bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cognitive Impairment in Parkinson's Disease: Is It a Unified Phenomenon?
Authors: Lowit Anja , Howell Peter , Brendel Bettina 
Published: November 2005

AbstractParkinson's disease (PD) has long been associated with dementia. This has been found to correlate with participant age, age at onset of PD and severity of PD. In addition, a large corpus of research points to the fact that participants with, as well as without, dementia can be impaired in a variety of cognitive tasks. Among these, set-shifting and dual-tasking skills have received particular focus. Most studies report that a reduction in attentional resources can lead to problems with these tasks. However, none have been able to determine exactly which systems are involved in these skills and which neurological impairments underlie the observed cognitive deficits. The current study set out to investigate how performance on tasks requiring set-shifting and dual tasking related to each other, as well as overall measures of cognition gained across a variety of tasks. Fifteen participants with PD and 12 control participants underwent screening tests for dementia, as well as specific tests to assess attention, set-shifting and dual tasking. The results indicate that set-shifting ability correlated well with other measures of cognitive performance, whereas dualtasking skills did not. This could suggest that set-shifting and dual tasking are not necessarily controlled by the same process, or that a particular process is involved to different degrees. In addition, many participants showed individual performance variations and dissociations between tasks that were not necessarily evident from the statistical analysis. This indicates that it can be difficult to make assumptions on overall cognitive performance from specific tasks and vice versa. This observation has implications for clinical practice as well as research methodology.
Adjusting to Change Through Song: Themes in Songs Written by Clients With Traumatic Brain Injury
Authors: Baker Felicity , Kennelly Jeanette , Tamplin Jeanette 
Published: November 2005

AbstractThe study aimed to identify themes in songs written by clients with traumatic brain injury (TBI). Lyrics (1834) from 82 songs written by 11 female and 21 male clients aged between 5 and 60 years were categorised into 8 main themes and 24 subcategories. Incidence of subcategories and themes were calculated. Self-reflections and messages were the most frequent themes portrayed within songs. Memories and reflections about significant others were also frequently communicated. It was noticeable that clients felt safer to communicate thoughts and feelings about the past and present but were less inclined to confront the future.
Rational engineering of a fluorescein-binding anticalin for improved ligand affinity
Authors: Vopel Sven , Mühlbach Hermine , Skerra Arne 
Published: November 2005

Abstract
The anticalin FluA is an artificial lipocalin with novelspecificity for the fluorescein group, which was engineered from an insect bilin-binding protein by targeted random mutagenesis and selection. Based on the crystal structure of FluA, an attempt was made to improve the complementarity of its ligand pocket to fluorescein by rational protein design. Several side chains participating in sub-optimal interactions with the ligand were identified and replaced by residues that promised a better steric fit. As a result, the substitution of Ala45 by Ile and of Ser114 by Thr or Arg led to a tight affinity of ca. 1 nM, which is approximately 30-fold better than that of the parental anticalin. Similar to the original FluA, the improved version shows almost complete quenching of the bound ligand fluorescence. Interestingly, the quenching effect was significantly reduced when Trp129 was replaced by Tyr, thus supporting the previously postulated role of this residue, which closely packs against the bound ligand, for efficient electron transfer to the excited fluorescein. Circular dichroism spectra revealed that all variants investigated had retained the lipocalin fold. Corresponding thermal unfolding experiments confirmed similar folding stabilities, with melting temperatures ranging from 52.9 to 60.5°C (i.e., for the high-affinity variant).
Inhibition of human kallikreins 5 and 7 by the serine protease inhibitor lympho-epithelial Kazal-type inhibitor (LEKTI)
Authors: Schechter Norman M. , Choi Eun-Jung , Wang Zhe-Mei , Hanakawa Yasushi , Stanley John R. , Kang Ya'an , Clayman Gary L. , Jayakumar Arumugam 
Published: November 2005

AbstractLEKTI is a 120-kDa protein that plays an important role in skin development, as mutations affecting LEKTI synthesis underlie Netherton syndrome, an inherited skin disorder producing severe scaling. Its primary sequence indicates that the protein consists of 15 domains, all resembling a Kazal-type serine protease inhibitor. LEKTI and two serine proteases belonging to the human tissue kallikrein (hK) family (hK5 and hK7) are expressed in the granular layer of skin. In this study, we characterize the interaction of two recombinant LEKTI fragments containing three or four intact Kazal domains (domains 6–8 and 9–12) with recombinant rhK5, a trypsin-like protease, and recombinant rhK7, a chymotrypsin-like protease. Both fragments inhibited rhK5 similarly in binding and kinetic studies performed at pH 8.0, as well as pH 5.0, the pH of the stratum corneum where both LEKTI and proteases may function. Inhibition equilibrium constants (Ki) measured either directly in concentration-dependent studies or calculated from measured association (kass) and dissociation (kdis) rate constants were 1.2–5.5 nM at pH 8.0 and 10–20 nM at pH 5.0. At pH 8.0,kassandkdisvalues were 4.7×105 M−1s−1and 5.5×10−4 s−1, and at pH 5.0 they were 4.0×104 M−1 s−1and 4.3×10−4 s−1, respectively. The lowKiandkdisvalues (t1/2of 20–25 min) indicate tight and specific association. Only fragment 6–9′ was a good inhibitor of rhK7, demonstrating aKiof 11 nM at pH 8.0 in a reaction that was rapidly reversible. These results show that LEKTI, at least in fragment form, is a potent inhibitor of rhK5 and that this protease may be a target of LEKTI in human skin.
Applying the Proportional Hazard Premium Calculation Principle
Authors: Maria de Lourdes Centeno , João Andrade e Silva 
Published: November 2005

In this paper we discuss the application of the proportional hazard premium calculation principle.In Section 2 we propose a method to calculate the proportional hazard premium of a compound risk when the severity distribution is subexponential.In Section 3 we use the empirical distribution to calculate the premium when the proportional hazard principle is applied, which leads to a systematic underestimation of the premium. After studying the bias of the premium calculated using this non-parametric approach we take advantage of the bootstrap technique with subsampling to reduce it.
Controlled Electrodissolution of Polyelectrolyte Multilayers: A Platform Technology Towards the Surface‐Initiated Delivery of Drugs
Authors: Boulmedais F. , Tang C. S. , Keller B. , Vörös J. 
Published: November 2005

AbstractA novel method for the electrochemical dissolution of polyelectrolyte multilayers from the surface of an electrode for applications in controlled drug delivery is reported. Biodegradable and biocompatible multilayer films based on poly(L‐lysine) and heparin have been selected as a model system, and have been built on an indium tin oxide semiconductor substrate. The build‐up and dissolution processes of the multilayers is followed by electrochemical optical waveguide light mode spectroscopy. The formation and stability of the polyelectrolyte multilayers have been found to depend on the applied potential and the ionic strength of the buffer. The application of potentials above a threshold of 1.8 V induces dissolution, which follows single‐exponential kinetics, of the polyelectrolyte multilayer film. The rate of this process can be varied by an on–off profile of the potential, leading to the controlled release of heparin into the bulk. Atomic force microscopy investigations show that the electrodissolution of the polyelectrolyte multilayers is a local phenomenon that leads to the formation of nanoporous films.
Metal/Semiconductor Core/Shell Nanodisks and Nanotubes
Authors: Gao P. X. , Lao C. S. , Ding Y. , Wang Z. L. 
Published: November 2005

AbstractThe low melting point of Zn and the high melting point of ZnO, as well as their hexagonal crystal structures, present great advantages for designing and fabricating various metal/semiconductor core/shell nanostructures. By controlling the kinetics in the Zn and ZnO system, the lower‐energy facets, and the oxidation rates of different surfaces, we can control the fabrication of Zn/ZnO core/shell single‐crystal, polycrystalline, and mesoporous nanodisks, as well as a variety of ZnO nanotubes. The oxidation of a Zn nano‐object leads to the formation of Zn/ZnO core/shell nanodisks. A lower oxidation temperature results in the formation of a single‐crystal‐like Zn/ZnO core/shell structure, while a higher oxidation temperature leads to the formation of textured and even polycrystalline nanostructures. A re‐sublimation process of Zn in the core leaves a ZnO shell structure. This is an approach for synthesizing metal/semiconductor core/shell or composite nanostructures. This article offers a detailed description of the kinetics controlling the procedures, the nanostructures obtained, their morphological and crystal structures, and their formation mechanisms.
Superparamagnetic Polymer Nanocomposites with Uniform Fe3O4 Nanoparticle Dispersions
Authors: Gass J. , Poddar P. , Almand J. , Srinath S. , Srikanth H. 
Published: November 2005

AbstractMagnetic nanoparticles embedded in polymer matrices are good examples of functional nanostructures with excellent potential for applications such as electromagnetic interference shielding, magneto‐optical storage, biomedical sensing, flexible electronics, etc. Control over the dispersion of the nanoparticle phase embedded in a polymer matrix is critical and often challenging. To achieve excellent dispersion, competition between polymer–polymer and polymer–particle interactions have to be balanced to avoid clustering of particles in polymer nanocomposites. We report the first deposition of magnetic nanocomposite poly(methyl methacrylate)/polypyrrole bilayers from solution using spin‐coating. Fe3O4 nanoparticles have been synthesized using a chemical co‐precipitation route. Using a combination of dissolving the polymer and mixing fatty acid surfactant coated Fe3O4 nanoparticles, we have demonstrated the formation of nanocomposites with uniform nanoparticle dispersion. Cross‐sectional scanning electron microscopy, transmission electron microscopy, and magnetic measurements confirm the excellent dispersion and superparamagnetic response. Low‐frequency impedance measurements on these bilayers are also presented and analyzed.
Some New Developments in the Synthesis, Functionalization, and Utilization of Monodisperse Colloidal Spheres
Authors: Jeong U. , Wang Y. , Ibisate M. , Xia Y. 
Published: November 2005

AbstractThis article provides an overview of some recent developments related to the synthesis and functionalization of monodisperse colloidal spheres, a class of colloidal materials that has found widespread use in applications such as the fabrication of photonic crystals, optical sensing, and drug delivery. Traditionally, the choice of materials has been limited to polystyrene and silica. We and other groups have recently expanded the scope of materials by developing a number of methods for producing monodisperse colloidal spheres from various semiconductors and metals. This article is confined to our own work; it covers three different synthetic strategies: the bottom–up approach, the top–down approach, and template‐directed synthesis. The colloidal spheres may have a solid, hollow, or core–shell structure, and the chemical compositions can include Se, Bi, Pb, In, Sn, Cd, Pt, Ag2Se, CdSe, PbS, or TiO2. As an example to illustrate the attractive features of these colloidal spheres, we demonstrate the fabrication of Ag2Se‐based photonic crystals whose stop bands can be thermally switched between two spectral positions.
Role of mathematical modeling on the optimal control of HIV‐1 pathogenesis
Authors: Joly Marcel , Pinto Jose M. 
Published: November 2005

AbstractMathematical modeling of HIV‐1 infection has proven to be instrumental for the modern understanding basis of the AIDS pathogenesis, since it offers the unique means to adequately pose hypotheses concerning AIDS dynamics and treatment protocols. Focusing on the HIV‐1 subtype‐B epidemic, a comprehensive review and discussion of the state‐of‐the‐art in the area is presented. Based on recent results, this multidisciplinary study is then extended to a more in‐depth view at the cellular and molecular biology levels that address key issues concerned with the natural history of AIDS, as the basic human anatomic model, the host cell entry of HIV‐1, the quantification the HIV‐1 infectivity in terms of viral coreceptor specificity, as well as regulation and expression of CCR5 and CXCR4 molecules on the target cell, the T‐lymphocyte generation and infection models, and the immune response model. In the sequence, modeling techniques for AIDS pathogenesis are revised and models concerned with either the general HIV‐1 dynamics or specifically related to the HIV‐1 primary infection are discussed. Ultimately, a general framework for the real‐world problem of optimizing the highly active antiretroviral therapy (HAART) benefits is proposed regarding the important questions associated with the drug chemotherapy resistance, side effects and costs. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Atmosphärische Aerosole: Zusammensetzung, Transformation, Klima‐ und Gesundheitseffekte
Authors: Pöschl Ulrich 
Published: November 2005

AbstractAerosole sind von zentraler Bedeutung für Chemie und Physik der Atmosphäre sowie für Biosphäre, Klima und Gesundheit. Die luftgetragenen festen und flüssigen Partikel mit Größen im Nanometer‐ und Mikrometerbereich beeinflussen die Energiebilanz der Erde, den Wasserkreislauf und die atmosphärische Zirkulation, aber auch das Vorkommen von Treibhausgasen und reaktiven Spurengasen. Zudem spielen sie wichtige Rollen bei der Fortpflanzung biologischer Organismen und können Erkrankungen auslösen oder verstärken. Die grundlegenden Parameter, die die Umwelt‐ und Gesundheitseffekte von Aerosolpartikeln bestimmen, sind ihre Konzentration, Größe, Struktur und chemische Zusammensetzung. Diese Parameter sind jedoch örtlich und zeitlich hoch variabel. Insbesondere für biologische Partikel und kohlenstoffhaltige Feinstaubkomponenten ist nicht nur die Quantifizierung, sondern auch die Identifizierung eine anspruchsvolle analytische Aufgabe. Dieser Aufsatz umreißt den aktuellen Wissensstand und diskutiert offene Fragen und Forschungsperspektiven zu den Eigenschaften und Wechselwirkungen atmosphärischer Aerosole sowie zu ihren Auswirkungen auf das Klima und die menschliche Gesundheit.
Atmospheric Aerosols: Composition, Transformation, Climate and Health Effects
Authors: Pöschl Ulrich 
Published: November 2005

AbstractAerosols are of central importance for atmospheric chemistry and physics, the biosphere, climate, and public health. The airborne solid and liquid particles in the nanometer to micrometer size range influence the energy balance of the Earth, the hydrological cycle, atmospheric circulation, and the abundance of greenhouse and reactive trace gases. Moreover, they play important roles in the reproduction of biological organisms and can cause or enhance diseases. The primary parameters that determine the environmental and health effects of aerosol particles are their concentration, size, structure, and chemical composition. These parameters, however, are spatially and temporally highly variable. The quantification and identification of biological particles and carbonaceous components of fine particulate matter in the air (organic compounds and black or elemental carbon, respectively) represent demanding analytical challenges. This Review outlines the current state of knowledge, major open questions, and research perspectives on the properties and interactions of atmospheric aerosols and their effects on climate and human health.
Reactions of [Ru(CO)3Cl2]2with aromatic nitrogen donor ligands in alcoholic media
Authors: Moreno M. Andreina , Haukka Matti , Kallinen Mirja , Pakkanen Tapani A. 
Published: November 2005

AbstractThe reactions of mono‐ and bidentate aromatic nitrogen‐containing ligands with [Ru(CO)3Cl2]2in alcohols have been studied. In alcoholic media the nitrogen ligands act as bases promoting acidic behaviour of alcohols and the formation of alkoxy carbonyls [Ru(N–N)(CO)2Cl(COOR)] and [Ru(N)2(CO)2Cl(COOR)]. Other products are monomers of type [Ru(N)(CO)3Cl2], bridged complexes such as [Ru(CO)3Cl2]2(N), and ion pairs of the type [Ru(CO)3Cl3]−[Ru(N–N)(CO)3Cl]+(N–N = chelating aromatic nitrogen ligand, N = non‐chelating or bridging ligand). The reaction and the product distribution can be controlled by adjusting the reaction stoichiometry. The reactivity of the new ruthenium complexes was tested in 1‐hexene hydroformylation. The activity can be associated with the degree of stability of the complexes and the ruthenium–ligand interaction. Chelating or bridging nitrogen ligands suppresses the activity strongly compared with the bare ruthenium carbonyl chloride, while the decrease in activity is less pronounced with monodentate ligands. A plausible catalytic cycle is proposed and discussed in terms of ligand–ruthenium interactions. The reactivity of the ligands as well as the catalytic cycle was studied in detail using the computational DFT methods. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of Fe‐loaded MFI zeolite using silatrane as precursor and its CO activity
Authors: Kritchayanon N. , Thanabodeekij N. , Jitkarnka S. , Jamieson A. M. , Wongkasemjit S. 
Published: November 2005

AbstractFe‐MFI zeolite was successfully synthesized using silatrane as precursor and tetrapropyl ammonium bromide as template via the sol–gel process and microwave heating technique. The effects of ageing time, heating temperature, heating time and iron concentration were investigated, and it was found that Fe‐MFI synthesis favors higher heating temperatures, but is limited by the degradation of the incorporation of a template molecule. Moreover, longer ageing and heating times promote the incorporation of higher amounts of iron atom in the MFI structure. However, too long an ageing time decreases the incorporation of iron. The lower the percentage Fe loading, the greater the percentage of Fe3+ ions incorporated into the MFI framework. The catalytic activity of Fe‐MFI catalyst for the oxidation of CO was studied and it was found that these synthesized catalysts catalyzed the oxidation of CO very well. Copyright © 2005 John Wiley & Sons, Ltd.
Preparation, characterization and biological studies of some novel ferrocenyl compounds
Authors: Abd‐Elzaher Mokhles M. , Ali Ibrahim A. I. 
Published: November 2005

AbstractReaction of ferrocene with trichloroacetimidates in the presence of TMSOTf as a catalyst gave a series of novel ferrocenyl compounds, 1–7, in good yield and by a simple method using the Friedel–Crafts reaction. Only monosubstituted ferrocenyl compounds were obtained by flash chromatography at room temperature. Attempts to separate the disubstituted ferrocenyl compounds were unsuccessful, even in the presence of excess (2:1, 3:1 or 4:1) of trichloroacetimidates. The prepared compounds have been characterized by 1H NMR, 13C NMR, IR, UV–vis and mass spectra as well as elemental analysis. The prepared compounds showed medium to good antimicrobial activity against Bacillus subtilis (+ve), Staphylococcus aureus (+ve), Candida albicans (yeast), Escherichia coli (−ve), Salmonella typhi (−ve), Aspergillus niger (fungi) and Fusarium solani (fungi). Copyright © 2005 John Wiley & Sons, Ltd.
1‐Silacyclopent‐2‐enes and 1‐silacyclohex‐2‐enes bearing functionally substituted silyl groups in 2‐positions. Novel electron‐deficient SiHB bridges
Authors: Wrackmeyer Bernd , Tok Oleg L. , Milius Wolfgang , Khan Azim , Badshah Amin 
Published: November 2005

AbstractThe reactions of alkyn‐1‐yl(vinyl)silanes R2Si[CC‐Si(H)Me2]CHCH2 [R = Me (1a), Ph (1b)], Me2Si[CC‐Si(Br)Me2]CHCH2 (2a), and of alkyn‐1‐yl(allyl)silanes R2Si[CC‐Si(H)Me2]CH2CHCH2 (R = Me (3a), R = Ph (3b)] with 9‐borabicyclo[3.3.1]nonane in a 1:1 ratio afford in high yield the 1‐silacyclopent‐2‐ene derivatives 4a, b and 5a, and the 1‐silacyclohex‐2‐ene derivatives 6a, b, respectively, all of which bear a functionally substituted silyl group in 2‐position and the boryl group in 3‐position. This is the result of selective intermolecular 1,2‐hydroboration of the vinyl or allyl group, followed by intramolecular 1,1‐organoboration of the alkynyl group. In the cases of 4a, b, potential electron‐deficient SiHB bridges are absent or extremely weak, whereas in 6a,b the existence of SiHB bridges is evident from the NMR spectroscopic data (1H, 11B, 13C and 29Si NMR). The molecular structure of 4b was determined by X‐ray analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Some principles of regeneration in mammalian systems
Authors: Carlson Bruce M. 
Published: November 2005

AbstractThis article presents some general principles underlying regenerative phenomena in vertebrates, starting with the epimorphic regeneration of the amphibian limb and continuing with tissue and organ regeneration in mammals. Epimorphic regeneration following limb amputation involves wound healing, followed shortly by a phase of dedifferentiation that leads to the formation of a regeneration blastema. Up to the point of blastema formation, dedifferentiation is guided by unique regenerative pathways, but the overall developmental controls underlying limb formation from the blastema generally recapitulate those of embryonic limb development. Damaged mammalian tissues do not form a blastema. At the cellular level, differentiation follows a pattern close to that seen in the embryo, but at the level of the tissue and organ, regeneration is strongly influenced by conditions inherent in the local environment. In some mammalian systems, such as the liver, parenchymal cells contribute progeny to the regenerate. In others, e.g., skeletal muscle and bone, tissue‐specific progenitor cells constitute the main source of regenerating cells. The substrate on which regeneration occurs plays a very important role in determining the course of regeneration. Epimorphic regeneration usually produces an exact replica of the structure that was lost, but in mammalian tissue regeneration the form of the regenerate is largely determined by the mechanical environment acting on the regenerating tissue, and it is normally an imperfect replica of the original. In organ hypertophy, such as that occurring after hepatic resection, the remaining liver mass enlarges, but there is no attempt to restore the original form. Anat Rec (Part B: New Anat) 287B:4–13, 2005. © 2005 Wiley‐Liss, Inc.