bluuebunny/crossref_metadata_2025_split huggingface dataset:
How are new citation‐based journal indicators adding to the bibliometric toolbox?
Authors: Leydesdorff Loet 
Published: February 2009

AbstractThe launching of Scopus and Google Scholar, and methodological developments in social‐network analysis have made many more indicators for evaluating journals available than the traditional impact factor, cited half‐life, and immediacy index of the ISI. In this study, these new indicators are compared with one another and with the older ones. Do the various indicators measure new dimensions of the citation networks, or are they highly correlated among themselves? Are they robust and relatively stable over time? Two main dimensions are distinguished—size and impact—which together shape influence. The h‐index combines the two dimensions and can also be considered as an indicator of reach (like Indegree). PageRank is mainly an indicator of size, but has important interactions with centrality measures. The Scimago Journal Ranking (SJR) indicator provides an alternative to the journal impact factor, but the computation is less easy.
Data fusion according to the principle of polyrepresentation
Authors: Larsen Birger , Ingwersen Peter , Lund Berit 
Published: February 2009

AbstractWe report data fusion experiments carried out on the four best‐performing retrieval models from TREC 5. Three were conceptually/algorithmically very different from one another; one was algorithmically similar to one of the former. The objective of the test was to observe the performance of the 11 logical data fusion combinations compared to the performance of the four individual models and their intermediate fusions when following the principle of polyrepresentation. This principle is based on cognitive IR perspective (Ingwersen & Järvelin, 2005) and implies that each retrieval model is regarded as a representation of a unique interpretation of information retrieval (IR). It predicts that only fusions of very different, but equally good, IR models may outperform each constituent as well as their intermediate fusions. Two kinds of experiments were carried out. One tested restricted fusions, which entails that only the inner disjoint overlap documents between fused models are ranked. The second set of experiments was based on traditional data fusion methods. The experiments involved the 30 TREC 5 topics that contain more than 44 relevant documents. In all tests, the Borda and CombSUM scoring methods were used. Performance was measured by precision and recall, with document cutoff values (DCVs) at 100 and 15 documents, respectively. Results show that restricted fusions made of two, three, or four cognitively/algorithmically very different retrieval models perform significantly better than do the individual models at DCV100. At DCV15, however, the results of polyrepresentative fusion were less predictable. The traditional fusion method based on polyrepresentation principles demonstrates a clear picture of performance at both DCV levels and verifies the polyrepresentation predictions for data fusion in IR. Data fusion improves retrieval performance over their constituent IR models only if the models all are quite conceptually/algorithmically dissimilar and equally and well performing, in that order of importance.
Identifying Web search session patterns using cluster analysis: A comparison of three search environments
Authors: Wolfram Dietmar , Wang Peiling , Zhang Jin 
Published: February 2009

AbstractSession characteristics taken from large transaction logs of three Web search environments (academic Web site, public search engine, consumer health information portal) were modeled using cluster analysis to determine if coherent session groups emerged for each environment and whether the types of session groups are similar across the three environments. The analysis revealed three distinct clusters of session behaviors common to each environment: “hit and run” sessions on focused topics, relatively brief sessions on popular topics, and sustained sessions using obscure terms with greater query modification. The findings also revealed shifts in session characteristics over time for one of the datasets, away from “hit and run” sessions toward more popular search topics. A better understanding of session characteristics can help system designers to develop more responsive systems to support search features that cater to identifiable groups of searchers based on their search behaviors. For example, the system may identify struggling searchers based on session behaviors that match those identified in the current study to provide context sensitive help.
Synthesis and Structural Characterization of Neutral Hexacoordinate Silicon(IV) Complexes with SiO2N4 Skeletons
Authors: Metz Stefan , Burschka Christian , Tacke Reinhold 
Published: February 2009

AbstractSurrounded by six: A series of novel neutral hexacoordinate silicon(IV) complexes with SiO2N4 skeletons, containing two bidentate monoanionic O,N ligands and two monoanionic NCX (X = O, S) ligands, was synthesized. The formation of the title compounds involved some unexpected transformations of the bidentate O,N ligands.magnified imageA series of novel neutral hexacoordinate silicon(IV) complexes with SiO2N4 skeletons (compounds 4–8) was synthesized and structurally characterized by single‐crystal X‐ray diffraction and solid‐state NMR spectroscopy (13C, 15N, 29Si). The silicon(IV) complexes each contain two bidentate monoanionic O,N Schiff base ligands and two cyanato‐N or thiocyanato‐N ligands. Compounds 4–8 were prepared from Si(NCO)4 or Si(NCS)4, whereby the complex formation involved some unexpected chemical transformations of the ligands.
Frischbetondruck bei Verwendung von Selbstverdichtendem Beton
Authors: Graubner Carl‐Alexander , Proske Tilo 
Published: February 2009

AbstractAuf der Grundlage von Untersuchungen zum Reibungs‐ und Verformungsverhalten von Selbstverdichtendem Beton (SVB) in sehr jungem Betonalter wurden analytische Modelle zur Berechnung des Frischbetondrucks auf lotrechte Schalungen entwickelt. Neben einem Modell, welches auf der Silotheorie basiert und zeitlich veränderliche Materialparameter des Frischbetons berücksichtigt, ermöglicht ein vereinfachtes Erstarrungsmodell die rechnerische Abschätzung des Frischbetondrucks. Auf den theoretischen Untersuchungen aufbauend wurde – basierend auf dem Teilsicherheitskonzept – ein praxisrelevanter Berechnungsvorschlag erarbeitet. Es zeigt sich, dass auch bei SVB für die Bemessung von Schalung und Rüstung oftmals eine geringere Belastung als der hydrostatische Betondruck angesetzt werden kann. Die wichtigste Steuerungsmöglichkeit auf der Baustelle stellt dabei die Betoniergeschwindigkeit dar.
Analysis of functional divergence within two structurally related glycoside hydrolase families
Authors: Mertz Blake , Gu Xun , Reilly Peter J. 
Published: February 2009

AbstractTwo glycoside hydrolase (GH) families were analyzed to detect the presence of functional divergence using the program DIVERGE. These two families, GH7 and GH16, each contain members related by amino acid sequence similarity, retaining hydrolytic mechanisms, and catalytic residue identity. GH7 and GH16 comprise GH Clan B, with a shared β‐jelly roll topology and mechanism. GH7 contains fungal cellobiohydrolases and endoglucanases and is divided into five main subfamilies, four of the former and one of the latter. Cluster comparisons between three of the cellobiohydrolase subfamilies and the endoglucanase subfamily identified specific amino acid residues that play a role in the functional divergence between the two enzyme types. GH16 contains subfamilies of bacterial agarases, xyloglucosyl transferases, 1,3‐β‐D‐glucanases, lichenases, and other enzymes with various substrate specificities and product profiles. Four cluster comparisons between these four main subfamilies again have identified amino acid residues involved in functional divergence between the subfamilies. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 478–495, 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
On the use of ESI‐QqTOF‐MS/MS for the comparative sequencing of nucleic acids
Authors: Oberacher Herbert , Pitterl Florian 
Published: February 2009

AbstractThe usability of a quadrupole—quadrupole—time‐of‐flight (QqTOF) instrument for the tandem mass spectrometric sequencing of oligodeoxynuleotides was investigated. The sample set consisted of 21 synthetic oligodeoxynucleotides ranging in length from 5 to 42 nucleotides. The sequences were randomly selected. For the majority of tested oligonucleotides, two or three different charge states were selected as precursor ions. Each precursor ion was fragmented applying several different collision voltages. Overall 282 fragment ion mass spectra were acquired. Computer‐aided interpretation of fragment ion mass spectra was accomplished with a recently introduced comparative sequencing algorithm (COMPAS). The applied version of COMPAS was specifically optimized for the interpretation of information‐rich spectra obtained on the QqTOF. Sequences of oligodeoxynucleotides as large as 26‐mers were correctly verified in >94% of cases (182 of 192 spectra acquired). Fragment ion mass spectra of larger oligonucleotides were not specific enough for sequencing. Because of the occurrence of extensive internal fragmentation causing low sequence coverage paired with a high probability of assigning fragment ions to wrong sequences, tandem mass spectra obtained from oligonucleotides consisting of 30 and more nucleotides could not be used for sequence verification neither manually nor with COMPAS. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 401–409, 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
Rational shape engineering of the filamentous protein γ prefoldin through incremental gene truncation
Authors: Whitehead Timothy A. , Je Elizabeth , Clark Douglas S. 
Published: February 2009

AbstractAn enticing possibility in nanotechnology is to use proteins as templates for the positioning of molecules in regular patterns with nanometer precision over large surface areas. However, the ability to redesign protein quaternary structure to construct new shapes remains underdeveloped. In the present work, we have engineered the dimensions of a filamentous protein, the γ prefoldin (γ PFD) from the hyperthermophile Methanocaldococcus jannaschii, and have achieved controllable attachment of filaments in a specific orientation on a carbon surface. Four different constructs of γ PFD were generated in which the coiled coils extending from the association domain are progressively truncated. Three of the truncation constructs form well‐defined filaments with predictable dimensions according to transmission electron microscopy. Two of these constructs had 2D persistence lengths similar to that of γ PFD at 300–740 nm. In contrast, the 2D persistence length of the shortest truncation mutant was 3500 nm, indicating that the filament adsorbs along a different axis than the other constructs with its two rows of coiled coils facing out from the surface. The elastic moduli of the filaments range from 0.7–2.1 GPa, similar to rigid plastics and within the lower limit for proteins whose primary intermolecular interaction is hydrogen bonding. These results demonstrate a versatile approach for controlling the overall dimensions and surface orientation of protein filaments, and expand the toolbox by which to tune two overall dimensions in protein space for the creation of templated materials over a wide variety of conditions. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 496–503, 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
Differential Regulation of Protein Subdomain Activity with Caged Bivalent Ligands
Authors: Mayer Günter , Müller Jens , Mack Timo , Freitag Daniel F. , Höver Thomas , Pötzsch Bernd , Heckel Alexander 
Published: February 2009

AbstractSubtle change: Spatiotemporal modulation of individual protein subdomains with light as the trigger signal becomes possible by using bivalent aptamers and introducing photolabile “caging groups” to switch individual aptamer modules ON or OFF differentially. To the best of our knowledge, this is the first study to show that it is possible to modulate individual domain activity in aptamers, and thus also domain activity in proteins, with light.magnified image
Novel mobile telemedicine system for real‐time transmission of out‐of‐hospital ECG data for ST‐elevation myocardial infarction
Authors: Otsuka Yoritaka , Yokoyama Hiroyuki , Nonogi Hiroshi 
Published: February 2009

AbstractThe guidelines recommend routine use of 12‐lead electrocardiogram (ECG) and advance notification to the emergency department for patients with ST‐elevation myocardial infarction (STEMI). However, transmission of out‐of‐hospital 12‐lead ECG to emergency department is still not widely practiced and ECG interpretation before arrival at the emergency department is not established. We have developed a novel mobile telemedicine system to transmit real‐time 12‐lead ECG data between moving ambulances and in‐hospital physicians in cardiovascular emergency cases. When used, this system immediately identifies patients with STEMI and it is coupled to a centralized system to alert the cardiac catheterization teams to prepare for prompt intervention. This report presents the first case with STEMI who was successfully treated using this novel mobile telemedicine system. © 2009 Wiley‐Liss, Inc.
Very long‐term results comparing a simple versus a complex stenting strategy in the treatment of coronary bifurcation lesions
Authors: Sheiban Imad , Andrea Infantino Vincenzo , Colombo Francesco , Bollati Mario , Omedè Pierluigi , Moretti Claudio , Sciuto Filippo , Siliquini Roberta , Chiadò Simone , Paolo Trevi Gian , Biondi‐Zoccai Giuseppe 
Published: February 2009

AbstractBackground:The optimal stenting strategy for coronary bifurcation lesions has not yet been defined, especially given the lack of very long‐term data (>24 months). We compared our long‐term results of a simple vs complex stenting strategy in patients with bifurcation lesions.Methods:We retrospectively selected subjects undergoing percutaneous coronary intervention (PCI) with stenting in a bifurcation lesion between June 2002 and December 2005, comparing those treated with a simple technique vs those treated with a complex one. The primary end‐point was the rate of major adverse cardiac events (MACE) at >24 months of follow‐up.Results:A total of 326 patients were included, 64.7% treated with a simple technique (Group A) and 35.3% with a complex strategy (Group B). Drug‐eluting stents were used in 82.0% and 73.0%, respectively (P = 0.059), final kissing balloon in 47.9% and 53.0% (P = 0.37), and procedural success obtained in 99.5% and 99.1% (P = 0.66). After a median of 34 months, MACE occurred in 52 (26.5%) in Group A and in 32 (31.4%) in Group B (P = 0.37), cardiac death in six (3.1%) vs four (3.9%, P = 0.70), myocardial infarction in 13 (6.6%) vs 6 (5.9%, P = 0.80), target vessel revascularization in 36 (18.4%) vs 29 (28.4%, P = 0.04), and bypass in five (2.6%) vs two (2%, P = 0.74). Definite stent thrombosis was adjudicated in two (1%) vs one (0.9%, P = 0.98).Conclusions:This study, comparing simple and complex stenting strategies for the treatment of coronary bifurcation lesions, shows that both techniques are associated with favorable clinical results and low adverse events rates at long‐term follow‐up. © 2009 Wiley‐Liss, Inc.
Modelling of partition constants: linear solvation energy relationships or PLS regression?
Authors: Liu Tao , Öberg Tomas 
Published: February 2009

AbstractEstimation methods for partition constants are needed in many fields of engineering and science. The partitioning between phases is determined by the free energy of the transfer and all estimation methods must therefore describe the same entity. Linear solvation energy relationships (LSERs) try to split the contributions to van der Waals and polar interactions into directly interpretable solute descriptors, while projection‐based regression methods can accomplish a similar dimensionality reduction from a set of theoretical descriptors. Here, we use the partitioning between octanol and water (Kow) and water solubility (Sw) to investigate similarities and differences between LSER and partial least squares regression (PLSR) models. The similarities in model structure are described, and shown to transform into a comparable prediction performance. We also demonstrate the opportunity to accomplish an analogous chemical interpretation of a PLSR model—either directly or through a linear transformation of the PLS factors—as with an LSER model. Much of the alleged difference between the mechanistic or semi‐empirical LSER and the statistical PLSR models will then disappear. The choice of a modelling approach should therefore primarily be driven by the availability of data and predictive performance. Copyright © 2009 John Wiley & Sons, Ltd.
On the “Gluing” Effect of Lithium: The Lithium‐Driven Assembly of Circum‐Arranged, Edge‐Fused Cyclopentadienyl Lithium Compounds and Aza Analogues
Authors: Saá José M. , Yañez Manuel 
Published: February 2009

AbstractPredictions(DFT/B3LYP calculations) are that cyclopentadienyl lithium edge‐fused to [n]circulenes in a circum‐like manner should self‐assemble as rod‐like, nanometer long, supersandwich compounds (see figure). On the contrary, triazolyl lithium analogues prefer to dimerize thereby giving rise to shell‐like dimers of variable curvatures.magnified imageThis study is aimed at exploring M. Etter's (T. W. Panunto, Z. Urbanczyk‐Lipkowska, R. Jonhson, M. Etter,J. Am. Chem. Soc.1987,109, 7786–7797) bottom‐up approach towards the design of organic‐solid sate materials. Guided by the electrostatic paste (“gluing”) effect of lithium, we examined the self‐assembly modes of a series of cyclopentadienyl lithium edge‐fused to benzene, as well as to [n]circulenes, arranged in a circum‐like manner by means of DFT/B3 LYP calculations. We have also examined the self‐assembly modes of the analogous triazolyl derivatives. Generally, well defined trends have been found. Thus, whereas cylcopentadienyl derivatives1,3and5tend to aggregate as rod‐like, nanometer‐long, supersandwich compounds, the corresponding triazolyl analogues2,4and6tend to dimerize thus giving rise to shell‐like dimers of variable curvatures. In our view, M. Etter's bottom‐up approach combined with high level calculations appears to have great potential for designing complex molecular architectures and nanostructures. Hopefully, these studies will spur the activity of synthetic and materials chemists.
Intramolecular Axial Ligation of Zinc Porphyrin Cores with Triazole Links within Dendrimers
Authors: Kimura Mutsumi , Nakano Yasuhiro , Adachi Naoya , Tatewaki Yoko , Shirai Hirofusa , Kobayashi Nagao 
Published: February 2009

AbstractStable ligation: A series of dendritic porphyrins, such as that depicted in which benzyl ether dendrons were linked to a porphyrin core through 1,2,3‐triazole links, was synthesized. Absorption and fluorescence spectra showed a stable axial ligation at the zinc center of the porphyrin core by triazole links in dendritic wedges and indicated that the position of the triazole links strongly affected the stability of the axial ligation within the dendrimer.magnified imageA series of dendritic porphyrins 7–9 and 12, in which benzyl ether dendrons were linked to a porphyrin core through 1,2,3‐triazole links, were synthesized by CuI‐catalyzed cycloaddition of azides and alkynes. Absorption and fluorescence spectra showed a stable axial ligation at the zinc center of the porphyrin core by triazole links in dendritic wedges and indicated that the position of the triazole links strongly affected the stability of the axial ligation within the dendrimer. When the porphyrin core was surrounded by aryl ether dendrons having anionic termini and triazole linkers, a significant rate enhancement for photoinduced electron transfer was observed compared with a similar water‐soluble dendritic zinc porphyrin lacking triazole linkers. These triazole links constituted a direct pathway within the dendrimer architecture for electron transfer between the zinc porphyrin core and peripheral electron acceptors.
Enhancing Gelation Ability of a Dendritic Gelator through Complexation with a Polyelectrolyte
Authors: Zhang Zijian , Yang Miao , Zhang Xinjun , Zhang Lichu , Liu Bo , Zheng Ping , Wang Wei 
Published: February 2009

AbstractLet's stick together: The gelation ability of a dendritic gelator has been enhanced by its complexation with a polyelectrolyte (see figure). This concept provides a route to construct novel functional or ordered materials by complexation of other low‐molecular‐mass functional species with polyelectrolytes.magnified imageA poly(urethane amide) (PUA) dendron with long alkyl chains on its periphery was synthesized and then attached to the backbone of a polyelectrolyte, in which each unit contained a positive charge, by ionizing the carboxyl groups on the apexes of the dendrons to form a dendronized polymer. We found that both the PUA dendron and the dendronized polymer could form organogels in toluene. Interestingly, both the minimum gelation concentration and the gelation time of the dendronized polymer gelator were greatly reduced compared with the dendron alone. Our investigations showed that in the gel phase the intermolecular hydrogen bonding between adjacent dendrons creates similar supramolecular structures in both the dendron and the dendronized polymer gelator, which immobilize solvent molecules by means of interactions between dendrons and solvent molecules. Further studies on the gelation kinetics indicated that the polyelectrolyte backbone plays an important role in prearranging the attached dendritic gelators orderly and quickly into the supramolecular structures through a nucleation–elongation mechanism. Therefore, the gel‐forming ability of the dendritic PUA gelator is enhanced by being complexed with the polyelectrolyte. In this work, this positive macromolecular effect is discussed in detail.
The Azulene Framework as a Novel Arene Bioisostere: Design of Potent Dopamine D4 Receptor Ligands Inducing Penile Erection
Authors: Löber Stefan , Tschammer Nuska , Hübner Harald , Melis Maria Rosaria , Argiolas Antonio , Gmeiner Peter 
Published: February 2009

AbstractBlue makes it happen: The non‐uniform charge distribution of the blue colored azulene framework is highly suitable for the bioisosteric replacement of bicyclic heteroarene moieties. Showing an analogous binding mode as heterocyclic dopamine D4 receptor‐selective lead compounds, the induction of penile erection in rats over a greater range of doses indicates a putative advantage of the rationally developed azulene derivative 2 b over apomorphine.magnified image