bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and performance of an efficient rectenna incorporating a fractal structure
Authors: Choi Dong‐You , Shrestha Sika , Park Jung‐Jin , Noh Sun‐Kuk 
Published: July 2013

SUMMARYWe present an efficient rectenna capable of harvesting ambient radio frequency energy to obtain utilizable direct current power at a frequency of 2.45 GHz. The rectifying antenna incorporates a fractal structure at its antenna section. The unique space‐filling property of fractals is implemented to develop an antenna with a significant size reduction. A Sierpinski carpet, which is a simple and effective fractal design, is edge‐fed and iterated up to the 3rd order. The received signal from the 2nd‐order fractal iterated patch antenna is rectified using a rectifier circuit that uses an HSMS 8202 (Avago Technologies, California, USA) diode. The realized rectenna has the capacity to exhibit a maximum efficiency of 57% at an input power level of 20 dBm. Simulations for the fractal iterated patch antennas and rectifier circuit are performed in Ansoft HFSS, Ver. 10 (Ansys, Canonsburg, USA) and ADS (Agilent Technologies, Mississauga, Canada), respectively. The simulated antenna and rectenna are experimentally tested to verify the simulation results. The simulation and experimental results for the antenna and rectenna design are found to be in good agreement with each other. Copyright © 2013 John Wiley & Sons, Ltd.
A Silicon‐Heteroaromatic System as Photosensitizer for Light‐Driven Hydrogen Production by Hydrogenase Mimics
Authors: Goy Roman , Apfel Ulf‐Peter , Elleouet Catherine , Escudero Daniel , Elstner Martin , Görls Helmar , Talarmin Jean , Schollhammer Philippe , González Leticia , Weigand Wolfgang 
Published: July 2013

AbstractThe utilization of light and inexpensive catalysts to afford hydrogen represents a huge challenge. Following our interest in silicon‐containing [FeFe]‐hydrogenase ([FeFe]‐H2ase) mimics, we report a new model approach for a photocatalytic [FeFe]‐H2ase mimic 1, which contains a 1‐silafluorene unit as a photosensitizer. Thereby, the photoactive ligand is linked to the [2Fe2S] cluster through S–CH2–Si bridges. Photochemical H2 evolution experiments were performed and revealed a turnover number (TON) of 29. This is the highest reported photocatalytic efficiency for an [FeFe]‐H2ase model complex in which the photosensitizer is covalently linked to the catalytic center.
Intramolecular Hydrogen Bonding in CuII Complexes with 2,6‐Pyridinedicarboxamide Ligands: Synthesis, Structural Characterization, and Physical Properties
Authors: Wang Denan , Lindeman Sergey V. , Fiedler Adam T. 
Published: July 2013

AbstractThe significance of second‐sphere interactions in synthetic catalysts and metalloenzyme active sites has encouraged the development of ligand frameworks capable of supporting intramolecular hydrogen‐bonding networks. With this approach in mind, we prepared a series of 2,6‐pyridinedicarboxamide ligands (H2LX) that feature outer‐sphere heterocyclic groups (pyridine, pyrimidine, or quinoline rings). Reaction with CuCl2 yields complexes with the general formula [CuCl2(LX{H}2)] (1X), in which the pincer ligands coordinate to the CuII center in a tridentate fashion through the central pyridine and two amidato nitrogen atoms. The LX{H}2 ligands have no net charge, however, as the pendant heterocycles are both protonated. X‐ray crystallographic studies revealed that the two outer‐sphere N–H groups form intramolecular hydrogen bonds with the chlorido ligands. Modification of the syntheses provided CuII complexes (i.e., 2X, 3X) that contain an aqua ligand hydrogen bonded to the outer‐sphere group(s). Whereas complexes with the LX{H}2 ligands are mononuclear, deprotonation gives rise to dimeric complexes (i.e., 4X, 5X) in which one of the pendant heterocycles coordinates to a second CuII center. The complexes were also examined with electronic absorption spectroscopy, cyclic voltammetry, and density functional theory. Our results indicate that the LX{H}2 ligands, despite their neutrality, maintain the strong σ‐donating ability of anionic pyridine‐amidato ligands.
Polar Groups and Arylsulfonamides: A Good Combination with which to Obtain Supramolecular Columnar Liquid Crystals
Authors: Zennaro Angela , Hincapié Cesar Augusto , Martos Alba , Sebastián Rosa M. , Barberá Joaquín , Serrano José Luis , Sierra Teresa 
Published: July 2013

AbstractMesomorphic arylsulfonamide derivatives containing four long alkyl chains and polar groups (fluoro, cyano or amino) have been synthesized and characterized by polarized optical microscopy, differential scanning calorimetry, and X‐ray diffraction on the mesophase. Studies of the supramolecular organization of these molecules have allowed a better understanding of the noncovalent driving forces (dipole···dipole and hydrogen‐bonding interactions) responsible for the self‐assembly, which is mainly due to the presence of the polar groups.
Rapid and Controllable Hydrogen/Deuterium Exchange on Aromatic Rings of α‐Amino Acids and Peptides
Authors: Murai Yuta , Wang Lei , Masuda Katsuyoshi , Sakihama Yasuko , Hashidoko Yasuyuki , Hatanaka Yasumaru , Hashimoto Makoto 
Published: July 2013

AbstractNovel hydrogen/deuterium exchange for aromatic α‐amino acids and their corresponding peptides were performed through the use of deuterated trifluoromethanesulfonic acid (TfOD). Detailed analysis of the exchange revealed that equal hydrogen/deuterium exchange was observed for phenylalanine, and specific exchange at the ortho‐positions of phenol for tyrosine was also detected. The stereochemistry of the aromatic α‐amino acids was retained under the exchange conditions. The hydrogen/deuterium exchange properties for these aromatic α‐amino acids are identical for peptides that contain several aromatic α‐amino acids. The exchange proceeded significantly faster than previous methods. Detailed analysis of the exchange revealed that the method could be controlled by temperature, time, and the amount of reagent.
C‐5′‐Substituted Cinchona Alkaloid Derivatives Catalyse the First Highly Enantioselective Dynamic Kinetic Resolutions of Azlactones by Thiolysis
Authors: Palacio Carole , Connon Stephen J. 
Published: July 2013

AbstractThe highly enantioselective dynamic kinetic resolution (DKR) of azlactones by thiolysis has been achieved for the first time. Although both the parent alkaloid quinine and known C‐5′‐urea derivatives fail to promote the reaction effectively, a new class of C‐5′‐hydroxylated catalysts proved capable of catalysing the DKR of a range of azlactones derived from both unbranched‐ and, previously challenging, branched‐chain amino acids in 84–92 % ee, including an example of the synthesis of an enantioenriched N‐protected thioester derived from an extraterrestrial amino acid isolated from the Murchison meteorite.
Ligand‐Free Suzuki Cross‐Coupling Reactions: Application to β‐Halo‐α,β‐Unsaturated Aldehydes
Authors: Gogoi Pranjal , Bezboruah Pranjal , Boruah Romesh C. 
Published: July 2013

AbstractA facile, efficient, ligand‐free Suzuki–Miyaura reaction of β‐halo α,β‐unsaturated aldehydes with boronic acids in aqueous media at room temperature is described. Under the optimized conditions, both steroidal and nonsteroidal β‐halo α,β‐unsaturated aldehydes reacted rapidly with the boronic acids to provide a series of aryl‐substituted derivatives in excellent yields. Moreover, the protocol was extended to the direct one‐pot synthesis of polycyclic aromatic hydrocarbons through a Suzuki–Miyaura cross‐coupling/aldol condensation cascade reaction under microwave irradiation.
Rhodium‐Catalyzed Reaction of Diazonaphthoquinones and Enol Ethers: Synthesis of Dihydronaphthofuran Derivatives and α‐Naphthyl Esters
Authors: Kitamura Mitsuru , Araki Keiichiro , Matsuzaki Hiroki , Okauchi Tatsuo 
Published: July 2013

AbstractDihydronaphthofurans were synthesized by the Rh2(OAc)4‐catalyzed cycloaddition reaction of 1,2‐diazonaphthoquinones with enol ethers. The dihydronaphthofurans formed from diazonaphthoquinones and ketene silyl acetals were transformed into α‐naphthyl esters by treatment with tetrabutylammonium fluoride.
Dynamic buckling and seismic fragility of anchored steel tanks by the added mass method
Authors: Buratti N. , Tavano M. 
Published: July 2013

SUMMARYBuckling plays a fundamental role in the design of steel tanks because of the small thicknesses of the walls of this class of structures. The first part of the paper presents a review of this phenomenon for liquid‐containing circular cylindrical steel tanks that are fully anchored at the base, considering the different buckling modes and especially the secondary buckling occurring in the top part of the tank.A case study based on a cylindrical tank is then introduced in order to investigate various aspects of dynamic buckling. The finite element model of the case study tank is set‐up using the added mass method for fluid modelling. The influence of pre‐stress states caused by hydrostatic pressure and self‐weight on the natural periods of the structure is first studied and it is found that this influence is very small as far as the global behaviour of the tanks is considered, while it is important for local, shell‐type, vibration modes.In the following, the efficiency and sufficiency of different ground motion intensity measures is analysed by means of cloud analysis with a set of 40 recorded accelerograms. In particular, the peak ground displacement has been found being the most efficient and sufficient intensity measure so far as the maximum relative displacement of the tank walls is concerned.Finally, incremental nonlinear time‐history analyses are performed considering the case study structure under recorded earthquake ground motions in order to identify the critical buckling loads and to derive fragility curves for the buckling limit state. Copyright © 2013 John Wiley & Sons, Ltd.
AN INSTRUMENT FOR MEASURING THE SOCIAL WILLINGNESS TO PAY FOR HEALTH STATE IMPROVEMENT
Authors: Richardson Jeff , Iezzi Angelo , Sinha Kompal , Khan Munir A. , Mckie John 
Published: July 2013

ABSTRACTThis paper describes an instrument for measuring the social value of changes in health status, the Relative Social Willingness to Pay. It is a unique combination of measurement attributes designed to minimise cognitive complexity and provide an additional option for measuring ‘social value’. Similar to the person trade‐off (PTO), it adopts a social perspective and asks respondents to evaluate programmes on behalf of society. Unlike the PTO, trade‐offs between the options use dollars, not numbers of patients. Respondents are not, however, asked for their personal willingness to pay. Rather, the opportunity cost of funds spent on one service is as an offsetting reduction in funds for a second service. The amount spent on each service therefore indicates relative, not absolute, value. However, the two services combine to produce one Quality adjusted life year which allows the calculation of a Quality adjusted life year‐like unit of social value on a 0–1 scale. A three‐stage survey was used to test the instrument's reliability, validity and sensitivity to the framing of the main question. Results indicate that the Relative Social Willingness to Pay produces values similar to but less than the PTO and time trade‐off techniques. Copyright © 2013 John Wiley & Sons, Ltd.
Question the Unquestionable Beauty of A Collective Proceeding for All Sovereign Debt Claims
Authors: Li Yanying 
Published: July 2013

AbstractThe new challenges presented by the current Eurozone crisis and the NML Capital v. Argentina case are likely to shift the international community's attention from holdout behavior in foreign bonds restructuring to inter‐creditor issues. In the past years, many academics, and nongovernmental organizations concerned with debt relief, have put forward proposals to create a bankruptcy regime for states. But none of these proposals has seriously examined what rules should apply to treatment among creditors. Moreover, all insist that there must be a collective proceeding for all sovereign debt claims, without explaining why. This approach is simply taken for granted, as it is one of the fundamental principles of bankruptcy law. The article questions this orthodoxy through examining the nature of sovereign debt crisis, the feature of the limited pool of sovereign assets, and the nonliquidable fact of the sovereign debtor. It also argues that the common pool problem does not exist in the sovereign debt context.
Ionic Supramolecular Assemblies
Authors: Lin Xinrong , Grinstaff Mark W. 
Published: July 2013

AbstractSupramolecular structures assembled via noncovalent interactions have found diverse applications in mechanical, biological, electronic, and manufacturing‐related fields. Ionic interactions represent key noncovalent interactions, which can be used, for example, to create highly ordered, responsive, conductive, reversible, and/or viscoelastic supramolecular assemblies. The recent advances in the field of ionic supramolecular assemblies, including those prepared from polymers, small molecules, or a combination of the two are reviewed. The versatility and simplicity of constructing ionic supramolecular assemblies are illustrated through several examples. Finally, the outstanding issues and potential opportunities are discussed to stimulate critical discussions and encourage further discovery.
Asynchronous formation of Hesperian and Amazonian‐aged deltas on Mars and implications for climate
Authors: Hauber E. , Platz T. , Reiss D. , Le Deit L. , Kleinhans M. G. , Marra W. A. , de Haas T. , Carbonneau P. 
Published: July 2013

AbstractMost fluvial and lacustrine landforms on Mars are thought to be old and have formed more than ~3.8 Gyr ago, in the Noachian period. After a major climatic transition, surface liquid water became less abundant and finally disappeared almost completely. Recent work has shown that observational evidence for Hesperian and Amazonian aqueous processes is more common than previously recognized, but their nature is poorly understood. Moreover, it is not clear how the paleoclimate of Mars can be constrained by this activity. Here we report our investigation of a population of deltas around the ancient impact basin Chryse Planitia. To test whether the results are globally applicable, we also studied selected deltas with similar morphologies in the eastern hemisphere and found that the results are consistent. We compared the morphology of deltas, feeder channels, and receiving lakes, dated deltas by crater counting and searched for alteration minerals in hyperspectral images. The valleys and associated late‐stage deltas were formed by short‐lived aqueous processes, as suggested by their morphology and the general lack of associated aqueous alteration minerals. The likely source of water was neither widespread precipitation nor a regionally connected groundwater aquifer, but water mobilized locally from the cryosphere. Delta formation in our study areas occurred from the Early Hesperian to the Late Amazonian and did not require sustained periods of global climatic conditions favoring widespread precipitation. Liquid surface water has been locally present on Mars even after the Noachian, although only episodically, for transient intervals, and widely separated in space.
Characterization of an extremely halotolerant Staphylococcus arlettaeHPSSN35C isolated from Dwarka Beach, India
Authors: Nanjani Sandhya G. , Soni Harsha P. 
Published: July 2013

ABSTRACTAn extremely halotolerant bacterium designated as HPSSN35C was isolated from saline soil of Dwarka beach, India. It exhibited growth over a wide range of NaCl in medium varying from 0 to 6 M. The isolate produced peach–pink pigment above ∼1.3 M NaCl. The culture was characterized using biochemical tests, bioMerieux Staph identification kit, API ID32 Staph system, and Biolog. Due to slow growth and extreme salt tolerance no ID was obtained in Biolog. Antibiotic sensitivity to various antibiotics was tested. Phenotypic characterization showed that it belonged to the novobiocin resistant staphylococci group. Analysis of 16S rRNA gene sequence comparison of 1452 base pairs showed that isolate is closely related to Staphylococcus saprophyticus group with close relationship to Staphylococcus arlettae (99% similarity). The halotolerant S. arlettae described in literature till date have been reported to tolerate 4.5 M NaCl and produce white to yellow pigment. The present study reports for the first time extremely halotolerant S. arlettae exhibiting growth up to ∼6 M NaCl and producing peach–pink pigment above ∼1.3 M NaCl.
Multiple pqqA genes respond differently to environment and one contributes dominantly to pyrroloquinoline quinone synthesis
Authors: Ge Xin , Wang Wenxi , Du Baohua , Wang Jianhua , Xiong Xianghua , Zhang Weicai 
Published: July 2013

AbstractPyrroloquinoline quinone is the third redox cofactor after nicotinamide and flavin in bacteria, and its biosynthesis pathway comprise five steps initiated from a precursor peptide PqqA coded by pqqA gene. Methylovorus sp. MP688 is equipped with five copies of pqqA genes. Herein, the transcription of pqqA genes under different conditions by real‐time quantitative PCR and β‐galactosidase reporter genes are reported. Multiple pqqA genes were proved to play significant roles and contribute differently in PQQ synthesis. pqqA1, pqqA2, and pqqA4 were determined to be dominantly transcribed over the others, and correspondingly absence of any of the three genes caused a decrease in PQQ synthesis. Notably, pqqA was up‐regulated in low pH and limited oxygen environment, and it is pqqA2 promoter that could be induced when bacteria were transferred from pH 7.0 to pH 5.5. Deletion analysis revealed a region within pqqA2 promoter inhibiting transcription. PQQ concentration was increased by overexpression of pqq genes under control of truncated pqqA2 promoter. The results not only imply there exist negative transcriptional regulators for pqqA2 but also provide us a new approach to achieve higher PQQ production by deleting the target binding sequence.
Molecular characterization of the planktonic microorganisms in water of two mountain brackish lakes
Authors: Zeng Jun , Deng Li‐Juan , Lou Kai , Zhang Tao , Yang Hong‐Mei , Shi Ying‐Wu , Lin Qing 
Published: July 2013

AbstractThe prokaryotic diversity in two brackish lakes (Sayram Lake and Chaiwopu Lake) was investigated by constructing bacterial and archaeal clone libraries of 16S rRNA genes. Bacterial clones from Sayram Lake were classified into six phyla (Proteobacteria, Verrucomicrobia, Bacteroidetes, Planctomycetes, Acidobacteria, Actinobacteria). Of these, Proteobacteria and Verrucomicrobia were the most dominant, representing 50.4 and 16.8% of the clone library, respectively. Sequences related to Proteobacteria (58.1%), Cyanobacteria (17.2%), Bacteroidetes (15%), Verrucomicrobia (4.3%), Actinobacteria (3.2%) constituted over 97% of the bacterial clone library from Chaiwopu Lake. In addition, 58.8% (Sayram Lake) and 48% (Chaiwopu Lake) of bacterial clones showed high sequence identity to pure cultures. The composition of Archaea was obviously different between the two lakes. Only the Crenarchaeota phylum was found in the Sayram Lake, whereas Archaeal sequences from Chaiwopu Lake were classified into three phyla: Crenarchaeota (5.8%), Thaumarchaeota (81.2%), and Euryarchaeota (13%). Among the archaeal sequences, 94.2% were highly related to cultivable species of the genus Nitrosopumilus, Methanoculleus, and Methanobacterium. These results showed a high diversity of potential cultivable heterotrophic bacteria in Sayram Lake and Chaiwopu Lake. Chaiwopu Lake was a source of potentially novel, cultivable archaea.
Lipid mediator serum profiles in asthmatics significantly shift following dietary supplementation with omega‐3 fatty acids
Authors: Lundström Susanna L. , Yang Jun , Brannan John D. , Haeggström Jesper Z. , Hammock Bruce D. , Nair Parameswaran , O'Byrne Paul , Dahlén Sven‐Erik , Wheelock Craig E. 
Published: July 2013

ScopeIn contrast to well‐characterized PUFA levels in serum, little is known regarding their downstream metabolic products. However, many of these compounds are lipid mediators with prominent roles during pro‐ and antiinflammatory processes.Methods and resultsIn this double blind crossover study on asthmatics, shifts in serum levels of ω‐3 and ω‐6 PUFA‐derived oxidized fatty acids (e.g. eicosanoids, oxylipins) were quantified following dietary fish oil supplementation. Serum was obtained from subjects following fasting at three occasions; (i) prior to supplementation, (ii) following a 3‐week supplement intake of either placebo or fish oil, and (iii) following a 3‐week washout period with a subsequent 3‐week period of either fish oil or placebo supplement. A total of 87 oxylipins representing cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) metabolic pathways were screened via LC‐MS/MS. The primary alterations observed were in CYP‐ and 15‐LOX‐derived EPA‐ and CYP‐derived DHA oxylipins.ConclusionThe results indicate that intake of an ω‐3 rich diet alters not only the PUFA ratio, but also the ratio of downstream oxylipins. These data further support that dietary manipulation with ω‐3 PUFAs affects not only PUFA levels, but importantly also the downstream metabolic profile.
Laser‐micromachined cellulose acetate adhesive tape as a low‐cost smart material
Authors: Ochoa Manuel , Chitnis Girish , Ziaie Babak 
Published: July 2013

ABSTRACTAn off‐the‐shelf, moisture‐responsive, acetate‐backed adhesive tape is investigated as a commercially available smart material for fabricating low‐cost, multifunctional, humidity‐responsive millimeter‐scale structures. Laser ablation is used for cutting and thinning‐down the tape to enhance its response. Water‐submerged cantilevers show a radius of curvature of 3 mm or lower (for laser‐thinned cantilevers). Additionally, their humidity response is a function of the angle between the longitudinal axis of the cantilever and polymer orientation. A cut angled at 80° with respect to this orientation results in a tip rotation of up to 25°, enabling the formation of bending cantilevers with twisting behavior. The tape cantilevers are further functionalized with magnetic nanoparticles and used to create four‐finger grippers that close underwater within minutes and can sample 100 µL of liquid. A cyclic humidity monitor is also fabricated using a tape strip that walks unidirectionally on a ratchet‐shaped surface upon exposure to humidity variations. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1263–1267
Synthesis and biomimetic mineralization of l‐proline substituted polyphosphazenes as bulk and nanofiber
Authors: Silva Nykänen Virginia P. , Puska Mervi A. , Nykänen Antti , Ruokolainen Janne 
Published: July 2013

ABSTRACTThis work presents the synthesis of polyphosphazenes bearing L‐proline methyl ester (ProOMe) and 4‐hydroxy‐l‐proline methyl ester (HypOMe), aiming for new bioactive polymers for bone repair. The polymers were characterized by 1H and 31P NMR, FTIR, DSC, and TGA. Electrospun fibers were prepared using poly[bis(l‐proline methyl ester)phosphazene] (PProP), and their potential for biomimetic mineralization, as well as the bulk material, were tested in simulated body fluid (1×SBF). Samples were analyzed between 24 h and 3 weeks of incubation using SEM/EDS and FTIR. After 24 h, spherical and flower‐like shapes of calcium phosphates (CaP) were crystallized on the bulk samples. The nanofibers presented spherical CaP crystals attached to them after 48 h of incubation. The Ca/P molar ratio of the crystals varied from 1.5 to 1.6. According to this study, PProP presents bioactivity in vitro, and its fibers offer sites for CaP nucleation like the collagen fibers in bone. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1318–1327