bluuebunny/crossref_metadata_2025_split huggingface dataset:
Na4IrO4: Square‐Planar Coordination of a Transition Metal in d5 Configuration due to Weak On‐Site Coulomb Interactions
Authors: Kanungo Sudipta , Yan Binghai , Merz Patrick , Felser Claudia , Jansen Martin 
Published: March 2015

AbstractLocal environments and valence electron counts primarily determine the electronic states and physical properties of transition‐metal complexes. For example, square‐planar coordination geometries found in transition‐metal oxometalates such as cuprates are usually associated with the d8 or d9 electron configuration. In this work, we address an unusual square‐planar single oxoanionic [IrO4]4− species, as observed in Na4IrO4 in which IrIV has a d5 configuration, and characterize the chemical bonding through experiments and by ab initio calculations. We find that the IrIV center in ground‐state Na4IrO4 has square‐planar coordination geometry because of the weak Coulomb repulsion of the Ir‐5d electrons. In contrast, in its 3d counterpart Na4CoO4, the CoIV center is tetrahedrally coordinated because of strong electron correlation. Na4IrO4 may thus serve as a simple yet important example to study the ramifications of Hubbard‐type Coulomb interactions on local geometries.
True Boundary for the Formation of Homoleptic Transition‐Metal Hydride Complexes
Authors: Takagi Shigeyuki , Iijima Yuki , Sato Toyoto , Saitoh Hiroyuki , Ikeda Kazutaka , Otomo Toshiya , Miwa Kazutoshi , Ikeshoji Tamio , Aoki Katsutoshi , Orimo Shin‐ichi 
Published: March 2015

AbstractDespite many exploratory studies over the past several decades, the presently known transition metals that form homoleptic transition‐metal hydride complexes are limited to the Groups 7–12. Here we present evidence for the formation of Mg3CrH8, containing the first Group 6 hydride complex [CrH7]5−. Our theoretical calculations reveal that pentagonal‐bipyramidal H coordination allows the formation of σ‐bonds between H and Cr. The results are strongly supported by neutron diffraction and IR spectroscopic measurements. Given that the Group 3–5 elements favor ionic/metallic bonding with H, along with the current results, the true boundary for the formation of homoleptic transition‐metal hydride complexes should be between Group 5 and 6. As the H coordination number generally tends to increase with decreasing atomic number of transition metals, the revised boundary suggests high potential for further discovery of hydrogen‐rich materials that are of both technological and fundamental interest.
Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales
Authors: Janeček Emma‐Rose , McKee Jason R. , Tan Cindy S. Y. , Nykänen Antti , Kettunen Marjo , Laine Janne , Ikkala Olli , Scherman Oren A. 
Published: March 2015

AbstractHybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl‐functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross‐linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross‐linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.
Thermal properties and degradation behavior of poly(1,4‐butylene adipate)/modified layered double hydroxide nanocomposites
Authors: Chu Mei‐Chen , Hang Yi‐Tong , Chen Yi‐An , Wu Tzong‐Ming 
Published: March 2015

ABSTRACTIn this study, poly(1,4‐butylene adipate) (PBA)/organomodified layered double hydroxide (m‐LDH) nanocomposites were synthesized and characterized as a new material for green materials use. m‐LDH was initially prepared with magnesium nitrate hexahydrate, aluminum nitrate‐9‐hydrate, oleic acid, and sorbitol by a novel one‐step coprecipitation method to intercalate the oleic acid and sorbitol organomodifier into the interlayer of the layered double hydroxide. The solution mixing process was then applied and shown to be an efficient method for fabricating the PBA/m‐LDH nanocomposites. The m‐LDH characterized by X‐ray diffraction (XRD) showed a high interlayer spacing of 58.8 Å. The morphology and thermal properties of the PBA/m‐LDH nanocomposites were characterized with XRD, transmission electron microscopy, and thermogravimetric analysis. It was shown that the m‐LDH was well distributed in the PBA matrix and that the thermal properties of the PBA/m‐LDH nanocomposites significantly improved with a loading of 0.1 wt % m‐LDH. Finally, the biodegradability of the PBA/m‐LDH nanocomposites was tested with lipase from Pseudomonas fluorescens as a microbial catalyst. It was shown that an addition of m‐LDH up to 0.5% resulted in a significant difference in terms of the biodegradability. After 120 h of degradation, the residual weight and surface morphology of the composite films were affected by the presence of m‐LDH. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42083.
Characteristics of Fibromyalgia Independently Predict Poorer Long‐Term Analgesic Outcomes Following Total Knee and Hip Arthroplasty
Authors: Brummett Chad M. , Urquhart Andrew G. , Hassett Afton L. , Tsodikov Alex , Hallstrom Brian R. , Wood Nathan I. , Williams David A. , Clauw Daniel J. 
Published: March 2015

ObjectiveWhile psychosocial factors have been associated with poorer outcomes after knee and hip arthroplasty, we hypothesized that augmented pain perception, as occurs in conditions such as fibromyalgia, may account for decreased responsiveness to primary knee and hip arthroplasty.MethodsA prospective, observational cohort study was conducted. Preoperative phenotyping was conducted using validated questionnaires to assess pain, function, depression, anxiety, and catastrophizing. Participants also completed the 2011 fibromyalgia survey questionnaire, which addresses the widespread body pain and comorbid symptoms associated with characteristics of fibromyalgia.ResultsOf the 665 participants, 464 were retained 6 months after surgery. Since individuals who met criteria for being classified as having fibromyalgia were expected to respond less favorably, all primary analyses excluded these individuals (6% of the cohort). In the multivariate linear regression model predicting change in knee/hip pain (primary outcome), a higher fibromyalgia survey score was independently predictive of less improvement in pain (estimate −0.25, SE 0.044; P < 0.00001). Lower baseline joint pain scores and knee (versus hip) arthroplasty were also predictive of less improvement (R2 = 0.58). The same covariates were predictive in the multivariate logistic regression model for change in knee/hip pain, with a 17.8% increase in the odds of failure to meet the threshold of 50% improvement for every 1‐point increase in fibromyalgia survey score (P = 0.00032). The fibromyalgia survey score was also independently predictive of change in overall pain and patient global impression of change.ConclusionOur findings indicate that the fibromyalgia survey score is a robust predictor of poorer arthroplasty outcomes, even among individuals whose score falls well below the threshold for the categorical diagnosis of fibromyalgia.
Association of Severe Disc Degeneration With All‐Cause Mortality and Abdominal Aortic Calcification Assessed Prospectively in Older Men: Findings of a Single‐Center Prospective Study of Osteoporosis in Men
Authors: Estublier Charline , Chapurlat Roland , Szulc Pawel 
Published: March 2015

ObjectiveTo assess the association of disc degeneration with all‐cause mortality and with the severity and rate of progression of abdominal aortic calcification (AAC) in older men.MethodsMen >50 years of age (n = 766) underwent lateral spine radiography and blood collection and were monitored prospectively. We assessed the association of disc degeneration with all‐cause mortality (at 10 years), AAC severity (at baseline), and AAC progression (at 7.5 years).ResultsAfter adjustment for confounders, including AAC, the total overall grade score for AAC predicted all‐cause mortality (hazard ratio [HR] 1.20 per SD increase [95% confidence interval (95% CI) 1.01–1.43]). The highest tertile of the total overall grade score was associated with higher mortality rates (39.3/1,000 person‐years for a score of >8 versus 20.9/1,000 person‐years for a score of 0–8; adjusted HR 1.47 [95% CI 1.05–2.06]). The odds of severe AAC (score of >5) increased with the total disc space narrowing score (adjusted HR 1.44 per SD [95% CI 1.11–1.87]). The highest tertile of the total disc space narrowing score was associated with higher odds of severe AAC (adjusted HR 2.42 versus the lowest tertile [95% CI 1.24–4.73]). The probability of long‐term AAC stability decreased with an increasing total osteophyte score (adjusted HR 0.66 per SD [95% CI 0.49–0.88]). The highest tertile of the total osteophyte score was associated with a lower probability of AAC stability (adjusted HR 0.35 versus the lowest tertile [95% CI 0.18–0.71]).ConclusionOlder men with severe disc dege‐neration have greater AAC severity, faster AAC progression, and higher all‐cause mortality rates.
Customer Environmental Values and Their Contribution to Loyalty in Industrial Markets
Authors: Mustonen Nora , Karjaluoto Heikki , Jayawardhena Chanaka 
Published: March 2015

AbstractConcern over the effect of industries on the natural environment is growing on a multitude of levels. This study examines the effects of how perceptions of (a) environmental values, (b) green image and (c) perceived value of industrial customers influence their loyalty towards suppliers in existing relationships, and how the length of B2B relationships may moderate these linkages. A conceptual framework is developed and data are collected from a global sample (N =121) of B2B customers. We find that both green image and perceived value have a direct positive link with customer loyalty and that environmental values are positively linked to the green image of the supplier. Moreover, the effect of green image on loyalty is mediated by perceived value, with environmental values only indirectly linked with perceived value of the supplier. As the length of relationship increases, on one hand the positive relationship between green image and customer loyalty is strengthened, while on the other the positive relationship between environmental value and green image is weakened. Regardless of how environmentally aware the customer is, green image is a strong predictor of both perceived value and loyalty. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment
Drimane Sesquiterpenoids from the Aspergillus oryzae QXPC‐4
Authors: Ren Ren , Chen Chao‐Jun , Hu Sha‐Sha , Ge Hui‐Ming , Zhu Wen‐Yong , Tan Ren‐Xiang , Jiao Rui‐Hua 
Published: March 2015

AbstractThree new drimane sesquiterpenoids, astellolides C–E (1–3, resp.), four new drimane sesquiterpenoid p‐hydroxybenzoates, astellolides F–I (4–7, resp.), together with two known compounds astellolides A and B (8 and 9, resp.), have been isolated from the liquid culture of Aspergillus oryzae (strain No. QXPC‐4). Their structures were established by comprehensive analysis of spectroscopic data. The relative and absolute configurations were determined on the basis of NOESY and CD data, together with single‐crystal X‐ray diffraction analyses of compounds 1–3. The metabolites were evaluated for their cytotoxic activities, however, no compounds showed a significant cytotoxicity against the tested cell lines at a concentration of 20 μM.
Biochemical Characterization of Helichrysum italicum (Roth) G.Don subsp. italicum (Asteraceae) from Montenegro: Phytochemical Screening, Chemotaxonomy, and Antioxidant Properties
Authors: Kladar Nebojša V. , Anačkov Goran T. , Rat Milica M. , Srđenović Branislava U. , Grujić Nevena N. , Šefer Emilia I. , Božin Biljana N. 
Published: March 2015

AbstractThe chemical composition and antioxidant properties of the essential oil and EtOH extract of immortelle (Helichrysum italicum (Roth) G.Don subsp. italicum, Asteraceae) collected in Montenegro were evaluated. The essential oil was characterized by GC/MS analysis, and the content of total phenolics and flavonoids in the EtOH extract was determined using the FolinCiocalteu reagent. The free‐radical‐scavenging capacity (RSC) of both the essential oil and the EtOH extract was assessed with the 2,2‐diphenyl‐1‐pycrylhydrazyl (DPPH) method. Moreover, the inhibition of hydroxyl radical (.OH) generation by the EtOH extract of immortelle was evaluated for the first time here. Neryl acetate (28.2%) and γ‐curcumene (18.8%) were the main compounds in the essential oil, followed by neryl propionate (9.1%) and ar‐curcumene (8.3%). The chemical composition of the oils of the examined and additional 16 selected Helichrysum italicum taxa described in literature were compared using principal component (PCA) and cluster (CA) analyses. The results of the statistical analyses implied the occurrence of at least four different main and three subchemotypes of essential oils. Considering the antioxidant properties, the EtOH extract of immortelle exhibited similar potential as propyl gallate and quercetin, while the essential oil exhibited relatively weak DPPH.‐scavenging capacity.
Presynaptic architecture of the larval zebrafish neuromuscular junction
Authors: Helmprobst Frederik , Frank Miriam , Stigloher Christian 
Published: March 2015

ABSTRACTThis article shows the ultrastructural architecture of larval zebrafish (Danio rerio) neuromuscular junctions in three dimensions. We compare classical electron microscopy fixation techniques with high‐pressure freezing followed by freeze substitution (HPF/FS) in combination with electron tomography. Furthermore, we compare the structure of neuromuscular junctions in 4‐ and 8‐dpf zebrafish larvae with HPF/FS because this allows for close‐to‐native ultrastructural preservation. We discovered that synaptic vesicles of 4‐dpf zebrafish larvae are larger than those of 8‐dpf larvae. Furthermore, we describe two types of dense‐core vesicles and quantify a filamentous network of small filaments interconnecting synaptic vesicles as well as tethers connecting synaptic vesicles to the presynaptic cell membrane. In the center of active zones, we found elaborate electron‐dense projections physically connecting vesicles of the synaptic vesicle pool to the presynaptic membrane. Overall this study establishes the basis for systematic comparisons of synaptic architecture at high resolution in three dimensions of an intact vertebrate in a close‐to‐native state. Furthermore, we provide quantitative information that builds the basis for diverse systems biology approaches in neuroscience, from comparative anatomy to cellular simulations. J. Comp. Neurol. 523:1984–1997, 2015 © 2015 Wiley Periodicals, Inc.
Tracing vocal fold vibrations using level set segmentation method
Authors: Shi Tailong , Kim Hyun June , Murry Thomas , Woo Peak , Yan Yuling 
Published: March 2015

SummaryHigh‐speed digital imaging (HSDI) of the larynx can provide important information on the vocal fold kinematics. This information is useful and may provide a better understanding of the mechanism of phonation and assist clinical assessment of voice disorders. Automatic tracing of the vocal fold vibration is a key step in the kinematic analysis and for correlative characterization of vocal fold vibrations and voice quality in normal and diseased states. In this study, we introduce a new approach for image segmentation and automatic tracing of vocal fold motion that combines the level set method and motion cue. This approach is applied to videokymogram (VKG)‐form images, which are obtained from a sequence of laryngeal images captured using the HSDI. To utilize the motion cue for a more effective level set based segmentation on the VKG, we first construct a so‐called standard deviation (STD) image by mapping the pixel‐based measure of temporal intensity dispersion from the initial HSDI sequence. The STD image maps the extent of vocal fold motion, and followed by threshold operation, a region of interest (ROI) that encloses vocal fold motion, or glottal region, is identified. The performance and effectiveness of our approach are evaluated by using clinical datasets representing both normal and pathological voice conditions. Copyright © 2015 John Wiley & Sons, Ltd.
Development of Ionic Liquids Tethered to Coconut Shell Activated Carbon for Biogas Upgrading in a Packed Bed
Authors: Wang Lei , Zhang Junning , Tan Ziting , Jiang Hong , Xiong Chunrong 
Published: March 2015

AbstractIonic liquids (ILs) were prepared in situ successfully on coconut shell activated carbon (AC) granules for biogas upgrading in a packed bed. In biogas upgrading, the saturated CO2 capture capacities of AC‐tethered 1‐butyl‐3‐propylimidazolium bis(trifluoromethylsulfonyl)imide (AC‐[BPIM][Tf2N]) and AC‐tethered 1‐aminoethyl‐3‐propylimidazolium bis(trifluoromethylsulfonyl)imide (AC‐[EPIM‐NH2][Tf2N]) were 2.58 and 2.95 mmol g−1 at 20 °C and 0.5 MPa, respectively. The heat of adsorption was 23–28 kJ mol−1 for AC‐[BPIM]‐based adsorbents and 65–71 kJ mol−1 for AC‐[EPIM‐NH2]‐based ones. As a CO2 concentration of less than 3 % is required for biogas to be used in a vehicle, an adsorption capacity at which 3 % of CO2 is reached in the upgraded gas could be more important. If the flow rate of the inlet gas was 50 mL min−1, the adsorption capacity at which 3 % of CO2 is reached in the upgraded gas was 1.44 mmol g−1 for AC‐[BPIM][Tf2N] and 1.95 mmol g−1 for AC‐[EPIM‐NH2][Tf2N] at 20 °C and 0.2 MPa. The adsorption selectivities of CO2 over CH4 were ∼92 and 95 % for AC‐[BPIM][Tf2N] and AC‐[EPIM‐NH2][Tf2N], respectively. The immobilized ILs exhibited a relatively stable cyclability in a packed bed.
Hydrogen Transfer of Petroleum Residue Subfractions During Thermal Processing under Hydrogen
Authors: Wang Zongxian , Ji Shunfeng , Liu He , Chen Kun , Guo Aijun 
Published: March 2015

AbstractAnthracene (ANT) was applied as the accepting probe to evaluate the hydrogen transfer ability of a Venezuela petroleum residue and its subfractions (i.e., saturates, aromatics, resins, and asphaltenes) under different atmospheres and reaction conditions. The hydrogen donating ability (HDA) of H2, HDA of the fractions, and synergism between fractions and H2 were analyzed. The results show that the temperature, initial hydrogen pressure, and time have a positive effect on the HDA of hydrogen. The HDA of all of the subfractions increases clearly with increasing temperature, both under nitrogen and hydrogen, before an equilibrium is achieved, and the HDA determined under hydrogen is higher than that measured under nitrogen. The saturates (Sa) and aromatics (Ar) showed a positive synergism with hydrogen, whereas the resins (Re) and asphaltenes (Asp) showed a negative one according to the calculated synergism. The summation HDA determined under nitrogen was significantly lower than the original HDA of the Venezuela petroleum residue, whereas the trend for hydrogen was the opposite.
Accurate real‐time hybrid earthquake simulations on large‐scale MDOF steel structure with nonlinear viscous dampers
Authors: Dong Baiping , Sause Richard , Ricles James M. 
Published: March 2015

SummaryThis paper presents real‐time hybrid earthquake simulation (RTHS) on a large‐scale steel structure with nonlinear viscous dampers. The test structure includes a three‐story, single‐bay moment‐resisting frame (MRF), a three‐story, single‐bay frame with a nonlinear viscous damper and associated bracing in each story (called damped braced frame (DBF)), and gravity load system with associated seismic mass and gravity loads. To achieve the accurate RTHS results presented in this paper, several factors were considered comprehensively: (1) different arrangements of substructures for the RTHS; (2) dynamic characteristics of the test setup; (3) accurate integration of the equations of motion; (4) continuous movement of the servo‐controlled hydraulic actuators; (5) appropriate feedback signals to control the RTHS; and (6) adaptive compensation for potential control errors. Unlike most previous RTHS studies, where the actuator stroke was used as the feedback to control the RTHS, the present study uses the measured displacements of the experimental substructure as the feedback for the RTHS, to enable accurate displacements to be imposed on the experimental substructure. This improvement in approach was needed because of compliance and other dynamic characteristics of the test setup, which will be present in most large‐scale RTHS. RTHS with ground motions at the design basis earthquake and maximum considered earthquake levels were successfully performed, resulting in significant nonlinear response of the test structure, which makes accurate RTHS more challenging. Two phases of RTHS were conducted: in the first phase, the DBF is the experimental substructure, and in the second phase, the DBF together with the MRF is the experimental substructure. The results from the two phases of RTHS are presented and compared with numerical simulation results. An evaluation of the results shows that the RTHS approach used in this study provides a realistic and accurate simulation of the seismic response of a large‐scale structure with rate‐dependent energy dissipating devices. Copyright © 2015 John Wiley & Sons, Ltd.
Joint isotopic mass balance: a novel approach to quantifying channel bed to channel margins sediment transfer during storm events
Authors: Underwood John W. , Renshaw Carl E. , Magilligan Francis J. , Dade W. Brian , Landis Joshua D. 
Published: March 2015

AbstractThe important role of floodplains and the broader riparian zone in providing temporary storage for a large fraction of the annual sediment load of rivers is well established, but this understanding is largely based on observations of the long‐term average behavior of the catchment. Here we combine measurements of the fallout radionuclides 7Be and 210Pb and the stable isotopes of hydrogen in water to quantify fine sediment mobilization and storage in a stream and its channel margins during individual intermediate‐sized storm events with recurrence intervals of a few months or less. We demonstrate this method using five storm events in a small (~15 km2), undeveloped, gravel‐bedded tributary of the Connecticut River (USA). We estimate that in each storm, the mass of sediment deposited onto the margins accounts for almost 90% of the sediment mobilized from the bed, with the remainder of the mobilized bed sediment transported downstream as suspended load. The result that the bed is a net source of sediment to the stream and the margins a net sink is robust, but estimates of the mass of material eroded from the bed and deposited on the margins are less certain. The source of sediment to the bed remains unclear as, consistent with earlier studies, we observe only limited deposition of sediment to the bed during the storm events. The suspended sediment is organic‐rich and thus its source may be associated with in‐channel organic decay between storm events. Understanding the coupled interactions between discharge magnitude and frequency and sediment resupply at the event time scale has important implications for stream restoration efforts seeking to connect the channel and the broader riparian zone, and for the development of accurate sediment budgets and predictions of sediment flux from a watershed. Copyright © 2015 John Wiley & Sons, Ltd.