bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Bioactive Lipids from the Sponge Spirastrella abata.
Authors: Jang Kyoung Hwa , Lee Yoonyeong , Sim Chung J. , Oh Ki‐Bong , Shin Jongheon 
Published: September 2012

AbstractThree sphingosine 4‐sulfates (I) and a lysophosphatidylglycerol (II) are isolated from the Korean sponge Spirastrella abata.
Application of genetic algorithms in design and optimisation of multi‐stream plate–fin heat exchangers
Authors: Joda Fatemeh , Tahouni Nassim , Panjeshahi Mohammad Hassan 
Published: September 2012

AbstractThis paper introduces two new approaches in the thermo‐hydraulic design of multi‐stream heat exchangers (MSHEs). In both approaches, geometrical aspects of the MSHE (e.g. exchanger dimensions, fin type, etc.) are optimised with a genetic algorithm (GA) using the Total Annual Cost (TAC) as an objective function. The first approach is capable of utilising the maximum allowable stream pressure drops and can result in minimal surface area requirements. In the second approach, all of the pressure drop values are considered as design variables and are therefore subject to optimisation. These approaches have been applied to two case studies taken from literature, and the results are compared to those arising from a currently used design method. In the first case study, application of the new approaches resulted in a smaller TAC than the current approach by 5.77% and 31.86%, respectively, and improvement in the second case was estimated to be 5% and 21.46%, correspondingly. The effect of different fins on an MSHE's TAC is discussed through application of GAs to the current approach. It is shown that correct selection of fin types reduces the TAC of the two case studies by 21.75% and 8.7%, respectively. © 2012 Canadian Society for Chemical Engineering
Design of a multivariable internal model controller based on singular value decomposition
Authors: Jin Qi‐bing , Zhao Liang , Hao Feng , Liu Si‐wen 
Published: September 2012

AbstractIn this article, a novel internal model control (IMC) approach based on singular value decomposition (SVD) is proposed for the control of multiple‐input–multiple‐output (MIMO) systems with multiple time delays. This approach achieves decoupling using a compensation term and improves the robustness using SVD in the inverse of the steady‐state gain matrix of process. Meanwhile, a novel filter is designed for decoupling and fast response speed of multivariable systems with multiple delays. The design of the controller can be extended to non‐square systems where there are more inputs than outputs. Examples are included to illustrate the effectiveness of the method. © 2012 Canadian Society for Chemical Engineering
Blending domain estimates from two victimization surveys with possible bias
Authors: Lohr Sharon L. , Brick J. Michael 
Published: September 2012

AbstractDual frame survey methods are popular for blending estimates from two independent surveys that measure the same quantities. The relative weights assigned to observations from the surveys may be used for direct small domain estimates. In this paper, we explore methods for small domain estimation from two surveys when one survey may be biased relative to the other. These methods are explored in the context of a proposed new companion survey for the US National Crime Victimization Survey. The Canadian Journal of Statistics 40: 679–696; 2012 © 2012 Statistical Society of Canada
Electrocatalytic Reduction of Acetone in a Proton‐Exchange‐Membrane Reactor: A Model Reaction for the Electrocatalytic Reduction of Biomass
Authors: Green Sara K. , Tompsett Geoffrey A. , Kim Hyung Ju , Kim Won Bae , Huber George W. 
Published: September 2012

AbstractAcetone was electrocatalytically reduced to isopropanol in a proton‐exchange‐membrane (PEM) reactor on an unsupported platinum cathode. Protons needed for the reduction were produced on the unsupported PtRu anode from either hydrogen gas or electrolysis of water. The current efficiency (the ratio of current contributing to the desired chemical reaction to the overall current) and reaction rate for acetone conversion increased with increasing temperature or applied voltage for the electrocatalytic acetone/water system. The reaction rate and current efficiency went through a maximum with respect to acetone concentration. The reaction rate for acetone conversion increased with increasing temperature for the electrocatalytic acetone/hydrogen system. Increasing the applied voltage for the electrocatalytic acetone/hydrogen system decreased the current efficiency due to production of hydrogen gas. Results from this study demonstrate the commercial feasibility of using PEM reactors to electrocatalytically reduce biomass‐derived oxygenates into renewable fuels and chemicals.
Adaptive modulation with constrained variable power for space–time coded MIMO systems
Authors: Yu Xiangbin , Liu Xiaoshuai , Zhu Qiuming , Xu Dazhuan 
Published: September 2012

SUMMARYPractically, the maximum transmission power of transmission systems is limited. This power constraint causes the variable power control derived from no maximum power limitation suffering from performance degradation. In this paper, a constrained variable‐power adaptive M‐ary quadrature amplitude modulation scheme for MIMO systems with space–time coding is developed. Convex optimization is used to derive the switching thresholds of the instantaneous signal‐to‐noise ratio for power control (PC) and adaptive modulation under the constraints of maximum power, average power, and target BER. In the derivation of the relation between modulation and power, the exact BER expression of binary phase shift keying modulation and a tight bound for higher order quadrature amplitude modulation are used to make the PC scheme fulfill the target BER even at low signal‐to‐noise ratio where the previous PC schemes fail to meet the target BER. Numerical results show that the derived control scheme under the power constraints can obtain the spectrum efficiency and BER performance close to the previous control scheme without power limitation. Moreover, it can satisfy the requirements of power limitation and target BER and can effectively avoid the excessive power consumption of previous PC scheme in poor channel condition. Copyright © 2012 John Wiley & Sons, Ltd.
Coupling model uncertainty for coupled rainfall/runoff and surface water quality models in river problems
Authors: Parker Geoffrey T. , Droste Ronald L. , Rennie Colin D. 
Published: September 2012

ABSTRACTCoupled hydrology and water quality models are an important tool today, used in the understanding and management of surface water and watershed areas. Such problems are generally subject to substantial uncertainty in parameters, process understanding, and data. Component models, drawing on different data, concepts, and structures, are affected differently by each of these uncertain elements. This paper proposes a framework wherein the response of component models to their respective uncertain elements can be quantified and assessed, using a hydrological model and water quality model as two exemplars. The resulting assessments can be used to identify model coupling strategies that permit more appropriate use and calibration of individual models, and a better overall coupled model response. One key finding was that an approximate balance of water quality and hydrological model responses can be obtained using both the QUAL2E and Mike11 water quality models. The balance point, however, does not support a particularly narrow surface response (or stringent calibration criteria) with respect to the water quality calibration data, at least in the case examined here. Additionally, it is clear from the results presented that the structural source of uncertainty is at least as significant as parameter‐based uncertainties in areal models. Copyright © 2012 John Wiley & Sons, Ltd.
Redox‐Active Guanidine Ligands with Pyridine and p‐Benzoquinone Backbones
Authors: Stang Simone , Lebkücher Anna , Walter Petra , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: September 2012

AbstractHerein we report on the synthesis and some aspects of the chemistry of the new redox‐active ligands 2,3,5,6‐tetrakis(tetramethylguanidino)pyridine, 2,3,5,6‐tetrakis(tetramethylguanidino)‐p‐benzoquinone and 2,3,5,6‐tetrakis(N,N′‐dimethyl‐N,N′‐ethyleneguanidino)‐p‐benzoquinone. All three ligands are strong electron donors. In addition, the p‐benzoquinone systems feature low LUMO energies and small HOMO–LUMO gaps. A comparison of the ligands was made with regard to their optical properties, Brønsted basicity and electron‐donor properties; results of quantum chemical calculations were included in this comparison. Subsequently, dinuclear copper complexes were prepared. Preliminary experiments on their redox chemistry followed.
Functional Hybrid Materials Based on Layered Simple Hydroxide Hosts and Dicarboxylate Schiff Base Metal Complex Guests
Authors: Eyele‐Mezui Séraphin , Delahaye Emilie , Rogez Guillaume , Rabu Pierre 
Published: September 2012

AbstractThe insertion of carboxysalen‐type complexes into magnetic layered transition‐metal simple hydroxides has provided new hybrid compounds. Three kinds of carboxysalen ligands have been used: an ethylenediamine bridge (SED‐H2), a chiral cyclohexanediamine bridge [(S,S)‐SCD‐H2 and (R,R)‐SCD‐H2], and an aromatic o‐phenylenediamine bridge (SBD‐H2). The ccorresponding CuII, NiII, CoII, ZnII, MnIII, and AlIII complexes were synthesized and inserted into layered cobalt and copper hydroxides. The structural and spectroscopic investigations confirmed the successful insertion‐grafting of the complexes leading to new layered hybrid materials in which the inserted complexes act as pillars between the inorganic layers. The use of carboxylate anchoring functions enabled some of the difficulties encountered during the previously reported insertion of sulfonatosalen complex analogues to be overcome, namely hydrolysis and decomplexation during the insertion reaction. Hence, in this work it was possible to insert a wide variety of complexes into layered simple hydroxides, including MIII complexes, for the first time. The insertion of chiral carboxysalen complexes led to the formation of chiral magnets in which chirality transfer to the inorganic layers was evidenced and seems to be favored by the carboxylate anchoring groups. Finally, magnetic characterization showed that the copper hydroxide hybrids exhibit overall antiferrimagnetic behavior, whereas the cobalt hydroxide hybrids present ferromagnetic ordering, with ordering temperatures ranging from 6.5 to 12.8 K. In this case the nature of the cation inserted between the layers influences the magnetic behavior of the hybrid, contrary to what was observed in the case of the sulfonate analogues.
CuI/SnCl2 Co‐Catalyzed Four‐Component Reaction of Ketones, Amines, Alkynes, and Carbon Dioxide
Authors: Zhao Jinwu , Huang Huawen , Qi Chaorong , Jiang Huanfeng 
Published: September 2012

AbstractThe four‐component CuI and SnCl2 co‐catalyzed assembly of ketones, amines, alkynes, and carbon dioxide could be performed in DMSO at 70 °C under CO2 pressure to synthesize 5‐alkynlene oxazolidinones. It was found that steric hindrance had an extreme effect on the four‐component coupling. Aliphatic ketones, basic primary amines, and aryl alkynes were good substrates.
Potassium 4‐Iodylbenzenesulfonate: Preparation, Structure, and Application as a Reagent for Oxidative Iodination of Arenes
Authors: Yusubov Mekhman S. , Yusubova Roza Y. , Nemykin Victor N. , Maskaev Andrey V. , Geraskina Margarita R. , Kirschning Andreas , Zhdankin Viktor V. 
Published: September 2012

AbstractA new hypervalent iodine(V) compound, potassium 4‐iodylbenzenesulfonate, was prepared by the oxidation of 4‐iodobenzensulfonic acid with Oxone in water. This potassium salt can be further converted into 4‐iodylbenzenesulfonic acid by treatment with the acidic form of Amberlyst 15 in water. A single‐crystal X‐ray structure of potassium 4‐iodylbenzenesulfonate revealed the presence of polymeric chains in the solid state due to a combination of numerous intra‐ and intermolecular interactions. Potassium 4‐iodylbenzenesulfonate will likely find many practical applications as a thermally stable and water‐soluble hypervalent iodine‐based oxidant, particularly useful as a reagent for oxidative iodination of aromatic substrates. This reagent can be effectively recovered from the reaction mixture (92 % recovery) by treatment of the aqueous layer with Oxone at 60 °C for 2 h, followed by filtration of the precipitate.
Correlation in spectral accelerations for earthquakes in Europe
Authors: Cimellaro Gian Paolo 
Published: September 2012

ABSTRACTThe shape of a uniform hazard spectrum has been criticized to be unrealistic for a site where the spectral ordinates of the uniform hazard spectrum at different periods are governed by different scenario events and conservative for long‐return‐period earthquake shaking. The conditional mean spectrum considering epsilon (CMS‐ε) takes into account the correlation of spectral demands (represented by values of ε) at different periods, to address these issues. This paper proposes new prediction models for the correlation coefficient of ε(T1) and ε(T2), a key component for developing a CMS, using Pan‐European earthquake records from a European ground motion database. Epsilon (ε) for each record is computed using the 2005 Ambraseys ground‐motion prediction equation. The model can be used to develop CMS for European sites, and it can be incorporated in the European seismic standards. Copyright © 2012 John Wiley & Sons, Ltd.
Parallel fully implicit two‐grid methods for distributed control of unsteady incompressible flows
Authors: Yang Haijian , Cai Xiao‐Chuan 
Published: September 2012

SUMMARYIn this paper, we investigate some fully coupled parallel two‐grid Lagrange–Newton–Krylov–Schwarz algorithms for the suboptimal distributed control of unsteady incompressible flows governed by the Navier–Stokes equations. The algorithms include two major parts: a two‐grid Newton method for the nonlinear part of the problem and a two‐level Schwarz preconditioner for the linear part of the problem. Most of the existing approaches for distributed control problems are based on the so‐called reduced space method, which is easier to implement, but may have convergence issues in some situations. In the full space approach, we couple the state variables, the control variables, and the adjoint variables in a single large system of nonlinear equations. The coupled system is considerably more ill‐conditioned than its sub‐systems; however, with the powerful two‐grid approach, we are able to solve these difficult systems efficiently on large scale parallel computers. We show numerically that such an approach is scalable in the sense that the number of Newton iterations and the number of linear iterations are both nearly independent of the grid size, the number of processors, and the Reynolds numbers. We present numerical experiments for some suboptimal control problems obtained on supercomputers with more than two thousand processors. Copyright © 2012 John Wiley & Sons, Ltd.
Depressive symptoms and frailty
Authors: St. John Philip D. , Tyas Suzanne L. , Montgomery Patrick R. 
Published: September 2012

BackgroundFrailty and depressive symptoms are common issues facing older adults and may be associated.ObjectivesTo determine if: (i) depressive symptoms are associated with frailty; (ii) there is a gradient in this effect across the range of depressive symptoms; and (iii) the association between depressive symptoms and frailty is specific to particular types of depressive symptoms (positive affect, negative affect, somatic complaints, and interpersonal relations).MethodSecondary analysis of an existing population‐based study was conducted.PopulationIn 1991, 1751 community‐living adults aged 65+ years were interviewed.MeasuresDepressive symptoms were measured using the Center for Epidemiologic Studies—Depression (CES‐D) scale. Frailty was graded from 0 (no frailty) to 3 (moderate/severe frailty). Age, gender, education, marital status, self‐rated health, and the number of comorbid conditions were self‐reported.AnalysesLogistic regression models were constructed with the outcome of no frailty/urinary incontinence only versus frailty.ResultsDepressive symptoms were strongly associated with frailty, and there was a gradient effect across the entire range of the CES‐D scale. The odds ratio and 95% confidence interval was 1.08 (1.06, 1.09) per point of the CES‐D in unadjusted models. After potential confounding factors were adjusted, the adjusted odds ratio (95% confidence interval) was 1.03 (1.01, 1.05). Positive affect, negative affect, and somatic complaints were all associated with frailty, whereas interpersonal relations were not associated with frailty.ConclusionsDepressive symptoms are associated with frailty. Clinicians should consider assessing frail older adults for the presence of depression. Copyright © 2012 John Wiley & Sons, Ltd.
Multisystem physiological dysfunction is associated with depressive symptoms in a population‐based sample of older adults
Authors: Kobrosly Roni W. , Seplaki Christopher L. , Cory‐Slechta Deborah A. , Moynihan Jan , van Wijngaarden Edwin 
Published: September 2012

ObjectiveTo evaluate the association between multisystem physiological dysfunction and depressive symptom severity in the US older adults.MethodsWe examined 2405 adults of age 60 years and older by using the data from the 2005–2008 National Health and Nutrition Examination Survey. We constructed a summary score of “physiological dysfunction,” encompassing cardiovascular function, glucose regulation, liver function, and renal function. Overall depressive symptoms were obtained from the 9‐item Patient Health Questionnaire depression scale, and factor analysis was used to derive affective and somatic symptom scores. We employed multiple linear regression models to estimate associations between physiological dysfunction scores and affective, somatic, and overall depressive symptoms, while adjusting for demographic, socioeconomic factors, and other potentially confounding factors.ResultsGreater multisystem physiological dysfunction scores were associated with an increased severity of overall, affective, and somatic depressive symptoms. These associations persisted after adjusting for all covariates: beta = 0.23 (95% confidence interval (CI) = 0.13, 0.32); beta = 0.08 (95% CI = 0.04, 0.11); beta = 0.12 (95% CI = 0.06, 0.18), respectively.ConclusionsOur results suggest that the multisystem physiological dysfunction is associated with late‐life depressive symptoms. Additional longitudinal studies of links between allostatic load, psychosocial stress events throughout the life course, and late‐life depressive symptoms may shed further light on this association. Copyright © 2012 John Wiley & Sons, Ltd.
Roles of hepatocyte and myeloid CXC chemokine receptor-2 in liver recovery and regeneration after ischemia/reperfusion in mice
Authors: Van Sweringen Heather L. , Sakai Nozomu , Quillin Ralph C. , Bailey Jeff , Schuster Rebecca , Blanchard John , Goetzman Holly , Caldwell Charles C. , Edwards Michael J. , Lentsch Alex B. 
Published: September 2012

Abstract
Previous studies have demonstrated the significance of signaling through the CXC chemokine receptor-2 (CXCR2) receptor in the process of recovery and regeneration of functional liver mass after hepatic ischemia/reperfusion (I/R). CXCR2 is constitutively expressed on both neutrophils and hepatocytes; however, the cell-specific roles of this receptor are unknown. In the present study, chimeric mice were created through bone marrow transplantation (BMT) using wild-type and CXCR2-knockout mice, yielding selective expression of CXCR2 on hepatocytes (Hep) and/or myeloid cells (My) in the following combinations: Hep+/My+; Hep−/My+; Hep+/My−; and Hep−/My−. These tools allowed us to assess the contributions of myeloid and hepatocyte CXCR2 in the recovery of the liver after I/R injury. Flow cytometry confirmed the adoption of the donor phenotype in neutrophils. Interestingly, Kupffer cells from all chimeras lacked CXCR2 expression. Recovery/regeneration of hepatic parenchyma was assessed by histologic assessment and measurement of hepatocyte proliferation. CXCR2Hep+/My+ mice showed the least amount of liver recovery and hepatocyte proliferation, whereas CXCR2Hep−/My− mice had the greatest liver recovery and hepatocyte proliferation. CXCR2Hep+/My− mice had enhanced liver recovery, with hepatocyte proliferation similar to CXCR2Hep−/My− mice. Myeloid expression of CXCR2 directly regulated CXC chemokine expression levels after hepatic I/R, such that mice lacking myeloid CXCR2 had markedly increased chemokine expression, compared with mice expressing CXCR2 on myeloid cells. Conclusion: The data suggest that CXCR2 on myeloid cells is the predominant regulator of liver recovery and regeneration after I/R injury, whereas hepatocyte CXCR2 plays a minor, secondary role. These findings suggest that myeloid cell-directed therapy may significantly affect liver regeneration after liver resection or transplantation. (Hepatology 2013)
A novel murine model to deplete hepatic stellate cells uncovers their role in amplifying liver damage in mice
Authors: Puche Juan E. , Lee Youngmin A. , Jiao Jingjing , Aloman Costica , Fiel Maria I. , Muñoz Ursula , Kraus Thomas , Lee Tingfang , Yee Hal F. , Friedman Scott L. 
Published: September 2012

Abstract
We have developed a novel model for depleting mouse hepatic stellate cells (HSCs) that has allowed us to clarify their contributions to hepatic injury and fibrosis. Transgenic (Tg) mice expressing the herpes simplex virus thymidine kinase gene (HSV-Tk) driven by the mouse GFAP promoter were used to render proliferating HSCs susceptible to killing in response to ganciclovir (GCV). Effects of GCV were explored in primary HSCs and in vivo. Panlobular damage was provoked to maximize HSC depletion by combining CCl4 (centrilobular injury) with allyl alcohol (AA) (periportal injury), as well as in a bile duct ligation (BDL) model. Cell depletion in situ was quantified using dual immunofluorescence (IF) for desmin and GFAP. In primary HSCs isolated from both untreated wild-type (WT) and Tg mice, GCV induced cell death in ˜50% of HSCs from Tg, but not WT, mice. In TG mice treated with CCl4+AA+GCV, there was a significant decrease in GFAP and desmin-positive cells, compared to WT mice (˜65% reduction; P < 0.01), which was accompanied by a decrease in the expression of HSC-activation markers (alpha smooth muscle actin, beta platelet-derived growth factor receptor, and collagen I). Similar results were observed after BDL. Associated with HSC depletion in both fibrosis models, there was marked attenuation of fibrosis and liver injury, as indicated by Sirius Red/Fast Green, hematoxylin and eosin quantification, and serum alanine/aspartate aminotransferase. Hepatic expression of interleukin-10 and interferon-gamma was increased after HSC depletion. No toxicity of GCV in either WT or Tg mice accounted for the differences in injury. Conclusion: Activated HSCs significantly amplify the response to liver injury, further expanding this cell type's repertoire in orchestrating hepatic injury and repair. (Hepatology 2013)