bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal, morphological, and X‐ray study of polymer‐clay nanocomposites
Authors: Nigam Vineeta , Soni Hitesh , Saroop Madhumita , Verma G.L. , Bhattacharya A.S. , Setua D.K. 
Published: November 2011

AbstractSynthesis and characterization of polymer nanocomposites consisting of diglycidyl ether of bisphenol‐A with inorganic as well as organically modified nanosized clay fillers, for example, vermiculites and montmorillonite, obtained from trade, are studied. Confirmations of intercalation and exfoliation characteristics of these fillers into the cured epoxy resin matrix have been investigated by wide angle X‐ray diffraction studies. Scanning electron microscopy and atomic force microscopy techniques have been adopted to assess the nature of filler dispersion, size of the agglomerates, and the polymer‐filler adhesion. While significant improvement in the mechanical properties (i.e., tensile, flexural strength, and modulus) has been observed, the thermo‐oxidative stability of the composites measured by thermogravimetric analysis showed only marginal improvement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Commenting on YouTube videos: From guatemalan rock to El Big Bang
Authors: Thelwall Mike , Sud Pardeep , Vis Farida 
Published: November 2011

AbstractYouTube is one of the world's most popular websites and hosts numerous amateur and professional videos. Comments on these videos might be researched to give insights into audience reactions to important issues or particular videos. Yet, little is known about YouTube discussions in general: how frequent they are, who typically participates, and the role of sentiment. This article fills this gap through an analysis of large samples of text comments on YouTube videos. The results identify patterns and give some benchmarks against which future YouTube research into individual videos can be compared. For instance, the typical YouTube comment was mildly positive, was posted by a 29‐year‐old male, and contained 58 characters. About 23% of comments in the complete comment sets were replies to previous comments. There was no typical density of discussion on YouTube videos in the sense of the proportion of replies to other comments: videos with both few and many replies were common. The YouTube audience engaged with each other disproportionately when making negative comments, however; positive comments elicited few replies. The biggest trigger of discussion seemed to be religion, whereas the videos attracting the least discussion were predominantly from the Music, Comedy, and How to & Style categories. This suggests different audience uses for YouTube, from passive entertainment to active debating.
Predictive effects of structural variation on citation counts
Authors: Chen Chaomei 
Published: November 2011

AbstractA critical part of a scientific activity is to discern how a new idea is related to what we know and what may become possible. As the number of new scientific publications arrives at a rate that rapidly outpaces our capacity of reading, analyzing, and synthesizing scientific knowledge, we need to augment ourselves with information that can effectively guide us through the rapidly growing intellectual space. In this article, we address a fundamental issue concerning what kinds of information may serve as early signs of potentially valuable ideas. In particular, we are interested in information that is routinely available and derivable upon the publication of a scientific paper without assuming the availability of additional information such as its usage and citations. We propose a theoretical and computational model that predicts the potential of a scientific publication in terms of the degree to which it alters the intellectual structure of the state of the art. The structural variation approach focuses on the novel boundary‐spanning connections introduced by a new article to the intellectual space. We validate the role of boundary‐spanning in predicting future citations using three metrics of structural variation—namely, modularity change rate, cluster linkage, and Centrality Divergence—along with more commonly studied predictors of citations such as the number of coauthors, the number of cited references, and the number of pages. Main effects of these factors are estimated for five cases using zero‐inflated negative binomial regression models of citation counts. Key findings indicate that (a) structural variations measured by cluster linkage are a better predictor of citation counts than are the more commonly studied variables such as the number of references cited, (b) the number of coauthors and the number of references are both good predictors of global citation counts to a lesser extent, and (c) the Centrality Divergence metric is potentially valuable for detecting boundary‐spanning activities at interdisciplinary levels. The structural variation approach offers a new way to monitor and discern the potential of newly published papers in context. The boundary‐spanning mechanism offers a conceptually simplified and unifying explanation of the roles played by commonly studied extrinsic properties of a publication in the study of citation behavior.
Interaction of hesperetin glucuronide conjugates with human BCRP, MRP2 and MRP3 as detected in membrane vesicles of overexpressing baculovirus‐infected Sf9 cells
Authors: Brand Walter , Oosterhuis Berend , Krajcsi Peter , Barron Denis , Dionisi Fabiola , van Bladeren Peter J. , Rietjens Ivonne M. C. M. , Williamson Gary 
Published: November 2011

ABSTRACTThe citrus flavonoid hesperetin (4′‐methoxy‐3′,5,7‐trihydroxyflavanone) is the aglycone of hesperidin, the major flavonoid present in sweet oranges. Hesperetin 7‐O‐glucuronide (H7G) and hesperetin 3′‐O‐glucuronide (H3′G) are the two most abundant metabolites of hesperetin in vivo. In this study, their interaction with specific ABC transporters, believed to play a role in the disposition and bioavailability of hesperetin, was studied using Sf9 membranes from cells overexpressing human BCRP (ABCG2), MRP2 (ABCC2) and MRP3 (ABCC3). Both H7G and H3′G were tested for their potential to activate and inhibit ATPase activity, and to inhibit vesicular transport by these transporters. Both H7G and H3′G demonstrated interaction with all tested ABC transporters, especially with BCRP and MRP3. An interesting difference between H7G and H3′G was seen with respect to the interaction with BCRP: H7G stimulated the ATPase activity of BCRP up to 76% of the maximal effect generated by the reference activator sulfasalazine, with an EC50 of 0.45 µ m, suggesting that H7G is a high affinity substrate of BCRP, whereas H3′G did not stimulate BCRP ATPase activity. Only moderate inhibition of BCRP ATPase activity at high H3′G concentrations was observed. This study provides information on the potential of hesperetin glucuronide conjugates to act as specific ABC transporter substrates or inhibitors and indicates that regio‐specific glucuronidation could affect the disposition of hesperetin. Copyright © 2011 John Wiley & Sons, Ltd.
Starting a new life: Sperm PLC‐zeta mobilizes the Ca2+ signal that induces egg activation and embryo development
Authors: Nomikos Michail , Swann Karl , Lai F. Anthony 
Published: November 2011

AbstractWe have discovered that a single sperm protein, phospholipase C‐zeta (PLCζ), can stimulate intracellular Ca2+ signalling in the unfertilized oocyte (‘egg’) culminating in the initiation of embryonic development. Upon fertilization by a spermatozoon, the earliest observed signalling event in the dormant egg is a large, transient increase in free Ca2+ concentration. The fertilized egg responds to the intracellular Ca2+ rise by completing meiosis. In mammalian eggs, the Ca2+ signal is delivered as a train of long‐lasting cytoplasmic Ca2+ oscillations that begin soon after gamete fusion and persist beyond the completion of meiosis. Sperm PLCζ effects Ca2+ release from egg intracellular stores by hydrolyzing the membrane lipid PIP2 and consequent stimulation of the inositol 1,4,5‐trisphosphate (InsP3) receptor Ca2+‐signalling pathway, leading to egg activation and early embryogenesis. Recent advances have refined our understanding of how PLCζ induces Ca2+ oscillations in the egg and also suggest its potential dysfunction as a cause of male infertility.
Updating risk prediction tools: A case study in prostate cancer
Authors: Ankerst Donna P. , Koniarski Tim , Liang Yuanyuan , Leach Robin J. , Feng Ziding , Sanda Martin G. , Partin Alan W. , Chan Daniel W. , Kagan Jacob , Sokoll Lori , Wei John T. , Thompson Ian M. 
Published: November 2011

AbstractOnline risk prediction tools for common cancers are now easily accessible and widely used by patients and doctors for informed decision‐making concerning screening and diagnosis. A practical problem is as cancer research moves forward and new biomarkers and risk factors are discovered, there is a need to update the risk algorithms to include them. Typically, the new markers and risk factors cannot be retrospectively measured on the same study participants used to develop the original prediction tool, necessitating the merging of a separate study of different participants, which may be much smaller in sample size and of a different design. Validation of the updated tool on a third independent data set is warranted before the updated tool can go online. This article reports on the application of Bayes rule for updating risk prediction tools to include a set of biomarkers measured in an external study to the original study used to develop the risk prediction tool. The procedure is illustrated in the context of updating the online Prostate Cancer Prevention Trial Risk Calculator to incorporate the new markers %freePSA and [‐2]proPSA measured on an external case–control study performed in Texas, U.S.. Recent state‐of‐the art methods in validation of risk prediction tools and evaluation of the improvement of updated to original tools are implemented using an external validation set provided by the U.S. Early Detection Research Network.
Development of thermostable Candida antarctica lipase B through novel in silico design of disulfide bridge
Authors: Le Quang Anh Tuan , Joo Jeong Chan , Yoo Young Je , Kim Yong Hwan 
Published: November 2011

AbstractLipase B from Candida antarctica (CalB) is a versatile biocatalyst for various bioconversions. In this study, the thermostability of CalB was improved through the introduction of a new disulfide bridge. Analysis of the B‐factors of residue pairs in CalB wild type (CalB‐WT) followed by simple flexibility analysis of residues in CalB‐WT and its designated mutants using FIRST server were newly proposed to enhance the selective power of two computational tools (MODIP and DbD v1.20) to predict the possible disulfide bonds in proteins for the enhancement of thermostability. Five residue pairs (A162‐K308, N169‐F304, Q156‐L163, S50‐A273, and S239C‐D252C) were chosen and the respective amino acid residues were mutated to cysteine. In the results, CalB A162C‐K308C showed greatly improved thermostability while maintaining its catalytic efficiency compared to that of CalB‐WT. Remarkably, the temperature at which 50% of its activity remained after 60‐min incubation (T) of CalB A162C_K308C was increased by 8.5°C compared to that of CalB‐WT (55 and 46.5°C, respectively). Additionally, the half‐life at 50°C of CalB A162C‐K308C was 4.5‐fold higher than that of CalB‐WT (220 and 49 min, respectively). The improvement of thermostability of CalB A162C‐K308C was elucidated at the molecular level by molecular dynamics (MD) simulation. Biotechnol. Bioeng. 2012; 109:867–876. © 2011 Wiley Periodicals, Inc.
Neutral Nickel Oligo‐ and Polymerization Catalysts: The Importance of Alkyl Phosphine Intermediates in Chain Termination
Authors: Heyndrickx Wouter , Occhipinti Giovanni , Minenkov Yury , Jensen Vidar R. 
Published: November 2011

AbstractAn unconventional chain termination reaction has been explored for the SHOP (Shell higher olefin process)‐type, anilinotropone, and salicylaldiminato nickel‐based oligo‐ and polymerization catalysts by using density functional theory (DFT). Starting from the tetracoordinate alkyl phosphine complex, the termination reaction was found to involve a rearrangement of the alkyl chain to form a pentacoordinate β‐agostic complex, β‐hydride elimination, and olefinic chain dissociation and to compete with propagation at sufficiently high phosphine concentration and/or basicity. It provides the first complete and convincing mechanistic rationale for the decreasing chain lengths observed upon increasing phosphine concentration and basicity. The unconventional reaction was found to be a major termination pathway for the SHOP‐type catalyst and is very unlikely to lead to branching and olefin isomerization, which is critical for explaining why the SHOP catalyst, in contrast to the anilinotropone and salicylaldiminato catalysts, tends to lead to the oligomerization of ethylene to form linear α‐olefins. Based on our results we have proposed a new and extended catalytic cycle for the SHOP‐type ethylene oligomerization catalyst. Finally, the importance of the new termination reaction for the SHOP‐type catalyst suggests that this reaction may also operate with other ethylene oligomerization nickel catalysts. This prediction was confirmed for a pyrazolonatophosphine catalyst, for which the new termination route was found to be even more facile, which explains the short oligomers produced by this catalyst.
Remarkably Selective Recognition of Iodobenzene Derivatives by a Macrocyclic Bis‐PtII Metallohost
Authors: Trokowski Robert , Akine Shigehisa , Nabeshima Tatsuya 
Published: November 2011

AbstractWe designed and synthesized self‐assembled bis‐PtII dimer 1⋅4 BF4 with quino[8,7‐b][1,10]phenanthroline as an extended π‐face contact area, which acts as the first artificial receptor with high affinity toward iodinated aromatic compounds significantly based on noncovalent iodine⋅⋅⋅aromatic‐plane interactions in a “side‐on” fashion. Despite their structural similarity to a previously reported metallohost 24+ that bears 2,2′:6′,2′′‐terpyridine units, a dramatic change in selectivity toward substituted benzene derivatives was observed for 14+. 1H NMR spectroscopic titration revealed a high affinity of 14+ towards haloarenes, with exceptionally large association constants for 2‐iodophenol (Ka=16 000 M−1) and 1,2‐diiodobenzene (Ka=21 000 M−1), which are 93‐ and 140‐fold higher, respectively, than the values obtained for 24+. In addition, 14+ showed a remarkably high affinity and selectivity toward 2,6‐diiodophenol (Ka=35 000 M−1), which is an important substructure of the thyroid hormone T4. X‐ray crystallography and theoretical calculations strongly suggest that “side‐on” iodine⋅⋅⋅aromatic‐plane interactions and π–π stacking contribute to the strong 1,2‐diiodobenzene and 2,6‐diiodophenol binding. The results obtained here give unique and valuable insight into the nature of halogen atom interactions in their “side‐on” region with an electropositive aromatic plane, which may provide useful guidance for designing artificial receptors for iodinated biomolecules.
Clinical Impact of Off‐Label Cardiac Resynchronization Therapy in End‐Stage Heart Failure Patients on Continuous Intravenous Inotrope
Authors: Hara Masahiko , Mizuno Hiroya , Mizote Isamu , Nakatani Daisaku , Asano Yoshihiro , Sakata Yasushi , Nanto Shinsuke , Komuro Issei 
Published: November 2011

AbstractBackground:Potential benefits of off‐label cardiac resynchronization therapy (CRT) in end‐stage heart failure (EHF) patients have not been fully investigated.Hypothesis:Some EHF patients who are dependent on intravenous inotropes can benefit from CRT.Methods:We retrospectively enrolled 14 EHF patients who were dependent on intravenous inotropes at the time of CRT implantation. Mean duration of inotropic support was 51 ± 47 days before CRT device implantation. To identify the efficacy of CRT, we assessed the successful withdrawal rate from inotropic support and survival estimates after device implantation. We also tried to identify possible predictors for withdrawal by comparing patient demographics between successful withdrawal (SW) and nonwithdrawal (NW) groups.Results:Successful withdrawal was achieved in 9 (64%) of 14 patients 46 ± 33 days after CRT device implantation. Event‐free survival was longer in the SW group than in the NW group (810 ± 169 days vs 114 ± 34 days; P = 0.007). In addition, patients in the SW group showed a higher previous surgery rate (89% vs 20%; P = 0.010) and a lower grade of mitral regurgitation (median, 0 vs 2; P = 0.010) than those in the NW group.Conclusions:Our retrospective data showed potential benefits of CRT among EHFpatients. Treatment of mitral regurgitation might be an essential qualification for managing EHF patients with CRT. © 2011 Wiley Periodicals, Inc.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Mortality Trends for Non–ST‐segment Elevation Myocardial Infarction (NSTEMI) in the United States from 1988 to 2004
Authors: Movahed Mohammed Reza , John Jooby , Hashemzadeh Mehrnoosh , Hashemzadeh Mehrtash 
Published: November 2011

AbstractBackground:Non–ST‐segment myocardial infarction (NSTEMI) is one of the major causes of hospital admissions. Mortality trend in patients with NSTEMI over the years has not been studied well. The goal of this study is to explore age‐adjusted long‐term mortality trends from NSTEMI in the United States using a very large database.Methods:We used the National Inpatient Sample (NIS) database, a component of the Health Care Cost and Utilization (HCUP) project, for this study. International Classification of Disease, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes were used to identify NSTEMI cases in patients >40 years old. Age‐adjusted mortality rates for NSTEMI cases were calculated by multiplying the age‐specific mortality rates of NSTEMI by age‐specific weights.Results:A total of 1,400,234 patients above the age of 40 years were identified. The mean age of this cohort was 77.1±10.7 years, with a total of 179,361 deaths being reported over this 16‐year period. Among patients who died, 51.2% were men and 48.8% were women. The age‐adjusted mortality from NSTEMI declined from 1988 (727 per 100,000) to 2004 (305 per 100,000) until the middle of the decade when mortality from NSTEMI started leveling off. Total mortality decreased from 29.6% in 1988 to 11.3% in 2004.Conclusions:Our analysis showed a significant reduction in the age‐adjusted and total mortality for NSTEMI over the years studied. The cause of this trend is not known but most likely reflects advancement in the treatment of patients with acute coronary syndrome. © 2011 Wiley Periodicals, Inc.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Influence of mechanical defects on the crystal lattice of silicon
Authors: Jauß T. , Danilewsky A.N. , Wittge J. , Cröll A. , Garagorri J. , Elizalde R. M. , Allen D. , McNally P. 
Published: November 2011

AbstractTo examine the impact of mechanical defects on the crystal lattice of silicon, controlled damage was applied to silicon wafers by a nanoindendation method. With increasing loads of 1, 5 and 50 N, the area with micro‐cracks and strain around the indents increases. The damage is characterised by high resolution diffractometry using a conventional X‐ray tube. Spatially resolved rocking curves were recorded across the indents and analysed with respect to full width at half maximum. From reciprocal space maps the amount of strain and tilt around the indents is separated. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A mapping forwarding approach for supporting mobility in networks with identifier/locator separation
Authors: Qiu Feng , Luo Hongbin , Li Xiaoqian , Xue Miao , Dong Ping , Zhang Hongke 
Published: November 2011

SUMMARYThe identifier/locator separation has been widely recognized as a feasible solution for addressing the current Internet's routing scaling problem. Moreover, such a separation solution in terms of mobility can keep connection survivability and support global seamless roaming. A critical challenge in supporting efficient mobility is how to update the identifier‐to‐locator mappings of mobile nodes (MNs). In this paper, we propose a mapping forwarding (MF) scheme for location management in the identifier/locator separation architecture. In the MF scheme, a tunnel router (xTR) is selected as an agent of an MN and keeps the MN's identifier‐to‐locator mapping invariable by setting up an MF chain. As long as the MN is managed by the same xTR, the MN's mapping stored in the xTR of each correspondent node of the MN does not need to be updated, thus reducing the location update signaling cost. Meanwhile, the unchanged mapping assures the correct forwarding of packets, which reduces mobility‐related disruption and enhances the location management's reliability. In addition, for the handoff in two MF chains, we propose a data‐triggered update scheme that can achieve route optimization. To evaluate the proposed MF scheme, we establish two analytical models and formulate the blocking probability and the total protocol cost. The performance results show how the blocking probability changes under various parameters and how the MF scheme can effectively reduce the blocking probability compared with the location management scheme without the MF strategy. Meanwhile, our analysis demonstrates that the MF scheme has a lower overhead when the mobility rate is high. Copyright © 2011 John Wiley & Sons, Ltd.
Reducing code wastage in orthogonal variable spreading factor‐based wideband code division multiple access networks
Authors: Saini Davinder , Gupta Ankit , Joshi Aditi 
Published: November 2011

SUMMARYMost third‐generation and beyond wideband code division multiple access networks use the orthogonal variable spreading factor code tree for channelization codes. The codes in this code tree are limited and the performance of a wireless network depends upon the code assignment for new calls. In this paper, we introduce a term called ‘wastage capacity’, which gives us the amount of wastage caused when a code (single or multiple) with a data rate higher than the rate of the incoming call is assigned to it. We suggest two methods to keep wastage capacity below an arbitrary threshold value or zero. In the first method, we devised an algorithm in which wastage up to a certain threshold would be tolerated and the minimum rakes to get this wastage capacity were identified. In the second approach, we reduced the wastage capacity to zero irrespective of the number of rakes at the expense of higher cost and complexity. Copyright © 2011 John Wiley & Sons, Ltd.
A Quest for Ligand‐Unsupported Li+–π Interactions in Mono‐, Di‐, and Tritopic Lithium Arylborates
Authors: Franz Daniel , Haghiri Ilkhechi Alireza , Bolte Michael , Lerner Hans‐Wolfram , Wagner Matthias 
Published: November 2011

AbstractThe lithium salts of selected mono‐, di‐, and tritopic arylborates have been synthesized and their solid‐state structures have been analyzed by X‐ray crystallography with focus on the occurrence of Li+–aryl π interactions. The solvated salts of the monotopic arylborate [Li(thf)4][(p‐BrC6H4)BPh3] as well as the ditopic borates [Li(12‐crown‐4)2]2[p‐C6H4(BMe3)2] and [Li(tetraglyme)]2[p‐C6H4(BPh3)2] exist as solvent‐separated ion pairs in the crystal lattice. The attachment of two moderately coordinating monohydridoborate functionalities on a benzene ring leads to Li+–hydride interactions. In the case of [Li(thf)3]2[p‐C6H4{9‐BBN(H)}2] [9‐BBN(H) = 9‐borabicyclo[3.3.1]nonane], this additional attractive force is not sufficient to promote Li+–aryl π interactions, however, the 1,2‐dimethoxyethane (DME) solvate [Li(dme)2]2[p‐C6H4{9‐BBN(H)}2] shows a remarkably short contact between the Li+ cation and the adjacent phenylene ipso carbon atom [Li–C 2.366(2) Å]. The targeted structural motif ofLi+–arene η6 coordination was finally observed in the solid‐state structures of the tritopic borates [{Li(12‐crown‐4)2}2Li(thf)][1,3,5‐C6H3(BMe3)3] and [{Li(thf)2}2Li][1,3,5‐C6H3(BH3)3]. In the latter complex, an extensive network of Li–H–B bonds is observed in addition to the Li+–π interaction.