bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model Neuronowy Ekstraktora Obrazów Sygnałów Radiolokacyjnych
Authors: Krukar Wojciech , Niedziela Tadeusz 
Published: March 2009

Model Neuronowy Ekstraktora Obrazów Sygnałów RadiolokacyjnychPrzeprowadzono badania symulacyjne programowego modelu ekstraktora neuronowego, który realizuje detekcję obiektu oraz określa jego położenie na tle szumu. Do symulacji sygnału radiolokacyjnego użyty został model sygnału, który jest sumą dwóch niezależnych procesów: sygnału odbitego od obiektu oraz szumu. Model ten uwzględnia impulsowe sondowanie, charakterystykę promieniowania obracającej się anteny, fluktuację powierzchni skutecznej obiektu oraz dopplerowskie przesunięcie częstotliwości nośnej. Do badań porównawczych przyjęto model ekstraktora powierzchniowego oraz powierzchniowo-amplitudowego. W wyniku zebranych doświadczeń podczas pracy projektowej do zadań postawionych ekstraktorowi neuronowemu najlepszą strukturą sieci okazała się trójwarstwowa sieć uczona metodą wstecznej propagacji błędu, posiadająca dwie warstwy ukryte, z tangensoidalną funkcją aktywacji oraz ruchomym progiem.
Semiconducting Thienothiophene Copolymers: Design, Synthesis, Morphology, and Performance in Thin‐Film Organic Transistors
Authors: McCulloch Iain , Heeney Martin , Chabinyc Michael L. , DeLongchamp Dean , Kline R. Joseph , Cölle Michael , Duffy Warren , Fischer Daniel , Gundlach David , Hamadani Behrang , Hamilton Rick , Richter Lee , Salleo Alberto , Shkunov Maxim , Sparrowe David , Tierney Steven , Zhang Weimin 
Published: March 2009

AbstractOrganic semiconductors are emerging as a viable alternative to amorphous silicon in a range of thin‐film transistor devices. With the possibility to formulate these p‐type materials as inks and subsequently print into patterned devices, organic‐based transistors offer significant commercial advantages for manufacture, with initial applications such as low performance displays and simple logic being envisaged. Previous limitations of both air stability and electrical performance are now being overcome with a range of both small molecule and polymer‐based solution‐processable materials, which achieve charge carrier mobilities in excess of 0.5 cm2 V−1 s−1, a benchmark value for amorphous silicon semiconductors. Polymer semiconductors based on thienothiophene copolymers have achieved amongst the highest charge carrier mobilities in solution‐processed transistor devices. In this Progress Report, we evaluate the advances and limitations of this class of polymer in transistor devices.
Nanostructured Organic–Inorganic Composite Materials by Twin Polymerization of Hybrid Monomers
Authors: Spange Stefan , Grund Silke 
Published: March 2009

AbstractForming two structurally different but associated polymer structures in a single step is a possible route for the production of nanostructured materials. By means of twin polymerization of specially constructed monomers consisting of two different covalently bonded building blocks (hybrid monomers), this route is realized. What is important is that two different macromolecular structures are formed from one monomer in a single process. The two polymers formed can be linear, branched, or cross‐linked structures. The molecular composition of the hybrid monomer defines the degree of cross‐linking of the corresponding macromolecular structures that is theoretically possible.
Enantioselective Reduction of Diaryl Ketones Catalyzed by a Carbonyl Reductase from Sporobolomyces salmonicolor and its Mutant Enzymes
Authors: Li Hongmei , Zhu Dunming , Hua Ling , Biehl Edward R. 
Published: March 2009

Abstractmagnified imageThe carbonyl reductase from red yeast Sporobolomyces salmonicolor AKU4429 (SSCR) and its mutant enzymes effectively catalyzed the enantioselective reduction of diaryl ketones to give the corresponding chiral alcohols. Both conversion and enantioselectivity were dependent on the co‐solvent in the reaction medium. Diaryl ketones with a para‐substituent on one of the phenyl groups were reduced with high enantioselectivity (up to 99% ee), which is difficult to achieve using chemical methods such as chiral borane reduction, asymmetric hydrogenation or hydrosilylation. Mutation of SSCR at Q245 resulted in a higher amount of (S)‐enantiomer in the products, and in the case of mutant Q245P with para‐substituted diaryl ketones as substrate, this effect was so remarkable that the reduction enantiopreference was switched from (R) to (S). The present study provides valuable information about the catalytic properties of the carbonyl reductase SSCR toward the reduction of diaryl ketones, serving as basis for further engineering of this enzyme to develop efficient biocatalysts for highly enantiospecific reduction of diaryl ketones without high electronic dissymmetry or an ortho‐substituent on one of the aryl groups.
Interfacing Glycosylated Carbon‐Nanotube‐Network Devices with Living Cells to Detect Dynamic Secretion of Biomolecules
Authors: Sudibya Herry Gunadi , Ma Jimei , Dong Xiaochen , Ng Simon , Li Lain‐Jong , Liu Xue‐Wei , Chen Peng 
Published: March 2009

AbstractSanfte Zellanalytik: Zum Einsatz als Biosensoren wurden einwandige Kohlenstoffnanoröhren (SWNTs) mit bioaktiven Monosacchariden funktionalisiert. Ein bioverträgliches glycosyliertes Netzwerk aus Nanoröhren kann lebende Zellen anlagern (siehe Schema) und die Ausschüttung von Biomolekülen auf elektronischem Weg mit hoher zeitlicher Präzision und Empfindlichkeit wiedergeben.magnified image
Symmetry versus Minimal Pentagonal Adjacencies in Uranium‐Based Polyoxometalate Fullerene Topologies
Authors: Sigmon Ginger E. , Unruh Daniel K. , Ling Jie , Weaver Brittany , Ward Matthew , Pressprich Laura , Simonetti Antonio , Burns Peter C. 
Published: March 2009

AbstractWahl der Nachbarn: Cluster mit 60, 44 und 36 Uranylperoxidhydroxid‐Polyedern (siehe Bild) nehmen Fullerentopologien von maximaler Symmetrie an. Der größte Cluster, U60, ist topologisch identisch mit C60 (keine benachbarten Fünfecke, höchstmögliche Symmetrie). U44 hat eine Topologie mit maximaler Symmetrie anstelle einer Topologie mit der niedrigsten Zahl benachbarter Fünfecke.magnified image
Presence of Galanin‐Like Immunoreactivity in Mesenchymal and Neural Crest Origin Tissues During Embryonic Development in the Mouse
Authors: Jones Melissa , Perumal Paul , Vrontakis Maria 
Published: March 2009

AbstractGalanin is a highly conserved neuropeptide with a wide range of biological effects. Recently, through transcriptome analysis, galanin was identified in undifferentiated mouse embryonic stem cells as one of the most abundant transcripts. We have examined the developmental expression of galanin‐like immunoreactivity in mice from embryonic day 10 (E10) to embryonic day 15 (E15). At E10, galanin was readily detected in the undifferentiated head and trunk mesenchyme of both mesodermal and neural crest origin. There was also strong immunoreactivity in the mesenchymal spiral ridges of the outflow tract of the heart and the endocardial cushions. The highest level of galanin detected was at E13 in the craniofacial mesenchyme and proliferating chondrocytes in bones of both neural crest and mesoderm origin. Dorsal root ganglia and trigeminal ganglia contained galanin immunoreactive cells as well. These data indicate the presence of galanin peptide during periods of morphogenesis and thus a developmental role for the peptide in mesenchymal and neural crest origin tissues in the mouse embryo. Whether galanin has a growth and/or differentiating role, still remains to be demonstrated. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Protein feeds coproduction in biomass conversion to fuels and chemicals
Authors: Dale Bruce E. , Allen Michael S. , Laser Mark , Lynd Lee R. 
Published: March 2009

AbstractAgriculture has changed greatly in the past in response to changing human needs. Now agriculture is being called on to provide raw materials for very large‐scale fuel and chemical production. Agriculture will change again in response to this demand and all producers and users of agricultural feedstocks will be affected by this change. For example, livestock feeding practices have already changed in response to the availability of distillers' grains from corn ethanol production. A fuels industry based on herbaceous biomass energy crops will be many‐fold larger than the existing corn ethanol industry and will produce its own set of impacts on livestock feeding. We explore here one of these impacts: the availability of large new sources of feed protein from biomass energy crops.In addition to structural carbohydrates, such as cellulose and hemicellulose, herbaceous biomass energy crops can easily be produced with approximately 10% protein, called ‘leaf protein’. This leaf protein, as exemplified by alfalfa leaf protein, is superior to soybean meal (SBM) protein in its biological value. Leaf protein recovery and processing fit well into many process flow diagrams for biomass fuels. When leaf protein is properly processed to concentrate it and remove antinutritional factors, as we have learned over the years to do with soybean meal protein, protein in leaf protein concentrate (LPC) will probably be at least as valuable in livestock diets as SBM protein.If LPC is used to meet 20% of total animal protein requirements (i.e., market penetration of 20%) then the potential utilization of leaf protein concentrate could reach as much as 24 million metric tons annually. This leaf protein will replace protein from SBM and other sources. This much leaf protein will reduce by approximately 16 million hectares the amount of land required to provide protein for livestock. Likewise the amount of land required to meet fuel needs will effectively be reduced by 8 million hectares because this land will effectively do ‘double duty’ by producing needed animal protein as well as feedstocks for fuel production. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Coproduction of ethanol and power from switchgrass
Authors: Laser Mark , Jin Haiming , Jayawardhana Kemantha , Lynd Lee R. 
Published: March 2009

AbstractThree process designs for producing ethanol and electricity from switchgrass are evaluated: a base‐case technology scenario involving dilute acid pre‐treatment and simultaneous saccharification and fermentation, and two mature technology scenarios incorporating ammonia fiber expansion pre‐treatment and consolidated bioprocessing – one with conventional Rankine power coproduction, and one coproducing power via a gas turbine combined cycle. Material and energy balances – resulting from detailed Aspen Plus models – are reported and used to estimate processing costs and perform discounted cash flow analysis to assess plant profitability. The mature technology —designs significantly improve both process efficiency and cost relative to base‐case cellulosic ethanol technology, with the resulting fossil fuel displacement being decidedly positive and production costs competitive with gasoline, even at relatively low prices. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparison of the structural and functional properties of RNase A and BS‐RNase: A stepwise mutagenesis approach
Authors: Ercole Carmine , Colamarino Rosa Angela , Pizzo Elio , Fogolari Federico , Spadaccini Roberta , Picone Delia 
Published: March 2009

AbstractThe original structure of bovine seminal ribonuclease (BS‐RNase), solved in 1993, represents a milestone in the story of protein structure, because it represented the first X‐ray structure showing two polypeptide chains entangled through their terminal regions. It is generally assumed that this structural feature is the basis of several special biological activities, including a potent antitumor activity, but this has not been yet definitely proved. To assess this hypothesis, in this article we have analyzed the effects of the N‐terminal hinge region and/or of Arg80 on the swapping propensity and cytotoxicity in newly designed proteins, using a covalent dimeric variant of bovine pancreatic ribonuclease (RNase A) as scaffold. All the proteins have a very poor cytotoxic activity, independently on the swapping propensity, that can even reach the same value of native BS‐RNase. Overall our data suggest that the swapping represents still an essential requisite for the cytotoxic activity, because it keeps the dimeric structure stable even in the reducing cytosolic environment, but other features are essential to design dimeric antitumor ribonucleases, including a strong positive potential at the N‐terminal face and a quaternary structure able to evade the cytosolic ribonuclease inhibitor, with or without the interchain disulfide bridges. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1009–1017, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Terminal sidechain packing of a designed β‐hairpin influences conformation and stability
Authors: Eidenschink Lisa , Crabbe Edward , Andersen Niels H. 
Published: March 2009

AbstractWhile end capping in α‐helices is well understood, the concept of capping a β‐hairpin is a relatively recent development; to date, favorable Coulombic interactions are the only example of sidechains at the termini influencing the overall stability of a β‐hairpin. While cross‐strand hydrophobic residues generally provide hairpin stabilization, particular when flanking the turn region, those remote from this location appear to provide little stabilization. While probing for an optimal residue at a hydrogen bond position near the terminus of a designed β‐hairpin a conservative, hydrophobic, V → I mutation was observed to not only result in a significant change in fold population but also effected major changes in the structuring shifts at numerous sites in the peptide. Mutational studies reveal that there is an interaction between the sidechain at this H‐bonded site and the sidechain at the C‐terminal non‐H‐bonded site of the hairpin. This interaction, which appears to be hydrophobic in character, requires a highly twisted hairpin structure. Modifications at the C‐terminal site, for example an E → A mutation (ΔΔGU = 6 kJ/mol), have profound affects on fold structure and stability. The data suggests that this may be a case of hairpin end capping by the formation of a hydrophobic cluster. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 557–564, 2009.This article was originally published online as an accepted preprint. The “Published Online”date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Electrochemical and Conformational Consequences of Copper (CuI and CuII) Binding to β‐Amyloid(1–40)
Authors: Brzyska Maria , Trzesniewska Katarzyna , Wieckowska Agnieszka , Szczepankiewicz Andrzej , Elbaum Danek 
Published: March 2009

AbstractCopper‐induced structural rearrangements of Aβ40 structure and its redox properties are described in this study. Electrochemical and fluorescent methods are used to characterise the behaviour of Aβ–Cu species. The data suggest that time‐dependent folding of Aβ–Cu species may cause changes in the redox potentials.magnified imageExtracellular deposits of β‐amyloid (Aβ) into senile plaques are the major features observed in brains of Alzheimer's disease (AD) patients. A high concentration of copper has been associated with insoluble amyloid plaques. It is known that Aβ(1–40) can bind copper with high affinity, but electrochemical properties of Aβ(1–40)–Cu complexes are not well‐characterised. In this study we demonstrate that complexation of copper (both as CuI and CuII) by Aβ(1–40) reduces the metal electrochemical activity. Formation of copper‐Aβ(1–40) complexes is associated with alteration of the redox potential. The data reveal significant redox activity of fresh Aβ–copper solutions. However, copper‐induced structural rearrangements of the peptide, documented by CD, correspond with time‐dependent changes of formal reduction potentials (E0′) of the complex. Fluorescent and electrochemical (cyclic voltammetry and differential pulse voltammetry) techniques suggest that reduction of the redox activity by Aβ–Cu complexes could be attributed to conformational changes that diminished copper accessibility to the external environment. According to our evidence, conformational rearrangements, induced by copper binding to amyloid, elongate the time necessary to attain the same β‐sheet content as for the metal‐free peptide. Although the redox activity of Aβ–Cu complexes diminishes in a time‐dependent manner, they are not completely devoid of toxicity as they destabilize red blood cells osmotic fragility, even after prolonged incubation.
Enantioselective Synthesis of 2‐Isoxazolines by a One‐Flask Conjugate Addition/Oxime‐Transfer Process
Authors: Pohjakallio Antti , Pihko Petri M. 
Published: March 2009

AbstractEnantioselective isoxazoline synthesis: A combination of 1) a catalytic enantioselective conjugate addition of oximes to α,β‐unsaturated aldehydes and 2) an acid‐catalyzed intramolecular oxime‐transfer reaction lead to the first asymmetric synthesis of 3‐unsubstituted 2‐isoxazolines (see scheme).magnified image
Cellular expression of Midkine‐a and Midkine‐b during retinal development and photoreceptor regeneration in zebrafish
Authors: Calinescu Anda‐Alexandra , Vihtelic Thomas S. , Hyde David R. , Hitchcock Peter F. 
Published: March 2009

AbstractIn the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Müller glia. Recently, Müller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine‐b (mdkb). Midkine is a highly conserved heparin‐binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors, and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are coexpressed in horizontal cells and proliferating Müller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration. J. Comp. Neurol. 514:1–10, 2009. © 2009 Wiley‐Liss, Inc.
One‐Pot, Selective Hydroformylation, Condensation, and Hydrogenation Processes by a Sol–Gel Entrapped Rhodium Complex, an Immobilized Base, and an Ionic Liquid
Authors: Hamza Khalil , Schumann Herbert , Blum Jochanan 
Published: March 2009

AbstractWe report on a one‐pot, multistep process in which styrene derivatives are selectively hydroformylated to give branched aldehydes, which in turn, are condensed with reactive methylene compounds (malononitrile, ethyl cyanoacetate), and then hydrogenated. The process takes place at 80 °C under 20.7 bar H2 and 20.7 bar CO in the presence of [Rh(cod)Cl]2 and Na[Ph2P‐3‐(C6H4SO3)], which have been co‐entrapped within ionic liquid confined silica sol–gel together with a separately encaged base. The catalyst can be reused at least four times, but the base has to be renewed after each run. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Prejudice in the police: On the processes underlying the effects of selection and group socialisation
Authors: Gatto Juliette , Dambrun Michaël , Kerbrat Christian , De Oliveira Pierre 
Published: March 2009

AbstractThe principal aim of this study is to determine why police officers are generally found to be more prejudiced towards disadvantaged groups than are the standard population. Two independent processes were expected to account for this effect: Selection and group socialisation. Using a cross‐sectional design (N = 170), firstly, we compared, newly recruited police officers with a control population (selection effect), and secondly, police officers with 1 year of training with the newly recruited ones (group socialisation effect). Results reveal a significant effect of both selection and group socialisation, the two being underlined by distinct processes; right‐wing authoritarianism (RWA) in the case of the former and internalisation of a prejudice norm in the case of the latter. Finally, the results show that group identification moderates the change in internalisation of the prejudice norm. Copyright © 2009 John Wiley & Sons, Ltd.
Adjustments in channel form, sediment calibre and vegetation around check‐dams in the headwater reaches of mountain torrents, Calabria, Italy
Authors: Bombino G. , Gurnell A. M. , Tamburino V. , Zema D. A. , Zimbone S. M. 
Published: March 2009

AbstractThe structure and dynamics of vegetation in valley bottoms are both strongly associated with fluvial processes and landform dynamics. All of these associations are disrupted by the installation of engineering control works. We use survey and analysis methods developed previously to investigate the impact of the installation of check‐dams within the confined headwaters of steep seasonally‐flowing streams (fiumaras) in Calabria, southern Italy, on active channel form, sediment calibre, and the richness, cover and development of riparian vegetation. Based on detailed field measurements along transects across the active channel, estimates of indices of vegetation extent (GCC), development (WCH) and their cross‐sectional variability (coefficients of variation of both indices at each survey site CVGCC, CVWCH), the number of species present (Ns), channel shape (w/d – the width/depth ratio), cross‐sectional area (CSA), downstream gradient (slope), surface bed sediment calibre (D50) and subsurface fine sediment content (percentage less than 250 µm by weight) were obtained for 60 transects located immediately upstream (U), downstream (D) and at intermediate sites (I) around 20 check‐dams located in four different headwater catchments. Analysis of this data set suggests that statistically significant changes in channel form and sediment calibre upstream of check‐dams are associated with more consistent vegetation development across the active channel, including an increase in species richness relative to other transects, but notable increases in vegetation cover and development only arise where the physical characteristics of the channel are notably different from intermediate and downstream channels. Because of the naturally steep profile of the study torrents, intermediate sections between check‐dams tend to be more similar in form to channels located immediately downstream of check‐dams than those located upstream, leading to similar structural properties in the riparian vegetation. The intermediate transects support considerably more species than downstream reaches, but the conditions upstream of the check‐dams appear to be so favourable for riparian vegetation development that species richness exceeds that found in intermediate reaches. Despite the confined headwater locations, these contrasts in form, sediment and vegetation development around check‐dams are strong and consistent across the study catchments, over‐riding more subtle contrasts in species richness and sediment calibre between catchments. Copyright © 2009 John Wiley & Sons, Ltd.