bluuebunny/crossref_metadata_2025_split huggingface dataset:
A knowledge‐based web platform for collaborative physical system modeling and simulation
Authors: Yanshan Zhang , Fah Yap Fook , Singh Jasleen , Ting Lei , Lei Gao 
Published: March 2013

AbstractA web platform, called Proteus (http://www.visualphysics.net/pweb), has been developed by a team in Nanyang Technological University. This platform is designed for education and academic research, and is free to use. It provides a place where students, educators, and academic researchers can easily create and share their computer models of physical systems described using Modelica, a non‐proprietary, object‐oriented, equation‐based language for physical system modeling. It comes with a web‐based, graphical modeling, and simulation tool called ProteusGWT (http://www.visualphysics.net/ProteusGWT). ProteusGWT is web‐based and uses an intuitive, graphical component‐oriented approach to the modeling of physical systems spanning multiple domains including systems containing mechanical, hydraulic, thermal, control, electrical, electronic, electric power, or process‐oriented subcomponents. It synthesizes state‐of‐the‐art web technologies (e.g., HTML5, GWT, and cloud computing), computational methods for physical systems modeling, and simulation to create a computing environment that is widely deployable and scalable. Google Web Toolkit (GWT) is a development toolkit from Google for building and optimizing complex web‐based applications. It allows developers to create and maintain complex JavaScript applications in Java language. Proteus allows anyone with a computer or browser‐enabled device to be able to use it. Hence, anyone can contribute their computer models of physical systems to this platform. As this platform grows, it could turn out to be an online interactive repository for all kinds of physical system models, for example, a student may examine complete computer models of a motorcycle, a refrigerator, a burglar alarm, or robot arm and learn about how they work. He or she could run simulations, modify the models, or create new designs and share with others. There is nothing quite like this currently on the Internet. © 2013 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:23–35, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21572
Spectroscopic and Theoretical Study on Electronically Modified Chromophores in LOV Domains: 8‐Bromo‐ and 8‐Trifluoromethyl‐Substituted Flavins
Authors: Mansurova Madina , Simon Julian , Salzmann Susanne , Marian Christel M. , Gärtner Wolfgang 
Published: March 2013

AbstractTwo chemically synthesized flavin derivatives, 8‐trifluoromethyl‐ and 8‐bromoriboflavin (8‐CF3RF and 8‐BrRF), were photochemically characterized in H2O and studied spectroscopically after incorporation into the LOV domain of the blue light photoreceptor YtvA from Bacillus subtilis. The spectroscopic studies were paralleled by high‐level quantum chemical calculations. In solution, 8‐BrRF showed a remarkably high triplet quantum yield (0.97, parent compound riboflavin, RF: 0.6) and a small fluorescence quantum yield (0.07, RF: 0.27). For 8‐CF3RF, the triplet yield was 0.12, and the fluorescence quantum yield was 0.7. The high triplet yield of 8‐BrRF is due to the bromine heavy atom effect causing a stronger spin–orbit coupling. Theoretical calculations reveal that the decreased triplet yield of 8‐CF3RF is due to a smaller charge transfer and a less favorable energetic position of T2, required for intersystem crossing from S1 to T1, as an effect of the electron‐withdrawing CF3 group. The reconstitution of the LOV domain with the new flavins resulted in the typical LOV photochemistry, consisting of triplet state formation and covalent binding of the chromophore, followed by a thermal recovery of the parent state, albeit with different kinetics and photophysical properties.
Laccase‐Catalyzed CS and CC Coupling for a One‐Pot Synthesis of 1,4‐Naphthoquinone Sulfides and 1,4‐Naphthoquinone Sulfide Dimers
Authors: Wellington Kevin W. , Gordon Gregory E. R. , Ndlovu Lindelani A. , Steenkamp Paul 
Published: March 2013

AbstractOxidative CS and CC bond formation with aryl and alkyl thiols was catalyzed under mild conditions in a reaction vessel open to air at pH 4.5 in the presence of a commercial laccase (Novozym 51003 or Suberase) and a cosolvent (DMF) to afford 1,4‐naphthoquinone sulfides. Although both monothiolation and dithiolation of the 1,4‐naphthohydroquinone were accomplished, the latter was favored. In addition, unprecedented dimerization of monothiolated intermediates occurred through CC coupling. These commercial laccases provide a facile and a more environmentally friendly synthetic approach to both 1,4‐naphthoquinone sulfides and 1,4‐naphthoquinone sulfide dimers.
Compositional and Morphological Changes of Ordered PtxFey/C Oxygen Electroreduction Catalysts
Authors: Chen Liang , Chan Mickey C. Y. , Nan Feihong , Bock Christina , Botton Gianluigi A. , Mercier Patrick H. J. , MacDougall Barry R. 
Published: March 2013

AbstractChanges in the O2 reduction activity (ORR) and structure of carbon‐supported catalysts upon electrochemical stress testing are investigated. Focus is placed on two alloy catalysts of nominal Pt3Fe/C and Pt3Fe2/C compositions. Energy dispersive X‐ray spectroscopy (EDXS) spot and line analyses reveal a dependence of the Fe composition on the particle size, particularly for the two as‐prepared catalysts. The catalyst particles are shown to have a Pt‐enriched shell and a PtxFey alloy core. Larger (>≈10 nm) particles are shown to have a higher Fe content that approaches the nominal composition, which suggests that the smaller (<≈6 nm) Pt catalyst particles are more difficult to alloy. High‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM), XRD, and SEM with EDXS show that Fe is lost gradually from the catalyst particles as a result of extensive potential (E)‐cycling. Changes upon E‐cycling are observed most clearly for the small (<3 nm) particles, in which Fe is almost entirely depleted. However, the catalytic ORR activities remain constant over an extensive cycling period for the PtxFey/C catalysts and the mass ORR activities decrease proportionally with Pt surface area (APt). The histograms before and after cycling are compared to observed changes in APt and are discussed in comparison to E‐holding experiments. It is concluded that the dissolution of Pt is a strong contributor for the observed decrease in APt and mass ORR activity for the PtxFey/C catalysts. The continuous transition between Pt oxide formation and its reduction to Pt metal is suggested to play a major role in the degradation of the PtxFey/C catalysts studied in this work.
Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5‐Chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic Acid
Authors: Liu Hong , Liu Chongbo , Gong Yunnan , Wang Yuhua , Wen Huiliang 
Published: March 2013

AbstractFive new transition metal complexes [Cu(HL)2(H2O)2] (1), [Cu(HL)2(phen)] (2), [Cu(HL)2(H2O)]2(4,4′‐bipy) (3), [Zn(HL)2(H2O)2]·(4,4′‐bipy) (4), [Ag(HL)(4,4′‐bipy)]n (5), (H2L=5‐chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid, phen=1,10‐phenanthroline; 4,4′‐bipy=4,4′‐bipyridine) have been synthesized and characterized. Complexes 1, 2 and 4 exhibit monomeric structures, 3 shows a dinuclear structure, 5 displays 1D chain structure, and all extend to 3D supramolecular network via rich hydrogen bonds. Complexes 1, 2, 3, 5 comprise single helical chains, while complex 4 generates quadruple‐stranded helical chains. Furthermore, the antibacterial activities of the titled complexes against bacterial species, three Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis and Candida albicans) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were studied and compared to the activities of free ligands by using the microdilution method.
External validation of a prognostic nomogram for overall survival in women with uterine leiomyosarcoma
Authors: Iasonos Alexia , Keung Emily Z. , Zivanovic Oliver , Mancari Rosanna , Peiretti Michele , Nucci Marisa , George Suzanne , Colombo Nicoletta , Carinelli Silvestro , Hensley Martee L. , Raut Chandrajit P. 
Published: March 2013

AbstractBACKGROUND:There is no validated system to identify prognostically distinct cohorts of women with uterine leiomyosarcoma (ULMS). By using an independent, pooled, multi‐institutional, international patient cohort, the authors validated a recently proposed ULMS nomogram.METHODS:The ULMS nomogram incorporated 7 clinical characteristics (age, tumor size, tumor grade, cervical involvement, locoregional metastases, distant metastases, and mitotic index (per 10 high‐power fields) to predict overall survival (OS) after primary surgery. Independent cohorts from 2 sarcoma centers were included. Eligible women, at minimum, underwent a hysterectomy for primary, locally advanced, or metastatic ULMS and received part of their care at 1 of the centers between 1994 and 2010.RESULTS:In total, 187 women with ULMS were identified who met the above criteria described above (median age, 51 years; median tumor size, 9 cm; median mitotic index, 20 per 10 high‐power fields). Tumors generally were high grade (88%), FIGO stage I or II (61%) without cervical involvement (93%) and without locoregional metastases (77%) or distant metastases (83%). The median OS and the 5‐year OS rate were 4.5 years (95% confidence interval, 3.2‐5.3 years) and 46%, respectively; and 65 women (35%) remained alive at last follow‐up. The nomogram concordance index was 0.67(standard error, 0.02), which was as high as the concordance index from the initial cohort used for nomogram development. The concordance between actual OS and nomogram predictions suggests excellent calibration because predictions were within 1% of actual 5‐year OS rates for patients with a predicted 5‐year OS of less than 0.68.CONCLUSIONS:The ULMS nomogram was externally validated using independent cohorts. These findings support the international use of the ULMS nomogram prognostic of OS in ULMS. Cancer 2013. © 2012 American Cancer Society.
Hospital volume is associated with survival but not multimodality therapy in Medicare patients with advanced head and neck cancer
Authors: Sharma Arun , Schwartz Stephen M. , Méndez Eduardo 
Published: March 2013

AbstractBACKGROUND:Given the complexity of management of advanced head and neck squamous cell carcinoma (HNSCC), this study hypothesized that high hospital volume would be associated with receiving National Comprehensive Cancer Network (NCCN) guideline therapy and improved survival in patients with advanced HNSCC.METHODS:The Surveillance, Epidemiology, and End Results (SEER)‐Medicare database was used to identify patients with advanced HNSCC. Treatment modalities and survival were determined using Medicare data. Hospital volume was determined by the number of patients with HNSCC treated at each hospital.RESULTS:There were 1195 patients with advanced HNSCC who met inclusion criteria. In multivariable analyses, high hospital volume was not associated with receiving multimodality therapy per NCCN guidelines (odds ratio = 1.02, 95% confidence interval = 0.66‐1.60), but showed a nearly significant inverse association with survival in a model adjusted for National Cancer Institute–designated cancer center status, age, sex, race, socioeconomic status, marital status, comorbidity, year of diagnosis, tumor site, and tumor stage (hazard ratio = 0.85, 95% confidence interval = 0.69‐1.04).CONCLUSIONS:Medicare patients with advanced HNSCC treated at high‐volume hospitals were not more likely to receive NCCN guideline therapy, but had nearly statistically significant better survival, when compared with patients treated at low‐volume hospitals. These results suggest that features of high‐volume hospitals other than delivery of NCCN guideline therapy influence survival. Cancer 2013. © 2013 American Cancer Society.
Prognostic impact of absolute lymphocyte counts at the end of remission induction in childhood acute lymphoblastic leukemia
Authors: Rubnitz Jeffrey E. , Campbell Patrick , Zhou Yinmei , Sandlund John T. , Jeha Sima , Ribeiro Raul C. , Inaba Hiroto , Bhojwani Deepa , Relling Mary V. , Howard Scott C. , Campana Dario , Pui Ching‐Hon 
Published: March 2013

BACKGROUNDAbsolute lymphocyte counts (ALC) during treatment have been associated with outcome in children and adults with hematologic malignancies. However, the impact of ALC relative to that of other prognostic factors on the outcome of children with acute lymphoblastic leukemia (ALL) treated in recent trials is unknown.METHODSOutcomes of 399 patients aged ≤18 years with newly diagnosed ALL who were enrolled in the Total Therapy XV study at St. Jude Children's Research Hospital were analyzed according to ALC at the end of remission induction therapy.RESULTSAn ALC ≥500 cells/μL was significantly more prevalent among patients with B‐lineage ALL, in those with favorable presenting features, and in those who achieved negative minimal residual disease (MRD) status on day 43 of treatment. Both overall survival (OS) and event‐free survival (EFS) were superior among patients with higher ALC, but only the association with OS was statistically significant in a univariate analysis. In multivariable analyses, ALC was not a significant predictor of outcome after controlling for age, leukocyte count, lineage, risk group, and MRD status at the end of induction (P > .1 for all comparisons). However, among MRD‐negative patients, those with low ALC had a 5‐year OS rate of 84.2% ± 8.9% versus 97.3% ± 1.0% for patients with higher ALC (P = .036).CONCLUSIONSALC at the end of induction is related to favorable presenting features and good initial treatment response but does not independently predict outcome in the context of contemporary, MRD‐guided therapy. Cancer 2013;119:2061–2066. © 2013 American Cancer Society.
Self‐organizing market structures, system dynamics, and urn theory
Authors: Buendía Fernando 
Published: March 2013

AbstractUsing data from Fortune Magazine's 500 American largest corporations from 1955 to 2010, this article shows that firm sizes at national and industrial level are highly skew but not Zipf‐distributed. It also argues that, while self‐organizing industrial structures of this kind are due to increasing returns and hard to describe with conventional theories, system dynamics and urn theory are equipped with adequate tools to analyze them.
Rhenium Complexes with a Pyridinyl‐Naphthyridine Ligand: Synthesis, Characterization, and Catalytic Activity
Authors: Su Tzu‐Chieh , Liu Yi‐Hung , Peng Shie‐Ming , Liu Shiuh‐Tzung 
Published: March 2013

AbstractTreatment of [Re2(CO)8(CH3CN)2] with 2,7‐dipyridinyl‐1,8‐naphthyridine (bpnp) thermally provided mononuclear [(N,N′‐bpnp)Re(CO)3Cl] (1). Further reaction of 1 with rhenium carbonyls yielded ortho‐metallation dinuclear rhenium complex 2. Both complexes were characterized by spectroscopic analyses and single‐crystal X‐ray determination. Complex 1 also reacted with [PdMeCl(COD)] and [Ir(COD)Cl]2 by means of ortho‐metallation to yield the corresponding heterodinuclear species. Complex 2 appears to be an excellent precatalyst to promote the insertion of terminal alkynes into acetoacetates, which subsequently undergo cyclization to form 2‐pyranones.
Iron‐Catalyzed Reduction of Carboxylic Esters to Alcohols
Authors: Junge Kathrin , Wendt Bianca , Zhou Shaolin , Beller Matthias 
Published: March 2013

AbstractA novel catalytic system formed from Fe(stearate)2/NH2CH2CH2NH2 and polymethylhydrosiloxane was directly developed for the hydrosilylation of carboxylic acid esters to alcohols. The catalytic method exhibits broad substrate scope, including 20 aliphatic, aromatic, and heterocyclic esters. The corresponding alcohols are obtained in moderate to very good yields.
Stereoselective Synthesis of Substituted 1,4‐Oxazepanes by Intramolecular Reductive Etherification
Authors: Gharpure Santosh J. , Prasad J. V. K. 
Published: March 2013

AbstractA facile and general strategy is developed for the stereoselective synthesis of substituted 1,4‐oxazepane derivatives through an intramolecular reductive etherification reaction. The effects of the substituents present on the oxonium ion and the position of this ion with respect to the nitrogen atom on the yield and selectivity of the reaction are also studied.
Electrochemical Performance of All‐Solid‐State Li/S Batteries with Sulfur‐Based Composite Electrodes Prepared by Mechanical Milling at High Temperature
Authors: Nagao Motohiro , Hayashi Akitoshi , Tatsumisago Masahiro 
Published: March 2013

AbstractSulfur–nanocarbon composites were prepared by mechanical milling at high temperature (155 °C), and the electrochemical performance of all‐solid‐state Li/S batteries was investigated with Li2S–P2S5 solid electrolytes . We aimed to increase the sulfur content in the sulfur‐based composite electrodes to enhance the energy density in the Li/S batteries. The composites included 50 wt % sulfur, which is twice as high as that in the all‐solid‐state Li/S batteries that use sulfide‐based solid electrolytes reported to date, and high‐temperature mechanical milling resulted in a small sulfur particle size with a large contact area between the particles. The improved composites are mainly responsible for the excellent cyclability (1050 mAh g−1 for 50 cycles), high gravimetric energy density (1007 Wh kg−1), and good rate capability of the assembled batteries. These composites are promising positive‐electrode materials for rechargeable Li/S batteries with high energy density. This approach of mechanical milling at high temperature is widely applicable and can be extended to a variety of materials in versatile energy devices as well as rechargeable lithium batteries.
Optimal Economic Design of an Extractive Distillation Process for Bioethanol Dehydration
Authors: Kiss Anton A. , Ignat Radu M. 
Published: March 2013

AbstractThe large‐scale production of bioethanol fuel requires energy‐demanding distillation steps to concentrate the diluted product streams from the fermentation step and to overcome the azeotropic behavior of the ethanol‐water mixture. The conventional separation sequence consists of three distillation columns performing several tasks with high energy penalties: preconcentration of ethanol (PDC), extractive distillation (EDC) and solvent recovery (SRC). It is remarkable that almost all papers on this topic focus on the azeotropic separation only, neglecting the preconcentration step. The energy usage in the PDC increases as the distillate composition gets closer to the azeotrope, and the energy requirements in the EDC and SRC units decrease as the input stream to the EDC becomes richer in ethanol and vice versa. In this study we optimize the economics and energy consumption of a PDC as a function of the distillate composition, a fundamental issue that was not investigated before. Simulations were conducted using Aspen Plus to investigate how this parameter affects the energy usage and investment costs of the complete system. This procedure applies as well to other processes that contain a preconcentration column (e.g., extractive and azeotropic distillation). The optimal economic conditions are reached at a distillate concentration of 91 wt % (80 mol %) ethanol, for which the specific energy consumption is 2.11 kWh (7596 kJ) per kg ethanol.
Habitat-specific foraging and sex determine mercury concentrations in sympatric benthic and limnetic ecotypes of threespine stickleback
Authors: Willacker James J. , von Hippel Frank A. , Ackerly Kerri L. , O'Hara Todd M. 
Published: March 2013

Abstract

Mercury (Hg) is a widespread environmental contaminant known for the neurotoxicity of its methylated forms, especially monomethylmercury, which bioaccumulates and biomagnifies in aquatic food webs. Mercury bioaccumulation and biomagnification rates are known to vary among species utilizing different food webs (benthic vs limnetic) within and between systems. The authors assessed whether carbon and nitrogen stable isotope values and total Hg (THg) concentrations differed between sympatric benthic and limnetic ecotypes and sexes of threespine stickleback fish (Gasterosteus aculeatus) from Benka Lake, Alaska, USA. The mean THg concentration in the limnetic ecotype was significantly higher (difference between benthic and limnetic means equals 26 mg/kg dry wt or 16.1%) than that of the benthic ecotype. Trophic position and benthic carbon percentage utilized were both important determinants of THg concentration; however, the 2 variables were of approximately equal importance in females, whereas trophic position clearly explained more of the variance than benthic carbon percentage in males. Additionally, strong sex effects (mean difference between females and males equals 45 mg/kg dry wt or 29.4%) were observed in both ecotypes, with female fish having lower THg concentrations than males. These results indicate that trophic ecology and sex are both important determinants of Hg contamination even within a single species and lake and likely play a role in governing Hg concentrations in higher trophic levels. Environ Toxicol Chem 2013;32:1623–1630. © 2013 SETAC
Toxicokinetics of polybrominated diphenyl ethers across life stages in the northern leopard frog (Lithobates pipiens)
Authors: Cary Tawnya L. , Karasov William H. 
Published: March 2013

Abstract

Polybrominated diphenyl ethers (PBDEs), a class of flame retardants, are bioaccumulative toxins that can biomagnify in food webs. However, little is known about the toxicokinetics of total and congener-specific BDEs in lower vertebrates. The authors exposed northern leopard frog (Lithobates (Rana) pipiens) tadpoles to diets containing DE-71 (a pentabromodiphenyl ether mixture (0 ng/g as control, 71.4 ng/g, and 634 DE-71 ng/g wet mass)) for 50 d, followed by a period of depuration during which they were fed only undosed (control) food. After 28 d, tadpoles eliminated over 94% of the ΣPBDEs from their tissues (t½ = 5.9 ± 1.9 d) with no significant differences in elimination rates for the predominant congeners. Elimination of BDE-99 was independent of dose, indicating first-order kinetics. It did not fit a biexponential model significantly better than a monoexponential model, indicating single-compartment elimination. To compare developmental life-stage kinetics following larval exposure, the authors collected individuals at the beginning and end of metamorphosis and at 70 d postmetamorphosis. During metamorphosis, total-body residues per individual did not significantly change, implying little to no elimination. After 70 d, juvenile frogs eliminated 89.7% of the ΣPBDEs from their tissues, and BDE-47 was eliminated at a faster rate (t½= 17.3 d) than BDE-99 and BDE-100 (t½ = 63.0 d and 69.3 d, respectively). Because the kinetics of PBDEs in L. pipiens differed among life stages, developmental life stage—especially for species that undergo metamorphosis—should be considered when determining the toxicity of persistent organic pollutants. Environ Toxicol Chem 2013;32:1631–1640. © 2013 SETAC