bluuebunny/crossref_metadata_2025_split huggingface dataset:
CLU, CR1 and PICALM genes associate with Alzheimer's-related senile plaques
Authors: Kok Eloise H , Luoto Teemu , Haikonen Satu , Goebeler Sirkka , Haapasalo Hannu , Karhunen Pekka J 
Published: April 2011

Abstract
Introduction
APOE is the strongest risk gene for sporadic Alzheimer's disease (AD) so far. Recent genome wide association studies found links for sporadic AD with CLU and CR1 involved in Aβ clearance, and PICALM affecting intracellular trafficking.

Methods
We investigated the associations of senile plaques (SP) and neurofibrillary tangles (NFT) with the proposed risk genes and APOE, in the Tampere Autopsy Study (TASTY) series (603 cases), a sample of the general population (0 to 97 yrs), who died out-of-hospital.

Results
Age and the APOEε4 allele associated strongly with all phenotypes of SP, as expected. In age and APOEε4 adjusted analyses, compared to the most common homozygous genotype, burnt out SP were more common among carriers of the C-allele of CLU, whereas the T-allele of PICALM and C-allele of CR1 were linked with lower SP coverage. We found no significant associations between any of the genetic variants and NFT.

Conclusions
Marginal effects from CLU, CR1 and PICALM suggest that these genes have minimal effects on the development of AD lesions.
Treatment of experimental adjuvant arthritis with a novel folate receptor-targeted folic acid-aminopterin conjugate
Authors: Lu Yingjuan , Stinnette Torian W , Westrick Elaine , Klein Patrick J , Gehrke Mark A , Cross Vicky A , Vlahov Iontcho R , Low Philip S , Leamon Christopher P 
Published: April 2011

Abstract
Introduction
Folate receptor (FR)-expressing macrophages have been shown to accumulate at sites of inflammation, where they promote development of inflammatory symptoms. To target such a macrophage population, we designed and evaluated the biologic activity of EC0746, a novel folic acid conjugate of the highly potent antifolate, aminopterin.

Methods
Using a FR-positive subclone of murine macrophage-derived RAW264.7 cells and rat thioglycollate-elicited macrophages, we studied the effect of EC0746 on dihydrofolate reductase activity, cell proliferation, and cellular response towards bacterial lipopolysaccharide as well as IFNγ activation. The EC0746 anti-inflammatory activity, pharmacokinetics, and toxicity were also evaluated in normal rats or in rats with adjuvant-induced arthritis; that is, a FR-positive macrophage model that closely resembles rheumatoid arthritis in humans.

Results
EC0746 suppresses the proliferation of RAW264.7 cells and prevents the ability of nonproliferating rat macrophages to respond to inflammatory stimuli. In the macrophage-rich rat arthritis model, brief treatment with subcutaneously administered EC0746 is shown to mediate an FR-specific anti-inflammatory response that is more potent than either orally administered methotrexate or subcutaneously delivered etanercept. More importantly, EC0746 therapy is also shown to be ~40-fold less toxic than unmodified aminopterin, with fewer bone marrow and gastrointestinal problems.

Conclusions
EC0746 is the first high FR-binding dihydrofolate reductase inhibitor that demonstrates FR-specific anti-inflammatory activities both in vitro and in vivo. Our data reveal that a relatively toxic anti-inflammatory drug, such as aminopterin, can be targeted with folic acid to inflammatory macrophages and thereby relieve inflammatory symptoms with greatly reduced toxicity.
Highly Sensitive Troponin Assays and the Cardiology Community: A Love/Hate Relationship?
Authors: de Lemos James A , Morrow David A , deFilippi Christopher R 
Published: April 2011

Abstract
The development of highly sensitive assays for cardiac troponin T (hs-cTnT)4 and cardiac troponin I (hs-cTnI) represents the latest technological advance in a field that has witnessed continual progression toward more sensitive and more precise tools for detecting cardiac injury. The hs-cTnT assay, for example, can detect cTnT concentrations 10-fold lower than the current fourth-generation assay, with high precision at the myocardial infarction (MI) detection limit. Despite the potential for such evolution to improve patient care, clinicians, including practicing cardiologists, often find themselves poorly prepared for the introduction of more-sensitive assays, because they fail to consider the implications of increasing sensitivity on the interpretation of the test results. We believe that highly sensitive troponin assays offer new opportunities to improve cardiovascular health, but they also present challenges in the areas in which troponin testing is most commonly used today.
Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood
Authors: Schütt Fokko , Puls Jürgen , Saake Bodo 
Published: April 2011

Abstract
Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.
The Relationship Between Relative Solvent Accessibility and Evolutionary Rate in Protein Evolution
Authors: Ramsey Duncan C , Scherrer Michael P , Zhou Tong , Wilke Claus O 
Published: April 2011

Abstract
Recent work with Saccharomyces cerevisiae shows a linear relationship between the evolutionary rate of sites and the relative solvent accessibility (RSA) of the corresponding residues in the folded protein. Here, we aim to develop a mathematical model that can reproduce this linear relationship. We first demonstrate that two models that both seem reasonable choices (a simple model in which selection strength correlates with RSA and a more complex model based on RSA-dependent amino acid distributions) fail to reproduce the observed relationship. We then develop a model on the basis of observed site-specific amino acid distributions and show that this model behaves appropriately. We conclude that evolutionary rates are directly linked to the distribution of amino acids at individual sites. Because of this link, any future insight into the biophysical mechanisms that determine amino acid distributions will improve our understanding of evolutionary rates.
Lesser-known piezoelectric and pyroelectric applications of electroactive polymers
Authors: Lang Sidney B. , Muensit Supasarote 
Published: April 2011

ABSTRACTThe piezoelectric effect was first observed in polyvinylidene fluoride polymer (PVDF) in 1969 and the pyroelectric effect was found several years later. A number of additional ferroelectric polymers have been discovered since that time including the copolymer PVDF with trifluoroethylene (P(VDF-TrFE)), and the odd-numbered nylons. A large number of applications of piezoelectricity and pyroelectricity have been developed. The magnitudes of the effects in polymers are much lower than those of ferroelectric ceramics (an exception is the piezoelectric effect in porous polymers). However, other factors make these very desirable materials for applications. The polymers have low permittivities, low acoustic impedances and low thermal conductivities. They are available in large area sheets and they are flexible and relatively low in cost. Major applications include microphones and loudspeakers, ultrasonic devices, SAW transducers, actuators, infrared detectors and many others. This review will describe some of the lesser-known applications of these materials in the fields of tactile devices, energy conversion, porous polymers, property measurement, pyroelectric infrared sensors, shock sensors and space science.
Modeling the Chemo-mechanical Behavior of Reactive Polymer Gels
Authors: Yashin Victor V. , Balazs Anna C. 
Published: April 2011

ABSTRACTWe consider a theoretical model of a reactive polymer gel in which the reaction can proceed in an oscillatory regime and generate traveling chemical waves accompanied by waves of local swelling-deswelling. This type of gel could be used for fabricating chemo-mechanical devices with self-sustained rhythmic action, and gel-based pumps. We assume that the Belousov-Zhabotinsky (BZ) reaction takes place in the reactive gel. The BZ reaction generates periodic reduction-oxidation (redox) changes of a metal catalyst covalently bonded to a hydrogel that is immersed in a solution containing the rest of the BZ reagents. The redox changes in the metal affect the polymer-solvent interactions, resulting in variations in the gel volume. The self-oscillation of the gel volume, and the traveling waves of local swelling in a hydrogel with the BZ reaction have been experimentally observed by Yoshida and co-workers. To describe the system theoretically, we employ the Oregonator model of the BZ reaction, and the two-fluid model of gel dynamics. Propagation of one-dimensional wave trains through the reactive gel is simulated. The structure of the traveling swelling-deswelling waves is studied.
Interfaces and Space Charge in Polymeric Insulating Materials
Authors: Chen George 
Published: April 2011

ABSTRACTIn this paper, the influence of interface between electrode and polymer or polymer and polymer on space charge dynamics has been studied. Planar samples of low density polyethylene (LDPE) were subjected to high dc electric stresses for extended periods of time and space charge measurements were taken using the pulsed electroacoustic (PEA) technique. Common electrode materials used in either laboratory or power cable industry were selected (i.e. aluminium (Al), gold (Au) and carbon loaded XLPE (Sc)). Experimental results demonstrated that charge injection processes take place in all cases once the applied electric stress has exceeded a threshold value. However, the amount of charge and polarity of the dominant injected charges showed significant dependence on the electrode materials (under the same applied electric stress). Having establishing the influence of electrode materials on charge accumulation, our attention was then focused on the effect of polymer/polymer interface on charge dynamics. Unlike our previous approach where two different polymeric materials were used, this time the polymer/polymer interface was formed by using two layer of LDPE films cut from the same sheet. Sc and Al were used as electrodes to form different combinations. The results clearly indicated that the interface between two layers of LDPE acts as traps for electrons but not for positive charge carriers. The charge distribution in the bulk of the sample strongly depends on the electrode materials.
Phase Stability in heavy f-Electron Metals from First-Principles Theory
Authors: Söderlind Per 
Published: April 2011

AbstractThe structural phase stability of heavy f-electron metals is studied by means of density-functional theory (DFT). These include temperature-induced transitions in plutonium metal as well as pressure-induced transitions in the trans-plutonium metals Am, Cm, Bk, and Cf. The early actinides (Th-Np) display phases that could be rather well understood from the competition of a crystal-symmetry breaking mechanism (Peierls distortion) of the 5f states and electrostatic forces, while for the trans-plutonium metals (Am-Cf) the ground-state structures are governed by 6d bonding. We show in this paper that new physics is needed to understand the phases of the actinides in the volume range of about 15-30 Å3. At these volumes one would expect, from theoretical arguments made in the past, to encounter highly complex crystal phases due to a Peierls distortion. Here we argue that the symmetry reduction associated with spin polarization can make higher symmetry phases competitive. Taking this into account, DFT is shown to describe the well-known phase diagram of plutonium and also the recently discovered complex and intriguing high-pressure phase diagrams of Am and Cm. The theory is further applied to investigate the behaviors of Bk and Cf under compression.
A First-Principles Study of the (111), (001) and (110) Surfaces of delta -Pu
Authors: Gong Haoran , Ray Asok K 
Published: April 2011

AbstractFull-potential linearized-augmented-plane-wave (FP-LAPW) calculations for δ-Pu films up to seven layers at the ground antiferromagnetic state including spin-orbit coupling effects reveal that surface energy rapidly converges and the semi-infinite surface energy is predicted to be 1.18, 1.21, and 1.42 J/m2 for δ-Pu (111), (001), and (110) films, respectively. Density of states show that the 5f electrons of the three surfaces tend to be localized with a sequence of (111)→(001)→(110). It is also predicted that the work function of δ-Pu (110) films exhibits a quantum size effect up to seven layers, while the work functions of δ-Pu (001) and (111) films show some oscillations when the number of layers is less than five, while it becomes relatively stable when the number of layers is greater than five. In addition, the work functions are predicted to be 3.41, 3.11, and 2.99 eV for δ-Pu (111), (001), and (110) films at the ground state, respectively. Comparisons with available experimental and theoretical results in the literature show good agreement.
Studies of Structural and Electronic Properties of Uranium Compounds, by XANES Spectroscopy
Authors: Fillaux Clara , Den Auwer Christophe , Guillaumont Dominique , Simoni Eric , Barré Nicole , Shuh David K. , Tyliszczak Tolek 
Published: April 2011

AbstractX-ray absorption near edge structure (XANES) is a sensitive probe of the electronic structure, and can provide information about the valency, the unoccupied electronic states and the effective charge of the absorbing atom. In this paper, near edge x-ray absorption fine structure spectra are reported at the L3, M5 and N5 thresholds and used to determined structural and electronic properties of U(VI) within uranyl nitrate (UO2(NO3)2.6H2O) and perovskite (Ba2ZnUO6). Experimental data analysis by simulating the absorption edge allows to compare the coordination polyhedrons, identify the electronic transitions and calculate the density of states associated with the absorption spectra. Moreover, a coupling between simulations of the experimental spectra and quantum chemical calculations is performed, in order to improve the model describing the final states and better understand the bonding properties of the cation with the ligand.
The optical properties of a polished uranium surface and its epitaxial oxide, and the rate of oxide growth determined by spectrophotometry
Authors: Siekhaus Wigbert J , Nelson Art J 
Published: April 2011

AbstractWide-band reflectrometry and ellipsometry have been used to determine the optical properties n and k of freshly polished uranium and of the epitaxial oxide layer, and also the rate of oxide growth in air. Results for uranium metal as well as for epitaxial oxide are compared with single wavelength ellipsometry literature values.
Combinatorial Studies of Switching and Solid-Phase Crystallization in Amorphous Silicon
Authors: Stradins Paul , Branz Howard M. , Hu Jian , Ward Scott , Wang Qi 
Published: April 2011

AbstractCombinatorial approaches are successfully applied for the optimization of electric write-once, thin-film Si antifuse memory devices, as well as for studying the solid-phase epitaxy kinetics of amorphous silicon on c-Si. High forward, low reverse current thin film Si diode deposition recipes are selected using cross-strips of different combinations of amorphous and microcrystalline doped layers, as well as a thickness-wedged intrinsic a-Si:H buffer layer. By studying switching in thickness-wedged a-Si:H layers, it is found that switching requires both a critical field and a critical bias voltage across the metallic contacts. Solid-phase epitaxy speed has a non-linear dependence on the film thickness, which is easily observed by optical image monitoring and analysis in wedged a-Si:H films on c-Si wafers.
Evaluation of Mo-based Amorphous Alloy Thin Films Exhibiting High Crystallization Temperature
Authors: Sakurai Junpei , Hata Seiichi , Yamauchi Ryusuke , Shimokohbe Akira 
Published: April 2011

AbstractThis paper presents the characteristics of Mo-based (Mo-Zr based) amorphous alloys exhibiting a high crystallization temperature. In order to investigate the alloy composition showing an amorphous state in the Mo-Zr-X (X=Si and Al) alloy system, thin film libraries were prepared at first by combinatorial arc plasma deposition (CAPD). The composition region corresponding to the amorphous state was identified in the libraries with X-ray diffraction. On the basis of the alloy composition and phase distribution of the thin film libraries, additional amorphous Mo-Zr-Si and Mo-Zr-Al thin films were prepared by a carousel sputtering system. The crystallization temperature Tc of the amorphous Mo50Zr(50-x)Six thin films exceeded 1073 K. However, the Mo-Zr-Si thin films were so brittle that they could not be subjected to tensile testing. In the Mo-Zr-Al thin films, Tc of the Mo-rich MoxZr(90-x)Al10 and MoxZr(76-x)Al24 thin films exceeded 973 K. Although the toughness of Mo-based amorphous alloy thin films could be improved slightly by adding Al, the amorphous Mo-Zr-Al thin films were also brittle.
A novel method for the determination of optical properties of absorbing thin films with thickness variations
Authors: Baek Jonghoon , Kovar Desiderio , Keto John W. , Becker Michael F. 
Published: April 2011

AbstractNon-uniformity in the thickness of thin films can severely distort their transmission spectra as compared to those of flat, smooth films. Methods that extract properties such as refractive index, thickness, and extinction coefficient of such films can suffer inaccuracies when applied to wedged or rough films. In order to accurately extract optical properties of non-uniform films, we have developed a novel numerical method and efficient constitutive relations that can determine film properties from just the transmission spectrum. The Optimum Parameter Extraction (OPE) method can accommodate transparent or absorbing films thickness variations that result in significant errors in the values of refractive index and film thickness if not considered. A packing-density model was proposed and used for refractive index to accelerate the fitting routine and to avoid finding local minima instead of the global minimum. In this model, refractive index has one fitting parameter, the packing density, p. Therefore, the OPE method takes a shorter time and produces more accurate results than many other methods. We show that for actual PLD (Pulsed Laser Deposition) AlN thin films, properties such as refractive index, extinction coefficient, and film thickness were very accurately determined using our OPE method. These results are compared with two previous techniques to determine properties of thin films, and the accuracy and applicable conditions for all of these methods are discussed.
The Investigation of the Effects of Polyelectrolyte Attributes on Complex Coacervate Properties using High-Throughput Formulation and Characterization Techniques
Authors: Lochhead Robert , Huisinga Lisa R. , Edwards Christina , Hill Anthony 
Published: April 2011

AbstractFormulators of complex mixtures have long known that the characteristics of their final formulation and the position of “equilibrium” often depends critically upon the order of addition of ingredients and the precise processing conditions under which the formulation was made. The large variety of possible outcomes derive from the many eigenstates that are available to each composition of a complex mixture due to the fact that the bonds between the component molecules are weak physical bonds and therefore a potential multitude of nanostructures can be formed. This is especially true of systems comprising polyelectrolytes and oppositely charged surfactants in the semi-dilute regime, because both polyelectrolyte conformation and surfactant micellar association structures are strongly influenced by the ionic environment of the polymer and surfactant molecules. This is especially important for 2-in-1 shampoos that depend upon the spontaneous creation of a polyelectrolyte/surfactant coacervate to deposit active conditioning, styling or antidandruff ingredients during the shampoo process. The investigation of the effects of order of addition requires exanimation of a myriad of samples and it is virtually impossible by conventional techniques. This task is ideally suited to investigation by a combinatorial approach aimed at the generation of libraries of pseudo-phase diagrams. In this study we developed a high-throughput screening method to generate phase diagrams over a large range of concentrations for cationic polysaccharide interaction with anionic surfactant in the presence and absence of dissolved electrolyte. Using a liquid handling system for sample preparation, we are able to analyze nearly 1000 samples per day, making the above goals of understanding electrolyte effects and coacervate structure-property relationships attainable.
Automated Scanning Probe Microscopy for Combinatorial Polymer Research
Authors: Wouters Daan , Alexeev Alexander , Kozodaev Dmitri , Saunin Sergey , Schubert Ulrich 
Published: April 2011

AbstractWith the development of combinatorial materials research (CMR) methods and high throughput experimentation (HTE) workflows for polymer research applications, the demand for automated, high throughput characterization methods is evident. Solution-based characterization methods like NMR, GPC, viscosimetry, for example and UV-Vis as well as fluorescence plate readers are available. Here we report on the incorporation of automated scanning probe microscopy in the HTE-workflow by demonstrating the evaluation of surface properties and topographies for thin polymer film libraries.
Probing the Interfacial Adhesion Strength in Compositional Libraries of Epoxy Films
Authors: Stafford Christopher M , Kim Jae Hyun , Kawaguchi Daisuke , Royston Gareth , Chiang Martin Y.M. 
Published: April 2011

AbstractWe are developing a measurement platform, based on the edge delamination test geometry, geared towards combinatorial and high-throughput (C&HT) assessment of interfacial adhesion and reliability of epoxy films bonded to a rigid substrate. A critical parameter space to be explored is composition of the epoxy formulation. We have constructed an automated mixing and deposition system for creating discrete and continuous gradients in composition of viscous epoxy formulations. By dicing the combinatorial library into a contiguous discrete sample array, the interfacial adhesion strength can be deduced from the critical stress required to debond each film cell from the substrate. These results can be used to predict the adhesion reliability of epoxy formulations as a function of composition and applied stress.