bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation/Inhibition Effects during the Coelectrodeposition of PtAg Nanoparticles: Application for ORR in Alkaline Media
Authors: Schwamborn Stefanie , Stoica Leonard , Schuhmann Wolfgang
Published: May 2011

PtAg bimetallic nanoparticles for oxygen reduction reaction (ORR) in alkaline media were prepared by pulse electrodeposition (PED). During PED the reduction of Ag+ ions predominates, thus an increased Ag content in the co‐deposit is accomplished. The mechanism for this anomalous co‐deposition was elucidated by potential pulse experiments, which revealed that nuclei formation mainly occurs via the reduction of Pt2+ ions. The growth of the particles is diffusion controlled leading to the formation of a Ag shell covering a PtAg alloyed region. However, the shell is not growing homogeneously on the PtAg alloy. Hence, regions of the PtAg alloy are exposed, which exhibit an enhanced ORR activity compared to a pure Ag surface.
Long‐Term Stable Silver Subsurface Ion‐Exchanged Glasses for SERS Applications
Authors: Simo Anne , Joseph Virginia , Fenger Robert , Kneipp Janina , Rademann Klaus
Published: May 2011

We report on the formation of silver subsurface ion‐exchanged metal oxide (silver SIMO) glasses and their surface‐enhanced Raman scattering (SERS) activity. The samples were prepared by a combined thermal and chemical three‐step methodology and characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental electron scanning microscopy (ESEM), and UV/Vis spectroscopy. This unique method provides SERS substrates with protection against contamination and strong, reliable and reproducible SERS enhancement. The Raman enhancement factors of the long‐term stable SIMO glasses were estimated to approximately 107.
Development of Crystallographic Texture and In‐Grain Misorientation in CVD‐Produced Single and Polycrystalline Diamond
Authors: Mohapatra Dipti Ranjan , Jain Lokendra , Rai Padmnabh , Hazra Kiran Shankar , Samajdar Indradev , Misra Devi Shanker
Published: May 2011

Extensive bulk and micro‐texture measurements are used to characterize single and polycrystalline diamond thin films of different film thicknesses produced using CVD. With increasing film thickness, texturing improves and in‐grain misorientation drops. This is observed for both single and polycrystalline films. Improved texturing in polycrystalline diamond can be rationalized from growth selection/advantage, however explanation(s) on the in‐grain misorientation development and its relationship with texturing, if any, remain pending.
Synthesis of Benzo[c]azocanones and Indeno[1,2‐b]pyrroles from Oxoindanecarboxylates
Authors: Behler Florian , Habecker Florian , Saak Wolfgang , Klüner Thorsten , Christoffers Jens
Published: May 2011

Ethyl 1‐oxo‐indane‐2‐carboxylate with a 1,4‐diketone motif gave a benzo[c]azocane‐1‐one derivative ― an eight‐membered ring lactam ― in a bismuth‐mediated ring‐expansion reaction with methylamine (40 % yield). Yields with other primary amines were significantly lower. The ester function in the heterocyclic product could be saponified to give the free carboxylic acid, which was further amidated with para‐bromoaniline. The molecular structure of the latter was established by X‐ray single‐crystal analysis. Benzo[c]azocanones exist in two diastereoisomeric conformations, causing double signal sets in the NMR spectra. Slow interconversion between these conformers was proved by EXSY NMR spectroscopy. Moreover, a conformational analysis by DFT calculations revealed the two diastereoisomers to be boat conformers that interconvert through a twist conformer. The maximum barrier for this process was calculated to be approximately 70 kJ/mol. Reaction of the corresponding methyl 1‐oxoindane‐2‐carboxylate with methylamine gave the benzo[c]azocanone in lower yield. A spirolactam and an indeno[1,2‐b]pyrrole were formed as further products. When using an indanone‐derived 1,4‐diketone without an ester function, several primary amines could be used in a bismuth‐catalyzed Paal–Knorr reaction to give indeno[1,2‐b]pyrrole derivatives with up to quantitative yields in several cases. Attempts to synthesize a caprolactam derivative from a cyclobutanone derived β‐oxo ester with 1,4‐diketone motif were unsuccessful.
Efficient and Stereocontrolled Construction of Homo‐ and Heterogeneously 4‐ and 6‐Sulfated Biotinylated Chondroitin Oligomers
Authors: Vibert Aude , Lopin‐Bon Chrystel , Jacquinet Jean‐Claude
Published: May 2011

An efficient and stereocontrolled construction of homo‐ and heterogeneously 4‐ and 6‐sulfated biotinylated chondroitin oligomers has been investigated and is reported for the first time. This procedure allowed the preparation of oligomeric chondroitin derivatives with sulfate groups at specific positions; these should be useful probes for the study of the starting point of the polymerization reaction as well as the substrate specificity of sulfotransferases involved in the biosynthesis of chondroitin sulfate chains.
Chemoenzymatic Synthesis of the C3–C11‐Fragment of Borrelidin
Authors: Theurer Matthias , El Baz Yana , Koschorreck Katja , Urlacher Vlada B. , Rauhut Guntram , Baro Angelika , Laschat Sabine
Published: May 2011

The ex‐chiral pool synthesis of the Theodorakis C3–C11 fragment of borrelidin (1) by a chemoenzymatic approach in nine steps and 12 % overall yield starting from enantiopure methyl‐branched preen gland wax esters is described. In the initial reaction, the wax ester was (ω‐1)‐hydroxylated regioselectively by using a mutant of the cytochrome P450 monooxygenase CYP102A1 as biocatalyst. The fourthstereocenter in the C3–C11 fragment was generated by chiral auxiliary mediated alkylation. In order to explain the experimental results of the alternative epimerization of an all‐syn polypropionate, quantum chemical calculations were performed at the B3LYP/cc‐pVDZ level.
Aminophosphines derived from N‐phenylpiperazine and N‐ethylpiperazine: Synthesis, oxidation reactions, and molybdenum complexes
Authors: Sarıöz Özlem , Öznergiz Sena , Saraçoglu Hanife , Büyükgüngör Orhan
Published: May 2011

Functionalized aminophosphine of the type Ph2PNR2 (1,2) have been synthesized by treating Ph2PCl with N‐phenylpiperazine or N‐ethylpiperazine. Oxidation of these ligands with aqueous hydrogen peroxide, elemental sulfur or selenium afforded the corresponding phosphine oxides 3,4, sulfides 5,6, and selenides 7,8 in good yields. The molybdenum complexes of the aminophosphines have been obtained. All new compounds were fully characterized by IR, NMR, and microanalysis, and the molecular structures of two representative compounds were determined by single‐crystal X‐ray crystallography. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:679–686, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20733
Valuing states from multiple measures on the same visual analogue sale: a feasibility study
Authors: Rowen Donna , Brazier John , Tsuchiya Aki , Alava Mónica Hernández
Published: May 2011

Previous methods of empirical mapping involve using regressions on patient or general population self‐reported data from datasets involving two or more measures. This approach relies on overlap in the descriptive systems of the measures and assumes it is appropriate to use different measures on the same population, which may not always be the case. This paper presents a feasibility study for a new approach to mapping between preference‐based measures (PBM) using general population visual analogue scale (VAS) values as a common yardstick. We use data from a valuation study of 502 members of the UK general population, where, using ranking and VAS tasks, interviewees simultaneously valued health states defined by three of six PBM: EQ‐5D (generic), SF‐6D (generic), HUI2 (generic for children and adults), AQL‐5D (asthma specific), OPUS (social care specific) and ICECAP (capabilities). Regression techniques are used to estimate the relationship between these VAS values and the original value set (i.e. ‘tariff’). These results are subsequently used to estimate the relationship between all six PBM to enable ‘value‐based mapping’ between measures. This new method of mapping potentially has a useful role in evidence synthesis and cross programme comparisons in studies using different measures. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of inundation areas resulting from the diversion of an extreme discharge towards the sea: case study in Tabasco, Mexico
Authors: Pedrozo‐Acuña Adrián , Mariño‐Tapia I , Enriquez C , Medellín Mayoral Gabriela , González Villareal Fernando J.
Published: May 2011

This investigation comprises the hydraulic characterisation of a river located in the Mexican State of Tabasco, including the performance of its flood plain under the action of an extreme river discharge. This is done through the combination of a high‐quality validation dataset, remote sensing information, and a standard 2D numerical model. The dataset was collected during an intensive field campaign that took place in August 2009. In particular, in situ measurements of river discharge, bathymetry, water level, and velocities through a whole tidal cycle are employed along with multi‐spectral satellite imagery. The purpose of this study is twofold. Firstly, the integrated approach comprising the combination of a 2D hydrodynamic model, high‐quality in situ measurements and satellite imagery reduce the uncertainty in the model parameterisation and results. Secondly, it is shown that freely available sources of information, such as the Shuttle Radar Topographic Mission (SRTM) data can be processed and utilized in 2D hydraulic models. This is particularly important in countries where high‐resolution elevation data is not yet available. It is demonstrated that the selected approach is useful when the study of possible consequences in a flood plain induced by an extreme flood discharge are sought. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of bacterial adhesion and cellular proliferation on newly developed three‐dimensional scaffolds manufactured by rapid prototyping technology
Authors: Al‐Ahmad A. , Schubert C. , Carvalho C. , Thoman Y. , Wittmer A. , Metzger M. , Hellwig E. , Swieszkowski W. , Wiedmann‐Al‐Ahmad M.
Published: May 2011

Scaffolds used in the field of tissue engineering should facilitate the adherence, spreading, and ingrowth of cells as well as prevent microbial adherence. For the first time, this study simultaneously deals with microbial and tissue cell adhesion to rapid prototyping‐produced 3D‐scaffolds. The cell growth of human osteosarcoma cells (CAL‐72) over a time period of 3–11 days were examined on three scaffolds (PLGA, PLLA, PLLA‐TCP) and compared to the adhesion of salivary microorganisms and representative germs of the oral flora (Porphyromonas gingivalis, Prevotella nigrescens, Candida albicans, Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguinis). Scanning electron microscopy (SEM), cell proliferation measurements, and determination of the colony forming units (CFU) were performed. The cell proliferation rates on PLLA and PLLA‐TCP after 3, 7, and 11 days of cultivation were higher than on PLGA. On day 3 the proliferation rates on PLLA and PLLA‐TCP, and on day 5 on PLLA‐TCP, proved to be significantly higher compared to that of the control (culture plate). The strain which showed the most CFUs on all of the investigated scaffolds was P. gingivalis, followed by E. faecalis. No significant CFU differences were determined examining P. gingivalis among the biomaterials. In contrast, E. faecalis was significantly more adherent to PLGA and PLLA compared to PLLA‐TCP. The lowest CFU values were seen with C. albicans and P. nigrescens. Salivary born aerobic and anaerobic microorganisms adhered significantly more to PLGA compared to PLLA‐TCP. These results supported by SEM point out the high potential of PLLA‐TCP in the field of tissue engineering. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011.
Modulation of immunological properties of allogeneic mesenchymal stem cells by collagen scaffolds in cartilage tissue engineering
Authors: Yuan Tun , Li Kuifeng , Guo Likun , Fan Hongsong , Zhang Xingdong
Published: May 2011

Influence of the structures of some collagen scaffolds on immunological properties of the seeded allogeneic mesenchymal stem cells (MSCs) was studied in this article. Hydrogels, sponge, and membrane were prepared from type‐I collagen. These scaffolds were seeded with neonatal rabbit MSCs and cultured for different periods. Changes of the immunological properties associated with different scaffolds were analyzed and compared. It was found that the expression of major histocompatibility complex (MHC) class I and II molecules on MSCs increased gradually in all scaffolds, but the least increment was recorded in hydrogels. Mixed lymphocyte reactions (MLR) showed that the MSC‐hydrogel constructs invoked considerably low allogeneic lymphocytes proliferation. Even in presence of interferon‐γ (IFN‐γ), the hydrogels with higher concentration gave comparatively lower increment of MHC‐II expression and allogeneic lymphocytes proliferation. These results suggest that different scaffold structures may provide different microenvironments and extents of isolation from the host immune system for the seed cells, thereby affecting their immunological properties. Therefore, scaffold structures may modulate the immunological properties of tissue‐engineered cartilage with allogeneic cells. Hydrogels, especially which were prepared from higher collagen concentrations, were found to be a promising scaffold structure, from the perspective of avoiding severe immune rejection. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011.
Sonographic findings in a case of polyneuropathy associated with POEMS syndrome
Authors: Yanik Bahar , Conkbayir ISIK , Keyik Bahri , Yoldas Tahir Kurtulus
Published: May 2011

Polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes (POEMS) syndrome is a rare multi‐system disease. We describe the ultrasonography (US) and color Doppler ultrasonography (CDUS) findings of peripheral neuropathy in a patient with POEMS syndrome. In US examination, peripheral nerves were found to be diffusely thickned in both upper limbs. CDUS imaging showed arterial blood flow with low systolic peaks on the nerves. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 2011
Pararectal mass: An atypical location of splenosis
Authors: Akay Sinan , Ilica Ahmet Turan , Battal Bilal , Karaman Bulent , Guvenc Inanc
Published: May 2011

Splenosis is the autotransplantation of splenic tissue resulting from the dissemination of cells from the pulp of the spleen after splenic injury or splenectomy. Implants can be found anywhere in the peritoneal cavity, especially on the serosal surfaces of small and large bowel, in the mesentery and diaphragm, implanted in visceral organs, within the thorax and brain, and in surgical scars and may vary in number, shape, and size. We described the sonographic, computed tomography and magnetic resonance imaging findings of pararectal splenosis in a 23‐year‐old man. The lesions appeared as multiple, well‐circumscribed, small, round, homogenously solid masses of different sizes at the retrovesical and pelvic region detected during the imaging workup of Behçet disease. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 40:443–447, 2012
An oxidative alkylamination of 1,3,7‐triazapyrenes in the aqueous medium
Authors: Borovlev Ivan , Demidov Oleg , Saigakova Nadezhda , Pisarenko Sergey , Nemykina Olesya
Published: May 2011

1,3,7‐Triazapyrene and 2‐methyl‐1,3,7‐triazapyrene have shown to react with a wide range of alkylamines in the presence of an oxidant (K3Fe(CN)6) in the water solution at room temperature to give rise to the corresponding 6‐mono‐alkyl(dialkyl)amino‐ and 6,8‐bis‐dialkylamino derivatives. J. Heterocyclic Chem., (2011).
Solvent‐free synthesis of new 2,4,6‐triarylpyridines catalyzed by a Brønsted acidic ionic liquid as a green and reusable catalyst
Authors: Behmadi Hossein , Naderipour Shima , Saadati Seyed Mahdi , Barghamadi Mohammad , Shaker Mohammad , Tavakoli‐Hoseini Niloofar
Published: May 2011

Some new 4‐(aryl)‐2,6‐di‐2‐naphthylpyridines and 4‐(aryl)‐2,6‐di‐2‐thienylpyridines have been prepared through three‐component condensation of 2‐acetylnaphthalene or 2‐acetylthiophene, aromatic aldehydes, and ammonium acetate in presence of 1‐(4‐sulfonylbutyl) pyridinium hydrogensulfate [(CH2)4SO3HPy][HSO4], a Brønsted acidic ionic liquid as a green and reusable catalyst in solvent‐free conditions. Also some new 4,4'‐(1,4‐phenylene)‐bis‐(2,6‐di‐aryl pyridine) was prepared. J. Heterocyclic Chem., (2011).
Phenylaminopropyl‐functionalized stationary phase for open‐tubular capillary electrochromatography of alkaloids and aromatic acids
Authors: Lin Xucong , Tan Jingjing , Xu Shengmei , Xie Zenghong
Published: May 2011

A multi‐functional open‐tubular (OT) column covalently modified with [3‐(phenylamino)propyl]trimethoxysilane (PPTMS) via a single‐step silanization reaction has been developed, and employed for alkaloids and aromatic acids analytes by CEC. Both anodic and cathodic EOF could be gained in the PPTMS‐bonded column, and anodic EOF was exhibited when the pH of running buffer was less than 8.0. Using thiourea as the EOF marker, a satisfactory column stability was denoted, and the RSD values for migration time and peak area were gained at 0.5 and 3.7% (intra‐day, n=5), 1.7 and 5.6% (inter‐day, n=3), 3.9 and 5.8% (column‐to‐ column, n=16 in four batches). With anodic EOF mode (pH=2.0 of 10 mmol/L phosphate buffer), favorable separations of cationic alkaloids (viz. uridine, adenosine, cytidine, adenine, cytosine) were successfully achieved with column efficiencies ranging from 95 000 to 187 000 plates/m, and the undesired adsorption on the inter‐wall of capillary column could be avoided. Besides, six anionic aromatic acids could be also separated efficiently in the co‐electroosmotic mode with anodic EOF. And high efficiencies ranged from 176 000 to 235 000 plates/m were gained with a good repeatability. PPTMS‐bonded capillary column might be used as an alternative functional medium to physical coating capillary column for the analyses of aromatic organic acids and bases.
Engineering of Phenylboronic Acid Based Glucose‐Sensitive Microgels with 4‐Vinylpyridine for Working at Physiological pH and Temperature
Authors: Farooqi Zahoor H. , Wu Weitai , Zhou Shuiqin , Siddiq Mohammad
Published: May 2011

Glucose‐sensitive p(NIPAM‐4‐VP‐PBA) microgels with different 4‐VP content are synthesized by the functionalization of p(NIPAM‐4‐VP‐AA) microgels with 3‐aminophenylboronic acid. The glucose‐, pH‐, and thermosensitive behavior of the microgels are investigated using DLS. The feeding content of the hydrophilic 4‐VP group increases the hydrodynamic radius and volume phase transition temperature of the resultant microgel. The effect of 4‐VP content on hydrodynamic radius and volume phase transition is systematically studied at different pH values. The effect of 4‐VP content on the glucose sensitivity is studied at physiological pH and temperature. The Lewis base moiety 4‐VP adjusts the working pH of the PBA‐based glucose‐responsive microgel to physiological values.

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Poly(ethylene glycol)‐Coated Fe3O4 Nanoparticles by UV‐Thiol‐Ene Addition of PEG Dithiol on Vinyl‐Functionalized Magnetite Surface
Authors: Amici Julia , Allia Paolo , Tiberto Paola , Sangermano Marco
Published: May 2011

Magnetite nanoparticles are synthesized and functionalized with vinyl groups (by silanization reaction with VTMS) and further coated with poly(ethylene glycol) dithiol under UV activation via thiol‐ene addition. TEM analysis is in a good agreement with DLS analyses and shows that by vinyl functionalization and following PEG coating it was possible to achieve nanometer‐sized particles with an average size of about 20–50 nm, well distributed and not‐aggregated. Superparamagnetic‐like behavior of coated Fe3O4 nanoparticles, which is typically looked for in biomedical applications, is ensured by the Brownian motion of the magnetic NPs in the ferrofluid. The polymeric coating does not modify the magnetic response of the magnetite nanoparticles.

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Quantification of changes in muscle from individuals with and without mitochondrial disease
Authors: Sleigh Kerry , Ball Susan , Hilton David A.
Published: May 2011

Introduction: Muscle biopsy is used in the diagnosis of mitochondrial disorders. There are limited data on the normal ranges, so interpretation of findings can be difficult. Methods: We evaluated the percentage of fibers showing mitochondrial abnormalities using Gomori trichrome staining, succinate dehydrogenase, and cytochrome oxidase histochemistry in autopsy samples taken from 45 individuals without evidence of muscle disease and biopsies from 17 patients with mitochondrial disorders. Results: In controls, mitochondrial abnormalities were rare before the fifth decade, and most had <0.1% abnormal fibers. The proportion of abnormal fibers increased with age and was higher in deltoid than quadriceps. Most patients with mitochondrial disorders had >0.5% abnormal fibers. Conclusions: Although some patients with mitochondrial disease have very few muscle fibers that show mitochondrial abnormalities, a rate of abnormality of >0.5% fibers, in the absence of a primary muscle disease this should raise the possibility of a mitochondrial disorder. Muscle Nerve, 2011
Crossed spinal soleus muscle communication demonstrated by H‐reflex conditioning
Authors: Stubbs Peter W. , Nielsen Jørgen F. , Sinkjær Thomas , Mrachacz‐Kersting Natalie
Published: May 2011

Introduction: A conditioning volley to the ipsilateral tibial nerve (iTN) inhibits contralateral soleus (cSOL) electromyographic activity at latencies of 37–41 ms. This is evidence for spinal muscular communication in opposing limbs. The aim of our study was to determine whether the cSOL H‐reflex would be inhibited in a similar manner. Methods: Thirteen subjects participated in two experiments: (1) stimuli delivered to the iTN at 85% of the maximal peak‐to‐peak M‐wave (85% M‐max) with a pre‐contracted cSOL; (2) 510 stimuli delivered at 85% M‐max to the iTN with a test volley delivered to the contralateral tibial nerve at interstimulus intervals of −6 to 100 ms. Results: Significant inhibition was observed in the cSOL H‐reflex when conditioning stimuli were delivered 3–33 ms before the test H‐reflex. Conclusions: The activity of this spinal pathway can be quantified using H‐reflex conditioning to provide a controlled model for further studies of this response. Muscle Nerve, 2011
Analysis of continuous diaphragm electromyographic signal: Results from a patient with amyotrophic lateral sclerosis
Authors: Katzberg Hans D. , Barros Daniel F. , Widrow Bernard , Cho Charles S. , So Yuen T.
Published: May 2011

Introduction: Analysis of continuous diaphragm electromyography (dEMG) has not been well studied. We describe a system of analyzing continuous dEMG using implanted electrodes.Methods: dEMG signal was acquired via two pairs of electrodes near the diaphragm motor points. Raw bursts of dEMG signal were compared to externally captured electrocardiogram (ECG) using adaptive filtering in order to remove cardiac contamination. Differential energy levels were used to identify each dEMG burst, and average amplitude and area values from both hemidiaphragms were aggregated and averaged for the duration of the recording.Results: A 64‐year‐old patient with amyotrophic lateral sclerosis underwent three serial dEMG studies every 6 months. An average of three tracings were collected per visit, and all had excellent intertest reliability (κ > 0.8). Average dEMG area correlated with forced vital capacity and mean inspiratory pressure (r2> 0.9).Conclusions: The approach described represents a comprehensive method for capturing and analyzing continuous diaphragm EMG signal. Muscle Nerve, 2011
Electrodiagnostic consultation and identification of neuromuscular conditions in persons with diabetes
Authors: Sohn Min‐Woong , Whittle Jeff , Pezzin Liliana E. , Miao Haiyan , Dillingham Timothy R.
Published: May 2011

Introduction: Although the American Association of Neuromuscular and Electrodiagnostic Medicine recommends that electrodiagnostic procedures should be performed by physicians with specialty training, these procedures are increasingly being performed by non‐specialists. Methods: We used a nationally representative sample of Medicare beneficiaries with diabetes who used electrodiagnostic services in 2006 to examine whether specialists and non‐specialists were different in the rates of identifying common neuromuscular conditions. Results: Specialists (neurologists and physiatrists) performed 62% of electrodiagnostic consultations; non‐specialist physicians and non‐physicians performed 31% and 5%, respectively. After adjusting for age, race/ethnicity, diabetes severity, and comorbidities, specialists were 1.26–9 times more likely than non‐physicians to diagnose polyneuropathy, lumbosacral radiculopathy, cervical radiculopathy, carpal tunnel syndrome, and ulnar neuropathy. Almost 80% of electrodiagnostic studies performed by specialists included electromyography testing; fewer than 13% by non‐specialists did. Conclusions: Inadequate use of electromyography and fewer specific diagnoses suggest that many non‐specialists perform insufficiently comprehensive electrodiagnostic studies. Muscle Nerve, 2011
A note on a generalization of eigenvector centrality for bipartite graphs and applications
Authors: Daugulis Peteris
Published: May 2011

Eigenvector centrality is a linear algebra based graph invariant used in various rating systems such as webpage ratings for search engines. A generalization of the eigenvector centrality invariant is defined which is motivated by the need to design rating systems for bipartite graph models of time‐sensitive and other processes. The linear algebra connection and some applications are described. © 2011 Wiley Periodicals, Inc. NETWORKS, 2012
An ETD Crank‐Nicolson method for reaction‐diffusion systems
Authors: Kleefeld B. , Khaliq A.Q.M. , Wade B.A.
Published: May 2011

A novel Exponential Time Differencing Crank‐Nicolson method is developed which is stable, second‐order convergent, and highly efficient. We prove stability and convergence for semilinear parabolic problems with smooth data. In the nonsmooth data case, we employ a positivity‐preserving initial damping scheme to recover the full rate of convergence. Numerical experiments are presented for a wide variety of examples, including chemotaxis and exotic options with transaction cost. © 2011Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2012
Superconvergence for a time‐discretization procedure for the mixed finite element approximation of miscible displacement in porous media
Authors: Cheng Aijie , Wang Kaixin , Wang Hong
Published: May 2011

A time‐stepping procedure is established and analyzed for the problem of miscible displacement in porous medium. The fluid velocity based on mixed element method is post‐processed by interpolation along Gauss lines. Error analysis shows that this procedure has a superconvergence error bound O(h) with respect to the parameter hp, which is one order higher than the conventional Galerkin or mixed finite element procedures. Compared with the results in the references, the parameter constraint conditions in this article are obviously relaxed. © 2011Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2012
Interlaboratory studies of highly permeable thin‐film composite polyamide nanofiltration membrane
Authors: Rahimpour Ahmad , Jahanshahi Mohsen , Peyravi Majid , Khalili Soodabeh
Published: May 2011

The aim of this paper is to survey interlaboratory studies of performance data to produce highly permeable thin‐film composite (TFC) polyamide nanofiltration (NF) membrane in the form of flat sheet at bench scale. TFC polyamide NF membranes were fabricated via interfacial polymerization of 1,3‐phenylenediamine and trimesoyl chloride on porous polyethersulfone (PES) membrane. The NF membranes were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and cross‐flow filtration. The AFM and SEM analyses indicated that a rough and dense film was formed on the PES support membrane. The permeability and NaCl rejection of the NF membrane prepared at the presence of camphor sulfonic acid as pH regulator and triethylamine as accelerator in the aqueous solution were 21 l m−2 h−1 and 70%, respectively. In order to estimate the repeatability and reproducibility standard deviations, the development of an interlaboratory study was conducted by measurements of permeation flux and salt rejection of the synthesized membranes. Repeatability standard deviation of the permeation flux data for the membrane based on optimum formulation was 1.99, and reproducibility standard deviation was 3.55. Also based on this trend, repeatability standard deviation of the salt rejection data was 1.57, and reproducibility standard deviation was 4.11. The American Society for Testing and Materials standard E691‐05 was used for data validation of the repeatability and reproducibility standard deviations and consistency statistics. Copyright © 2011 John Wiley & Sons, Ltd.
Utilizing Medicare claims data for real‐time drug safety evaluations: is it feasible?,
Authors: Hartzema Abraham G. , Racoosin Judith A. , MaCurdy Thomas E. , Gibbs Jonathan M. , Kelman Jeffrey A.
Published: May 2011

Purpose

The Centers for Medicare & Medicaid Services claims comprise an administrative database of beneficiary‐specific clinical information. This study evaluates the impacts of (i) claim information updates (claims adjudication) and (ii) delay in claim processing (claims delay) on real‐time evaluation of health service and drug safety signals using the Medicare database.

Methods

Using Medicare claims data accumulated through May 2009 on health services rendered in 2006 and drugs dispensed in 2007, this study measures the frequency with which clinical information changes in the database as a result of (i) claims adjudication and (ii) claims delay.

Results

Over 85% of health services claims were processed within 8 weeks after the date of service, and 72% of drug claims were processed within 3 months after the dispense date. Clinical information changed for no more than 3% of unique claim groups in inpatient hospital, outpatient institutional, physician's office, and prescription drug Medicare claim settings.

Conclusions

Claims delay is consistent across time and is minimal. Claims adjudication does not substantially impact the content of clinical information in the Medicare claims database. Therefore, the Medicare claims database provides consistent information regarding health services and prescription drugs in a manner that is prompt enough to facilitate medical product safety evaluations in real time. Copyright © 2011 John Wiley & Sons, Ltd.
Systematic review of peptic ulcer disease incidence rates: do studies without validation provide reliable estimates?
Authors: Lin Kueiyu Joshua , García Rodríguez Luis A. , Hernández‐Díaz Sonia
Published: May 2011

Purpose

Incidence rate (IR) estimates for peptic ulcer disease (PUD) vary widely among studies. We conducted a systematic review to quantify and examine the discrepancies.

Methods

Of 4780 articles identified from PubMed and EMBASE databases, 31 published in the last three decades that had reported IRs of PUD in the general population were included. Random effects meta‐analysis and meta‐regression were performed to calculate pooled estimates and to identify sources of heterogeneity.

Results

The pooled IR estimate per 1000 person‐years was 0.90 (95% confidence interval: 0.78–1.04) for uncomplicated PUD, 0.57 (0.49–0.65) for peptic ulcer bleeding, 0.10 (0.08–0.13) for gastrointestinal perforations, and 3.18 (2.05–4.92) for nonspecific PUD. Within specific outcomes definitions, IR estimates were significantly lower in studies with restriction to hospitalized cases, case validation, and case ascertainment directly from hospital or clinical sources versus computerized health care databases. Younger age, female sex, and later calendar time were also associated with lower PUD incidence.

Conclusions

We found that the IR of uncomplicated PUD was in the order of one case per 1000 person‐years in the general population, and that the IR of peptic ulcer complications was around 0.7 cases per 1000 person‐years. Comparisons of IR estimates among studies need to take into account disease definition and other study characteristics, particularly whether outcome validation was performed in computerized claims. The use of claims to identify PUD cases might overestimate the IR by around 45%. Copyright © 2011 John Wiley & Sons, Ltd.
Functional copolymer/organo‐montmorillonite nanoarchitectures. IX. Synthesis and nanostructure–morphology–thermal behaviour relationships of poly[(maleic anhydride)‐alt‐(acrylic acid)]/organo‐ montmorillonite nanocomposites
Authors: Rzayev Zakir MO , Şenol Burcu , Denkbaş Amir B
Published: May 2011

Functional copolymer/clay hybrids were synthesized by radical‐initiated interlamellar copolymerization of maleic anhydride/maleic acid and acrylic acid with 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride as a water‐soluble ionizable radical initiator in the presence of reactive (octadecylamine‐montmorillonite (ODA‐MMT)) and non‐reactive (dimethyldodecylammonium‐montmorillonite) organoclays at 60 °C in aqueous medium under nitrogen atmosphere. The monomers were dissolved in aqueous medium, and the two types of clay particles used were easily dissolved and dispersed partially swollen, respectively, in deionized water. Structure, thermal behaviour and morphology of the synthesized nanocomposites were investigated using Fourier transform infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and scanning and transmission electron microscopy. It is demonstrated that intercalative copolymerization proceeds via ion exchange between organoclays and carboxylic groups of monomers/polymers, which essentially improves interfacial interactions of polymer matrix and clay layers through strong hydrogen bonding. In the case of intercalative copolymerization in the presence of ODA‐MMT clay, a similar improvement is provided by in situ hydrogen bonding and amidolysis of carboxylic/anhydride groups from copolymer chains with primary amine groups of ODA‐MMT. The nanocomposites exhibit higher degree of intercalation/exfoliation of copolymer chains, improved thermal properties and fine dispersed morphology. Copyright © 2011 Society of Chemical Industry
Synthesis and photophysical properties of soluble low‐bandgap thienothiophene polymers with various alkyl side‐chain lengths
Authors: Bae Woo Jin , Scilla Christopher , Duzhko Volodimyr V. , Ho Jo Won , Coughlin E. Bryan
Published: May 2011

We report the facile synthesis and characterization of a class of thienothiophene polymers with various lengths of alkyl side chains. A series of 2‐alkylthieno[3,4‐b]thiophene monomers (Ttx) have been synthesized in a two‐step protocol in an overall yield of 28–37%. Poly(2‐alkylthieno[3,4‐b]thiophenes) (PTtx, alkyl: pentyl, hexyl, heptyl, octyl, and tridecyl) were synthesized by oxidative polymerization with FeCl3 or via Grignard metathesis (GRIM) polymerization methods. The polymers are readily soluble in common organic solvents. The polymers synthesized by GRIM polymerization method (PTtx‐G) have narrower molecular weight distribution (Đ) with lower molecular weight (Mn) than those synthesized by oxidative polymerization (PTtx‐O). The band structures of the polymers with various lengths of alkyl side chains were investigated by UV–vis spectroscopy, cyclic voltammetry, and ultraviolet photoelectron spectroscopy. These low‐bandgap polymers are good candidates for organic transistors, organic light‐emitting diodes, and organic photovoltaic cells. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Ethylene polymerization using novel titanium catalytic precursors bearing N,N‐dialkylcarbamato ligands
Authors: Forte Claudia , Hayatifar Mohammad , Pampaloni Guido , Galletti Anna Maria Raspolli , Renili Filippo , Zacchini Stefano
Published: May 2011

Polymerization catalysts based on N,N‐dialkylcarbamato complexes of titanium(IV) appear particularly interesting, because these novel catalytic precursors are rather cheap and easy to synthesize and handle. This contribution reports ethylene polymerization behavior of titanium(IV) complexes of general formula Ti(O2CNR2)4 R = Me (I) and Et (II) and TiCl2(O2CNMe2)2 (III). These precursors in conjunction with methylaluminoxane resulted active catalysts for the polymerization of ethylene, affording high‐density polyethylene with limited branch content. The influence of the polymerization parameters was studied with particular reference to the type of catalyst components, solvent, temperature, monomer concentration, and Al/Ti ratio. The nature of the solvent appears crucial for catalytic performances: when toluene was replaced by chlorobenzene, a significant increase of the productivity was ascertained. The obtained polymers were characterized by DSC, size exclusion chromatography, FTIR, and NMR techniques. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Influence of the stirring speed and CaCl2 concentration on the nano‐object morphologies obtained via RAFT‐mediated aqueous emulsion polymerization in the presence of a water‐soluble macroRAFT agent
Authors: Boissé Stéphanie , Rieger Jutta , Pembouong Gaëlle , Beaunier Patricia , Charleux Bernadette
Published: May 2011

Aqueous emulsion polymerizations of styrene were performed in the presence of a macromolecular reversible addition‐fragmentation chain transfer (RAFT) agent (macroRAFT) composed of acrylic acid (AA) and poly(ethylene oxide) methyl ether acrylate (PEOA), end‐capped by a reactive dodecyl trithiocarbonate group (P(AA‐co‐PEOA)‐TTC). The influence of the stirring speed or the presence of different amounts of a divalent salt, CaCl2, were investigated in this polymerization‐induced self‐assembly process, in which spherical and nonspherical nano‐objects were formed upon the synthesis of amphiphilic diblock copolymers in situ. It appeared that the addition of CaCl2 led to the controlled formation of different nano‐objects such as spheres, fibers or vesicles, whereas an appropriate stirring speed was required for the formation of nanofibers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and electroluminescence properties of white‐light single polyfluorenes with high‐molecular weight by click reaction
Authors: Lo Chih‐Nan , Hsu Chain‐Shu
Published: May 2011

We reported a new way to synthesize single‐chain white light‐emitting polyfluorene (WPF) with an increased molecular weight using azide‐alkyne click reaction. Four basic polymers with specific end‐capping, which exhibited high‐glass transition temperatures (Tg > 100 °C) and excellent thermal stability, were used as foundations of the WPF's synthesis; a blue‐light polymer (PFB2) end‐capped with azide groups can easily react with acetylene end‐capped polymers (PFB1, PFG1, and PFR1, which are emitting blue‐, green‐ and red‐light, respectively) to form triazole‐ring linkages in polar solvents such as N,N‐dimethylforamide/toluene co‐solvent at moderate temperature of 100 °C, even without metal‐catalyst. Several WPFs that consist of these four basic polymers in certain ratios were derived, and the polymer light‐emitting diode device based on the high‐molecular weight WPF was achieved and demonstrated a maximum brightness of 7551 cd/m2 (at 12.5 V) and a maximum yield of 5.5 cd/A with Commission Internationale de l'Eclairage coordinates of (0.30, 0.33) using fine‐tuned WPF5 as emitting material. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
High‐Rate Deposition of Electrochromic Organotungsten Oxide Thin Films for Flexible Electrochromic Devices by Atmospheric Pressure Plasma Jet: The Effect of Substrate Distance
Authors: Lin Yung‐Sen , Wu Siang‐Syuan , Tsai Tsung‐Hsien
Published: May 2011

High‐rate deposition of electrochromic organotungsten oxide (WOxCy) films onto flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates by atmospheric pressure‐plasma enhanced chemical vapor deposition (AP‐PECVD) with atmospheric pressure plasma jet (APPJ) under various substrate distances is investigated. A precursor (tungsten carbonyl, W(CO)6, TC) vapor, carried by argon gas, is injected into air plasma torch for the synthesis of WOxCy films. Uniform light modulation up to 1 cm wide on PET/ITO/WOxCy is produced, while the moving PET/ITO substrate is exposed to a 0.3 cm diameter plasma torch at room temperature (≈23 °C) and atmospheric pressure. The porous APPJ‐synthesized WOxCy films result in fast responses using potential steps for coloration of 11.5 s at −1V and bleaching of 7.2 s at +1V, respectively. APPJ‐synthesized WOxCy films offer noteworthy electrochromic performance in light modulation with up to 73.0% of transmittance variation, optical density change of 0.72 and coloration efficiency of 67.7 cm2 · C−1 at a wavelength of 800 nm.

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Analysis of 170 cases of congenital TB reported in the literature between 1946 and 2009
Authors: Peng Wansheng , Yang Juan , Liu Enmei
Published: May 2011

Introduction

Congenital tuberculosis is a rare disease. The mortality is very high. Through a review of our own cases and the world literature, we describe clinical manifestations, treatment, and prognosis of this disease.

Methods

A total of 170 subjects with congenital tuberculosis that 6 cases identified by the authors and 164 cases identified in other case series were included in this study. All patients were diagnosed according to Cantwell's criteria. The data were analyzed using SPSS, version 17.0 spss.

Results

There were 70 premature babies among the 170 infants with congenital tuberculosis. The average onset age was 20 days. The mothers of 162 patients were diagnosed as having active tuberculosis during pregnancy or after parturition. Nonspecific signs and symptoms were found in these 170 cases, such as fever, respiratory distress, and hepatosplenomegaly, etc. Abnormal chest radiographs were found in 133 infants, of whom 83 cases showed miliary tuberculosis and multiple pulmonary nodules. Sixty‐eight infants died from among the 169 cases. The mortality dropped to 21.7% after treatment with anti‐tuberculosis medication. The blood leukocyte count (P < 0.001), anti‐tuberculosis treatment (P < 0.001), age of onset (P = 0.004), and presence of intracranial lesions (P < 0.001) affected the prognosis of congenital tuberculosis.

Conclusions

The majority of infants with congenital tuberculosis onset within 2–3 weeks after delivery had no specific manifestations. Anti‐tuberculosis medication could reduce the mortality. The age of onset, presence of intracranial lesions, anti‐tuberculosis treatment, specific image performances and leukocyte count were related to the prognosis of congenital tuberculosis. Pediatr Pulmonol. 2011; 46: 1215–1224. © 2011 Wiley Periodicals, Inc.
Modeling the Microstructure of Energetic Materials with Realistic Constituent Morphology
Authors: Jackson Thomas L. , Hooks Daniel E. , Buckmaster John
Published: May 2011

In this article, we present a strategy for packing realistic crystals, critical for mesoscale simulations, and predictions. The current packing code uses a dynamic algorithm, with crystal shapes represented by level sets, to create appropriate packs of the microstructure for an energetic material. Crystal shapes include the nitramines HMX, RDX, PETN, and CL20. Two series of packs are considered: a bidisperse pack with size ratio 1 : 0.3 and a polydisperse pack. We also construct equivalent packs of spheres for comparison purposes. Higher‐order statistics are computed and compared. We show that the second‐order statistics are essentially independent of particle shape when the packing fraction is held constant. The second‐order statistics do, however, depend on the polydispersity.
Explosives Based on Diaminourea
Authors: Fischer Niko , Klapötke Thomas M. , Stierstorfer Jörg
Published: May 2011

Diaminourea (DAU, 1) is synthesized by the reaction of dimethylcarbonate with hydrazine hydrate. DAU was protonated using nitric as well as perchloric acid yielding diaminouronium nitrate (2), diaminouronium dinitrate monohydrate (3) and diaminouronium perchlorate (4). The bis‐perchlorate salt could not be isolated due to its high hygroscopicity. Explosives 2–4 were fully characterized using X‐ray diffraction, NMR and vibrational spectroscopy, mass spectrometry and elemental analysis. The thermal properties were determined by differential scanning calorimetry (DSC). The sensitivities towards impact (2: 9 J, 3: >40 J, 4: 2 J), friction (2: 288 N, 3: >360 N, 4: 5 N) and electrical discharge (2: 0.60 J, 3: 0.50 J, 4: 0.30 J) were investigated using Bundesanstalt für Materialforschung (BAM) methods and a small scale electrostatic discharge device. The detonation parameters of 2 and 3 were computed using the EXPLO5.04 code with the X‐ray densities as well as calculated (CBS‐4 M) energies of formation as input values.
Investigation of long wavelength green InGaN lasers on c‐plane GaN up to 529 nm continuous wave operation
Authors: Müller Jens , Strauß Uwe , Lermer Teresa , Brüderl Georg , Eichler Christoph , Avramescu Adrian , Lutgen Stephan
Published: May 2011

We present analysis of the experimentally determined gain coefficients g0 for green InGaN lasers with pulsed wavelengths from 495 to 526 nm. Variable facet coating as well as variable cavity length method are used to deduce the dependency of g0 on wavelength. From the experimental data we found that better laser performance at shorter wavelengths correlates with higher material gain. Therefore, lasers at 504 nm reach wall plug efficiencies (WPE) up to 5.3% at 50 mW cw output power, while lasers with 525 and 529 nm show a WPE up to 3 and 2.3%, respectively. The WPE for longer wavelengths is limited due to thermal rollover in cw operation.
Selected optical properties of core/shell ZnMnTe/ZnO nanowire structures
Authors: Gas Katarzyna , Janik Elżbieta , Zaleszczyk Wojciech , Dynowska Elżbieta , Kutrowski Mirosław , Kamińska Agnieszka , Morhange Jean‐François , Wachnicki Łukasz , Wojciechowski Tomasz , Hołyst Robert , Godlewski Marek , Guziewicz Elżbieta , Wojtowicz Tomasz , Szuszkiewicz Wojciech
Published: May 2011

We report here on selected optical properties of core/shell Zn1−xMnxTe/ZnO nanowires (NWs). The Zn1−xMnxTe cores of the investigated structures (containing from 3.5 to 7% of Mn) were grown by the MBE technique using gold‐catalyzed vapor–liquid–solid mechanism. Polycrystalline ZnO shells coating Zn1−xMnxTe NWs were overgrown by the atomic layer deposition (ALD) method. Core/shell NWs were then examined by scanning electron microscopy (SEM), X‐ray diffraction (XRD), Raman scattering, and photoluminescence (PL) measurements. The lines characteristic of the ZnO band edge emission and the intra‐Mn2+ transition were observed in the PL spectra. Modification of the Raman spectra of as‐grown Zn1−xMnxTe samples induced by the ZnO shell is demonstrated and discussed.
Initial stages of growth of iron on silicon for spin injection through Schottky barrier
Authors: Dash Saroj Prasad , Carstanjen Heinz Dieter
Published: May 2011

The characterization of ferromagnet‐semiconductor interfaces with monolayer (ML) depth resolution is an important issue in the development of spin injection devices. In this article, highly resolved depth distributions of Fe have been measured during the initial stages of growth of Fe on Si (100) at room temperature by in situ high‐resolution Rutherford backscattering spectrometry. Extensive in‐diffusion of Fe has been observed even for the coverage of 0.0325 ML of Fe. At this coverage the Si crystal structure is apparently still conserved. Every second Si layer is depleted of Fe, thus giving rise to compositional oscillations of Fe. At higher coverages strong interdiffusion occurs resulting in the formation of silicides at the interface. Even at 9.2 ML of Fe coverage, no pure Fe layers were observed.