bluuebunny/crossref_metadata_2025 huggingface dataset:
The ADAS‐cog and clinically meaningful change in the VISTA clinical trial of galantamine for Alzheimer's disease
Authors: Rockwood Kenneth , Fay Sherri , Gorman Mary
Published: June 2009

Background

A minimum 4‐point change at 6 months on the Alzheimer's disease assessment scale‐cognitive subscale (ADAS‐cog) is deemed clinically important, but this cut‐point has been little studied in relation to clinical meaningfulness. In an investigator‐initiated, clinical trial of galantamine, we investigated the extent to which a 4‐point change classifies goal attainment by individual patients.

Methods

Secondary analysis of the video imaging synthesis of treating Alzheimer's disease (VISTA) study: a 4‐month, multi‐centre, parallel‐group, double‐blind, placebo‐controlled, trial of galantamine in 130 mild‐moderate Alzheimer's disease patients (4‐month open‐label follow‐up). ADAS‐cog responses at 6 months were compared with outcomes on three clinical measures: clinician's interview based impression of change‐plus caregiver input (CIBIC+), patient/carer‐goal attainment scaling (PGAS) and clinician‐GAS (CGAS).

Results

Thirty‐seven of 99 patients improved by ≥ 4 points on the ADAS‐cog at 6 months, and 16/99 showed ≥ 4‐point worsening. ADAS‐cog change scores correlated notionally to modestly with changes on the CGAS (r = −0.31), the PGAS (r = −0.29) and the CIBIC+ (r = 0.31). As a group, patients with ADAS‐cog improvement were significantly more likely to improve on the clinical measures; those who worsened showed non‐significant clinical decline. Individually, about half were misclassified in relation to each clinical measure; often when the ADAS‐Cog detected ‘no change’, clinically meaningful effects could be detected. Even so, no ADAS‐Cog cut‐point optimally classified patients' clinical responses.

Conclusion

A 4‐point ADAS‐cog change at 6 months is clinically meaningful for groups. Substantial individual misclassification between the ADAS‐cog and clinical measures suggests no inherent meaning to a 4‐point ADAS‐cog change for a given patient. Copyright © 2009 John Wiley & Sons, Ltd.
Serum levels of brain‐derived neurotrophic factor in comorbidity of depression and alcohol dependence
Authors: Umene‐Nakano Wakako , Yoshimura Reiji , Ikenouchi‐Sugita Atsuko , Hori Hikaru , Hayashi Kenji , Ueda Nobuhisa , Nakamura Jun
Published: June 2009

Alcohol dependence is often comorbid with depression. The purpose of the present study was to compare serum brain‐derived neurotrophic factor (BDNF) levels between depressive patients with and without alcohol dependence. Our subjects were 16 inpatients (M/F: 13/3, age: 48 ± 8 years) at our university hospital who met the DSM‐IV‐TR criteria for both major depressive disorder and alcohol dependence and whose Hamilton Rating Scale for Depression (HAM‐D) scores were at least 15. Twenty sex‐ and age‐matched depressive patients and 20 healthy subjects were also examined. Serum BDNF levels in the depressive patients with (9.0 ± 4.3 ng/ml) and without (9.8 ± 5.2 ng/ml) alcohol dependence were significantly lower than those in the healthy subjects (21.1 ± 7.0 ng/ml); however, no significant difference was found in the serum BDNF levels of depressive patients with and without alcohol dependence. Eight of the 16 (50%) depressive patients suffering from both depression and alcohol dependence responded to 8 weeks of treatment with antidepressant drugs which significantly increased their serum BDNF levels. These results suggest that the serum BDNF level is a useful biological marker for depression in patients with alcohol dependence. Copyright © 2009 John Wiley & Sons, Ltd.
Sleep arrangements and night waking at 6 and 12 months in relation to infants' stress‐induced cortisol responses
Authors: Lucas‐Thompson Rachel , Goldberg Wendy A. , Germo Gary R. , Keller Meret A. , Davis Elysia P. , Sandman Curt A.
Published: June 2009

The objective of this short‐term longitudinal study was to examine the concurrent and prospective associations of infants' sleep arrangements and night waking with cortisol responses to an inoculation at 6 and 12 months, controlling for several key covariates. To our knowledge, this was the first study to concurrently and prospectively link proximity in sleep arrangements and night waking to physiological stress reactivity. A sample of 92 mother–infant dyads participated in the study when the infants were 6 and 12 months of age, although sample sizes were reduced for some analyses. Both proximal cosleeping arrangements and more frequent night wakings' were associated concurrently with an increased cortisol response to inoculations at both ages. Night waking at 6 months also was associated with a slightly increased cortisol response to inoculation at 12 months. Results aimed at exploring the direction of influence suggested that cosleeping and night waking may influence infant stress physiology rather than the reverse. Adaptive and maladaptive implications of infants' nocturnal experiences and greater stress‐induced cortisol responses are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Cholesterol and Kir channels
Authors: Levitan Irena
Published: June 2009

To date, most of the major types of Kir channels, Kir2s, Kir3s, Kir4s, and Kir6s, have been found to partition into cholesterol‐rich membrane domains and/or to be regulated by changes in the level of membrane cholesterol. Surprisingly, however, in spite of the structural similarities between different Kirs, effects of cholesterol on different types of Kir channels vary from cholesterol‐induced decrease in the current density (Kir2 channels) to the loss of channel activity by cholesterol depletion (Kir4 channels) and loss of channel coupling by different mediators (Kir3 and Kir6 channels). Recently, we have gained initial insights into the mechanisms responsible for cholesterol‐induced suppression Kir2 channels, but mechanisms underlying cholesterol sensitivity of other Kir channels are mostly unknown. The goal of this review is to present a summary of the current knowledge of the distinct effects of cholesterol on different types of Kir channelsin vitroandin vivo. © 2009 IUBMB IUBMB Life 61(8): 781–790, 2009
The HCV ARFP/F/core+1 protein: Production and functional analysis of an unconventional viral product
Authors: Vassilaki Niki , Mavromara Penelope
Published: June 2009

Hepatitis C virus (HCV) is an enveloped positive‐strand RNA virus of the Flaviviridae family. It has a genome of about 9,600 nucleotides encoding a large polyprotein (about 3,000 amino acids) that is processed by cellular and viral proteases into at least 10 structural and nonstructural viral proteins. A novel HCV protein has also been identified by our laboratory and others. This protein—known as ARFP (alternative reading frame protein), F (for frameshift) or core+1 (to indicate the position) protein ‐ is synthesized by an open reading frame overlapping the core gene at nucleotide +1 (core+1 ORF). However, almost 10 years after its discovery, we still know little of the biological role of the ARFP/F/core+1 protein. Abolishing core+1 protein production has no affect on HCV replication in cell culture or uPA‐SCID mice, suggesting that core+1 protein is probably not important for the HCV reproductive cycle. However, the detection of specific anti‐core+1 antibodies and T‐cell responses in HCV‐infected patients, as reported by many independent laboratories, provides strong evidence that this protein is produced in vivo. Furthermore, analyses of the HCV sequences isolated from patients with hepatocellular carcinoma and in vitro studies have provided strong preliminary evidence to suggest that core+1 protein plays a role in advanced liver disease and liver cancer. The available in vitro data also suggest that certain core function proteins may depend on production of the core+1 protein. We describe here the discovery of the various forms of the core+1 protein and what is currently known about the mechanisms of their production and their biochemical and functional properties. We also provide a detailed summary of the results of patient‐based research. © 2009 IUBMB IUBMB Life, 61(7): 739–752, 2009
Verprolin: A cool set of actin‐binding sites and some very HOT prolines
Authors: Munn Alan L. , Thanabalu Thirumaran
Published: June 2009

Model for verprolin function. See Verprolin: A Cool Set of Actin‐binding Sites and Some Very HOT Prolines by Munn and Thanabalu, pp. 707–712.
Measuring state dependence in individual poverty histories when there is feedback to employment status and household composition
Authors: Biewen Martin
Published: June 2009

This paper argues that the assumption of strict exogeneity, which is usually invoked in estimating models of state dependence with unobserved heterogeneity, is violated in the poverty context as important variables determining contemporaneous poverty status, in particular employment status and household composition, are likely to be influenced by past poverty outcomes. Therefore, a model of state dependence is developed that explicitly allows for possible feedback effects from past poverty to future employment and household composition outcomes. Empirical results based on data from the German Socio‐Economic Panel (GSOEP) suggest that there are indeed such feedback effects and that failure to take them into account may lead to biased estimates of the state dependence effect. Copyright © 2009 John Wiley & Sons, Ltd.
Estimating class‐specific parametric models under class uncertainty: local polynomial regression clustering in an hedonic analysis of wine markets
Authors: Costanigro Marco , Mittelhammer Ron C. , McCluskey Jill J.
Published: June 2009

We introduce a method for estimating multiple class regression models when class membership is uncertain. The procedure—local polynomial regression clustering—first estimates a nonparametric model via local polynomial regression, and then identifies the underlying classes by aggregating sample observations into data clusters with similar estimates of the (local) functional relationships between dependent and independent variables. Finally, parametric functions specific to each class are estimated. The technique is applied to the estimation of a multiple‐class hedonic model for wine, resulting in the identification of four distinct wine classes based on differences in implicit prices of the attributes. Copyright © 2009 John Wiley & Sons, Ltd.
Witness confidence and accuracy: is a positive relationship maintained for recall under interview conditions?
Authors: Kebbell Mark R.
Published: June 2009

A large positive correlation between eyewitness recall confidence and accuracy (C‐A) is found in research when item difficulty is varied to include easy questions. However, these results are based on questionnaire responses. In real interviews, the social nature of the interview may influence C‐A relationships, and it is the interviewer's perception of the accuracy of a witness that counts. This study was conducted to investigate the influence of these factors for recall of a video. Three conditions were used; the same questions were used in each. Participants in condition 1 (self‐rate questionnaire condition, n = 20) were given a questionnaire that required them to answer questions and rate confidence on a scale. Pairs of participants in condition 2 (self‐rate interview condition, n = 40) were given the role of eyewitness or interviewer. Eyewitnesses were asked questions by an interviewer and responded orally with answers and confidence judgements on a Likert scale. Participants in condition three (interviewer‐rate interview condition, n = 40) were tested in the same way as condition two but provided confidence judgements in their own words. Interviewers independently rated each confidence judgement on the Likert scale. The experiment showed high C‐A relationships, particularly for ‘absolutely sure’ responses. The main effect of the social interview condition was to increase confidence in correct answers but not in incorrect answers. However, the advantage of this effect was tempered by the fact that, although observers can differentiate between confident and less confident answers, less extreme confidence judgements were ascribed. Copyright © 2009 John Wiley & Sons, Ltd.
CARS microscopy of lipid stores in yeast: the impact of nutritional state and genetic background
Authors: Brackmann Christian , Norbeck Joakim , Åkeson Madeleine , Bosch Daniel , Larsson Christer , Gustafsson Lena , Enejder Annika
Published: June 2009

We have developed a protocol for sub‐micrometer resolved and chemically specific imaging of lipid storage in vivo employing coherent anti‐Stokes Raman scattering (CARS) microscopy of one of the most important model organisms Saccharomyces cerevisiae—the yeast cell. By probing the carbon–hydrogen vibration using the nonlinear process of CARS, lipid droplets in the yeast cells clearly appear, as confirmed by comparative studies on relevant labeled organelles using two‐photon fluorescence microscopy. From the images, unique quantitative data can be deduced with high three‐dimensional resolution, such as the volume, shape, number, and intracellular location of the neutral lipid stores. We exemplify the strength and usability of the method for two cases: the impact on lipid storage of the nutritional condition (starvation and type of carbon source available) as well as of genetic modification of two fundamental metabolic regulation pathways involving carbohydrate and lipid storage (BCY1 and DGA1, LRO1, ARE1/2 deletions), respectively. While the impact of carbon source on the total cellular lipid volume was minimal, long‐term starvation induces a significant accumulation of lipid droplets. We also confirm that the lipid‐storage‐deficient mutant is indeed unable to synthesize lipid droplets, and that the inability of the bcy1‐mutant to store carbohydrates is compensated by a two‐fold increase in stored neutral lipids. We note that there is a significant cell‐to‐cell variability in neutral lipid storage in general, i.e. that there is a correspondence to the noise found for gene expression also in lipidomics. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation of functionalized magnetic nanoparticulate sorbents for rapid extraction of biphenolic pollutants from environmental samples
Authors: Ji Yongsheng , Liu Xiaoyan , Guan Min , Zhao Chuande , Huang Huayu , Zhang Haixia , Wang Chunming
Published: June 2009

A new solid‐phase extraction coupled with magnetic carrier technology was developed for extraction of bisphenol A (BPA) and diethylstilbestrol (DES) from water samples. The SPE sorbents, functionalized magnetic nanoparticles (Fe3O4@SiO2/β‐CD, core/shell), were synthesized in a two‐stage system. The material was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and a vibrating sample magnetometer. SPE extraction parameters, such as volume and pH of sample, adsorption time, and desorption conditions were optimized. Under selected conditions: 250 mL of water sample, 0.1 g of sorbents and elution with methanol (3 mL with 1% acetic acid), the extraction was completed in 25 min. SPE followed by HPLC was employed to determine BPA and DES in environmental samples. The developed method provided spiked recoveries of 80–105%, relative standard deviations of less than 7%, and LOD of BPA (20.0 ng/L) and DES (23.0 ng/L), respectively. The proposed method offered easy preparation of sorbents, rapid analysis, high enrichment yields, and reliable quantitative assay.
A capillary zone electrophoresis for determination of thiolic peptides in biological samples
Authors: Pérez‐Rama Mónica , Abalde Julio , Herrero Concepción , Suárez Cristina , Torres Enrique
Published: June 2009

A new method to improve the analyses of thiolic peptides (cysteine, γGlu‐Cys, glutathione, phytochelatins and desglycyl‐phytochelatins) derivatized with monobromobimane (mBrB) in complex biological samples by CZE is described. The method involves a SPE using Sep‐Pak Light C18 Cartridges after derivatization and a later CZE analysis. Elution of mBrB‐thiols was achieved with 10 mM HCl + 70% methanol v/v in deionised water. Electrophoretic parameters, such as BGE pH and concentration, different organic additives (methanol and trifluoroethanol), applied voltage and capillary length were studied in order to establish suitable analytical conditions. Optimum separation of the mBrB‐thiolic peptides was obtained with 100 mM sodium borate buffer at pH 7.60. The electrophoretic conditions were +15 kV, capillary length of 90 cm from inlet to detector (98 cm total length, 50 μm ID), samples were loaded into the capillary by hydrodynamic injection (50 mbar, 20 s) and detection was performed at 390 nm. The improved method showed good reproducibility, linearity and sensitivity. The LODs and LOQs estimated using a standard of GSH were 1.41 and 4.69 μM respectively.
A study on the kinetics of condensation reaction of cardanol and formaldehyde, part I
Authors: Sultania Minakshi , Rai J. S. P. , Srivastava Deepak
Published: June 2009

Novolac resins having cardanol‐to‐formaldehyde mole ratios of 1:0.4, 1:0.5, and 1:0.6 were prepared by using aromatic sulphonic acid as the catalyst at four different temperatures ranging between 90°C and 120°C, with an interval of 10°C. Free formaldehyde and free phenol contents were determined at regular time intervals to check the completion of the reaction. The synthesized novolacs were characterized by Fourier‐transform infrared spectroscopic analysis, nuclear magnetic resonance, and gel permeation chromatography. The reaction between cardanol and formaldehyde was found to follow second‐order kinetics. The overall rate constant (k) increased with the increase of temperature. On the basis of the value of k, various other activation parameters such as activation energy (Ea), change in enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) of the reaction were also evaluated. It was found that the condensation reaction of cardanol and formaldehyde with aromatic sulphonic acid was nonspontaneous and irreversible. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 559–572, 2009
The structure of compact disjointness preserving operators on continuous functions
Authors: Lin Ying‐Fen , Wong Ngai‐Ching
Published: June 2009

Let T be a compact disjointness preserving linear operator from C0(X) into C0(Y), where X and Y are locally compact Hausdorff spaces. We show that T can be represented as a norm convergent countable sum of disjoint rank one operators. More precisely, T = Σn δ ⊗hn for a (possibly finite) sequence {xn }n of distinct points in X and a norm null sequence {hn }n of mutually disjoint functions in C0(Y). Moreover, we develop a graph theoretic method to describe the spectrum of such an operator (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Faisceaux sans torsion et faisceaux quasi localement libres sur les courbes multiples primitives
Authors: Drézet Jean–Marc
Published: June 2009

This paper is devoted to the study of some coherent sheaves on non reduced curves that can be locally embedded in smooth surfaces. If Y is such a curve and n is its multiplicity, then there is a filtration C1 = C ⊂ C2 ⊂ … ⊂ Cn = Y such that C is the reduced curve associated to Y, and for every P ∈ C, if z ∈ OY,P is an equation of C then (zi) is the ideal of Ci in OY,P. A coherent sheaf on Y is called torsion free if it does not have any non zero subsheaf with finite support. We prove that torsion free sheaves are reflexive. We study then the quasi locally free sheaves, i.e., sheaves which are locally isomorphic to direct sums of the OCi.We define an invariant for these sheaves, the complete type, and prove the irreducibility of the set of sheaves of given complete type. We study the generic quasi locally free sheaves, with applications to the moduli spaces of stable sheaves on Y (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A processing method enabling the use of peak height for accurate and precise proton NMR quantitation
Authors: Hays Patrick A. , Thompson Robert A.
Published: June 2009

In NMR, peak area quantitation is the most common method used because the area under a peak or peak group is proportional to the number of nuclei at those frequencies. Peak height quantitation has not enjoyed as much utility because of poor precision and linearity as a result of inconsistent shapes and peak widths (measured at half height). By using a post‐acquisition processing method employing a Gaussian or line‐broadening (exponential decay) apodization (i.e. weighting function) to normalize the shape and width of the internal standard (ISTD) peak, the heights of an analyte calibration spectrum can be compared to the analyte peaks in a sample spectrum resulting in accurate and precise quantitative results. Peak height results compared favorably with ‘clean’ peak area results for several hundred illicit samples of methamphetamine HCl, cocaine HCl, and heroin HCl, of varying composition and purity. Using peak height and peak area results together can enhance the confidence in the reported purity value; a major advantage in high throughput, automated quantitative analyses. Published in 2009 by John Wiley & Sons, Ltd.
An enhanced constitutive model for crushable granular materials
Authors: Daouadji Ali , Hicher Pierre‐Yves
Published: June 2009

Studies in the past have tried to reproduce the mechanical behaviour of granular materials by proposing constitutive relations based on a common assumption that model parameters and parameters describing the properties, including gradation of individual grains are inevitably linked. However successful these models have proved to be, they cannot account for the changes in granular assembly behaviour if the grains start to break during mechanical loading. This paper proposes to analyse the relation between grading change and the mechanical behaviour of granular assembly. A way to model the influence of grain breakage is to use a critical state‐based model. The influence of the amount of grain breakage during loading, depending on the individual grain strength and size distribution, can be introduced into constitutive relations by means of a new parameter that controls the evolution of critical state with changes in grain size distribution. Experimental data from a calcareous sand, a quartz sand, and a rockfill material were compared with numerical results and good‐quality simulations were obtained. The main consequences of grain breakage are increased compressibility and a gradual dilatancy disappearance in the granular material. The critical state concept is also enriched by considering its overall relation to the evolution of the granular material. Copyright © 2009 John Wiley & Sons, Ltd.
On the determination of a set of material constants for a high‐cycle accumulation model for non‐cohesive soils
Authors: Wichtmann T. , Niemunis A. , Triantafyllidis Theodor
Published: June 2009

The paper discusses the determination of a set of constants for the high‐cycle accumulation model (HCA) proposed by the authors. The HCA model predicts permanent strains or excess pore water pressures in non‐cohesive soils due to a cyclic loading with a large number of cycles and with small to intermediate strain amplitudes. The laboratory tests necessary for the determination of the material constants and their analysis are explained in detail in this paper. Copyright © 2009 John Wiley & Sons, Ltd.
Optimizing fishbone aisles for dual‐command operations in a warehouse
Authors: Pohl Letitia M. , Meller Russell D. , Gue Kevin R.
Published: June 2009

Unit‐load warehouses store and retrieve unit‐loads, typically pallets. When storage and retrieval operations are not coordinated, travel is from a pickup and deposit (P&D) point to a pallet location and back again. In some facilities, workers interleave storage and retrieval operations to form a dual‐command cycle. Two new aisle designs proposed by Gue and Meller (“Improving the unit‐load warehouse.” In Progress in Material Handling Research: 2006. Material Handling Industry of America, Charlotte, NC, 2006) use diagonal aisles to reduce the travel distance to a single pallet location by approximately 10 and 20[percnt] for the two designs, respectively. We develop analytical expressions for travel between pallet locations for one of these—the fishbone design. We then compare fishbone warehouses that have been optimized for dual‐command to traditional warehouses that have been optimized in the same manner, and show that an optimal fishbone design reduces dual‐command travel by 10–15%. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 54: 389–403, 2009
Unsteady MHD flow due to noncoaxial rotations of micropolar fluid and an accelerated disk with partial slip condition
Authors: Shahzad F. , Hayat T. , Ayub M. , Asghar S.
Published: June 2009

An analysis is carried out to study the magnetohydrodynamic (MHD) flow of an incompressible micropolar fluid. The flow is induced by the noncoaxial rotations of constantly accelerated porous disk and a micropolar fluid. The influence of partial slip on the flow has been taken into consideration. Numerical solution of the governing flow problem is given by means of Newto's method. The important finding in this communication is the effects of partial slip on the velocity and microrotation vector. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
On comparison of series and numerical solutions for second Painlevé equation
Authors: Ellahi R. , Abbasbandy S. , Hayat T. , Zeeshan A.
Published: June 2009

This attempt presents the series solution of second Painlevé equation by homotopy analysis method (HAM). Comparison of HAM solution is provided with that of the Adomian decomposition method (ADM), homotopy perturbation method (HPM), analytic continuation method, and Legendre Tau method. It is revealed that there is very good agreement between the analytic continuation and HAM solutions when compared with ADM, HPM, and Legendre Tau solutions. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
2D internal flux compatibility equation of the flux Green element method for transient nonlinear potential problems
Authors: Taigbenu Akpofure E.
Published: June 2009

This article presents the derivation and implementation of the normal directional flux compatibility equation (relationship) at internal nodes when the Green element formulation that consistently provides accurate estimates of the primary variable, and its normal directional derivative (normal flux) is applied in 2D heterogeneous media to steady and transient potential problems. Such a relationship is required to resolve the closure problem due to having fewer integral equations than the number of unknowns at internal nodes. The derivation of the relationship is based on Stokes' theorem, which transforms the contour integral of the normal directional fluxes into a surface integral that is identically zero. The numerical discretization of the compatibility equation is demonstrated with four numerical examples using the six‐node quadratic triangular and the four and eight‐node rectangular elements. The incorporation of triangular elements into the current formulation demonstrates that the internal compatibility equation can be successfully implemented on irregular grids. The direct calculation of the fluxes significantly enhances the accuracy of the formulation, so that high accuracy, exceeding that of the finite element method, is achieved with very coarse spatial discretization. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Preparation and characterization of a composite PDMS membrane on CA support
Authors: Sadrzadeh Mohtada , Saljoughi Ehsan , Shahidi Kazem , Mohammadi Toraj
Published: June 2009

Polydimethylsiloxane (PDMS) is the most commonly used membrane material for the separation of condensable vapors from lighter gases. In this study, a composite PDMS membrane was prepared and its gas permeation properties were investigated at various upstream pressures. A microporous cellulose acetate (CA) support was initially prepared and characterized. Then, PDMS solution, containing crosslinker and catalyst, was cast over the support. Sorption and permeation of C3H8, CO2, CH4, and H2 in the prepared composite membrane were measured. Using sorption and permeation data of gases, diffusion coefficients were calculated based on solution‐diffusion mechanism. Similar to other rubbery membranes, the prepared PDMS membrane advantageously exhibited less resistance to permeation of heavier gases, such as C3H8, compared to the lighter ones, such as CO2, CH4, and H2. This result was attributed to the very high solubility of larger gas molecules in the hydrocarbon‐based PDMS membrane in spite of their lower diffusion coefficients relative to smaller molecules. Increasing feed pressure increased permeability, solubility, and diffusion coefficients of the heavier gases while decreased those of the lighter ones. At constant temperature (25°C), empirical linear relations were proposed for permeability, solubility, and diffusion coefficients as a function of transmembrane pressure. C3H8/gas solubility, diffusivity, and overall selectivities were found to increase with increasing feed pressure. Ideal selectivity values of 9, 30, and 82 for C3H8 over CO2, CH4, and H2, respectively, at an upstream pressure of 8 atm, confirmed the outstanding separation performance of the prepared membrane. Copyright © 2009 John Wiley & Sons, Ltd.
Studies on UV‐stability of poly(MMA‐co‐M12‐co‐BPMA)/TiO2composite particles prepared by ultrasonically initiated emulsion polymerization
Authors: Zou Jiangpeng , Jiang Long , Nguyen Thien Phap , Dan Yi
Published: June 2009

In this paper, poly(methyl methacrylate‐co‐sodium sulfopropyl lauryl maleate‐co‐2‐hydroxy‐4‐(3‐methacryloxy‐2‐hydroxylpropoxy) benzophenone)/TiO2 (i.e., poly(MMA‐co‐M12‐co‐BPMA)/TiO2) composite particles were prepared by ultrasonically initiated emulsion polymerization. To study the dispersion and UV‐stability of the composite particles, laser diffraction particle size analyzer (LDPSA), ultraviolet‐visible absorption spectroscopy (UV‐vis), UV‐vis diffuse reflectance spectroscopy (DRS), differential scanning calorimeter (DSC), and the weight loss measurement were used. The results indicate that the dispersion of the poly(MMA‐co‐M12‐co‐BPMA)/TiO2 composite particles prepared by ultrasonically initiated emulsion polymerization is good. And the composite particles can absorb UV light; the ultraviolet absorption strength of poly(MMA‐co‐M12‐co‐BPMA) grafted onto the surface of TiO2 has not changed after UV irradiation while that of PMMA changed significantly. The UV absorption strength, weight loss, and Tg changes are in the order PMMA> poly(MMA‐co‐M12‐co‐BPMA) >PMMA grafted onto TiO2> poly(MMA‐co‐M12‐co‐BPMA) grafted onto TiO2. These results show that the ultrasonically initiated emulsion polymerization will enhance the UV stability of composite particles, and the UV‐stability of PMMA can be enhanced by the introduction of the organic UV‐stabilizer BPMA and the inorganic UV‐stabilizer titanium dioxide into the PMMA chains by covalent bond, and the effect of the BPMA and the TiO2 used together is better than that used, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
pH‐induced on–off switching of polycarbonate track‐etched membranes by plasma‐induced surface grafting
Authors: Li Chunyan , Cao Bing , Wang Wencai , Li Qifang , Zhao Jing , Zhang Liqun
Published: June 2009

Surface functionalization of the plasma‐pretreated polycarbonate (PC) track‐etched membranes via plasma‐induced thermally graft copolymerization of acrylic acid (AAc) was carried out. The resulting PC membranes with grafted AAc side chains were characterized by X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis. The morphology of the PC membranes was studied by scanning electron microscopy (SEM). The results showed that the grafted PAAc polymers were formed uniformly inside the pores throughout the entire membrane thickness. With increase in the pore‐filling ratio, the pore diameters of PAAc‐grafted membranes became smaller. The PC‐g‐PAAc membranes exhibit rapid and reversible response of the flux to the environmental pH as pH is switched between 3 and 9. Between pH 3.5 and 5.5, the membranes demonstrate a pH‐valve function as the carboxyl group changes from neutral to charged with a corresponding variation in chain configuration. Copyright © 2009 John Wiley & Sons, Ltd.
Antioxidant and spectroscopic studies of crosslinked polymers synthesized by grafting polymerization of ferulic acid
Authors: Parisi Ortensia Ilaria , Puoci Francesco , Iemma Francesca , De Luca Giuseppina , Curcio Manuela , Cirillo Giuseppe , Spizzirri Umile Gianfranco , Picci Nevio
Published: June 2009

A novel, simple synthetic strategy for the preparation of crosslinked polymers with significant antioxidant properties is proposed. Ferulic acid (FA), a well‐known antioxidant compound, due to its reactivity toward free radical process, was inserted into a polymeric network with methacrylic acid (MAA) and ethylene glycole dimethacrylate acting as comonomer and crosslinker, respectively. All the reactants were simultaneously mixed in the polymerization feed and one‐pot radical reaction was carried out. Irregular microparticles were prepared by bulk polymerization and microspheres by precipitation polymerization. The materials were characterized by nuclear magnetic resonance–magic angle spinning (NMR‐MAS) studies, to verify effective FA insertion into polymeric networks, and by morphological, dimensional analyses, and water absorption measurement to study their superficial and swelling properties, respectively. Antioxidant properties of materials were evaluated by linoleic acid emulsion system–thiocyanate assay, determination of scavenging activity on DPPH radicals, determination of available phenolic groups in polymeric matrices, and determination of total antioxidant capacity. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison of CpG island hypermethylation and repetitive DNA hypomethylation in premalignant stages of gastric cancer, stratified for Helicobacter pylori infection
Authors: Park Seog‐Yun , Yoo Eun J , Cho Nam‐Yun , Kim Nayoung , Kang Gyeong H
Published: June 2009

CpG island hypermethylation and genomic DNA hypomethylation are found not only in gastric cancers but also in associated premalignant lesions. Helicobacter pylori infection induces aberrant CpG island hypermethylation in gastric mucosae. However, little is known about the relationship between H. pylori infection and aberrant methylation in premalignant lesions. The present study characterized methylation changes in a subset of genes and repetitive DNA elements (ALU, LINE‐1, SAT2) and examined their relationship with H. pylori infection in premalignant lesions of gastric cancers. We performed MethyLight analysis of 25 genes and SAT2 and COBRA analysis of ALU and LINE‐1 in 212 gastric tissue samples. H. pylori infection was closely associated with enhanced hypermethylation of CpG island loci in chronic gastritis samples, but this association was not found among intestinal metaplasias, gastric adenomas and gastric cancers. The number of methylated genes was greater in intestinal metaplasia and gastric adenoma samples than in chronic gastritis samples, regardless of H. pylori infection. Methylation of repetitive DNA elements in gastric lesions generally decreased with progression of the gastric lesion along the multistep carcinogenesis. No difference was noted in the number of methylated genes in chronic gastritis or intestinal metaplasia between gastric cancer patients and non‐cancer subjects. In conclusion, we found that there was no enhanced CpG island hypermethylation in gastric cancer and premalignant lesions in association with H. pylori infection and our findings suggest that CpG island hypermethylation and repetitive DNA hypomethylation are enhanced with progression of the gastric lesion through the multistep carcinogenesis, regardless of the status of H. pylori infection. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Commentary: The federal ‘Prenatally and Postnatally Diagnosed Conditions Awareness Act’
Authors: Reilly Philip R.
Published: June 2009

The recently enacted federal law, the ‘Prenatally and Postnatally Diagnosed Conditions Awareness Act’ (United States Public Law 110–374) seeks to improve opportunities for parents and pregnant women to anticipate and understand the likely life course of children born with Down syndrome and other (unspecified) conditions. The law is in part a response to the continued growth of prenatal screening and testing. For example, the American College of Obstetricians and Gynecologists' Practice Bulletin 77 recommends that ‘Screening and invasive diagnostic testing for aneuploidies be available to all women who present for prenatal care before 20 weeks of gestation regardless of maternal age.’ Emerging technologies anticipate an era in which the scope of prenatal screening and testing will be much larger than it is today. Inevitably, more women will find themselves facing the hard question of whether to continue or end a pregnancy in which a fetus has been found to have a significant abnormality. While the new federal law is not likely to have a major impact on obstetric practice, it may be a harbinger of renewed wide‐scale public debate concerning the ethics of prenatal screening. Copyright © 2009 John Wiley & Sons, Ltd.
A designed chimeric cyanovirin‐N homolog lectin: Structure and molecular basis of sucrose binding
Authors: Koharudin Leonardus M. I. , Furey William , Gronenborn Angela M.
Published: June 2009

The NMR and X‐ray structures of a designed chimeric cyanovirin‐N homolog (CVNH) protein were determined. The individual halves of the structure are similar to their counterparts in the parent proteins, with domains A and B resembling the structures of TbCVNH and NcCVNH, respectively. No significant differences between the solution and crystal conformations were observed, although details in loop conformations and distinct crystal packing‐induced features are present. Carbohydrate binding studies by NMR revealed affinity and specificity for Glcα(1‐2)Frc and Manα(1‐2)Man, and the parental half that is devoid of any sucrose affinity in NcCVNH was transformed into a genuine sucrose binding site in the context of the chimera. The atomic details of sugar recognition are seen in the crystal structure of the protein with two bound Glcα(1‐2)Frc molecules. Both sugars exhibit different conformations around the glycosidic bond and engage in unique hydrogen bonding networks in the two sites. Although the protein is able to bind two Manα(1‐2)Man molecules, a property associated with HIV‐inactivation, no anti‐HIV activity was observed for the hybrid protein. These results provide the structural basis for sugar recognition in the CVNH family and aid in deciphering the relationship between sugar binding and anti‐HIV activity. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Fundamental absorption edge and near‐absorption edge properties of PLZT thin films
Authors: Khodorov A. , Gomes M. J. M.
Published: June 2009

Lanthanum‐doped lead zirconate titanate (PLZT) thin films were fabricated by sol–gel, as well as, pulsed‐laser deposition methods on sapphire (0001) and MgO (100) substrates, respectively. The cell parameters of the films were calculated with the help of a whole‐pattern fitting procedure. The study of their optical properties revealed the fractal behavior of the absorption coefficient near the absorption edge (Eg). For laser‐ablated and sol–gel‐derived films, Eg was estimated to be 3.61 and 3.65 eV, respectively. This shift of Eg was suggested to relate to a difference in strain values and the volume‐deformation potential was estimated to be −2.4 eV. The strong shift of Eg in the thin films in comparison to bulk PLZT was also observed. This shift could not only be attributed to the presence of strain, but could also be due to increased disorder and polarization fluctuations.
In situ analysis of optoelectronic properties of dislocations in ZnO in TEM observations
Authors: Ohno Yutaka , Taishi Toshinori , Yonenaga Ichiro
Published: June 2009

Extended defects acting as non‐radiative recombination center or those acting as radiative one were, respectively, studied by transmission electron microscopy under the illumination of a monochromatic light or cathodoluminescence spectroscopy combined with light illumination. By means of this method, defect levels associated with dislocations in ZnO, which were introduced at elevated temperatures above 923 K, were determined. It was proposed that (i) a screw dislocation, presumably acting as non‐radiative recombination center, glides under the illumination of a light with photon energy above 2.48–2.61 eV, due to an electron–hole recombination at a defect level of 2.48–2.61 eV depth, and (ii) a mixed dislocation acts as radiative recombination center with a defect level of 3.1 eV depth.
Helium implantation into 4H‐SiC
Authors: Barbot Jean François , Leclerc Stéphanie , David Marie‐Laure , Oliviero Erwan , Montsouka Romaric , Pailloux Frederic , Eyidi Dominique , Denanot Marie‐Françoise , Beaufort Marie‐France , Declémy Alain , Audurier Valérie , Tromas Christophe
Published: June 2009

The paper provides the properties of single crystalline 4H‐SiC under helium implantation at temperatures of implantation up to 750 °C and fluences in the range 5 × 1015–1 × 1017 cm−2. The microstructure evolution was studied by transmission electron microscopy cross‐section and X‐ray diffraction experiments. The mechanical property changes were investigated by using nanoindentation tests followed by atomic force microscopy observations and by using tribological tests. At elevated temperature of implantation and/or in the low fluence regime at room temperature where only the strained state of SiC is obtained, SiC becomes more resistant to crack formation but no significant change in mechanical properties is seen. At room temperature with increasing fluence the damage accumulation leads to the amorphous state for which a strong degradation of the mechanical properties is observed. At elevated temperature of implantation, amorphization is avoided and a thermally activated saturation of the strain is observed in the near surface region whereas defect accumulation occurs near the maximum of damage. Upon annealing subsequent to room temperature implantation, the near surface strain progressively relaxes while the helium ions agglomerate into platelets around the maximum of strain. These platelets evolve into bubble clusters at temperatures where the vacancies become mobile. Under particular conditions of implantation (high fluence and elevated temperature) the swelling of the surface increases during annealing due to the growth of bubbles and the formation of stacking faults resulting from the migration of interstitials towards the maximum of damage.
Bragg–(Bragg)m–Laue diffraction and its interference fringe
Authors: Hirano Kenji , Fukamachi Tomoe , Yoshizawa Masami , Negishi Riichirou , Hirano Keiichi , Kawamura Takaaki
Published: June 2009

X‐Ray rocking curves from side surface of a thin plane‐parallel Ge crystal are measured under the condition where the dispersion of the refracted angle is quite large. In the diffracted beams from side surface are observed, which are analysed by using Wagner's approach for Bragg–(Bragg)m–Laue case. The origin of the fringes is explained by the interference between diffraction beams in Bragg–Laue case and that in Bragg–Bragg–Laue case.
Reflection of femtosecond pulses from soft X‐ray free‐electron laser by periodical multilayers
Authors: Ksenzov D. , Grigorian S. , Hendel S. , Bienert F. , Sacher M. D. , Heinzmann U. , Pietsch U.
Published: June 2009

Recent experiments on a soft X‐ray free‐electron laser (FEL) source (FLASH in Hamburg) have shown that multilayers (MLs) can be used as optical elements for highly intense X‐ray irradiation. An effort to find most appropriate MLs has to consider the femtosecond time structure and the particular photon energy of the FEL. In this paper we have analysed the time response of ‘low absorbing’ MLs (e.g. such as La/B4C) as a function of the number of periods. Interaction of a pulse train of Gaussian shaped sub‐pulses using a realistic ML grown by electron‐beam evaporation technique has been analysed in the soft‐X‐ray range. The structural parameters of the MLs were obtained by reflectivity measurements at BESSY II and subsequent profile fittings.
A furnace for coherent beam transmission topography applied to ferroelectric crystals
Authors: Pernot Petra , Gorges Bernard , Vitoux Hugo , Kluender Rafael , Masiello Fabio , Baruchel José
Published: June 2009

We describe a small furnace for transmission diffraction imaging studies, designed to (i) go up to 800 °C while having a temperature gradient as reduced as possible on a platelet‐shaped insulating sample, (ii) allow a large and homogeneous beam to be transmitted/diffracted and (iii) preserve the coherence properties of these transmitted and diffracted beams, which are recorded at variable crystal‐to‐detector distances (typically 2–200 cm). We report experiments, to test the temperature gradient, on the ferroelectric to paraelectric transition of BaTiO3, and to check the preservation of the coherence properties of the beam, which include the observation of ferroelectric domains in a poled LiNbO3 crystal.
X‐ray diffuse scattering effects from Coulomb‐type defects in multilayered structures
Authors: Olikhovskii S. I. , Molodkin V. B. , Skakunova E. S. , Kislovskii E. N. , Fodchuk I. M.
Published: June 2009

The theoretical X‐ray diffraction model starting from Takagi–Taupin equation has been developed for the description of coherent and diffuse components of the rocking curve (RC) measured from the multilayered crystal structure with randomly distributed Coulomb‐type defects in all the layers and substrate. The model describes both diffuse scattering (DS) intensity distribution and influence of DS on attenuation and angular redistribution of the coherent X‐ray scattering intensity. By analyzing the total measured RC with using the proposed diffraction model, the chemical compositions, strains, and characteristics of dislocation loops in layers and substrate of the multilayered structure with InGaAsN/GaAs single quantum well have been determined.
Interdiffusion in Ge rich SiGe/Ge multilayers studied by in situ diffraction
Authors: Meduňa M. , Caha O. , Keplinger M. , Stangl J. , Bauer G. , Mussler G. , Grützmacher D.
Published: June 2009

We report on the investigation of diffusion properties of SiGe/Ge multiple quantum well (MQW) structures with period of 24 nm grown strain symmetrized on relaxed SiGe buffers on Si (001) substrates by molecular beam epitaxy. During in situ annealing, X‐ray diffraction experiments were performed on series of MQW structures with average Ge contents of about 70 and 90% using reciprocal space mapping around the (224) reciprocal lattice point. The reciprocal space maps were obtained at elevated temperatures at the ESRF for temperatures from about 600 to 800 °C. The temperatures, where interdiffusion becomes observable, is in the range from 680 to 780 °C for xGe = 0.7 and from 650 to 720 °C for xGe = 0.9. The diffusion parameters were obtained from the analysis of the decay of the periodic satellites in the recorded intensity maps.
Observation of dislocations in hen egg‐white lysozyme crystals by synchrotron monochromatic‐beam X‐ray topography
Authors: Mukobayashi Yu. , Kitajima Natsuko , Yamamoto Yu. , Kajiwara Kentaro , Sugiyama Hiroshi , Hirano Keiichi , Kojima Kenichi , Tachibana Masaru
Published: June 2009

Dislocations in large hen egg‐white lysozyme (HEWL) crystals with tetragonal and orthorhombic forms were investigated by means of synchrotron monochromatic‐beam X‐ray topography. For the tetragonal form, not only screw dislocations but also edge ones are found to be included in predominant ones parallel to 〈110〉 directions. In addition, curved dislocations that can be related to (001)〈110〉 slip system are observed at the crystal edges. For the orthorhombic form, predominant edge dislocations with [001] Burgers vector are stereoscopically observed. It is clarified that they are generated at or around the nucleus centre or sector boundary.