bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological Stabilization by Supramolecular Perfluorophenyl‐C60 Interactions Leading to Efficient and Thermally Stable Organic Photovoltaics
Authors: Liao Ming‐Hung , Tsai Che‐En , Lai Yu‐Ying , Cao Fong‐Yi , Wu Jhong‐Sian , Wang Chien‐Lung , Hsu Chain‐Shu , Liau Ian , Cheng Yen‐Ju
Published: October 2013

A new PC61BM‐based fullerene, [6,6]‐phenyl‐C61 butyric acid pentafluorophenyl ester (PC61BPF) is designed and synthesized. This new n‐type material can replace PC61BM to form a P3HT:PC61BPF binary blend or serve as an additive to form a P3HT:PC61BM:PC61BPF ternary blend. Supramolecular attraction between the pentafluorophenyl group of PC61BPF and the C60 cores of PC61BPF/PC61BM can effectively suppress the PC61BPF/PC61BM materials from severe aggregation. By doping only 8.3 wt% PC61BPF, device PC61BPF651 exhibits a PCE of 3.88% and decreases slightly to 3.68% after heating for 25 h, preserving 95% of its original value. When PC61BP with non‐fluorinated phenyl group is used to substitute PC61BPF, the stabilizing ability disappears completely. The efficiencies of PC61BP651 and PC61BP321 devices significantly decay to 0.44% and 0.11%, respectively, after 25 h isothermal heating. Most significantly, this strategy is demonstrated to be effective for a blend system incorporating a low band‐gap polymer. By adding only 10 wt% PC61BPF, the PDTBCDTB:PC71BM‐based device exhibits thermally stable morphology and device characteristics. These findings demonstrate that smart utilization of supramolecular interactions is an effective and practical strategy to control morphological evolution.
Highly Luminescent Covalently Linked Silicon Nanocrystal/Polystyrene Hybrid Functional Materials: Synthesis, Properties, and Processability
Authors: Yang Zhenyu , Dasog Mita , Dobbie Alexander R. , Lockwood Ross , Zhi Yanyan , Meldrum Al , Veinot Jonathan G. C.
Published: October 2013

Silicon nanocrystals (SiNCs) have received much attention because of their exquisitely tunable photoluminescent response, biocompatibility, and the promise that they may supplant their CdSe quantum dot counterparts in many practical applications. One attractive strategy that promises to extend and even enhance the utility of SiNCs is their incorporation into NC/polymer hybrids. Unfortunately, methods employed to prepare hybrid materials of this type from traditional compound semiconductor (e.g., CdSe) quantum dots are not directly transferable to SiNCs because of stark differences in surface chemistry. Herein, the preparation of chemically resistant SiNC/polystyrene hybrids exhibiting exquisitely tunable photoluminescence is reported and material processability is demonstrated by preparing micro and nanoscale architectures.
Formation and Control of Ultrasharp Metal/Molecule Interfaces by Controlled Immobilization of Size‐Selected Metal Nanoclusters onto Organic Molecular Films
Authors: Nakaya Masato , Iwasa Takeshi , Tsunoyama Hironori , Eguchi Toyoaki , Nakajima Atsushi
Published: October 2013

The formation of metallic layers on ultrathin molecular films via a well‐controlled interface is essential for constructing organic nanodevices composed of metal/molecule/metal sandwich junctions. The scanning tunneling microscopy and spectroscopy studies demonstrate that an ultrasharp metal/molecule interface is realizable by depositing size‐selected Ag nanoclusters (Agn) from the gas phase on few‐layer films of C60 molecules. It is also demonstrated that Agn nanoclusters can be immobilized on monolayer films of oligothiophene molecules via C60 molecules, although they three‐dimensionally aggregate on bare oligothiophene films. It is also shown that electrons and holes are injected into the topmost layer of C60 films via the Agn/C60 interface. Moreover, the barrier height for carrier injection at the Agn/C60 interface can be modified depending on the size of Agn nanoclusters and the kinetic energy during the deposition. The present results demonstrate that the controlled immobilization of metallic nanoclusters on molecular films can be used as a fabrication technology for metal/molecule/metal junctions.
The Role of Insulating Oxides in Blocking the Charge Carrier Recombination in Dye‐Sensitized Solar Cells
Authors: Chandiran Aravind Kumar , Nazeeruddin Mohammad K. , Grätzel Michael
Published: October 2013

Electron recombination is one of the major loss factors in dye‐sensitized solar cells (DSC), especially, with single electron outer sphere redox shuttle electrolyte. Insulating sub‐nanometer oxide tunneling layers deposited by atomic layer deposition (ALD) are known to block the electron recombination, thereby leading to an increase in the open‐circuit potential and the collection efficiency of the solar cell. A general perception in the DSC community is that any insulating oxide layer can block the recombination. However, in this work, it is unraveled that the insulating property of oxides alone is not sufficient. In addition, the properties such as the conduction band position and the oxidation state of the insulating oxide, the electronic structural modification induced to the underlying TiO2 mesoporous film, modification of surface charges (isoelectric point) and charge of the electrolyte species have to be considered. A complete photovoltaic study is done by depositing different cycles (by ALD) of four different insulating oxides (Ga2O3, ZrO2, Nb2O5, and Ta2O5) and their recombination characteristics, surface electronic properties, transport rate, and injection dynamics are investigated with a standard organic dye and Co2+/Co3+ redox mediator. A comparison is made with the conventional iodide/triiodide electrolyte.
Highly Efficient Inverted Organic Solar Cells Through Material and Interfacial Engineering of Indacenodithieno[3,2‐b]thiophene‐Based Polymers and Devices
Authors: Intemann Jeremy J. , Yao Kai , Li Yong‐Xi , Yip Hin‐Lap , Xu Yun‐Xiang , Liang Po‐Wei , Chueh Chu‐Chen , Ding Fei‐Zhi , Yang Xi , Li Xiaosong , Chen Yiwang , Jen Alex K.‐Y.
Published: October 2013

A synergistic approach combining new material design and interfacial engineering of devices is adopted to produce high efficiency inverted solar cells. Two new polymers, based on an indacenodithieno[3,2‐b]thiophene‐difluorobenzothiadiazole (PIDTT‐DFBT) donor–acceptor (D–A) polymer, are produced by incorporating either an alkyl thiophene (PIDTT‐DFBT‐T) or alkyl thieno[3,2‐b]thiophene (PIDTT‐DFBT‐TT) π‐bridge as spacer. Although the PIDTT‐DFBT‐TT polymer exhibits decreased absorption at longer wavelengths and increased absorption at higher energy wavelengths, it shows higher power conversion efficiencies in devices. In contrast, the thiophene bridged PIDTT‐DFBT‐T shows a similar change in its absorption spectrum, but its low molecular weight leads to reduced hole mobilities and performance in photovoltaic cells. Inverted solar cells based on PIDTT‐DFBT‐TT are explored by modifying the electron‐transporting ZnO layer with a fullerene self‐assembled monolayer and the MoO3 hole‐transporting layer with graphene oxide. This leads to power conversion efficiencies as high as 7.3% in inverted cells. PIDTT‐DFBT‐TT's characteristic strong short wavelength absorption and high efficiency suggests it is a good candidate as a wide band gap material for tandem solar cells.
Room Temperature Fluorescent Conjugated Polymer Gums
Authors: Jin Young‐Jae , Bae Jung‐Eun , Cho Kwang‐Soo , Lee Wang‐Eun , Hwang Dong‐Yeon , Kwak Giseop
Published: October 2013

High molecular weight poly(diphenylacetylene) [PDPA] derivatives are introduced as fluorescent, soft conjugated polymers that exist in the gum state at room temperature. The gum‐like behavior of the polymers is easily modified according to the side alkyl chain length and substitution position. Long alkyl chain‐coupled PDPA derivatives provide soft and sticky gums at room temperature. Manual kneading of gum polymers produce soft films with very smooth surfaces. The gum polymers show an endothermic transition due to the melting of long alkyl chains. The X‐ray diffraction of gum polymers reveals a new signal due to the molten aliphatic chains. The gum polymers show significant viscoelastic relaxation at the melting temperature of the alkyl side chains. The dynamic thermo‐mechanical analysis (DTMA) of gum polymers at room temperature suggest that the meta‐substituted polymer is softer and stickier than para‐polymer. Rheological analysis suggests that the meta‐polymer has less entanglement than para‐polymer. The fluorescence emission of gum polymer is quite intense in the film and solution. The gum polymer film is readily stretched to produce a uniaxually oriented film. Stretching and subsequent relaxation of elastomer‐supported gum polymer film generate buckles perpendicular to the axis of strain. The gum polymer film accommodates the large strain without cracking and delamination.
Facile Fabrication of Ordered Crystalline‐Semiconductor Microstructures on Compliant Substrates
Authors: Cavallo Francesca , Turner Kevin T. , Lagally Max G.
Published: October 2013

Buckling and wrinkling of thin films on a compliant material has proved to be a resource in several applications, such as flexible electronics, thin‐film metrology and fabrication of tunable optical components. A versatile approach for the fabrication of two‐dimensional and linear arrays of buckled structures is demonstrated here using a stiff material, in the form of a nanomembrane, on a compliant substrate. The novelty of the fabrication process is that the substrates are strained by isotropic volume expansion in solvents. This work illustrates in detail the potential of our technology to fabricate ordered arrays of 3D structures on large‐area compliant substrates, with important implications for a large number of fields. Furthermore, this paper discusses the interesting interface chemistry and mechanics leading to controllable and reproducible fabrication of our 3D structures.
25th Anniversary Article: Chemically Modified/Doped Carbon Nanotubes & Graphene for Optimized Nanostructures & Nanodevices
Authors: Maiti Uday Narayan , Lee Won Jun , Lee Ju Min , Oh Youngtak , Kim Ju Young , Kim Ji Eun , Shim Jongwon , Han Tae Hee , Kim Sang Ouk
Published: October 2013

Outstanding pristine properties of carbon nanotubes and graphene have limited the scope for real‐life applications without precise controllability of the material structures and properties. This invited article to celebrate the 25th anniversary of Advanced Materials reviews the current research status in the chemical modification/doping of carbon nanotubes and graphene and their relevant applications with optimized structures and properties. A broad aspect of specific correlations between chemical modification/doping schemes of the graphitic carbons with their novel tunable material properties is summarized. An overview of the practical benefits from chemical modification/doping, including the controllability of electronic energy level, charge carrier density, surface energy and surface reactivity for diverse advanced applications is presented, namely flexible electronics/optoelectronics, energy conversion/storage, nanocomposites, and environmental remediation, with a particular emphasis on their optimized interfacial structures and properties. Future research direction is also proposed to surpass existing technological bottlenecks and realize idealized graphitic carbon applications.
Food SMEs Face Increasing Competition in the EU Market: Marketing Management Capability Is a Tool for Becoming a Price Maker
Authors: Banterle Alessandro , Cavaliere Alessia , Carraresi Laura , Stranieri Stefanella
Published: October 2013

The price‐making ability of food small and medium‐sized enterprises (SME) is important for their market survival. Since pricing is a part of marketing activities, by developing specific marketing capabilities, firms can improve their ability to make pricing decisions. This paper aims at evaluating the relationship between marketing capabilities and a firm's price‐making ability. A survey was conducted based on a sample of 371 food SMEs in the EU. We applied an Ordinal Regression Model to evaluate the determinants of a firm's price‐making ability. The analysis results revealed a certain ability of SMEs to set prices. Market analysis and marketing strategy planning capabilities are positively related to the price‐making ability of a firm, while firm size is not. Supply chain relationships play a crucial role in price‐making due to the strong constraint presented by the presence of vertical competition between food SMEs and supermarkets. (L25, L66, M31)
Identification of novel candidate gene loci and increased sex chromosome aneuploidy among infants with conotruncal heart defects
Authors: Osoegawa Kazutoyo , Iovannisci David M. , Lin Bin , Parodi Christina , Schultz Kathleen , Shaw Gary M. , Lammer Edward J.
Published: October 2013

Congenital heart defects (CHDs) are common malformations, affecting four to eight per 1,000 total births. Conotruncal defects are an important pathogenetic subset of CHDs, comprising nearly 20% of the total. Although both environmental and genetic factors are known to contribute to the occurrence of conotruncal defects, the causes remain unknown for most. To identify novel candidate genes/loci, we used array comparative genomic hybridization to detect chromosomal microdeletions/duplications. From a population base of 974,579 total births born during 1999–2004, we screened 389 California infants born with tetralogy of Fallot or d‐transposition of the great arteries. We found that 1.7% (5/288) of males with a conotruncal defect had sex chromosome aneuploidy, a sevenfold increased frequency (relative risk = 7.0; 95% confidence interval 2.9–16.9). We identified eight chromosomal microdeletions/duplications for conotruncal defects. From these duplications and deletions, we found five high priority candidate genes (GATA4, CRKL, BMPR1A, SNAI2, and ZFHX4). This is the initial report that sex chromosome aneuploidy is associated with conotruncal defects among boys. These chromosomal microduplications/deletions provide evidence that GATA4, SNAI2, and CRKL are highly dosage sensitive genes involved in outflow tract development. Genome wide screening for copy number variation can be productive for identifying novel genes/loci contributing to non‐syndromic common malformations. © 2013 Wiley Periodicals, Inc.
Developmental and genetic perspectives on Pierre Robin sequence
Authors: Tan Tiong Yang , Kilpatrick Nicky , Farlie Peter G.
Published: October 2013

Pierre Robin sequence (PRS) is a craniofacial anomaly comprising mandibular hypoplasia, cleft secondary palate and glossoptosis leading to life‐threatening obstructive apnea and feeding difficulties during the neonatal period. The respiratory issues require careful management and in severe cases may require extended stays in neonatal intensive care units and surgical intervention such as lengthening the lower jaw or tracheotomy to relieve airway obstruction. These feeding and respiratory complications frequently continue well into childhood, affecting not only growth and development but also impacting on long term educational attainment. The diagnosis of PRS depends on readily recognizable clinical features but the phenotypic similarity of many PRS individuals conceals considerable etiological heterogeneity. Defects in the growth of the mandible sit at the core of PRS and the natural history of PRS can be classified into two major streams: primary defects of mandibular outgrowth and elongation and issues that are external to the mandibular skeleton but that secondarily impact on its growth. These altered developmental trajectories appear to be driven by a range of influences including defects in cartilage growth, neuromuscular function and fetal constraint. Various genetic and cytogenetic associations have been made with PRS and the diversity of these associations highlights the fact that there are numerous ways to arrive at this common phenotypic endpoint. © 2013 Wiley Periodicals, Inc.
Sex‐biased weaning and early childhood diet among middle holocene hunter–gatherers in Central California
Authors: Eerkens Jelmer W. , Bartelink Eric J.
Published: October 2013

This article evaluates age of weaning and early childhood diets of eight males and nine females from a Middle Holocene (4300–3000 BP) site in Central California, CA‐CCO‐548. All individuals died as adults. δ15N values from serial sections of dentin collagen in first molars suggest females were fully weaned, on average, by 3.6 years of age, about 0.4 years later than males in the sample, suggesting possible greater parental investment in female offspring. However, throughout childhood females consumed lower trophic‐level foods than males. This could indicate greater investment in males through provisioning of higher quality foods, or alternatively, some degree of independent foraging by males starting as early as 2 to 3 years of age. Even as adults, these same males and females consumed a different range of foods as indicated by their bone collagen δ13C and δ15N values. Overall, the data suggest children were enculturated early into their respective gendered diets, with girls consuming greater amounts of plant foods and boys consuming greater amounts of higher‐trophic level fish and meat protein. Am J Phys Anthropol 152:471–483, 2013. © 2013 Wiley Periodicals, Inc.
Mechanismen der Autokatalyse
Authors: Bissette Andrew J. , Fletcher Stephen P.
Published: October 2013

Selbstreplikation ist ein fundamentales Konzept. Die Vorstellung von einer Entität, die in wiederholender Weise mehr von sich selbst erzeugen kann, hat die Phantasie vieler Denker von Neumann bis Vonnegut angeregt. Über die Wissenschaft und Science‐Fiction hinaus hat das Konzept der Autokatalyse auch in die Ökonomie und Sprachtheorie Eingang gefunden – und es hat Ängste wie etwa vor “gray goo” (graue Schmiere) geschürt. Die Autokatalyse ist von zentraler Bedeutung für die Ausbreitung des Lebens und bildet die Grundlage vieler anderer biologischer Prozesse, einschließlich des modernen Konzepts der Evolution. Organismen können als unvollkommene “Selbstreplikatoren” betrachtet werden, die nah verwandte Spezies erzeugen und auf diese Weise Auslese und Evolution ermöglichen. Folglich führt jegliche Betrachtung der Selbstreplikation zu einer der tiefgreifendsten Fragen überhaupt: Was ist Leben? Selbstreplizierende Minimalsysteme wurden mit dem Ziel untersucht, die zugrundeliegenden Prinzipien lebender Systemen zu begreifen, um damit unsere Konzepte der biologischen Fitness und chemischen Stabilität, der Selbstorganisation und Emergenz weiterzuentwickeln und letztendlich herausfinden zu können, wie aus Chemie Biologie werden konnte.
Mechanisms of Autocatalysis
Authors: Bissette Andrew J. , Fletcher Stephen P.
Published: October 2013

Self‐replication is a fundamental concept. The idea of an entity that can repeatedly create more of itself has captured the imagination of many thinkers from von Neumann to Vonnegut. Beyond the sciences and science fiction, autocatalysis has found currency in economics and language theory, and has raised ethical fears memorably summed up by the “gray goo” trope. Autocatalysis is central to the propagation of life and intrinsic to many other biological processes. This includes the modern conception of evolution, which has radically altered humanity’s image of itself. Organisms can be thought of as imperfect self‐replicators which produce closely‐related species, allowing for selection and evolution. Hence, any consideration of self‐replication raises one of the most profound questions of all: what is life? Minimal self‐replicating systems have been studied with the aim of understanding the principles underlying living systems, allowing us to refine our concepts of biological fitness and chemical stability, self‐organization and emergence, and ultimately to discover how chemistry may become biology.
Bringing the Science of Proteins into the Realm of Organic Chemistry: Total Chemical Synthesis of SEP (Synthetic Erythropoiesis Protein)
Authors: Kent Stephen B. H.
Published: October 2013

Erythropoietin, commonly known as EPO, is a glycoprotein hormone that stimulates the production of red blood cells. Recombinant EPO has been described as “arguably the most successful drug spawned by the revolution in recombinant DNA technology”. Recently, the EPO glycoprotein molecule has re‐emerged as a major target of synthetic organic chemistry. In this article I will give an account of an important body of earlier work on the chemical synthesis of a designed EPO analogue that had full biological activity and improved pharmacokinetic properties. The design and synthesis of this “synthetic erythropoiesis protein” was ahead of its time, but has gained new relevance in recent months. Here I will document the story of one of the major accomplishments of synthetic chemistry in a more complete way than is possible in the primary literature, and put the work in its contemporaneous context.
Nuclear Deterrence in Asia and the Pacific
Authors: Evans Gareth
Published: October 2013

The Asia Pacific region includes six of the world's nine nuclear‐armed states, and in all of them relevant policymakers, still caught in a Cold War mindset, continue to believe in nuclear deterrence as a force for peace and stability, perceiving nuclear disarmament to be not only unachievable, but undesirable. But—whether the context is major powers seeking to neutralise threats from each other (United States, Russia, China and India), non‐nuclear allies seeking nuclear protection from various threat contingencies (Japan, South Korea and Australia) or vulnerable states seeking a ‘strategic equaliser’ (Pakistan and North Korea)—the traditional strategic arguments for nuclear deterrence are much weaker than they may first seem. Whatever may have been the case for the Cold War years, in today's world the risks associated with the acquisition or retention of nuclear weapons far outweigh any conceivable utility they may have. The financial arguments against them—that they are indefensibly costly—are strong. And the humanitarian arguments are overwhelming: nuclear weapons remain the most indiscriminately inhumane ever devised, and they should be outlawed as chemical and biological weapons have been. Making disarmament happen will never be easy, but—with the right political leadership—is not impossible. Focusing, realistically, in the first instance on minimization rather than elimination, practical steps can be taken to dramatically reduce nuclear weapon numbers, deployment and alert status, and doctrinal reliance on them. Doing so would dramatically reduce, both regionally and globally, the now ever‐present risk of nuclear catastrophe.
Synthesis of Imperatorin Analogs and Their Evaluation as Acetylcholinesterase and Butyrylcholinesterase Inhibitors
Authors: Granica Sebastian , Kiss Anna K. , Jarończyk Małgorzata , Maurin Jan K. , Mazurek Aleksander P. , Czarnocki Zbigniew
Published: October 2013

In this study, we synthesized several imperatorin analogs using imperatorin and xanthotoxin as substrates. The anti‐cholinesterase activities of all compounds were evaluated in in vitro experiments according to the modified Ellman's method. For each synthesized compound, IC50 values for both enzymes were established. Galantamine hydrobromide was used as a positive control in the enzymatic experiments. All active compounds showed selectivity toward butyrylcholinesterase (BuChE) rather than acetylcholinesterase. The most active ones were 8‐(3‐methylbutoxy)‐psoralen and 8‐hexoxypsoralen with IC50 values for BuChE of around 16.5 and 16.4 µM, respectively. The results of our study may be considered as the beginning of a search for potential anti‐Alzheimer's disease drugs based on the structure of natural furocoumarins.
Absence of Interleukin‐17 Receptor A Signaling Prevents Autoimmune Inflammation of the Joint and Leads to a Th2‐like Phenotype in Collagen‐Induced Arthritis
Authors: Corneth Odilia B. J. , Mus Adriana M. C. , Asmawidjaja Patrick S. , Klein Wolterink Roel G. J. , van Nimwegen Menno , Brem Maarten D. , Hofman Yara , Hendriks Rudi W. , Lubberts Erik
Published: October 2013

Objective

Interleukin‐17A (IL‐17A) signals through the IL‐17 receptor (IL‐17R) A/C heterodimer. IL‐17RA serves as a common receptor subunit for several IL‐17 cytokine family members. Lack of IL‐17RA signaling may therefore have additional effects beyond those of lack of IL‐17A alone. The present study was undertaken to determine the role of IL‐17RA signaling in autoimmune arthritis.

Methods

Disease incidence and severity were scored in type II collagen–treated wild‐type, IL‐17RA–deficient, and IL‐23p19–deficient mice. T helper cell profiles and humoral immune responses were analyzed at several time points. Pathogenicity of T cells and total splenocytes was determined by in vitro functional assay. IL‐17RA signaling was blocked in vivo in mice with antigen‐induced arthritis (AIA).

Results

Comparable to the findings in IL‐23p19–deficient mice, IL‐17RA–deficient mice were completely protected against the development of collagen‐induced arthritis (CIA). However, IL‐17RA–deficient mice exhibited an increased number of IL‐4–producing CD4+ T cells, distinct from IL‐17A+CD4+ T cells. This was associated with fewer plasma cells, lower production of pathogenic IgG2c antibody, and increased production of IgG1 antibody. Both isolated CD4+ T cells and total splenocytes from IL‐17RA–deficient mice had a reduced ability to induce IL‐6 production by synovial fibroblasts in the setting of CIA, in a functional in vitro assay. Furthermore, blocking of IL‐17RA signaling in AIA reduced synovial inflammation.

Conclusion

These results demonstrate that absence of IL‐17RA leads to a Th2‐like phenotype characterized by IL‐4 production and suggest that IL‐17RA signaling plays a critical role in the regulation of IL‐4 in CIA and the development of autoimmune inflammation of the joint.
Cost and benefit estimation of experts' mediation in an enterprise search
Authors: Wu Mingfang , Turpin Andrew , Thom James A. , Scholer Falk , Wilkinson Ross
Published: October 2013

The success of an enterprise information retrieval system is determined by interactions among three key entities: the search engine employed; the service provider who delivers, modifies, and maintains the engine; and the users of the service within the organization. Evaluations of an enterprise search have predominately focused on the effectiveness and efficiency of the engine, with very little analysis of user involvement in the process, and none on the role of service providers. We propose and evaluate a model of costs and benefits to a service provider when investing in enhancements to the ranking of documents returned by their search engine. We demonstrate the model through a case study to analyze the potential impact of using domain experts to provide enhanced mediated search results. By demonstrating how to quantify the cost and benefit of an improved information retrieval system to the service provider, our case study shows that using the relevance assessments of domain experts to rerank original search results can significantly improve the accuracy of ranked lists. Moreover, the service provider gains substantial return on investment and a higher search success rate by investing in the relevance assessments of domain experts. Our cost and benefit analysis results are contrasted with standard modes of effectiveness analysis, including quantitative (using measures such as precision) and qualitative (through user preference surveys) approaches. Modeling costs and benefits explicitly can provide useful insights that the other approaches do not convey.
Incentive subsidy scheme design with elastic transport demand
Authors: Zou Wenqian , Mizokami Shoshi
Published: October 2013

Huge public transport subsidies caused by deficits have become a heavy financial burden on some local governments due to the decline of bus passenger numbers. It is essential to apply the performance‐based contract to bus services considering maximization of social welfare. This paper constructs an incentive subsidy contract considering the decision‐making powers of the service level and calculating the proper frequency elasticity aiming at two problems of performance‐based contracts. Meanwhile, we consider a role of bus operators ignored by most researchers. Under the scheme, the decision‐making power of the service level is discussed based on five assumptions, and meanwhile, bus operators are motivated to reduce cost and improve service level in the scheme. The case of the bus service of Arao city indicates that the optimal frequency equals to zero when bus operators decide frequency. If bus operators determine efforts, the optimal effort also equals to zero with the goal of maximizing the profit. Also, bus operators can play their roles in lessening cost and improving service level to help bus operators and the local government achieve a win‐win situation, which maximizes the social benefit in this subsidy scheme when all factors are decided by the government. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of a novel fluorescent probe based on 7‐nitrobenzo‐2‐oxa‐1,3‐diazole skeleton for the rapid determination of vitamin B12 in pharmaceuticals
Authors: Shang Zhuo Bin , Wen Ya Juan , Yan Xiao Qing , Sun Huan He , Wang Yu , Jin Wei Jun
Published: October 2013

A new fluorescent probe, 4‐N,N‐di(2‐hydroxyethyl)imino‐7‐nitrobenzo‐2‐oxa‐1,3‐diazole (HINBD) was synthesized in a single step with reasonably good yield. The water‐soluble HINBD emits strongly in the visible region (λex = 479 nm, λem = 545 nm) and is stable over a wide range of pH values. It was found that vitamin B12 (VB12) had the ability to quench the fluorescence of HINBD, and the quenched fluorescence intensity was proportional to the concentration of VB12. A method for VB12 determination based on the quenching fluorescence of HINBD was thus established. Interference effects of various substances, including sugars, vitamins, amino acids, inorganic cations and some organic substances have been studied. Under optimal conditions, the linear range is 0.0–2.4 × 10–5 mol/L. The determination limit is 8.3 × 10–8 mol/L. The method was applied to measure VB12 in pharmaceutical preparations with satisfactory results. Copyright © 2013 John Wiley & Sons, Ltd.
Temperature‐sensitive elastin‐mimetic dendrimers: Effect of peptide length and dendrimer generation to temperature sensitivity
Authors: Kojima Chie , Irie Kotaro , Tada Tomoko , Tanaka Naoki
Published: October 2013

Dendrimers are synthetic macromolecules with unique structure, which are a potential scaffold for peptides. Elastin is one of the main components of extracellular matrix and a temperature‐sensitive biomacromolecule. Previously, Val‐Pro‐Gly‐Val‐Gly peptides have been conjugated to a dendrimer for designing an elastin‐mimetic dendrimer. In this study, various elastin‐mimetic dendrimers using different length peptides and different dendrimer generations were synthesized to control the temperature dependency. The elastin‐mimetic dendrimers formed β‐turn structure by heating, which was similar to the elastin‐like peptides. The elastin‐mimetic dendrimers exhibited an inverse phase transition, largely depending on the peptide length and slightly depending on the dendrimer generation. The elastin‐mimetic dendrimers formed aggregates after the phase transition. The endothermal peak was observed in elastin‐mimetic dendrimers with long peptides, but not with short ones. The peptide length and the dendrimer generation are important factors to tune the temperature dependency on the elastin‐mimetic dendrimer. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 603–612, 2014.
Structural characterization and bioactivity evaluation of an acidic proteoglycan extract from Ganoderma lucidum fruiting bodies for PTP1B inhibition and anti‐diabetes
Authors: Pan Deng , Wang Linqiang , Hu Bingwen , Zhou Ping
Published: October 2013

A water‐soluble PTP1B inhibitor, named FYGL‐a, was fractionated for structure investigation and bioactivity evaluation. FYGL‐a is an ingredient of a reported antihyperglycemia extract from Ganoderma Lucidum fruiting bodies. Composition analysis indicated that FYGL‐a was a 100.2 kDa acidic proteoglycan, consisting of 85 ± 2% heteropolysaccharide chain with rhamnose, galactose, glucose, and glucuronic acid residues in a mole ratio of 1.0:3.7:3.9:2.0, and the 15 ± 2% protein moiety of FYGL‐a was covalently bonded to the polysaccharide chain in O‐linkage type via threonine residues. The complete sequence of FYGL‐a was characterized systematically by periodate oxidation, Smith degradation, methylation analysis, 1H & 13C 1D NMR, and 2D NMR (HSQC, HMBC, NOESY, COSY, & TOCSY). The chemical structure of FYGL‐a was determined as following, which may play special role in the competitive inhibition of PTP1B and antihyperglycemia potency. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 613–623, 2014.

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Quantitative analysis of five tobacco‐specific N‐nitrosamines in urine by liquid chromatography–atmospheric pressure ionization tandem mass spectrometry
Authors: Xia Baoyun , Xia Yang , Wong Joshua , Nicodemus Keegan J. , Xu Meng , Lee John , Guillot Tonya , Li James
Published: October 2013

A liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of five total tobacco‐specific N‐nitrosamines (TSNA), including free and conjugated forms in urine. The limits of detection for 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol, N′‐nitrosonornicotine, 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone, N′‐nitrosoanatabine and N′‐nitrosoanabasine were 0.6, 0.6, 10.0, 0.4 and 0.4 pg/mL, respectively, with a linear calibration range of up to 20,000 pg/mL. Intra‐ and inter‐day precision for TSNA measurements ranged from 0.82 to 3.67% and from 2.04 to 7.73% respectively. For total TSNAs, the β‐glucuronidase amount was optimized for hydrolysis time and yield. Different liquid chromatography columns and mobile phases with different pH conditions were evaluated. The validated method was then applied to 50 smoker and 30 nonsmoker urine samples. Our results suggest that this sensitive and relatively simple analytical method is suitable for application to epidemiological investigations of health risks associated with the exposure to tobacco smoke or secondhand smoke in both smokers and nonsmokers. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Structure‐guided RP‐HPLC chromatography of diastereomeric α‐helical peptide analogs substituted with single amino acid stereoisomers
Authors: Huang YiBing , Pan Ling , Zhao LianJing , Mant Colin T. , Hodges Robert S. , Chen Yuxin
Published: October 2013

An α‐helical model peptide (Ac‐EAEKAAKE‐X‐EKAAKEAEK‐amide) was used as a template to examine the efficacy of conventional reversed‐phase high‐performance liquid chromatography (RP‐HPLC) in separating peptide analogs with single substitutions (at position X) of diasteromeric amino acids Ile, allo‐Ile, d‐Ile and d‐allo‐Ile. We compared differences in peptide retention behavior on a C8 column and a C18 column at different temperatures. We demonstrated how subtle differences in peptide secondary structure affected by the different substitutions of amino acids with identical overall hydrophobicity enabled effective resolution of these peptide analogs. We also demonstrated the ability of RP‐HPLC to separate Ile‐ and allo‐Ile‐substituted analogs of a 26‐residue α‐helical antimicrobial peptide (AMP), with the substitution site towards the C‐terminus of the α‐helix. These peptides show different values of antibacterial activity and hemolytic activity, and different selectivity against bacteria and human cells. Our results underline the ability of RP‐HPLC to resolve even difficult diasteromeric peptide mixtures as well as its value in monitoring very subtle hydrophobicity changes in de novo‐designed AMP. Copyright © 2013 John Wiley & Sons, Ltd.
Simultaneous determination of three major lignans in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study after oral administration of Diphylleia sinensis extract
Authors: Zhao Chengliang , Zhang Nan , He Weiyan , Li Rui , Shi Dan , Pang Li , Dong Ning , Xu Hong , Ji Honglei
Published: October 2013

A sensitive and selective liquid chromatography tandem mass spectrometry was developed and validated for the simultaneous determination of three major lignans (podophyllotoxin, epipodophyllotoxin, and 4′‐demethylpodophyllotoxin) in rat plasma using diphenhydramine as the internal standard. The analytes were detected using a triple quadrupole mass spectrometer that was equipped with an electrospray ionization source in the positive ion and selected reaction monitoring modes. The linearity of the calibration curve was good, with coefficients of determination (r2) >0.9914 for all of the analytes. The developed method was successfully applied for the simultaneous determination of the three lignans in rat plasma following oral administration of Diphylleia sinensis extract to rats. Copyright © 2013 John Wiley & Sons, Ltd.
Designing controllers for physics‐based characters with motion networks
Authors: Backman Robert , Kallmann Marcelo
Published: October 2013

We present a system that allows non‐programmers to create generic controllers for physically simulated characters. The core of our system is based on a directed acyclic graph of trajectory transformations, which can be modified by feedback terms and serve as reference motions tracked by the physically simulated character. We then introduce tools to enable the automatic creation of robust and parameterized controllers suitable for running in real‐time applications, such as in computer games. The entire process is accomplished by means of a graphical user interface, and we demonstrate how our system can be intuitively used to design a SIMBICON‐like walking controller and a parameterized jump controller to be used in real‐time simulations. Copyright © 2013 John Wiley & Sons, Ltd.
A local adaptive Catmull–Rom to reduce numerical dissipation of semi‐Lagrangian advection
Authors: Huang Zhanpeng , Han Liang , Gong Guanghong
Published: October 2013

We propose an adaptive Catmull–Rom interpolation to improve accuracy of semi‐Lagrangian advection for smoke simulation. Original Catmull–Rom improves numerical accuracy but overshoot violates global stability. Monotonic Catmull–Rom is unconditionally stable, whereas it sweeps out detail features due to overly suppression operations. Our method modifies original Catmull–Rom to obtain second‐order accuracy and unconditional stability. It flattens locations where interpolations might break through global bounds but maintains local overshoots to conserve diversity of fluid flow. The scheme is easy to collaborate with existing fluid simulators to improve small features. Copyright © 2013 John Wiley & Sons, Ltd.
Group Contribution Concept for Computer‐Aided Design of Working Fluids for Refrigeration Machines
Authors: Khetib Y. , Larkeche O. , Meniai A.‐H. , Radwan A.
Published: October 2013

The operation and performance of any refrigeration system depends mainly on the choice of the working fluids. Since classical compounds like the chlorofluorocarbons and hydrochlorofluorocarbons are now completely phased out, substitutes are required. In previous works, a method for computer‐aided design and test of alternative compounds were presented. Relevance and importance of the group contribution concept for such methods are investigated, considering two model systems, namely, the ejecto‐compression and absorption refrigeration machines with specific configurations like insertion of a distillation column and elimination of the condenser, respectively. The obtained results allow extending this approach to model other complex refrigeration systems.
Carbon Dioxide Mass Transfer into Solvents in a Zeolite Hybrid Device
Authors: Gómez‐Díaz D. , Navaza J. M.
Published: October 2013

Carbon dioxide (CO2) mass transfer processes are analyzed in hybrid equipment which involves a zeolitic membrane and a physical or chemical solvent. This separation device was chosen because the membrane can be used to produce a stream of higher CO2 concentration to be treated by gas‐liquid absorption. The analysis of the mass transfer behavior of this gas through the solid phase is an important step before more complicated gas streams are applied. The combined use of both techniques can improve the global separation process because they allow performing a previous separation with a positive effect on the cost of the later separation operations. The influence of the liquid phase nature used in one chamber of the membrane contactor upon CO2 global mass transfer is analyzed. Also the effect caused by the absorption regime, liquid and gas flow rates, and the pressure corresponding to the gas chamber on CO2 mass transfer is studied to evaluate the importance of each variable.
CO2 Capture by Liquid Solvents and their Regeneration by Thermal Decomposition of the Solid Carbonated Derivatives
Authors: Barzagli F. , Lai S. , Mani F.
Published: October 2013

The chemical capture of CO2 by either aqueous Na2CO3 and K2CO3 or nonaqueous solutions of the amines 2‐amino‐2‐methyl‐1‐propanol (AMP) or piperazine (PZ) is described. The captured CO2 is stored as solid NaHCO3, KHCO3, and AMP or PZ carbamates. Solid NaHCO3 and KHCO3 are decomposed at 200 °C and 250 °C, respectively, to regenerate the carbonates for their reuse. In the experiments with AMP or PZ, the solid carbamates are decomposed at 80 °C–110 °C to regenerate the free amines. The absence of water in the desorption‐regeneration step is intriguing and could have the potential of reducing one of the major disadvantages of aqueous absorbents, namely the energy cost of the regeneration step and amine degradation, yet preserving the efficiency of the absorption in the liquid phase.
Kinetic Modeling of Methane Hydrate Formation in the Presence of Low‐Dosage Water‐Soluble Ionic Liquids
Authors: Nazari K. , Moradi M. R. , Ahmadi A. N.
Published: October 2013

The kinetic and thermodynamic effects of three typical low‐dosage imidazolium‐based ionic liquids (ILs) on methane hydrate formation and dissociation were investigated, considering the anion nature and subcooling and/or overpressure driving forces. Isochoric hydrate formation and dissociation data were obtained by the modified slow step‐heating method. ILs proved to have a dual effect on both formation and dissociation of methane hydrate including thermodynamic and kinetic inhibition. Kinetic modeling of methane hydrate inhibition by low‐dosage ILs was performed. Kinetic analysis showed that IL inhibitors mainly cause a delay in the nucleation or hydrate growth step. The related inhibition mechanism was resolved regarding the ionic nature and electrostatic interactions of ILs with water molecules. Two binomial exponential kinetic relations were derived and used for simple methane hydrate formation in the presence of ILs as kinetic hydrate inhibitors. The proposed relations can serve for a quick estimation of the nature, extent, strength, and effectiveness of ILs on various gas hydrates.
Uncovering the Missing Link between Molecular Electrochemistry and Electrocatalysis: Mechanism of the Reduction of Benzyl Chloride at Silver Cathodes
Authors: Klymenko Oleksiy V. , Buriez Olivier , Labbé Eric , Zhan Dong‐Ping , Rondinini Sandra , Tian Zhong‐Qun , Svir Irina , Amatore Christian
Published: October 2013

Herein, the traditional views that contrast the important areas of electrocatalysis and molecular electrochemistry are challenged. By extending Laviron′s seminal concept, we show that these two domains only represent idealized limits of a much broader continuum. More importantly, we show that electrochemical systems that apparently behave experimentally as if under diffusion control (i.e. systems that obey the founding molecular electrochemistry paradigm) may be controlled by electrocatalytic steps, that is, in which the activation of electroactive substrates exclusively occurs through adsorbed intermediates. This analysis is supported through quantitative experimental and theoretical investigations on the reduction of benzyl chloride at silver electrodes. At silver cathodes, the reduction wave of benzyl chloride as monitored at the usual scan rates is dramatically shifted to more positive potentials by about 0.5 V versus that at inert (e.g. glassy carbon) electrodes. This approach, which is based on the use of fast‐scan cyclic voltammetry and simulations (KISSA‐1D), combined with our previous results from surface‐enhanced Raman spectroscopy (SERS) and density functional theory (DFT) analysis, allow us to fully unravel the mechanistic origin of this dramatic effect and quantitatively validate this mechanism, which has eluded many research groups until now. In practice, this example provides a missing link between the traditional areas of electrocatalysis and molecular electrochemistry. Furthermore, it bridges the chemical areas of organometallic/inorganic catalysis and electrochemical activation by showing that the inner‐sphere concept, as developed by Taube and Myers for inorganic reactions, applies perfectly to electrochemical reactions of molecular substrates.
A Photoreducible Copper(II)‐Tren Complex of Practical Value: Generation of a Highly Reactive Click Catalyst
Authors: Harmand Lydie , Lambert Romain , Scarpantonio Luca , McClenaghan Nathan D. , Lastécouères Dominique , Vincent Jean‐Marc
Published: October 2013

A detailed study on the photoreduction of the copper(II) precatalyst 1 to generate a highly reactive cuprous species for the copper(I)‐catalyzed alkyne‐azide cycloaddition (CuAAC) click reaction is presented. For the photoactive catalyst described herein, the activation is driven by a photoinduced electron transfer (PET) process harnessing a benzophenone‐like ketoprofenate chromophore as a photosensitizer, which is equally the counterion. The solvent is shown to play a major role in the CuII to CuI reduction process as the final electron source, and the influence of the solvent nature on the photoreduction efficiency has been studied. Particular attention was paid to the use of water as a potential solvent, aqueous media being particularly appealing for CuAAC processes. The ability to solubilize the copper‐tren complexes in water through the formation of inclusion complexes with β‐CDs is demonstrated. Data is also provided on the fate of the copper(I)‐tren catalytic species when reacting with O2, O2 being used to switch off the catalysis. These data show that partial oxidation of the secondary benzylamine groups of the ligand to benzylimines occurs. Preliminary results show that when prolonged irradiation times are employed a CuI to Cu0 over‐reduction process takes place, leading to the formation of copper nanoparticles (NPs). Finally, the main objective of this work being the development of photoactivable catalysts of practical value for the CuAAC, the catalytic, photolatent, and recycling properties of 1 in water and organic solvents are reported.
Facet‐Dependent Catalytic Activity of Cu2O Nanocrystals in the One‐Pot Synthesis of 1,2,3‐Triazoles by Multicomponent Click Reactions
Authors: Chanda Kaushik , Rej Sourav , Huang Michael H.
Published: October 2013

We report the highly facet‐dependent catalytic activity of Cu2O nanocubes, octahedra, and rhombic dodecahedra for the multicomponent direct synthesis of 1,2,3‐triazoles from the reaction of alkynes, organic halides, and NaN3. The catalytic activities of clean surfactant‐removed Cu2O nanocrystals with the same total surface area were compared. Rhombic dodecahedral Cu2O nanocrystals bounded by {110} facets were much more catalytically active than Cu2O octahedra exposing {111} facets, whereas Cu2O nanocubes displayed the slowest catalytic activity. The superior catalytic activity of Cu2O rhombic dodecahedra is attributed to the fully exposed surface Cu atoms on the {110} facet. A large series of 1,4‐disubstituted 1,2,3‐triazoles have been synthesized in excellent yields with high regioselectivity under green conditions by using these rhombic dodecahedral Cu2O catalysts, including the synthesis of rufinamide, an antiepileptic drug, demonstrating the potential of these nanocrystals as promising heterogeneous catalysts for other important coupling reactions.