bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on metabonomic characteristics of human lung cancer using high resolution magic‐angle spinning 1H NMR spectroscopy and multivariate data analysis
Authors: Chen Wenxue , Zu Yukun , Huang Qi , Chen Fener , Wang Guifang , Lan Wenxian , Bai Chunxue , Lu Shaohua , Yue Yong , Deng Feng
Published: April 2011

Lung cancer causes serious health problems. Clinical diagnosis of lung cancer relies on histopathological evalution of tissue specimen. However, extensive knowledge of the metabolic biochemistry of tumors can potentially provide important information for accurate diagnosis of lung cancer. High resolution magic‐angle spinning NMR spectroscopy has emerged and be widely acknowledged as an excellent tool in investigating tissue metabolism. Moreover, the combination of high resolution magic‐angle spinning NMR technique and multivariate data analysis has become an important metabonomics platform for studying the intact biological tissues. This study reported the metabonomic characteristics of 51 lung tissues from 17 patients with lung cancer using the high resolution magic‐angle spinning 1H NMR spectroscopy and the multivariate data analysis methods including principal component analysis and orthogonal partial least squares‐discriminant analysis. Clear differences among the metabonomic characteristics of lung cancer tissues at various sites were disclosed. Compared with the adjacent noninvolved tissues, the lung cancer tissues had significantly high levels of aspartate, phosphocholine, glycerophosphocholine and lactate but significantly low levels of glucose and valine. Furthermore, significantly positive (or negative) correlations were observed between the levels of some metabolites such as lactate, fatty acids, valine, phosphocholine, and glycerophosphocholine. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Statistical assessment of non‐Gaussian diffusion models
Authors: Kristoffersen Anders
Published: April 2011

In human brain diffusion measurements, there are deviations from monoexponential signal decay at high values of the diffusion‐weighting factor b. This is known as non‐Gaussian diffusion and can provide novel kinds of image contrast. We evaluated quantitatively the goodness‐of‐fit of five popular diffusion models. Because of the Rician signal distribution and physiological noise, the measurement errors are unknown. This precludes standard χ2 testing. By repeating the measurement 25 times, the errors were estimated. Hypothesis testing based on the residual after least squares curve fitting was then carried out. Systematic errors originating from the Rician signal bias were eliminated in the fitting procedure. We performed diffusion measurements on four healthy volunteers with b‐values ranging from 0 to 5000 s/mm2. The data were analyzed voxelwise. The null hypothesis of a given model being adequate was rejected, if the residual after fitting exceeded a limit that corresponds to a significance level of 1%. The fraction of rejected voxels depended strongly on the number of free model parameters. The rejected fraction was: monoexponential model with two parameters, 94%; statistical model with three parameters, 29%; stretched exponential model with three parameters, 35%; cumulant model with three parameters, 48%; cumulant model with four parameters, 11%; biexponential model with four parameters, 2.9%. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Maternal concern, social support, and health‐related quality of life across childhood
Authors: Coyle Susan B.
Published: April 2011

Mothers play a critical role in child and family health yet little is known about the concerns and health‐related quality of life (HRQOL) of mothers beyond early childhood. The purpose of this study of 234 mothers of children up to 18 years of age was to examine relationships among maternal concern, social support, and HRQOL. Mothers reported a low level of concern, but concern was a significant predictor of HRQOL. The health burden for mothers was demonstrated primarily in the mental health components of HRQOL. The effect of social support was minimal and limited to the mental health domain of HRQOL. Results suggest regular assessment of maternal concerns and mental health coupled with education regarding coping strategies to support HRQOL for all mothers. © 2011 Wiley Periodicals, Inc. Res Nurs Health 34:297–309, 2011
Civic engagement in the policy process in Hong Kong: Change and continuity
Authors: Cheung Peter T. Y.
Published: April 2011

The role of civic engagement is particularly noteworthy in quasi‐democratic regimes like Hong Kong because it can potentially confer some degree of legitimacy on politics and the policy process. This article examines older and more recent means of civic engagement in the policy process in Hong Kong. The concepts of civic engagement and public participation are addressed, leading into discussions of the established mechanisms for public participation, the pressure on the government's approach to civic engagement since 2003, and the politics of civic action on heritage preservation and urban planning. Hong Kong's experience indicates that in a quasi‐democratic polity the main channels for public participation in the policy process are often dominated by pro‐government business and professional elites, and more participatory mechanisms are only gradually introduced after civic action by civil society groups, as reflected in the recent politics over heritage and planning. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and photopatterning of Langmuir–Blodgett (LB) films of a novel copolymer containing swallow‐tailed double naphthalene groups
Authors: Li Tiesheng , Xu Wenjian , Tang Caiqin , Zhang Min , Wu Yangjie , Miyashita Tokuji
Published: April 2011

A new series of copolymer poly(N‐hexadecylmethacrylamide‐co‐dinaphthalen‐2‐yl 2‐allylmalonate) poly(HDMA‐co‐DNAM)s containing swallow‐tailed double naphthyl groups and long alkyl group were designed and synthesized. The behavior of copolymer molecular arranging on water surface, patterning properties of copolymer LB films, and photochemical reactions in ultrathin film were investigated. The poly(HDMA‐co‐DNAM)s could form a stable, well‐defined molecular orientation Langmuir monolayer at air/water interface. The polymer main chain was lying flat on water surface and the side chains attached to the main chain stretching out at the angle of about 50°. The results obtained showed that a well‐ordered layer‐by‐layer structure was successfully controlled in LB films, in which most of naphthyl groups in poly(HDMA‐co‐DNAM)s LB films were in dimer and the copolymer LB films were decomposed hardly upon irradiation of deep UV light. We found that the exposed and unexposed regions of the poly(HDMA‐co‐DNAM)s copolymer LB films had solubility differentiation in gold etchant, which is a mixed solution of I2/NH4I/C2H5OH/H2O. Therefore, we could obtain gold photopattern with the maximal resolution of the employed mask without any development process. Copyright © 2011 John Wiley & Sons, Ltd.
Mechanical and thermal properties of epoxidized soybean oil plasticized polybutylene succinate blends
Authors: Zhao Yongqing , Qu Jinping , Feng Yanhong , Wu Zhenghuan , Chen Fuquan , Tang Hailong
Published: April 2011

Epoxidized soybean oil (ESO) was blended as a novel plasticizer with polybutylene succinate (PBS) in a twin‐screw extruder. The effects of ESO on the mechanical and thermal properties of the PBS/ESO blends were investigated by means of tensile test, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and scanning electronic microscope. ESO improved elongation at break for PBS, which increased and then decreased with the increase in ESO. Elongation at break reached a maximum of 15 times than that for pure PBS when the ESO loading was 5 wt%. The tensile strength and modulus for the blends were lower than those for pure PBS. Compared with pure PBS, the blends exhibited lower glass transition temperature, crystallization temperature, and melting temperature. The storage modulus and tan δ peaks for the blends were lower compared with that for pure PBS. ESO had very limited compatibility with PBS, and phase separation was observed when more ESO was added. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and mechanical strength of a novel double network nanocomposite hydrogel with core‐shell structure
Authors: Fei Xiang , Lin Jiangli , Wang Jide , Lin Jiantao , Shi Xiaomei , Xu Shimei
Published: April 2011

A novel poly[(dimethylimino)(2‐hydroxy‐1,3‐propanedily)chloride]/Laponite/polyacrylic acid (PDMIHPC/Clay/PAA) hydrogel was synthesized by two‐step solution polymerization combining the strategies of both nanocomposite (NC) gels and double network (DN) gels. The chemical composition and core‐shell structure of the hydrogels were confirmed by Fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The mechanical strength was examined by varying the reaction temperature, PDMIHPC/Clay composite dose, N,N′‐methylenebisacrylamide (MBAM) dose and water content. When the reaction temperature was 35°C, PDMIHPC/Clay composite/AA is 1:10 and MBAM dose was 0.050 wt% (based on the weight of AA), the novel hydrogel achieved a best compressive strength of 100.05 KPa with a water content of 98.8%. Copyright © 2011 John Wiley & Sons, Ltd.
Study of electrochromic devices with nanocomposites polymethacrylate hydroxyethylene resin based electrolyte
Authors: Gonçalves A. , Costa C. , Pereira S. , Correia N. , Silva M. M. , Barbosa P. C. , Rodrigues L. C. , Henriques I. , Martins R. , Fortunato E.
Published: April 2011

This paper reports the application of a polymethacrylate hydroxyethylene resin based electrolyte in electrochromic (EC) devices. The electrolyte is characterized by electrochemical impedance spectroscopy, visible spectroscopy, TGA, DSC, and DRX and tested as an ionic conductor in an EC device with the following configuration: Substrate/IZO/WO3/Polymer Electrolyte/(CeO2)TiO2/IZO/Substrate. The electrolyte presents an ionic conductivity of 10−7 S/cm at room temperature and TGA analysis show that electrolyte is thermally degraded at 200°C. The EC device based on this polymethacrylate hydroxyethylene resin electrolyte system shows memory effect and exhibits an excellent optical density. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and mechanism of polyaniline nanotubes with rectangular cross section via in situ polymerization
Authors: Zhu Shibu , Chen Xiangnan , Gou Yu , Zhou Zuowan , Jiang Man , Lu Jun , Hui David
Published: April 2011

Polyaniline (PANI) nanotubes with rectangular cross section, which had 90–500 nm in outer diameter and 30–400 nm in inner diameter, were synthesized via a self‐assembly process in the presence of chiral acid (1S)‐(+)‐10‐camphorsulfonic (D‐CSA) and non‐chiral hydrochloric acid (HCl) coordinating with sodium dodecylbenzenesulfonate (SDBS), respectively. By using SEM, TEM, OM, FTIR, and WAXD, the as‐prepared PANI nanotubes with diversified morphologies were also characterized so as to investigate the formation mechanism of such tubular nanostructures with square cross sections. The results showed that the bilayer‐lamellar micelles formed by anilinium cations and CSA anions acted as the primary templates in the formation of the flat oligomer flakes, and the flakes finally united together to form rectangular nanotubes initiated by the reaction of the active centers on their edges. This study sheds light on the formation process of the PANI nanotubes with rectangular holes and outer contours and may be instructive to the controllable growth of certain nanostructures with unique morphologies. Copyright © 2011 John Wiley & Sons, Ltd.
Macro reversible addition–fragmentation chain transfer agent mixture as a means to enhance the electro‐optical performance of polymer‐dispersed liquid crystals
Authors: Du Xin , Yan Bin , Li Minke , Chen Shu , Yao Jiali , Wang Yinghan
Published: April 2011

Macro reversible addition–fragmentation chain transfer (RAFT) agents, i.e. RAFT polystyrene (RAFT‐PS) and RAFT poly(n‐butyl acrylate) (RAFT‐PBA), were mixed. Polymer‐dispersed liquid crystals (PDLCs) were prepared using the mixture together with methyl acrylate and liquid crystal E7. The electro‐optical properties of the PDLCs obtained were investigated. The results showed that the advantages of the electro‐optical properties of RAFT‐PS‐ and RAFT‐PBA‐dependent PDLCs could be combined in RAFT agent mixture‐dependent PDLCs. Copyright © 2011 Society of Chemical Industry
Recent research progress on the preparation and application of magnetic nanospheres
Authors: Tai Yulei , Wang Li , Yan Guangqing , Gao Jin‐min , Yu Haojie , Zhang Lei
Published: April 2011

Magnetic nanospheres have numerous applications in biomedicine, biotechnology and wastewater treatment, due to their high surface area, tunable sphere size and superparamagnetic properties. Magnetic nanoparticles can be designed and endowed with optical, electronic and fluorescent properties, allowing a wide range of functionality. Multifunctional magnetic particles with heterodimer structures allow various kinds of target molecules to be attached onto their specific parts via affinity or coordinate bonding, etc. The abilities of these nanodevices, including the encapsulation of target molecules in magnetic hybrid nanostructures and easy magnetic separation in the presence of external magnetic fields, show much promise for magnetic imaging, magnetic separation and drug delivery. Consequently, magnetic particles offer excellent potential future uses in disease diagnosis, hyperthermia, immunoassays, electrochemical biosensors, contaminated water treatment and optical detection. In this article, we review the preparation and application of inorganic and organic magnetic composite spheres in the fields of magnetic separation, drug delivery, hyperthermia, magnetic resonance imaging, and others. The size, specific surface area, structure, magnetic properties and surface functional groups of nanospheres have a great influence on their effectiveness in these applications. The encapsulation of target molecules in magnetic hybrid nanostructures and their easy separation using an external magnetic field show promise for the fabrication of novel nanodevices for many applications. Copyright © 2011 Society of Chemical Industry
Novel copoly(ether ether ketone)s with pendant phenyl groups: synthesis and characterization
Authors: Wu Ting , Liu Pengqing , Shi Meiwu , Lu Jun , Ye Guangdou , Xu Jianjun
Published: April 2011

In order to obtain poly(ether ether ketone)s having enhanced solubility and processability without extreme loss of other properties, a series of copoly(ether ether ketone)s (Co‐PEEKs) with pendant phenyl groups were synthesized from 1,1‐bi(4‐hydroxyphenyl)‐1‐phenylethane (ph‐BPA), hydroquinone and 4,4′‐difluorobenzophenone via aromatic nucleophilic substitution reaction. The structures and properties of the Co‐PEEKs were characterized using Fourier transform infrared and 1H NMR spectroscopies, differential scanning calorimetry, thermogravimetric analysis, wide‐angle X‐ray diffraction and solubility testing. These Co‐PEEKs have inherent viscosities in the range 0.14–1.09 dL g−1, and their number‐average and weight‐average molecular weights reach 72 659 and 163 400 g mol−1, respectively. The Co‐PEEK with the lowest content of ph‐BPA has a semi‐crystalline nature and is only soluble in 98% sulfuric acid. However, with an increase of ph‐BPA in the Co‐PEEKs, they become amorphous and readily soluble in a wide range of organic solvents and can afford tough films. These Co‐PEEKs have glass transition temperatures of 137–180 °C depending on the content of ph‐BPA. All the Co‐PEEKs have initial degradation temperatures above 480 °C in nitrogen atmosphere. Thus, these Co‐PEEKs with excellent thermal stability, good solubility and processability have potential for use in high‐performance films, coatings, hollow fiber membranes, etc. Copyright © 2011 Society of Chemical Industry
Influence of surface‐modified nanoclay on the self‐organized nanostructure of segmented polyurethane composites
Authors: Mondal Manas , Chattopadhyay Pijush K , Setua Dipak K , Das Narayan C , Chattopadhyay Santanu
Published: April 2011

The nanoscale morphology of segmented polyurethane (SPU) nanocomposites containing various proportions of organomodified montmorillonite (MMT) and Laponite (dual modified using ionic amine modification followed by silane modification) was studied. These nanocomposites were prepared by solution casting and characterized using small‐angle X‐ray scattering (SAXS), transmission electron microscopy (TEM), variable‐temperature X‐ray diffraction (VT‐XRD) and modulated differential scanning calorimetry (MDSC). TEM micrographs show uniform dispersion of MMT in SPU nanocomposites, and the dispersion is better than in Laponite‐based ones. Nanocrystalline morphology development in annealed samples of the nanocomposites was studied using VT‐XRD (140 to 25 °C at constant cooling rate), which confirms the formation of near‐triclinic unit cell geometry with different planes of reflection depending on temperature, type of clay and modification (aspect ratio, polarity). It is found that clay (MMT) having higher aspect ratios imposes greater restrictions against the formation of crystallographic planes of various inclinations. The overall crystallinity of SPU appears less affected in the presence of Laponite as compared to MMT. This is confirmed by the MDSC results showing variations and multiplicity of the glass transition temperature and entropies. Finally, SAXS studies related to interdomain repeat distances and interfacial roughness give an in‐depth understanding regarding the effect of nanoclay on annealing, crystallinity and reinforcement of polymer microstructures. Such reinforcement effect is maximized in the case of dual‐modified Laponite‐based SPU. Copyright © 2011 Society of Chemical Industry
Fabrication of antibacterial silicone composite by an antibacterial agent deposition, solution casting and crosslinking technique
Authors: Tang Chak Yin , Chen Da‐zhu , Chan Kathy Yuen Yee , Chu Kit Man , Ng Pak Cheung , Yue Tai Man
Published: April 2011

The key problems faced in developing indwelling catheters are how to incorporate antibacterial agents into the substrate and how to improve the antibacterial effectiveness. In this study, an antibacterial composite coating layer is inversely in situ formed on the silicone substrate by a novel technique involving deposition of an antibacterial agent, solution casting and crosslinking of a silicone resin. The antibacterial particles were strongly bonded to the matrix silicone and evenly dispersed on the coating surface. Moreover, energy‐dispersive X‐ray analysis revealed the gradient distribution of the antibacterial agent, perpendicular to the composite surface. The co‐instantaneous crosslinking within the coating layer and polymer substrate as well as the graded structure formed lead to good adhesion between the two parts. The silicone composite shows a highly efficient antibacterial activity with no cytotoxicity to HL‐60 cells. Compared with the commonly used methods of incorporating antibacterial agents into the silicone substrate, such as multiple dip‐coating, surface grafting or simple blending, the proposed process is easily operated and is promising for forming a percutaneous or subcutaneous device with the capacity for efficient sterilization in an economical way. Copyright © 2011 Society of Chemical Industry
Low band gap copolymers consisting of porphyrins, thiophenes, and 2,1,3‐benzothiadiazole moieties for bulk heterojunction solar cells
Authors: Zhou Weiping , Shen Ping , Zhao Bin , Jiang Peng , Deng Lijun , Tan Songting
Published: April 2011

Two novel low band gap conjugated copolymers containing porphyrins, thiophenes, and 2,1,3‐benzothiadiazole (BTZ) moieties were synthesized and applied in bulk heterojunction solar cells. The thermal, optical, electrochemical, and photovoltaic properties of the two copolymers were examined to investigate the effect of the introduction of BTZ moiety in the backbone of the porphyrin polymers. The copolymers exhibited good thermal stability and film‐forming ability. The absorption spectra indicated that the BTZ moiety has significant influence on the UV–visible region spectra of the copolymers: with increasing the molar amount of BTZ moieties in conjugated main chain, the absorption in the range of 450–700 nm is largely broadened and red‐shifted compared to the similar polymers without BTZ moiety, and the optical band gaps of copolymers were narrowed to ∼1.50 eV. The photoluminescence spectra showed that there is effective charge transfer in the whole conjugated main chain. Cyclic voltammetry displayed that the band gaps were reduced effectively by the introduction of the BTZ moieties. The bulk heterojunction solar cells were fabricated based on the blend of the copolymers and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) in a 1:2 weight ratio. The maximum power conversion efficiency of 0.91% was obtained by using P2 as the electron donor under the illumination of AM 1.5, 100 mW/cm2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Plasma Polymerized Silylated Ciprofloxacin as an Antibiotic Coating
Authors: Braceras Inigo , Azpiroz Patxi , Briz Nerea , Fratila Raluca M. , Oyarbide Joseba , Ipiñazar Enrique , Álvarez Noelia , Atorrasagasti Garbiñe , Aizpurua Jesus M.
Published: April 2011

Locally applied antibiotics under temporally controlled release present many advantages over systemic clinical treatments, e.g. efficiency and side effects. This can be achieved by a coating on top of the medical device, in which the antibiotic is stored. This study presents the use of plasma polymerization to produce such a coating using N,O‐bis‐tert‐butyldimethylsilylated ciprofloxacin (silylciprofloxacin) as a precursor. Once exposed to physiological media, the outer layers of the coating release the antibiotic by a hydrolysis reaction. Thus, the plasma process parameters can control the speed of liberation through the coating polymerization. Besides, this study shows that the release products present antibiotic activity against a number of bacteria: E. coli, P. aeruginosa, and S. aureus.

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MALDI‐TOF MS profiling as the first‐tier screen for sickle cell disease in neonates: Matching throughput to objectives
Authors: Hachani Johan , Duban‐Deweer Sophie , Pottiez Gwënaël , Renom Gilles , Flahaut Christophe , Périni Jean‐Marc
Published: April 2011

Purpose: Universal newborn screening for sickle cell diseases (SCDs) is not currently performed in many countries concerned by this public health problem. Owing to the technical and financial limitations of standard profiling methods (IEF coupled to subsequent HPLC), ethnically targeted neonatal screening is often preferred. Here, we demonstrate that MALDI‐MS‐based SCD newborn screening could be considered as a potential method for a strategy to universal screening because of its high throughput, cost‐effectiveness, sensitivity and ability to automatically discriminate sickle haemoglobin.

Experimental design: We carried out a retrospective study of dried blood spots from 844 Guthrie cards. Four determinations of 1000 mass spectra were performed from each tested dried blood spot.

Results: The MALDI‐MS‐based screening was highly correlated with the reference method. Only 2.3% of the samples presented a poor spectral quality.

Conclusions and clinical relevance: Given that the overall acquisition, data reprocessing and software‐assisted classification (ClinProTools™) time for processing four mass determinations (corresponding to one sample) was around 1 min, 1000 samples can be analysed per day. Rather than seeking to detect as many different haemoglobinopathies as possible, it would become possible to use MALDI‐TOF‐MS to screen (at a constant cost) as many samples as possible for sickle cell disease.
Y‐system for scattering amplitudes
Authors: Alday L.F.
Published: April 2011

We review recent progress on computing scattering amplitudes of planar 𝒩 = 4 super Yang‐Mills at strong coupling by using the AdS/CFT duality. The problem boils down to the computation of certain minimal areas on AdS. We show how to use the integrability of the classical equations of motion in order to efficiently compute such minimal areas.
Cosmological insights into fundamental physics
Authors: Jimenez R.
Published: April 2011

Significant progress has been made recently in the field of observational cosmology. This has allowed for an unprecedented picture of the early universe and its evolution. In this review I will present a (biased) view of how one can use these observational results to constraint fundamental physics.
Holographic phase transitions and universality
Authors: Benincasa P.
Published: April 2011

In this talk we analyze the phase diagram in the plane temperature versus baryonic chemical potential for gauge theories with flavors in the quenched approximation, using holography. In the case of massive flavors, we observe the existence of two universality classes, which are identified by the order of the meson melting transition in the interior of the phase plane. Specifically, gauge theories whose flavor degrees of freedom propagate in the whole bulk appear to have a third order phase transition, while the phase transition is of second order if they propagate on a codimension‐1 defect.
Benchmark study on glyphosate‐resistant cropping systems in the United States. Part 4: Weed management practices and effects on weed populations and soil seedbanks
Authors: Wilson Robert G , Young Bryan G , Matthews Joseph L , Weller Stephen C , Johnson William G , Jordan David L , Owen Micheal DK , Dixon Philip M , Shaw David R
Published: April 2011

BACKGROUND: Weed management in glyphosate‐resistant (GR) maize, cotton and soybean in the United States relies almost exclusively on glyphosate, which raises criticism for facilitating shifts in weed populations. In 2006, the benchmark study, a field‐scale investigation, was initiated in three different GR cropping systems to characterize academic recommendations for weed management and to determine the level to which these recommendations would reduce weed population shifts.

RESULTS: A majority of growers used glyphosate as the only herbicide for weed management, as opposed to 98% of the academic recommendations implementing at least two herbicide active ingredients and modes of action. The additional herbicides were applied with glyphosate and as soil residual treatments. The greater herbicide diversity with academic recommendations reduced weed population densities before and after post‐emergence herbicide applications in 2006 and 2007, particularly in continuous GR crops.

CONCLUSION: Diversifying herbicides reduces weed population densities and lowers the risk of weed population shifts and the associated potential for the evolution of glyphosate‐resistant weeds in continuous GR crops. Altered weed management practices (e.g. herbicides or tillage) enabled by rotating crops, whether GR or non‐GR, improves weed management and thus minimizes the effectiveness of only using chemical tactics to mitigate weed population shifts. Copyright © 2011 Society of Chemical Industry
Exploring the Conditions for a Mortality Crisis: Bringing Context Back into the Debate
Authors: Billingsley Sunnee
Published: April 2011

This study engages with the debate over the mortality crises in the former Soviet Union and Central and Eastern Europe by (i) considering at length and as complementary to each other the two most prominent explanations for the post‐communist mortality crisis, stress and alcohol consumption and by (ii) emphasising the importance of context by exploiting systematic similarities and differences across the region. Differential mortality trajectories reveal three country groups that cluster both spatially and in terms of economic transition experiences. The first group includes countries in the farthest west in which mortality rates increased minimally after the transition began. The second group experienced a severe increase in mortality rates in the early 1990s but recovered previous levels within a few years. These countries are located peripherally to Russia and its nearest neighbours. The final group consists of countries that experienced two mortality increases or in which mortality levels had not recovered to pre‐transition levels well into the 21st century. Cross‐sectional time‐series analyses of age‐specific and cause‐specific death rates for men and women reveal that the clustering of these countries and their mortality trajectories can be partially explained by the economic context, which is argued to be linked to stress and alcohol consumption. Above and beyond many basic differences in the country groups that are held constant – including geographically and historically shared cultural, lifestyle, and social characteristics – poor economic conditions account for a remarkably consistent share of excess age‐specific and cause‐specific deaths. Copyright © 2011 John Wiley & Sons, Ltd.
It is not Just the Economy: Declining Migration and the Rise of Secular Rootedness
Authors: Cooke Thomas J.
Published: April 2011

Americans have always been viewed, both by themselves and by others, as a migrant society. However, migration rates have reached record lows: only 1.6% of Americans moved from one state to another in 2009, and only 3.7% moved from one county to another. This research conducts a decomposition of the change in migration rates between 1999 and 2009 using data from the Current Population Survey. The analysis concludes that about 63% of the decline in migration rates between 1999 and 2009 can be attributed to the direct effects of the economic crisis that began in 2007, and another 17% of the decline can be attributed to demographic changes (e.g. the aging of the population) but that the remaining 20% of the decrease in migration is due to a decline in migration behaviour, or increased rootedness, that applies to all demographic categories. The discussion focuses on the implications of the universal, or secular, rise in rootedness for migration studies. Copyright © 2011 John Wiley & Sons, Ltd.
A cross‐layer game for energy‐efficient jamming detection in ad hoc networks
Authors: Thamilarasu G. , Sridhar R.
Published: April 2011

The objective of jamming attacks in a network is to deny service to the communicating nodes, thus reducing network throughput and availability. In this paper, we propose a game theoretic framework for detecting jamming attacks in wireless ad hoc networks. We formulate jamming as a two‐player, non‐cooperative game to analyze the interaction between the attacker and the monitoring nodes in the network. We propose hybrid detection strategies at the monitor node by using cross‐layer features for attack detection. We solve the game by computing the mixed‐strategy Nash equilibrium and derive the optimal attack and detection strategies. Numerical results show that game theoretic analysis can be used to determine the optimal steady‐state monitoring strategies to provide higher detection accuracy, while balancing the monitoring energy costs. Copyright © 2011 John Wiley & Sons, Ltd.
Stochastic curtailment of health questionnaires: A method to reduce respondent burden
Authors: Finkelman Matthew D. , He Yulei , Kim Wonsuk , Lai Albert M.
Published: April 2011

Stochastic curtailment is a sequential method to terminate a study when continuing to the end would be unlikely to change the outcome. This method has been researched most commonly in the context of clinical trials. The current paper explores its use in a different setting: the administration of a health questionnaire to patients via computer. A classification procedure augmenting logistic regression with stochastic curtailment is introduced to avoid burdening the patients with unnecessary questions. In a real‐data simulation using responses from the Medicare Health Outcomes Survey, the new procedure substantially reduced the average number of questions administered with a minimal loss of classification accuracy. Copyright © 2011 John Wiley & Sons, Ltd.
A simulation study of predictive ability measures in a survival model I: Explained variation measures
Authors: Choodari‐Oskooei Babak , Royston Patrick , Parmar Mahesh K. B.
Published: April 2011

Measures of predictive ability play an important role in quantifying the clinical significance of prognostic factors. Several measures have been proposed to evaluate the predictive ability of survival models in the last two decades, but no single measure is consistently used. The proposed measures can be classified into the following categories: explained variation, explained randomness, and predictive accuracy. The three categories are conceptually different and are based on different principles. Several new measures have been proposed since Schemper and Stare's study in 1996 on some of the existing measures. This paper is the first of two papers that study the proposed measures systematically by applying a set of criteria that a measure of predictive ability should possess in the context of survival analysis. The present paper focuses on the explained variation category, and part II studies the proposed measures in the other categories. Simulation studies are used to examine the performance of five explained variation measures with respect to these criteria, discussing their strengths and shortcomings. Our simulation studies show that the measures proposed by Kent and O'Quigley, R, and Royston and Sauerbrei, R, appear to be the best overall at quantifying predictive ability. However, it should be noted that neither measure is perfect; R is sensitive to outliers and R to (marked) non‐normality of the distribution of the prognostic index. The results show that the other measures perform poorly, primarily because they are adversely affected by censoring. Copyright © 2011 John Wiley & Sons, Ltd.
Assessing noninferiority in a three‐arm trial using the Bayesian approach
Authors: Ghosh Pulak , Nathoo, Farouk , Gönen Mithat , Tiwari Ram C.
Published: April 2011

Non‐inferiority trials, which aim to demonstrate that a test product is not worse than a competitor by more than a pre‐specified small amount, are of great importance to the pharmaceutical community. As a result, methodology for designing and analyzing such trials is required, and developing new methods for such analysis is an important area of statistical research. The three‐arm trial consists of a placebo, a reference and an experimental treatment, and simultaneously tests the superiority of the reference over the placebo along with comparing this reference to an experimental treatment. In this paper, we consider the analysis of noninferiority trials using Bayesian methods which incorporate both parametric as well as semi‐parametric models. The resulting testing approach is both flexible and robust. The benefit of the proposed Bayesian methods is assessed via simulation, based on a study examining home‐based blood pressure interventions. Copyright © 2011 John Wiley & Sons, Ltd.
Estimating cost‐offsets of new medications: Use of new antipsychotics and mental health costs for schizophrenia
Authors: O'Malley A. James , Frank R. G. , Normand S.‐L. T.
Published: April 2011

Estimation of the effect of one treatment compared to another in the absence of randomization is a common problem in biostatistics. An increasingly popular approach involves instrumental variables—variables that are predictive of who received a treatment yet not directly predictive of the outcome. When treatment is binary, many estimators have been proposed: method‐of‐moments estimators using a two‐stage least‐squares procedure, generalized‐method‐of‐moments estimators using two‐stage predictor substitution or two‐stage residual inclusion procedures, and likelihood‐based latent variable approaches. The critical assumptions to the consistency of two‐stage procedures and of the likelihood‐based procedures differ. Because neither set of assumptions can be completely tested from the observed data alone, comparing the results from the different approaches is an important sensitivity analysis. We provide a general statistical framework for estimation of the casual effect of a binary treatment on a continuous outcome using simultaneous equations to specify models. A comparison of health care costs for adults with schizophrenia treated with newer atypical antipsychotics and those treated with conventional antipsychotic medications illustrates our methods. Surprisingly large differences in the results among the methods are investigated using a simulation study. Several new findings concerning the performance in terms of precision and robustness of each approach in different situations are obtained. We illustrate that in general supplemental information is needed to determine which analysis, if any, is trustworthy and reaffirm that comparing results from different approaches is a valuable sensitivity analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Intravital Imaging of Human Prostate Cancer Using Viral Nanoparticles Targeted to Gastrin‐Releasing Peptide Receptors
Authors: Steinmetz Nicole F. , Ablack Amber L. , Hickey Jennifer L. , Ablack Jailal , Manocha Bhavik , Mymryk Joe S. , Luyt Leonard G. , Lewis John D.
Published: April 2011

Multivalent nanoparticles have several key advantages in terms of solubility, binding avidity, and uptake, making them particularly well suited to molecular imaging applications. Herein is reported the stepwise synthesis and characterization of NIR viral nanoparticles targeted to gastrin‐releasing peptide receptors that are over‐expressed in human prostate cancers. The pan‐bombesin analogue, [β‐Ala11, Phe13, Nle14]bombesin‐(7–14), is conjugated to cowpea mosaic virus particles functionalized with an NIR dye (Alexa Fluor 647) and polyethylene glycol (PEG) using the copper(I)‐catalyzed azide‐alkyne cycloaddition reaction. Targeting and uptake in human PC‐3 prostate cells is demonstrated in vitro. Tumor homing is observed using human prostate tumor xenografts on the chicken chorioallantoic membrane model using intravital imaging. Further development of this viral nanoparticle platform may open the door to potential clinical noninvasive molecular imaging strategies.
Patterning of Conjugated Polymers for Organic Optoelectronic Devices
Authors: Xu Youyong , Zhang Fan , Feng Xinliang
Published: April 2011

Conjugated polymers have been attracting more and more attention because they possess various novel electrical, magnetical, and optical properties, which render them useful in modern organic optoelectronic devices. Due to their organic nature, conjugated polymers are light‐weight and can be fabricated into flexible appliances. Significant research efforts have been devoted to developing new organic materials to make them competitive with their conventional inorganic counterparts. It is foreseeable that when large‐scale industrial manufacture of the devices made from organic conjugated polymers is feasible, they would be much cheaper and have more functions. On one hand, in order to improve the performance of organic optoelectronic devices, it is essential to tune their surface morphologies by techniques such as patterning. On the other hand, patterning is the routine requirement for device processing. In this review, the recent progress in the patterning of conjugated polymers for high‐performance optoelectronic devices is summarized. Patterning based on the bottom‐up and top‐down methods are introduced. Emerging new patterning strategies and future trends for conventional patterning techniques are discussed.
Agile software product line engineering: enabling factors
Authors: Hanssen Geir K.
Published: April 2011

This paper reports on a study of a software product line organization that has adopted agile software development to address process rigidity and slowing performance. Experience has showed that despite some impediments, this has become a valuable change to both the organization and its development process. The aim of this study is to identify and understand enabling factors of a combined process, and to understand their subsequent effects. Qualitative data are summarized and analyzed, giving insight into the actions taken, their effects that have emerged over time, and the enabling and contextual factors. The study concludes that a combined process is feasible, that the simplified approach makes the organization more flexible and thus capable of serving a volatile market with fast‐changing technologies. This has also enabled the organization to collaborate better with external actors. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptive random testing through test profiles
Authors: Liu Huai , Xie Xiaodong , Yang Jing , Lu Yansheng , Chen Tsong Yueh
Published: April 2011

Random testing (RT), which simply selects test cases at random from the whole input domain, has been widely applied to test software and assess the software reliability. However, it is controversial whether RT is an effective method to detect software failures. Adaptive random testing (ART) is an enhancement of RT in terms of failure‐detection effectiveness. Its basic intuition is to evenly spread random test cases all over the input domain. There are various notions to achieve the goal of even spread, and each notion can be implemented by different algorithms. For example, ‘by exclusion’ and ‘by partitioning’ are two different notions to evenly spread test cases. Restricted random testing (RRT) is a typical algorithm for the notion of ‘by exclusion’, whereas the notion of ‘by partitioning’ can be implemented by either the technique of bisection (ART‐B) or the technique of random partitioning (ART‐RP). In this paper, we propose a generic approach that can be used to implement different notions. In the new approach, test cases are simply selected based on test profiles that are in turn designed according to certain notions. In this study, we design several test profiles for the notions of ‘by exclusion’ and ‘by partitioning’, and then use these profiles to illustrate our new approach. Our experimental results show that compared with the original RRT, ART‐B, and ART‐RP algorithms, our new approach normally brings at least a higher failure‐detection capability or a lower computational overhead. Copyright © 2011 John Wiley & Sons, Ltd.
Antenatal ultrasound prediction of pulmonary hypoplasia in congenital diaphragmatic hernia: correlation with pathology
Authors: Jani J. C. , Cordier A.‐G. , Martinovic J. , Peralta C. F. , Senat M.‐V. , Segers V. , Benachi A.
Published: April 2011

Objective

To examine the relationship between observed to expected (o/e) lung to head circumference ratio (LHR) and lung‐to‐body weight ratio (LBWR) in fetuses with congenital diaphragmatic hernia (CDH).

Methods

All consecutive fetuses with CDH and termination of pregnancy for which a postmortem examination was available, examined at three institutions between 2000 and 2010, were included in the study. Contralateral fetal lung area was measured by two‐dimensional ultrasonography using the longest axis method and the o/e‐LHR was calculated based on the appropriate normal mean for gestational age (GA). Regression analysis was used to determine the significance of association between the LBWR and the o/e‐LHR for left and right‐sided cases, and subsequently the predicted LBWR in left‐sided CDH was calculated using the regression equation. Regression analysis was used to investigate the effect on the proportional difference between the predicted and observed LBWR of GA at o/e‐LHR, time gap between o/e‐LHR and LBWR measurement, proportional weight of the ipsilateral compared with total lung weight, presence of associated anomalies and intrathoracic herniation of the liver.

Results

There were 23 fetuses with left‐sided and seven fetuses with right‐sided CDH. In left‐sided CDH, the LBWR and the o/e‐LHR correlated significantly, following the linear equation: LBWR = 0.0043 + (0.0134 × o/e‐LHR) (r = 0.52, P = 0.012), but this was not the case for right‐sided CDH, for which LBWR followed the equation: LBWR = 0.0107 − (0.0014 × o/e‐LHR) (r = 0.08, P = 0.862), where o/e‐LHR is expressed as percentage. Regression analysis showed that the proportional difference between predicted and observed LBWR in left‐sided CDH was significantly and independently associated with GA at o/e‐LHR measurement and proportional weight of ipsilateral vs. total lung weight.

Conclusion

In left‐sided CDH, o/e‐LHR correlates well with LBWR irrespective of the length of time between o/e‐LHR and LBWR measurement, presence of associated anomalies and intrathoracic herniation of the liver. Inconsistencies between the two measurements are mainly attributable to the contribution of the ipsilateral lung to the total lung weight. In right‐sided CDH, o/e‐LHR does not correlate with LBWR. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Gestational sac fluid volume measurements in virtual reality
Authors: Rousian M. , Koning A. H. J. , Hop W. C. , van der Spek P. J. , Exalto N. , Steegers E. A. P.
Published: April 2011

Objectives

To evaluate a virtual reality (VR) application for gestational sac fluid volume (GSFV) measurements in first‐trimester pregnancies and to study the correlation between different embryonic growth parameters.

Methods

This was a prospective cohort study analyzing 180 three‐dimensional (3D) ultrasound scans of 42 healthy women, performed between 5 + 5 and 12 + 6 weeks' gestational age (GA). The 3D datasets were transferred to the I‐Space immersive VR system. The V‐Scope application was used to create a ‘hologram’ of the ultrasound image, allowing depth perception and interaction with the rendered objects. Volumes were measured semi‐automatically using a segmentation algorithm. In addition to the GSFV, the total gestational sac volume (GSV) and its diameter (GSD) were measured. The GSV was also calculated using the ellipsoid formula. Previously obtained measurements of embryonic volume and crown–rump length (CRL) were included in the study. The outcomes were analyzed using repeated‐measures analysis of variance.

Results

The GSFV was measured in 78 scans, and varied from 434 to 81 491 mm3. A positive correlation between GSFV and GA, CRL and GSD was found. Comparison of the GSD formula constructed in our study in relation to GA with a formula that is commonly used clinically showed an increasing difference with increasing GA either side of 8 + 5 weeks. The GSFV/embryonic volume ratio showed a decrease with GA. The GSV calculated using the ellipsoid formula was on average 19.8% larger compared with the GSV measured in VR.

Conclusion

New charts for first‐trimester GSFV were constructed using VR. These growth charts could be promising tools for studying normal and abnormal embryonic development. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Synthesis, Crystal and Electronic Structure of [K[18]crown‐6)]2[Sn2Bi2]
Authors: Lips Felicitas , Raupach Marc , Massa Werner , Dehnen Stefanie
Published: April 2011

Extraction of an alloy of the nominal composition “KSnBi” by an [18]crown‐6 melt, and subsequent by 1,2‐diaminoethane (en) resulted in the formation of a new ternary Zintl salt [K([18]crown‐6)]2[Sn2Bi2] (1) comprising the known binary anion [Sn2Bi2]2–. Herein we report synthesis and structure of 1, along with a density functional (DFT) study of the anion. The crystal structure of 1 was solved and refined in the cubic space group F23 (no. 196). Unit cell dimensions at 100 K: a = 20.8776(15) Å, V = 9100.0(11) Å3 [R(int) = 0.0467], final R values R1 = 0.0521, [I > 2σ(I)], wR2 = 0.0915 (all data).
NaSc3[HPO3]2[HPO2(OH)]6: Synthesis, Crystal Structure, and Thermal Decomposition
Authors: Chen Shuang , Prots Yurii , Kniep Rüdiger , Hoffmann Stefan
Published: April 2011

NaSc3[HPO3]2[HPO2(OH)]6 was prepared by use of a phosphorus acid flux route. The crystal structure was determined from single‐crystal X‐ray diffraction data: triclinic, space group P$\bar{1}$ (No. 2), a = 7.4507(11) Å, b = 9.6253(17) Å, c = 9.6141(16) Å, α = 115.798(4)°, β = 101.395(4)°, γ = 101.136(3)°, V = 577.29(16) Å3 and Z = 1. The crystal structure of NaSc3[HPO3]2[HPO2(OH)]6 contains two kinds of phosphate(III) groups: HPO32– and HPO2(OH)–. Phosphate(III)‐tetrahedra, NaO6 and ScO6 octahedra together form a (3,6)‐connected net. During heating hydrogen and water are released and Sc[PO3]3 is formed as the main crystalline decomposition product.