bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantioselective Merger of Aminocatalysis with π‐Lewis Acid Metal Catalysis: Asymmetric Preparation of Carbo‐ and Heterocycles
Authors: Praveen Chandrasekaran , Montaignac Benjamin , Vitale Maxime R. , Ratovelomanana‐Vidal Virginie , Michelet Véronique
Published: July 2013

The metallo‐organocatalyzed enantioselective synthesis of various five‐membered carbo‐ and heterocyclic structures through the merger of aminocatalysis with the catalytic indium(III) or copper(I) activation of α‐disubstituted formyl alkynes is described. The use of indium trichloride associated with the (R)‐1,1′‐bis‐(2‐naphthylamine) ligand led to encouraging results with up to 85:15 enantiomeric ratio. After a careful examination of several other strategies, the best synergic catalytic system, which combines a chiral copper(I) complex with cyclohexylamine, afforded the enantioselective preparations of cyclopentane, indane, and pyrrolidine scaffolds with moderate to excellent control of the all‐carbon quaternary stereogenic centers created through such cyclization processes.
Modification of Disposable Red‐Mud Catalysts for Slurry‐Phase Hydrocracking of Vacuum Residue
Authors: Nguyen‐Huy C. , Kim H. , Kweon H. , Kim D. K. , Kim D.‐W. , Oh S. H. , Shin E. W.
Published: July 2013

A disposable iron‐based catalyst, red mud, was modified by different dissolution‐precipitation methods. The catalysts obtained were characterized by nitrogen adsorption, X‐ray diffraction, scanning electron microscopy, and ammonia temperature‐programmed desorption. They were tested for slurry‐phase hydrocracking of vacuum residue in a batch reactor. The red‐mud catalyst activated by phosphoric acid showed the highest catalytic activity since the activation by phosphoric acid resulted in the decrease in particle size which facilitated the transformation of red mud to the active sulfide form in the reaction.
Investigation of Nucleation Kinetics by Nephelometric Measurements
Authors: Parisi M. , Chianese A.
Published: July 2013

The application of a nephelometric probe for investigation of nucleation kinetics is reported. First a check of direct proportionality of the signal with respect to the surface of the solid suspension was performed, followed by an experimental analysis of the nucleation of potassium sulfate crystals from aqueous solutions by applying both polythermal and isothermal methods. The adopted instrument allowed to accurately detect the metastable zone width and the induction time and to monitor the first period of time after nucleation. These latter measurements give an indication of the overall crystal mass evolution at the starting of the crystallization operation.
Synthesis of 5,6‐Diarylpyridin‐2(1H)‐ones from Isoflavones
Authors: Zhu Mulin , Zhang Zunting , Xue Dong , Qiao Jinfeng , Liang Yong , Wnuk Stanislaw F.
Published: July 2013

A simple method for the cyclocondensation of substituted isoflavones with cyanoacetamide in the presence of sodium hydroxide to give an array of 3‐cyano‐5,6‐diarylpyridin‐2(1H)‐ones in good yields is reported.
Selective Reduction of Nitroarenes with Molybdenum Disulfide
Authors: Huang Lei , Luo Pingfei , Xiong Man , Chen Rizhi , Wang Yong , Xing Weihong , Huang Jun
Published: July 2013

Commercial MoS2 was found to be a highly selective catalyst for the reduction of nitrobenzenes to the corresponding anilines with hydrazine under mild conditions. MoS2 is not only much cheaper, but also more selective than noble metal catalysts for the reduction of functional nitrobenzenes to the corresponding anilines. Nitrobenzenes with halides (F, Cl, Br and I) were reduced selectively, and the corresponding anilines were obtained in excellent yields, and no dehalogenation was detected. Functional groups such as NH2, OH, alkene groups were tolerated during the reduction of the nitro compounds. The reduction of p‐chloronitrobenzene was studied over MoS2 and Pd/C respectively with hydrazine. The yield of p‐chloroaniline was much higher with MoS2 than that with Pd/C at full conversion.
Nickel‐Catalyzed ortho‐Selective Hydrodefluorination of N‐Containing Heterocycle‐Polyfluoroarenes
Authors: He Yi , Chen Zhao , He Chun‐Yang , Zhang Xingang
Published: July 2013

An effective and facile method for preparation of partially fluorinated aromatics via Nickel catalyzed, chelation‐assisted ortho selective hydrodefluorination of polyfluoroarnes with triethylsilane has been developed, in which N‐containing heterocycles were used as directing groups. The advantage of this protocol is its simple catalytic system with use of inexpensive and readily available NiCl2·6H2O as a catalyst.
Array languages and the N‐body problem
Authors: Cockshott P. , Gdura Y. , Keir P.
Published: July 2013

This paper is a description of the contributions to the Scottish Informatics and Computer Science Alliance Multi‐core Challenge on many body planetary simulation made by a compiler group at the University of Glasgow. Our group is part of the Computer Vision and Graphics research group, and we have for some years been developing array compilers because we think these are a good tool both for expressing graphics algorithms and for exploiting the parallelism that computer vision applications require. We shall describe experiments using two languages on two different platforms, and we shall compare the performance of these with reference C implementations running on the same platforms. Finally, we shall draw conclusions both about the viability of the array language approach as compared with other approaches used in the challenge and also about the strengths and weaknesses of the two, very different, processor architectures we used. Copyright © 2013 John Wiley & Sons, Ltd.
Iron Azides with Cyclam‐Derived Ligands: Are They Precursors for High‐Valent Iron Nitrides in the Gas Phase?
Authors: Krahe Oliver , Neese Frank , Engeser Marianne
Published: July 2013

The FeIII azide complexes [FeIII(N3)cyclam‐ac]PF6 (1⋅PF6), [FeIII(N3)Me3cyclam‐ac]PF6 (2⋅PF6), and trans‐[FeIII(N3)2cyclam]ClO4 (3⋅ClO4) (cyclam=1,4,8,11‐tetraazacyclotetradecane; cyclam‐ac=1,4,8,11‐tetraazacyclotetradecane‐1‐acetate; Me3cyclam‐ac=4,8,11‐trimethyl‐1,4,8,11‐tetraazacyclotetra‐decane‐1‐acetate) are studied in the gas phase with special emphasis on the formation of high‐valent iron nitrides by collision‐induced dissociation. Whereas the azide complex with unsubstituted cyclam‐acetate 1 as major fragmentation expels N2 to form a high‐valent FeV nitride complex, a similar process is not observed for its methyl‐substituted congener. In contrast, loss of an azide radical results in iron reduction to FeII. Thus, the gas‐phase behavior is parallel to the results obtained in spectroscopic studies of photolyzed frozen solution. The diazide complex 3 mainly fragments via consecutive losses of HN3 without change in the iron oxidation state. However, small amounts of dinitrogen loss and thus FeV nitride formation are also observed. While it is assumed that the FeV nitride complex detected by Mössbauer spectroscopy in frozen solution is still coordinated by an azide in the trans position to the nitride, both the complex [FeV(N)(N3)(cyclam)]+still bearing an intact second azide and the coordinatively unsaturated [FeV(N)(cyclam‐H)]+ are observed in the gas phase.
Mechanical properties of aluminium laminates produced by accumulative roll bonding
Authors: Chekhonin P. , Scharnweber J. , Scharnweber M. , Oertel C.‐G. , Hausöl T. , Höppel H.W. , Jaschinski J. , Marr T. , Skrotzki W.
Published: July 2013

Laminates of high and commercial purity aluminium layers were processed by accumulative roll bonding performed up to ten cycles. The mechanical properties were measured by tensile testing. Both yield strength and ultimate tensile strength increase with higher number of cycles. The fracture strain is decreased through the first ARB cycle, but increases during further processing to reach a maximum after the sixth cycle. It is found that the development of the microstructure, especially in the high purity layers, strongly influences the mechanical properties.
One‐step fabrication of SnxTi1‐xO2 rutile‐type core‐shell microspheres and their electrochemical properties
Authors: Dong Yutao , Wang Xinjun , Chen Junli , Chai Fenglan , Liu Xinqi
Published: July 2013

SnxTi1‐xO2 core‐shell microspheres were synthesized through a simple one‐step hydrothermal method. The structural and morphologic properties were unambiguously characterized, and the electrochemical performance of the SnxTi1‐xO2 microspheres was determined by cyclic voltammetry. The possible formation mechanism of SnxTi1‐xO2 microspheres was also proposed.
Differential gene expression in notochord and nerve cord fate segregation in the Ciona intestinalis embryo
Authors: Kobayashi Kenji , Yamada Lixy , Satou Yutaka , Satoh Nori
Published: July 2013

During early embryogenesis, embryonic cells gradually restrict their developmental potential and are eventually destined to give rise to one type of cells. Molecular mechanisms underlying developmental fate restriction are one of the major research subjects within developmental biology. In this article, this subject was addressed by combining blastomere isolation with microarray analysis. During the 6th cleavage of the Ciona intestinalis embryo, from the 32‐cell to the 64‐cell stage, four mother cells divide into daughter cells with two distinct fates, one giving rise to notochord precursor cells and the other to nerve cord precursors. Approximately 2,200 each of notochord and nerve cord precursor cells were isolated, and their mRNA expression profiles were compared by microarray. This analysis identified 106 and 68 genes, respectively, that are differentially expressed in notochord and nerve cord precursor cells. These included not only genes for transcription factors and signaling molecules but also those with generalized functions observed in many types of cells. In addition, whole‐mount in situ hybridization showed dynamic spatial expression profiles of these genes during segregation of the two fates: partitioning of transcripts present in the mother cells into either type of daughter cells, and initiation of preferential gene expression in either type of cells. genesis 51:647–659. © 2013 Wiley Periodicals, Inc.
2,2′‐Bipyridine and 1,10‐Phenanthroline as Coligands or Structure‐Directing Agents in Uranyl–Organic Assemblies with Polycarboxylic Acids
Authors: Thuéry Pierre
Published: July 2013

Seven uranyl complexes with polycarboxylic acids were synthesized under hydrothermal conditions in the presence of 2,2′‐bipyridine (bipy) or 1,10‐phenanthroline (phen), and their crystal structures were determined. The bipy and phen molecules are uncoordinated in the two oxalate complexes [Hbipy]2[(UO2)2(C2O4)(OH)3]2·bipy (1) and [Hphen]2[(UO2)2(C2O4)3] (2), which provide two new two‐dimensional architectures in the uranyl oxalate family. The first uranyl complexes with citraconic acid (H2citcn) could also be obtained in these conditions: [UO2(citcn)(bipy)] (3) and [UO2(citcn)(phen)] (4) are isomorphous one‐dimensional, ribbonlike polymers in which bipy and phen are terminal coligands. The complex formed with the trans,trans,trans isomer of 1,2,3,4‐cyclobutanetetracarboxylic acid (H4cbtc), [Hbipy][UO2(Hcbtc)]·1.5H2O (5), displays a two‐dimensional arrangement. One of the carboxylic groups retains its proton and is uncoordinated, in contrast to the bonding scheme in the previously reported framework with the same ligand. Bipy is a coligand in the complex with citric acid (H4cit), [(UO2)2(cit)(bipy)]·0.5H2O (6), which contains both the {[UO2(cit)]2}4– dimeric subunits frequently encountered in uranyl citrates and a third uranium centre bound to three carboxylate groups and chelated by bipy. The closely related D‐(–)‐citramalic acid (H3citml) gives the complex [Hphen]2[(UO2)5(citml)4(H2O)]·3H2O (7), a three‐dimensional framework comprising {[UO2(citml)]2}2– dimeric subunits assembled into chains, and other uranium atoms connecting four such chains. Large channels are occupied by columns of Hphen+ counterions held together by π‐stacking interactions. In these complexes, bipy and phen are either present as coligands or as counterions. In the latter case, they act as organic templates that lead to structures different from those previously known with the same carboxylate ligands.
Switch On/Switch Off Signal in an MOF‐Guest Crystalline Device
Authors: Mazzeo Paolo P. , Maini Lucia , Braga Dario , Valenti Giovanni , Paolucci Francesco , Marcaccio Massimo , Barbieri Andrea , Ventura Barbara
Published: July 2013

A metal organic framework (MOF) based on the [Cu4I4DABCO2] cluster (DABCO = 1,4‐diazabicyclo[2.2.2]octane), MOF 1, shows bright emission with a maximum at 556 nm and an emission quantum yield of 0.53 in the solid state. When the large cavities of the MOF are loaded during the synthesis with different amounts of ferrocene {FeCp2, [(η5‐C5H5)2FeII]}, the luminescence of MOF 1 decreases with the increase in the ferrocene content, reaching an almost complete quenching for 3.5 wt.‐% of cage loading, corresponding to the complete filling of the MOF cavities. When an electric potential is applied to the FeCp2@MOF 1 deposited onto an ITO glass, the FeIICp2 is oxidised to FeIIICp2+, and the MOF 1 emission is partially switched on again, indicating that a photoinduced electron‐transfer reaction is contributing to the quenching process.
Physical, chemical, and lubricant properties of Brassicaceae oil
Authors: Ratanapariyanuch Kornsulee , Clancy Johanna , Emami Shahram , Cutler Jeffery , Reaney Martin J. T.
Published: July 2013

Rapeseed oil and canola oil have traditionally been used in industrial lubricant applications but oils of many species of Brassicaceae have similar properties. Oil from the seed of seven Brassicaceae species, Sinapis alba (yellow mustard), Camelina sativa (false flax), Brassica carinata (Ethiopian mustard), B. napus (rapeseed), B. juncea (oriental mustard), B. rapa (field mustard), and S. arvensis (wild mustard), were recovered by cold pressing and filtration without further refining. The physical, chemical, and lubricant properties of the oils were determined. B. napus had the highest oil yield when extracted by cold press and B. juncea* (low erucic B. juncea) had the highest oil content extracted by solvent. C. sativa oil had the lowest sterol content, mineral content, oxidative stability, and viscosity at 40 and 100°C and had the highest iodine value among tested oils. Iodine value had a strong negative correlation with oxidative stability in the tested oils. There was not any water in any of the oil samples. Overall, C. sativa oil had properties making it suitable for use as a fuel although its low oxidative stability and high iodine value could pose challenges; however, S. alba oil was more appropriate for use as a lubricant.
Highly active biocatalyst for transesterification: Cross linked enzyme aggregates of Thermomyces lanuginosus and Candida antarctica B
Authors: Schroeck Andrea Maria , Schober Sigurd , Mittelbach Martin
Published: July 2013

The preparation of cross‐linked enzyme aggregates (CLEAs) with albumin as an additive is demonstrated successfully with lipase Thermomyces lanuginosus (TL) and lipase B of Candida antarctica (CalB). Investigations regarding the albumin admixture and the temperature optimum are employed. Compared to non‐cross‐linked lipase, CalB delivers the best results at a mass ratio of 1:16 lipase/albumin, which leads to a 24‐fold increase of activity; TL at a mass ratio of 1:12, which leads to a eightfold increased activity. A transesterification yield of 61% m/m ethyl ester can be reached with 2.5% m/m CLEAs of lipase TL applied on rapeseed oil within 1.5 h reaction time. A catalyst mass of 10% m/m yields 94% m/m ethyl ester in the same time. Within six cycles of reuse, the catalyst remains stable. CLEAs of CalB and Novozym 435 (a commercial immobilized lipase B of C. antarctica) show comparable rates in ethanolysis and glycerolysis reaction.

Practical applications: CLEAs have become of increasing interest in terms of synthesis of organic compounds via bio‐catalytic (green) approaches. The findings presented here are targeting at transesterification of fats and oils into corresponding alkyl esters applicable, e.g., as alternative fuel substitutes. High conversion rates coupled with hyperactivation effects as well as highly appealing reusability behavior indicate the practical benefits even for technical applications. Conversion of lipids into derivatives by CLEAs as demonstrated here, might extend utilization and conversion possibilities of biomass.
Evaluation of conjugated fatty acids incorporation in tilapia through GC–FID and EASI–MS
Authors: Bonafé Elton Guntendorfer , Boeing Joana Schuelter , Matsushita Makoto , Claus Thiago , de Oliveira Santos Oscar , de Oliveira Cláudio Celestino , Eberlin Marcos Nogueira , Visentainer Jesuí Vergílio
Published: July 2013

The purpose of this work was to evaluate the incorporation of conjugated linoleic and α‐linolenic fatty acids into muscle tissue of genetically modified tilapia through treatment with CLA and tung oil‐enriched diet as a source of these acids by gas chromatograph equipped with a FID (GC–FID). The results showed that conjugated fatty acids were incorporated into tilapia muscle tissue and the accumulation had higher values in fourth period, except the α‐eleostearic acid. Furthermore, other fatty acids of important nutritional value such as EPA, DHA, and AA acids were also identified in this study. Tilapia treated with diets enriched with CLA and tung oil can be included in human diet as a source of conjugated fatty acids such as conjugated linoleic and α‐linolenic acids.

Practical applications: Adding CLA and tung oil, a source of conjugated α‐linolenic acid, to tilapia feed, can significantly increase the concentration of conjugated fatty acids in tilapia muscle tissue. Tilapia fed with CLA and CLnA can be included in human diet as a source of conjugated fatty acids.
Deuterium and Tritium Labelling of N‐Acyl‐L‐homoserine Lactones (AHLs) by Catalytic Reduction of a Double Bond in the Layer‐by‐Layer Method
Authors: Jakubczyk Dorota , Merle Christian , Brenner‐Weiss Gerald , Luy Burkhard , Bräse Stefan
Published: July 2013

N‐Acyl‐L‐homoserine lactones (AHLs) are signalling molecules found in Gram‐negative bacteria that enable bacteria to communicate with each other through quorum sensing and with their eukaryotic host cells through inter‐kingdom signalling. Very little is known about inter‐kingdom signalling mechanisms. Deuterium‐ and tritium‐labelled AHLs were synthesized in an effort to detect the cellular distribution and monitor the membrane transport of AHLs. Most tritium labelling methods use tritium gas, which is difficult to handle, however, here we present a novel, gas‐free method with which to obtain deuterium‐ and tritium‐label terminally unsaturated AHLs through catalytic reduction of the double bond. This uncommon double bond reduction employs either sodium borohydride‐[2H] or sodium borohydride‐[3H] and is performed in the presence of palladium(II) acetate, which acts as a catalyst in the unique layer‐by‐layer system. Moreover, detailed NMR analysis of the resulting isotopologues is presented.
Network coding for relaying networks over double‐link rayleigh fading channels using priority in decoding
Authors: Abdollahi Mehran Pourmohammad , Biroun Payman Mahmoudi , Niya Javad Musevi
Published: July 2013

Nowadays, wireless networks are employed for many applications, but they face some problems such as power source limitation and collision due to common media. These problems decrease the network throughput and increase the power consumption. Fading is another important characteristic of wireless channels, which degrades the network performance. On the contrary, network coding is a useful method that can be applied to increase throughput. We extend the network coding model from two nodes with one relay to four nodes with the same relay over Rayleigh fading channels. Each side of the relay consists of two neighbouring nodes, which relaying nodes are not needed between them. In this paper, we propose a new method that uses priority property for decoding so that high or low priority for a node means that the node will XOR received data from relay node and its own data or data received from its neighbour, respectively. Also, decoding procedure includes two stages in which one of the neighbour nodes in each side has high priority and the other one has low priority. Then, network performance and the effects of Rayleigh fading on network coding over double‐link channels are studied under power‐constant and channel‐inversion schemes. By solving optimisation problems called Double‐Link Network Coding Constant Power and Double‐Link Network Coding Channel Inversion, we obtain optimum network throughput. The results show that the proposed method increases network throughput and decreases power consumption by reducing number of time slots in comparison with the simple method. Copyright © 2013 John Wiley & Sons, Ltd.
The pursuit of political will: politicians' motivation and health promotion
Authors: Zalmanovitch Yair , Cohen Nissim
Published: July 2013

The health promotion literature points out a significant gap between declared health promotion policy and practice. The common assumption is that one of the main obstacles to progress is “political will” and the intersectoral action necessary to create healthy environments. The concept of political will is most frequently invoked to explain a lack of action usually rooted in politicians' lack of personal courage or good sense. While stressing the fact that health and its promotion are profoundly political, we claim that the lack of political will is usually not because politicians have shown insufficient personal courage or good sense. Rather, we suggest that one of the reasons for the gap between the need for health promotion policies and political will derives from politicians' lack of attraction to several aspects associated with this policy area. In many cases, politicians are not attracted to the issue of health promotion because of the unique structural conditions usually associated with this policy domain. Using tools related to public policy theory, we suggest a conceptual framework that explains what those conditions are and answers the question of why politicians seem to lack the political will to undertake the design of health promotion policies. Copyright © 2013 John Wiley & Sons, Ltd.
Upregulation of endogenous ICAM‐1 reduces ovarian cancer cell growth in the absence of immune cells
Authors: de Groote Marloes L. , Kazemier Hinke G. , Huisman Christian , van der Gun Bernardina T.F. , Faas Marijke M. , Rots Marianne G.
Published: July 2013

Ovarian cancer is a difficult‐to‐treat cancer with a 5‐year survival rate of only ∼45%, due to late diagnosis and therapy resistance. In need of new therapeutic approaches, induction of intercellular adhesion molecule (ICAM)‐1 expression might be of interest, since the expression of ICAM‐1 is lower in ovarian cancer cells compared with healthy ovarian cells and correlated with decreased tumorigenicity. Whereas ICAM‐1 expression on tumor cells is of importance for attracting immune cells, ICAM‐1 might also induce tumorigenicity and chemoresistance. In ovarian cancer, such a role of ICAM‐1 is unclear. Here, we investigated whether ICAM‐1 has a cell‐biological role by bidirectional modulation of ICAM‐1 expression using ICAM‐targeting artificial transcription factors. For a panel of ovarian cancer cells, tumor growth and cisplatin sensitivity were evaluated. Induction of ICAM‐1 expression (ranging from 3‐ to 228‐fold on mRNA level and 1.7‐ to 108‐fold on protein level) resulted in indications of decreased ovarian cancer cell growth and reduced cisplatin sensitivity. Repression ranged from 48 to 94% on mRNA level and 47 to 91% on protein level. This study shows that, next to its established immunogenic role, ICAM‐1 affects cell biological behavior of ovarian cancer cells and, importantly, that reexpression by artificial transcription factors represents a powerful approach for functional validation of genes epigenetically silenced in cancer, such as ICAM‐1.
Perceptual weighting of pain behaviours of others, not information integration, varies with expertise
Authors: Prigent E. , Amorim M.‐A. , Leconte P. , Pradon D.
Published: July 2013

Background

Being able to estimate effort pain in patients is important for health care providers working in physical rehabilitation services. Previous studies have shown that clinicians and physiotherapists underestimate patients' pain.

Methods

The present study examined how two sources of visual information, namely body kinematics (movement speed and postural constraints) and facial expressions are integrated in order to estimate effort pain magnitude experienced by a paraplegic person performing a sitting pivot transfer. In addition, the effect of familiarity with paraplegia on judgment was assessed by comparing performance among physiotherapists, paraplegic patients and unfamiliar participants. Functional measurement was used to determine the psychophysical law of visual information integration carried by pain behaviours (guarding and facial expression).

Results

 Results indicate that guarding behaviour (specified by movement speed) carried important information for perceived effort pain independently of familiarity. In contrast, facial expression of pain was relevant only to unfamiliar and physiotherapist participants and not to paraplegic participants. Even if physiotherapists underestimated effort pain as compared to the other groups, they relied more strongly on facial expression, than other participants, in their estimation of effort pain expressed by a paraplegic patient.

Conclusions

These results bring further insights into understanding physiotherapists' perception of patients' pain. In order to improve their ability to adapt the difficulty of the rehabilitation sessions, they should learn to raise their global level of pain magnitude estimation (for example, by performing themselves the body movement) instead of overweighting facial pain expression signals.
Monitoring caffeine and resveratrol cutaneous permeation by confocal Raman microspectroscopy
Authors: Tfaili Sana , Josse Gwendal , Angiboust Jean‐François , Manfait Michel , Piot Olivier
Published: July 2013

Dynamic follow‐up of exogenous molecules permeation through the skin is one among many competing applications for confocal Raman microspectroscopy. Previous studies showed the feasibility of tracking actives through the skin; the next step should be recording in vivo kinetics. Thus, we conducted a study to evaluate the possibility of detecting low concentrations of caffeine and resveratrol solutions through the skin using confocal Raman microspectroscopy. After topical application of each active on the skin surface, Raman profiles were recorded over nine hours. The challenge was to pursuit these actives respecting the concentration used in some dermatological formulations. Molecules were successfully detected and kinetic profiles were registered over time. The heterogeneity of skin structure and the complexity of molecules diffusion were reflected through the kinetic results. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Propagation of internal tides generated near Luzon Strait: Observations from autonomous gliders
Authors: Rainville Luc , Lee Craig M. , Rudnick Daniel L. , Yang Kai‐Chieh
Published: July 2013

The vertical isopycnal displacements associated with internal waves generated by the barotropic tidal currents in the vicinity of Luzon Strait are estimated using measurements collected by autonomous underwater gliders. Nearly 23,000 profiles from Seagliders and Spray gliders, collected during 29 different missions since 2007, are used to estimate the amplitude and phase of the linear semidiurnal and diurnal internal waves in this energetic region, particularly in the previously poorly sampled area near the eastern ridge and on the Pacific side of Luzon Strait. The mean and variability of the internal wave field in the upper 1000 m of the water column are described. The phase progression of internal waves as they propagate away from their generation sites is captured directly. The glider‐based observations are used to map the mode‐1 semidiurnal and diurnal internal wave fields, providing the baroclinic energy flux over a roughly 600 km × 800 km region based strictly on in situ observations.
Revisiting internal waves and mixing in the Arctic Ocean
Authors: Guthrie John D. , Morison James H. , Fer Ilker
Published: July 2013

To determine whether deep background mixing has increased with the diminishment of the Arctic sea ice, we compare recent internal wave energy and mixing observations with historical measurements. Since 2007, the North Pole Environmental Observatory has launched expendable current probes (XCPs) as a part of annual airborne hydrographic surveys in the central Arctic Ocean. Mixing in the upper 500 m is estimated from XCP shear variance and Conductivity‐Temperature‐Depth (CTD) derived Brunt‐Väisälä frequency. Internal wave energy levels vary by an order of magnitude between surveys, although all surveys are less energetic and show more vertical modes than typical midlatitude Garrett‐Munk (GM) model spectra. Survey‐averaged mixing estimates also vary by an order of magnitude among recent surveys. Comparisons between modern and historical data, reanalyzed in identical fashion, reveal no trend evident over the 30 year period in spite of drastic diminution of the sea ice. Turbulent heat fluxes are consistent with recent double‐diffusive estimates. Both mixing and internal wave energy in the Beaufort Sea are lower when compared to both the central and eastern Arctic Ocean, and expanding the analysis to mooring data from the Beaufort Sea reveals little change in that area compared to historical results from Arctic Internal Wave Experiment. We hypothesize that internal wave energy remains lowest in the Beaufort Sea in spite of dramatic declines in sea ice there, because increased stratification amplifies the negative effect of boundary layer dissipation on internal wave energy.
Estimating the Bowen ratio over the open and ice‐covered ocean
Authors: Andreas Edgar L , Jordan Rachel E. , Mahrt Larry , Vickers Dean
Published: July 2013

The Bowen ratio, the ratio of the turbulent surface fluxes of sensible (Hs) and latent (HL) heat, Bo ≡ Hs/HL, occurs throughout micrometeorology. It finds application in the Bowen ratio and energy budget method, where it provides both turbulent heat fluxes when only the available energy at the surface is known. It can yield an estimate of a missing Hs or HL if the other flux is known. We also suggest that the Bowen ratio may provide the missing piece needed to infer the surface sensible heat flux from satellite data. For this study, we analyze almost 9000 eddy‐covariance measurements of Hs and HL. About half were made over sea ice; the other half, over the open ocean. These are saturated surfaces where the surface specific humidity is the saturation value at the surface temperature. Surface temperatures ranged from −44°C to 32°C and predict the Bowen ratio through the Bowen ratio indicator,
. Here cp is the specific heat of air at constant pressure, Lv is the latent heat of sublimation or vaporization, and
is the derivative of the saturation specific humidity (Qsat) with temperature (Θ). All quantities are evaluated at the surface temperature, Θs. Although Hs and HL can occur in nine possible combinations, in our data set, three combinations represent over 90% of the cases: Hs > 0 and HL > 0, Hs < 0 and HL < 0, and Hs < 0 and HL > 0. In each of these three cases, the data suggest
, where a is 0.40, 3.27, and −0.65, respectively.
Directional short wind wave spectra derived from the sea surface photography
Authors: Yurovskaya M. V. , Dulov V. A. , Chapron B. , Kudryavtsev V. N.
Published: July 2013

New field measurements of 2‐D wave number short wind wave spectra in the wavelength range from few millimeters to few decimeters are reported and discussed. The measurement method is based on stereophotography and image brightness contrast processing. As found, the spectra of decimeter waves are almost isotropic and weakly dependent on the wind speed. Both directional anisotropy and wind sensitivity rapidly increase at wave numbers larger than 100 rad/m. These aspects are consistent with other previously reported optical and radar data. Following these new in situ measurements, a revision of a semiempirical model of short wind wave spectrum is suggested. This revised model can readily be implemented in other studies (radar scattering, air‐sea interaction issues) where detailed knowledge of short wind wave spectra is crucial.
River flow controls on tides and tide‐mean water level profiles in a tidal freshwater river
Authors: Sassi M. G. , Hoitink A. J. F.
Published: July 2013

Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal‐mean friction in the river, which may act as a barrier to the river discharge. Time series of tidal water level amplitudes at five gauge stations along the River Mahakam in Indonesia, and tidal flow velocity amplitudes at a discharge monitoring station were obtained applying wavelet analysis. Temporal variations in tidal damping coefficients for quaterdiurnal, semidiurnal, and diurnal tidal species were quantified from the observed amplitude profiles. The analysis shows that tidal damping during the rising limb of a discharge wave differs from damping during the falling limb. Wavelet cross‐correlations between surface levels yielded empirical estimates of wave numbers. An empirical relation between tidal damping and river flow is derived to describe subtidal bottom friction along an idealized tidal river resembling the Mahakam. The subtidal friction is decomposed into contributions from the river flow only, from river‐tide interaction, and from tidal asymmetry. Even for high river flow and low tidal velocity, river flow enhances friction attributed to river‐tide interaction, causing subtidal water level setup. A simple multilinear regression model using subtidal bottom friction is employed to predict subtidal water levels at locations upstream, with a relatively good agreement between predictions and observations. The explicit expression shows the nonlinear dependence of subtidal friction on river flow velocity, explaining the complex behavior of tidal‐mean surface level profiles.
Getz Ice Shelf melting response to changes in ocean forcing
Authors: Jacobs S. , Giulivi C. , Dutrieux P. , Rignot E. , Nitsche F. , Mouginot J.
Published: July 2013

The large and complex Getz Ice Shelf extends along nearly half of the West Antarctic coastline in the Amundsen Sea and is exposed to a more variable ocean environment than most other Pacific sector ice shelves. Ocean temperature, salinity, and dissolved oxygen profiles acquired near its sub‐ice cavity openings are used here to estimate seawater transports and meltwater fractions. More complete coverage during 2000 and 2007 brackets most of the variability observed from 1994 to 2011, and yearlong records near one ice front support the use of summer profiles to determine annual basal melt rates. We find area average rates of 1.1 and 4.1 m/yr, higher in 2007 when a larger volume of warmer deep water occupied the adjacent continental shelf, and the ocean circulation was stronger. Results are consistent with changes in thermocline depths relative to ice shelf draft and mass transports onto the adjacent continental shelf. We also calculate steady state and actual melting of 2.5 and 4.6 m/yr in 2007–2008 from satellite measurements of ice flux, modeled accumulation, and thinning from 2003 to 2008. This implies a positive mass balance in 2000, but negative in 2007, when the Getz was producing more meltwater than any of the larger, slower melting or smaller, faster‐melting ice shelves.
Contrast enhanced CT attenuation correlates with the GAG content of bovine meniscus
Authors: Lakin Bejamin A. , Grasso Daniel J. , Stewart Rachel C. , Freedman Jonathan D. , Snyder Brian D. , Grinstaff Mark W.
Published: July 2013

We determined whether contrast‐enhanced computed tomography (CECT) attenuation obtained using a µCT scanner correlated with the glycosaminoglycan (GAG) content and distribution in ex vivo bovine menisci. Bovine samples were immersed in different concentrations of the contrast agents CA4+ and Ioxaglate, and the µCT images were compared to Safranin‐O staining. CA4+ and Ioxaglate diffusion‐in kinetics and the correlation between their CECT attenuations and GAG content were investigated. CA4+ and Ioxaglate both reached steady state in the meniscal regions within 95 h, with tau values of 20.6 ± 3.98 and 25.9 ± 3.71 h (mean ± SD), respectively. Both agents diffused preferentially through the proximal and secondarily through the distal surface. The CA4+ CECT attenuation was strongly and positively correlated with the GAG content of the meniscus regions (R2 = 0.89, p < 0.001) at low concentrations (12 mgI/ml), while the Ioxaglate CECT attenuation was moderately and negatively correlated with the GAG content (R2 = 0.51, p = 0.03) at 60 mgI/ml. CECT can image ex vivo menisci, and the CA4+, compared to Ioxaglate, enhanced attenuation strongly correlates with the GAG content and distribution in bovine meniscus. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1765–1771, 2013
Poly(L‐aspartamide)‐Based Reduction‐Sensitive Micelles as Nanocarriers to Improve Doxorubicin Content in Cell Nuclei and to Enhance Antitumor Activity
Authors: Cui Can , Xue Ya‐Nan , Wu Ming , Zhang Yang , Yu Ping , Liu Lei , Zhuo Ren‐Xi , Huang Shi‐Wen
Published: July 2013

A reduction‐sensitive graft polymer PHEA‐S‐S‐C16 with poly{α,β‐[N‐(2‐hydroxyethyl)‐L‐aspartamide]} (PHEA) as a backbone and a disulfide‐containing alkyl as a side chain (HOOC‐S‐S‐C16) is synthesized and evaluated for intracellular DOX delivery. PHEA‐S‐S‐C16 can self‐assemble into micelles in aqueous media and load DOX at a total content of 7.3%. In vitro release studies reveal that the release rate of DOX from PHEA‐S‐S‐C16 micelles is accelerated in the presence of DTT. The results of cell experiments indicate that DOX‐loaded mPEG‐S‐S‐C16 micelles can achieve rapid DOX release in HeLa cells, as compared with their reduction‐insensitive counterparts. Endocytosis inhibition analysis indicates that PHEA‐S‐S‐C16 micelles entered cells mainly via clathrin‐mediated endocytosis.
2D Self‐Assembly of an Amido‐Ended Hydrophilic Hyperbranched Polyester by Copper Ion Induction
Authors: Li Junna , Zhang Daohong , Li Shunhai , Xu Zhicai , Chen Sufang , Li Tingcheng , Zhang Junheng , Chen Shenghui , Zhang Aiqing
Published: July 2013

The self‐assembly of an amido‐ended hydrophilic hyperbranched polyester (HTDA‐2) into ordered, compact, 2D, tree‐like structures with a diameter of over 500 μm and a trunk‐width of about 3–5 μm by the induction effect of cupric ions is presented. Influencing factors on the morphology of the self‐assemblies, including temperature, time, solvents, concentration, and humidity, investigated by polarizing optical microscopy (POM) and scanning electron microscopy (SEM), are discussed. The self‐assembly mechanism is analyzed by X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), SEM, and Fourier transform IR (FTIR) spectroscopy. A dimension (Df) of about 1.50 for the perfect fractal behavior and the crystal behavior of the self‐assemblies are determined.

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Fluorene/Carbazole Alternating Copolymers Tethered with Polyhedral Oligomeric Silsesquioxanes: Synthesis, Characterization, and Electroluminescent Properties
Authors: Xie Nana , Wang Jinze , Guo Zhilong , Chen Guangxin , Li Qifang
Published: July 2013

A series of novel fluorene/carbazole alternating copolymers tethered with polyhedral oligomeric silsesquioxanes (POSS), which have well‐defined architectures and similar polymerization degrees, are synthesized by the Heck coupling reaction to investigate the effects of the number and the position of POSS on the optoelectronic properties. The introduction of POSS results in blue shifts in the photoluminescence (PL) emission spectra (especially for P2) and improved thermal spectral stability. Moreover, an appropriate amount of POSS is beneficial for enhancing the electroluminescent properties, and a better performance is obtained when POSS units are tethered to the 9‐position of the carbazole units, rather than fluorene units. Moreover, POSS facilitates the balance of electron and hole fluxes.

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Studies on anti‐periodic boundary value problems for two classes of special second order impulsive differential equations
Authors: Shi Peilin , Dong Lingzhen
Published: July 2013

We consider anti‐periodic boundary value problems for two classes of special second order impulsive differential equations. On the basis of several important impulsive differential inequalities, by using the monotone iterative technique coupled with lower and upper solutions, we obtain sufficient conditions to guarantee the existence and uniqueness of solutions for such problems. Further, we give two examples to illustrate our conclusions. Copyright © 2013 John Wiley & Sons, Ltd.
Layout design of rockbolts for natural ground reinforcement
Authors: Kato Junji , Ishii Keiichiro , Terada Kenjiro , Kyoya Takashi
Published: July 2013

The present study addresses a layout design of rockbolts for reinforcing natural ground structures applying a special optimization method, called multiphase layout optimization. Rockbolts are used to tighten loosed natural ground, and the layout of rockbolts are determined without sufficient information about the physical properties of the ground materials. Because of this uncertainty, unexpected deformation often occurs at the excavation surface of natural ground. In that case, it is requested to determine an effective layout of the additional rockbolts promptly with respect to the actual deformation at the construction site. However, it is not easy to determine the optimal layout because of its complexity, and consequently, it has no choice but to determine the layout in an empirical way.

This study introduces a numerical approach to determine an optimal layout of rockbolts with respect to arbitrarily possible deformation of natural ground. The objective is to maximize the stiffness of the overall ground structure reinforced with rockbolts. For optimization, a gradient‐based optimization scheme is applied because of its numerical efficiency. It was verified from a series of numerical examples that this method has great potential to improve the stiffness of the overall ground structure and shows a certain applicability to a practical design. Copyright © 2013 John Wiley & Sons, Ltd.
Central nervous targets for the treatment of bladder dysfunction
Authors: Yoshimura Naoki , Miyazato Minoru , Kitta Takeya , Yoshikawa Satoru
Published: July 2013

Background

The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the urinary bladder, urethra, and external urethral sphincter. This activity is in turn controlled by neural circuits in the brain, spinal cord, and peripheral ganglia.

Aims

This paper will review recent advances in our understanding of the pathophysiology of voiding disorders, especially focusing on the central nervous system.

Methods

Various neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin, excitatory and inhibitory amino acids, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in the neural regulation of the lower urinary tract.

Results

Injuries or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce voiding dysfunctions such as urinary frequency, urgency, or incontinence.

Conclusion

We discuss the potential targets in the central nervous system and new modalities for the treatment of voiding dysfunction. Neurourol. Urodynam. 33:59–66, 2014. © 2013 Wiley Periodicals, Inc.
Multiple‐echo diffusion tensor acquisition technique (MEDITATE) on a 3T clinical scanner
Authors: Baete Steven H. , Cho Gene , Sigmund Eric E.
Published: July 2013

This article describes the concepts and implementation of an MRI method, the multiple‐echo diffusion tensor acquisition technique (MEDITATE), which is capable of acquiring apparent diffusion tensor maps in two scans on a 3T clinical scanner. In each MEDITATE scan, a set of RF pulses generates multiple echoes, the amplitudes of which are diffusion weighted in both magnitude and direction by a pattern of diffusion gradients. As a result, two scans acquired with different diffusion weighting strengths suffice for accurate estimation of diffusion tensor imaging (DTI) parameters. The MEDITATE variation presented here expands previous MEDITATE approaches to adapt to the clinical scanner platform, such as exploiting longitudinal magnetization storage to reduce T2 weighting. Fully segmented multi‐shot Cartesian encoding is used for image encoding. MEDITATE was tested on isotropic (agar gel), anisotropic diffusion phantoms (asparagus) and in vivo skeletal muscle in healthy volunteers with cardiac gating. Comparisons of accuracy were performed with standard twice‐refocused spin echo (TRSE) DTI in each case and good quantitative agreement was found between diffusion eigenvalues, mean diffusivity and fractional anisotropy derived from TRSE DTI and from the MEDITATE sequence. Orientation patterns were correctly reproduced in both isotropic and anisotropic phantoms, and approximately for in vivo imaging. This illustrates that the MEDITATE method of compressed diffusion encoding is feasible on the clinical scanner platform. With future development and employment of appropriate view‐sharing image encoding, this technique may be used in clinical applications requiring time‐sensitive acquisition of DTI parameters such as dynamical DTI in muscle. Copyright © 2013 John Wiley & Sons, Ltd.
Aspects of short‐term probabilistic blending in different weather regimes
Authors: Kober K. , Craig G. C. , Keil C.
Published: July 2013

This study explores the potential of regime‐dependent approaches to improve short‐range precipitation forecasts. Probabilistic forecasts have been generated from the radar nowcaster Radar Tracking and Monitoring (Rad‐TRAM) and the convection‐permitting weather prediction model of the Consortium for Small‐scale Modeling, Deutscher Wetterdienst (COSMO‐DE) using the neighbourhood method for a 99 day period during summer 2009. The convective adjustment time‐scale was used to classify the days of the investigated period into stratiform, equilibrium and non‐equilibrium convection regimes. The COSMO‐DE forecasts were calibrated using the reliability diagram method and blended with the nowcasts using an additive weighting, where the weighting function varies with lead time according to the time evolution of the conditional square root of ranked probability score (CSRR). The examination of two case studies showed large differences in the calibration and weighting functions for different regimes. Over the entire period, regime‐dependent calibration was found to produce large improvements in reliability in comparison with the uncalibrated forecasts; however, the results were only modestly better than with a single calibration function. The blending procedure successfully combined the nowcast and forecast information, in the sense that the blended forecast was as good as either of the two components, but there was no further gain expected from regime‐dependent weighting if regime‐dependent calibration had already been performed.