bluuebunny/crossref_metadata_2025 huggingface dataset:
A numerical analysis of a class of generalized Boussinesq‐type equations using continuous/discontinuous FEM
Authors: Lopes N.D. , Pereira P.J.S. , Trabucho L.
Published: July 2011

An improved class of Boussinesq systems of an arbitrary order using a wave surface elevation and velocity potential formulation is derived. Dissipative effects and wave generation due to a time‐dependent varying seabed are included. Thus, high‐order source functions are considered. For the reduction of the system order and maintenance of some dispersive characteristics of the higher‐order models, an extra O(μ2n+2) term (n  ∈  ℕ) is included in the velocity potential expansion. We introduce a nonlocal continuous/discontinuous Galerkin FEM with inner penalty terms to calculate the numerical solutions of the improved fourth‐order models. The discretization of the spatial variables is made using continuous P2 Lagrange elements. A predictor‐corrector scheme with an initialization given by an explicit Runge–Kutta method is also used for the time‐variable integration. Moreover, a CFL‐type condition is deduced for the linear problem with a constant bathymetry. To demonstrate the applicability of the model, we considered several test cases. Improved stability is achieved. Copyright © 2011 John Wiley & Sons, Ltd.
Coupled Navier–Stokes/molecular dynamics simulations in nonperiodic domains based on particle forcing
Authors: Steijl R. , Barakos G.
Published: July 2011

This paper focuses on coupling methods for hybrid Navier–Stokes/molecular dynamics (MD) simulations. The computational domain is split in a continuum flow region, where a finite‐volume discretisation of the Navier–Stokes equations is used, and one or more particle domains, where molecular level modelling of the flow is employed. The domains are defined with a partial overlap, in which the flow states are coupled through an exchange of the velocity components. For the steady flows considered, an under‐relaxed Newton iteration method is used to drive the coupled system to convergence. The main focus of the present work is on methods to impose nonperiodic boundary conditions on the particle domain(s). A particle forcing is applied in the direction normal to the particle domain boundary to impose the boundary normal velocity component. A novel aspect of the present work is the extension of this method to more general nonplanar particle domain boundaries. The main contribution of the paper is the development of a particle forcing method in the direction tangential to the domain boundary, which is based on the equivalent continuum‐flow boundary shear stresses along with an iterative forcing strength adjustment based on the extrapolated particle boundary velocity. Furthermore, an adaptation scheme is presented, which uses the finite‐volume flux residuals of the particle bin averaged velocity field as a truncation criterion for the iterative force‐update scheme. It is demonstrated that by comparing the residual reduction for the momentum equation in the nonhomogeneous directions during the molecular dynamics simulations with that for a homogeneous direction, the forcing iteration at which the statistical noise in the velocity field dominates the uncertainty in the forcing strength can be determined. At this point the iteration can be truncated. It is shown that with adaptive schemes of this type, the total number of MD evaluations required in a coupled Navier–Stokes/MD simulation can be reduced relative to a hybrid scheme with a fixed number of forcing‐strength updates. Copyright © 2011 John Wiley & Sons, Ltd.
Validating the URANS shear stress transport γ −Reθ model for low‐Reynolds‐number external aerodynamics
Authors: Counsil J. N. N. , Goni Boulama K.
Published: July 2011

A numerical investigation on low‐Reynolds‐number external aerodynamics was conducted using the transitional unsteady Reynolds‐averaged Navier–Stokes shear stress transport γ −Reθ model and the ANSYS‐CFX computational fluid dynamics suite. The NACA 0012 airfoil was exposed to chord‐based Reynolds numbers of 5.0 ×104, 1.0 ×105 and 2.5 ×105 at 0°, 4°and 8°angles of attack. Time‐averaged and instantaneous flow features were extracted and compared with fully turbulent shear stress transport results, XFLR5 panel e N method results, and published higher order numerical and experimental studies. The current model was shown to reproduce the complex flow phenomena, including the laminar separation bubble dynamics and aerodynamic performance, with a very good degree of accuracy. The sensitivity of the model to domain size, grid resolution and quality, timestepping scheme, and free‐stream turbulence intensity was also presented. In view of the results obtained, the proposed model is deemed appropriate for modelling low‐Reynolds‐number external aerodynamics and provides a framework for future studies for the better understanding of this complex flow regime. Copyright © 2011 John Wiley & Sons, Ltd.
Urinary pentosidine improves risk classification using fracture risk assessment tools for postmenopausal women
Authors: Tanaka Shiro , Kuroda Tatsuhiko , Saito Mitsuru , Shiraki Masataka
Published: July 2011

We investigated whether measurement of pentosidine, in addition to the conventional risk assessment tool, the Fracture and Immobilization Score (FRISC), improves early identification of fracture cases. A total of 765 postmenopausal Japanese women with baseline measurement of urinary pentosidine were followed in a hospital-based cohort study. Endpoints were incidence of vertebral fracture, incidence of long bone fracture, and incidence of long bone and vertebral fracture. To assess the effect of pentosidine on fracture risk, we fitted multivariate Cox regression models adjusted for age, body weight, diabetes mellitus, lumbar BMD, prior fracture, and presence of back pain. To explore potential nonlinear relationships, we fitted a multivariate generalized additive model. To assess the discriminatory power of pentosidine, we performed receiver operating characteristic analysis. The hazard ratios for a 1 SD increase in pentosidine were 1.18 (95% CI 1.05–1.33, p < 0.01) for vertebral fracture and 1.20 (95% CI 1.07–1.33, p < 0.01) for long bone and vertebral fractures. The relationship was approximately linear, and there was no indication of the presence of a threshold. The C statistics were 0.732 (95% CI 0.686–0.778) for the model with both pentosidine and the 10-year risk and 0.702 (95% CI 0.654–0.750) for the 10-year risk alone. Eighty-three subjects (11%) in the whole cohort were in the highest quartile of pentosidine, although their 10-year risks were less than 15% and included 17 incident vertebral fracture cases. Urinary pentosidine improves risk classification using conventional risk assessment tools. Optimal clinical strategies of diagnosis and treatment remain uncertain and in need of additional investigation. © 2011 American Society for Bone and Mineral Research
Optimal monitoring time interval between DXA measures in children
Authors: Shepherd John A , Wang Li , Fan Bo , Gilsanz Vicente , Kalkwarf Heide J , Lappe Joan , Lu Ying , Hangartner Thomas , Zemel Babette S , Fredrick Margaret , Oberfield Sharon , Winer Karen K
Published: July 2011

The monitoring time interval (MTI) is the expected time in years necessary to identify a change between two measures that exceeds the measurement error. Our purpose was to determine MTI values for dual-energy X-ray absorptiometry (DXA) scans in normal healthy children, according to age, sex, and skeletal site. 2014 children were enrolled in the Bone Mineral Density in Childhood Study and had DXA scans of the lumbar spine, total hip, nondominant forearm, and whole body. Measurements were obtained annually for seven visits from 2002 to 2010. Annualized rates of change were calculated by age and sex for all bone regions. A subgroup of 155 children ages 6 to 16 years (85 boys) had duplicate scans for calculation of scan precision. The bone mineral density (BMD) regions of interest included the spine, total body less head (TBLH), total hip, femoral neck, and one-third radius. Bone mineral content (BMC) was also evaluated for the spine and TBLH. The percent coefficient of variation (%CV) and MTI were calculated for each measure as a function of age and sex. The MTI values were substantially less than 1 year for the TBLH and spine BMD and BMC for boys ≤ 17 years and girls ≤ 15 years. The hip and one-third radius MTIs were generally 1 year in the same group. MTI values as low as 3 months were found during the peak growth years. However, the MTI values in late adolescence for all regions were substantially longer and became nonsensical as each region neared the age for peak bone density. All four DXA measurement sites had reasonable (< 1 year) MTI values for boys ≤ 17 years and girls ≤ 15 years. MTI was neither useful nor stable in late adolescence and young adulthood. Alternative criteria to determine scan intervals must be used in this age range. © 2011 American Society for Bone and Mineral Research
New heterocycles of 2,3‐diaryl‐substituted maleic hydrazides
Authors: Shih[1] Hsiencheng , Shih Renshuay J. , Carson Dennis A.
Published: July 2011

2,3‐Diaryl‐substituted maleic anhydrides were prepared by a modified one‐pot synthesis of Perkin condensation using mixed sodium salts of arylglyoxylic acid and arylacetic acid with acetic anhydride in 1,4‐dioxane. The treatment of these anhydrides with ammonium bicarbonate, or methanolic hydrazine, offered the corresponding 2,3‐diaryl‐substituted maleimides and maleic hydrazides (4,5‐diaryl‐substituted 1,2‐dihydropyridazine‐3,6‐dione), respectively. Evidence obtained from NMR, UV, and mass spectra suggest that 2,3‐diaryl‐substituted maleic hydrazides do not exhibit monolactim forms. Ring contraction of the diaryl‐substituted maleic hydrazide by nitrosation led to the formation of the corresponding maleimide. Interconversion between the corresponding maleic hydrazide and maleimide was observed following equilibrium reaction. Our experiment proposes that the chemistry of 2,3‐diaryl‐substituted maleic hydrazides rarely involves the function of ethylene moiety and resembles that of succinic hydrazine. J. Heterocyclic Chem.,(2011).
Design and synthesis of deuterated boceprevir analogs with enhanced pharmacokinetic properties
Authors: Morgan Adam J. , Nguyen Sophia , Uttamsingh Vinita , Bridson Gary , Harbeson Scott , Tung Roger , Masse Craig E.
Published: July 2011

As part of an ongoing effort to apply the Deuterated Chemical Entity Platform (DCE Platform™) to clinically validated drugs, the synthesis of deuterated analogs of the hepatitis C virus protease inhibitor boceprevir was carried out. The devised synthetic routes allowed for site‐selective deuterium incorporation with high levels of isotopic purity. Application of the DCE Platform™ to boceprevir enabled the identification of several deuterated analogs that display marked levels of in vitro metabolic stabilization. Most notably, analog 1g exhibits a near doubling of in vitro half‐life in human liver microsomal assays. The details of the convergent synthetic route to the boceprevir isotopologs and the results of the metabolic stability assays are described herein.
Synthesis of deuterium‐labeled simvastatin
Authors: Tian Lei , Tao Jie , Chen Liqin
Published: July 2011

This study describes the synthesis of deuterium‐labeled simvastatin. The stable isotope‐labeled compound was prepared starting from lovastatin in nine steps with 9% overall yield.
Radiosynthesis of [11C]SL25.1188 via [11C]CO2 fixation for imaging monoamine oxidase B
Authors: Vasdev Neil , Sadovski Oleg , Garcia Armando , Dollé Frédéric , Meyer Jeffrey H. , Houle Sylvain , Wilson Alan A.
Published: July 2011

Carbon‐11‐labelled (S)‐5‐methoxymethyl‐3‐[6‐(4,4,4‐trifluorobutoxy)benzo[d]isoxazol‐3‐yl]oxazolidin‐2‐[11C]‐one ([11C]SL25.1188), a promising reversibly binding radiotracer for imaging central monoamine oxidase B, was rapidly prepared via an intramolecular cyclization reaction in an automated one‐pot procedure directly from [11C]CO2, thereby precluding the use of [11C]COCl2. Formulated [11C]SL25.1188 was isolated in 12 ± 1% uncorrected radiochemical yield, based on starting [11C]CO2, with a specific activity of 37 ± 2 GBq/µmol at the end of synthesis (30 min; n = 3). Radiochemical and enantiomeric purities were both >99%. The methodology described herein offers an efficient production of [11C]SL25.1188 at ambient temperature and is suitable for human imaging studies.
The spatial and temporal sampling errors inherent in low resolution radar estimates of rainfall
Authors: Shucksmith P. E. , Sutherland‐Stacey L. , Austin G. L.
Published: July 2011

The errors introduced into radar estimates of rainfall by making observations at spatial and temporal resolutions that are coarse compared with precipitation systems' characteristic length and time scales are explored in this study. High resolution (200 m, 50 s) X‐band radar data from 48 mid‐latitude precipitation events are downgraded progressively in spatial and temporal resolution so that estimates of this sampling error can be made by comparing 10 min rainfall accumulations of this data to accumulations calculated from the original high resolution data. The analysis shows these errors to be of significant magnitude. For 2 km and 5 min sampling, this error varies from 17 to 64% of the mean rainfall accumulation. A relationship is shown between the error introduced from the reduction in spatial resolution and the characteristic length scale of the precipitation system along with a metric of precipitation intensity. Copyright © 2011 Royal Meteorological Society
Gene expression response of mouse lung, liver and white adipose tissue to β‐carotene supplementation, knockout of Bcmo1 and sex
Authors: van Helden Yvonne G. J. , Godschalk Roger W. L. , von Lintig Johannes , Lietz Georg , Landrier Jean‐Francois , Luisa Bonet M. , van Schooten Frederik J. , Keijer Jaap
Published: July 2011

Scope: Little information is available on differences, commonalities and especially interactions in overall gene expression responses as a result of diet, differences in sex (male and female) and effects induced by differences in metabolism. Moreover, it is unknown whether such effects are tissue specific.

Methods and results: We investigated the gene expression effects induced by β‐carotene (BC) supplementation, knockout of β‐carotene 15,15′‐monooxygenase 1 (Bcmo1) and differences between male and female mice in lung, liver and inguinal white adipose tissue (iWAT). Unsupervised principal component analysis showed that lung gene expression was most affected by knockout of Bcmo1. Liver was most affected by knockout of Bcmo1 and differences in sex. iWAT was most affected by differences in sex. Hardly any genes were commonly influenced by BC among the three tissues. The effect of BC supplementation and knockout of Bcmo1 were relatively sex specific, especially in iWAT.

Conclusion: These data demonstrate that gene expression differences induced by BC are limited to the tissue and sex that is analyzed, and that differences in metabolism induced by for example single nucleotide polymorphisms, should be taken into account as much as possible. Moreover, our results indicate that translation from one tissue to the other should be done with caution for any nutritional intervention.
Polymorphisms of estrogen receptors alpha and beta in idiopathic, infertile Brazilian men: A case–control study
Authors: Bianco Bianca , Peluso Carla , Gava Marcello Machado , Ghirelli‐Filho Milton , Lipay Monica Vannucci Nunes , Lipay Marco Aurélio , Christofolini Denise Maria , Barbosa Caio Parente
Published: July 2011

Estrogen plays an important role in the human reproductive system and its action is mediated mainly by two specific receptors: α (ERα) and β (ERβ). There are polymorphic variants in both ER genes, and studies showed their association with reproductive outcomes. We aimed to determine the distribution of ERα and ERβ gene polymorphisms in idiopathic, infertile Brazilian patients in a case–control study comprising 187 idiopathic, infertile Brazilian men with nonobstructive azoospermia (NOA, n = 78) or severe oligozoospermia (SO, n = 109) and 216 fertile men. Detection of ERα (PvuII and XbaI) and ERβ (AluI and RsaI) gene polymorphisms were performed using TaqMan PCR. The results were analyzed statically, and a P‐value < 0.05 was considered significant. Single‐marker analysis revealed that neither PvuII nor XbaI polymorphisms of the ERα gene were associated either with NOA group (P = 0.662 and P = 0.527, respectively) or SO group (P = 0.777 and P = 1.0, respectively). Regarding ERβ polymorphisms, no statistical difference was observed between the AluI polymorphism and NOA group compared to controls (P = 1.0) or between SO group and controls (P = 0.423). We found similar results with the RsaI polymorphism. Statistical analysis did not reveal a difference between NOA (P = 0.740) and SO (P = 0.920) groups compared to controls. Combined genotypes of ERα and ERβ polymorphisms did not identify a haplotype associated with idiopathic infertility. Thus, in the Brazilian population, genetic variations in both estrogen receptors alpha (PvuII and XbaI) and beta (AluI and RsaI) were not relevant to idiopathic infertility. Mol. Reprod. Dev. 78:665–672, 2011. © 2011 Wiley‐Liss, Inc.
Presence of cleaved caspase 3 in swine embryos of different developmental capacities produced by parthenogenetic activation
Authors: Coutinho Ana Rita S. , Assumpção Mayra E.O. , Bordignon Vilceu
Published: July 2011

This study assessed the presence of cleaved caspase 3 (CC3) during the in vitro development of swine embryos produced by parthenogenetic activation (PA). Embryos with high and low capacity to develop into blastocysts and the exposure to a caspase inhibitor (z‐DEVD‐fmk) were used to investigate the effect of CC3 on embryo development. The blastocyst rate (64.3% vs. 16.4%) and the average number of nuclei per blastocyst (39.7 vs. 19.8) were significantly higher (P < 0.05) in early‐ (before 24 hr) compared to late‐ (between 24 and 48 hr) cleaving embryos after PA. CC3 was mainly detected in the cytoplasm of Day‐2 and ‐4 embryos, but was primarily localized in the nucleus of Day‐5 and ‐6 embryos. The fluorescence signal for CC3 relative to negative controls was significantly higher (P < 0.05) in early‐ (2.42‐fold) compared to late‐cleaving (1.39‐fold) embryos at Day 2 of culture. Treatment with z‐DEVD‐fmk during the first 24 or 48 hr of the culture period resulted in more embryos developing into blastocysts compared to the control group (55.8% and 55.1% vs. 37%, respectively;P < 0.05). This study confirmed the presence of CC3 in PA embryos from the two‐cell to the blastocyst stage, and revealed that CC3 cellular‐localization changed during embryo development. CC3 was shown to be more abundant in early‐cleaving and more developmentally competent embryos compared to late‐cleaving and less developmentally competent embryos. The inhibition of caspase activity at the beginning, but not at the end, of the culture period affected development of PA embryos. Mol. Reprod. Dev. 78:673–683, 2011. © 2011 Wiley‐Liss, Inc.
PMSW: a passive monitoring system in wireless sensor networks
Authors: Xu Xianghua , Wan Jian , Zhang Wei , Tong Chao , Wu Changhua
Published: July 2011

Network passive monitoring is an important method in debugging and analyzing wireless sensor networks. The passive monitoring method for wireless sensor networks (WSN) has the following problems: monitoring traces are incomplete and contain only limited information because some packets may be misheard; how to infer implicit information about network protocol behavior and how to detect network events from incomplete traces are challenging issues in passive monitoring system. To resolve the above issues, we propose the use of time tuning in trace merging and a finite state machine for inferring missing packets, implicit information and network event detection. (1) In order to enhance the integrity of traces, we propose clock‐adjusting strategies including clock fine‐tuning and clock self‐adjustment to solve clock drifting in trace merging. (2) For inference of missing packets and implicit information, we devise and implement a finite state machine to infer missing packets and packet receiving state for multi‐hop network protocols. (3) For network event detection, we propose an XML‐based description of event rule and network event visualization methods. These methods are implemented in PMSW (passive monitoring system for WSN). We verify the accuracy of merging and inference modules with monitoring traces in the Collect Tree Protocol sensor network. Experiments show that the finite state machine can infer 40–60% of missing packets and more than 90% of the receiving state of data packets, when the trace has more than 50% of the data packets captured in the network. Copyright © 2011 John Wiley & Sons, Ltd.
A random obstacle‐based mobility model for delay‐tolerant networking
Authors: Wu Di , Li Juanjuan , Liu Jiangchuan
Published: July 2011

When evaluating a new protocol in the network, it is important to use a realistic mobility model to reflect the actual performance of a mobile system. Only the realistic mobility model can better mimic the reality and get more reliable data. However, most existing mobile models of delay‐tolerant networking (DTN) move randomly or on the road according to some rules under the environment without obstacles. These mobile models, without considering the impact of obstacles on the node, do not accord with the fact. To address this problem, we propose a random obstacle‐based mobility model (ROM) aimed at better simulating the real trajectory of a human for DTN in the presence of obstacles. In this model, we can place arbitrary‐shape obstacles in accordance with any actual scene, as well as considering the influence of obstacles on the signal. The mobile path of a node calculated by this node is the shortest path to the destination avoiding certain types of obstacles. In addition, the propagation model contains the attenuation of the signal due to the existence of obstacles. As a result, we have developed a complete obstacle mobility model which is more suitable for studying the performance of the network. We augment the ‘opportunistic network environment’ (ONE) simulator of DTN with required extensions and show that characteristics of the DTN are very different using the new model than it is under models that ONE currently provides. Copyright © 2011 John Wiley & Sons, Ltd.
Perceptual differences in corporate philanthropy motives: a South Korean study
Authors: Lee Hanjoon , Lancendorfer Karen M. , Reck Robert
Published: July 2011

We studied what types of motives South Korean consumers and corporate giving officers attributed to corporate philanthropy (CP). Results showed gaps between consumers and corporate giving officers in that consumers more firmly believed corporations conducted CP for profit‐driven motives than did corporate giving officers, whereas the corporate giving officers more strongly perceived that corporations engaged in CP for altruistic motives. Based on these findings, we discuss managerial implications for practitioners. Copyright © 2011 John Wiley & Sons, Ltd.
Reference output tracking control for a flexible air‐breathing hypersonic vehicle via output feedback
Authors: Li Hongyi , Wu Ligang , Gao Huijun , Hu Xiaoxiang , Si Yulin
Published: July 2011

This paper addresses the problem of reference output tracking control for the longitudinal model of a flexible air‐breathing hypersonic vehicle (FAHV) by utilizing the output feedback control approach. The dynamic characteristics of the FAHV along with the aerodynamic effects of hypersonic flight make the flight control of such systems highly challenging. Moreover, there exist some intricate couplings between the engine and flight dynamics as well as complex interaction between rigid and flexible modes in the longitudinal model. These couplings bring difficulty to the flight control design for the intractable hypersonic vehicle systems. This paper deals with the problem of reference output tracking control for the longitudinal model of the FAHV. By utilizing the trim condition information including the state of altitude, velocity, angle of attack, pitch angle, pitch rate and so on, the linearized model is established for the control design objective. Then, the reference output velocity and altitude tracking control design problem is proposed for the linearized model. The flexible models of the FAHV system are hardly measured because of the complex dynamics and the strong couplings of the FAHV. Thus, by using only limited flexible model information, the reference output tracking performance analysis criteria are obtained via Lyapunov stability theory. Then, based on linear matrix inequality optimization algorithm, the static output feedback controller is designed to stabilize the closed‐loop systems, guarantee a certain bound for the closed‐loop value of the cost function, and can make the control output achieve the reference velocity and altitude tracking performance. Subsequently, the condition of dynamic output feedback controller synthesis is given in terms of linear matrix inequalities and a numerical algorithm is developed to search for a desired dynamic output feedback controller which minimizes the cost bound and obtains the excellent reference altitude and velocity tracking performance simultaneously. The effectiveness of the proposed reference output tracking control method is demonstrated in simulation part. Furthermore, the superior reference velocity and altitude performance commands could be achieved via using static and dynamic output feedback controllers under lacking some unmeasured flexible states information in the measurement output vector. Copyright © 2011 John Wiley & Sons, Ltd.
Adsorption properties of thermally stable and biologically active polyurea: its synthesis and spectral aspects
Authors: Hasnain Sumaiya , Zulfequar M. , Nishat Nahid
Published: July 2011

Novel polymer metal complexes were prepared by the condensation polymerization of a polymeric ligand with transition metal ions of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The polymeric ligand was prepared by the addition polymerization of urea with toluene 2,4‐diisocyanate in 1:1 molar ratio. The polymeric ligand and its polymer metal complexes were characterized by elemental analysis, Fourier transform infrared spectroscopy, 13C‐NMR, and1H‐NMR (nuclear magnetic resonance). The geometry was determined by electronic spectra and magnetic moment measurement. Thermogravimetric analysis (TGA) was utilized to find out the degradation process of the polyurea ligand and the polymer metal complexes. The TGA data revealed that all the metal‐containing polyureas are much more thermally stable than the corresponding polyurea ligand. The surface morphology of the polyurea ligand and cobalt(II)‐containing polyureas was determined by scanning electron micrographs. The antibacterial and antifungal activities of all the synthesized polymers were investigated against Staphylococcus aureus, Escherichia coli, and Bacillus subtilis (bacteria) and Aspergillus niger, Candida albicans, and Aspergillus flavus (fungi). These compounds show remarkably good biocidal activities, which were enhanced after complexation with the metal. Batch adsorption studies of the ligand were carried out for malachite green dye, and the polyurea ligand was found to be a good adsorbent for this dye. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and characterization of anhydrous conducting polyimide/ionic liquid complex membranes via a new route for high‐temperature fuel cells
Authors: Deligöz Hüseyin , Yılmazoğlu Mesut , Yılmaztürk Serpil , Şahin Yavuz , Ulutaş Kemal
Published: July 2011

The paper deals with the synthesis and characterization of a new series of anhydrous conducting acid‐doped complex membranes based on polyimide (PI) and ionic liquid (IL) for high‐temperature fuel cells via a new route. For this purpose, three imidazolium‐based ILs (RIm+BF4−) with different alkyl chain lengths (R=methyl, ethyl, and butyl) are added into polyamic acid (PAA) intermediate prepared from the reaction of benzophenonetetracarboxylic dianhydride and diaminodiphenylsulfone in different –COOH/imidazolium molar ratios (n = 0.5, 1, and 2). Then, the thermally imidized complex membrane was doped with H2SO4. The conductivities of acid‐doped PI/IL complex membranes prepared by taking n of 1 are found to be in the range of 10−4−10−5 S cm−1 at 180°C, whereas the acid‐free PI/IL complex membranes show the conductivity at around 10−9−10−10 S cm−1. Thermogravimetric analysis results reveal that the acid‐doped PI/IL complex membranes are thermally stable up to 250°C. Dynamic mechanical analysis results of the acid‐doped ionically interacted complex membrane show that the mechanical strengths of the PI/IL complex membranes including 1‐methyl imidazolium tetrafluoroborate (MeIm‐BF4) and 1‐ethyl 3‐methyl imidazolium tetrafluoroborate (EtIm‐BF4) are comparable with those of pristine PI until 200°C. Furthermore, it can be clearly emphasized that the ionic interaction between carboxylic acid groups of PAA's and IL's cations offers a positive role in long‐term conductivity stability by preventing the IL migration at high temperatures. On the other hand, preliminary methanol permeability tests of the acid‐doped membranes show that they can also be considered as an alternative for direct methanol fuel cells. Copyright © 2011 John Wiley & Sons, Ltd.
Polyurethane (urea)/polyacrylates interpenetrating polymer network (IPN) adhesives for low surface energy materials
Authors: Li Minrui , Zheng Zhen , Liu Shujuan , Su Yuezeng , Wei Wei , Wang Xinling
Published: July 2011

On the basis of the polymerization of the acrylate phase catalyzed by the oxidation of trialkylborane at room temperature, a series of polyurethane (urea)/polyacrylates adhesives with interpenetrating polymer network structure (IPNS) was synthesized. The crosslinking polyurethane (urea) phase was synthesized by the reaction between polymer diamine or triol and isocyanate. The resulting IPN adhesives as a function of the polyurethane (urea) or 2‐hydroxylethyl acrylate terminated polyurethane (HEA‐PU) (crosslinking agent of acrylate phase) content were explored. The adhesive morphology took on the IPNS that manifested as a finely dispersed polyurethane (urea) phase in the acrylate phase. Excellent adhesion to low surface energy materials was achieved within a wide range of polyurethane (urea) contents. The IPN adhesives also displayed better flexibility than polyacrylate adhesives with HEA‐PU as a crosslinking agent. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and properties of novel polytriazoleimides derived from 1,2,3‐triazole‐containing diamines and aromatic dianhydrides
Authors: E Yanpeng , Wan Liqiang , Zhou Xiao'an , Huang Farong , Du Lei
Published: July 2011

A new kind of 1,2,3‐triazole‐containing aromatic diamines were synthesized by the Cu(I)‐catalyzed 1,3‐dipolar cycloaddition reaction. These diamines were employed to synthesize a series of novel polytriazoleimides (PTAIs) by polycondensation with various aromatic dianhydrides in N,N‐dimethylacetamide (DMAc) via the conventional two‐step method. The obtained polyimides were characterized by Fourier transform infrared, hydrogen‐1 nuclear magnetic resonance, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis techniques. The results show that the PTAIs are soluble in most of strong polar solvents and have inherent viscosity values of 0.47–0.68 dl/g (DMAc). PTAI films have tensile strengths of 60.6–102.6 MPa and elongations at breakage of 3.0–4.1%, glass transition temperatures (Tg) of 208–262°C, and decomposition temperatures (at 5% weight loss) of 368–401°C in N2 atmosphere, which depend on the structure of the polymers. The PTAIs also exhibit good adhesion to copper and gas separation properties. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of compounding procedure on morphology and crystallization behavior of isotactic polypropylene/high‐density polyethylene/carbon black ternary composites
Authors: Yin Chao‐Lu , Liu Zheng‐Ying , Gao Yong‐Juan , Yang Ming‐Bo
Published: July 2011

The effect of compounding procedure on morphology and crystallization behavior of isotactic polypropylene/high‐density polyethylene/carbon black (iPP/HDPE/CB) composite was investigated. iPP/HDPE/CB composites were prepared by four compounding procedures (A: iPP + HDPE + CB; B: iPP/HDPE + CB; C: HDPE/CB + iPP; D: iPP/CB + HDPE). Scanning electron microscopy observation showed that CB particles are mainly distributed in HDPE in all composites, and the phase morphology of composites was obviously affected by a compounding procedure. The size of the HDPE/CB domains in the composites prepared by procedures A and D decreased with the increase in CB content, whereas that of HDPE/CB in the composites prepared by procedures B and C rarely changed with the increase in CB content. The crystallization behaviors of the composites were significantly affected by their phase morphology, which resulted from the variation of compounding procedure. The isothermal crystallization rate of iPP in the composites prepared by procedures A and D was obviously increased, which may originate from the small HDPE/CB droplets dispersed in the iPP phase. The non‐isothermal crystallization curves of composites prepared by procedure D represented two peaks because the iPP component in these composites had the fastest crystallization rate, whereas the curves of composites prepared by other compounding sequences only exhibited one peak. Moreover, the crystallinity of HDPE almost increased by one time with the incorporation of only 1 phr CB because the CB particles selectively located in the HDPE phase, and the crystallinity of HDPE decreased with the further increase of CB content because of the strong restriction of CB on the HDPE chains. Copyright © 2011 John Wiley & Sons, Ltd.
Electrochemical characterization of hydrogels for biomimetic applications
Authors: Peláez L. , Romero V. , Escalera S. , Ibragimova S. , Stibius K. , Benavente J. , Hélix‐Nielsen C.
Published: July 2011

Hydrogels are increasingly being recognized as having potential in bio‐compatible applications. In previous work, we investigated the feasibility of poly(ethylene glycol)‐dimethacrylate (PEG‐1000‐DMA) and poly(ethylene glycol)‐diacrylate (PEG‐400‐DA) polymerized using either a chemical initiator (C) or a photoinitiator (P) to encapsulate and stabilize biomimetic membranes for novel separation technologies or biosensor applications. In this paper, we have investigated the electrochemical properties of the hydrogels used for membrane encapsulation. Specifically, we studied the crosslinked hydrogels by using electrochemical impedance spectroscopy (EIS), and we demonstrated that chemically crosslinked hydrogels had lower values for the effective electrical resistance and higher values for the electrical capacitance compared with hydrogels with photoinitiated crosslinking. Transport numbers were obtained using electromotive force measurements and demonstrated that at low salt concentrations, both PEG‐400‐DA‐C and PEG‐400‐DA‐P hydrogels presented an electropositive character whereas PEG‐1000‐DMA‐P was approximately neutral and PEG‐1000‐DMA‐C showed electronegative character. Sodium transport numbers approached the bulk NaCl electrolyte value at high salt concentrations for all hydrogels, indicating screening of fixed charges in the hydrogels. The average salt diffusional permeability 〈Ps〉 and water permeability 〈Pw〉 were found to correlate with EIS results. Both PEG‐1000‐DMA‐C and PEG‐400‐DA‐C had higher 〈Ps〉 and 〈Pw〉 values than PEG‐1000‐DMA‐P and PEG‐400‐DA‐P hydrogels. In conclusion, our results show that hydrogel electrochemical properties can be controlled by the choice of polymer and type of crosslinking used and that their water and salt permeability properties are congruent with the use of hydrogels for biomimetic membrane encapsulation. Copyright © 2011 John Wiley & Sons, Ltd.
Gain‐of‐function mutant p53 but not p53 deletion promotes head and neck cancer progression in response to oncogenic K‐ras
Authors: Acin Sergio , Li Zhongyou , Mejia Olga , Roop Dennis R , El‐Naggar Adel K , Caulin Carlos
Published: July 2011

Mutations in p53 occur in over 50% of the human head and neck squamous cell carcinomas (SCCHN). The majority of these mutations result in the expression of mutant forms of p53, rather than deletions in the p53 gene. Some p53 mutants are associated with poor prognosis in SCCHN patients. However, the molecular mechanisms that determine the poor outcome of cancers carrying p53 mutations are unknown. Here, we generated a mouse model for SCCHN and found that activation of the endogenous p53 gain‐of‐function mutation p53$^{\rm{R172H}}$, but not deletion of p53, cooperates with oncogenic K‐ras during SCCHN initiation, accelerates oral tumour growth, and promotes progression to carcinoma. Mechanistically, expression profiling of the tumours that developed in these mice and studies using cell lines derived from these tumours determined that mutant p53 induces the expression of genes involved in mitosis, including cyclin B1 and cyclin A, and accelerates entry in mitosis. Additionally, we discovered that this oncogenic function of mutant p53 was dependent on K‐ras because the expression of cyclin B1 and cyclin A decreased, and entry in mitosis was delayed, after suppressing K‐ras expression in oral tumour cells that express p53$^{\rm{R172H}}$. The presence of double‐strand breaks in the tumours suggests that oncogene‐dependent DNA damage resulting from K‐ras activation promotes the oncogenic function of mutant p53. Accordingly, DNA damage induced by doxorubicin also induced increased expression of cyclin B1 and cyclin A in cells that express p53$^{\rm{R172H}}$. These findings represent strong in vivo evidence for an oncogenic function of endogenous p53 gain‐of‐function mutations in SCCHN and provide a mechanistic explanation for the genetic interaction between oncogenic K‐ras and mutant p53. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The Most Frequently Encountered Volatile Contaminants of Essential Oils and Plant Extracts Introduced During the Isolation Procedure: Fast and Easy Profiling
Authors: Radulović Niko S. , Blagojević Polina D.
Published: July 2011

Introduction

Unfortunately, contaminants of synthetic/artificial origin are sometimes identified as major constituents of essential oils or plant extracts and considered to be biologically active native plant metabolites.

Objective

To explore the possibility of early recognition and to create a list of some of the most common semi‐volatile contaminants of essential oils and plant extracts.

Methodology

Detailed GC and GC‐MS analyses of the evaporation residues of six commercially available diethyl ethers and of a plastic bag hydrodistillate were performed. Average mass scans of the total ion chromatogram profiles of the analysed samples were performed.

Results

Almost 200 different compounds, subdivided into two groups, were identified in the analysed samples: (i) compounds that could be only of a synthetic/artificial origin, such as butylated hydroxytoluene and o‐phthalic acid esters, i.e. requiring exclusion from the list of identified plant constituents; (ii) compounds possibly of synthetic and/or natural plant origin, i.e. compounds derived from the fatty acid metabolism or products of anaerobic intracellular/microbial fermentation. Average mass scans of the total ion chromatogram profiles provide meaningful and convenient information on uncovering important solvent‐derived contamination.

Conclusion

A database of the most common semi‐volatile contaminants of essential oils and plant extracts has been generated that provides information on the likelihood of rejection or acceptance of contaminants as possible plant constituents. The suggested average mass scan approach enables fast and easy profiling of solvents, allowing even inexperienced researchers to pinpoint contaminants. Copyright © 2011 John Wiley & Sons, Ltd.
Preparative Isolation, Fast Centrifugal Partition Chromatography Purification and Biological Activity of Cajaflavanone from Derris ferruginea Stems
Authors: Morel Sylvie , Landreau Anne , Nguyen Van Hung , Derbré Séverine , Grellier Philippe , Le Pape Patrice , Pagniez Fabrice , Litaudon Marc , Richomme Pascal
Published: July 2011

Introduction

The Derris genus is known to contain flavonoid derivatives, including prenylated flavanones and isoflavonoids such as rotenoids, which are generally associated with significant biological activity.

Objective

To develop an efficient preparative isolation procedure for bioactive cajaflavanone.

Methodology

Fast centrifugal partition chromatography (FCPC) was optimised to purify cajaflavanone from Derris ferruginea stems in a single step as compared to fractionation from the cyclohexane extract by successive conventional solid–liquid chromatography procedures. The purification yield, purity, time and solvent consumption per procedure are described. The anti‐fungal, anti‐bacterial, anti‐leishmanial, anti‐plasmodial, anti‐oxidant activities and the inhibition of advanced glycation end‐products (AGEs) by cajaflavanone accumulation are described.

Results

FCPC enabled cajaflavanone purification in a single separation step, yielding sufficient quantities to perform in vitro biological screening. Interestingly, cajaflavanone had an inhibitory effect on the formation of AGEs, without displaying any in vitro anti‐oxidant activity.

Conclusion

A simple and efficient procedure, in comparison with other preparative methods, for bioactive cajaflavone purification has been developed using FCPC. Copyright © 2011 John Wiley & Sons, Ltd.
Quantification of free fetal DNA in multiple pregnancies and relationship with chorionicity
Authors: Attilakos George , Maddocks Deborah G. , Davies Teresa , Hunt Linda P. , Avent Neil D. , Soothill Peter W. , Grant Simon R.
Published: July 2011

Objective

Free fetal DNA (ffDNA) in the maternal plasma appears to originate mainly from the trophoblast. We tested the hypothesis that ffDNA concentration is increased in multiple pregnancies where trophoblastic mass has been shown to be increased.

Methods

Quantitative real‐time PCR was used to measure the plasma concentration of DYS14 in singleton and twin pregnancies with one or two male fetuses. Royston and Wright's regression method was used to relate ffDNA to gestational age in singleton controls; z‐scores were calculated for the multiple pregnancy subgroups.

Results

Fifty‐five singleton and 65 twin pregnancies (36 with one and 29 with two male fetuses) were analysed. There was significantly higher ffDNA concentration in twin pregnancies with two male fetuses compared with pregnancies with one male fetus. In cases with two male fetuses, there was no statistically significant difference between monochorionic and dichorionic pregnancies.

Conclusions

There is higher ffDNA concentration in multiple pregnancies, and this must be taken into account for future quantitative ffDNA applications. Copyright © 2011 John Wiley & Sons, Ltd.
Birth outcomes among women exposed to neuraminidase inhibitors during pregnancy
Authors: Svensson Tobias , Granath Fredrik , Stephansson Olof , Kieler Helle
Published: July 2011

Purpose

To compare birth outcomes between women exposed and unexposed to the antiviral medications oseltamivir or zanamivir during pregnancy.

Methods

This was an observational cohort study including women who gave birth to singletons in Sweden 2005–2007 and their infants. We obtained information from the national health registers and evaluated risks of low Apgar score, small for gestational age (SGA), low birth weight, preterm delivery, congenital malformations, birth‐related death (stillbirth and neonatal death combined), and neonatal morbidity by conditional logistic regression. The unexposed [n = 860] were matched to the exposed [n = 86] by birth year and fetal gender.

Results

A total of 81 women filled a prescription with oseltamivir only, 2 with zanamivir, and 3 with both oseltamivir and zanamivir. Compared with the unexposed infants, the exposed ones had higher risks of late transient hypoglycemia (crude OR = 4.00, 95%CI: 1.26–12.76). There were no statistical increased risks of low Apgar score, congenital malformations, SGA, low birth weight, preterm birth, or birth‐related death. Adjusting for maternal age, parity, smoking, and body mass index had minor effects on the results. None of the women exposed to oseltamivir or zanamivir had been admitted to hospital for influenza during their pregnancy.

Conclusions

Except for an increased risk of late transient hypoglycemia, we found no increased risks of adverse birth outcomes among infants exposed to neuraminidase inhibitors in fetal life compared with the unexposed. Copyright © 2011 John Wiley & Sons, Ltd.
Irish Medicines Board safety warnings: do they affect prescribing rates in primary care?
Authors: Musleh S. , Kraus S. , Bennett K. , Zaharan N. L.
Published: July 2011

Purpose

To examine the impact of safety warnings issued between 2005 and 2007 by the Irish Medicines Board (IMB) on the rate of prescribing of clopidogrel, co‐amoxiclav, celecoxib and haloperidol by primary care physicians in the General Medical Services (GMS) scheme across Ireland.

Methods

This study was performed using the Irish Health Service Executive–Primary Care Reimbursement Services national prescribing database. Rate of prescribing per 1000 GMS population was calculated for each of the 12  months before and after the IMB warnings were issued to physicians. A segmented regression analysis was used to examine the change in level and trend in prescribing rates before and after the IMB warnings. Regression coefficients are presented with SEs. Significance at p < 0.05 was assumed. SPSS 16 and SAS were used for statistical analysis.

Results

Prescribing of clopidogrel continued to rise in both genders following the warning. This increase was slightly higher in male patients. The prescribing of co‐amoxiclav showed seasonal variation with significant autocorrelation. The rate of prescribing of celecoxib declined approximately 4  months prior to the IMB warning. A significant decrease in the level and trend of the rate of prescribing of celecoxib was observed with evident discontinuity. The IMB warning had no significant effect on the level of trend in the prescribing of haloperidol, suggesting no discontinuity.

Conclusions

Results indicate that the IMB safety warnings had inconsistent effects on the rate of prescribing of drugs considered. Copyright © 2011 John Wiley & Sons, Ltd.