bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuropathology of Alzheimer's Disease
Authors: Perl Daniel P.
Published: January 2010

Alois Alzheimer first pointed out that the disease which would later bear his name has a distinct and recognizable neuropathological substrate. Since then, much has been added to our understanding of the pathological lesions associated with the condition. The 2 primary cardinal lesions associated with Alzheimer's disease are the neurofibrillary tangle and the senile plaque. The neurofibrillary tangle consists of abnormal accumulations of abnormally phosphorylated tau within the perikaryal cytoplasm of certain neurons. The senile plaque consists of a central core of beta‐amyloid, a 4‐kD peptide, surrounded by abnormally configured neuronal processes or neurites. Other neuropathological lesions are encountered in cases of Alzheimer's disease, but the disease is defined and recognized by these 2 cardinal lesions. Other lesions include poorly understood changes such as granulovacuolar degeneration and eosinophilic rodlike bodies (Hirano bodies). The loss of synaptic components is a change that clearly has a significant impact on cognitive function and represents another important morphological alteration. It is important to recognize that distinguishing between Alzheimer's disease, especially in its early stages, and normal aging may be very difficult, particularly if one is examining the brains of patients who died at an advanced old age. It is also noted that instances of pure forms of Alzheimer's disease, in the absence of other coexistent brain disease processes, such as infarctions or Parkinson's disease–related lesions, are relatively uncommon, and this must be taken into account by researchers who employ postmortem brain tissues for research. Mt Sinai J Med 77:32&–42, 2010. © 2010 Mount Sinai School of Medicine
Amyloid‐β Oligomers: Possible Roles as Key Neurotoxins in Alzheimer's Disease
Authors: Lublin Alex L. , Gandy Sam
Published: January 2010

Alzheimer's disease is the most common form of senile dementia. Although the amyloid‐β peptide was identified in 1984 as the major constituent of the senile plaques that characterize the disease, accumulating evidence indicates that the plaque density does not correspond well to the concurrent disease state. In order to resolve this disconnect, a number of recent studies have shifted away from the senile plaque and classical fibrillar forms of amyloid toward a less well structured species as the proximate neurotoxic factor underlying cognitive failure in Alzheimer's disease: soluble amyloid‐β peptide oligomer (also known as the amyloid‐β peptide–derived diffusible ligand). Paradoxically, several studies in the last 2 years have shown that picomolar levels of amyloid‐β peptide have neutral activity or perhaps even an essential role in learning and memory. Here we highlight some of the key observations underlying the growing focus on the amyloid‐β peptide oligomer. Mt Sinai J Med 77:43&–49, 2010. © 2010 Mount Sinai School of Medicine
Relationship Between Tau Pathology and Neuroinflammation in Alzheimer's Disease
Authors: Metcalfe Maria Jose , Figueiredo‐Pereira Maria E.
Published: January 2010

Alzheimer's disease is a chronic, age‐related neurodegenerative disorder. Neurofibrillary tangles are among the pathological hallmarks of Alzheimer's disease. Neurofibrillary tangles consist of abnormal protein fibers known as paired helical filaments. The accumulation of paired helical filaments is one of the most characteristic cellular changes in Alzheimer's disease. Tau protein, a microtubule‐associated protein, is the major component of paired helical filaments. Tau in paired helical filaments is hyperphosphorylated, truncated, and aggregated. What triggers the formation of paired helical filaments is not known, but neuroinflammation could play a role. Neuroinflammation is an active process detectable in the earliest stages of Alzheimer's disease. The neuronal toxicity associated with inflammation makes it a potential risk factor in the pathogenesis of Alzheimer's disease. Determining the sequence of events that lead to this devastating disease has become one of the most important goals for the prevention and treatment of Alzheimer's disease. In this review, we focus on the pathological properties of tau thought to play a role in neurofibrillary tangle formation and summarize how central nervous system inflammation might be a critical contributor to the pathology of Alzheimer's disease. A better understanding of the mechanisms that cause neurofibrillary tangle formation is of clinical importance for developing therapeutic strategies to prevent and treat Alzheimer's disease. One of the major challenges facing us is singling out neuroinflammation as a therapeutic target for the prevention of Alzheimer's disease neurodegeneration. The challenge is developing therapeutic strategies that prevent neurotoxicity linked to inflammation without compromising its neuroprotective role. Mt Sinai J Med 77:50&–58, 2010. © 2010 Mount Sinai School of Medicine
First Season of 2009 H1N1 Influenza
Authors: Swedish Kristin A. , Conenello Gina , Factor Stephanie H.
Published: January 2010

The 2009 H1N1 influenza virus is responsible for the first influenza pandemic of the 21st century. Within 5 months after its emergence in Mexico, it had affected more than 290,000 patients and caused at least 3486 deaths on 6 continents. This report provides information about influenza viruses, previous pandemics, and the virology, clinical features, and epidemiology of 2009 H1N1 influenza in order to elucidate the current pandemic and outline the questions that remain. Mt Sinai J Med 77:103&–113, 2010. © 2010 Mount Sinai School of Medicine
Current Treatment and Recent Clinical Research in Alzheimer's Disease
Authors: Neugroschl Judith , Sano Mary
Published: January 2010

The transition from either epidemiological observation or the bench to rigorously tested clinical trials in patients with Alzheimer's disease is crucial in understanding which treatments are beneficial to patients. The amyloid hypothesis has undergone scrutiny recently, as many trials aimed at reducing amyloid and plaque have been completed or are in the testing phase. Examples include modulation of the secretases involved in beta amyloid formation, anti‐aggregation agents, and immunotherapeutic trials. Other therapies targeting hyperphosphorylated tau and novel targets such as enhancement of mitochondrial function, serotonin receptors, receptor for advanced glycation end products, and nerve growth factor, as well as other strategies, are discussed. A brief review of the current Food and Drug Administration–approved treatments is included. Mt Sinai J Med 77:3&–16, 2010. © 2010 Mount Sinai School of Medicine
Single‐voxel MRS with prospective motion correction and retrospective frequency correction
Authors: Zaitsev M. , Speck O. , Hennig J. , Büchert M.
Published: January 2010

Subject motion during MRS investigations is a factor limiting the quality and the diagnostic value of the spectra. The possibility of using external motion tracking data to correct for artefacts in MR imaging has been demonstrated previously. In this paper the utility of prospective motion correction for single‐voxel proton MRS is investigated. The object motion data are used in real time to update the position of the spectroscopy voxel during the acquisition prior to every sequence repetition cycle. It is not, however, sufficient to update the voxel position alone due to shim changes accompanying subject motion. Adverse effects of frequency shifts induced by subject motion are effectively suppressed by the interleaved reference scan method. Copyright © 2010 John Wiley & Sons, Ltd.
Coping strategies in daily occupations 3 months after a severe or major hand injury
Authors: Cederlund Ragnhild , Thorén‐Jönsson Anna‐Lisa , Dahlin Lars B.
Published: January 2010

Coping strategies used in performing daily occupations 3 months after a severe or major hand injury were explored. A semi‐structured interview was performed with 13 participants with hand injuries based on Hand Injury Severity Scoring System and analysed using content analysis. Six groups of strategies were identified: ‘Changing performance of daily occupations’, ‘Actively processing trauma experience’, ‘Changing occupational patterns’, ‘Receiving assistance’, ‘Using emotional strategies’ and ‘Keeping up a social network’. The problem‐ and emotional‐solving strategies identified in this study can be used to support other patients early in rehabilitation. Patients with few coping strategies should be recognized. Information and practical handouts to patients, therapists and relatives should stimulate and help patients with hand problems enabling in meaningful occupations and preventing unnecessary stress. Furthermore, social support should be encouraged and family should be actively involved in rehabilitation. To insure trustworthiness, member checks were used on four randomly selected participants, but could possibly be used with all participants. Further research is needed in a longitudinal study to explore which coping strategies or adaptation patients use to perform daily occupations at a later stage. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluation of different amine‐functionalized polyethylenes as compatibilizers for polyethylene film nanocomposites
Authors: Sánchez‐Valdes Saúl , Méndez‐Nonell Juan , Medellín‐Rodríguez Francisco J , Ramírez‐Vargas Eduardo , Martínez‐Colunga Juan G , de Valle Luis F Ramos , Mondragón‐Chaparro Margarita , López‐Quintanilla Maria L , García‐Salazar Maria L
Published: January 2010

The compatibilization effects provided by different amine‐functionalized polyethylenes (PEs) versus those provided by a maleated polyethylene (PEgMA), for forming PE‐based film nanocomposites, were studied. Amine‐functionalized PEs were prepared by reaction of PEgMA with two primary amines, 2‐aminoethanol (EA) and 1,12‐aminododecane (D12), and a tertiary amine, 2‐[2‐(dimethylamino)ethoxy]ethanol (DMAE), in the melt to form the corresponding PEgEA, PEgD12 and PEgDMAE. Nanocomposites were prepared by melt mixing in a twin‐screw extruder PE and these three functionalized compatibilizers with a modified montmorillonite clay. The purpose of the current work was to determine the effect of the various amine‐functionalized PEs on the degree of exfoliation and optical properties of PE–clay nanocomposites in order to obtain nanocomposite films for greenhouse cover applications. Fourier transform infrared analysis confirmed the formation of the amine‐modified PE compatibilizers. Structural, morphological, mechanical, rheological and optical properties of film samples were used to characterize the nanocomposites. All the amine‐modified PE‐compatibilized nanocomposites had better clay exfoliation compared to uncompatibilized PE composites. Results showed that PEgDMAE formed highly exfoliated morphology and a favorable balance between mechanical (stiffness and ductility), optical and thermal insulating film properties even at higher clay contents. It was determined that nanocomposites with greater exfoliated structure showed better optical and thermal insulating film properties. PEgEA and PEgD12 compatibilizers did not provide a better interaction for exfoliation of the organoclay than the PEgMA material. The PEgDMAE compatibilizer led to a highly exfoliated morphology and a favorable balance between mechanical, optical and thermal insulating film properties even at higher clay contents. The PEgDMAE film nanocomposites could be used ideally for greenhouse cover applications. Copyright © 2010 Society of Chemical Industry
Maximizing the sensitivity and reliability of peptide identification in large‐scale proteomic experiments by harnessing multiple search engines
Authors: Yu Wen , Taylor J. Alex , Davis Michael T. , Bonilla Leo E. , Lee Kimberly A. , Auger Paul L. , Farnsworth Chris C. , Welcher Andrew A. , Patterson Scott D.
Published: January 2010

Despite recent advances in qualitative proteomics, the automatic identification of peptides with optimal sensitivity and accuracy remains a difficult goal. To address this deficiency, a novel algorithm, Multiple Search Engines, Normalization and Consensus is described. The method employs six search engines and a re‐scoring engine to search MS/MS spectra against protein and decoy sequences. After the peptide hits from each engine are normalized to error rates estimated from the decoy hits, peptide assignments are then deduced using a minimum consensus model. These assignments are produced in a series of progressively relaxed false‐discovery rates, thus enabling a comprehensive interpretation of the data set. Additionally, the estimated false‐discovery rate was found to have good concordance with the observed false‐positive rate calculated from known identities. Benchmarking against standard proteins data sets (ISBv1, sPRG2006) and their published analysis, demonstrated that the Multiple Search Engines, Normalization and Consensus algorithm consistently achieved significantly higher sensitivity in peptide identifications, which led to increased or more robust protein identifications in all data sets compared with prior methods. The sensitivity and the false‐positive rate of peptide identification exhibit an inverse‐proportional and linear relationship with the number of participating search engines.
Network generation enhances interpretation of proteomic data from induced apoptosis
Authors: Deighton Ruth F. , Kerr Lorraine E. , Short Duncan M. , Allerhand Mike , Whittle Ian R. , McCulloch James
Published: January 2010

Thirteen proteins (identified with 2‐D gels and MALDI‐TOF MS) are significantly altered during staurosporine‐induced apoptosis in SH‐SY5Y cells. To gain further insight into the integrated cellular response to apoptosis, we have investigated whether a network can be generated of direct and indirect interactions between these 13 proteins. A network that contains 12 out of the 13 proteins was generated using Ingenuity Pathway Analysis (IPA) and this network is dominated (89%) by direct protein−protein interactions. This network scored 34 with IPA. Bootstrapping 1000 random lists of 13 proteins suggested that the frequency of this score occurring by chance was 1 in 500. We examined whether subsets of proteins such as HSPs, which were elevated after staurosporine, had a disproportionate impact on the network generated. There was no evidence that any subset of 8 from the 13 proteins contributed disproportionately to the network. Network generation, using IPA, identified common features (such as endoplasmic reticular stress protein interactions) in apoptotic studies from different laboratories. The generation of protein interaction networks clearly enhances the interpretation of proteomic data, but only when interpreted cautiously, particularly in respect of statistical analyses.
A guided tour of the Trans‐Proteomic Pipeline
Authors: Deutsch Eric W. , Mendoza Luis , Shteynberg David , Farrah Terry , Lam Henry , Tasman Natalie , Sun Zhi , Nilsson Erik , Pratt Brian , Prazen Bryan , Eng Jimmy K. , Martin Daniel B. , Nesvizhskii Alexey I. , Aebersold Ruedi
Published: January 2010

The Trans‐Proteomic Pipeline (TPP) is a suite of software tools for the analysis of MS/MS data sets. The tools encompass most of the steps in a proteomic data analysis workflow in a single, integrated software system. Specifically, the TPP supports all steps from spectrometer output file conversion to protein‐level statistical validation, including quantification by stable isotope ratios. We describe here the full workflow of the TPP and the tools therein, along with an example on a sample data set, demonstrating that the setup and use of the tools are straightforward and well supported and do not require specialized informatic resources or knowledge.
Photoinduced acyl transfer
Authors: Débieux Jean‐Luc , Bochet Christian G.
Published: January 2010

The acylation reaction occupies a central role in biochemistry and organic synthesis. On the one hand, it is by this very reaction that amino acids successively assemble to form peptides and proteins, and on the other hand it is a major synthetic method encompassing esterification, amidation, Friedel–Crafts reaction and many other processes routinely used both at the laboratory and the industrial scale. Photochemical activation is always an attractive alternative, because it is relatively mild (provided innocuous wavelengths are used), and no additional substance is added; thus no separation of the activator is necessary at the end of the process. In this paper, we briefly survey the most widely used methods of photoinduced acylations, and our own contribution to the field. Copyright © 2010 John Wiley & Sons, Ltd.
Density functional study for the polymerization of ethylene monomer using a new nickel catalyst
Authors: Ramos Javier , Cruz Víctor L. , Martínez‐Salazar Javier , Brasse Mikael , Palma Pilar , Campora Juan
Published: January 2010

The present computational study was designed to study the polymerization of ethylene catalyzed by a new Ni‐based PymNox organometallic compound. Recently, we have synthesized and tested the behavior of this type of catalyst in olefin polymerization. It has been experimentally observed that the unsubstituted catalyst Ni2 (aldimino PymNox catalyst) is less active than the methyl substituted Ni1 (acetaldimino PymNox catalyst) analogue. The reactivity of both catalysts was examined using density functional theory (DFT) models. Our results indicate that the methyl substituted Ni1 introduces some additional steric hindrance that probably renders a more suitable catalyst conformation for the monomer incorporation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1160–1165, 2010
SET‐LRP of acrylates in air
Authors: Fleischmann Sven , Rosen Brad M. , Percec Virgil
Published: January 2010

Single Electron Transfer‐Living Radical Polymerization (SET‐LRP) represents a robust and versatile method for the rapid synthesis of macromolecules with well defined topology. In SET‐LRP, certain combinations of solvents and ligands facilitate the disproportionation of in situ generated Cu(I) species into “nascent” Cu(0) and Cu(II) species. A combination of heterogeneous and “nascent” Cu(0) activation yields polymers with very high chain end functionality. Under suitable conditions the tolerance toward oxygen must be increased since Cu(0), the activator in SET‐LRP, acts as an oxygen scavenger in all inert gas purification systems. Here we demonstrate that SET‐LRP of methyl acrylate can be conducted in the presence of air. The addition of a small amount of reducing agent hydrazine hydrate to the reaction mixture reduces Cu2O generated by the oxidation of Cu(0) with air, regenerating Cu(0) and allowing for the synthesis of polymers with predictable molecular weight and perfect retention of chain end functionality. The kinetics plots obtained under these conditions were identical to these generated by degassed samples. High conversions were achieved within a very short reaction time. In these SET‐LRP experiments, the reagents were not deoxygenated or subjected to standard degassing procedures such as freeze‐pump‐thaw or nitrogen sparging. This simple SET‐LRP procedure provides an efficient and economical approach to the synthesis of functional macromolecules. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1190–1196, 2010
Bio‐safe synthesis of linear and branched PLLA
Authors: Målberg Sofia , Basalp Dildare , Finne‐Wistrand Anna , Albertsson Ann‐Christine
Published: January 2010

The catalytic activities of Bi(III) acetate (Bi(OAc)3) and of creatinine towards the ring‐opening polymerization of L‐lactide have been compared with those of a stannous (II) ethylhexanoate ((SnOct)2)‐based system and with those of a system catalyzed by enzymes. All four were suitable catalysts for the synthesis of high and moderate molecular weight poly(L‐lactide)s and the differences in reactivity and efficiency have been studied. Linear and branched poly(L‐lactide)s were synthesized using these bio‐safe initiators together with ethylene glycol, pentaerythritol, and myoinositol as coinitiators. The polymerizations were performed in bulk at 120 and 140 °C and different reactivities and molecular weights were achieved by adding different amounts of coinitiators. A molecular weight of 105,900 g/mol was achieved with 99% conversion in 5 h at 120 °C with a Bi(OAc)3‐based system. This system was comparable to Sn(Oct)2 at 140 °C. The reactivity of creatinine is lower than that of Bi(OAc)3 but higher compared with enzymes lipase PS (Pseudomonas fluorescens). A ratio of Sn(Oct)2Mo/Io 10,000:1 was needed to achieve a polymer with a reasonable low amount of tin residue in the precipitated polymer, and a system catalyzed by creatinine at 140 °C has a higher conversion rate than such a system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1214–1219, 2010
Poly(n‐alkylsilsesquioxane)s: Synthesis, characterization, and modification with poly(dimethylsiloxane)
Authors: Prado Luís A. S. A. De , Torriani Iris L. , Yoshida Inez V. P.
Published: January 2010

Self‐supported translucent films constituted of poly(n‐octylsilsesquioxane) or poly(n‐dodecylsilsesquioxane) were obtained from the hydrolysis and condensation of n‐octyltriethoxysilane (OTES) or n‐dodecyltriethoxysilane (DTES), respectively. Dense films were obtained in the absence of organic solvents, with dibutyltin diacetate as catalyst. These films exhibited good optical transparency and thermal stability. The incorporation of oligomeric dimethylsiloxane units (DMe,Me) in these materials, derived from silanol‐terminated poly(dimethylsiloxane) (PDMS) or 1,1,3,3‐tetramethyl‐1,3‐diethoxydisiloxane (TMDES), was carried out during the hydrolysis and condensation of OTES and DTES and was confirmed by solid‐state 29Si NMR. Poly(n‐octylsilsesquioxane) showed a glass‐transition temperature at −65 °C, due to the increase in the free volume, promoted by the bulky n‐octyl groups. The differential scanning calorimetric (DSC) curves of the polymer derived from DTES were characterized by first‐order transitions at temperatures ranging from −15.8 to −0.7 °C. Further studies of these networks by low‐temperature XRD evidenced narrowing of the diffraction halos suggesting a partial order–disorder transition for these materials at lower temperatures. Good thermal stability up to 350 °C and the solvent‐free production process make these polymers potential candidates for the development of self‐supported hydrophobic protective coatings. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1220–1229, 2010
Synthesis and solution behavior of comb‐like terpolymers with poly(ethylene oxide) macromonomer
Authors: Zhong Chuanrong , Jiang Liufeng , Peng Xiuhua
Published: January 2010

A novel macromonomer: p‐vinylbenzyl‐terminated octylphenoxy poly(ethylene oxide) (polymerization number: 18) (VBPEO) was synthesized. The comb‐like acrylamide‐based terpolymers (PVEA) were synthesized by aqueous free‐radical copolymerization technique using acrylamide (AM), VBPEO and sodium 2‐acrylamido‐2‐methylpropane sulphonate (NaAMPS). The macromonomer and PVEA polymer were characterized with Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H NMR). The polymers exhibited self‐assembly behavior in water and the brine solutions. The polymers could be employed in the oil reservoirs of either the high or medium to low permeability due to the low intrinsic viscosities. The optimum NaAMPS feed amount could not only increase the water solubility, but also facilitate the intermolecular associations. Implementing VBPEO into the polymer greatly increased the rigidity of molecular chains, resulting in a high apparent viscosity of the PVEA in water and the brine solutions. The PVEA brine solutions exhibited both excellent uni‐ and bi‐valent cation resistance, salt‐ and heat‐thickening twice, pseudoplastic behavior, and thixotropy. The SEM morphologies showed that the expanded polymer bundles as well as the associated structures with huge sizes were formed for PVEA in water and that the continuous network structures were still formed in the PVEA brine solutions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1241–1250, 2010
Self‐diffusion of small molecules into rubbery polymers: A lattice free‐volume theory
Authors: Costa L. I. , Storti G.
Published: January 2010

In the framework of the free‐volume (FV) theory, a new equation was derived for the evaluation of self‐diffusion coefficients of small molecules in polymers above the mixture glass transition temperature. The derivation of the equation turned out to be straightforward once the equivalence between the free volume and the unoccupied volume given by thermodynamic lattice theories is assumed. A parameter evaluation scheme is proposed, which is substantially simpler compared with the conventional Vrentas–Duda approach, even without losing generality. The key assumption is discussed, and its consistency is verified from a numerical viewpoint. A comparison with experimental solvent self‐diffusion coefficients for several solvent/polymer binary systems confirmed that the proposed theory presents good correlative ability over wide temperature and composition ranges. Moreover, the introduced thermodynamic foundation allows one to easily include the pressure effect too. In the frame of the proposed lattice free volume theory, the sizes of the polymer jumping units decrease with temperature and increase with pressure. Such behavior converges with theoretical expectations and opens the way for a predictive FV theory. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 529–540, 2010
Spinodal decomposition and phase separation kinetics in nanoclay–biopolymer solutions
Authors: Pawar Nisha , Bohidar Himadri B.
Published: January 2010

Intensity of light, I(q,t), scattered from homogeneous aqueous solutions, of nanoclay (Laponite) and protein (gelatin‐A), was studied to monitor the temporal and spatial evolution of the solution into a phase‐separated nanoclay–protein‐rich dense phase, when the sample temperature was quenched below spinodal temperature, Ts (=311 ± 3 K). The zeta potential data revealed that the dense phase comprised charge‐neutralized intermolecular complexes of nanoclay and protein chains of low surface charge. The early stage, t < 500 s, of phase separation could be described adequately through Cahn‐Hilliard theory of spinodal decomposition where the intensity grows exponentially, I(q, t) = I0 exp.(2R(q)t). The wave vector, q dependence of the growth parameter, R(q) exhibited a maxima independent of time. Corresponding correlation length, 1/qc = ξc was found to be ≈75 ± 5 nm independent of quench depth. In the intermediate regime, anomalous growth described by I(q, t) ∼ tα with α = 0.1 ± 0.02 independent of q was observed. Rheological studies established that there was a propensity of network structures inside the dense phase. Isochronal temperature sweep studies of the dense phase determined the melting temperature, Tm = 312 ± 4 K, which was comparable with the spinodal temperature. The stress‐diffusion coupling prevailing in the dense phase when analyzed in the Doi‐Onuki model yielded a viscoelastic correlation length, ξv determined from low‐frequency storage modulus, G ′0 ≈ kB T/ξ, which was ξv ≈ 35 ± 3 nm indicating 2ξv ≈ ξc. It is concluded that the early stage of phase separation in this system was sufficiently described by linear Cahn‐Hilliard theory, but the same was not true in the intermediate stage. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 555–565, 2010
Effect of alkyl side chain length on the properties of polyetherimides from molecular simulation combined with experimental results
Authors: Pan Rui , Zhao Wei , Zhou Tao , Zhang Aiming
Published: January 2010

Three polyetherimides (PEIs) with the same backbone of Ultem 100 but different lengths of the alkyl side chains were simulated by using molecular dynamics and molecular mechanics techniques to investigate the effect of side chain length on their properties and physical mechanism behind. Simulation results, which are consistent to the experimental data, show that PEI‐5 with four methylene units in each alkyl side chain has higher Tg (glass transition temperature) and higher tensile strength, but lower tensile elongation at break than those of PEI‐6 with five and PEI‐8 with seven methylene units in each alkyl side chain. However, unlike the traditional phenomena, conformational analysis provides that PEI‐5 with the highest Tg gives the highest flexibility to the polymer chain, whereas PEI‐8 with the lowest Tg imparts the lowest flexibility resulting from attachment of longer alkyl side chain increase the rigidity of backbone. From the calculated ratio of the accessible volume to the total volume for each system, the highest ratio of PEI‐8 indicates that long alkyl side chains generate more free volume than short side chains, acting as an internal plasticizer in bulk structure. It is the internal plasticizing effect that is predominantly responsible for the abnormal properties, instead of the rigidity from side chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 595–599, 2010
Exploring the relationship between physical well‐being and healthy lifestyle changes among European‐ and Latina‐American breast and cervical cancer survivors
Authors: Ashing‐Giwa Kimlin T. , Lim Jung‐Won , Gonzalez Patricia
Published: January 2010

Background: Cancer and its treatments have a lingering and often negative impact on survivors' physical well‐being. The physical sequelae impinge on daily functioning and overall HRQOL, and perhaps influence lifestyle changes post‐cancer. This study aims to examine: (1) physical well‐being items that are associated with low overall health‐related quality of life; and (2) the relationship between physical well‐being outcomes and healthy lifestyle changes by cancer type.

Methods: This study employed a cross‐sectional design with mixed sampling methods. In total 922 European‐ (n=452) and Latina‐American (n=470) breast (BCS) or cervical cancer survivors (CCS) were recruited from the California Cancer Surveillance Program and Los Angeles area hospital registries. Item responses from survivors in the lowest quartile of total quality of life scores and percentages reflecting low physical well‐being levels were calculated.

Results: A statistical approach to individual items provides unique and valuable measurement and clinical information above and beyond physical well‐being total scores. Physical well‐being item responses varied according to ethnicity, income, and education. BCS and CCS showed different patterns in the relationship between physical well‐being items and lifestyle changes. Specifically, exercise was significantly related to physical well‐being items for BCS, while diet changes were significantly associated with physical well‐being for CCS.

Conclusions: Results reveal unique correlates of physical well‐being items by cancer type, ethnicity, and lifestyle changes. Clinically, this study highlights the need for greater consideration of individual and medical characteristics in developing culturally sensitive and patient responsive interventions to promote healthy lifestyles and improve survivorship outcomes. Copyright © 2010 John Wiley & Sons, Ltd.
Deficiency of glycine N‐methyltransferase results in deterioration of cellular defense to stress in mouse liver
Authors: Liao Yi‐Jen , Chen Kuan‐Hsuan , Huang Shiu‐Feng , Chen Tzu‐Lang , Wang Chung‐Kwe , Chien Chau‐Heng , Tsai Ting‐Fen , Liu Shih‐Ping , Chen Yi‐Ming Arthur
Published: January 2010

Purpose: Previously, we reported that glycine N‐methyltransferase (GNMT) interacts with benzo[a]pyrene (BaP) and inhibits BaP‐DNA adducts formation. In addition, Gnmt knockout (Gnmt−/−) mice developed chronic hepatitis and hepatocellular carcinoma (HCC). The aims of this study were to understand the gene expression profile of Gnmt−/− mice and to study the interaction between BaP and GNMT deficiency in vivo.

Experimental design: Gene expression profiles of Gnmt−/− mice were analyzed by 2‐D PAGE and real‐time PCR. Both wild‐type and Gnmt−/− mice were challenged with BaP and sacrificed at the age of 13 months.

Results: Compared with the wild‐type mice, proteins involved in the anti‐oxidation/detoxification response, glycolytic energy metabolism and one‐carbon metabolism pathways were down‐regulated significantly in Gnmt−/− mice. Malondialdehyde assay showed that lipid peroxidation was significantly increased in the Gnmt−/− mice liver. H2O2 treatment demonstrated that the survival rate of HuH‐7 cells overexpressing GNMT was significantly higher than the controls. BaP challenge experiments showed that 71.4% (5/7) of male and all (7/7) female Gnmt −/− mice developed HCC, while only 16.7% (1/6) of male and 20% (1/5) of female wild‐type mice had HCC.

Conclusion and clinical relevance: GNMT regulates genes related to detoxification and anti‐oxidation pathways. BaP is a liver cancer carcinogen especially during GNMT deficiency.
MS analysis of rheumatoid arthritic synovial tissue identifies specific citrullination sites on fibrinogen
Authors: Hermansson Monika , Artemenko Konstantin , Ossipova Elena , Eriksson Hanna , Lengqvist Johan , Makrygiannakis Dimitrios , Catrina Anca I. , Nicholas Anthony P. , Klareskog Lars , Savitski Mikhail , A. Zubarev Roman , Jakobsson Per‐Johan
Published: January 2010

Purpose: Citrullination is a post‐translational modification of arginine residues to citrulline catalyzed by peptidyl arginine deiminases. Induced expression of citrullinated proteins are frequently detected in various inflammatory states including arthritis; however, direct detection of citrullination in arthritic samples has not been successfully performed in the past.

Experimental design: Citrullination of human fibrinogen, a candidate autoantigen in arthritis, was studied. Accurate identification of citrullinated fibrinogen peptides from rheumatoid arthritis synovial tissue specimens was performed using accurate mass and retention time analysis.

Results: A peptide with the sequence ESSSHHPGIAEFPSRGK corresponding to amino acids 559–575 of fibrinogen α‐chain was identified to be citrullinated with an occupancy rate between 1.4 and 2.5%. Citrullination of the peptide KREEAPSLRPAPPPISGGGYRARPAK corresponding to amino acids 52–77 of the fibrinogen β‐chain was identified with an occupancy rate of 1.2%.

Conclusions and clinical relevance: We report a proof of principle study for the identification of citrullinated proteins and within them, identification of citrullination sites and quantification of their occupancies in synovial tissue from rheumatoid arthritis patients using high‐resolution MS. Detailed studies on which molecules are citrullinated in arthritis can provide information about their role in immune regulation and serve as novel biomarkers and potentially even as therapeutic targets.
Structural evolution of ZnO films deposited by rf magnetron sputtering on glass substrate
Authors: Liao Yan‐Ping , Zhang Jian‐Hua , Li Shu‐Xin , Guo Zhan‐Sheng , Cao Jin , Zhu Wen‐Qing , Li Xifeng
Published: January 2010

Influences of O2/Ar flux ratio (R) on surface morphology and structural evolution have been studied in the case of ZnO films deposited on glass substrates by radio‐frequency (rf) magnetron sputtering. Results of atomic force microscopy (AFM), X‐ray diffraction, and X‐ray photoelectron spectroscopy (XPS) clearly indicate that the surface root‐mean‐square (rms) roughness, crystallinity, stress, and defects strongly depend on the R. At R = 1/2, the crystallized ZnO film with highly c‐axis orientation and highly smooth surface has been obtained. The implication of these results is that a moderate R is needed to realize high‐quality ZnO film.
Current‐transport studies and trap extraction of hydrothermally grown ZnO nanotubes using gold Schottky diode
Authors: Amin G. , Hussain I. , Zaman S. , Bano N. , Nur O. , Willander M.
Published: January 2010

High‐quality zinc oxide (ZnO) nanotubes (NTs) were grown by the hydrothermal technique on n‐Si substrate. The room temperature (RT) current‐transport mechanisms of Au Schottky diodes fabricated from ZnO NTs and nanorods (NRs) reference samples have been studied and compared. The tunneling mechanisms via deep‐level states was found to be the main conduction process at low applied voltage but at the trap‐filled limit voltage (VTFL) all traps were filled and the space‐charge‐limited current conduction was the dominating current‐transport mechanism. The deep‐level trap energy and the trap concentration for the NTs were obtained as ∼0.27 eV and 2.1 × 1016 cm–3, respectively. The same parameters were also extracted for the ZnO NRs. The deep‐level states observed crossponds to zinc interstitials (Zni), which are responsible for the violet emission.
Alternating‐current conductance and capacitance of a diamond diode in the presence of deep‐level impurities
Authors: Rodrigues Ana
Published: January 2010

The alternating‐current conductance and capacitance of a diamond film/aluminium diode was measured over the temperature range 230–330 K. Loss tangent curves for the frequency range 100 Hz–1 MHz exhibited three maxima. Doping of the CVD diamond was not uniform, indicating the presence of deep‐level impurities. Results were analysed for the temperature range 230–270 K, at which it is possible to observe processes that are supposed to occur in grains and grain boundary regions of polycrystalline diamond. A loss tangent curve was simulated using an equivalent circuit model composed of resistances and capacitances corresponding to depletion regions and the bulk and of the electrical characteristics of the two phases of diamond. This model explicitly includes deep impurities. The curve‐fitting parameters for the loss tangent plot demonstrate that at medium frequency (4 kHz, activation energy 0.2 eV) the bulk resistance is high (100 kΩ) and the maximum is related to the presence of microcrystals, which exhibit low conductivity. At high frequency (800 kHz, activation energy 0.5 eV) the bulk resistance is low (1 kΩ), suggesting that the maximum is associated with grain boundary regions. The low values of the relaxation times obtained (10–28 and 4×10–27 s) are justified. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of poly‐Si/SiGe gate in CMOS transistors for RF and microwave circuit applications
Authors: Jimenez H. G. , Manera L. T. , Rautemberg M. F. , Diniz J. A. , Doi I. , Tatsch P. J. , Figueroa H. E. , Swart J. W.
Published: January 2010

A reduction of gate depletion and DC characteristics in CMOS transistors with poly‐Si/SiGe Gate stack fabricated with local CMOS process is presented. Our local CMOS process uses a single n+ doped, poly‐Si/SiGe gate material. After deposition, both the poly‐Si and the SiGe used as gate layers were implanted by phosphorus ions. The parameters on threshold, sub‐threshold and low frequency noise 1/f of poly‐Si/SiGe CMOS transistors are reported. Our results demonstrate that the shift in threshold voltage due to the presence of Ge in the gate material is apparent from the p‐MOS and n‐MOS device characteristics. The drive current turn‐on in the I‐V characteristics increases compared with conventional CMOS transistors with poly‐Si gate and devices show low 1/f noise which make them promising devices for RF and microwave circuit applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface exfoliation in ZnO by hydrogen implantation and its smoothening by high temperature annealing
Authors: Singh Trilok , Scholz R. , Christiansen S. H. , Gösele U. , Singh R.
Published: January 2010

Zinc oxide (0001) bulk crystals were implanted by 100 keV H2+ ions with various fluences in the range of 5×1016 to 3×1017 cm–2. Surface layer exfoliation was observed in the case of samples that were implanted with fluence higher than 2.5×1017 cm–2, either in the as‐implanted state or after annealing at higher temperatures up to 500 °C. The roughness of the exfoliated surfaces, as measured using atomic force microscopy, was found to be about 20 nm. These samples with exfoliated surfaces were further annealed at higher temperatures up to 1000 °C under air atmosphere. The surface morphology of the samples was studied using Nomarski optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The defect characterization in the implanted ZnO samples was performed using transmission electron microscopy (TEM). Cross‐sectional TEM measurements showed the formation of hydrogen filled nanovoids inside the damage band in ZnO. It was observed that after annealing the samples at 960 °C for 1 hr in air ambient, the roughness of the exfoliated surfaces reduced down to about 3 nm. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study on the correlation between dielectric constant and chemical shift in FTIR spectra of SiOC film by chemical vapor deposition after annealing
Authors: Oh Teresa
Published: January 2010

SiOC films made by the inductively coupled plasma chemical vapor deposition were researched the relationship between the dielectric constant and the chemical shift. SiOC film had the main Si‐O‐C bond with the molecule vibration mode in the range of 930∼1230 cm‐1 which consists of C‐O and Si‐O bonds related to the cross link formation according to the dissociation and recombination. The C‐O bond originated from the elongation effect by the neighboring highly electronegative oxygen atoms at terminal C‐H bond in Si‐CH3 of 1270 cm‐1. However, the Si‐O bond was formed from the second ionic sites recombined after the dissociation of Si‐CH3 of 1270 cm‐1. Increment of Si‐O bond in the Si‐O‐C main bond contributed to increase the hardness and decrease the roughness because of the decreasing of the carbon content witch is related to the space effect. The dielectric constant of SiOC film was decreased by lowering the polarization which consists of the ionic and electronic polarity. Increment of Si‐O bond in a right shoulder at the main bond was interpreted by the red shift observed in FTIR spectra. Moreover, the increment of Si‐O bond and decrement of carbon content induced to decrease the ionic polarity and then decreased the dielectric constant. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of nitrogen on the InAs/GaAs quantum dot formation
Authors: Ivanova L. , Eisele H. , Lenz A. , Timm R. , Schumann O. , Geelhaar L. , Riechert H. , Dähne M.
Published: January 2010

We studied the influence of nitrogen incorporation on the InAsN/GaAs quantum dot formation using cross‐sectional scanning tunneling microscopy. Upon nitrogen exposure during InAs growth, rather strong dissolution effects occur, leading to the formation of extended almost spherical InGaAs quantum dots with a low indium content and almost free of nitrogen. In this paper we will discuss in particular the detailed stoichiometry determination of the quantum dots. Furthermore, we will demonstrate that nitrogen atoms are located in the surrounding GaAs matrix.

Indium atoms are found underneath the nominal base plane, where quantum dot growth started, demonstrating strong strain‐induced intermixing already during quantum dot formation. The observed strong separation of indium and nitrogen is related to a rather low solubility of nitrogen within InAs as compared with GaAs. Finally, a schematic model for the growth of InAs and InAsN quantum dots in GaAs will be discussed in detail (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of wurtzite–zinc‐blende interfacial energy on growth and crystal phase of the III‐V nanowires
Authors: Lubov Maxim , Kulikov Dmitrii , Trushin Yuri
Published: January 2010

Influence of wurtzite–zinc‐blende energy on nucleation rate and growth kinetics is studied. The physical model of III‐V nanowires growth is proposed. We show that wurtzite–zinc‐blende interfacial energy caused formation of the zinc‐blende structure on the initial stage of nanowires growth. Role of the fluctuations in quasi‐periodic crystal structure formation representing alternating layers of wurtzite and zinc‐blende phase is revealed. Calculations of the growth of the nanowire growth accounting fluctuations in the droplet alloy are carried out. The results of the calculations are in a good agreement with available experimental data. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence and diode characteristic of ZnO thin films/junctions fabricated by pulsed laser deposition (PLD) technique
Authors: Sasaki Kazuhiro , Komiyama Takao , Chonan Yasunori , Yamaguchi Hiroyuki , Aoyama Takashi
Published: January 2010

ZnO:Ga and ZnO:P films were grown by a pulsed laser deposition (PLD) technique changing the dopant concentrations, and their photoluminescence (PL) spectra were obtained. Then, ZnO:P/ZnO:Ga junctions were fabricated and their junction characteristics were evaluated. As the Ga concentration increased in the films, the PL intensity was decreased while as the P concentration increased, the PL intensity was increased. The maximum PL intensities were obtained for the films of 0.5%(Ga) and 7.0% (P), respectively. Rectifying junction characteristics were observed only for the combination of 0.5‐1.0% (Ga) and 5.0% (P) films. Mutual dopant diffusion is supposed to explain the relation between the PL and the junction characteristics. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Establishing strategic CSR in SMEs: an Austrian CSR quality seal to substantiate the strategic CSR performance
Authors: Gelbmann Ulrike
Published: January 2010

Integrating CSR into their strategy system can help enterprises to produce a competitive advantage. This can both add to their long‐term prosperity and help increase overall sustainability, provided they use a broad, dynamic approach to CSR that is compatible with strategic management. SMEs in particular often feature excellent responsibility performance, without realizing it and without trying to benefit from it.

In Austria, as in other countries, SMEs often suppose CSR to be a domain of large enterprises: too bureaucratic, expensive, time‐consuming and complex. This paper presents a case from Austria, the development of an official CSR Quality Seal directed at SMEs to help them communicate their sustainability performance effectively and display a visible sign for their stakeholders. The seal was devised to meet objections to the application of standardized CSR tools in industry, especially in SMEs. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Designing a sequentially randomized study with adherence enhancing interventions for diabetes patients
Authors: Buyze Jozefien , Van Rompaye Bart , Goetghebeur Els
Published: January 2010

Adaptive treatment strategies can change treatment prescription over time in response to intermediate outcomes. They are the natural choice for treating chronic diseases or for prevention, since the condition of subjects tends to change over the long term. Similarly, flexible intervention strategies are vital for generating or sustaining better adherence in long term treatment settings. When a cost‐efficient first‐line treatment is available, for instance, good adherence is expected to help delay or avoid second‐line treatment.

Sequentially randomized trials enable unbiased evaluation of how to best adapt adherence supporting interventions to a history of outcomes and adherence with the goal to optimize future treatment response. In this paper we propose and study different sequential designs targeting cost‐efficient control of type II diabetes under first‐line treatment through two different classes of adherence support: by (bio)technical and by behavioural means. We study their respective and joint impact first through double factorial adaptive designs, where interventions are triggered by an elevated risk of current treatment failure predicted by poor surrogate response.

We develop the double factorial design and several derived designs that are more cost‐efficient in the context of managed care of diabetes patients. We evaluate the marginal responses over time to different adaptive treatment strategies by means of doubly robust estimators. We consider sample sizes needed to thus detect realistic and worthwhile effects and discuss the relative practical and theoretical merits of the separate designs. Copyright © 2010 John Wiley & Sons, Ltd.