature and food availability, but not water content. We suggest that under the global warming scenario, the native insects will decrease in abundance or become extinct by the presence of alien insects, at least in the high‐elevation mountain environments.
Docosahexaenoic Acid is More Stable to Oxidation when Located at the sn‐2 Position of Triacylglycerol Compared to sn‐1(3)
Authors: Wijesundera Chakra , Ceccato Claudio , Watkins Peter , Fagan Peter , Fraser Benjamin , Thienthong Neeranat , Perlmutter Patrick
Published: March 2008

Regio‐isomeric effects on the oxidative stability of triacylglycerols (TAG) containing docosahexaenoic acid (DHA) were investigated using two pairs of regio‐isomerically pure TAG, namely 1,3‐dihexadecanoyl‐2‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (PDP)/1,2‐dihexadecanoyl‐3‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (PPD) and 1,3‐dioctadecenoyl‐2‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (ODO)/1,2‐dioctadecenoyl‐3‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (OOD) where P, O, and D represent palmitic acid, oleic acid, and DHA respectively. Each pair of regio‐isomers was subjected to accelerated auto‐oxidation (at 40 or 50 °C inside a dark oven). In each case, the TAG oxidized more slowly when DHA was located at the sn‐2 position (PDP and ODO) compared to the sn‐1(3) position (PPD and OOD), as evidenced by slower development of peroxide value, slower depletion of DHA, and slower generation of secondary oxidation products propanal and trans, trans‐2,4‐heptadienal. The positional effect on auto‐oxidation was more pronounced when DHA occurred in combination with oleic acid than with palmitic acid.
Paramphistomum daubneyi: production dynamics and infectivity of metacercariae originating from snails dissected at regular intervals
Authors: Vignoles P. , Rondelaud D. , Dreyfuss G.
Published: March 2008

Experimental infections of Galba truncatula with Paramphistomum daubneyi were carried out at 24°C to study the dynamics of larval development in snails dissected at regular intervals and to determine if metacercarial production might be improved. When the shell height of snails (4, 5, 6 or 7 mm) at exposure increased (experiment A), the total number of metacercariae was significantly higher in the 6- and 7-mm snails than in the other two groups, and the differentiation period was shortened (the first cercariae encysted at day 35 post-exposure (p.e.) instead of day 40 in the 4- and 5-mm groups). When the number of miracidia (two, three or five) for each 6-mm high G. truncatula increased (experiment B), a significant decrease of snail survival at day 30 p.e., a significant augmentation of prevalence, and a significant increase of metacercarial production were noted. In the two- and three-miracidium groups, the number of metacercariae was close to that found in the 6-mm snails from experiment 1, whereas they showed slower growth from day 45 to day 65 in the five-miracidium group. In the two groups of lambs infected with metacercariae encysted at days 45 or 60 p.e., no difference in the numbers of adult worms was noted. In contrast, in the case of 35-day encysted larvae, the number of adult worms was clearly lower. Snail dissection allowed higher metacercarial production, a saving of 12–15 days at 24°C to obtain these larvae, and a substantial decrease of their cost price for commercial production.
Rapid degradation of hypoxia‐inducible factor‐1α by KRH102053, a new activator of prolyl hydroxylase 2
Authors: Choi H J , Song B‐J , Gong Y‐D , Gwak W J , Soh Y
Published: March 2008

Background and purpose: Hypoxia‐inducible factor (HIF) is a transcription factor induced by hypoxia and degraded by ubiquitin‐dependent proteasomes in normoxic conditions. Under hypoxic conditions, hydroxylation of HIF‐1α subunit by prolyl hydroxylase (PHD) is suppressed, thus leading to increased levels of HIF. Although PHD2 plays a key role in regulating the levels of HIF, chemical activators of PHD2 are relatively unknown. The aim of this study was to identify small molecule activators of PHD2 that could be used, eventually, to suppress the level of HIF‐1α.

Experimental approach: By using the overproduced PHD2 as a target, a molecular library consisting of more than 600 small molecules with a benzopyran structure was screened with an HPLC assay method.

Key results: We found a potent activator of PHD2, KRH102053 (2‐amino‐4‐methylsulphanyl‐butylic acid‐4‐methoxy‐6‐(4‐methoxy‐benzylamino)‐2,2‐dimethyl‐chroman‐3‐yl ester). The effects of KRH102053 on controlling HIF were studied in human HOS osteosarcoma, rat PC12 phaeochromocytoma and human HepG2 hepatoma cells. Under our experimental conditions, KRH102053 decreased the protein level of HIF‐1α and the mRNA levels of HIF‐regulated downstream target genes, such as vascular endothelial growth factor, aldolase A, enolase 1 and monocarboxylate transporter 4. Consistent with these results, KRH102053 also inhibited the rates of HIF‐related migration and invasion of HOS cells as well as the degree of tube formation in human umbilical vein endothelium cells.

Conclusions and implications: These results suggest that KRH102053 and its structural analogues have the potential for use as therapeutic agents against various diseases associated with HIF.
Anti‐inflammatory effects of liquiritigenin as a consequence of the inhibition of NF‐κB‐dependent iNOS and proinflammatory cytokines production
Authors: Kim Y W , Zhao R J , Park S J , Lee J R , Cho I J , Yang C H , Kim S G , Kim S C
Published: March 2008

Background and purpose: Glycyrrhizae radix has been widely used as a cytoprotective, plant‐derived medicine. We have identified a flavanoid, liquiritigenin, as an active component in extracts of Glycyrrhizae radix. This research investigated the effects of liquiritigenin on the induction of inducible NOS (iNOS) and proinflammatory cytokines by lipopolysaccharide (LPS) in Raw264.7 cells, and on paw oedema in rats.

Experimental approach: iNOS expression was determined by western blotting, real‐time reverse transcription‐PCR and reporter gene analyses. Tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐1β and IL‐6 were assayed by ELISA. Gel shift assay and immunoblotting were used to assess NF‐κB activation. The effect of liquiritigenin on acute inflammation in vivo was evaluated using carrageenan‐induced paw oedema.

Key results: Treatment of Raw264.7 cells with liquiritigenin caused inhibition of LPS‐induced NF‐κB DNA binding activity, due to repression of I‐κBα phosphorylation and degradation. Liquiritigenin treatment prevented LPS from increasing the levels of iNOS protein and mRNA in a concentration‐dependent manner. Liquiritigenin also suppressed the production of TNF‐α, IL‐1β and IL‐6 from Raw264.7 cells after LPS. In rats, liquiritigenin treatment inhibited formation of paw oedema induced by carrageenan.

Conclusion and implications: These results demonstrate that liquiritigenin exerts anti‐inflammatory effects, which results from the inhibition of NF‐κB activation in macrophages, thereby decreasing production of iNOS and proinflammatory cytokines. Our findings showing inhibition by liquiritigenin of paw oedema as well as inflammatory gene induction will help to understand the pharmacology and mode of action of liquiritigenin, and of the anti‐inflammatory use of Glycyrrhizae radix.