bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface plasmon resonance study on binding interactions of multivalent cyclophane hosts with immobilized guests
Authors: Hayashida Osamu , Sato Daisuke
Published: December 2009

Guest‐binding affinities of water‐soluble cyclophane heptadecamer (1) and pentamer (2) with immobilized guests such as 1‐pyrenylmethylamine (PMA) and 2‐(1‐ naphthyl)ethylamine (NEA) were investigated by surface plasmon resonance (SPR) measurements. As a typical example, the binding constants (K) for 1 and 2 with the immobilized PMA as a guest were evaluated to be 2.5 × 107 and 2.7 × 106 M−1, respectively, and were much larger than that of a monocyclic reference cyclophane (K, 2.5 × 104 M−1). Interestingly, in the complexation of 1 and 2 with the immobilized guests, more favorable association and dissociation rate constant values (ka and kd, respectively) were observed in comparison with those for the monocyclic cyclophane, reflecting multivalent effects in macrocycles. The multivalent effects in macrocycles as well as molecular recognition abilities of the cyclophane oligomers were confirmed even when the guest molecules were immobilized on SPR sensor chip surfaces. Copyright © 2009 John Wiley & Sons, Ltd.
A constitutive model for the nonlinear viscoplastic behavior of thermoplastic olefin
Authors: Ma Qiu , Su Xuming , Lin Zhongqin , Lasecki John , Lai Xinmin
Published: December 2009

A tangent constitutive model was developed in this article to address the nonlinear viscoplastic behavior of compound grade thermoplastic olefin (TPO). The TPO was commonly blends of polypropylene matrix, rubber, and inorganic filler. The constitutive model for TPO was obtained from the combination of the mechanical behavior of the matrix and fillers. In a multiphase material, the rate‐dependent behavior of polypropylene matrix was presented by a physically based constitutive model for large strain deformation, while the deformation behavior of rubber and talc were captured by Hooke's law. The average strain of each phase, as well as the strain of the voids caused by cavitation of rubber and debonding of talc, was determined by the Mori‐Tanaka method, in conjunction with a tangent modulus approach. To test the applicability of the developed model, it was applied to calculate the rate dependent stress‐strain relations of TPO. The model was predictive of the initial rate‐dependent stiffness, yield, and strain hardening response in large strain deformation. The constitutive model was incorporated into a finite element code to predict the large strain deformation behavior of TPO. The initiation of necking and neck propagation were obtained and confirmed by experimental observation. POLYM COMPOS., 2010. © 2009 Society of Plastics Engineers
Study on mechanical and flow properties of acrylonitrile‐butadiene‐styrene/poly(methyl methacrylate)/nano‐calcium carbonate composites
Authors: Zhang Aimin , Zhao Guoqun , Guan Yanjin , Chen Guowen
Published: December 2009

Acrylonitrile‐butadiene‐styrene (ABS)/poly(methyl meth‐acrylate) (PMMA)/nano‐calcium carbonate (nano‐CaCO3) composites were prepared in a corotating twin screw extruder. Four kinds of nano‐CaCO3 particles with different diameters and surface treatment were used in this study. The properties of the composites were analyzed by tensile tests, Izod impact tests, melt flow index (MFI) tests, and field emission scanning electron microscopy (FESEM). This article is focused on the effect of nano‐CaCO3 particles' size and surface treatment on various properties of ABS/PMMA/nano‐CaCO3 composites. The results show that the MFI of all the composites reaches a maximum value when the content of nano‐CaCO3 is 4 wt%. In comparison with untreated nano‐CaCO3 composites, the MFI of stearic acid treated nano‐CaCO3 composites is higher and more sensitive to temperature. The tensile yield strength decreases slightly with the increase of nano‐CaCO3 content. However, the size and surface treatment of nano‐CaCO3 particles have little influence on the tensile yield strength of composites. In contrast, all of nano‐CaCO3 particles decrease Izod impact strength significantly. Stearic acid treated nano‐CaCO3 composites have superior Izod impact strength to untreated nano‐CaCO3 composites with the same nano‐CaCO3 content. Furthermore, the Izod impact strength of 100 nm nano‐CaCO3 composites is higher than that of 25 nm nano‐CaCO3 composites. POLYM. COMPOS., 31:1593–1602, 2010. © 2009 Society of Plastics Engineers
PAPP‐A and free ß‐hCG stability in first trimester serum using PerkinElmer AutoDELFIA® and DELFIA® Xpress systems
Authors: Cowans Nicholas J. , Stamatopoulou Anastasia , Hellström Johanna , Mäkelä Minna‐Maarit , Spencer Kevin
Published: December 2009

Background

In this study we aim to investigate the stability of free‐β‐hCG and PAPP‐A over time in serum and whole blood in typical routine temperatures.

Methods

Serum pools were stored under the following temperatures: 30°C, room temperature, refrigerator temperature and −20°C, for up to 240 days. Stability of the markers in whole blood was examined in a shorter study and compared to serum. Samples were analysed using the AutoDELFIA® and DELFIA® Xpress analysers.

Results

On the AutoDELFIA®, considering a 10% change acceptable, PAPP‐A levels are stable in serum for 142 days at refrigerator temperature, 37 days at room temperature and 20 days at 30°C. Free‐β hCG is stable in serum for 94 days at refrigerator temperature, 3 days at room temperature and 12 h at 30°C. There was no significant change with either analyte after −20°C storage for up to 240 days or after six repeated freeze–thaw cycles. In whole blood, free‐β hCG levels increased more rapidly compared to serum, especially at 30°C.

Conclusion

Normal handling of samples is only likely to minimally effect the risk assessment of chromosomal anomalies. However, careful attention should be paid to minimise the increase of free‐β hCG levels in samples shipped as whole blood. Copyright © 2009 John Wiley & Sons, Ltd.
Signal detection for vaccine side effects that have not been specified in advance
Authors: Walker Alexander M.
Published: December 2009

An information‐theoretic definition of similarity proposed by Dekang Lin in 1998 appears to have attractive properties for identifying medically similar cases in a large database. Examination of similar cases that appear following vaccination may provide a way of detecting previously unexpected associations. A key element here is the inclusion of shared time‐since‐vaccination as a dimension of similarity while considering concordance on many other features. The system is potentially much more sensitive to patterns with multiple features than are very large, high‐dimension contingency tables. Copyright © 2009 John Wiley & Sons, Ltd.
Measuring exacerbations in obstructive lung disease
Authors: Velthove Karin J. , Souverein Patrick C. , van Solinge Wouter W. , Leufkens Hubert G. M. , Lammers Jan‐Willem J.
Published: December 2009

Purpose

Using hospitalization always has been seen as a solid measurement for exacerbation in pharmacoepidemiology, but might lead to an underestimation of disease exacerbation because of a trend towards outpatient care. The aim of this study was to quantify the incidence of different exacerbation markers in obstructive lung disease and to identify predictors for these exacerbation markers.

Methods

We conducted a cohort study using the PHARMO record linkage system, including demographic details and complete medication histories of more than two million community‐dwelling residents in the Netherlands from 1985 onwards. Eligible patients were adult users of inhaled corticosteroids (ICS). Outcome parameters were hospitalization and short courses of systemic corticosteroids. Patients were allowed to have multiple exacerbations during follow‐up.

Results

We identified 5327 patients. During follow‐up, 8635 exacerbations occurred in 2332 patients with a trend in time towards treating exacerbations out of the hospital (p‐value 0.003). Of all patients with exacerbations, 73% was not hospitalized during follow‐up. Exacerbations were associated with high‐dose ICS use (adjusted RR 1.4; 95% CI 1.2–1.7) and chronic systemic corticosteroid use (adjusted RR 1.9; 95%CI 1.6–2.2).

Conclusions

Using hospitalization only as exacerbation marker leads to underestimating the exacerbation rate, because of exacerbation treatment out of the hospital. Patients with obstructive lung disease using chronic systemic corticosteroids or high‐dose ICS use are more prone to exacerbations. This implies that these patients should be monitored carefully to prevent recurrent exacerbations which are detrimental for their prognosis and quality of life. Copyright © 2009 John Wiley & Sons, Ltd.
Trends in the non‐steroidal anti‐inflammatory drug market in six Central–Eastern European countries based on retail information
Authors: Inotai András , Hankó Balázs , Mészáros Ágnes
Published: December 2009

Purpose

The objective of this study was to evaluate the non‐steroidal anti‐inflammatory drug market of six Central and Eastern European countries. Trends and similarities were compared across the examined countries.

Methods

The Intercontinental Marketing Service Health database was used to determine consumption data between the years 2000 and 2007. We applied the anatomical therapeutical chemical‐defined daily dose method, focussing on three major non‐steroidal anti‐inflammatory drug groups: conventional non‐steroidal anti‐inflammatory drugs, ‘stronger cyclooxygenase 2 inhibitors’ (all together as: non‐cyclooxygenase 2 selective non‐steroidal anti‐inflammatory drugs) and selective cyclooxygenase 2 inhibitors. The main outcome measure was defined daily dose/1000 inhabitants/day. Different active agents have been distinguished between the three major groups.

Results

In total the non‐steroidal anti‐inflammatory drug group reached a 42.82–74.17 defined daily dose/1000 inhabitants/day volume in 2007, with an average total increase of 25.1% between 2002 and 2007. In the conventional non‐steroidal anti‐inflammatory drug group, diclofenac and ibuprofen have attained the highest consumption. Our results show a notable increase (325%, 2002–2007) of the ‘stronger cyclooxygenase 2 inhibitor group’ (nimesulide and meloxicam). Trends of selective cyclooxygenase 2 inhibitor volumes differ within the observed countries.

Conclusion

Differences in the six countries concerning their NSAID consumption and market trends could not be explained with the inequalities in patient characteristics. The conventional NSAID retail gave the majority of the total NSAID market. The consumption of selective COX2 inhibitors in all of the six countries were much lower than in the US or Australia. The NSAID risk profile in the region is comparable to previous studies in other countries. Copyright © 2009 John Wiley & Sons, Ltd.
Chiral copolymers of (R)‐N‐(1‐phenylethyl) methacrylamide and 2‐hydroxyethyl methacrylate: copolymerization characteristics and chiroptical properties
Authors: Bag Dibyendu S , Rao KU Bhasker
Published: December 2009

The aim of this investigation was the copolymerization of a chiral monomer, (R)‐N‐(1‐phenylethyl) methacrylamide, with an achiral monomer, 2‐hydroxyethyl methacrylate (HEMA). The copolymerization characteristics as well as the chiroptical properties (optical rotation and circular dichroism) and their variation with copolymer composition and temperature are discussed. The copolymers are statistical and enriched in HEMA. The monomer reactivity ratio of the chiral monomer (r1) is 0.133 whereas that of HEMA (r2) is 1.042 based on the Kelen–Tudos method. The sequence of consecutive chiral monomer units predominates for a feed composition between 0.5 and 0.9 (mole fraction). On the other hand, the sequence of HEMA is uniform and it predominates for a feed composition of around 0.5 (mole fraction). The chiroptical properties of the copolymers do not vary linearly with the content of chiral units in the copolymers. The optical rotation and circular dichroism attain optimum values above 30–40 mol% of chiral monomer units in the copolymers. However, the circular dichroism of the copolymers varies linearly with the temperature. The chiral monomer being a more bulky structure is less reactive than HEMA. The nonlinear variation of chiroptical properties of the copolymers with the content of chiral units may be due to the secondary interaction in the copolymers associated with the hydrogen bonding involving the amide linkage (CONH) present in the pendant chromophore of the chiral monomer as well as the hydroxyl pendant group of HEMA and also the aromatic π–π interaction. Copyright © 2009 Society of Chemical Industry
Dispersity in polymer science (IUPAC Recommendation 2009)
Authors: Stepto R. F. T.
Published: December 2009

This recommendation defines just three terms, viz., 1. molar‐mass dispersity, relative‐molecular‐mass dispersity, or molecular‐weight dispersity, 2. degree‐of‐polymerization dispersity, and 3. dispersity. “Dispersity” is a new word, coined to replace the misleading, but widely used term “polydispersity index” for M̄w/M̄n and X̄w/X̄n. The document, although brief, also has a broader significance in that it seeks to put the terminology describing dispersions of distributions of properties of polymeric (and non‐polymeric) materials on an unambiguous and justifiable footing. Copyright © 2009 Society of Chemical Industry
Cancer‐related concerns of spouses of women with breast cancer
Authors: Fletcher Kristin A. , Lewis Frances Marcus , Haberman Mel R.
Published: December 2009

Objective: To describe spouses' reported cancer‐related demands attributed to their wife's breast cancer, and to test the construct and predictive validity of a brief standardized measure of these demands.

Methods: Cross‐sectional and longitudinal data were obtained from 151 spouses of women newly diagnosed with non‐metastatic breast cancer. Descriptive statistics were computed to describe spouses' dominant cancer‐related demands, and multivariate regression analyses tested the construct and predictive validity of the standardized measure.

Results: Five categories of spouses' cancer‐related demands were identified, such as concerns about spouses' own functioning, wife's well‐being and response to treatment, couples' sexual activities, the family's and children's well‐being, and the spouses' role in supporting their wives. A 33‐item short version of the standardized measure of cancer demands demonstrated construct and predictive validity that was comparable to a 123‐item version of the same questionnaire. Greater numbers of illness demands occurred when spouses were more depressed and had less confidence in their ability to manage the impact of the cancer (F=18.08 (3,103), p<0.001). Predictive validity was established by the short form's ability to significantly predict the quality of marital communication and spouses' self‐efficacy at a 2‐month interval.

Conclusion: The short version of the standardized measure of cancer‐related demands shows promise for future application in clinic settings. Additional testing of the questionnaire is warranted. Spouses' breast cancer‐related demands deserve attention by providers. In the absence of assisting them, spouses' illness pressures have deleterious consequences for the quality of marital communication and spouses' self‐confidence. Copyright © 2009 John Wiley & Sons, Ltd.
Flow Dynamic Characterization of Cylindrical Particles
Authors: Asif Mohammad
Published: December 2009

A detailed experimental characterization of the flow dynamics of a closely sized sample of cylindrical particles is reported here. Issues relevant to the design of reacting and nonreacting fluid‐solid contacting devices, e.g., pressure drop behavior, fluidization behavior and settling behavior, both in Stokes law as well as the intermediate region, were investigated. The common approach of extending correlations meant for predicting the fluid dynamic parameters of spherical particles to nonspherical particles, with the help of the sphericity shape factor, such that particle diameter is the product of the equivalent volume diameter and the sphericity of the nonspherical particle, was examined here. Notwithstanding the simplicity of this approach, caution must be exercised as far as fluid dynamic parameters thus obtained are concerned. Significant error was observed here in all cases. However, improved predictions were obtained using available correlations whose parameters were optimized using a database of nonspherical particles.
The High‐Pressure Characterization of Energetic Materials: Diaminotetrazolium Nitrate (HDAT‐NO3)
Authors: Ciezak Jennifer A.
Published: December 2009

In‐situ high‐pressure room temperature synchrotron X‐ray diffraction and optical Raman and infrared spectroscopy were used to examine the structural properties, equation of state, and vibrational dynamics of diaminotetrazolium nitrate (HDAT‐NO3). The X‐ray measurements show that the pressure–volume relations remain smooth to 12 GPa. X‐ray diffraction measurements at pressures above 12 GPa were not possible in this study because of sample decomposition resulting from several factors. X‐ray diffraction reveals no indication of a phase transition to at least 12 GPa, but slight variations in the c/b unit cell ratio suggests modifications within the hydrogen bonding sub‐lattice. Vibrational measurements show the ambient phase of HDAT‐NO3 to remain the dominant phase to 33 GPa.
Efficacy of vaporised ethyl formate/carbon dioxide formulation against stored‐grain insects: effect of fumigant concentration, exposure time and two grain temperatures
Authors: Damcevski Katherine A , Dojchinov Greg , Woodman James D , Haritos Victoria S
Published: December 2009

BACKGROUND: The ethyl formate/carbon dioxide (CO2) formulation Vapormate™ is a rapid‐acting fumigant being developed for the control of stored‐grain insects. The effects have been investigated of concentration, exposure times of 1, 3, 24 and 72 h and two grain temperatures, 15 and 25 °C, on its efficacy against mixed‐stage cultures of Sitophilus oryzae (L.) Tribolium castaneum (Herbst) and strongly phosphine‐resistant Rhyzopertha dominica (F.) strain QRD569.

RESULTS: High mortalities (≥92%) of mixed‐stage cultures of all three species were obtained when grain was fumigated with the formulation (193 g m−3 ethyl formate) for 1 h. Complete control of R. dominica QRD569 and T. castaneum was achieved with 63 and 76 g m−3 ethyl formate respectively, with exposure for 24 h, whereas mean mortality of S. oryzae was 86% under the same conditions. Mortalities of S. oryzae juvenile stages were significantly lower than adults under the conditions tested, which was due to pronounced tolerance of mid‐stage pupae to the fumigant. Reducing grain temperature from 25 to 15 °C had no effect on insect mortality.

CONCLUSION: Ethyl formate/CO2 formulation is highly effective against stored‐grain insects over a range of concentrations and exposure times. Efficacious fumigations were conducted in as little as 1 h, and a strongly phosphine‐resistant R. dominica strain was readily controlled with the fumigant. Copyright © 2009 CSIRO, Australia. Published by John Wiley & Sons, Ltd
More than methods: learning from research with children seeking asylum in Ireland
Authors: White Allen , Bushin Naomi
Published: December 2009

In this paper we explore the ways in which the methodological and analytical complexities that are encountered when researching with children have stimulated particular approaches that are useful to consider in the context of research with both adults and children who are refugees or seeking asylum. We draw upon ideas related to performativity to argue that the methods and activities we employ in research encounters ‘in‐the‐field’ play a key role in facilitating research participants' efforts to express their subjectivities and identities. Drawing on fieldwork with children in an accommodation centre for asylum‐seeking families in Ireland, we argue that using child‐centred research methods can be understood as specific moments within which materials become available for research participants (children) to develop and enhance their social and cultural identities in many different ways. The use of multiple and participatory methods that children engaged with, adapted or ignored (as they chose), enabled and resulted in children representing themselves as individuals in families seeking asylum, rather than as ‘asylum‐seeker children’. This paper supports work that suggests that ways of approaching participatory research with children may be useful when researching other populations, but it goes beyond this point to assert that research encounters may provide participants with exceptional resources for explaining their lives. Copyright © 2009 John Wiley & Sons, Ltd.
Graphene growth by molecular beam epitaxy using a solid carbon source
Authors: Moreau E. , Ferrer F. J. , Vignaud D. , Godey S. , Wallart X.
Published: December 2009

The direct elaboration of graphene by molecular beam epitaxy (MBE) has been studied, using a solid carbon source. Successful growth has been achieved on both the carbon and silicon terminated faces of silicon carbide substrates in the temperature range 1000–1100 °C, as confirmed by low energy electron diffraction (LEED) and X‐ray photoemission spectroscopy (XPS) analysis. Atomic force microscopy (AFM) observations show that the initial substrate structure, i.e. flat atomic terraces and half‐period high steps, remains almost unaffected during the growth, contrary to what is observed following the graphitization process.
Top‐ and side‐gated epitaxial graphene field effect transistors
Authors: Li Xuebin , Wu Xiaosong , Sprinkle Mike , Ming Fan , Ruan Ming , Hu Yike , Berger Claire , de Heer Walt A.
Published: December 2009

Three types of first generation epitaxial graphene (EG) field effect transistors (FET) are presented and their relative merits are discussed. Graphene is epitaxially grown on both the carbon and silicon faces of hexagonal silicon carbide and patterned with electron beam lithography. The channels have a Hall bar geometry to facilitate magnetoresistance measurements. FETs patterned on the Si‐face exhibit off‐to‐on channel resistance ratios that exceed 30. C‐face FETs have lower off‐to‐on resistance ratios, but their mobilities (up to 5000 cm2/Vs) are much larger than that for Si‐face transistors. Initial investigations into all‐graphene side‐gate FET structures are promising. Conductivity (left panel) and transport resistances ρxx and ρxy of a top gate graphene Hall bar on SiC Si‐face, showing a sign reversal of the hall coefficient at the resistance peak.

magnified image
In vitro cytotoxic, antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu
Authors: Bradacs Gesine , Maes Louis , Heilmann Jörg
Published: December 2009

Sixty‐three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth. significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq. displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam. I as well as the stems of Macropiper latifolium (L.f.) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity. Copyright © 2009 John Wiley & Sons, Ltd.
Prediction of Ion Drift Times for a Proteome‐Wide Peptide Set Using Partial Least Squares Regression, Least‐Squares Support Vector Machine and Gaussian Process
Authors: Liu Xiuhong , Liang Jun , Fan Jicai , Shang Zhicai
Published: December 2009

Quantitative structure‐property relationships (QSPRs) have been developed to predict the ion mobility spectrometry (IMS) drift time tD for a set of 1481 peptides generated by protease digestion of the Drosophila melanogaster proteome using information directly derived from molecular structures. The relationship between peptide structure and the drift time tD was constructed by using partial least squares regression (PLS), least‐squares support vector machine (LSSVM) and Gaussian process (GP) coupled with genetic algorithm‐variable selection. Among these models, the linear PLS was incapable of capturing all dependences in this peptide system; nonlinear LSSVM and GP methods presented a good statistical performance on reproducing peptide mobility behavior. Moreover, since GP was able to handling both linear and nonlinear‐hybrid relationship, it gave a stronger fitting ability and a better predictive power than the LSSVM. Systematic analysis of the GP model showed that diversified properties contribute remarkable effect to the relationship between the drift time and the peptide structure. Particularly, the structural topological information and charge distribution contribute significantly to the drift time of peptides.
Molecular Modeling and Receptor‐Dependent (RD) 3D‐QSAR Approach to a Set of Antituberculosis Derivatives
Authors: Pasqualoto Kerly Fernanda Mesquita , Ferreira Márcia Miguel Castro
Published: December 2009

In this study, receptor‐dependent (RD) 3D‐QSAR models were built for a set of thirty‐seven isoniazid derivatives bound to the enoyl‐acp reductase from M. tuberculosis, called InhA (PDB entry code 1zid). Ligand‐receptor (L‐R) molecular dynamics (MD) simulations [500 000 steps; the step size was 0.001 ps (1 fs)] were carried out at 310 K (biological assay temperature). The hypothesized active conformations resulting from a previously reported receptor‐independent (IR) 4D‐QSAR analysis were used as the molecular geometries of each ligand in this structure‐based L‐R binding research. The dependent variable is the reported MIC values against M. tuberculosis var. bovis. The independent variables (descriptors) are energy terms of a modified first‐generation AMBER force field combined with a hydration shell aqueous solvation model. Genetic function approximation (GFA) formalism and partial least squares (PLS) regression were employed as the fitting functions to develop 3D‐QSAR models. The bound ligand solvation energy, the sum of electrostatic and hydrogen bonding energies of the unbound ligand, the bending energy of the unbound ligand, the electrostatic intermolecular L‐R energy, and the change in hydrogen bonding energy upon binding were found as important energy contributions to the binding process. The 3D‐QSAR model at 310 K has good internal and external predictability and may be regarded as representative of the binding process of ligands to InhA.
Selection of Appropriate Training Set of Chemicals for Modeling Dermal Permeability Using Uniform Coverage Design
Authors: Vijay Vikrant , Baynes Ronald E. , Young S. Stanley , Riviere Jim E.
Published: December 2009

In silico approaches to model dermal permeability require a training set of chemicals. Selection of an appropriate set of chemicals is the key factor in the precision of a model. The objective is to develop a training set of chemicals representing a wider chemical space relevant to biological activity such as dermal permeability and compare it with the currently used training set of chemicals by our laboratory, which was based on a subjective selection process. Wider chemical space refers to structurally diverse chemicals with a wide range of all the descriptor values. A parent dataset of 4098 chemicals with 5 solvatochromic descriptors obtained from ADME boxes database was used for this study. The approach for diverse chemical selection was performed using ‘uniform coverage design’ (UCD) run by SpaceFill program and compared with a cluster analysis using SAS. Five sets of 25 chemicals were obtained from the design and evaluated based on gas chromatographic assay amenability and representation of structurally diverse group. A final set of 25 chemicals to be used for modeling dermal permeability was selected, based on aforementioned criteria. Graphical plot of the principal components demonstrated that currently used training set of chemicals have narrow representation of parent dataset whereas the selected training set have appropriate representation in terms of chemical space. QSAR models were built from both training set of chemicals. The model based on the 25 selected chemicals (R2=0.83) performed equally if not slightly better then the model based on currently used training set of 32 chemicals (R2=0.82).
Nonlinear optical properties of the M @ C60 endohedrals (M = Cs, Li, and Na)
Authors: Yaghobi M. , Koohi A.
Published: December 2009

The Hartree–Fock (HF) approximation and the Single‐excitation configuration interaction (single‐CI) method are used, with sum‐over‐state (SOS) approach, in order to determine the static (ω = 0) and frequency dependent linear and non linear optical (NLO) properties of the M @ C60 endohedrals (M = Cs, Li, and Na). We discuss the effects of displacement, movement direction, and type of atom on the (hyper) polarizability of the M at C60 endohedrals. A HF‐single‐CI model yields the (hyper) polarizability magnitudes and spectra, which are in agreement with experiment. Our results indicate that the movement of the atom (M) effect on the NLO spectra of M @ C60 endohedrals is dramatic. These results may provide new means to design some new types of NLO materials. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
DFT performance for the hole transfer parameters in DNA π stacks
Authors: Félix Martín , Voityuk Alexander A.
Published: December 2009

Recently, we showed that unoccupied Kohn‐Sham (KS) orbitals stemming from DFT calculations of a neutral system can be used to derive accurate estimates of the free energy and electronic couplings for excess electron transfer in DNA (Félix and Voityuk, J Phys Chem A 2008, 112, 9043). In this article, we consider the propagation of radical cation states (hole transfer) through DNA π‐stacks and compare the performance of different exchange‐correlation functionals to estimate the hole transfer (HT) parameters. Two different approaches are used: (1) calculations that use occupied KS orbitals of neutral π stacks of nucleobases, and (2) the time‐dependent DFT method which is applied to the radical cation states of these stacks. Comparison of the calculated parameters with the reference data suggests that the best results are provided by the KS scheme with hybrid functionals (B3LYP, PBE0, and BH&HLYP). The TD DFT approach gives significantly less accurate values of the HT parameters. In agreement with high‐level ab initio results, the KS scheme predicts that the hole in π stacks is confined to a single nucleobase; in contrast, the spin‐unrestricted DFT method considerably overestimates the hole delocalization in the radical cations. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Many‐body effects on structures of small Ca2+Arn clusters
Authors: Gaied W. , Ben El Hadj Rhouma M.
Published: December 2009

The structure and stabilities of Ca2+Arn (n = 1–24) clusters are investigated using analytical potential functions. The energy of the systems, in its ground state, is described using additive potentials with V(Ca2+‐Ar) and V(Ar‐Ar) representing the pair potential interactions, and many‐body effects are described using the interaction between dipoles induced by the calcium ion. To find the geometry of the lowest energy isomers of Ca2+Arn clusters, we use the so‐called basin‐hopping method of Wales et al. We show that in the equilibrium structures of Ca2+Arn clusters, the Ca2+ cation is always solvated by argon clusters. For n = 2, we have found a strong competition between the symmetric linear shape (D∞) and the bent isomer (C2v). The relative importance of the three‐body interactions due to the presence of the induced dipoles on the Ar atoms can be inferred from the magnitude of the known Ar2 interaction, and lead to a more stabilized linear structure. The global minimum of Ca2+Ar3 is planar (D3h), but a second three‐dimensional isomer with a pyramidal C3v symmetry exists. The absolute minimum of Ca2+Ar4 is a regular tetrahedron, and that of Ca2+Ar6, is a regular octahedron. The particularly stable sizes with respect to their immediate neighbors were studied by calculating the second energy difference between size n and its immediate neighbors. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Ab initio study of the potential energy surface and product branching ratios for the reaction of O(1D) with CH3CH2Br
Authors: Tian Zhimei , Song Chongfu , Li Quanxin
Published: December 2009

The potential energy surface of O(1D) + CH3CH2Br reaction has been studied using QCISD(T)/6‐311++G(d,p)//MP2/6‐311G(d,p) method. The calculations reveal an insertion‐elimination reaction mechanism of the title reaction. The insertion process has two possibilities: one is the O(1D) inserting into CBr bond of CH3CH2Br producing one energy‐rich intermediate CH3CH2OBr and another is the O(1D) inserting into one of the CH bonds of CH3CH2Br producing two energy‐rich intermediates, IM1 and IM2. The three intermediates subsequently decompose to various products. The calculations of the branching ratios of various products formed though the three intermediates have been carried out using RRKM theory at the collision energies of 0, 5, 10, 15, 20, 25, and 30 kcal/mol. CH3CH2O + Br are the main decomposition products of CH3CH2OBr. CH3COH + HBr and CH2CHOH + HBr are the main decomposition products for IM1; CH2CHOH + HBr are the main decomposition products for IM2. As IM1 is more stable and more likely to form than CH3CH2OBr and IM2, CH3COH + HBr and CH2CHOH + HBr are probably the main products of the O(1D) + CH3CH2Br reaction. Our computational results can give insight into reaction mechanism and provide probable explanations for future experiments. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
A biplanar robot navigation system for the distal locking of intramedullary nails
Authors: Lei Hu , Sheng Luan , Manyi Wang , Junqiang Wang , Wenyong Liu
Published: December 2009

Background

Distal locking is the key procedure of the intramedullary nailing operation. It is difficult to precisely locate the locking path, and intraoperative radiation exposure is also a serious problem. The advantages and disadvantages of different approaches applied in this operation are summarized.

Method

A biplanar robot navigation system for the distal locking of intramedullary nails is presented. The novel mechanical structure and the surgical process are introduced. Then the positioning accuracy of the robot is experimented and validated.

Results

The positioning precision of the biplanar robot is tested, and the average error is 0.24 mm. The tibia sawbone is used for distal locking to test the accuracy of the robot navigation system. The maximal deviation between the drilling centre and the nail hole centre is 0.44 mm.

Conclusion

The biplanar robot has the advantages of high positioning accuracy, operational stability and safety. It can be used not only for the distal locking of intramedullary nails but also for other orthopaedic surgeries that demand precise positioning. Copyright © 2009 John Wiley & Sons, Ltd.
Three‐dimensional A‐mode ultrasound calibration and registration for robotic orthopaedic knee surgery
Authors: Mozes Alon , Chang Ta‐Cheng , Arata Louis , Zhao Weizhao
Published: December 2009

Background

Registration is a key step for computer‐navigated robot‐assisted surgery. Registration links the live patient anatomical location to the prescanned CT or MRI images, so that predesigned procedures can be performed accurately. Fiducial markers or mechanical probes are usually used to identify anatomical features or collect data points for registration. This conventional invasive approach is common; however, using ultrasound probes may provide a non‐invasive alternative.

Methods

This report presents investigations of selecting an A‐mode ultrasound transducer, calibrating it, analysing the ultrasound signal and using it to register phantom‐sawbones of tibia and femur as well as cadaveric specimens. To ensure accurate registration, the A‐mode ultrasound probe is calibrated by a designed calibration system. Detailed mathematical derivation and procedures for the calibration are provided in the Appendix. The calibration and registration experiments were performed in conjunction with MAKO Surgical Corporation's Tactile Guidance System™ (TGS™) at their headquarters and at the South Florida Spine Clinic for cadaveric experiments.

Results

Calibration results show that an A‐mode ultrasound probe can reach the same accuracy level as a mechanical probe. By using the A‐mode ultrasound probe, averaged root mean square errors (RMSE) are <0.5 mm for calibration, <1.0 mm for phantom‐sawbones and <2.0 mm for cadaveric specimens.

Conclusion

The registration results from phantom and cadaveric experiments are suitable for clinical applications. A‐mode ultrasound registration is a viable option for registration of the bones in orthopaedic knee surgery but with reduced incision size. Copyright © 2009 John Wiley & Sons, Ltd.
Differentiated security in wireless mesh networks
Authors: Gamer Thomas , Völker Lars , Zitterbart Martina
Published: December 2009

The upcoming IEEE 802.11s standard enables easy establishment and maintenance of wireless mesh networks in residential and enterprise scenarios. They, however, need special attention with respect to security. Due to multi‐hop communication and routing on layer 2 in mesh networks, attacks on the routing, selective forwarding, and eavesdropping on confidential data become relatively easy. To avoid such attacks, we introducedifferentiated securitywhich is based on protection levels associated with nodes in the network. Participation in the MAC layer routing is facilitated according to the respective protection level of a node. Using additional cryptographic protection our approach can also avoid unintentional disclosure of confidential data. Copyright © 2009 John Wiley & Sons, Ltd.
Performance of Al alloys following excimer LSM—anodising approaches
Authors: Viejo F. , Aburas Z. , Coy A. E. , Garcia‐Garcia F. J. , Liu Z. , Skeldon P. , Thompson G. E.
Published: December 2009

The potential application of laser surface melting (LSM) as a pre‐treatment prior to conventional anodising in sulfuric acid electrolyte has been evaluated. For this purpose, AA2050‐T8 (AlCuLi) and AA2024‐T351 (AlCuMg) aerospace alloys were compared. For LSM, a KrF excimer laser (248 nm) was used, with variation of the number of pulses received per unit area. After LSM, the specimens were anodised at a constant voltage of 12 V in 0.46 M H2SO4 for different times from 4 to 20 min, followed by sealing in boiling water for 30 min. Material characterisation, in terms of surface morphology, microstructural and laser‐induced phase transformations, was performed using scanning and transmission electron microscopies (TEMs). The corrosion behaviour was evaluated using the ASTM G34‐01 EXCO test at 25 °C for 6 h. The results showed that excimer LSM, used as a pre‐treatment prior to anodising, greatly improved the anodising performance, through the dissolution of intermetallic phases in the near‐surface alloy. Further, different exfoliation susceptibility was observed by comparing both alloys, being strongly dependent on the presence and distribution of the main constituent phases, e.g. T1 (Al2CuLi) and S (Al2CuMg) phases, for AA2050‐T8 and AA2024‐T351, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
Estimation of the effect size in meta‐analysis with few studies
Authors: Longford Nicholas T.
Published: December 2009

Meta‐analysis is often conducted with only a small number of studies. Adjustments of the (restricted) maximum likelihood estimator of the effect size are derived and their gains in efficiency are explored. The proposed estimators are applied to three sets of studies. Copyright © 2009 John Wiley & Sons, Ltd.
An introduction to the contemporary update
Authors: Dunkle John H.
Published: December 2009

While the higher education landscape has changed significantly over the past two decades, the AISP model remains a very useful framework for student affairs professionals at all levels.
The AISP model: Assessment‐Intervention of Student Problems
Authors: Delworth Ursula
Published: December 2009

The Assessment‐Intervention of Student Problems model provides a comprehensive process for understanding and helping students who are either having problems themselves or are causing problems for others on campus.
A senior student affairs officer's perspective on the AISP model
Authors: Sandeen Arthur
Published: December 2009

The AISP model is particularly appealing to senior student affairs officers because it is not complicated and it emphasizes assessment and a coordinated team approach for making sound decisions about students of concern.
The AISP model on increasingly diverse campuses
Authors: Shang Paul , Barkis Marita
Published: December 2009

How can cultural awareness assist campus intervention teams to promote a campus of care? This chapter describes the implications of the AISP model and campus intervention teams in the context of greater campus diversity.
Effect of age‐dependent exposure to lead on hepatotoxicity and nephrotoxicity in male rats
Authors: Berrahal Alya Annabi , Lasram Montassar , El Elj Naziha , Kerkeni Abdelhamid , Gharbi Najoua , El‐Fazâa Saloua
Published: December 2009

Lead is known to induce a broad range of physiological, biochemical, and behavioral dysfunctions in laboratory animals and humans. This includes age‐specific variations in absorption, retention, and tissue distribution of lead. This study was carried out to investigate the effects of chronic exposure to lead (50 mg/L) on liver and kidneys of two different age groups of male rats treated with lead from delivery until puberty period (40 days) and postpuberty period (65 days). For this purpose, the concentrations of thiobarbituric acid reactive substance (TBARS), total thiol groups (SH), and superoxide dismutase (SOD) activity were measured in the liver and kidney of rats. Renal function was analyzed by determining creatinine, acid uric, and urea. Plasma activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and albumin were determined spectrophotometrically to evaluate hepatic function. These markers of damage were determined to assess the level of toxicity in these animals. Our results clearly show that the administration of lead produces oxidative damage in liver and kidney, as strongly suggested by the significant increase in TBARS, decrease in total SH, and the alteration of SOD activity. In young lead‐exposed animals, lead‐induced perturbations on the synthetic function of the liver and the kidney were more pronounced. However, nephropathy is evident for adult lead‐exposed animals. It is concluded that lead induces severe hepatic and renal toxicity, which depends on the age of the animals and the target organ. © 2009 Wiley Periodicals, Inc. Environ Toxicol 26: 68–78, 2011.
A study of the subchronic effects of arsenic exposure on the liver tissues ofLabeo rohitausing Fourier transform infrared technique
Authors: Palaniappan PL.R M. , Vijayasundaram V. , Prabu S. Milton
Published: December 2009

In this work, an attempt has been made to study the subchronic effects of arsenic exposure on the biochemical composition; mainly proteins of the liver tissues ofLabeo rohitafingerlings by using Fourier transform infrared (FT‐IR) spectroscopic technique. The study was carried out using a Perkin Elmer‐Spectrum Rx1 spectrometer. Because of arsenic exposure, significant reductions in the intensity as well as area of amide bands have been observed in the liver tissues. The decreased intensity of the amide bands could be interpreted as the result of alteration of the protein synthesis due to the high affinity of metal compounds towards different amino acid residues of proteins. Further,meso‐2, 3‐dimercaptosuccinic acid (DMSA) treatment shows the recovery of the protein content in the liver tissues. To confirm that the changes observed are only due to the bio‐accumulation of arsenic, the concentration of arsenic in the liver tissues ofLabeo rohitawas determined by using Inductively Coupled Plasma‐Optical Emission Spectrometry (ICP‐OES). It is observed that the arsenic level in the control tissues is found to be below detectable limit, whereas the arsenic exposed liver shows an accumulation of 66.68 ± 0.43 μg/g and DMSA treatment reduces the arsenic content to 17.96 ± 0.19 μg/g. In conclusion, this study gives clear evidence that the use of FT‐IR spectroscopy is a powerful approach to achieve more insight into the protein alterations caused by arsenic. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Three‐dimensional multiplanar ultrasound is a valuable tool in the study of the fetal profile in the second trimester of pregnancy
Authors: De Jong‐Pleij E. A. P. , Ribbert L. S. M. , Tromp E. , Bilardo C. M.
Published: December 2009

Objectives

To evaluate the additional value of three‐dimensional (3D) multiplanar ultrasound in the examination of the fetal profile.

Methods

Two 3D volumes of the fetal head were obtained from 84 fetuses at 22 to 29 weeks' gestation. The volumes were taken starting at the midsagittal plane with the fetus facing the transducer. The success rate and acquisition time to obtain each volume and display the exact midsagittal plane by 3D multiplanar ultrasound were analyzed. The correction angles from the original two‐dimensional (2D) profile view to the exact midsagittal plane were noted. Of six measurements, related to the fetal nose and jaws, the success rate and the intraobserver reproducibility between the 2D and the 3D multiplanar ultrasound were compared.

Results

In 81 (96.4%) cases we succeeded in obtaining a profile volume, 70% of the volumes being obtained within 10 min. It was possible to define by multiplanar mode the exact midsagittal plane in less than 1 min. The mean rotation necessary to obtain the exact midsagittal plane with 3D multiplanar mode was significantly larger around the y‐axis (11.9°) than around the z‐axis (4.3°) of the fetus. For between 5 and 12% of the six measurements under investigation it was not possible to obtain values with 2D ultrasound. However, 3D ultrasound made these measurements possible in at least one volume. The intraobserver reproducibility was higher with 3D multiplanar ultrasound than with 2D ultrasound, this difference being statistically significant for five of the six measurements.

Conclusions

3D multiplanar ultrasound improves the topographic depiction of the midsagittal profile view, enables correct measurement of anatomical details and improves intraobserver reproducibility. 3D multiplanar ultrasound is a powerful instrument for investigating the fetal profile. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
James Ensor's pigment use: artistic and material evolution studied by means of portable X‐ray fluorescence spectrometry
Authors: Snickt Geert Van der , Janssens Koen , Schalm Olivier , Aibéo Cristina , Kloust Hauke , Alfeld Matthias
Published: December 2009

In this paper, portable X‐ray fluorescence spectrometry (PXRF) was employed as a screening tool for determining and comparing the pigment use in a large series of paintings by the Belgian artist James Ensor (1860–1949). Benefits and drawbacks of PXRF as a method, and the instrument employed, are discussed from a practical, conservation and instrumental perspective. Regardless of several restrictions due to the set‐up and/or the analytical method, it appeared feasible to document the evolution with time in Ensor's use of inorganic pigments and to correlate this technical evolution with stylistic developments, Nevertheless, it became clear that a full identification of all materials present can only be done by means of the analysis of (cross‐sectioned) samples. Copyright © 2009 John Wiley & Sons, Ltd.