bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of ω‐amino‐α‐phenylcarbonate alkanes and their polymerization to [n]‐polyurethanes
Authors: Arce Silvina M , Kolender Adriana A , Varela Oscar 
Published: May 2010

AbstractAliphatic [n]‐polyurethanes have recently been synthesized from ω‐isocyanato‐α‐alkanols or, more traditionally, by cationic ring‐opening polymerization of cyclourethanes or by the Bu2Sn(OMe)2‐promoted polycondensation of ω‐hydroxy‐α‐O‐phenylurethane alkanes. For the latter procedures, the conditions employed do not seem to be suitable for highly functionalized monomers. In contrast, the polymerization of ω‐amino‐α‐phenylcarbonate alkanes is expected to occur under milder conditions. ω‐Amino‐α‐phenylcarbonate alkanes have been synthesized from 6‐aminohexanol (1) and 3‐aminopropanol (6). The procedure involves the N‐Boc protection of the amino group, followed by activation of the alcohol. Removal of the N‐Boc affords the corresponding ω‐amino‐1‐O‐phenyloxycarbonyloxyalkane hydrochlorides. Other oligomeric comonomers between 1 and 6 have been prepared. The polymerization of these precursors takes place in the absence of metal catalysts to afford the corresponding linear and regioregular [n]‐polyurethanes. The procedure described is useful for the preparation of stable ω‐amino‐α‐phenylcarbonate alkane derivatives, which possess varied chain lengths between the terminal functions. These monomers yield [n]‐polyurethanes having various structures starting from just two aminoalkanols. The polyurethanes were obtained in high yields, with reasonable molecular weight and polydispersity values, and they were characterized spectroscopically and thermally. These studies reveal constitutionally uniform structures that are free of carbonate or urea linkages. Copyright © 2010 Society of Chemical Industry
Structure of the dimerization domain of DiGeorge Critical Region 8
Authors: Senturia Rachel , Faller Michael , Yin Sheng , Loo Joseph A. , Cascio Duilio , Sawaya Michael R. , Hwang Daniel , Clubb Robert T. , Guo Feng 
Published: May 2010

AbstractMaturation of microRNAs (miRNAs, ∼22nt) from long primary transcripts [primary miRNAs (pri‐miRNAs)] is regulated during development and is altered in diseases such as cancer. The first processing step is a cleavage mediated by the Microprocessor complex containing the Drosha nuclease and the RNA‐binding protein DiGeorge critical region 8 (DGCR8). We previously reported that dimeric DGCR8 binds heme and that the heme‐bound DGCR8 is more active than the heme‐free form. Here, we identified a conserved dimerization domain in DGCR8. Our crystal structure of this domain (residues 298–352) at 1.7 Å resolution demonstrates a previously unknown use of a WW motif as a platform for extensive dimerization interactions. The dimerization domain of DGCR8 is embedded in an independently folded heme‐binding domain and directly contributes to association with heme. Heme‐binding‐deficient DGCR8 mutants have reduced pri‐miRNA processing activity in vitro. Our study provides structural and biochemical bases for understanding how dimerization and heme binding of DGCR8 may contribute to regulation of miRNA biogenesis.
Structural characterization of a new statherin from pig parotid granules
Authors: Manconi Barbara , Fanali Chiara , Cabras Tiziana , Inzitari Rosanna , Patamia Maria , Scarano Emanuele , Fiorita Antonella , Vitali Alberto , Castagnola Massimo , Messana Irene , Teresa Sanna Maria 
Published: May 2010

AbstractThis study describes the identification and structural characterization of Sus scrofa statherin. HPLC–electrospray ionization mass spectrometry analysis on pig parotid secretory granule extracts evidenced a peptide with a molecular mass value of 5381.1 ± 0.6 Da and its truncated form, devoid of the C‐terminal Ala residue, with a molecular mass value of 5310.1 ± 0.6 Da. The complete sequence of pig statherin gene was determined by sequencing the full‐length cDNA obtained by rapid amplification of cDNA ends. The gene is 549 base pairs long and contains an open reading frame of 185 nucleotides, encoding a 42‐amino acid secretory polypeptide with a signal peptide of 19 residues. This sequence presents some typical features of the four statherins characterized till now, showing the highest degree of amino acid identity with bovine (57%) and human statherin (39%). Pig statherin is mono‐phoshorylated on Ser‐3, while primate statherins already characterized are di‐phosphorylated on Ser‐2 and Ser‐3. This difference, probably connected to the Asp‐4 → Glu substitution, suggests the involvement of the Golgi‐casein kinase, which strictly recognizes the SX(E/pS) consensus sequence. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Double helix formation in α‐peptides: a theoretical study
Authors: Schramm Peter , Hofmann Hans‐Jörg 
Published: May 2010

AbstractA complete overview on all possible hydrogen bonding patterns of double helices with antiparallel and parallel strand orientation in α‐peptide sequences is provided on the basis of ab initio molecular orbital theory. The most stable representatives belong to the group of antiparallel helices. The study on side chain influence shows that these double helices can only be realized if the strands are composed of L‐ and D‐amino acids in alternate order. The stability of the double helices is compared with that of competing single‐stranded helices. The data contribute to an understanding of secondary structure formation in peptides and provide a basis for a rational design of membrane channels. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
A study to assess the cross‐reactivity of cellulose membrane‐bound peptides with detection systems: an analysis at the amino acid level
Authors: Mahrenholz Carsten C. , Tapia Victor , Stigler Rolf D. , Volkmer Rudolf 
Published: May 2010

AbstractThe growing demand for binding assays to study protein–protein interaction can be addressed by peptide array‐based methods. The SPOT technique is a widespread peptide‐array technology, which is able to distinguish semi‐quantitatively the binding affinities of peptides to defined protein targets within one array. The quality of an assay system used for probing peptide arrays depends on the well‐balanced combination of screening and read‐out methods. The former address the steady‐state of analyte capture, whereas the latter provide the means to detect captured analyte. In all cases, however, false‐positive results can occur when challenging a peptide array with analyte or detecting captured analyte with label conjugates. Little is known about the cross‐reactivity of peptides with the detection agents. Here, we describe at the amino acid level the potential of (i) 5‐(and 6)‐carboxytetramethylrhodamine (5(6)‐TAMRA), (ii) fluoresceinisothiocyanate in form of the peptide‐bound fluorescein‐substituted thiourea derivative (FITC), and (iii) biotin/streptavidin‐POD to cross‐react with individual amino acids in a peptide sequence. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Tetrapeptides, as small‐sized peptidic inhibitors; synthesis and their inhibitory activity against BACE1
Authors: Kakizawa Taeko , Hidaka Koushi , Hamada Daisuke , Yamaguchi Ryoji , Uemura Tsuyoshi , Kitamura Hitomi , Tagad Harichandra D. , Hamada Takashi , Ziora Zyta , Hamada Yoshio , Kimura Tooru , Kiso Yoshiaki 
Published: May 2010

Abstractβ‐Site amyloid precursor protein cleaving enzyme 1 (BACE1) is known to be involved in the production of amyloid β‐peptide in Alzheimer's disease and is a major target for current drug design. We previously reported substrate‐based peptidomimetics, KMI‐compounds as potent BACE1 inhibitors. In this study, we designed and synthesized tetrapeptides as low molecular‐sized inhibitors. These exhibited high potency against recombinant BACE1, with the highest IC50 value of 34.6 nM from KMI‐927. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Influence of packaging design on littering and waste behaviour
Authors: Wever R. , van Onselen L. , Silvester S. , Boks C. 
Published: May 2010

AbstractLittering is a packaging‐related problem where the environmental, social and economic aspects of sustainability meet. Litter is likely to be harmful for wildlife, looks untidy and is expensive to clean up. Research into reducing litter has focused primarily on the litterer and on the surroundings in which the littering occurs, but the influence of the littered object has so far been ill addressed. This research focused on understanding how the characteristics of an object influence its probability of being littered and how this insight can be used to improve the design of these objects, in particular packaging. Both eco‐feedback and scripting approaches were examined in four experimental setups. It was found that the design of a packaging does have a significant influence on waste behaviour of consumers. However, applying this insight to packaging design in order to reduce littering was found to be less than straightforward. Copyright © 2010 John Wiley & Sons, Ltd.
Altitudinal trends of leaf δ13C follow different patterns across a mountainous terrain in north China characterized by a temperate semi‐humid climate
Authors: Wang Guoan , Zhou Liping , Liu Min , Han Jiamao , Guo Jingheng , Faiia Anthony , Su Fang 
Published: May 2010

AbstractMany studies have documented that the δ13C values of plants increase with altitude both on a global scale and locally in humid climates, while in semi‐arid areas the opposite trend has been found. The study reported herein was conducted in a mountainous area of China characterized by a temperate semi‐humid climate. The δ13C values of C3 species do not exhibit a consistent variation along an altitudinal gradient and the observations suggest that the pattern of increasing δ13C with altitude cannot be generalized. In the study area, in addition to environmental factors such as changing air pressure and light, the interaction between temperature and plant water balance determines the δ13C‐altitude variations in C3 plants. The δ13C of the leaves of C4 plants is found to increase with altitude with a mean gradient of 0.9‰/km. The altitudinal trend of C4 plants is attributed to the combined influences of water availability and other factors rather than temperature. Copyright © 2010 John Wiley & Sons, Ltd.
The distinguishing features of human metapneumovirus and respiratory syncytial virus
Authors: Papenburg Jesse , Boivin Guy 
Published: May 2010

AbstractAcute respiratory tract infections (RTIs) are a leading cause of morbidity and mortality worldwide. Human Metapneumovirus (hMPV) is a member of the Metapneumovirus genus within the Pneumovirinae subfamily of the Paramyxoviridae family. Though hMPV was only discovered in 2001, a large body of work has already shown that it is the aetiologic agent of a substantial proportion of upper and lower RTIs across all age groups in both healthy and immunocompromised hosts throughout the world. RSV, also a pneumovirus, is the human pathogen most closely related to hMPV. RSV is the leading cause of pneumonia and bronchiolitis in infants and young children, but can also cause respiratory tract disease in all age groups. In this paper, we will review the salient features of the virology, epidemiology, pathogenesis, host immune responses, clinical manifestations and diagnostic modalities of hMPV, using RSV as a comparison. In addition, we will show how immunoprophylactic and therapeutic strategies studied and used in clinical practice for RSV—some with great success, and others tragic failure—have led to promising areas of research for the prevention and treatment of the significant burden of disease caused by hMPV. Copyright © 2010 John Wiley & Sons, Ltd.
Novel insights into proteolytic cleavage of influenza virus hemagglutinin
Authors: Bertram Stephanie , Glowacka Ilona , Steffen Imke , Kühl Annika , Pöhlmann Stefan 
Published: May 2010

AbstractThe influenza virus hemagglutinin (HA) mediates the first essential step in the viral life cycle, virus entry into target cells. Influenza virus HA is synthesised as a precursor protein in infected cells and requires cleavage by host cell proteases to transit into an active form. Cleavage is essential for influenza virus infectivity and the HA‐processing proteases are attractive targets for therapeutic intervention. It is well established that cleavage by ubiquitously expressed subtilisin‐like proteases is a hallmark of highly pathogenic avian influenza viruses (HPAIV). In contrast, the nature of the proteases responsible for cleavage of HA of human influenza viruses and low pathogenic avian influenza viruses (LPAIV) is not well understood. Recent studies suggest that cleavage of HA of human influenza viruses might be a cell‐associated event and might be facilitated by the type II transmembrane serine proteases (TTSPs) TMPRSS2, TMPRSS4 and human airway trypsin‐like protease (HAT). Here, we will introduce the different concepts established for proteolytic activation of influenza virus HA, with a particular focus on the role of TTSPs, and we will discuss their implications for viral tropism, pathogenicity and antiviral intervention. Copyright © 2010 John Wiley & Sons, Ltd.
Cumulative effects of restoration efforts on ecological characteristics of an open water area within the Upper Mississippi River
Authors: Gray B. R. , Shi W. , Houser J. N. , Rogala J. T. , Guan Z. , Cochran‐Biederman J. L. 
Published: May 2010

AbstractEcological restoration efforts in large rivers generally aim to ameliorate ecological effects associated with large‐scale modification of those rivers. This study examined whether the effects of restoration efforts—specifically those of island construction—within a largely open water restoration area of the Upper Mississippi River (UMR) might be seen at the spatial scale of that 3476 ha area. The cumulative effects of island construction, when observed over multiple years, were postulated to have made the restoration area increasingly similar to a positive reference area (a proximate area comprising contiguous backwater areas) and increasingly different from two negative reference areas. The negative reference areas represented the Mississippi River main channel in an area proximate to the restoration area and an open water area in a related Mississippi River reach that has seen relatively little restoration effort. Inferences on the effects of restoration were made by comparing constrained and unconstrained models of summer chlorophyll a (CHL), summer inorganic suspended solids (ISS) and counts of benthic mayfly larvae. Constrained models forced trends in means or in both means and sampling variances to become, over time, increasingly similar to those in the positive reference area and increasingly dissimilar to those in the negative reference areas. Trends were estimated over 12‐ (mayflies) or 14‐year sampling periods, and were evaluated using model information criteria. Based on these methods, restoration effects were observed for CHL and mayflies while evidence in favour of restoration effects on ISS was equivocal. These findings suggest that the cumulative effects of island building at relatively large spatial scales within large rivers may be estimated using data from large‐scale surveillance monitoring programs. Published in 2010 by John Wiley & Sons, Ltd.
Thermal regime suitability: Assessment of upstream range restoration potential for Colorado pikeminnow, a warmwater endangered fish
Authors: Osmundson D. B. 
Published: May 2010

AbstractDams have reduced distribution of the endangered Colorado pikeminnow Ptychocheilus lucius in the upper Colorado River basin: low‐head diversion dams blocked upstream passage and large dams inundated free‐flowing segments and cooled downstream reaches with deep‐water releases. To date, range restoration efforts in the Colorado and Gunnison Rivers have focused on building fish ladders around diversion dams to allow recolonization of upstream reaches. Upstream thermal suitability for this warmwater cyprinid was assessed using temperature data and existing distributional information from river reaches where Colorado pikeminnow movements were unrestricted. Among‐site thermal regime comparisons were made using mean annual thermal units (ATU), derived from mean daily temperatures during 1986–2005 and the relation between temperature and Colorado pikeminnow growth. Upstream distributional limits in the Yampa and Gunnison Rivers occurred where in‐channel thermal regimes fell below a long‐term mean of 47–50 ATU, suggesting that two Colorado River fish ladders will make available an estimated 17 km of thermally suitable habitat. A Gunnison River fish ladder successfully re‐established access to 54 km of suitable habitat, but 32 km of critical habitat upstream remains unsuitable. Suitability there could be achieved by raising temperatures only 1–2°C from late May to mid‐October with installation of a temperature control device on an upstream dam. Maximum, main‐channel, summer temperatures did not limit Colorado pikeminnow distribution in downstream reaches of the upper Colorado River. Published in 2010 by John Wiley & Sons, Ltd.
Development of a benthic macroinvertebrate flow sensitivity index for Canadian rivers
Authors: Armanini D. G. , Horrigan N. , Monk W. A. , Peters D. L. , Baird D. J. 
Published: May 2010

AbstractWidespread alteration of flow regimes requires guidelines for the protection of river ecosystems based on sound science. Preservation of the biodiversity within river ecosystems and sustaining natural ecological functions are key aspects of their management. However, the relationship between the biota and flow‐related phenomena is poorly understood and, as a consequence, over‐simplistic hydrology‐based guidelines for river management have been adopted without establishing clear indicators of success. In the present paper, we aim to support the improvement of guidelines for flow (current velocity) management by developing a flow sensitivity index based on macroinvertebrates for Canadian rivers. Using benthic macroinvertebrate (BMI) samples collected by the Canadian Aquatic Biomonitoring Network (CABIN), current velocity preferences for the 55 most common invertebrate taxa across a range of reference and potential reference sites were derived. A Canadian Ecological Flow Index (CEFI) was developed based on these preferences. By testing the index against independent data, CEFI was found to respond mainly to changes in hydraulic conditions, and was minimally influenced by confounding factors (e.g. stream type, organic enrichment). The index was further validated using two independent data sets from the west and east of Canada, suggesting countrywide applicability of the method. In conclusion, we have developed a practical approach to evaluate relationships between hydrological regime and an important component of the river biota, permitting the development of an index which has good potential as an indicator for the effects of flow alteration. Moreover, we outline how the CEFI could be used as a tool for the development of holistic guidelines for the estimation of riverine flow needs. Copyright © 2010 Crown in the right of Canada and John Wiley & Sons, Ltd.
Satellite radio interfaces compatible to 3GPP WCDMA system
Authors: Kim Hee Wook , Lee Ho‐Jin , Martin Béatrice , Chuberre N. , Corazza G. E. , Vanelli‐Coralli A. 
Published: May 2010

AbstractThis paper provides an overview of a technical study on the satellite radio interfaces based on 3GPP WCDMA system. First, the outcome of the technical study is introduced, which has been carried out by the Mobile Satellite System Working Group of the ETSI Satellite Earth Satellite Technical Committee (ETSI TC SES MSS). The study dealt with the configurations and performance of the 3GPP WCDMA (UTRAN) radio interface over a satellite link. Second, as an evolution of satellite‐specific radio interface, the study results are addressed on the possible adaptations of WCDMA to the satellite link in order to maximize the radio link performance. The resultant outcome of the study was reflected in a detail on the G and C families of the satellite radio interface of the ITU‐R Recommendation M.1457, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
A cooperative transmit diversity scheme for mobile satellite broadcasting systems
Authors: Ahn Do Seob , Kim Sooyoung , Kim Hee Wook , Park Dong‐Chul 
Published: May 2010

AbstractIn this study, we propose an efficient cooperative diversity scheme for mobile satellite multimedia broadcasting systems. The proposed scheme is a transmit diversity technique for adapting different channel environments, and thus, no channel quality information from the return link is needed. In the proposed scheme, we utilize space–time block codes and rate‐compatible turbo codes to achieve diversity gains and additional coding gains, respectively. The satellite and several repeaters on the ground cooperate to send the encoded signals, enabling the user terminal to realize diversity gain. The simulation results demonstrate that the proposed scheme can provide greatly improved performance. The simulation results in this study show that we can achieve about a 0.8 and 2.3 dB power gain by using the proposed cooperative diversity scheme without and with maximal ratio combining schemes, respectively, compared with the conventional scheme even, with a higher code rate. Copyright © 2010 John Wiley & Sons, Ltd.
Wetting of Cu substrates with micrometer and nanometer grains by molten Sn‐3.5Ag‐0.7Cu alloy
Authors: Shen Ping , Yin Zhongfa , Yang Jun , Sun Jianxin , Jiang Zhonghao , Jiang Qichuan 
Published: May 2010

AbstractWetting behaviors and interfacial microstructures of molten Sn‐3.5Ag‐0.7Cu drops on micrometer‐ and nanometer‐grained Cu substrates were studied. The wettability of the micrometer‐grained Cu substrates was found to be better than that of the nanometer‐grained substrates. Moreover, Kirkendall voids were observed at the interface of the nanometer‐grained Cu substrates but not of the micrometer‐grained substrates. It is presumed that the nanocrystalline surfaces are more prone to adsorption of impurities, thus reducing the surface free energy. On the other hand, its atomic diffusivity is greatly enhanced. As a result, the wettability deteriorates while the Kirkendall voids readily proliferate. Copyright © 2010 John Wiley & Sons, Ltd.
Surface characterization on graphitization of nanodiamond powder annealed in nitrogen ambient
Authors: Xie F. Y. , Xie W. G. , Gong L. , Zhang W. H. , Chen S. H. , Zhang Q. Z. , Chen J. 
Published: May 2010

AbstractA nanodiamond thin film is deposited on a single crystal silicon substrate by dip‐coating technique. Surface characterization of the unannealed nanodiamond sample, and the samples annealed at various temperatures in nitrogen ambient, is conducted by XPS and Raman spectroscopy. The fitting data of the C1s core level XPS peak reveal that the sp2/sp3 ratio in the unannealed sample and the sample annealed at 900 °C and 1500 °C are 0.44, 0.55 and 6.08 respectively. All spectra including the C1s core level XPS spectrum, the plasmon energy‐loss spectrum associated with C1s peak, C KVV Auger spectrum of the sample annealed at 900 °C are similar to those of the unannealed sample. However, the spectra of the sample annealed at 1500 °C are very different. Annealing at 900 °C fails to produce appreciable graphitization, and an onion‐like carbon structure with a small diamond core is formed when the nanodiamond is heated to 1500 °C. Copyright © 2010 John Wiley & Sons, Ltd.