A TBP/BTBP-based GANEX Separation ProcessPart 2: Ageing, Hydrolytic, and Radiolytic Stability

Czech Academy of Sciences Publication Activity Database

Aneheim, E.; Ekberg, C.; Fermvik, A.; Foreman, M.R.S.J.; Grüner, Bohumír; Hájková, Zuzana; Kvíčalová, Magdalena

2011-01-01

Roč. 29, č. 2 (2011), s. 157-175 ISSN 0736-6299 Grant - others:EUROPEAN COMMISSION(XE) FP7-CP-2007-211267 Institutional research plan: CEZ:AV0Z40320502 Keywords : GANEX * BTBP * TBP * radiolysis * hydrolysis Subject RIV: CA - Inorganic Chemistry Impact factor: 2.024, year: 2011

Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

International Nuclear Information System (INIS)

Distler, P.; Spendlikova, I.; John, J.; Czech Technical Univ., Prague; Harwood, L.M.; Hudson, M.J.; Lewis, F.W.

2012-01-01

Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe 4 -BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO 3 , 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO 3 , 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, D Am and SF Am/Eu decreased in the order of alkyl substitution 2 > 4 ∝ 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

Demonstration of innovative partitioning processes for minor actinide recycling from high active waste solutions

International Nuclear Information System (INIS)

Modolo, G.; Wilden, A.; Geist, A.; Malmbeck, R.; Taylor, R.

2014-01-01

The recycling of the minor actinides (MA) using the Partitioning and Transmutation strategy (P and T) could contribute significantly to reducing the volume of high level waste in a geological repository and to decreasing the waste's longterm hazards originating from the long half-life of the actinides. Several extraction processes have been developed worldwide for the separation and recovery of MA from highly active raffinates (HAR, e.g. the PUREX raffinate). A multi-cycle separation strategy has been developed within the framework of European collaborative projects. The multi-cycle processes, on the one hand, make use of different extractants for every single process. Within the recent FP7 European research project ACSEPT (Actinide reCycling by SEParation and Transmutation), the development of new innovative separation processes with a reduced number of cycles was envisaged. In the so-called 'innovative SANEX' concept, the trivalent actinides and lanthanides are co-extracted from the PUREX raffinate by a DIAMEX like process (e.g. TODGA). Then, the loaded solvent is subjected to several stripping steps. The first one concerns selectively stripping the actinides(III) with selective water-soluble ligands (SO3-Ph-BTB), followed by the subsequent stripping of trivalent lanthanides. A more challenging route studied also within our laboratories is the direct actinide(III) separation from a PUREX-type raffinate using a mixture of CyMe 4 BTBP and TODGA as extractants, the so-called One cycle SANEX process. A new approach, which was also studied within the ACSEPT project, is the GANEX (Grouped ActiNide EXtraction) concept addressing the simultaneous partitioning of all transuranium (TRU) elements for their homogeneous recycling in advanced generation IV reactor systems. Bulk uranium is removed in the GANEX 1st cycle, e.g. using a monoamide extractant and the GANEX 2nd cycle then separates the TRU. A solvent composed of TODGA + DMDOHEMA in kerosene has been shown to

Modelling of innovative SANEX process mal-operations

International Nuclear Information System (INIS)

McLachlan, F.; Taylor, R.; Whittaker, D.; Woodhead, D.; Geist, A.

2016-01-01

The innovative (i-) SANEX process for the separation of minor actinides from PUREX highly active raffinate is expected to employ a solvent phase comprising 0.2 M TODGA with 5 v/v% 1-octanol in an inert diluent. An initial extract / scrub section would be used to extract trivalent actinides and lanthanides from the feed whilst leaving other fission products in the aqueous phase, before the loaded solvent is contacted with a low acidity aqueous phase containing a sulphonated bis-triazinyl pyridine ligand (BTP) to effect a selective strip of the actinides, so yielding separate actinide (An) and lanthanide (Ln) product streams. This process has been demonstrated in lab scale trials at Juelich (FZJ). The SACSESS (Safety of Actinide Separation processes) project is focused on the evaluation and improvement of the safety of such future systems. A key element of this is the development of an understanding of the response of a process to upsets (mal-operations). It is only practical to study a small subset of possible mal-operations experimentally and consideration of the majority of mal-operations entails the use of a validated dynamic model of the process. Distribution algorithms for HNO_3, Am, Cm and the lanthanides have been developed and incorporated into a dynamic flowsheet model that has, so far, been configured to correspond to the extract-scrub section of the i-SANEX flowsheet trial undertaken at FZJ in 2013. Comparison is made between the steady state model results and experimental results. Results from modelling of low acidity and high temperature mal-operations are presented. (authors)

Separation of An(III) from PUREX raffinate as an innovative SANEX process based on a mixture of TODGA/TBP

International Nuclear Information System (INIS)

Sypula, Michal; Wilden, Andreas; Schreinemachers, Christian; Modolo, Giuseppe

2010-01-01

Within the ACSEPT project, an innovative SANEX process based on TODGA/TBP for selective An(III) separation from PUREX raffinate was studied. Oxalic acid usually used for Zr complexation is considered a weak point. An investigation to substitute oxalic acid with a different masking agent was carried out. A new masking agent already studied in FZJ was applied and showed good complexation properties towards Zr and Pd. Re-investigation of the formula of the actinide stripping solution was also performed. Good separation of Ln over Am was obtained by means of DTPA and malic acid. Glycine appeared to be the strongest within the tested buffers. (authors)

The separation of extractants implemented in the DIAMEX-SANEX process

Energy Technology Data Exchange (ETDEWEB)

Heres, Xavier [CEA-Marcoule, DEN/MAR/DRCP/SCPS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Baron, P.; Hill, C.; Ameil, E.; Martinez, I. [CEA-Marcoule, DEN/MAR/DRCP/SCPS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Rivalier, P. [CEA-Marcoule, DEN/MAR/DTEC/SGCS, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France)

2008-07-01

DIAMEX-SANEX is a process developed at the Cea to recover selectively the actinides(III) after a COEX{sup TM} or a PUREX process, in order to significantly decrease the radiotoxicity of the ultimate waste produced by the nuclear industry. This liquid-liquid extraction process is based on the DIAMEX process, using a malonamide supplemented by an acidic extractant. Besides an actinide extraction step and a lanthanide stripping step are implemented an actinide(III) stripping step and an extractant splitting step. The latter is carried out to avoid interactions between these two extractants during the first co-extraction step of the actinides and the lanthanides. This paper gives some results obtained with di-n-hexyl phosphoric acid (HDHP), which fulfills the required criteria for process development. Batch experiments or cold counter-current tests showed that it is possible to separate this extractant from DMDOHEMA. HDHP can moreover maintain the lanthanides(III) in the organic phase when the actinides(III) are back extracted from the organic phase. (authors)

The separation of extractants implemented in the DIAMEX-SANEX process

International Nuclear Information System (INIS)

Heres, Xavier; Baron, P.; Hill, C.; Ameil, E.; Martinez, I.; Rivalier, P.

2008-01-01

DIAMEX-SANEX is a process developed at the Cea to recover selectively the actinides(III) after a COEX TM or a PUREX process, in order to significantly decrease the radiotoxicity of the ultimate waste produced by the nuclear industry. This liquid-liquid extraction process is based on the DIAMEX process, using a malonamide supplemented by an acidic extractant. Besides an actinide extraction step and a lanthanide stripping step are implemented an actinide(III) stripping step and an extractant splitting step. The latter is carried out to avoid interactions between these two extractants during the first co-extraction step of the actinides and the lanthanides. This paper gives some results obtained with di-n-hexyl phosphoric acid (HDHP), which fulfills the required criteria for process development. Batch experiments or cold counter-current tests showed that it is possible to separate this extractant from DMDOHEMA. HDHP can moreover maintain the lanthanides(III) in the organic phase when the actinides(III) are back extracted from the organic phase. (authors)

Physico chemical properties of irradiated i-SANEX diluents

Directory of Open Access Journals (Sweden)

Mossini Eros

2015-12-01

Full Text Available The development of effective processes to recover minor actinides from spent nuclear fuel cannot leave out of consideration the evaluation of the impact of ionizing radiations on safety, fluid dynamics and extraction efficiency. It is common knowledge from the literature that radiation damage mainly affects the diluents and, indirectly, the extractants [1], but a lack of knowledge remains regarding the radiolytic behavior of innovative selective actinide extraction (i-SANEX diluents [2, 3]. As natural prosecution of the work already performed on diluted nitric acid solutions [4], 0.44 M nitric acid solutions were irradiated in contact with a mixture of kerosene + 5 vol.% 1-octanol by a Co-60 source at 2.5 kGy/h dose rate and up to 100 kGy absorbed dose, conditions of interest for the future industrial facility. Density, viscosity, acidity, nitrate anion concentration and phase transfers were systematically measured before and after γ-irradiation. This was performed because radiation-induced modifications of these parameters may induce alterations of both the fluid dynamics and the separation performances of the extracting system. The results suggest that the fluid-dynamics of the system should be unaltered. In fact, only slight alterations of the organic phase viscosity and of the aqueous phase acidity were measured after irradiation, suggesting the occurrence of limited phase transfers and of diluent by-products formation.

Solvation and complexation study by fluorescence spectroscopy of Eu(III) and Cm(III) ions in octanol solution and at the interface with water

International Nuclear Information System (INIS)

Vu, T.H.

2008-01-01

Polydentate N-donors ligands like bis-triazine-pyridine (BTP) and bis-triazine-bis-pyridine (BTBP) can selectively extract minor actinides (III) from lanthanides (III) ions and therefore have been studied in the field of nuclear waste reprocessing. The aim of the researches carried out during this thesis is a better description of this family in biphasic systems: speciation in the organic phase and around the interfacial area. After an exhaustive description of the solvation of europium(III) cation in mixed solutions n-octanol water with TRLIF spectrometry, the complexation with nitrogen ligands iPr-BTP, C5-BTBP and CyMe4-BTBP has been studied by TRLIF and ESI-MS techniques. For each compound, the inner sphere of europium has been described and the conditional stability constants determined. The composition of the organic medium, and particularly the hydration degree of n-octanol, has an impact on the nature and the ratio of species 'cation - counter ion - ligand - water'. With high water content (representative of extraction systems), the complexes observed with Cm(III) and Eu(III) have the same stoichiometry but the affinity towards the curium cation is higher and consistent to separation factors measured with biphasic systems. The method TIRF (total internal reflection fluorescence) was retained to study the behaviour of europium(III) inside the interfacial area. Fluorescence spectra of europium have been obtained but side signals and the high depth resolution of detection lead to difficulty in obtaining the signal of interfacial europium alone. The selected technique remains promising but some improvements need to be implemented for forthcoming measurement at liquid/liquid interface. (author) [fr

Innovative SANEX process for trivalent actinides separation from PUREX raffinate

International Nuclear Information System (INIS)

Sypula, Michal

2013-01-01

Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF Ln/Am obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as a Zr

Innovative SANEX process for trivalent actinides separation from PUREX raffinate

Energy Technology Data Exchange (ETDEWEB)

Sypula, Michal

2013-07-01

Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

Linear uranium metallocenes with polydentate aromatic nitrogen ligands

Energy Technology Data Exchange (ETDEWEB)

Berthet, Jean-Claude; Thuery, Pierre; Ephritikhine, Michel [CEA, DSM/IRAMIS, UMR 3299 CEA/CNRS SIS2M, 91191, Gif-sur-Yvette (France); Maynadie, Jerome [CEA ValRho, DEN/MAR/ICSM/LCPA, 30207 Bagnols-sur-Ceze (France)

2010-07-01

Treatment of [Cp{sub 2}*U(NCMe){sub 5}]X{sub 2} [Cp* = C{sub 5}Me{sub 5}, X = BPh{sub 4} (1) or I (1')] or Cp{sub 2}*UI{sub 2} in acetonitrile with the polydentate aromatic nitrogen bases phen, terpy and R{sub 4}btbp led to the formation of the linear uranium metallocenes [Cp{sub 2}*U(NCMe){sub 3}(phen)]X{sub 2} [X = BPh{sub 4} (2), I (2')], [Cp{sub 2}*U(NCMe){sub 2}(terpy)][BPh{sub 4}]{sub 2} (4), [Cp{sub 2}*U(NCMe)(Me{sub 4}btbp)][BPh{sub 4}]{sub 2} (5) and [Cp{sub 2}*U(NCMe)(CyMe{sub 4}btbp)][X]{sub 2}, [X = BPh{sub 4} (6), I (6')], [phen 1, 10-phenanthroline, terpy = 2, 2':6, 2''-terpyridine, Me{sub 4}btbp 6, 6'-bis-(3, 3, 6, 6-tetramethyl-1, 2, 4-triazin-3-yl)-2, 2'-bipyridine, CyMe{sub 4}btbp = 6, 6'-bis-(3, 3, 6, 6-tetramethyl-cyclohexane-1, 2, 4-triazin-3-yl)-2, 2'-bipyridine]. The bent metallocene [Cp{sub 2}*U(phen){sub 2}][BPh{sub 4}]{sub 2} (3) was isolated from the reaction of 1 and two molar equivalents of phen in THF. The X-ray crystal structures of 2.2MeCN, 3.2THF, 4 and 6'center dot 2MeCN were determined. (authors)

An insight into the complexation of trivalent americium vis-a-vis lanthanides with bis(1,2,4-triazinyl)bipyridine derivatives

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, Arunasis; Mohapatra, Manoj; Mohapatra, Prasanta K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Radiochemistry Div.; Gadly, Trilochan; Ghosh, Sunil K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Bioorganic Div.; Manna, Debashree; Ghanty, Tapan K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Theoretical Chemistry Section; Rawat, Neetika; Tomar, Bhupendra S. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Radioanalytical Chemistry Div.

2017-01-26

Complexation of Am{sup 3+} and Ln{sup 3+} (La{sup 3+}, Eu{sup 3+}, and Er{sup 3+}) with two bis(1,2,4-triazinyl)bipyridine (C{sub 2}BTBP, C{sub 5}BTBP) derivatives has been studied in acetonitrile medium with use of various experimental techniques such as electrospray ionization mass spectrometry (ESI-MS), time-resolved fluorescence spectroscopy (TRFS), UV/Vis spectrophotometry, and solution calorimetry. Metal-ligand stoichiometries and conditional stability constants of these complexes were determined. To the best of our knowledge, this is the first report on the complexation of Am{sup 3+} with any of the BTBP derivatives with use of UV/Vis spectrophotometric titration to determine the conditional stability constants. Density functional theory (DFT) calculations are carried out on the An{sup 3+} (U{sup 3+} and Am{sup 3+}) and Ln{sup 3+} (La{sup 3+}, Nd{sup 3+}, Eu{sup 3+}, Er{sup 3+}, and Lu{sup 3+}) complexes of BTBP in order to understand the difference between the bonding in actinide and lanthanide complexes. The results indicate a stronger covalent interaction in the An-N bonds as compared to the Ln-N bonds, which leads to an actinide selectivity of this class of ligands. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Neutral bidentate N-heterocyclic ligands - phase transfer reagents improving the kinetics of solvent extraction of Am(III) and Eu(III) ions with tetradentate 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine

International Nuclear Information System (INIS)

Narbutt, J.; Krejzler, J.

2008-01-01

Poor kinetics of solvent extraction of Am(III) and Eu(III) ions from 1 M HNO 3 with 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (etBTBP) has been improved by adding an auxiliary bidentate N-heterocyclic ligand to the extraction system. Two such ligands were studied, derivatives of bis-triazine and pyridine-triazine, which alone poorly extract the metal ions, but together with etBTBP they act as phase transfer reagents, improving the extraction kinetics to a different degree. The ability to transfer the metal ions from aqueous to organic phase depends on lipophilicity and acid/base properties of these auxiliary ligands, as well as on the mode of shaking the two liquid phases - gentle or vigorous. (orig.)

Lanthanide and actinide complexation studies with tetradentate 'N' donor ligands

International Nuclear Information System (INIS)

Bhattacharyya, A.; Mohapatra, M.; Mohapatra, P.K.; Rawat, N.; Tomar, B.S.; Gadly, T.; Ghosh, S.K.; Manna, D.; Ghanty, T.K.

2014-01-01

Because of their similar charge and chemical behaviour separation of trivalent actinides and lanthanides is an important and challenging task in nuclear fuel cycle. Soft (S,N) donor ligands show selectivity towards the trivalent actinides over the lanthanides. Out of various 'N' donor ligands studied, bis(1,2,4)triazinyl bipyridine (BTBP) and bis(1,2,4)triazinyl phenanthroline (BTPhen) were found to be most promising. In order to understand the separation behaviour of these ligands, their complexation studies with these 'f' block elements are essential. In the present work, complexation studies of various lanthanide ions (La 3+ , Eu 3+ and Er 3+ ) was studied with ethyl derivatives of BTBP (C 2 BTBP) and BTBPhen (C 2 BTPhen) and pentyl derivative of BTBP (C 5 BTBP) in acetonitrile medium using UV-Vis spectrophotometry, fluorescence spectroscopy and solution calorimetry. Computational studies were also carried out to understand the experimental results

Overview of the Main Achievements of the FP7 EURATOM Collaborative Project ACSEPT

International Nuclear Information System (INIS)

Bourg, Stephane

2013-01-01

Conclusion: • 4 consolidated flowsheets (r-SANEX, i-SANEX, 1c-SANEX, GANEX2); • 3 hots-tests, 1 spiked test (hydro); • A huge amount of work in organic synthesis and screening (hydro); • The best candidate ligand families considered as identified (hydro); • Relevant options for exhaustive electrolysis and actinide back-extraction from aluminum identified (pyro); • Relevant options for salt purification and waste conditioning (pyro); • Progresses in head-end steps; • Outputs for other FP7 projects; • High involvement in T&E issues; • High level of dissemination

The SACSESS hydrometallurgy domain - an overview

Energy Technology Data Exchange (ETDEWEB)

Geist, A. [Karlsruhe Institute of Technology - KIT, Institute for Nuclear Wsaste Disposal - INE, Karlsruhe (Germany); Taylor, R. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, CA20 1PG (United Kingdom); Ekberg, C. [Chalmers University of Technology, Nuclear Chemistry/Industrial Materials Recycling, SE-412 96 Goeteborg (Sweden); Guilbaud, P.; Bourg, S. [CEA, Centre de Marcoule, Nuclear Energy Division, F-30207 Bagnols-sur-Ceze (France); Modolo, G. [Forschungszentrum Juelich GmbH - FZJ, Institut fuer Energie- und Klimaforschung - IEK-6, Juelich (Germany)

2016-07-01

The EURATOM FP7 project SACSESS (Safety of Actinide Separation Processes) is in continuity of a long line of preceding EURATOM projects. SACSESS is organised along four domains, one of them related to the development of hydrometallurgical (i.e. solvent extraction based) actinide separations processes. Within this domain, the most promising processes developed in previous projects are further developed, improving their technology readiness level (TRL) towards the point at which safe industrial implementation will be achievable. The SACSESS reference compounds are: TODGA, CyMe{sub 4}-BTBP, SO{sub 3}-Ph-BTP, HEDTA and DTPA. TODGA is used to co-extract actinides and lanthanides from high-acidity raffinate solutions, separating from the non-lanthanide fission products. TODGA is also used to accelerate the extraction kinetics of CyMe{sub 4}-BTBP. CyMe{sub 4}-BTBP extracts actinides selectively over lanthanides and many other fission products. HEDTA and DTPA are used to strip actinides selectively over lanthanides from an organic phase containing both actinides and lanthanides. SO{sub 3}-Ph-BTP was developed to overcome some of the drawbacks of HEDTA and DTPA, such as the narrow pH window they are effective in.

Studies on the Interaction of a Novel 6,6''-bis(1,2,4-triazin-3-yl)- 2,2':6',2''-terpyridine Ligand with Lanthanide(III) Ions and Americium(III)

International Nuclear Information System (INIS)

Lewis, Frank W.; Harwood, Laurence M.; Hudson, Michael J.; Drew, Michael G.B.; Modolo, Giuseppe; Sypula, Michal; Desreux, Jean F.; Bouslimani, Nouri; Vidick, Geoffrey

2010-01-01

The new solvent extraction reagent 6,6''-bis(5,5,8,8-tetramethyl- 5,6,7,8-tetrahydro-1,2,4-benzo-triazin-3-yl)-2,2':6',2''-terpyridine (CyMe 4 -BTTP) has been synthesized in 4 steps from 2,2':6',2''-terpyridine. Detailed NMR and mass spectrometry studies indicate that the ligand forms 1:2 complexes with lanthanide(III) perchlorates where the aliphatic rings are conformationally constrained whereas 1:1 complexes are formed with lanthanide(III) nitrates where the aliphatic rings are conformationally mobile. An optimized structure of the 1:2 solution complex with Yb(III) was obtained from the relative magnitude of the induced paramagnetic shifts. X-ray crystallographic structures of the ligand and of its 1:1 complex with Y(III) were also obtained. In the absence of a phase-modifier, CyMe 4 -BTTP in 1-octanol showed a maximum distribution coefficient of Am(III) of 0.039 (±20%) and a maximum separation factor of Am(III) over Eu(III) of 12.0 from nitric acid solution. The metal(III) cations are extracted as the 1:1 complex from nitric acid solutions. The generally low distribution coefficients observed compared with the BTBPs arise because the 1:1 complex of CyMe 4 -BTTP is considerably less hydrophobic than the 1:2 complexes formed by the BTBPs. In M(BTTP) 3+ complexes, there is a competition between the nitrate ions and the ligand for the complexation of the metal. (authors)

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions.

Science.gov (United States)

Tunsu, Cristian; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-02-01

With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent's concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I2/KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5M I2/KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe4BTBP showed good removal of mercury, with an extraction efficiency of 97.5 ± 0.7% being achieved in a single stage. Better removal of mercury was achieved in a single stage using the extractants Cyanex 302 and Cyanex 923 in kerosene, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Partnew - New solvent extraction processes for minor actinides - final report

International Nuclear Information System (INIS)

Madic, C.; Testard, F.; Hudson, M.J.; Liljenzin, J.O.; Christiansen, B.; Ferrando, M.; Facchini, A.; Geist, A.; Modolo, G.; Gonzalez-Espartero, A.; Mendoza, J. de

2004-01-01

The objectives of the European project PARTNEW were to define solvent extraction processes for the partitioning of the minor actinides, Am and Cm, from the aqueous high active raffinate or high active concentrate issuing the reprocessing of nuclear spent fuels by the PUREX process. Eleven laboratories participated to the research: 1/ CEA-DEN (Marcoule), 2/ CEA-DSM (Saclay), 3/ UREAD (U.K.), 4/ CTU (Sweden), 5/ ITU (Germany), 6/ ENEA (Italy), 7/ PoliMi (Italy), 8/ FZK-INE (Germany), 9/ FZJ-ISR (Germany), 10/ CIEMAT (Spain) and 11/ UAM (Spain). The research was organised into eight work packages (WP): Basic and applied DIAMEX studies, using diamide extractants for the co-extraction of actinides(III) (An(III)) and lanthanides(III) (Ln(III)) nitrates (WP1 and WP2), Basic and applied SANEX studies based on the use of polydentate N-ligands for the An(III)/Ln(III) separation (WP3 and WP4), Basic and applied SANEX studies based on the use of synergistic mixtures made of bis-(chloro-phenyl)-di-thio-phosphinic acid + neutral O-bearing ligand, (WP5 and WP6), Basic SANEX studies for the An(III)/Ln(III) separation, based on the use of new S-bearing ligands, Basic and applied studies for the Am(III)/Cm(III) separation. The work done in the fundamental and applied domains was very fruitful. Several processes have been successfully tested with genuine high active raffinates and concentrate. (authors)

Partnew - New solvent extraction processes for minor actinides - final report; Partnew - Nouveaux procedes d'extraction par solvant pour les actinides mineurs - rapport final

Energy Technology Data Exchange (ETDEWEB)

Madic, C.; Testard, F.; Hudson, M.J.; Liljenzin, J.O.; Christiansen, B.; Ferrando, M.; Facchini, A.; Geist, A.; Modolo, G.; Gonzalez-Espartero, A.; Mendoza, J. de

2004-07-01

The objectives of the European project PARTNEW were to define solvent extraction processes for the partitioning of the minor actinides, Am and Cm, from the aqueous high active raffinate or high active concentrate issuing the reprocessing of nuclear spent fuels by the PUREX process. Eleven laboratories participated to the research: 1/ CEA-DEN (Marcoule), 2/ CEA-DSM (Saclay), 3/ UREAD (U.K.), 4/ CTU (Sweden), 5/ ITU (Germany), 6/ ENEA (Italy), 7/ PoliMi (Italy), 8/ FZK-INE (Germany), 9/ FZJ-ISR (Germany), 10/ CIEMAT (Spain) and 11/ UAM (Spain). The research was organised into eight work packages (WP): Basic and applied DIAMEX studies, using diamide extractants for the co-extraction of actinides(III) (An(III)) and lanthanides(III) (Ln(III)) nitrates (WP1 and WP2), Basic and applied SANEX studies based on the use of polydentate N-ligands for the An(III)/Ln(III) separation (WP3 and WP4), Basic and applied SANEX studies based on the use of synergistic mixtures made of bis-(chloro-phenyl)-di-thio-phosphinic acid + neutral O-bearing ligand, (WP5 and WP6), Basic SANEX studies for the An(III)/Ln(III) separation, based on the use of new S-bearing ligands, Basic and applied studies for the Am(III)/Cm(III) separation. The work done in the fundamental and applied domains was very fruitful. Several processes have been successfully tested with genuine high active raffinates and concentrate. (authors)

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions

International Nuclear Information System (INIS)

Tunsu, Cristian; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-01-01

Highlights: • A wet-based decontamination process for fluorescent lamp waste is proposed. • Mercury can be leached using iodine in potassium iodide solution. • The efficiency of the process increases with an increase in leachant concentration. • Selective leaching of mercury from rare earth elements is achieved. • Mercury is furthered recovered using ion exchange, reduction or solvent extraction. - Abstract: With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent’s concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I 2 /KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5 M I 2 /KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe 4 BTBP showed good removal of mercury, with an

Complexation of trivalent actinides and lanthanides with hydrophilic N-donor ligands for Am(III)/Cm(III) and An(III)/Ln(III) separation; Komplexierung von trivalenten Actiniden und Lanthaniden mit hydrophilen N-Donorliganden zur Am(III)/Cm(III)- bzw. An(III)/Ln(III)-Trennung

Energy Technology Data Exchange (ETDEWEB)

Wagner, Christoph

2017-07-24

The implementation of actinide recycling processes is considered in several countries, aiming at the reduction of long-term radiotoxicity and heat load of used nuclear fuel. This requires the separation of the actinides from the fission and corrosion products. The separation of the trivalent actinides (An(III)) Am(III) and Cm(III), however, is complicated by the presence of the chemically similar fission lanthanides (Ln(III)). Hydrophilic N-donor ligands are employed as An(III) or Am(III) selective complexing agents in solvent extraction to strip An(III) or Am(III) from an organic phase loaded with An(III) and Ln(III). Though they exhibit excellent selectivity, the complexation chemistry of these ligands and the complexes formed during solvent extraction are not sufficiently characterized. In the present thesis the complexation of An(III) and Ln(III) with hydrophilic N-donor ligands is studied by time resolved laser fluorescence spectroscopy (TRLFS), UV/Vis, vibronic sideband spectroscopy and solvent extraction. TRLFS studies on the complexation of Cm(III) and Eu(III) with the Am(III) selective complexing agent SO{sub 3}-Ph-BTBP (tetrasodium 3,3{sup '},3'',3{sup '''}-([2,2{sup '}-bipyridine]-6,6{sup '}-diylbis(1,2,4-triazine-3,5,6-triyl)) tetrabenzenesulfonate) revealed the formation of [M(SO{sub 3}-Ph-BTBP){sub n}]{sup (4n-3)-} complexes (M = Cm(III), Eu(III); n = 1, 2). The conditional stability constants were determined in different media yielding two orders of magnitude larger β{sub 2}-values for the Cm(III) complexes, independently from the applied medium. A strong impact of ionic strength on the stability and stoichiometry of the formed complexes was identified, resulting from the stabilization of the pentaanionic [M(SO{sub 3}-Ph-BTBP){sub 2}]{sup 5-} complex with increasing ionic strength. Thermodynamic studies of Cm(III)-SO{sub 3}-Ph-BTBP complexation showed that the proton concentration of the applied medium impacts

Begoniaceae

NARCIS (Netherlands)

Stoffers, A.L.

1966-01-01

Herbs or undershrubs, somewhat succulent or woody near the base, often provided with tubers. Leaves alternate, usually unequal-sided, entire, lobed or digitately parted. Stipules caducous or deciduous. Inflorescence consisting of unisexual or bisexual, axillary cymes. Male flowers: sepals 2; petals

Chiritopsis longzhouensis, a New Species of Gesneriaceae from Limestone Areas in Guangxi, China

Directory of Open Access Journals (Sweden)

Bo Pan

2010-11-01

Full Text Available A new species of Gesneriaceae, Chiritopsis longzhouensis B. Pan & W. H. Wu from limestone areas in Guangxi, China, is described and illustrated. The new species is similar to C. jingxiensis Yan Liu, W. B. Xu & H. S. Gao in the corolla shape, but differs in its leaf blade 2-4 × 1.3-2.5 cm, appressed pilose on both surfaces, Cymes 5-10, 1-3-branched, each 5-25-flowered, filaments geniculate about 1 mm above base, sparsely glandular-puberulent, staminodes 3.

Slides with no attached paper

International Nuclear Information System (INIS)

Warin, Dominique; Wallenius, Janne; Ouzounian, Gerald; Wikberg, Peter; Todd, Terry A.; Kormilitsyn, Mikhael V.; Osipenko, Alexander G.; Mayorshin, A.A.; McLachlan, Fiona; Nash, Ken L.; Nilsson, M.; Grimes, T.; Braley, J.C.; TAKESHITA, Kenji; Babain, Vasiliy A.; Spendlikova, I.; Distler, P.; John, J.; Sebesta, F.; VU, Trong-Hung; SIMONIN, Jean-Pierre; PAULENOVA, Alena; PRECEK, Martin; HARTIG, Kyle; KNAPP, Nathan; Vidick, Geoffrey; Bouslimani, Nouri; Desreux, Jean F.; Lewis, F.W.; Hudson, M.J.; Harwood, L.M.; Nunez, Ana; Nagarajan, K.; Vasudeva Rao, P.R.; Raj, Baldev; Ignatiev, Victor; Surenkov, Alexander; Pouchon, Manuel A.; Skarnemark, Gunnar; Allard, Stefan; Ekberg, Christian; Retegan, Teodora; Nordlund, Anders; John, Jan; Maershin, Alexander; Zakirov, R.; Panov, A.; Toropov, Andrey

2010-01-01

This document brings together the different presentations (slides) given at the workshop but with no attached paper. These slides refer to the following presentations: - Presentation of ITN (Instituto Tecnologico e Nuclear); - Minor Actinide Partitioning (Dominique Warin); - Transmutation (Janne Wallenius); - Radioactive Waste Management, IGD-TP (Gerald Ouzounian); - Present status of the Swedish nuclear waste management programme (Peter Wikberg); - The U.S. Fuel Cycle Research and Development Program - Separations Research and Development (Terry Todd); - Strategies and national programs of closed fuel cycles - Russian Expert Vision (Mikhael Kormilitsyn) - Extraction Studies Of Potential Solvent Formulations For The GANEX Process (Fiona MacLachlan); - Investigations of The Fundamental Chemistry of the TALSPEAK Process (Ken Nash); - Extraction Separation of Trivalent Minor Actinides and Lanthanides by Hexa-dentate Nitrogen-donor Extractant, TPEN, and its Analogs (Kenji Takeshita); - Fluorinated Diluents for HLW Processing - technological point of view (Vasiliy Babain); - Extraction properties of some new pyridine molecules and search for better diluents (Irena Spendlikova); - Kinetics of extraction of Eu 3+ ion by TODGA and CyMe 4 -BTBP studied using the RMC technique (Trong Hung Vu); - Redox Chemistry of Neptunium in Solutions of Nitric Acid (Alena Paulenova); - NMR applied to actinide ions and their complexes. In search of covalency effects (Geoffrey Vidick); - Towards 'Stability Rules' for Radiolysis of bis-DGA compounds (Ana Nunez); - Pyroprocess Research Activities at IGCAR, Kalpakkam, India (K. Nagarajan); - Critical issues of nuclear energy systems employing molten salt fluorides: from ISTC No. 1606 to No. 3749 (1. year of project activity) and MARS/EVOL cooperation (Victor Ignatiev); - Conversion processes: Internal Gelation and the Sphere-pac concept (Manuel Pouchon); - A Combined Nuclear Technology and Nuclear Chemistry Master. A Unique

Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

Energy Technology Data Exchange (ETDEWEB)

Distler, P.; Spendlikova, I. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; John, J. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; Czech Technical Univ., Prague (Czech Republic). Centre for Radiochemistry and Radiation Chemistry; Harwood, L.M.; Hudson, M.J.; Lewis, F.W. [Reading Univ., Berkshire (United Kingdom). Dept. of Chemistry

2012-07-01

Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe{sub 4}-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO{sub 3}, 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO{sub 3}, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, D{sub Am} and SF{sub Am/Eu} decreased in the order of alkyl substitution 2 > 4 {proportional_to} 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

A ''master key'' to chemical separation processes

International Nuclear Information System (INIS)

Madic, Ch.; Hill, C.

2002-01-01

One of the keys to sorting nuclear waste is extracting minor actinides - the most troublesome long-lived elements - from the flow of waste by separating them from lanthanides, which have very similar chemical properties to actinides, for possible transmutation into shorter-lived elements. Thanks to a European initiative coordinated by CEA, this key is now available: its name is Sanex. There now remains to develop tough, straightforward industrial processes to integrate it into a new nuclear waste management approach by 2005. Sanex joins the Diamex process, used for the combined separation of lanthanides and minor actinides from fission products. A third process, Sesame, designed to separate americium, completes the list of available separation processes. (authors)

Mass spectrometric studies of the complexing behaviour of actinide ions in solution

International Nuclear Information System (INIS)

Steppert, Michael

2012-01-01

As the long-term radiotoxicity of spent nuclear fuel is governed by Plutonium and the Minor Actinides, these elements are focussed on for investigations in the framework of safety assessment for nuclear waste repositories. To shed more light on the selectivity of the partitioning ligands BTP and BTBP towards the extraction of trivalent actinides, the complexes these ligands form with lanthanides in octanolic solution were characterized. The differences in the extraction efficiencies among the different lanthanides were traced back to the varying preferential formation of Ln(BTP)3 complexes, depending on the ionic radius of the lanthanides. Additionally it was shown that depending on the sterical demand of BTBP ligands nitrate anions coordinate in the first coordination shell of Eu(BTBP)2-complexes. As the behavior of Plutonium under geochemical conditions is of particular interest for the safety assessment of potential nuclear waste repositories, the second part of the thesis focuses on the hydrolysis and colloid formation behavior of aqueous Plutonium solutions. The solution species of Zirconium(IV) as analogue for Plutonium(IV) as well as of Uranium(VI) and Plutonium(VI) were characterized and quantified by means of electrospray ionization mass spectrometry. Moreover the colloid-induced reduction of Pu(V) to Pu(IV) and the subsequent formation of colloidal species was investigated. [de

Celastraceae

NARCIS (Netherlands)

Stoffers, A.L.

1984-01-01

Trees or shrubs, sometimes climbing or twining. Leaves alternate or opposite, simple, deciduous or persistent. Stipules small and caducous or wanting. Inflorescence generally consisting of axillary cymes; pedicels commonly jointed. Flowers hermaphrodite or functionally unisexual, actinomorphous.

Oleaceae

NARCIS (Netherlands)

Stoffers, A.L.

1982-01-01

Evergreen or deciduous trees or shrubs or sometimes woody vines. Leaves opposite, verticillate or very rarely alternate, simple or pinnately compound. Stipules wanting. Inflorescence consisting of mostly terminal dichasial panicles or cymes. Bracts and braoteoles present. Flowers hermaphrodite or

Portulacaceae

NARCIS (Netherlands)

Stoffers, A.L.

1980-01-01

Herbs or shrubby plants, often somewhat succulent. Leaves opposite, alternate or in basal rosettes. Stipules scarious or modified into hairs or rarely wanting. Flowers actinomorphic, perfect, solitary or crowded at the apex of the stems and branches or in terminal or axillary racemes or cymes.

Fission product interactions with nitrogen donor ligands used for spent nuclear fuel treatment

Czech Academy of Sciences Publication Activity Database

Aneheim, E.; Grüner, Bohumír; Ekberg, C.; Foreman, M.R.S.J.; Hájková, Zuzana; Löfström-Engdahl, E.; Drew, M. G. B.; Hudson, M.J.

2013-01-01

Roč. 50, č. 1 (2013), s. 154-163 ISSN 0277-5387 R&D Projects: GA MŠk(CZ) 7G08073 Grant - others:ACSEPT(XE) FP7-CP-2007-211 267 Institutional support: RVO:61388980 Keywords : BTBP * palladium * complexation * water solubility Subject RIV: CA - Inorganic Chemistry Impact factor: 2.047, year: 2013

Partitioning of minor actinides: research at Juelich and Karlsruhe Research Centres

International Nuclear Information System (INIS)

Geist, A.; Weigl, M.; Gompper, K.; Modolo, G.

2007-01-01

Full text of publication follows. The work on minor actinide (MA) partitioning carried out at Karlsruhe and Juelich is integrated in the EC FP6 programme, EUROPART. Studies include the DIAMEX process (co-extraction of MA and lanthanides from PUREX raffinate) and the SANEX process (separation of MA from lanthanides). Aspects ranging from developing and improving highly selective and efficient extraction reagents, to fundamental structural studies, to process development and testing are covered. SANEX is a challenge in separation chemistry because of the chemical similarity of trivalent actinides and lanthanides. The extracting agents 2,6-di(5,6-di-propyl-1,2,4-triazine-3-yl)pyridine (n-Pr-BTP), developed at Karlsruhe, and the synergetic mixture of di(chloro-phenyl)di-thio-phosphinic acid (R2PSSH) with tri-n-octyl-phosphine oxide (TOPO), developed at Juelich, are considered a breakthrough because of their high separation efficiency in acidic systems. Separation factors for americium over lanthanides of more than 30 (R2PSSH+TOPO) and 130 (n-Pr-BTP) are achieved. To gain understanding of these selectivities, comparative investigations on the structures of curium and europium complexed with these SANEX ligands were performed at Karlsruhe. Extended X-ray absorption fine structure (EXAFS) analysis revealed distinct structural differences between curium and europium complexed with R2PSSH + TOPO, though no such differences were found for n-Pr-BTP. These investigations were therefore complemented by time-resolved laser fluorescence spectroscopic investigations (TRLFS), showing complex stabilities and speciation to differ between n-Pr-BTP complexes of curium and europium. Kinetics of mass transfer was studied for both R2PSSH+TOPO and n-Pr-BTP systems. For the R2PSSH + TOPO system, diffusion was identified to control extraction rates. For the n-Pr-BTP system, a slow chemical reaction was identified as the rate-controlling process. These results were implemented into computer

A new bioactive ursane-type triterpenoid from Croton ...

Indian Academy of Sciences (India)

blance of the leaves and flower cymes to that of Tulsi, this plant is often called Ban Tulsi locally. C. bon- plandianum was reported to have many medicinal uses including the repellent property against the insects,2–5 mosquito, A. aegypti.6 Local people in the remote area of West Bengal, India are using its root against snake.

U_xTh_1_-_x(C_2O_4)_2 solide characterisation studies

International Nuclear Information System (INIS)

Carrigan, C.; Taylor, R.; Sarsfield, M.

2016-01-01

Many advanced reprocessing schemes under development are aimed at co-processing and co-conversion of actinides, unlike current reprocessing plants that produce separate uranium and plutonium products. The most well developed option for the co-conversion stage is probably oxalate co-precipitation, followed by the thermal co-conversion to a mixed oxide product. It is thus envisaged that future processes will avoid separation of plutonium from uranium and instead allow part of the uranium to flow with the plutonium, resulting in co-precipitation as the oxalate, and finally co-conversion to a mixed uranium-plutonium oxide (MOX), which can be fabricated into recycled nuclear fuel for further energy generation. The co-crystallisation of uranium (IV) and plutonium (III) into a single oxalate structure ensures the homogenous distribution of the 2 actinides at the molecular scale. The joint conversion of uranium and plutonium to the oxide form makes it possible to remove the complicated step of blending and grinding the 2 distinct oxide powders, as currently employed for the purposes of MOX fuel fabrication. This concept can also be extended to other actinides, including minor actinides from partitioning processes such as SANEX (Selective Actinide Extraction) and GANEX (Grouped Actinide Extraction) processes or even a thorium containing product from recycle of thorium based fuels. A selection of U_xTh_1_-_x(C_2O_4)_2 solids at varying concentrations of uranium and thorium were prepared by oxalate co-precipitation. Uranium (VI) was conditioned electrochemically at -0.7 V to uranium (IV), in the presence of hydrazine. The reduced uranium (IV) in nitric acid was mixed with thorium nitrate solutions at different concentration ratios with oxalic acid. The mixed tetravalent uranium-thorium oxalate solid products have been characterised by Raman and IR spectroscopies. The influence of thorium substituted into the uranium oxalate structure was evaluated. Several vibrational modes

Inflorescence development in petunia: through the maze of botanical terminology.

Science.gov (United States)

Castel, Rob; Kusters, Elske; Koes, Ronald

2010-05-01

Flowering plants have developed many ways to arrange their flowers. A flower-bearing branch or system of branches is called an inflorescence. The number of flowers that an inflorescence contains ranges from a single flower to endless flower-clusters. Over the past centuries, botanists have classified inflorescences based on their morphology, which has led to an unfortunate maze of complex botanical terminology. With the rise of molecular developmental biology, research has become increasingly focused on how inflorescences develop, rather than on their morphology. It is the decisions taken by groups of stem cells at the growing tips of shoots, called meristems, on when and where to produce a flower or a shoot that specify the course of inflorescence development. Modelling is a helpful aid to follow the consequences of these decisions for inflorescence development. The so-called transient model can produce the broad inflorescence types: cyme, raceme, and panicle, into which most inflorescences found in nature can be classified. The analysis of several inflorescence branching mutants has led to a solid understanding of cymose inflorescence development in petunia (Petunia hybrida). The cyme of petunia is a distinct body plan compared with the well-studied racemes of Arabidopsis and Antirrhinum, which provides an excellent opportunity to study evolutionary developmental biology (evo-devo) related questions. However, thus far, limited use has been made of this opportunity, which may, at least in part, be due to researchers getting lost in the terminology. Some general issues are discussed here, while focusing on inflorescence development in petunia.

Rapid selective separation of americium/curium from simulated nuclear forensic matrices using triazine ligands

Energy Technology Data Exchange (ETDEWEB)

Higginson, Matthew A.; Livens, Francis R.; Heath, Sarah L. [Manchester Univ. (United Kingdom). Centre for Radiochemistry Research; Thompson, Paul; Marsden, Olivia J. [AWE, Aldermaston, Reading (United Kingdom); Harwood, Laurence M.; Hudson, Michael J. [Reading Univ. (United Kingdom). Dept. of Chemistry; Lewis, Frank W. [Reading Univ. (United Kingdom). Dept. of Chemistry; Northumbria Univ., Newcastle upon Tyne (United Kingdom). Dept. of Chemical and Forensic Sciences

2015-07-01

In analysis of complex nuclear forensic samples containing lanthanides, actinides and matrix elements, rapid selective extraction of Am/Cm for quantification is challenging, in particular due the difficult separation of Am/Cm from lanthanides. Here we present a separation process for Am/Cm(III) which is achieved using a combination of AG1-X8 chromatography followed by Am/Cm extraction with a triazine ligand. The ligands tested in our process were CyMe{sub 4}-BTPhen, CyMe{sub 4}-BTBP, CA-BTP and CA-BTPhen. Our process allows for purification and quantification of Am and Cm (recoveries 80% - 100%) and other major actinides in < 2 d without the use of multiple columns or thiocyanate. The process is unaffected by high level Ca(II)/Fe(III)/Al(III) (10 mg mL{sup -1}) and thus requires little pre-treatment of samples.

Estudo do comportamento ácido-base da 4,4'-ditiodipiridina The acid-base properties of 4,4'-dithiodipyridine

Directory of Open Access Journals (Sweden)

Ícaro de Sousa Moreira

1998-10-01

Full Text Available Despite the importance of the 4,4'-dithiodipyridine as an electrode modifier on the protein electrochemical studies and as a remarkable bridged-ligand on conducting electronic density in binuclear mixed valence complexes, there is no data available in the literature concerning acid-base behavior of this compound. Aiming to afford such information we undertook the ionization equilibrium study of this ligand. Although two acid species, DTDPH+ and DTDPH2+ have been detected in solution, only the diacid-form was possible to be isolated as a perclorate salt DTDPH2(ClO42. The ionization constants for the two step equilibrium processes (pKa1=2.70 and pKa2=4.80 were determined by using the spectrophotometric technique and aqueous solutions of CF3COONa, mu=0,1 mol.L-1 .

A micro hot test of the Chalmers-GANEX extraction system on used nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Bauhn, L.; Hedberg, M.; Aneheim, E.; Ekberg, C.; Loefstroem-Engdahl, E.; Skarnemark, G. [Department of Chemical and Biological Engineering, Nuclear Chemistry, Chalmers University of Technology, Kemivaegen 4, SE-412 96 Goeteborg (Sweden)

2013-07-01

In the present study, a 'micro hot test' has been performed using the Chalmers-GANEX (Group Actinide Extraction) system for partitioning of used nuclear fuel. The test included a pre-extraction step using N,N-di-2- ethylhexyl-butyramide (DEHBA) in n-octanol to remove the bulk part of the uranium. This pre-extraction was followed by a group extraction of actinides using the mixture of TBP and CyMe{sub 4}-BTBP in cyclohexanone as suggested in the Chalmers-GANEX process, and a three stage stripping of the extracted actinides. Distribution ratios for the extractions and stripping were determined based on a combination of γ- and α-spectrometry, as well as ICP-MS measurements. Successful extraction of uranium, plutonium and the minor actinides neptunium, americium and curium was achieved. However, measurements also indicated that co-extraction of europium occurs to some extent during the separation. These results were expected based on previous experiments using trace concentrations of actinides and lanthanides. Since this test was only performed in one stage with respect to the group actinide extraction, it is expected that multi stage tests will give even better results. (authors)

Dog Mathematics: Exploring Base-4

Science.gov (United States)

Kurz, Terri L.; Yanik, H. Bahadir; Lee, Mi Yeon

2016-01-01

Using a dog's paw as a basis for numerical representation, sixth grade students explored how to count and regroup using the dog's four digital pads. Teachers can connect these base-4 explorations to the conceptual meaning of place value and regrouping using base-10.

U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2} solide characterisation studies

Energy Technology Data Exchange (ETDEWEB)

Carrigan, C.; Taylor, R.; Sarsfield, M. [National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom)

2016-07-01

Many advanced reprocessing schemes under development are aimed at co-processing and co-conversion of actinides, unlike current reprocessing plants that produce separate uranium and plutonium products. The most well developed option for the co-conversion stage is probably oxalate co-precipitation, followed by the thermal co-conversion to a mixed oxide product. It is thus envisaged that future processes will avoid separation of plutonium from uranium and instead allow part of the uranium to flow with the plutonium, resulting in co-precipitation as the oxalate, and finally co-conversion to a mixed uranium-plutonium oxide (MOX), which can be fabricated into recycled nuclear fuel for further energy generation. The co-crystallisation of uranium (IV) and plutonium (III) into a single oxalate structure ensures the homogenous distribution of the 2 actinides at the molecular scale. The joint conversion of uranium and plutonium to the oxide form makes it possible to remove the complicated step of blending and grinding the 2 distinct oxide powders, as currently employed for the purposes of MOX fuel fabrication. This concept can also be extended to other actinides, including minor actinides from partitioning processes such as SANEX (Selective Actinide Extraction) and GANEX (Grouped Actinide Extraction) processes or even a thorium containing product from recycle of thorium based fuels. A selection of U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2} solids at varying concentrations of uranium and thorium were prepared by oxalate co-precipitation. Uranium (VI) was conditioned electrochemically at -0.7 V to uranium (IV), in the presence of hydrazine. The reduced uranium (IV) in nitric acid was mixed with thorium nitrate solutions at different concentration ratios with oxalic acid. The mixed tetravalent uranium-thorium oxalate solid products have been characterised by Raman and IR spectroscopies. The influence of thorium substituted into the uranium oxalate structure was evaluated

Hydrometallurgical minor actinide separation in hollow fiber modules

International Nuclear Information System (INIS)

Geist, A.; Weigl, M.; Gompper, K.

2004-01-01

Hollow fiber modules (HFM) were used as phase contacting devices for hydrometallurgical minor actinide separation in the Partitioning and Transmutation context. Two single-HFM setups, one using commercially available HFM, the other one using miniature HFM, have been developed and manufactured. Several very successful DIAMEX and SANEX once-through tests were performed. The major advantage of the new miniature HFM is their size drastically reducing chemicals consumption: only several 10 mL of feed phases are required for a test. (authors)

2-Aminopyridine-Based Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Inhibitors: Assessment of Mechanism-Based Safety.

Science.gov (United States)

Dow, Robert L; Ammirati, Mark; Bagley, Scott W; Bhattacharya, Samit K; Buckbinder, Leonard; Cortes, Christian; El-Kattan, Ayman F; Ford, Kristen; Freeman, Gary B; Guimarães, Cristiano R W; Liu, Shenping; Niosi, Mark; Skoura, Athanasia; Tess, David

2018-04-12

Studies have linked the serine-threonine kinase MAP4K4 to the regulation of a number of biological processes and/or diseases, including diabetes, cancer, inflammation, and angiogenesis. With a majority of the members of our lead series (e.g., 1) suffering from time-dependent inhibition (TDI) of CYP3A4, we sought design avenues that would eliminate this risk. One such approach arose from the observation that carboxylic acid-based intermediates employed in our discovery efforts retained high MAP4K4 inhibitory potency and were devoid of the TDI risk. The medicinal chemistry effort that led to the discovery of this central nervous system-impaired inhibitor together with its preclinical safety profile is described.

Overview of the Main Achievements of the FP7 EURATOM Collaborative Project ACSEPT

International Nuclear Information System (INIS)

Bourg, S.; Geist, A.; Cassayre, L.; Rhodes, C.; Ekberg, C.

2015-01-01

Nuclear power plays a key role in limiting European Union’s greenhouse gases emissions, and makes an important contribution to improve EU’s independence, security and diversity of energy supply. However, its social acceptance is closely linked to an enhanced safety in the management of long-lived radioactive waste contributing to resource efficiency and cost-effectiveness of this energy and ensuring a robust and socially acceptable system of protection of man and environment. Among the different strategies, partitioning and transmutation (P&T) allows a reduction of the amount, the radiotoxicity and the thermal power of these wastes, leading to an optimal use of geological repository sites. ACSEPT successfully addressed the partitioning issues by focusing on the development of advanced separation processes, both aqueous and pyrochemical. Head-end steps, fuel refabrication, solvent treatment, waste management were also taken into account. In aqueous process development, the SANEX, innovative SANEX and GANEX flowsheets were designed and tested in hot cells. In pyrometallurgy, studies on actinide back-extraction from aluminium and exhaustive electrolysis allowed the validation of two flowsheets developed from more then 10 years in Europe. A training and education program including seminars, workshops, brainstorming meeting but also student exchanges and support to post-doctorate fellowships was a key point for maintaining and increasing a high expertise level in actinide separation sciences in Europe. Six month after the end of ACSEPT, and when its follow-up, SACSESS, just begins, it is time to highlight its main achievements. (author)

Molecular and supramolecular speciations of solvent extraction systems based on malonamide and/or dialkyl-phosphoric acids for An(III)/Ln(III); Speciations moleculaire et supramoleculaire de systemes d'extraction liquide-liquide a base de malonamide et/ou d'acides dialkylphosphoriques pour la separation An(III)/Ln(III)

Energy Technology Data Exchange (ETDEWEB)

Gannaz, B

2006-06-15

The solvent extraction system used in the DIAMEX-SANEX process, developed for the actinide(III)/lanthanide(III) separation, is based on the use of mixtures of the malonamide DMDOHEMA and a dialkyl-phosphoric acid (HDEHP or HDHP), in hydrogenated tetra-propylene. The complexity of these systems urges on a novel approach to improve the conventional methods (thermodynamics, solvent extraction) which hardly explain the macroscopic behaviors observed (3. phase, over-stoichiometry). This approach combines studies on both supramolecular (VPO, SANS, SAXS) and molecular (liquid-liquid extraction, ESI-MS, IR, EXAFS) speciations of single extractant systems (DMDOHEMA or HDHP in in n-dodecane) and their mixture. In spite of safety constraints due to the handling of radio-material, they were used in the studies as much as possible, like for SAXS measurements on americium-containing samples, a worldwide first-time. In each of the investigated systems, actinides(III) and lanthanides(III) are extracted to the organic phase in polar cores of reversed micelles, the inner and outer-sphere compositions of which are proposed. Thus, the 4f and 5f cations are extracted by reversed micelles such as [(DMDOHEMA){sub 2}M(NO{sub 3}){sub 3}]{sub inn} (DMDOHEMA){sub x}(HNO{sub 3}){sub z}(H{sub 2}O){sub w}]{sub out} and M(DHP){sub 3}(HDHP){sub y-3}(H{sub 2}O){sub w} with y = 3 to 6, for the single extractant systems. In the case of the two extractants system, the less concentrated one acts like a co-surfactant regarding the mixed aggregate formation [(DMDOHEMA){sub 2}M(NO{sub 3}){sub 3-v}(DHP){sub v}]{sub inn} [(DMDOFIEMA){sub x}(HDHP){sub y}(HNO{sub 3})z(H{sub 2}O){sub w}]{sub out}. (author)

A spatiotemporal-based scheme for efficient registration-based segmentation of thoracic 4-D MRI.

Science.gov (United States)

Yang, Y; Van Reeth, E; Poh, C L; Tan, C H; Tham, I W K

2014-05-01

Dynamic three-dimensional (3-D) (four-dimensional, 4-D) magnetic resonance (MR) imaging is gaining importance in the study of pulmonary motion for respiratory diseases and pulmonary tumor motion for radiotherapy. To perform quantitative analysis using 4-D MR images, segmentation of anatomical structures such as the lung and pulmonary tumor is required. Manual segmentation of entire thoracic 4-D MRI data that typically contains many 3-D volumes acquired over several breathing cycles is extremely tedious, time consuming, and suffers high user variability. This requires the development of new automated segmentation schemes for 4-D MRI data segmentation. Registration-based segmentation technique that uses automatic registration methods for segmentation has been shown to be an accurate method to segment structures for 4-D data series. However, directly applying registration-based segmentation to segment 4-D MRI series lacks efficiency. Here we propose an automated 4-D registration-based segmentation scheme that is based on spatiotemporal information for the segmentation of thoracic 4-D MR lung images. The proposed scheme saved up to 95% of computation amount while achieving comparable accurate segmentations compared to directly applying registration-based segmentation to 4-D dataset. The scheme facilitates rapid 3-D/4-D visualization of the lung and tumor motion and potentially the tracking of tumor during radiation delivery.

48 CFR 915.404-4-71-6 - Fee base.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Fee base. 915.404-4-71-6... CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 915.404-4-71-6 Fee base. (a) The fee base shown... estimate of cost to which a percentage factor is applied to determine maximum fee allowances. The fee base...

New strategies in actinide separation - water-soluble complexing agents for the innovative SANEX process

International Nuclear Information System (INIS)

Ruff, Christian M.; Muelllich, Udo; Geist, Andreas; Panak, Petra J.

2012-01-01

Reduction of the radiotoxicity and thermal output of radioactive wastes prior to their permanent disposal is a topic of extreme interest for the issue of final nuclear waste disposal. One possibility to this end is a process referred to as actinide separation. This process can be optimised by means of a newly developed water-soluble molecule, as has been shown in studies on the molecule's complex chemistry using ultra-modern laser-based spectroscopy methods under process-relevant reaction conditions. Through the use of curium (III) and europium (III), which as members of the trivalent actinides and lanthanides family have excellent spectroscopic properties, it has been possible to generate spectroscopic and thermodynamic data which will facilitate our understanding of the complex chemistry and extraction chemistry of this molecule family.

Regulation of microtubule-based transport by MAP4

Science.gov (United States)

Semenova, Irina; Ikeda, Kazuho; Resaul, Karim; Kraikivski, Pavel; Aguiar, Mike; Gygi, Steven; Zaliapin, Ilya; Cowan, Ann; Rodionov, Vladimir

2014-01-01

Microtubule (MT)-based transport of organelles driven by the opposing MT motors kinesins and dynein is tightly regulated in cells, but the underlying molecular mechanisms remain largely unknown. Here we tested the regulation of MT transport by the ubiquitous protein MAP4 using Xenopus melanophores as an experimental system. In these cells, pigment granules (melanosomes) move along MTs to the cell center (aggregation) or to the periphery (dispersion) by means of cytoplasmic dynein and kinesin-2, respectively. We found that aggregation signals induced phosphorylation of threonine residues in the MT-binding domain of the Xenopus MAP4 (XMAP4), thus decreasing binding of this protein to MTs. Overexpression of XMAP4 inhibited pigment aggregation by shortening dynein-dependent MT runs of melanosomes, whereas removal of XMAP4 from MTs reduced the length of kinesin-2–dependent runs and suppressed pigment dispersion. We hypothesize that binding of XMAP4 to MTs negatively regulates dynein-dependent movement of melanosomes and positively regulates kinesin-2–based movement. Phosphorylation during pigment aggregation reduces binding of XMAP4 to MTs, thus increasing dynein-dependent and decreasing kinesin-2–dependent motility of melanosomes, which stimulates their accumulation in the cell center, whereas dephosphorylation of XMAP4 during dispersion has an opposite effect. PMID:25143402

Aquaporin-4 autoantibodies in neuromyelitis optica spectrum disorders: comparison between tissue-based and cell-based indirect immunofluorescence assays

Directory of Open Access Journals (Sweden)

Chan Koon H

2010-09-01

Full Text Available Abstract Background Neuromyelitis optica spectrum disorders (NMOSD are severe central nervous system inflammatory demyelinating disorders (CNS IDD characterized by monophasic or relapsing, longitudinally extensive transverse myelitis (LETM and/or optic neuritis (ON. A significant proportion of NMOSD patients are seropositive for aquaporin-4 (AQP4 autoantibodies. We compared the AQP4 autoantibody detection rates of tissue-based indirect immunofluorescence assay (IIFA and cell-based IIFA. Methods Serum of Chinese CNS IDD patients were assayed for AQP4 autoantibodies by tissue-based IIFA using monkey cerebellum and cell-based IIFA using transfected HEK293 cells which express human AQP4 on their cell membranes. Results In total, 128 CNS IDD patients were studied. We found that 78% of NMO patients were seropositive for AQP4 autoantibodies by cell-based IIFA versus 61% by tissue-based IFA (p = 0.250, 75% of patients having relapsing myelitis (RM with LETM were seropositive by cell-based IIFA versus 50% by tissue-based IIFA (p = 0.250, and 33% of relapsing ON patients were seropositive by cell-based IIFA versus 22% by tissue-based IIFA (p = 1.000; however the differences were not statistically significant. All patients seropositive by tissue-based IIFA were also seropositive for AQP4 autoantibodies by cell-based IIFA. Among 29 NMOSD patients seropositive for AQP4 autoantibodies by cell-based IIFA, 20 (69% were seropositive by tissue-based IIFA. The 9 patients seropositive by cell-based IIFA while seronegative by tissue-based IIFA had NMO (3, RM with LETM (3, a single attack of LETM (1, relapsing ON (1 and a single ON attack (1. Among 23 NMO or RM patients seropositive for AQP4 autoantibodies by cell-based IIFA, comparison between those seropositive (n = 17 and seronegative (n = 6 by tissue-based IIFA revealed no differences in clinical and neuroradiological characteristics between the two groups. Conclusion Cell-based IIFA is slightly more sensitive

N4H9Cu7S4: a hydrazinium-based salt with a layered Cu7S4- framework.

Science.gov (United States)

Mitzi, David B

2007-02-05

Crystals of a hydrazinium-based copper(I) sulfide salt, N4H9Cu7S4 (1), have been isolated by an ambient temperature solution-based process. In contrast to previously reported hydrazinium salts of main-group metal chalcogenides, which consist of isolated metal chalcogenide anions, and ACu7S4 (A = NH4+, Rb+, Tl+, K+), which contains a more three-dimensional Cu7S4- framework with partial Cu-site occupancy, the structure of 1 [P21, a = 6.8621(4) A, b = 7.9851(4) A, c = 10.0983(5) A, beta = 99.360(1) degrees , Z = 2] is composed of extended two-dimensional Cu7S4- slabs with full Cu-site occupancy. The Cu7S4- slabs are separated by a mixture of hydrazinium and hydrazine moieties. Thermal decomposition of 1 into copper(I) sulfide proceeds at a significantly lower temperature than that observed for analogous hydrazinium salts of previously considered metal chalcogenides, completing the transition at temperatures as low as 120 degrees C. Solutions of 1 may be used in the solution deposition of a range of Cu-containing chalcogenide films.

Modification of JRR-4 based on safety evaluation

Energy Technology Data Exchange (ETDEWEB)

Izumo, Hironobu; Nakajima, Teruo; Funayama, Yoshiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

Since the first criticality was achieved on January 28, 1965, JRR-4 has been operated safely until on January 12, 1996. The modification of JRR-4 was planned according to the framework of reduced enrichment on research reactor program. The modification was designed based on the several national safety guides. JRR-4 has some modifications of facilities to satisfy the guides and guides criteria. (author)

A review on g-C3N4-based photocatalysts

International Nuclear Information System (INIS)

Wen, Jiuqing; Xie, Jun; Chen, Xiaobo; Li, Xin

2017-01-01

Graphical abstract: The photocatalytic fundamentals, versatile properties, design strategies and potential applications of g-C 3 N 4 -based photocatalysts were systematically summarized and addressed. - Highlights: • The photocatalytic fundamentals of g-C 3 N 4 were systematically summarized. • The versatile properties of g-C 3 N 4 photocatalysts were highlighted. • The different design strategies of g-C 3 N 4 photocatalysts were reviewed. • The important photocatalytic applications of g-C 3 N 4 were also addressed. - Abstract: As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C 3 N 4 -based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C 3 N 4 -based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C 3 N 4 -based photocatalysts. The versatile properties of g-C 3 N 4 -based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H 2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction, selective organic

Poly(3,4-ethylenedioxythiophene)-based glucose biosensors

NARCIS (Netherlands)

Kros, A.; Hövell, W.F.M. van; Sommerdijk, N.A.J.M.; Nolte, R.J.M.

2001-01-01

Amperometric biosensors for the recognition of glucose oxidase (GOx) based on poly(3,4-ethylenedioxythiophene) (PEDOT) were fabricated for the first time. The resulting biosensor has potential applications for long-term glucose measurements.

(3-Aminopropyl)-4-methylpiperazine End-capped Poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based Multilayer Films for Gene Delivery

Science.gov (United States)

Li, Cuicui; Tzeng, Stephany Y; Tellier, Liane E.; Green, Jordan J

2013-01-01

Biodegradable polyelectrolyte surfaces for gene delivery were created through electrospinning of biodegradable polycations combined with iterative solution-based multilayer coating. Poly(β-amino ester) (PBAE) poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) end-capped with 1-(3-aminopropyl)-4-methylpiperazine was utilized due to its ability to electrostatically interact with anionic molecules like DNA, its biodegradability, and its low cytotoxicity. A new DNA release system was developed for sustained release of DNA over 24 hours, accompanied by high exogenous gene expression in primary human glioblastoma (GB) cells. Electrospinning a different PBAE, poly(1,4-butanediol diacrylate-co-4,4′-trimethylenedipiperidine), and its combination with polyelectrolyte 1-(3-aminopropyl)-4-methylpiperazine end-capped poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based multilayers are promising for DNA release and intracellular delivery from a surface. PMID:23755861

(3-aminopropyl)-4-methylpiperazine end-capped poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based multilayer films for gene delivery.

Science.gov (United States)

Li, Cuicui; Tzeng, Stephany Y; Tellier, Liane E; Green, Jordan J

2013-07-10

Biodegradable polyelectrolyte surfaces for gene delivery were created through electrospinning of biodegradable polycations combined with iterative solution-based multilayer coating. Poly(β-amino ester) (PBAE) poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) end-capped with 1-(3-aminopropyl)-4-methylpiperazine was utilized because of its ability to electrostatically interact with anionic molecules like DNA, its biodegradability, and its low cytotoxicity. A new DNA release system was developed for sustained release of DNA over 24 h, accompanied by high exogenous gene expression in primary human glioblastoma (GB) cells. Electrospinning a different PBAE, poly(1,4-butanediol diacrylate-co-4,4'-trimethylenedipiperidine), and its combination with polyelectrolyte 1-(3-aminopropyl)-4-methylpiperazine end-capped poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based multilayers are promising for DNA release and intracellular delivery from a surface.

Assessment of proliferation resistances of aqueous reprocessing techniques using the TOPS methodology

International Nuclear Information System (INIS)

Åberg Lindell, M.; Grape, S.; Håkansson, A.; Jacobsson Svärd, S.

2013-01-01

Highlights: • Proliferation resistances of three possible LFR fuel cycles are assessed. • The TOPS methodology has been chosen for the PR assessment. • Reactor operation, reprocessing and fuel fabrication are examined. • Purex, Ganex, and a combination of Purex, Diamex and Sanex, are compared. • The safeguards analysis speaks in favor of Ganex as opposed to the Purex process. - Abstract: The aim of this study is to assess and compare the proliferation resistances (PR) of three possible Generation IV lead-cooled fast reactor fuel cycles, involving the reprocessing techniques Purex, Ganex and a combination of Purex, Diamex and Sanex, respectively. The examined fuel cycle stages are reactor operation, reprocessing and fuel fabrication. The TOPS methodology has been chosen for the PR assessment, and the only threat studied is the case where a technically advanced state diverts nuclear material covertly. According to the TOPS methodology, the facilities have been divided into segments, here roughly representing the different forms of nuclear material occurring in each examined fuel cycle stage. For each segment, various proliferation barriers have been assessed. The results make it possible to pinpoint where the facilities can be improved. The results show that the proliferation resistance of a fuel cycle involving recycling of minor actinides is higher than for the traditional Purex reprocessing cycle. Furthermore, for the purpose of nuclear safeguards, group actinide extraction should be preferred over reprocessing options where pure plutonium streams occur. This is due to the fact that a solution containing minor actinides is less attractive to a proliferator than a pure Pu solution. Thus, the safeguards analysis speaks in favor of Ganex as opposed to the Purex process

Water-soluble resorcin[4]arene based cavitands

NARCIS (Netherlands)

Grote gansey, M.H.B.; Grote Gansey, Marcel H.B.; Bakker, Frank K.G.; Feiters, Martinus C.; Geurts, Hubertus P.M.; Verboom, Willem; Reinhoudt, David

1998-01-01

Water-soluble resorcin[4]arene based cavitands were obtained in good yields by reaction of bromomethylcavitands with pyridine. Their solubility was determined by conductometry. The behaviour in water depends on the alkyl chain length; the methylcavitand does not aggregate, whereas the pentyl- and

Calix[4]arene Based Single-Molecule Magnets

Energy Technology Data Exchange (ETDEWEB)

Karotsis, Georgios; Teat, Simon J.; Wernsdorfer, Wolfgang; Piligkos, Stergios; Dalgarno, Scott J.; Brechin, Euan K.

2009-06-04

Single-molecule magnets (SMMs) have been the subject of much interest in recent years because their molecular nature and inherent physical properties allow the crossover between classical and quantum physics to be observed. The macroscopic observation of quantum phenomena - tunneling between different spin states, quantum interference between tunnel paths - not only allows scientists to study quantum mechanical laws in great detail, but also provides model systems with which to investigate the possible implementation of spin-based solid state qubits and molecular spintronics. The isolation of small, simple SMMs is therefore an exciting prospect. To date almost all SMMs have been made via the self-assembly of 3d metal ions in the presence of bridging/chelating organic ligands. However, very recently an exciting new class of SMMs, based on 3d metal clusters (or single lanthanide ions) housed within polyoxometalates, has appeared. These types of molecule, in which the SMM is completely encapsulated within (or shrouded by) a 'protective' organic or inorganic sheath have much potential for design and manipulation: for example, for the removal of unwanted dipolar interactions, the introduction of redox activity, or to simply aid functionalization for surface grafting. Calix[4]arenes are cyclic (typically bowl-shaped) polyphenols that have been used extensively in the formation of versatile self-assembled supramolecular structures. Although many have been reported, p-{sup t}But-calix[4]arene and calix[4]arene (TBC4 and C4 respectively, Figure 1A) are frequently encountered due to (a) synthetic accessibility, and (b) vast potential for alteration at either the upper or lower rim of the macrocyclic framework. Within the field of supramolecular chemistry, TBC4 is well known for interesting polymorphic behavior and phase transformations within anti-parallel bi-layer arrays, while C4 often forms self-included trimers. The polyphenolic nature of calix[n]arenes (where

A 4DCT imaging-based breathing lung model with relative hysteresis

Energy Technology Data Exchange (ETDEWEB)

Miyawaki, Shinjiro; Choi, Sanghun [IIHR – Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Hoffman, Eric A. [Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Medicine, The University of Iowa, Iowa City, IA 52242 (United States); Department of Radiology, The University of Iowa, Iowa City, IA 52242 (United States); Lin, Ching-Long, E-mail: ching-long-lin@uiowa.edu [IIHR – Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Mechanical and Industrial Engineering, The University of Iowa, 3131 Seamans Center, Iowa City, IA 52242 (United States)

2016-12-01

To reproduce realistic airway motion and airflow, the authors developed a deforming lung computational fluid dynamics (CFD) model based on four-dimensional (4D, space and time) dynamic computed tomography (CT) images. A total of 13 time points within controlled tidal volume respiration were used to account for realistic and irregular lung motion in human volunteers. Because of the irregular motion of 4DCT-based airways, we identified an optimal interpolation method for airway surface deformation during respiration, and implemented a computational solid mechanics-based moving mesh algorithm to produce smooth deforming airway mesh. In addition, we developed physiologically realistic airflow boundary conditions for both models based on multiple images and a single image. Furthermore, we examined simplified models based on one or two dynamic or static images. By comparing these simplified models with the model based on 13 dynamic images, we investigated the effects of relative hysteresis of lung structure with respect to lung volume, lung deformation, and imaging methods, i.e., dynamic vs. static scans, on CFD-predicted pressure drop. The effect of imaging method on pressure drop was 24 percentage points due to the differences in airflow distribution and airway geometry. - Highlights: • We developed a breathing human lung CFD model based on 4D-dynamic CT images. • The 4DCT-based breathing lung model is able to capture lung relative hysteresis. • A new boundary condition for lung model based on one static CT image was proposed. • The difference between lung models based on 4D and static CT images was quantified.

Targeting lysine specific demethylase 4A (KDM4A) tandem TUDOR domain - A fragment based approach.

Science.gov (United States)

Upadhyay, Anup K; Judge, Russell A; Li, Leiming; Pithawalla, Ron; Simanis, Justin; Bodelle, Pierre M; Marin, Violeta L; Henry, Rodger F; Petros, Andrew M; Sun, Chaohong

2018-06-01

The tandem TUDOR domains present in the non-catalytic C-terminal half of the KDM4A, 4B and 4C enzymes play important roles in regulating their chromatin localizations and substrate specificities. They achieve this regulatory role by binding to different tri-methylated lysine residues on histone H3 (H3-K4me3, H3-K23me3) and histone H4 (H4-K20me3) depending upon the specific chromatin environment. In this work, we have used a 2D-NMR based fragment screening approach to identify a novel fragment (1a), which binds to the KDM4A-TUDOR domain and shows modest competition with H3-K4me3 binding in biochemical as well as in vitro cell based assays. A co-crystal structure of KDM4A TUDOR domain in complex with 1a shows that the fragment binds stereo-specifically to the methyl lysine binding pocket forming a network of strong hydrogen bonds and hydrophobic interactions. We anticipate that the fragment 1a can be further developed into a novel allosteric inhibitor of the KDM4 family of enzymes through targeting their C-terminal tandem TUDOR domain. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anionic chromogenic chemosensors highly selective for fluoride or cyanide based on 4-(4-Nitrobenzylideneamine)phenol

OpenAIRE

Nicoleti,Celso R.; Marini,Vanderléia G.; Zimmermann,Lizandra M.; Machado,Vanderlei G.

2012-01-01

4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F- and CN-. Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN- over F- was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F-, leaving the CN- free to deprotonate the compound. A...

Synthesis of Schiff and Mannich Bases of Isatin Derivatives with 4-Amino-4,5-Dihydro-1H-1,2,4-Triazole-5-Ones

Directory of Open Access Journals (Sweden)

Hakan Bektas

2008-09-01

Full Text Available Ethyl imidate hydrochlorides 1 were prepared by passing HCl gas through solutions of substituted benzyl cyanides and absolute ethanol. Ethoxycarbonylhydrazones 2 were synthesized from the reaction of compounds 1 with ethyl carbazate. Treatment of 2 with hydrazine hydrate leads to the formation of substituted 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones 3. Isatin and 5-chloroisatin were added to 3 to form Schiff bases 4 and N-Mannich bases 5 of these compounds were synthesized by reacting with formaldehyde and piperidine. Their chemical structures were confirmed by means of IR, 1H- and 13C-NMR data and by elemental analysis.

A physically based constitutive model for a V-4Cr-4Ti alloy

International Nuclear Information System (INIS)

Donahue, E.G.; Odette, G.R.; Lucas, G.E.

2000-01-01

A constitutive model for low-to-intermediate temperatures, strains, and strain rates is developed for the program heat of V-4Cr-4Ti. The basic form of the model is derived from more general dislocation-based models of yield stress and strain hardening. The physically based forms are fit to a database derived from tensile tests carried out over a wide range of temperatures and strain rates. Yield and post-yield strain-hardening contributions to the flow stress are additive. The yield stress has both thermally activated and athermal components. The former is described by a two-mechanism activated dislocation slip model, with contributions that appear to arise from both lattice friction (at lower temperatures) and dislocation pinning by interstitial impurities (at higher temperatures). The yield stress data can be correlated using a strain rate-compensated temperature. The model uses a temperature-weighted average of the two mechanisms. Post-yield strain hardening was found to be approximately athermal. Strain hardening is fit to a two-component modified Voce-type saturating flow stress model. The constitutive model is also used to determine the flow stability limits as estimates of uniform tensile strains. The relatively compact, but mechanism-based, semi-empirical model has a number of both fundamental and practical advantages that are briefly outlined

3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

International Nuclear Information System (INIS)

Dhou, S; Hurwitz, M; Cai, W; Rottmann, J; Williams, C; Wagar, M; Berbeco, R; Lewis, J H; Mishra, P; Li, R; Ionascu, D

2015-01-01

3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we developed and performed initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and used these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparison to ground truth digital and physical phantom images. The performance of 4DCBCT-based and 4DCT-based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery. (paper)

DD4Hep based event reconstruction

CERN Document Server

AUTHOR|(SzGeCERN)683529; Frank, Markus; Gaede, Frank-Dieter; Hynds, Daniel; Lu, Shaojun; Nikiforou, Nikiforos; Petric, Marko; Simoniello, Rosa; Voutsinas, Georgios Gerasimos

The DD4HEP detector description toolkit offers a flexible and easy-to-use solution for the consistent and complete description of particle physics detectors in a single system. The sub-component DDREC provides a dedicated interface to the detector geometry as needed for event reconstruction. With DDREC there is no need to define an additional, separate reconstruction geometry as is often done in HEP, but one can transparently extend the existing detailed simulation model to be also used for the reconstruction. Based on the extension mechanism of DD4HEP, DDREC allows one to attach user defined data structures to detector elements at all levels of the geometry hierarchy. These data structures define a high level view onto the detectors describing their physical properties, such as measurement layers, point resolutions, and cell sizes. For the purpose of charged particle track reconstruction, dedicated surface objects can be attached to every volume in the detector geometry. These surfaces provide the measuremen...

Ideas: NCTM Standards-Based Instruction, Grades K-4.

Science.gov (United States)

Hynes, Michael C., Ed.

This document is a collection of activity-based mathematics lessons for grades K-4 from the "Ideas" department in "Arithmetic Teacher: Mathematics Education through the Middle Grades." Each lesson includes background information, objectives, directions, extensions, and student worksheets. A matrix is included which correlates…

(3-Aminopropyl)-4-methylpiperazine End-capped Poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based Multilayer Films for Gene Delivery

OpenAIRE

Li, Cuicui; Tzeng, Stephany Y; Tellier, Liane E.; Green, Jordan J

2013-01-01

Biodegradable polyelectrolyte surfaces for gene delivery were created through electrospinning of biodegradable polycations combined with iterative solution-based multilayer coating. Poly(β-amino ester) (PBAE) poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) end-capped with 1-(3-aminopropyl)-4-methylpiperazine was utilized due to its ability to electrostatically interact with anionic molecules like DNA, its biodegradability, and its low cytotoxicity. A new DNA release system was developed ...

A highly luminescent dinuclear Eu(III) complex based on 4,4'-bis (4'',4'',4''-trifluoro-1'',3''-dioxobutyl)-o-terphenyl for light-emitting diodes

International Nuclear Information System (INIS)

Liu Shenggui; He Pei; Wang Huihui; Shi Jianxin; Gong Menglian

2009-01-01

A dinuclear Eu(III) complex Eu 2 (btbt) 3 .4H 2 O.CH 3 CH 2 OH.N(CH 2 CH 3 ) 3 was synthesized, where H 2 (btbt) was 4,4'-bis (4'',4'',4'',-trifluoro-1'',3''-dioxobutyl)-o-terphenyl. The composition and structure of the complex were characterized by elemental analysis, IR, UV-vis and FAB-MS spectroscopy. The complex emits the characteristic red luminescence of Eu 3+ ion due to the 5 D 0 → 7 F J (J = 0-4) transitions under ∼395 nm-light excitation with good luminescent quantum efficiency (32%) and exhibits high thermal stability (337 deg. C). Bright red light-emitting diodes (LEDs) were fabricated by coating the complex onto a ∼395 nm-emitting InGaN chip. When the mass ratio of the red phosphor to the silicone is 1:30, the efficiency of the fabricated LEDs with the europium complex is 0.98 lm w -1 . The CIE chromaticity coordinates of the LEDs are x = 0.6057 and y = 0.3137, which are close to the National Television Standard Committee (NTSC) standard values for red color. The results indicate that the complex may act as a red component in the fabrication of near UV InGaN-based white light-emitting diodes with high color-rendering index.

Diversity of coordination modes in the polymers based on 3,3',4,4'-biphenylcarboxylate ligand

International Nuclear Information System (INIS)

Du Xiaodi; Xiao Hongping; Zhou Xinhui; Wu Tao; You Xiaozeng

2010-01-01

Four new compounds [Ni 2 (4,4'-bpy)(3,4-bptc)(H 2 O) 4 ] n (1), [Ni(4,4'-bpy)(3,4-H 2 bptc)(H 2 O) 3 ] n (2), [Mn 2 (2,2'-bpy) 4 (3,4-H 2 bptc) 2 ] (3) and {[Mn(1,10-phen) 2 (3,4-H 2 bptc)].4H 2 O} n (4) (3,4-H 4 bptc=3,3',4,4'-biphenyltetracarboxylic acid, 4,4'-bpy=4,4'-bipyridine, 2,2'-bpy=2,2'-bipyridine, 1, 10-phen=1, 10-phenanthroline), have been prepared and structurally characterized. In all compounds, the derivative ligands of 3,4-H 4 bptc (3,4-bptc 4- and 3,4-H 2 bptc 2- ) exhibit different coordination modes and lead to the formation of various architectures. Compounds 1 and 2 display the three-dimensional (3D) framework: 1 shows a 3,4-connected topological network with (8 3 )(8 5 .10) topology symbol based on the coordination bonds while in 2, the hydrogen-bonding interactions are observed to connect the 1D linear chain generating a final 3D framework. 3 exhibits the 2D layer constructed from the hydrogen-bonding interactions between the dinuclear manganese units. Complex 4 shows the double layers motif through connecting the 1D zigzag chains with hydrogen-bonded rings. The thermal stability of 1-4 and magnetic property of 1 were also reported. - Graphical abstract: Four coordination compounds exhibiting four coordination modes of the 3,3',4,4'-biphenylcarboxylate ligand, with three of new in this system, are obtained showing diversified architectures.

The discovery and the structural basis of an imidazo[4,5-b]pyridine-based p21-activated kinase 4 inhibitor.

Science.gov (United States)

Park, Jeung Kuk; Kim, Sunmin; Han, Yu Jin; Kim, Seong Hwan; Kang, Nam Sook; Lee, Hyuk; Park, SangYoun

2016-06-01

p21-Activated kinases (PAKs) which belong to the family of ste20 serine/threonine protein kinases regulate cytoskeletal reorganization, cell motility, cell proliferation, and oncogenic transformation which are all related to the cellular functions during cancer induction and metastasis. The fact that PAK mutations are detected in multiple tumor tissues makes PAKs a novel therapeutic drug target. In this study, an imidazo[4,5-b]pyridine-based PAK4 inhibitor, KY-04045 (6-Bromo-2-(3-isopropyl-1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-b]pyridine), was discovered using a virtual site-directed fragment-based drug design and was validated using an inhibition assay. Although PAK4 affinity to KY-04045 seems much weaker than that of the reported PAK4 inhibitors, the location of KY-04045 is clearly defined in the structure of PAK4 co-crystallized with KY-04045. The crystal structure illustrates that the pyrazole and imidazopyridine rings of KY-04045 are sufficient for mediating PAK4 hinge loop interaction. Hence, we believe that KY-04045 can be exploited as a basic building block in designing novel imidazo[4,5-b]pyridine-based PAK4 inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural Diversity of Metallosupramolecular Assemblies Based on the Bent Bridging Ligand 4,4′-Dithiodipyridine

Directory of Open Access Journals (Sweden)

Rüdiger W. Seidel

2013-05-01

Full Text Available 4,4′-Dithiodipyridine (dtdp, also termed 4,4′-dipyridyldisulfide, is a bridging ligand of the 4,4′-bipyridine type. The introduction of the disulfide moiety inevitably leads to a relatively rigid angular structure, which exhibits axial chirality. More than 90 metal complexes containing the dtdp ligand have been crystallographically characterised until now. This review focuses on the preparation and structural diversity of discrete and polymeric metallosupramolecular assemblies constructed from dtdp as bridging ligands. These encompass metallamacrocycles with M2L2 topology and coordination polymers with periodicity in one or two dimensions. One-dimensional coordination polymers represent the vast majority of the metallosupramolecular structures obtained from dtdp. These include repeated rhomboids, zigzag, helical and arched chains among other types. In this contribution, we make an attempt to provide a comprehensive account of the structural data that are currently available for metallosupramolecular assemblies based on the bent bridging ligand dtdp.

Electrochemical Polishing Applications and EIS of a Vitamin B4-Based Ionic Liquid

International Nuclear Information System (INIS)

Wixtrom, Alex I.; Buhler, Jessica E.; Reece, Charles E.; Abdel-Fattah, Tarek M.

2013-01-01

Modern particle accelerators require minimal interior surface roughness for Niobium superconducting radio frequency (SRF) cavities. Polishing of the Nb is currently achieved via electrochemical polishing with concentrated mixtures of sulfuric and hydrofluoric acids. This acid-based approach is effective at reducing the surface roughness to acceptable levels for SRF use, but due to acid-related hazards and extra costs (including safe disposal of used polishing solutions), an acid-free method would be preferable. This study focuses on an alternative electrochemical polishing method for Nb, using a novel ionic liquid solution containing choline chloride, also known as Vitamin B 4 (VB 4 ). Potentiostatic electrochemical impedance spectroscopy (EIS) was also performed on the VB4-based system. Nb polished using the VB4-based method was found to have a final surface roughness comparable to that achieved via the acid-based method, as assessed by atomic force microscopy (AFM). These findings indicate that acid-free VB 4 -based electrochemical polishing of Nb represents a promising replacement for acid-based methods of SRF cavity preparation

Energetics and dynamics of the non-natural fluorescent 4AP:DAP base pair

KAUST Repository

Chawla, Mohit

2018-01-02

The fluorescent non-natural 4-aminophthalimide (4AP) base, when paired to the complementary 2,4-diaminopyrimidine (DAP) nucleobase, is accommodated in a B-DNA duplex being efficiently recognized and incorporated by DNA polymerases. To complement the experimental studies and rationalize the impact of the above non-natural bases on the structure, stability and dynamics of nucleic acid structures, we performed quantum mechanics (QM) calculations along with classical molecular dynamics (MD) simulations. QM calculations were initially focused on the geometry and energetics of the 4AP:DAP non-natural pair and of H-bonded base pairs between 4AP and all the natural bases in their classical Watson-Crick geometries. The QM calculations indicate that the 4AP:DAP pair, despite the fact that it can form 3 H-bonds in a classic Watson-Crick geometry, has a stability comparable to the A:T pair. Then, we extended the study to reverse Watson-Crick geometries, characteristic of parallel strands. MD simulations were carried out on two 13-mer DNA duplexes, featuring a central 4AP:DAP or A:T pair, respectively. No major structural deformation of the duplex was observed during the MD simulation. Snapshots from the MD simulations were subjected to QM calculations to investigate the 4AP:DAP interaction energy when embedded into a duplex structure, and to investigate the impact of the two non-natural bases on the stacking interactions with adjacent bases in the DNA duplex. We found a slight increase in stacking interactions involving the 4AP:DAP pair, counterbalanced by a moderate decrease in H-bonding interactions of the 4AP:DAP and of the adjacent base pairs in the duplex. The results of our study are in agreement with experimental data and complement them by providing an insight into which factors contribute positively and which factors contribute negatively to the structural compatibility of the fluorescent 4AP:DAP pair with a B-DNA structure.

A review on g-C{sub 3}N{sub 4}-based photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Wen, Jiuqing; Xie, Jun [College of Materials and Energy, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, South China Agricultural University, Guangzhou, 510642 (China); Chen, Xiaobo, E-mail: chenxiaobo@umkc.edu [Department of Chemistry, University of Missouri – Kansas City, Kansas City, MO, 64110 (United States); Li, Xin, E-mail: Xinliscau@yahoo.com [College of Materials and Energy, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, South China Agricultural University, Guangzhou, 510642 (China)

2017-01-01

Graphical abstract: The photocatalytic fundamentals, versatile properties, design strategies and potential applications of g-C{sub 3}N{sub 4}-based photocatalysts were systematically summarized and addressed. - Highlights: • The photocatalytic fundamentals of g-C{sub 3}N{sub 4} were systematically summarized. • The versatile properties of g-C{sub 3}N{sub 4} photocatalysts were highlighted. • The different design strategies of g-C{sub 3}N{sub 4} photocatalysts were reviewed. • The important photocatalytic applications of g-C{sub 3}N{sub 4} were also addressed. - Abstract: As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C{sub 3}N{sub 4}-based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C{sub 3}N{sub 4}-based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C{sub 3}N{sub 4}-based photocatalysts. The versatile properties of g-C{sub 3}N{sub 4}-based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H{sub 2} evolution and overall water

Inherently balanced 4R four-bar based linkages

NARCIS (Netherlands)

van der Wijk, V.; Herder, Justus Laurens; Lenarcis, J.; Husty, M.

2012-01-01

Synthesis of mechanisms with their center of mass (CoM) at an invariant point on one of the elements is useful for the design of statically balanced and shaking-force balanced mechanisms and manipulators. For this purpose, a kinematic architecture based on a general 4R four-bar linkage is found by

BoHV-4-based vector delivering Ebola virus surface glycoprotein

Directory of Open Access Journals (Sweden)

Alfonso Rosamilia

2016-11-01

Full Text Available Abstract Background Ebola virus (EBOV is a Category A pathogen that is a member of Filoviridae family that causes hemorrhagic fever in humans and non-human primates. Unpredictable and devastating outbreaks of disease have recently occurred in Africa and current immunoprophylaxis and therapies are limited. The main limitation of working with pathogens like EBOV is the need for costly containment. To potentiate further and wider opportunity for EBOV prophylactics and therapies development, innovative approaches are necessary. Methods In the present study, an antigen delivery platform based on a recombinant bovine herpesvirus 4 (BoHV-4, delivering a synthetic EBOV glycoprotein (GP gene sequence, BoHV-4-syEBOVgD106ΔTK, was generated. Results EBOV GP was abundantly expressed by BoHV-4-syEBOVgD106ΔTK transduced cells without decreasing viral replication. BoHV-4-syEBOVgD106ΔTK immunized goats produced high titers of anti-EBOV GP antibodies and conferred a long lasting (up to 6 months, detectable antibody response. Furthermore, no evidence of BoHV-4-syEBOVgD106ΔTK viremia and secondary localization was detected in any of the immunized animals. Conclusions The BoHV-4-based vector approach described here, represents: an alternative antigen delivery system for vaccination and a proof of principle study for anti-EBOV antibodies generation in goats for potential immunotherapy applications.

Identification of quinazoline based inhibitors of IRAK4 for the treatment of inflammation

Energy Technology Data Exchange (ETDEWEB)

Smith, Graham F.; Altman, Michael D.; Andresen, Brian; Baker, James; Brubaker, Jason D.; Chen, Hongmin; Chen, Yiping; Childers, Matthew; Donofrio, Anthony; Ferguson, Heidi; Fischer, Christian; Fischmann, Thierry O.; Gibeau, Craig; Hicks, Alexander; Jin, Sue; Kattar, Sam; Kleinschek, Melanie A.; Leccese, Erica; Lesburg, Charles; Li, Chaomin; Lim, Jongwon; Liu, Duan; Maclean, John K.F.; Mansoor, Faruk; Moy, Lilly Y.; Mulrooney, Erin F.; Necheva, Antoaneta S.; Presland, Jeremy; Rakhilina, Larissa; Yang, Ruojing; Torres, Luis; Zhang-Hoover, Jie; Northrup, Alan (Merck); (Oncorus); (Theravance Biopharma); (AstraZeneca); (Blueprint Medicines)

2017-06-01

Interleukin-1 receptor associated kinase 4 (IRAK4) has been implicated in IL-1R and TLR based signaling. Therefore selective inhibition of the kinase activity of this protein represents an attractive target for the treatment of inflammatory diseases. Medicinal chemistry optimization of high throughput screening (HTS) hits with the help of structure based drug design led to the identification of orally-bioavailable quinazoline based IRAK4 inhibitors with excellent pharmacokinetic profile and kinase selectivity. These highly selective IRAK4 compounds show activity in vivo via oral dosing in a TLR7 driven model of inflammation.

Anionic chromogenic chemosensors highly selective for fluoride or cyanide based on 4-(4-Nitrobenzylideneamine)phenol

Energy Technology Data Exchange (ETDEWEB)

Nicoleti, Celso R; Marini, Vanderleia G; Zimmermann, Lizandra M; Machado, Vanderlei G., E-mail: vanderlei.machado@ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

2012-08-15

4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F{sup -} and CN{sup -}. Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN{sup -} over F{sup -} was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F{sup -}, leaving the CN{sup -} free to deprotonate the compound. Another strategy involved an assay comprised of the competition between phenolate dye and the analyte for calyx[4]pyrrole in acetonitrile, a receptor highly selective for F{sup -}. Phenolate and calyx[4]pyrrole form a hydrogen-bonded complex, which changes the color of the medium. On the addition of various anions, only F{sup -} was able to restore the original color corresponding to phenolate in solution due to the fact that the anion dislodges phenolate from the complexation site. (author)

Anionic chromogenic chemosensors highly selective for fluoride or cyanide based on 4-(4-Nitrobenzylideneamine)phenol

International Nuclear Information System (INIS)

Nicoleti, Celso R.; Marini, Vanderleia G.; Zimmermann, Lizandra M.; Machado, Vanderlei G.

2012-01-01

4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F - and CN - . Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN - over F - was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F - , leaving the CN - free to deprotonate the compound. Another strategy involved an assay comprised of the competition between phenolate dye and the analyte for calyx[4]pyrrole in acetonitrile, a receptor highly selective for F - . Phenolate and calyx[4]pyrrole form a hydrogen-bonded complex, which changes the color of the medium. On the addition of various anions, only F - was able to restore the original color corresponding to phenolate in solution due to the fact that the anion dislodges phenolate from the complexation site. (author)

Phylogeny of Celastrus L. (Celastraceae) inferred from two nuclear and three plastid markers.

Science.gov (United States)

Mu, Xian-Yun; Zhao, Liang-Cheng; Zhang, Zhi-Xiang

2012-09-01

This is the first comprehensive molecular investigation of the genus Celastrus L. Phylogenetic relationships within the genus were assessed based on sequences of two nuclear (ETS, ITS) and three plastid (psbA-trnH, rpl16 and trnL-F) regions using the Bayesian inference and the maximum parsimony methods. Our results show that Celastrus, together with Tripterygium, formed a maximal supported clade. Within the cluster, Celastrus is composed of a basal clade and a core Celastrus clade, and the latter is consisted of six subclades. Relationships among species are more influenced by latitude than continental distribution patterns. The cauline cyme and lunate seeds are distinct characters to one of the maximal supported subclades. Their close relationship, similar geographical pattern and habitat imply that C. flagellaris may be a potential invasive species threatening C. scandens in North America. Celastrus leiocarpus, C. oblanceifolius and C. rugosus are confirmed as synonyms of C. punctatus, C. aculeatus and C. glaucophyllus, respectively. Discordance between the molecular data and previous morphology-based subgeneric classifications are noted. More works are needed to clarify the relationship between Celastrus and Tripterygium and the species within Celastrus.

12 CFR 956.4 - Risk-based capital requirement for investments.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for investments... OFF-BALANCE SHEET ITEMS FEDERAL HOME LOAN BANK INVESTMENTS § 956.4 Risk-based capital requirement for investments. Each Bank shall hold retained earnings plus general allowance for losses as support for the...

Radioactive wastes. Management prospects. Appendixes

International Nuclear Information System (INIS)

Guillaumont, R.

2003-01-01

These appendixes complete the article BN3661 entitled 'Radioactive wastes. Management prospects'. They develop the principles of the different separation processes under study and make a status of the conditioning matrices that are envisaged: 1 - principles of advanced separation (separation of U, Np, Pu, Tc and I; separation of Am and Cm in two extraction steps (Diamex and Sanex processes); separation of Am and Cm in a single extraction step (Paladin process); separation of Am and Cm (Sesame process); separation of Cs (Calixarene process); 2 - principles of separation in pyro-chemistry: separation under inert atmosphere (non-oxidizing); separation in oxidizing conditions; 3 - conditioning matrices under study for separate elements: objectives and methodology, matrices for iodine, for cesium and for actinides. (J.S.)

Spin resonance in the new-structure-type iron-based superconductor CaKFe4As4

International Nuclear Information System (INIS)

Iida, Kazuki; Ishikado, Motoyuki; Nagai, Yuki; Yoshida, Hiroyuki; Christianson, Andrew D.; Murai, Naoki; Kawashima, Kenji; Yoshida, Yoshiyuki; Eisaki, Hiroshi; Iyo, Akira

2017-01-01

The dynamical spin susceptibility in the new-structure-type iron-based superconductor CaKFe 4 As 4 was investigated by using a combination of inelastic neutron scattering (INS) measurements and random phase approximation (RPA) calculations. Powder INS measurements show that the spin resonance at Q res = 1.17(1) Å -1 , corresponding to the (π, π) nesting wave vector in tetragonal notation, evolves below T c . The characteristic energy of the spin resonance E res = 12.5 meV is smaller than twice the size of the superconducting gap (2Δ). The broad energy feature of the dynamical susceptibility of the spin resonance can be explained by the RPA calculations, in which the different superconducting gaps on different Fermi surfaces are taken into account. Our INS and PRA studies demonstrate that the superconducting pairing nature in CaKFe 4 As 4 is the s ± symmetry. (author)

Optimizing Memory Usage in L4-Based Microkernel

OpenAIRE

Petre Eftime; Lucian Mogoşanu; Mihai Carabaş; Răzvan Deaconescu; Laura Gheorghe; Valentin Gabriel Voiculescu

2017-01-01

Memory allocation is a critical aspect of any modern operating system kernel because it must run continuously for long periods of time, therefore memory leaks and inefficiency must be eliminated. This paper presents different memory management algorithms and their aplicability to an L4-based microkernel. We aim to reduce memory usage and increase the performance of allocation and deallocation of memory.

Removal of 4-Ethylphenol and 4-Ethylguaiacol with Polyaniline-Based Compounds in Wine-Like Model Solutions and Red Wine

Directory of Open Access Journals (Sweden)

Verónica Carrasco-Sánchez

2015-08-01

Full Text Available Volatile phenols, such as 4-ethyphenol (4-EP and 4-ethylguaiacol (4-EG, are responsible for the “Brett character” found in wines contaminated with Brettanomyces yeast (i.e., barnyard, animal, spicy and smoky aromas. In these trials, we explore the effectiveness of polyaniline-based compounds (polyaniline emeraldin salt (PANI-ES and polyanaline emeraldin base (PANI-EB, for the removal of 4-EP and 4-EG from acidic model solutions and red wine. First, a screening study, performed in an acidified 12% ethanol solution, was used to optimize parameters such as contact time and the amount of polymers required to remove 4-EP and 4-EG. Then, the trapping ability of PANI agents towards 4-EP and 4-EG was evaluated in a model solution containing other wine phenolics that could potentially be trapped by PANI (i.e., gallic acid and 4-methylcatechol. The results of this trial showed that both PANI compounds were capable of removing 4-EP, 4-EG, regardless of the presence of other phenolic compounds present at a much higher concentration. Finally, the capturing ability of PANI was evaluated in a red wine sample containing 5 mg·L−1 of 4-EP, 5 mg·L−1 of 4-EG and 2.03 ± 0.02 g·L−1 of total phenolics. The results showed that PANI-EB removed significantly more 4-EP and 4-EG than PANI-ES. For instance, a treatment with 10 mg·mL−1 of PANI-EB produced a 67.8% reduction of 4-EP, 50% reduction of 4-EG and 41.38% decrease in total phenols.

Conformations of stereoisomeric base adducts to 4-hydroxyequilenin.

Science.gov (United States)

Ding, Shuang; Shapiro, Robert; Geacintov, Nicholas E; Broyde, Suse

2003-06-01

Exposure to estrogen through estrogen replacement therapy increases the risk of women developing cancer in hormone sensitive tissues. Premarin (Wyeth), which has been the most frequent choice for estrogen replacement therapy in the United States, contains the equine estrogens equilin and equilenin as major components. 4-Hydroxyequilenin (4-OHEN) is a phase I metabolite of both of these substances. This catechol estrogen autoxidizes to potent cytotoxic quinoids that can react with dG, dA, and dC to form unusual stereoisomeric cyclic adducts (Bolton, J. L., et al. (1998) Chem. Res. Toxicol. 11, 1113-1127). Like other bulky DNA adducts, these lesions may exhibit different susceptibilities to DNA repair and mutagenic potential, if not repaired in a structure-dependent manner. To ultimately gain insights into structure-function relationships, we computed conformations of stereoisomeric guanine, adenine, and cytosine base adducts using density functional theory. We find near mirror image conformations in stereoisomer adduct pairs for each modified base, suggesting opposite orientations with respect to the 5' --> 3' direction of the modified strand when the stereoisomer pairs are incorporated into duplex DNA. Such opposite orientations could cause stereoisomer pairs of lesions to respond differently to DNA replication and repair enzymes.

Development of an immunoassay for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) based upon the recombinant Fab fragment of 2,4-D specific antibody

Science.gov (United States)

Nguyen, Van C.; Nguyen, Thi D. T.; Dau, Hung A.; Tham, Thu N.; Quyen, Dinh T.; Bachmman, Till; Schmid, Rolf D.

2001-09-01

To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

Quantitative Structure-Retention Relationships (QSRR) for Chromatographic Separation of Disazo and Trisazo 4,4'-Diaminobenzanilide-based Dyes

OpenAIRE

Funar-Timofei, Simona; Fabian, Walter M. F.; Simu, Georgeta M.; Suzukic, Takahiro

2006-01-01

For a series of 23 disazo and trisazo 4,4'-diaminobenzanilide-based direct dye molecules, thechromatographic mobilities, extrapolated to modifier-free conditions (RM0 values), were determinedfrom reverse-phase thin-layer chromatography (RP-TLC) experiments. Traditional and rational QSAR/QSPR modelling techniques have been applied to find a quantitative structure-retention relationship (QSRR) for the dyes. Molecular dye structures were energy minimized by both molecular mechanics and quantum c...

A probability-based multi-cycle sorting method for 4D-MRI: A simulation study.

Science.gov (United States)

Liang, Xiao; Yin, Fang-Fang; Liu, Yilin; Cai, Jing

2016-12-01

To develop a novel probability-based sorting method capable of generating multiple breathing cycles of 4D-MRI images and to evaluate performance of this new method by comparing with conventional phase-based methods in terms of image quality and tumor motion measurement. Based on previous findings that breathing motion probability density function (PDF) of a single breathing cycle is dramatically different from true stabilized PDF that resulted from many breathing cycles, it is expected that a probability-based sorting method capable of generating multiple breathing cycles of 4D images may capture breathing variation information missing from conventional single-cycle sorting methods. The overall idea is to identify a few main breathing cycles (and their corresponding weightings) that can best represent the main breathing patterns of the patient and then reconstruct a set of 4D images for each of the identified main breathing cycles. This method is implemented in three steps: (1) The breathing signal is decomposed into individual breathing cycles, characterized by amplitude, and period; (2) individual breathing cycles are grouped based on amplitude and period to determine the main breathing cycles. If a group contains more than 10% of all breathing cycles in a breathing signal, it is determined as a main breathing pattern group and is represented by the average of individual breathing cycles in the group; (3) for each main breathing cycle, a set of 4D images is reconstructed using a result-driven sorting method adapted from our previous study. The probability-based sorting method was first tested on 26 patients' breathing signals to evaluate its feasibility of improving target motion PDF. The new method was subsequently tested for a sequential image acquisition scheme on the 4D digital extended cardiac torso (XCAT) phantom. Performance of the probability-based and conventional sorting methods was evaluated in terms of target volume precision and accuracy as measured

Structure of 2,4-Diaminopyrimidine - Theobromine Alternate Base Pairs

Science.gov (United States)

Gengeliczki, Zsolt; Callahan, Michael P.; Kabelac, Martin; Rijs, Anouk M.; deVries, Mattanjah S.

2011-01-01

We report the structure of clusters of 2,4-diaminopyrimidine with 3,7-dimethylxanthine (theobromine) in the gas phase determined by IR-UV double resonance spectroscopy in both the near-IR and mid-IR regions in combination with ab initio computations. These clusters represent potential alternate nucleobase pairs, geometrically equivalent to guanine-cytosine. We have found the four lowest energy structures, which include the Watson-Crick base pairing motif. This Watson-Crick structure has not been observed by resonant two-photon ionization (R2PI) in the gas phase for the canonical DNA base pairs.

Synthesis of formazans from Mannich base of 5-(4-chlorophenyl amino-2-mercapto-1,3,4-thiadiazole as antimicrobial agents

Directory of Open Access Journals (Sweden)

Pramilla Sah

2014-04-01

Full Text Available 5-(4-Chlorophenyl amino-2-mercapto-1,3,4-thiadiazole (I was refluxed with formaldehyde and ammonium chloride in ethanol yielding the Mannich base 5-(4-chloro phenyl amino-3-aminomethyl-2-mercapto-1,3,4-thiadiazole (II. Esterification with 4-chloro-(2,6-dinitro phenoxy-ethyl acetate (III under anhydrous conditions gave the intermediate (IV. Subsequent hydrazinolysis with hydrazine hydrate gave the corresponding hydrazide 3-amino methyl-5-(4-chloro phenyl amino-2-mercapto-4′-(2′,6′-dinitro phenoxy-acetyl hydrazide (V. The hydrazide was converted into the Schiff bases (VIa–b by reacting with 2-chlorobenzaldehyde and 3-methoxy-4-hydroxy benzaldehyde in presence of methanol containing 2–3 drops of acetic acid. Diazotisation with aromatic amines, sulphanilic acid and sulphur drugs gave the formazans (VIIa–g respectively. Chemical structures have been established by elemental analysis and the spectral techniques of FTIR, 1H NMR and mass. Antimicrobial activity (in vitro was evaluated against the two pathogenic bacterial strains. Escherichia coli and Salmonella typhi, three fungal strains Aspergillus niger, Penicillium species and Candida albicans. The compounds have shown moderate activity.

Cure4Kids for Kids: school-based cancer education outreach.

Science.gov (United States)

Van Kirk Villalobos, Aubrey; Quintana, Yuri; Ribeiro, Raul C

2012-01-01

In 2006, St. Jude Children's Research Hospital created Cure4Kids for Kids, a school-based outreach program. The objectives of this community education program are to teach about cancer and healthy lifestyles and to inspire an interest in science and health-related careers. A multidisciplinary team of St. Jude and outside experts developed and pilot tested age-appropriate educational materials and activities with 4th grade students. Eight schools and more than 800 children have participated in the program since 2006. Teachers and students have demonstrated a very positive response to the program for it being both fun and educational. Cure4Kids for Kids resources have been collected into a teacher's kit and are now freely available online at www.cure4kids.org/kids.

Tribological characteristics of Si3N4-based composites in unlubricated sliding against steel ball

International Nuclear Information System (INIS)

Liu, C.-C.; Huang, J.-L.

2004-01-01

The dry-sliding wear mechanism of Si 3 N 4 -based composites against AISI-52100 steel ball was studied using a ball-on-disc mode in a reciprocation motion. The addition of TiN particles can increase the fracture toughness of Si 3 N 4 -based composites. The fracture toughness of Si 3 N 4 -based composites played an important role for wear behavior. The Si 3 N 4 -based composites exhibits a small friction and wear coefficient compared to monolithic Si 3 N 4 . Atomic force microscopy (AFM) studies displayed fine wear grooves along the sliding traces. The subsurface deformation shows that the microcrack propagation extends along the TiN/Si 3 N 4 grain interface. The wear mechanisms were determined with scanning electron microscopy, transmission electron microscopy, X-ray diffraction and atomic force microscopy

Optical and Thermal Behaviors of Polyamide-Layered Silicate Nanocomposites Based on 4,4'-Azodibenzoic Acid by Solution Intercalation Technique

Science.gov (United States)

Faghihi, Khalil; Shabanian, Meisam

2011-04-01

Two new samples of polyamide-montmorillonite reinforced nanocomposites based on 4,4'-azodibenzoic acid were prepared by a convenient solution intercalation technique. Polyamide (PA) 4 as a source of polymer matrix was synthesized by the direct polycondensation reaction of 4,4'-azodibenzoic acid 2 with 4,4'-diamino diphenyl sulfone 3 in the presence of triphenyl phosphate (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PA-nanocomposite films 4a and 4b with 10 and 20% silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

SVMDLF: A novel R-based Web application for prediction of dipeptidyl peptidase 4 inhibitors.

Science.gov (United States)

Chandra, Sharat; Pandey, Jyotsana; Tamrakar, Akhilesh K; Siddiqi, Mohammad Imran

2017-12-01

Dipeptidyl peptidase 4 (DPP4) is a well-known target for the antidiabetic drugs. However, currently available DPP4 inhibitor screening assays are costly and labor-intensive. It is important to create a robust in silico method to predict the activity of DPP4 inhibitor for the new lead finding. Here, we introduce an R-based Web application SVMDLF (SVM-based DPP4 Lead Finder) to predict the inhibitor of DPP4, based on support vector machine (SVM) model, predictions of which are confirmed by in vitro biological evaluation. The best model generated by MACCS structure fingerprint gave the Matthews correlation coefficient of 0.87 for the test set and 0.883 for the external test set. We screened Maybridge database consisting approximately 53,000 compounds. For further bioactivity assay, six compounds were shortlisted, and of six hits, three compounds showed significant DPP4 inhibitory activities with IC 50 values ranging from 8.01 to 10.73 μm. This application is an OpenCPU server app which is a novel single-page R-based Web application for the DPP4 inhibitor prediction. The SVMDLF is freely available and open to all users at http://svmdlf.net/ocpu/library/dlfsvm/www/ and http://www.cdri.res.in/svmdlf/. © 2017 John Wiley & Sons A/S.

Ibrutinib Dosing Strategies Based on Interaction Potential of CYP3A4 Perpetrators Using Physiologically Based Pharmacokinetic Modeling.

Science.gov (United States)

de Zwart, L; Snoeys, J; De Jong, J; Sukbuntherng, J; Mannaert, E; Monshouwer, M

2016-11-01

Based on ibrutinib pharmacokinetics and potential sensitivity towards CYP3A4-mediated drug-drug interactions (DDIs), a physiologically based pharmacokinetic approach was developed to mechanistically describe DDI with various CYP3A4 perpetrators in healthy men under fasting conditions. These models were verified using clinical data for ketoconazole (strong CYP3A4 inhibitor) and used to prospectively predict and confirm the inducing effect of rifampin (strong CYP3A4 inducer); DDIs with mild (fluvoxamine, azithromycin) and moderate inhibitors (diltiazem, voriconazole, clarithromycin, itraconazole, erythromycin), and moderate (efavirenz) and strong CYP3A4 inducers (carbamazepine), were also predicted. Ketoconazole increased ibrutinib area under the curve (AUC) by 24-fold, while rifampin decreased ibrutinib AUC by 10-fold; coadministration of ibrutinib with strong inhibitors or inducers should be avoided. The ibrutinib dose should be reduced to 140 mg (quarter of maximal prescribed dose) when coadministered with moderate CYP3A4 inhibitors so that exposures remain within observed ranges at therapeutic doses. Thus, dose recommendations for CYP3A4 perpetrator use during ibrutinib treatment were developed and approved for labeling. © 2016 American Society for Clinical Pharmacology and Therapeutics.

Reducing 4D CT artifacts using optimized sorting based on anatomic similarity.

Science.gov (United States)

Johnston, Eric; Diehn, Maximilian; Murphy, James D; Loo, Billy W; Maxim, Peter G

2011-05-01

Four-dimensional (4D) computed tomography (CT) has been widely used as a tool to characterize respiratory motion in radiotherapy. The two most commonly used 4D CT algorithms sort images by the associated respiratory phase or displacement into a predefined number of bins, and are prone to image artifacts at transitions between bed positions. The purpose of this work is to demonstrate a method of reducing motion artifacts in 4D CT by incorporating anatomic similarity into phase or displacement based sorting protocols. Ten patient datasets were retrospectively sorted using both the displacement and phase based sorting algorithms. Conventional sorting methods allow selection of only the nearest-neighbor image in time or displacement within each bin. In our method, for each bed position either the displacement or the phase defines the center of a bin range about which several candidate images are selected. The two dimensional correlation coefficients between slices bordering the interface between adjacent couch positions are then calculated for all candidate pairings. Two slices have a high correlation if they are anatomically similar. Candidates from each bin are then selected to maximize the slice correlation over the entire data set using the Dijkstra's shortest path algorithm. To assess the reduction of artifacts, two thoracic radiation oncologists independently compared the resorted 4D datasets pairwise with conventionally sorted datasets, blinded to the sorting method, to choose which had the least motion artifacts. Agreement between reviewers was evaluated using the weighted kappa score. Anatomically based image selection resulted in 4D CT datasets with significantly reduced motion artifacts with both displacement (P = 0.0063) and phase sorting (P = 0.00022). There was good agreement between the two reviewers, with complete agreement 34 times and complete disagreement 6 times. Optimized sorting using anatomic similarity significantly reduces 4D CT motion

Establishment of a rabbit Oct4 promoter-based EGFP reporter system.

Directory of Open Access Journals (Sweden)

Longquan Quan

Full Text Available Rabbits are commonly used as laboratory animal models to investigate human diseases and phylogenetic development. However, pluripotent stem cells that contribute to germline transmission have yet to be established in rabbits. The transcription factor Oct4, also known as Pou5f1, is considered essential for the maintenance of the pluripotency of stem cells. Hence, pluripotent cells can be identified by monitoring Oct4 expression using a well-established Oct4 promoter-based reporter system. This study developed a rabbit Oct4 promoter-based enhanced green fluorescent protein (EGFP reporter system by transfecting pROP2-EGFP into rabbit fetal fibroblasts (RFFs. The transgenic RFFs were used as donor cells for somatic cell nuclear transfer (SCNT. The EGFP expression was detected in the blastocysts and genital ridges of SCNT fetuses. Fibroblasts and neural stem cells (NSCs were derived from the SCNT fetuses. EGFP was also reactivated in blastocysts after the second SCNT, and induced pluripotent stem cells (iPSCs were obtained after reprogramming using Yamanaka's factors. The results above indicated that a rabbit reporter system used to monitor the differentiating status of cells was successfully developed.

4D cone beam CT-based dose assessment for SBRT lung cancer treatment

International Nuclear Information System (INIS)

Cai, Weixing; Dhou, Salam; Cifter, Fulya; Myronakis, Marios; Hurwitz, Martina H; Williams, Christopher L; Berbeco, Ross I; Seco, Joao; Lewis, John H

2016-01-01

The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose using time-varying (‘fluoroscopic’) 3D patient images generated from a 4DCBCT-based motion model. The method includes four steps: (1) before each treatment, 4DCBCT data is acquired with the patient in treatment position, based on which a patient-specific motion model is created using a principal components analysis algorithm. (2) During treatment, 2D time-varying kV projection images are continuously acquired, from which time-varying ‘fluoroscopic’ 3D images of the patient are reconstructed using the motion model. (3) Lateral truncation artifacts are corrected using planning 4DCT images. (4) The 3D dose distribution is computed for each timepoint in the set of 3D fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach is validated using six modified XCAT phantoms with lung tumors and different respiratory motions derived from patient data. The estimated doses are compared to that calculated using ground-truth XCAT phantoms. For each XCAT phantom, the calculated delivered tumor dose values generally follow the same trend as that of the ground truth and at most timepoints the difference is less than 5%. For the overall delivered dose, the normalized error of calculated 3D dose distribution is generally less than 3% and the tumor D95 error is less than 1.5%. XCAT phantom studies indicate the potential of the proposed method to accurately estimate 3D tumor dose distributions for SBRT lung treatment based on 4DCBCT imaging and motion modeling. Further research is necessary to investigate its performance for clinical patient data. (paper)

FR4-Based Electromagnetic Scanning Micromirror Integrated with Angle Sensor

Directory of Open Access Journals (Sweden)

Hongjie Lei

2018-05-01

Full Text Available This paper presents a flame retardant 4 (FR4-based electromagnetic scanning micromirror, which aims to overcome the limitations of conventional microelectromechanical systems (MEMS micromirrors for the large-aperture and low-frequency scanning applications. This micromirror is fabricated through a commercial printed circuit board (PCB technology at a low cost and with a short process cycle, before an aluminum-coated silicon mirror plate with a large aperture is bonded on the FR4 platform to provide a high surface quality. In particular, an electromagnetic angle sensor is integrated to monitor the motion of the micromirror in real time. A prototype has been assembled and tested. The results show that the micromirror can reach the optical scan angle of 11.2 ∘ with a low driving voltage of only 425 mV at resonance (361.8 Hz. At the same time, the signal of the integrated angle sensor also shows good signal-to-noise ratio, linearity and sensitivity. Finally, the reliability of the FR4 based micro-mirror has been tested. The prototype successfully passes both shock and vibration tests. Furthermore, the results of the long-term mechanical cycling test (50 million cycles suggest that the maximum variations of resonant frequency and scan angle are less than 0.3% and 6%, respectively. Therefore, this simple and robust micromirror has great potential in being useful in a number of optical microsystems, especially when large-aperture or low-frequency is required.

Synthesis and dyeing performance of bisazo disperse dyes based on 3-[4-(4-amino-2-chlorophenoxyanilino]phenol

Directory of Open Access Journals (Sweden)

Rajesh H. Parab

2016-09-01

Full Text Available The present communication aims to develop bisazo disperse dyes based on 3-[4-(4-amino-2-chlorophenoxyanilino]phenol (DAP both as a coupling component as well as a diazonium salt. Coupling reaction of DAP was carried out with a diazonium salt of 4-aminoacetanilide to yield a monoazo disperse dye, and then it was further used as a diazonium salt and coupled with a different aromatic phenol to synthesize bisazo disperse dyes. All the disperse dyes were characterized by elemental analysis, IR, NMR and UV–Visible spectral studies with a view to determine their chemical structure. The dyeing ability of these bisazo disperse dyes has been evaluated in terms of their dyeing behavior and fastness properties on different fabrics.

Adaptive 4d Psi-Based Change Detection

Science.gov (United States)

Yang, Chia-Hsiang; Soergel, Uwe

2018-04-01

In a previous work, we proposed a PSI-based 4D change detection to detect disappearing and emerging PS points (3D) along with their occurrence dates (1D). Such change points are usually caused by anthropic events, e.g., building constructions in cities. This method first divides an entire SAR image stack into several subsets by a set of break dates. The PS points, which are selected based on their temporal coherences before or after a break date, are regarded as change candidates. Change points are then extracted from these candidates according to their change indices, which are modelled from their temporal coherences of divided image subsets. Finally, we check the evolution of the change indices for each change point to detect the break date that this change occurred. The experiment validated both feasibility and applicability of our method. However, two questions still remain. First, selection of temporal coherence threshold associates with a trade-off between quality and quantity of PS points. This selection is also crucial for the amount of change points in a more complex way. Second, heuristic selection of change index thresholds brings vulnerability and causes loss of change points. In this study, we adapt our approach to identify change points based on statistical characteristics of change indices rather than thresholding. The experiment validates this adaptive approach and shows increase of change points compared with the old version. In addition, we also explore and discuss optimal selection of temporal coherence threshold.

Simulation of spatiotemporal CT data sets using a 4D MRI-based lung motion model.

Science.gov (United States)

Marx, Mirko; Ehrhardt, Jan; Werner, René; Schlemmer, Heinz-Peter; Handels, Heinz

2014-05-01

Four-dimensional CT imaging is widely used to account for motion-related effects during radiotherapy planning of lung cancer patients. However, 4D CT often contains motion artifacts, cannot be used to measure motion variability, and leads to higher dose exposure. In this article, we propose using 4D MRI to acquire motion information for the radiotherapy planning process. From the 4D MRI images, we derive a time-continuous model of the average patient-specific respiratory motion, which is then applied to simulate 4D CT data based on a static 3D CT. The idea of the motion model is to represent the average lung motion over a respiratory cycle by cyclic B-spline curves. The model generation consists of motion field estimation in the 4D MRI data by nonlinear registration, assigning respiratory phases to the motion fields, and applying a B-spline approximation on a voxel-by-voxel basis to describe the average voxel motion over a breathing cycle. To simulate a patient-specific 4D CT based on a static CT of the patient, a multi-modal registration strategy is introduced to transfer the motion model from MRI to the static CT coordinates. Differences between model-based estimated and measured motion vectors are on average 1.39 mm for amplitude-based binning of the 4D MRI data of three patients. In addition, the MRI-to-CT registration strategy is shown to be suitable for the model transformation. The application of our 4D MRI-based motion model for simulating 4D CT images provides advantages over standard 4D CT (less motion artifacts, radiation-free). This makes it interesting for radiotherapy planning.

SQoS based Planning using 4-regular Grid for Optical Fiber Metworks

DEFF Research Database (Denmark)

Riaz, Muhammad Tahir; Pedersen, Jens Myrup; Madsen, Ole Brun

optical fiber based network infrastructures. In the first step of SQoS based planning, this paper describes how 4-regular Grid structures can be implemented in the physical level of optical fiber network infrastructures. A systematic approach for implementing the Grid structure is presented. We used...

SQoS based Planning using 4-regular Grid for Optical Fiber Networks

DEFF Research Database (Denmark)

Riaz, Muhammad Tahir; Pedersen, Jens Myrup; Madsen, Ole Brun

2005-01-01

optical fiber based network infrastructures. In the first step of SQoS based planning, this paper describes how 4-regular Grid structures can be implemented in the physical level of optical fiber network infrastructures. A systematic approach for implementing the Grid structure is presented. We used...

SU-D-207-04: GPU-Based 4D Cone-Beam CT Reconstruction Using Adaptive Meshing Method

International Nuclear Information System (INIS)

Zhong, Z; Gu, X; Iyengar, P; Mao, W; Wang, J; Guo, X

2015-01-01

Purpose: Due to the limited number of projections at each phase, the image quality of a four-dimensional cone-beam CT (4D-CBCT) is often degraded, which decreases the accuracy of subsequent motion modeling. One of the promising methods is the simultaneous motion estimation and image reconstruction (SMEIR) approach. The objective of this work is to enhance the computational speed of the SMEIR algorithm using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the tetrahedral mesh based on the features of a reference phase 4D-CBCT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. After the mesh generation, the updated motion model and other phases of 4D-CBCT can be obtained by matching the 4D-CBCT projection images at each phase with the corresponding forward projections of the deformed reference phase of 4D-CBCT. The entire process of this 4D-CBCT reconstruction method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its tremendous parallel computing ability. Results: A 4D XCAT digital phantom was used to test the proposed mesh-based image reconstruction algorithm. The image Result shows both bone structures and inside of the lung are well-preserved and the tumor position can be well captured. Compared to the previous voxel-based CPU implementation of SMEIR, the proposed method is about 157 times faster for reconstructing a 10 -phase 4D-CBCT with dimension 256×256×150. Conclusion: The GPU-based parallel 4D CBCT reconstruction method uses the feature-based mesh for estimating motion model and demonstrates equivalent image Result with previous voxel-based SMEIR approach, with significantly improved computational speed

A hybrid biomechanical intensity based deformable image registration of lung 4DCT

International Nuclear Information System (INIS)

Samavati, Navid; Velec, Michael; Brock, Kristy

2015-01-01

Deformable image registration (DIR) has been extensively studied over the past two decades due to its essential role in many image-guided interventions (IGI). IGI demands a highly accurate registration that maintains its accuracy across the entire region of interest. This work evaluates the improvement in accuracy and consistency by refining the results of Morfeus, a biomechanical model-based DIR algorithm.A hybrid DIR algorithm is proposed based on, a biomechanical model–based DIR algorithm and a refinement step based on a B-spline intensity-based algorithm. Inhale and exhale reconstructions of four-dimensional computed tomography (4DCT) lung images from 31 patients were initially registered using the biomechanical DIR by modeling contact surface between the lungs and the chest cavity. The resulting deformations were then refined using the intensity-based algorithm to reduce any residual uncertainties. Important parameters in the intensity-based algorithm, including grid spacing, number of pyramids, and regularization coefficient, were optimized on 10 randomly-chosen patients (out of 31). Target registration error (TRE) was calculated by measuring the Euclidean distance of common anatomical points on both images after registration. For each patient a minimum of 30 points/lung were used.Grid spacing of 8 mm, 5 levels of grid pyramids, and regularization coefficient of 3.0 were found to provide optimal results on 10 randomly chosen patients. Overall the entire patient population (n = 31), the hybrid method resulted in mean ± SD (90th%) TRE of 1.5 ± 1.4 (2.9) mm compared to 3.1 ± 1.9 (5.6) using biomechanical DIR and 2.6 ± 2.5 (6.1) using intensity-based DIR alone.The proposed hybrid biomechanical modeling intensity based algorithm is a promising DIR technique which could be used in various IGI procedures. The current investigation shows the efficacy of this approach for the registration of 4DCT images of the lungs with average accuracy of 1.5�

New 3,4-diaminobenzoic acid Schiff base compounds and their complexes: synthesis, characterization and thermodynamics.

Science.gov (United States)

Mohammadi, Khosro; Niad, Mahmood; Jafari, Tahereh

2014-03-25

Some new tetradentate Schiff base ligands (H3L) were prepared via condensation of 3,4-diaminobenzoic acid with 2-hydroxybenzaldehyde derivatives, such as 3,4-bis((E)-2,4-dihydroxybenzylideneamino)benzoic acid (H3L(1)), 3,4-bis((E)-2-hydroxy-3-methoxybenzylideneamino)benzoic acid (H3L(2)) and 3,4-bis((E)-5-bromo-2-hydroxybenzylideneamino)benzoic acid (H3L(4)). Additionally, a tetradentate Schiff base ligand 3,4-bis((E)-2-hydroxybenzylideneamino)benzoic acid (H3L(3)) and its complexes were synthesized. Their metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) were prepared in good yields from the reaction of the ligands with the corresponding metal acetate. They were characterized based on IR, (1)H NMR, Mass spectroscopy and UV-Vis spectroscopy. Also, the formation constants of the complexes were measured by UV-Vis spectroscopic titration at constant ionic strength 0.1M (NaClO4), at 25 °C in dimethylformamide (DMF) as a solvent. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

926 nm laser operation in Nd:GdNbO4 crystal based on 4F3/2 → 4I9/2 transition

Science.gov (United States)

Yan, Renpeng; Li, Xudong; Yao, Wenming; Shen, Yingjie; Zhou, Zhongxiang; Peng, Fang; Zhang, Qingli; Dou, Renqing; Gao, Jing

2018-05-01

926 nm laser operation in a Nd:GdNbO4 crystal based on quasi-three-level 4F3/2 → 4I9/2 transition is reported, for the first time to our best knowledge. An average output power of 393 mW at 926 nm under 879 nm LD pumping is obtained with a slope efficiency of 33.3% and an optical-to-optical efficiency of 26.0%. The slope efficiency with respect to absorbed pump power is estimated to be 47.7%. Comparison between output characters of 926 nm laser under direct and indirect pumping is conducted. The average output power at 926 nm under 808 nm LD pumping reaches 305 mW with an optical-to-optical efficiency of 16.1%.

SU-E-J-01: 3D Fluoroscopic Image Estimation From Patient-Specific 4DCBCT-Based Motion Models

International Nuclear Information System (INIS)

Dhou, S; Hurwitz, M; Lewis, J; Mishra, P

2014-01-01

Purpose: 3D motion modeling derived from 4DCT images, taken days or weeks before treatment, cannot reliably represent patient anatomy on the day of treatment. We develop a method to generate motion models based on 4DCBCT acquired at the time of treatment, and apply the model to estimate 3D time-varying images (referred to as 3D fluoroscopic images). Methods: Motion models are derived through deformable registration between each 4DCBCT phase, and principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated based on cone-beam projections simulating kV treatment imaging. PCA coefficients are optimized iteratively through comparison of these cone-beam projections and projections estimated based on the motion model. Digital phantoms reproducing ten patient motion trajectories, and a physical phantom with regular and irregular motion derived from measured patient trajectories, are used to evaluate the method in terms of tumor localization, and the global voxel intensity difference compared to ground truth. Results: Experiments included: 1) assuming no anatomic or positioning changes between 4DCT and treatment time; and 2) simulating positioning and tumor baseline shifts at the time of treatment compared to 4DCT acquisition. 4DCBCT were reconstructed from the anatomy as seen at treatment time. In case 1) the tumor localization error and the intensity differences in ten patient were smaller using 4DCT-based motion model, possible due to superior image quality. In case 2) the tumor localization error and intensity differences were 2.85 and 0.15 respectively, using 4DCT-based motion models, and 1.17 and 0.10 using 4DCBCT-based models. 4DCBCT performed better due to its ability to reproduce daily anatomical changes. Conclusion: The study showed an advantage of 4DCBCT-based motion models in the context of 3D fluoroscopic images estimation. Positioning and tumor baseline shift uncertainties were mitigated by the 4DCBCT-based

Synthesis and characterization of Li{sub 4}SiO{sub 4} nano-powders by a water-based sol-gel process

Energy Technology Data Exchange (ETDEWEB)

Wu Xiangwei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Wen Zhaoyin, E-mail: zywen@mail.sic.ac.c [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Xu Xiaogang; Wang Xiuyan; Lin Jiu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

2009-08-01

The water-based sol-gel process for the synthesis of Li{sub 4}SiO{sub 4} nano-powders was reported for the first time. LiOH.H{sub 2}O and aerosil SiO{sub 2} were used as the starting materials with citric acid (C{sub 6}H{sub 8}O{sub 7}.H{sub 2}O) as the chelating agent. Li{sub 4}SiO{sub 4} powders with particle size as small as 100 nm were successfully synthesized at the temperature as low as 675 deg. C. Phase analysis, morphology, sintering behavior of the powders and ionic conductivity of the sintered bodies were investigated systematically. The experimental results showed that the powders obtained by the water-based sol-gel process (SG) possessed excellent sinterability, exhibiting a linear shrinkage of 5.2% while sintered to 900 deg. C, more than 3 times that of the powders obtained by solid state reaction (SSR). The bulk conductivity of the SG sintered bodies was much higher than that of the SSR samples at the same testing temperature.

Synthesis of schiff bases of pyridine-4-carbaldehyde and their antioxidant and DNA binding studies

International Nuclear Information System (INIS)

Shamim, S.; Murtaza, S.; Nazar, M.F.

2016-01-01

A series of Schiff bases of pyridine-4-carbaldehyde with 3-aminobenzoic acid, 2-aminobenzoic acid, 4-aminobenzoic acid, 1,3-phenylenediamine, 1,2-phenylenediamine, 2-aminothiophenol, 4-aminoantipyrene, 2-aminophenol and naphthalene-1-amine was synthesized and compounds were characterized by FTIR, NMR and mass spectrometry. The synthesized compounds were evaluated for their antioxidant and DNA binding interaction studies. DPPH scavenging method was used to evaluate the antioxidant activities of synthesized Schiff bases at six gradually increasing concentrations of 0.5-5mg/ml. 2-((pyridin-4-ylmethylidene)amino)phenol came out to be the most efficient antioxidant at a concentration of 4mg/ml with 74% inhibition of free radicals generated by DPPH. The DNA binding interaction of the synthesized Schiff bases was determined using UV-Vis absorption titration method. Both the hypochromic and hyperchromic effects were observed along the series. The values for the binding constant (K) and free energy change (G) were calculated and most of the Schiff bases have high positive K values which indicate the efficient binding of Schiff bases with DNA. Molecular docking studies as carried out using PatchDock molecular algorithm software also indicated the high values for geometrical shape complementarity score suggesting the stabilities of Schiff bases/DNA complex. Docking studies also suggested the minor groove binding of the Schiff bases with DNA. Drug-likeness of the synthesized compounds was also tested in silico and the results are accordingly discussed. (author)

An Energy Dense-AI-NaBH4-PEMFC Based Power Generator for Unmanned Undersea Vehicles

Science.gov (United States)

2016-03-01

From- To) 03/01/2016 Final 01/28/2013-12/31/2015 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER An Energy-Dense AI-NaBH4- PEMFC Based Power Generator for...combination of polymer electrolyte membrane fuel cell ( PEMFC ) with a compact hydrogen generator util izing AI-NaBH4 composite fuel. The conditions...ANSI Std. Z39.18 FLORIDA SOLAR ENERGY CENTER. Crl’nrmg EnPrgy lnrll’pendrnr£’ An Energy-Dense Al-NaBH4- PEMFC Based Power Generator for Unmanned

Minor actinides transmutation scenario studies with PWRs, FRs and moderated targets

International Nuclear Information System (INIS)

Grouiller, J.P.; Pillon, S.; Saint Jean, C. de; Varaine, F.; Leyval, L.; Vambenepe, G.; Carlier, B.

2003-01-01

Using current technologies, we have demonstrated in this study that it is theoretically possible to obtain different minor actinide transmutation scenarios with a significant gain on the waste radiotoxicity inventory. The handling of objects with Am+Cm entails the significant increase of penetrating radiation sources (neutron and γ) whatever mixed scenario is envisioned; the PWR and FR scenario involving the recycling of Am + Cm in the form of targets results in the lowest flow. In the light of these outcomes, the detailed studies has allowed to design a target sub assembly with a high fission rate (90%) and define a drawing up of reprocessing diagram with the plant head, the minor actinide separation processes (PUREX, DIAMEX and SANEX). Some technological difficulties appear in manipulating curium, principally in manufacturing where the wet process ('sol-gel') is not acquired for (Am+Cm). (author)

Comparison of lung tumor motion measured using a model-based 4DCT technique and a commercial protocol.

Science.gov (United States)

O'Connell, Dylan; Shaverdian, Narek; Kishan, Amar U; Thomas, David H; Dou, Tai H; Lewis, John H; Lamb, James M; Cao, Minsong; Tenn, Stephen; Percy, Lee P; Low, Daniel A

2017-11-11

To compare lung tumor motion measured with a model-based technique to commercial 4-dimensional computed tomography (4DCT) scans and describe a workflow for using model-based 4DCT as a clinical simulation protocol. Twenty patients were imaged using a model-based technique and commercial 4DCT. Tumor motion was measured on each commercial 4DCT dataset and was calculated on model-based datasets for 3 breathing amplitude percentile intervals: 5th to 85th, 5th to 95th, and 0th to 100th. Internal target volumes (ITVs) were defined on the 4DCT and 5th to 85th interval datasets and compared using Dice similarity. Images were evaluated for noise and rated by 2 radiation oncologists for artifacts. Mean differences in tumor motion magnitude between commercial and model-based images were 0.47 ± 3.0, 1.63 ± 3.17, and 5.16 ± 4.90 mm for the 5th to 85th, 5th to 95th, and 0th to 100th amplitude intervals, respectively. Dice coefficients between ITVs defined on commercial and 5th to 85th model-based images had a mean value of 0.77 ± 0.09. Single standard deviation image noise was 11.6 ± 9.6 HU in the liver and 6.8 ± 4.7 HU in the aorta for the model-based images compared with 57.7 ± 30 and 33.7 ± 15.4 for commercial 4DCT. Mean model error within the ITV regions was 1.71 ± 0.81 mm. Model-based images exhibited reduced presence of artifacts at the tumor compared with commercial images. Tumor motion measured with the model-based technique using the 5th to 85th percentile breathing amplitude interval corresponded more closely to commercial 4DCT than the 5th to 95th or 0th to 100th intervals, which showed greater motion on average. The model-based technique tended to display increased tumor motion when breathing amplitude intervals wider than 5th to 85th were used because of the influence of unusually deep inhalations. These results suggest that care must be taken in selecting the appropriate interval during image generation when using model-based 4DCT methods. Copyright © 2017

A data base for thermodynamic modeling of +III actinide solubility in concentrated Na-Cl-SO4-CO3-PO4 electrolytes

International Nuclear Information System (INIS)

Novak, C.F.; Crafts, C.C.; Dhooge, N.J.

1995-01-01

The literature contains thermodynamic parameters for describing the chemical behavior of the following: Am(III) in dilute NaHCO 3 media; Nd(III) in dilute to concentrated Na 2 CO 3 and NaHCO 3 media; Pu(III) in dilute to concentrated NaCl media; Nd(III)/Am(III) in dilute to concentrated Na 2 SO 4 media; and Am(III) in NaH 2 PO 4 media. We have combined this information into a thermodynamic data base for the general +III actinide, An(III), using the analogy for chemical behavior of f-elements in the same oxidation state. This internally consistent data base is based on equilibrium thermodynamics and the specific ion interaction activity coefficient formalism of Pitzer. This data base forms the basis for the prediction of potential Am(III) and Pu(III) dissolved concentrations in the concentrated natural brines associated with the Waste Isolation Pilot Plant (WIPP) in Southeastern New Mexico, USA

Two new 3-D cadmium bromoplumbates: the only example of heterometallic bromoplumbate based on crown [Cd(Pb4O4)Br2] clusters.

Science.gov (United States)

Xiao, Hong; Zhou, Jian; Liu, Xing

2018-04-03

Two new cadmium bromoplumbates [CdPb2Br2L2]n (1, L = ethylene glycol) and [CdPb6Br6L4]n (2) have been solvothermally synthesized and structurally characterized. 1 contains 1-D neutral heterometallic chains [CdPb2Br2L2]n, which are further connected via weak Pb-Br bonds, resulting in a 3-D network structure. The 3-D framework of 2 is constructed by the interconnection of a 2-D neutral layer [CdPb6Br6L4]nvia weak Pb-Br bonds. The [CdPb6Br6L4]n layer is based on the linkages of dimeric [Pb2Br4] units and heterometallic crown [Cd(Pb4O4)Br2] clusters containing a rare eight-membered [Pb4O4] ring. Although a few heterometallic bromoplumbate clusters have been reported, they usually exhibit molecular moieties. 2 represents the only example of 3-D heterometallic bromoplumbate based on the combination of heterometallic crown [Cd(Pb4O4)Br2] clusters and dimeric [Pb2Br4] units. Their optical properties are studied and density functional theory calculations for 1 and 2 have also been performed.

Surfaced-based investigations plan, Volume 4: Yucca Mountain Project

International Nuclear Information System (INIS)

1988-12-01

This document represents a detailed summary of design plans for surface-based investigations to be conducted for site characterization of the Yucca Mountain site. These plans are current as of December 1988. The description of surface-based site characterization activities contained in this document is intended to give all interested parties an understanding of the current plans for site characterization of Yucca Mountain. The maps presented in Volume 4 are products of the Geographic Information System (GIS) being used by the Yucca Mountain Project. The ARC/INFO GIS software, developed by Environmental Systems Research Institute, was used to digitize and process these SBIP maps. The maps were prepared using existing US Geological Survey (USGS) maps as a planimetric base. Roads and other surface features were interpreted from a variety of sources and entered into the GIS. Sources include the USGS maps, 1976 USGS orthophotoquads and aerial photography, 1986 and 1987 aerial photography, surveyed coordinates of field sites, and a combination of various maps, figures, descriptions and approximate coordinates of proposed locations for future activities

Standard Technical Specifications General Electric plants, BWR/4:Bases (Sections 3.4-3.10). Volume 3, Revision 1

International Nuclear Information System (INIS)

1995-04-01

This report documents the results of the combined effort of the NRC and the industry to produce improved Standard Technical Specifications (STS), Revision 1 for General Electric BWR/4 Plants. The changes reflected in Revision 1 resulted from the experience gained from license amendment applications to convert to these improved STS or to adopt partial improvements to existing technical specifications. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and various nuclear power plant licensees, Nuclear Steam Supply System (NSSS) Owners Groups, NSSS vendors, and the Nuclear Energy Institute (NEI). The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. Volume 1 contains the specifications for all chapters and sections of the improved STS. Volume 2 contains he Bases for Chapters 2.0 and 3.0, and Sections 3.1-3.3 of the improved STS. This document, Volume 3, contains the Bases for Sections 3.4-3.10 of the improved STS

Spectroscopic investigation of complexation of Cm(III) und Eu(III) with partitioning-relevant N-donor ligands

International Nuclear Information System (INIS)

Bremer, Antje

2014-01-01

The separation of trivalent actinides and lanthanides is an essential part of the development of improved nuclear fuel cycles. Liquid-liquid extraction is an applicable technique to achieve this separation. Due to the chemical similarity and the almost identical ionic radii of trivalent actinides and lanthanides this separation is, however, only feasible with highly selective extracting agents. It has been proven that molecules with soft sulphur or nitrogen donor atoms have a higher affinity for trivalent actinides. In the present work, the complexation of Cm(III) and Eu(III) with N-donor ligands relevant for partitioning has been studied by time-resolved laser fluorescence spectroscopy (TRLFS). This work aims at a better understanding of the molecular reason of the selectivity of these ligands. In this context, enormous effort has been and is still put into detailed investigations on BTP and BTBP ligands, which are the most successful N-donor ligands for the selective extraction of trivalent actinides, to date. Additionally, the complexation and extraction behavior of molecules which are structurally related to these ligands is studied. The ligand C5-BPP (2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine) where the triazine rings of the aromatic backbone of the BTP ligands have been replaced by pyrazole rings is one of these molecules. Laser fluorescence spectroscopic investigation of the complexation of Cm(III) with this ligand revealed stepwise formation of three (Cm(C5-BPP) n ) 3+ complexes (n = 1 - 3). The stability constant of the 1:3 complex was determined (log β 3 = 14.8 ± 0.4). Extraction experiments have shown that, in contrast to BTP and BTBP ligands, C5-BPP needs an additional lipophilic anion source such as a 2-bromocarboxylic acid to selectively extract trivalent actinides from nitric acid solutions. The comparison of the stability constant of the (Cm(C5-BPP) 3 ) 3+ complex with the stability constant of the (Cm(nPr-BTP) 3 ) 3+ complex

2nd international workshop on graphene and C3N4-based photocatalysts

Science.gov (United States)

Yu, Jiaguo; Jaroniec, Mietek

2018-02-01

Since 2009 graphene and C3N4-based photocatalysts have attracted a lot of attention in scientific and engineering communities because of their applications in photocatalysis. Graphene and C3N4-based photocatalysis was the main theme of the 2nd International Workshop on Graphene and C3N4-based Photocatalysts (IWGCP2) held at the Wuhan University of Technology, Wuhan, China on March 24-27, 2017. The IWGCP2 workshop was jointly organized by Wuhan University of Technology, Jianghan University, Changsha University and Kent State University, and was supported by the National Natural Science Foundation of China (NSFC), Wuhan University of Technology, Jianghan University, Changsha University, Beijing Perfectlight, ThermoFisher, LumaSense Technologies, Anhui Kemi, Zhenjiang Silver Jewelry, Instytut Fotonowy (Poland) and others. More than 240 colleagues from four continents (Asia, America, Australia and Europe) participated in this workshop, and presented 6 plenary lectures, 12 keynote lectures, 14 invited lectures, 5 oral lectures and 113 posters. A tradition of this meeting is the poster competition, which resulted in selecting 10 best posters.

Dose optimization in radiotherapy patients for IMRT based on 4D-CBCT

International Nuclear Information System (INIS)

Alfonso, R.; Castillo, D.; Ascensión, Y.; Linares, H.; García, F.; Argota, R.

2015-01-01

The use of tomographic systems based on conical photon beams kVp (kV-CBCT) to verify the accuracy of the positioning of patients in external radiotherapy treatments has expanded in recent years, with increasing availability of linear accelerators systems for image guided radiation therapy (IGRT) based kV-CBCT systems, incorporated into the gantry of the equipment. Several studies have evaluated the collateral doses received by patients using these positioning systems for radiotherapy (RT). Recently, the firm Elekta has developed a solution to manage the effects of respiratory movements and reduce internal margins that affect the planning target volume (Symmetry TM ), which is based on the acquisition of dynamic tomographic studies (4D- CBCT), making it possible to estimate the average white temporal position in each treatment, without using methods triggered or ‘tracking’. These 4D studies however require a greater number of images per gantry angle, potentially involves a higher dose administered to patients, besides the actual dose treatment beam. The present study investigated a methodology to assess dose rates 4DCBCT (4D-CBDI) using dosimetric instrumentation and phantoms as those typically available in radiotherapy departments. The doses received by different techniques are compared using as criteria of merit image quality and overall geometric accuracy achieved in positioning and internal margins. The results show that it is possible to reduce the administered to patients in studies of CBCT static and dynamic, without significantly affecting the objectives of the same in terms of geometric accuracy dose. [es

Oil-soluble and water-soluble BTPhens and their europium complexes in octanol/water solutions: interface crossing studied by MD and PMF simulations.

Science.gov (United States)

Benay, G; Wipff, G

2013-01-31

Bistriazinyl-phenantroline "BTPhen" ligands L display the remarkable feature to complex trivalent lanthanide and actinide ions, with a marked selectivity for the latter. We report on molecular dynamics studies of tetrasubstituted X(4)BTPhens: L(4+) (X = (+)Et(3)NCH(2)-), L(4-) (X = (-)SO(3)Ph-), and L(0) (X = CyMe(4)) and their complexes with Eu(III) in binary octanol/water solutions. Changes in free energies upon interface crossing are also calculated for typical solutes by potential of mean force PMF simulations. The ligands and their complexes partition, as expected, to either the aqueous or the oil phase, depending on the "solubilizing" group X. Furthermore, most of them are found to be surface active. The water-soluble L(4+) and L(4-) ligands and their (L)Eu(NO(3))(3) complexes adsorb at the aqueous side of the interface, more with L(4-) than with L(4+). The oil soluble ligand L(0) is not surface active in its endo-endo form but adsorbs on the oil side of the interface in its most polar endo-exo form, as well as in its protonated L(0)H(+) and complexed (L(0))Eu(NO(3))(3) states. Furthermore, comparing PMFs of the Eu(III) complexes with and without nitric acid shows that acidifying the aqueous phase has different effects, depending on the ligand charge. In particular, acid promotes the Eu(III) extraction by L(0) via the (L(0))(2)Eu(NO(3))(2+) complex, as observed experimentally. Overall, the results point to the importance of interfacial adsorption for the liquid-liquid extraction of trivalent lanthanide and actinide cations by BTPhens and analogues.

Performance limitations in thieno[3,4-c]pyrrole-4,6-dione-based polymer:ITIC solar cells

KAUST Repository

Yang, Fan

2017-08-15

We report a systematic study of the efficiency limitations of non-fullerene organic solar cells that exhibit a small energy loss (Eloss) between the polymer donor and the non-fullerene acceptor. To clarify the impact of Eloss on the performance of the solar cells, three thieno[3,4-c]pyrrole-4,6-dione-based conjugated polymers (PTPD3T, PTPD2T, and PTPDBDT) are employed as the electron donor, which all have complementary absorption spectra compared with the ITIC acceptor. The corresponding photovoltaic devices show that low Eloss (0.54 eV) in PTPDBDT:ITIC leads to a high open-circuit voltage (Voc) of 1.05 V, but also to a small quantum efficiency, and in turn photocurrent. The high Voc or small energy loss in the PTPDBDT-based solar cells is a consequence of less non-radiative recombination, whereas the low quantum efficiency is attributed to the unfavorable micro-phase separation, as confirmed by the steady-state and time-resolved photoluminescence experiments, grazing-incidence wide-angle X-ray scattering, and resonant soft X-ray scattering (R-SoXS) measurements. We conclude that to achieve high performance non-fullerene solar cells, it is essential to realize a large Voc with small Eloss while simultaneously maintaining a high quantum efficiency by manipulating the molecular interaction in the bulk-heterojunction.

Performance limitations in thieno[3,4-c]pyrrole-4,6-dione-based polymer:ITIC solar cells

KAUST Repository

Yang, Fan; Qian, Deping; Balawi, Ahmed Hesham; Wu, Yang; Ma, Wei; Laquai, Fré dé ric; Tang, Zheng; Zhang, Fengling; Li, Weiwei

2017-01-01

We report a systematic study of the efficiency limitations of non-fullerene organic solar cells that exhibit a small energy loss (Eloss) between the polymer donor and the non-fullerene acceptor. To clarify the impact of Eloss on the performance of the solar cells, three thieno[3,4-c]pyrrole-4,6-dione-based conjugated polymers (PTPD3T, PTPD2T, and PTPDBDT) are employed as the electron donor, which all have complementary absorption spectra compared with the ITIC acceptor. The corresponding photovoltaic devices show that low Eloss (0.54 eV) in PTPDBDT:ITIC leads to a high open-circuit voltage (Voc) of 1.05 V, but also to a small quantum efficiency, and in turn photocurrent. The high Voc or small energy loss in the PTPDBDT-based solar cells is a consequence of less non-radiative recombination, whereas the low quantum efficiency is attributed to the unfavorable micro-phase separation, as confirmed by the steady-state and time-resolved photoluminescence experiments, grazing-incidence wide-angle X-ray scattering, and resonant soft X-ray scattering (R-SoXS) measurements. We conclude that to achieve high performance non-fullerene solar cells, it is essential to realize a large Voc with small Eloss while simultaneously maintaining a high quantum efficiency by manipulating the molecular interaction in the bulk-heterojunction.

Iterative volume morphing and learning for mobile tumor based on 4DCT.

Science.gov (United States)

Mao, Songan; Wu, Huanmei; Sandison, George; Fang, Shiaofen

2017-02-21

During image-guided cancer radiation treatment, three-dimensional (3D) tumor volumetric information is important for treatment success. However, it is typically not feasible to image a patient's 3D tumor continuously in real time during treatment due to concern over excessive patient radiation dose. We present a new iterative morphing algorithm to predict the real-time 3D tumor volume based on time-resolved computed tomography (4DCT) acquired before treatment. An offline iterative learning process has been designed to derive a target volumetric deformation function from one breathing phase to another. Real-time volumetric prediction is performed to derive the target 3D volume during treatment delivery. The proposed iterative deformable approach for tumor volume morphing and prediction based on 4DCT is innovative because it makes three major contributions: (1) a novel approach to landmark selection on 3D tumor surfaces using a minimum bounding box; (2) an iterative morphing algorithm to generate the 3D tumor volume using mapped landmarks; and (3) an online tumor volume prediction strategy based on previously trained deformation functions utilizing 4DCT. The experimental performance showed that the maximum morphing deviations are 0.27% and 1.25% for original patient data and artificially generated data, which is promising. This newly developed algorithm and implementation will have important applications for treatment planning, dose calculation and treatment validation in cancer radiation treatment.

Preparation of Affinity Column Based on Zr4+ Ion for Phosphoproteins Isolation

International Nuclear Information System (INIS)

Lee, Seon Mi; Bae, In Ae; Park, Jung Hyen; Kim, Tae Dong; Choi, Seong Ho

2009-01-01

This paper has described about preparation of Zr 4+ affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr 4+ ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr 4+ -immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr 4+ affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr 4+ affinity polymeric microsphere by liquid chromatography. This Zr 4+ affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography

SVM-Based Dynamic Reconfiguration CPS for Manufacturing System in Industry 4.0

Directory of Open Access Journals (Sweden)

Hyun-Jun Shin

2018-01-01

Full Text Available CPS is potential application in various fields, such as medical, healthcare, energy, transportation, and defense, as well as Industry 4.0 in Germany. Although studies on the equipment aging and prediction of problem have been done by combining CPS with Industry 4.0, such studies were based on small numbers and majority of the papers focused primarily on CPS methodology. Therefore, it is necessary to study active self-protection to enable self-management functions, such as self-healing by applying CPS in shop-floor. In this paper, we have proposed modeling of shop-floor and a dynamic reconfigurable CPS scheme that can predict the occurrence of anomalies and self-protection in the model. For this purpose, SVM was used as a machine learning technology and it was possible to restrain overloading in manufacturing process. In addition, we design CPS framework based on machine learning for Industry 4.0, simulate it, and perform. Simulation results show the simulation model autonomously detects the abnormal situation and it is dynamically reconfigured through self-healing.

Evaluation of calix[4]arene tethered Schiff bases for anion recognition

International Nuclear Information System (INIS)

Chawla, H.M.; Munjal, Priyanka

2016-01-01

Two calix[4]arene tethered Schiff base derivatives (L1 and L2) have been synthesized and their ion recognition capability has been evaluated through NMR, UV–vis and fluorescence spectroscopy. L1 interacts with cyanide ions very selectively to usher a significant change in color and fluorescence intensity. On the other hand L2 does not show selectivity for anion sensing despite having the same functional groups as those present in L1. The differential observations may be attributed to plausible stereo control of anion recognition and tautomerization in the synthesized Schiff base derivatives.

Evaluation of calix[4]arene tethered Schiff bases for anion recognition

Energy Technology Data Exchange (ETDEWEB)

Chawla, H.M., E-mail: hmchawla@chemistry.iitd.ac.in; Munjal, Priyanka

2016-11-15

Two calix[4]arene tethered Schiff base derivatives (L1 and L2) have been synthesized and their ion recognition capability has been evaluated through NMR, UV–vis and fluorescence spectroscopy. L1 interacts with cyanide ions very selectively to usher a significant change in color and fluorescence intensity. On the other hand L2 does not show selectivity for anion sensing despite having the same functional groups as those present in L1. The differential observations may be attributed to plausible stereo control of anion recognition and tautomerization in the synthesized Schiff base derivatives.

Synthesis of palm-based polyurethane-LiClO{sub 4} via prepolymerization

Energy Technology Data Exchange (ETDEWEB)

Sien, Jason Wong Chee [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia); School of Biosciences, Taylor’s University, Subang Jaya (Malaysia); Badri, Khairiah Haji [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia); Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia); Su’ait, Mohd Sukor [Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia); Solar Energy Research Institute Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia); Hassan, Nurul Izzati [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi (Malaysia)

2015-09-25

Palm-based polyurethane (pPU) with varying lithium salt (LiClO{sub 4}) content was synthesized. Higher loading percentage of LiClO{sub 4} in the pPU led to the inhibition of prepolymerization process from taking place. Hydrogen bonded C=O was detected in the FTIR spectrum indicating the hydrogen bonding between the urethane bonds. Ordered complexed C=O was observed in the FTIR spectrum confirming the complex formation between urethane bond and Li{sup +} ion. DSC thermogram showed the increase in the LiClO{sub 4} content could increase the glass transition temperature. SEM micrographs exhibited that more bubbles were formed when the LiClO{sub 4} increased from 10 to 30wt% indicating the reaction between free isocyanate groups with moisture presence in the salt due to the hygroscopic properties of LiClO{sub 4}.

Design and development of mobile Email system based on brew and IMAP4

International Nuclear Information System (INIS)

Chen Liangchen; Liu Shuzhen; Yan Xiaofei; Sun Gongxing

2007-01-01

In order to achieve IMAP4 support agreement in the mobile e-mail client application on the smart phone, using the Qualcomm introduced wireless devices designed for the BREW platform. Research on the BREW platform mobile and IMAP4 protocol, design and implement the 3G technology standard smart phone e-mail client based on the BREW platform. (authors)

On the interdiffusion in multilayered silicide coatings for the vanadium-based alloy V-4Cr-4Ti

Energy Technology Data Exchange (ETDEWEB)

Chaia, N., E-mail: nabil.chaia@usp.br [Escola de Engenharia de Lorena, Universidade de São Paulo, Pólo Urbo-Industrial Gleba AI-6, 12602-810 Lorena, SP (Brazil); Portebois, L., E-mail: leo.portebois@univ-lorraine.fr [Université de Lorraine, Institut Jean Lamour, UMR7198, Boulevard des Aiguillettes, BP70239, 54506 Vandoeuvre-lès-Nancy, Cedex (France); Mathieu, S., E-mail: stephane.mathieu@univ-lorraine.fr [Université de Lorraine, Institut Jean Lamour, UMR7198, Boulevard des Aiguillettes, BP70239, 54506 Vandoeuvre-lès-Nancy, Cedex (France); David, N., E-mail: nicolas.david@univ-lorraine.fr [Université de Lorraine, Institut Jean Lamour, UMR7198, Boulevard des Aiguillettes, BP70239, 54506 Vandoeuvre-lès-Nancy, Cedex (France); Vilasi, M., E-mail: michel.vilasi@univ-lorraine.fr [Université de Lorraine, Institut Jean Lamour, UMR7198, Boulevard des Aiguillettes, BP70239, 54506 Vandoeuvre-lès-Nancy, Cedex (France)

2017-02-15

To provide protection against corrosion at high temperatures, silicide diffusion coatings were developed for the V-4Cr-4Ti alloy, which can be used as the fuel cladding in next-generation sodium-cooled fast breeder reactors. The multilayered coatings were prepared by halide-activated pack cementation using MgF{sub 2} as the transport agent and pure silicon (high activity) as the master alloy. Coated pure vanadium and coated V-4Cr-4Ti alloy were studied and compared as substrates. In both cases, the growth of the silicide layers (V{sub 3}Si, V{sub 5}Si{sub 3}, V{sub 6}Si{sub 5} and VSi{sub 2}) was controlled exclusively by solid-state diffusion, and the growth kinetics followed a parabolic law. Wagner's analysis was adopted to calculate the integrated diffusion coefficients for all silicides. The estimated values of the integrated diffusion coefficients range from approximately 10{sup −9} to 10{sup −13} cm{sup 2} s{sup −1}. Then, a diffusion-based numerical approach was used to evaluate the growth and consumption of the layers when the coated substrates were exposed at critical temperatures. The estimated lifetimes of the upper VSi{sub 2} layer were 400 h and 280 h for pure vanadium and the V-4Cr-4Ti alloy, respectively. The result from the numeric simulation was in good agreement with the layer thicknesses measured after aging the coated samples at 1150 °C under vacuum. - Highlights: • The pack cementation technique is implemented to study interdiffusion in V/Si and V-4Cr-4Ti/Si couples. • Interdiffusion coefficients of vanadium silicides were experimentally determined within the range 1100–1250 °C. • For either V/Si or V-4Cr-4Ti/Si couples, the VSi{sub 2} layer has the highest growth rate. • The Cr and Ti alloying elements mainly modified the V{sub 5}Si{sub 3} and V{sub 6}Si{sub 5} growth rate. • Numerical simulation allows for a confident assessment of the VSi{sub 2} coating lifetime on V-4Cr-4Ti.

Some peculiarities of inflorescences morphogenesis in Brexia (Celastraceae

Directory of Open Access Journals (Sweden)

Ivan A. Savinov

2013-04-01

Full Text Available Comparative analysis of inflorescences structure for 6 species of the Brexia(according to the last revision by Schatz & Lowry II (2004 is conducted. For one species, B. madagascariensis, the shoots growth and development, inflorescence morphogenesis details are studied. It is determined inflorescences of Brexiaspecies (have described in literature as cymes, pseudo-umbellate, corymbiform, sessile in fascicles; and including for some species cauliflory presents a different variations of ancestral form transformation – dichasial system (closed thyrse. Apparently, presence of a big bracts may be consider as ancestral, plesiomorphic character for the genus; and derivate ones – reduction of bracts and presence of minute bracteoles in pedicel basis only. Inflorescences of Brexiain typically may be considered as bracteous. Process of reduction the number of clusters and separate flowers is accompanied by different variations of their transformations.

TU-AB-202-05: GPU-Based 4D Deformable Image Registration Using Adaptive Tetrahedral Mesh Modeling

International Nuclear Information System (INIS)

Zhong, Z; Zhuang, L; Gu, X; Wang, J; Chen, H; Zhen, X

2016-01-01

Purpose: Deformable image registration (DIR) has been employed today as an automated and effective segmentation method to transfer tumor or organ contours from the planning image to daily images, instead of manual segmentation. However, the computational time and accuracy of current DIR approaches are still insufficient for online adaptive radiation therapy (ART), which requires real-time and high-quality image segmentation, especially in a large datasets of 4D-CT images. The objective of this work is to propose a new DIR algorithm, with fast computational speed and high accuracy, by using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the adaptive tetrahedral mesh based on the image features of a reference phase of 4D-CT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. Subsequently, the deformation vector fields (DVF) and other phases of 4D-CT can be obtained by matching each phase of the target 4D-CT images with the corresponding deformed reference phase. The proposed 4D DIR method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its parallel computing ability. Results: A 4D NCAT digital phantom was used to test the efficiency and accuracy of our method. Both the image and DVF results show that the fine structures and shapes of lung are well preserved, and the tumor position is well captured, i.e., 3D distance error is 1.14 mm. Compared to the previous voxel-based CPU implementation of DIR, such as demons, the proposed method is about 160x faster for registering a 10-phase 4D-CT with a phase dimension of 256×256×150. Conclusion: The proposed 4D DIR method uses feature-based mesh and GPU-based parallelism, which demonstrates the capability to compute both high-quality image and motion results, with significant improvement on the computational speed.

TU-AB-202-05: GPU-Based 4D Deformable Image Registration Using Adaptive Tetrahedral Mesh Modeling

Energy Technology Data Exchange (ETDEWEB)

Zhong, Z; Zhuang, L [Wayne State University, Detroit, MI (United States); Gu, X; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States); Chen, H; Zhen, X [Southern Medical University, Guangzhou, Guangdong (China)

2016-06-15

Purpose: Deformable image registration (DIR) has been employed today as an automated and effective segmentation method to transfer tumor or organ contours from the planning image to daily images, instead of manual segmentation. However, the computational time and accuracy of current DIR approaches are still insufficient for online adaptive radiation therapy (ART), which requires real-time and high-quality image segmentation, especially in a large datasets of 4D-CT images. The objective of this work is to propose a new DIR algorithm, with fast computational speed and high accuracy, by using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the adaptive tetrahedral mesh based on the image features of a reference phase of 4D-CT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. Subsequently, the deformation vector fields (DVF) and other phases of 4D-CT can be obtained by matching each phase of the target 4D-CT images with the corresponding deformed reference phase. The proposed 4D DIR method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its parallel computing ability. Results: A 4D NCAT digital phantom was used to test the efficiency and accuracy of our method. Both the image and DVF results show that the fine structures and shapes of lung are well preserved, and the tumor position is well captured, i.e., 3D distance error is 1.14 mm. Compared to the previous voxel-based CPU implementation of DIR, such as demons, the proposed method is about 160x faster for registering a 10-phase 4D-CT with a phase dimension of 256×256×150. Conclusion: The proposed 4D DIR method uses feature-based mesh and GPU-based parallelism, which demonstrates the capability to compute both high-quality image and motion results, with significant improvement on the computational speed.

Discovery of a novel, CNS penetrant M4 PAM chemotype based on a 6-fluoro-4-(piperidin-1-yl)quinoline-3-carbonitrile core.

Science.gov (United States)

Bewley, Blake R; Spearing, Paul K; Weiner, Rebecca L; Luscombe, Vincent B; Zhan, Xiaoyan; Chang, Sichen; Cho, Hyekyung P; Rodriguez, Alice L; Niswender, Colleen M; Conn, P Jeffrey; Bridges, Thomas M; Engers, Darren W; Lindsley, Craig W

2017-09-15

This Letter details the discovery and subsequent optimization of a novel M 4 PAM scaffold based on an 6-fluoro-4-(piperidin-1-yl)quinoline-3-carbonitrile core, which represents a distinct departure from the classical M 4 PAM chemotypes. Optimized compounds in this series demonstrated improved M 4 PAM potency on both human and rat M 4 (4 to 5-fold relative to HTS hit), and displayed attractive physicochemical and DMPK profiles, including good CNS penetration (rat brain:plasma K p =5.3, K p,uu =2.4; MDCK-MDR1 (P-gp) ER=1.1). Copyright © 2017 Elsevier Ltd. All rights reserved.

An Empirical Study on Washback Effects of the Internet-Based College English Test Band 4 in China

Science.gov (United States)

Wang, Chao; Yan, Jiaolan; Liu, Bao

2014-01-01

Based on Bailey's washback model, in respect of participants, process and products, the present empirical study was conducted to find the actual washback effects of the internet-based College English Test Band 4 (IB CET-4). The methods adopted are questionnaires, class observation, interview and the analysis of both the CET-4 teaching and testing…

Gas Permeation Properties of Soluble Aromatic Polyimides Based on 4-Fluoro-4,4'-Diaminotriphenylmethane

Directory of Open Access Journals (Sweden)

Diego Guzmán-Lucero

2015-04-01

Full Text Available A series of new organic polyimides were synthesized from 4-fluoro-4'4"-diaminotriphenylmethane and four different aromatic dianhydrides through a one-step, high-temperature, direct polycondensation in m-cresol at 180–200 °C, resulting in the formation of high-molecular-weight polyimides (inherent viscosities ~ 1.0–1.3 dL/g. All the resulting polyimides exhibited good thermal stability with initial decomposition temperatures above 434 °C, glass-transition temperatures between 285 and 316 °C, and good solubility in polar aprotic solvents. Wide-angle X-ray scattering data indicated that the polyimides were amorphous. Dense membranes were prepared by solution casting and solvent evaporation to evaluate their gas transport properties (permeability, diffusivity, and solubility coefficients toward pure hydrogen, helium, oxygen, nitrogen, methane, and carbon dioxide gases. In general, the gas permeability was increased as both the fractional free volume and d-spacing were also increased. A good combination of permeability and selectivity was promoted efficiently by the bulky hexafluoroisopropylidene and 4-fluoro-phenyl groups introduced into the polyimides. The results indicate that the gas transport properties of these films depend on both the structure of the anhydride moiety, which controls the intrinsic intramolecular rigidity, and the 4-fluoro-phenyl pendant group, which disrupts the intermolecular packing.

Maintenance of Certification Part 4 Credit and recruitment for practice-based research.

Science.gov (United States)

Gorzkowski, Julie A; Klein, Jonathan D; Harris, Donna L; Kaseeska, Kristen R; Whitmore Shaefer, Regina M; Bocian, Alison B; Davis, James B; Gotlieb, Edward M; Wasserman, Richard C

2014-10-01

Competing priorities in pediatric practice have created challenges for practice-based research. To increase recruitment success, researchers must design studies that provide added value to participants. This study evaluates recruitment of pediatricians into a study, before and after the development and addition of a quality improvement (QI) curriculum approved for American Board of Pediatrics Maintenance of Certification (MOC) Part 4 Credit as an enrollment incentive. Researchers implemented multiple outreach methods to enroll pediatric practices over 28 months. Field note review revealed that many physicians declined enrollment, stating that they prioritized MOC Part 4 projects over research studies. A QI curriculum meeting standards for MOC Part 4 Credit was developed and added to the study protocol as an enrollment incentive. Enrollment rates and characteristics of practitioners enrolled pre- and post-MOC were compared. Pre-MOC enrollment contributed 48% of practices in 22 months; post-MOC enrollment contributed 49% of practices in 6 months. An average of 3.5 practices enrolled per month pre-MOC, compared with 13.1 per month post-MOC (P recruitment success and increased enrollment of pediatricians working in underserved areas. Including QI initiatives meeting MOC Part 4 criteria in practice-based research protocols may enhance participation and aid in recruiting diverse practice and patient populations. Copyright © 2014 by the American Academy of Pediatrics.

An electrochemical lipopolysaccharide sensor based on an immobilized Toll-Like Receptor-4.

Science.gov (United States)

Mayall, R M; Renaud-Young, M; Chan, N W C; Birss, V I

2017-01-15

Infections affect millions of people each year and yet methods to ascertain their cause can take more than 24h to be effective. This delay between the presentation with symptoms and the ability to make an informed decision about treatment can have adverse consequences, including death in severe cases. Additionally, pathogen identification is a concern for public safety amid the growing threat of bioterrorism. Developing a detection system based on the immune system offers the advantage of broad specificity, while still remaining pertinent to human health. In this work, human Toll-Like Receptor-4 (TLR-4), a protein responsible for detecting lipopolysaccharide (LPS) of Gram-negative bacteria, was immobilized on both a large area and micro gold electrode via the tethering interaction of a modified Self-Assembled Monolayer (mSAM). In response to varying concentrations of its target, the protein-electrode combination showed a logarithmically proportional increased resistance to charge transfer from a solution-based redox probe, due to the formation of TLR-4 protein dimers. It also demonstrated excellent sensitivity to trace levels of Gram-negative bacteria, while remaining insensitive to both Gram-positive and viral challenges. Further characterization of our mSAM revealed that maintaining the appropriate receptor orientation on the electrode surface, mimicking TLR-4's role in a cellular context, was essential in producing a responsive sensor. Copyright © 2016 Elsevier B.V. All rights reserved.

CAD-based automatic modeling method for Geant4 geometry model through MCAM

International Nuclear Information System (INIS)

Wang, D.; Nie, F.; Wang, G.; Long, P.; LV, Z.

2013-01-01

The full text of publication follows. Geant4 is a widely used Monte Carlo transport simulation package. Before calculating using Geant4, the calculation model need be established which could be described by using Geometry Description Markup Language (GDML) or C++ language. However, it is time-consuming and error-prone to manually describe the models by GDML. Automatic modeling methods have been developed recently, but there are some problems that exist in most present modeling programs, specially some of them were not accurate or adapted to specifically CAD format. To convert the GDML format models to CAD format accurately, a Geant4 Computer Aided Design (CAD) based modeling method was developed for automatically converting complex CAD geometry model into GDML geometry model. The essence of this method was dealing with CAD model represented with boundary representation (B-REP) and GDML model represented with constructive solid geometry (CSG). At first, CAD model was decomposed to several simple solids which had only one close shell. And then the simple solid was decomposed to convex shell set. Then corresponding GDML convex basic solids were generated by the boundary surfaces getting from the topological characteristic of a convex shell. After the generation of these solids, GDML model was accomplished with series boolean operations. This method was adopted in CAD/Image-based Automatic Modeling Program for Neutronics and Radiation Transport (MCAM), and tested with several models including the examples in Geant4 install package. The results showed that this method could convert standard CAD model accurately, and can be used for Geant4 automatic modeling. (authors)

Synthesis, Characterization, and Biological Activity of Novel Schiff and Mannich Bases of 4-Amino-3-(N-phthalimidomethyl-1,2,4-triazole-5-thione

Directory of Open Access Journals (Sweden)

Uzma Yunus

2013-01-01

Full Text Available The present work describes the syntheses and antimicrobial activity studies of a series of novel Schiff bases (4a–4i and their Mannich bases (5a–5h starting from 4-amino-3-(N-phthalimido-methyl-1,2,4-triazole-5-thione (3. All the synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR, and MS. All the synthesized compounds were screened for four Gram-negative strains, one Gram-positive strain of bacteria, and one diploid fungal strain. In general the antimicrobial activity increased remarkably on the introduction of azomethine functionality in parent triazole (3. The antimicrobial activity further improved when morpholine group was added to them except for Enterobacter cloacae, where loss of activity was observed. The results are promising and show that the fine tuning of the structures (5a, 5b, 5e, 5f, and 5h can lead to some new antimicrobial compounds.

Synthesis and luminescence properties of novel 4-(N-carbazole methyl) benzoyl hydrazone Schiff bases

International Nuclear Information System (INIS)

Guo Dongcai; Wu Panliang; Tan Hui; Xia Long; Zhou Wenhui

2011-01-01

4-(N-carbazole methyl) benzoyl hydrazine was synthesized on the basis of carbazole, and then nine novel carbazolyl acylhydrazone Schiff bases were synthesized by the condensation reaction between 4-(N-carbazole methyl) benzoyl hydrazine and the substituted benzaldehydes. The relationships between the substituted group types and the UV fluorescence spectral properties, as well as the fluorescence quantum yields of the title Schiff bases were also investigated. The results show that the introduction of both the donating and accepting electron groups causes various grade redshifts of the fluorescence characteristic emission peak of the title Schiff bases to occur.The fluorescence quantum yields of the title Schiff bases with the donating group are increased, and the highest fluorescence quantum yield is up to 0.703. - Highlights: → Nine novel Schiff bases have been designed and synthesized. → Introduction of the donating electron groups causes various grade red shifts of the fluorescence characteristic emission peak and the UV characteristic absorption peak of the synthesized Schiff bases. → Introduction of the donating electron groups causes the fluorescence quantum yields to be increased considerably. →Introduction of the accepting electron groups causes the fluorescence intensity and quantum yield of the synthesized Schiff bases to be reduced. → Fluorescence quantum yield of o-hydroxyl-substituted Schiff base is up to 0.703; this Schiff base is expected to be used as hole transport optical material.

Developing Critical Thinking of Middle School Students using Problem Based Learning 4 Core Areas (PBL4C) Model

Science.gov (United States)

Haridza, R.; E Irving, K.

2017-02-01

Traditional methods such as rote learning and memorization in teaching science create passive students in science classrooms. The impact of this continuous action for many decades is inactive learners who cannot develop higher order thinking skills. Based on the performance test, students’ critical thinking skill in Public Middle School 3 Pontianak was in low level although their achievement score were higher than school standards. The purpose of this study is to develop critical thinking skills of middle school students using Problem Based Learning 4 Core Areas (PBL4C). The design of this research is classroom action research with two cycles. Data has been collected using observation checklist, rating scale, self and peer assessment. Research findings reveal that students experience development from 11.11% to 88.45% in identifying the problem correctly, 37.03% to 76.92% for sub skills distinguish knowledge and opinion, 18.51% to 65.38% for sub skills providing possible solution, 22.22% to 69.23% for sub skills making decision, and 11.11% to 69.23% for sub skills identifying the impact of the implementation of their solution. In conclusion, the findings indicate that development of students’ critical thinking skills occurs when PBL4C model applied in science classroom. These findings suggest that teachers should act as facilitator in a classroom as well as should provide meaningful learning resources that can benefit students’ critical thinking skills. On the other hand, students should practice constantly to offer a sharp, accurate and appropriate solution.

Floral ontogeny in legume genera Petalostylis, Labichea, and Dialium (Caesalpinioideae: Cassieae), a series in floral reduction.

Science.gov (United States)

Tucker, S

1998-02-01

Floral ontogeny of taxa of two subtribes (Labicheinae, Dialiinae) of caesalpinioid tribe Cassieae, characterized by reduced number of floral organs, was compared. All three taxa studied are distichous; Petalostylis labicheoides flowers are solitary in leaf axils, Labichea lanceolata has few-flowered racemes, and Dialium guineense has numerous-flowered cymes. The first sepal primordium in each is initiated abaxially and nonmedianly. Order of organogenesis in Petalostylis is: five sepals bidirectionally, five petals and carpel simultaneously, then five stamens bidirectionally, starting abaxially. The order in Labichea is: five sepals helically (one lagging in time), five petals unidirectionally starting abaxially, the carpel and petals concurrently, then two stamens successively, starting laterally. Order in Dialium is: five sepals bidirectionally, the single petal adaxially, and lastly the carpel and two stamens concurrently. Specializations include (1) reduction of the five sepals to four by fusion in Petalostylis and Labichea; (2) reduction of petal number to one in Dialium; (3) reduction of stamen number to two in Labichea and Dialium, and reduction of functional stamens to three in Petalostylis; and (4) an elaborate, late-developing style in Petalostylis. Floral asymmetry, another specialization, characterizes Labichea, expressed by dissimilar stamens, while the other genera have zygomorphic flowers. Floral ontogenies are compared with other taxa of Cassieae.

A chemical genetic screen for mTOR pathway inhibitors based on 4E-BP-dependent nuclear accumulation of eIF4E.

Science.gov (United States)

Livingstone, Mark; Larsson, Ola; Sukarieh, Rami; Pelletier, Jerry; Sonenberg, Nahum

2009-12-24

The signal transduction pathway wherein mTOR regulates cellular growth and proliferation is an active target for drug discovery. The search for new mTOR inhibitors has recently yielded a handful of promising compounds that hold therapeutic potential. This search has been limited by the lack of a high-throughput assay to monitor the phosphorylation of a direct rapamycin-sensitive mTOR substrate in cells. Here we describe a novel cell-based chemical genetic screen useful for efficiently monitoring mTOR signaling to 4E-BPs in response to stimuli. The screen is based on the nuclear accumulation of eIF4E, which occurs in a 4E-BP-dependent manner specifically upon inhibition of mTOR signaling. Using this assay in a small-scale screen, we have identified several compounds not previously known to inhibit mTOR signaling, demonstrating that this method can be adapted to larger screens. Copyright 2009 Elsevier Ltd. All rights reserved.

Effects of disorder on the intrinsically hole-doped iron-based superconductor KC a2F e4A s4F2 by cobalt substitution

Science.gov (United States)

Ishida, Junichi; Iimura, Soshi; Hosono, Hideo

2017-11-01

In this paper, the effects of cobalt substitution on the transport and electronic properties of the recently discovered iron-based superconductor KC a2F e4A s4F2 , with Tc=33 K , are reported. This material is an unusual superconductor showing intrinsic hole conduction (0.25 holes /F e2 + ). Upon doping of Co, the Tc of KC a2(Fe1-xC ox) 4A s4F2 gradually decreased, and bulk superconductivity disappeared when x ≥0.25 . Conversion of the primary carrier from p type to n type upon Co-doping was clearly confirmed by Hall measurements, and our results are consistent with the change in the calculated Fermi surface. Nevertheless, neither spin density wave (SDW) nor an orthorhombic phase, which are commonly observed for nondoped iron-based superconductors, was observed in the nondoped or electron-doped samples. The electron count in the 3 d orbitals and structural parameters were compared with those of other iron-based superconductors to show that the physical properties can be primarily ascribed to the effects of disorder.

All-Solid-State Lithium-Sulfur Battery based on a nanoconfined LiBH 4 Electrolyte

NARCIS (Netherlands)

Das, Supti; Ngene, Peter; Norby, Poul; Vegge, Tejs; de Jongh, P.E.; Blanchard, Didier

2016-01-01

In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4in mesoporous silica as solid electrolytes. The nano-confined LiBH4has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport

The rheological responds of the superparamagnetic fluid based on Fe{sub 3}O{sub 4} hollow nanospheres

Energy Technology Data Exchange (ETDEWEB)

Ruan, Xiaohui; Pei, Lei; Xuan, Shouhu, E-mail: xuansh@ustc.edu.cn; Yan, Qifan; Gong, Xinglong, E-mail: gongxl@ustc.edu.cn

2017-05-01

In this work, a superparamagnetic fluid based on Fe{sub 3}O{sub 4} hollow nanospheres was developed and the influence of the particle structure on the rheological properties was investigated. The Fe{sub 3}O{sub 4} hollow nanospheres which were prepared by using the hydrothermal method presented the superparamagnetic characteristic, and the magnetic fluid thereof showed well magnetorheological (MR) effect. The stable magnetic fluid had a high yield stress even at low shear rate and its maximal yield stress was dramatically influenced by the measurement gap. In comparison to the Fe{sub 3}O{sub 4} nanoparticles based magnetic fluid (MF), the Fe{sub 3}O{sub 4} hollow nanospheres based MF exhibited better MR effect and higher stability since the unique hollow nanostructure. The shear stress of the hollow nanospheres is about 1.85 times larger than the nanoparticles based MF because it formed stronger chains structure under applying a magnetic field. To further investigate the enhancing mechanism, a molecule dynamic simulation was conducted to analyze the shear stress and the structure evolution of the Fe{sub 3}O{sub 4} hollow nanospheres based MF and the simulation matched well with the experimental results. - Highlights: • A superparamagnetic fluid based on Fe{sub 3}O{sub 4} hollow nanospheres was investigated. • The stable magnetic fluid had a high yield stress even at low shear rate. • The shear stress of the hollow nanospheres is large. • A molecule dynamic simulation was conducted to analyze the shear stress.

Healthcare4VideoStorm: Making Smart Decisions Based on Storm Metrics.

Science.gov (United States)

Zhang, Weishan; Duan, Pengcheng; Chen, Xiufeng; Lu, Qinghua

2016-04-23

Storm-based stream processing is widely used for real-time large-scale distributed processing. Knowing the run-time status and ensuring performance is critical to providing expected dependability for some applications, e.g., continuous video processing for security surveillance. The existing scheduling strategies' granularity is too coarse to have good performance, and mainly considers network resources without computing resources while scheduling. In this paper, we propose Healthcare4Storm, a framework that finds Storm insights based on Storm metrics to gain knowledge from the health status of an application, finally ending up with smart scheduling decisions. It takes into account both network and computing resources and conducts scheduling at a fine-grained level using tuples instead of topologies. The comprehensive evaluation shows that the proposed framework has good performance and can improve the dependability of the Storm-based applications.

4D CT sorting based on patient internal anatomy

Science.gov (United States)

Li, Ruijiang; Lewis, John H.; Cerviño, Laura I.; Jiang, Steve B.

2009-08-01

Respiratory motion during free-breathing computed tomography (CT) scan may cause significant errors in target definition for tumors in the thorax and upper abdomen. A four-dimensional (4D) CT technique has been widely used for treatment simulation of thoracic and abdominal cancer radiotherapy. The current 4D CT techniques require retrospective sorting of the reconstructed CT slices oversampled at the same couch position. Most sorting methods depend on external surrogates of respiratory motion recorded by extra instruments. However, respiratory signals obtained from these external surrogates may not always accurately represent the internal target motion, especially when irregular breathing patterns occur. We have proposed a new sorting method based on multiple internal anatomical features for multi-slice CT scan acquired in the cine mode. Four features are analyzed in this study, including the air content, lung area, lung density and body area. We use a measure called spatial coherence to select the optimal internal feature at each couch position and to generate the respiratory signals for 4D CT sorting. The proposed method has been evaluated for ten cancer patients (eight with thoracic cancer and two with abdominal cancer). For nine patients, the respiratory signals generated from the combined internal features are well correlated to those from external surrogates recorded by the real-time position management (RPM) system (average correlation: 0.95 ± 0.02), which is better than any individual internal measures at 95% confidence level. For these nine patients, the 4D CT images sorted by the combined internal features are almost identical to those sorted by the RPM signal. For one patient with an irregular breathing pattern, the respiratory signals given by the combined internal features do not correlate well with those from RPM (correlation: 0.68 ± 0.42). In this case, the 4D CT image sorted by our method presents fewer artifacts than that from the RPM signal. Our

Synthesis and antibacterial activity of some Schiff bases derived from 4-aminobenzoic acid

Directory of Open Access Journals (Sweden)

JIGNA PAREKH

2005-10-01

Full Text Available The following Schiff bases have been synthesized: (1 4-[(2-chlorobenzylidene amino]benzoic acid [JP1], (2 4-[(furan-2-ylmethyleneamino]benzoic acid [JP2], (3 4-[(3-phenylallylideneamino]benzoic acid [JP3], (4 4-[(2-hydroxybenzylidene amino]benzoic acid [JP4], (5 4-[(4-hydroxy-3-methoxybenzylideneamino]benzoic acid [JP5] and (6 4-[(3-nitrobenzylideneamino]benzoic acid [JP6]. They were screened as potential antibacterial agents against a number of medically important bacterial strains. The antibacterial activity was studied against A. faecalis ATCC 8750, E. aerogenes ATCC 13048, E. coli ATCC 25922, K. pneumoniae NCIM 2719, S. aureus ATCC 25923, P. vulgaris NCIM 8313, P. aeruginosa ATCC 27853 and S. typhimurium ATCC 23564. The antibacterial activity was evaluated using the Agar Ditch method. The solvents used were 1,4-dioxane and dimethyl sulfoxide. Different effects of the compounds were found in the bacterial strains investigated and the solvents used, suggesting, once again, that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. In the present work, 1,4-dioxane proved to be a good solvent in inhibiting the above stated bacterial strains.

Kinetic and mechanistic studies of base-catalyzed phenylselenoetherification of (Z)- and (E)-hex-4-en-1-ols.

Science.gov (United States)

Divac, Vera M; Puchta, Ralph; Bugarčić, Zorica M

2012-08-02

The mechanism of phenylselenoetherification of (Z)- and (E)-hex-4-en-1-ols using some bases (triethylamine, pyridine, quinoline, 2,2'-bipyridine) as catalysts and some solvents [tetrahydrofuran (THF) and CCl4] as reaction media was examined through studies of kinetics of the cyclization by UV-vis spectrophotometry. It was demonstrated that the intramolecular cyclization is facilitated in the presence of bases as a result of the hydrogen bond between the base and the alkenol's OH group. The rate constants in the base-catalyzed reactions are remarkably influenced by the bulkiness and basicity of the base used and the nature of the considered nitrogen donors. The obtained values for rate constants show that the reaction with triethylamine is the fastest one. THF with higher polarity and higher basic character is better as a solvent than CCl4. Quantum-chemical calculations [MP2(fc)/6-311+G**//B3LYP/6-311+G** + ZPE(B3LYP/6-311+G**] show that the cyclization of (Z)-hex-4-en-1-ol to a tetrahydrofuranoid five-membered ring is kinetically controlled, while the cyclization of (E)-hex-4-en-1-ol to the tetrahydropyranoid six-membered ring is thermodynamically controlled. This is in accordance with previous experimental findings.

Preparation of Affinity Column Based on Zr{sup 4+} Ion for Phosphoproteins Isolation

Energy Technology Data Exchange (ETDEWEB)

Lee, Seon Mi; Bae, In Ae; Park, Jung Hyen; Kim, Tae Dong; Choi, Seong Ho [Hannam University, Daejeon (Korea, Republic of)

2009-06-15

This paper has described about preparation of Zr{sup 4+} affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr{sup 4+} ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr{sup 4+}-immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr{sup 4+} affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr{sup 4+} affinity polymeric microsphere by liquid chromatography. This Zr{sup 4+} affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography.

A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

International Nuclear Information System (INIS)

Martin, Spencer; Rodrigues, George; Gaede, Stewart; Brophy, Mark; Barron, John L; Beauchemin, Steven S; Palma, David; Louie, Alexander V; Yu, Edward; Yaremko, Brian; Ahmad, Belal

2015-01-01

This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development. (paper)

A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

Science.gov (United States)

Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V.; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L.; Beauchemin, Steven S.; Rodrigues, George; Gaede, Stewart

2015-02-01

This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.

Population-based respiratory 4D motion atlas construction and its application for VR simulations of liver punctures

Science.gov (United States)

Mastmeyer, Andre; Wilms, Matthias; Handels, Heinz

2018-03-01

Virtual reality (VR) training simulators of liver needle insertion in the hepatic area of breathing virtual patients often need 4D image data acquisitions as a prerequisite. Here, first a population-based breathing virtual patient 4D atlas is built and second the requirement of a dose-relevant or expensive acquisition of a 4D CT or MRI data set for a new patient can be mitigated by warping the mean atlas motion. The breakthrough contribution of this work is the construction and reuse of population-based, learned 4D motion models.

On the use of EPID-based implanted marker tracking for 4D radiotherapy

International Nuclear Information System (INIS)

Keall, P.J.; Todor, A.D.; Vedam, S.S.; Bartee, C.L.; Siebers, J.V.; Kini, V.R.; Mohan, R.

2004-01-01

Four-dimensional (4D) radiotherapy delivery to dynamically moving tumors requires a real-time signal of the tumor position as a function of time so that the radiation beam can continuously track the tumor during the respiration cycle. The aim of this study was to develop and evaluate an electronic portal imaging device (EPID)-based marker-tracking system that can be used for real-time tumor targeting, or 4D radiotherapy. Three gold cylinders, 3 mm in length and 1 mm in diameter, were implanted in a dynamic lung phantom. The phantom range of motion was 4 cm with a 3-s 'breathing' period. EPID image acquisition parameters were modified, allowing image acquisition in 0.1 s. Images of the stationary and moving phantom were acquired. Software was developed to segment automatically the marker positions from the EPID images. Images acquired in 0.1 s displayed higher noise and a lower signal-noise ratio than those obtained using regular (>1 s) acquisition settings. However, the markers were still clearly visible on the 0.1-s images. The motion of the phantom blurred the images of the markers and further reduced the signal-noise ratio, though they could still be successfully segmented from the images in 10-30 ms of computation time. The positions of gold markers placed in the lung phantom were detected successfully, even for phantom velocities substantially higher than those observed for typical lung tumors. This study shows that using EPID-based marker tracking for 4D radiotherapy is feasible, however, changes in linear accelerator technology and EPID-based image acquisition as well as patient studies are required before this method can be implemented clinically

Absorbed fractions in a voxel-based phantom calculated with the MCNP-4B code.

Science.gov (United States)

Yoriyaz, H; dos Santos, A; Stabin, M G; Cabezas, R

2000-07-01

A new approach for calculating internal dose estimates was developed through the use of a more realistic computational model of the human body. The present technique shows the capability to build a patient-specific phantom with tomography data (a voxel-based phantom) for the simulation of radiation transport and energy deposition using Monte Carlo methods such as in the MCNP-4B code. MCNP-4B absorbed fractions for photons in the mathematical phantom of Snyder et al. agreed well with reference values. Results obtained through radiation transport simulation in the voxel-based phantom, in general, agreed well with reference values. Considerable discrepancies, however, were found in some cases due to two major causes: differences in the organ masses between the phantoms and the occurrence of organ overlap in the voxel-based phantom, which is not considered in the mathematical phantom.

4Kids.org: Topical, Searchable, and Safe Internet-Based Resource for Children and Youth

Science.gov (United States)

Bacon, Melanie; Blood, Leslie; Ault, Marilyn; Adams, Doug

2008-01-01

4Kids.org is an online resource with an accompanying syndicated print publication created to promote safe access to websites and technology literacy. 4Kids.org, created by ALTEC at the University of Kansas in 1995, provides a variety of Internet-based activities as well as access to a database of websites reviewed for educational content,…

4D Flexible Atom-Pairs: An efficient probabilistic conformational space comparison for ligand-based virtual screening

Science.gov (United States)

2011-01-01

Background The performance of 3D-based virtual screening similarity functions is affected by the applied conformations of compounds. Therefore, the results of 3D approaches are often less robust than 2D approaches. The application of 3D methods on multiple conformer data sets normally reduces this weakness, but entails a significant computational overhead. Therefore, we developed a special conformational space encoding by means of Gaussian mixture models and a similarity function that operates on these models. The application of a model-based encoding allows an efficient comparison of the conformational space of compounds. Results Comparisons of our 4D flexible atom-pair approach with over 15 state-of-the-art 2D- and 3D-based virtual screening similarity functions on the 40 data sets of the Directory of Useful Decoys show a robust performance of our approach. Even 3D-based approaches that operate on multiple conformers yield inferior results. The 4D flexible atom-pair method achieves an averaged AUC value of 0.78 on the filtered Directory of Useful Decoys data sets. The best 2D- and 3D-based approaches of this study yield an AUC value of 0.74 and 0.72, respectively. As a result, the 4D flexible atom-pair approach achieves an average rank of 1.25 with respect to 15 other state-of-the-art similarity functions and four different evaluation metrics. Conclusions Our 4D method yields a robust performance on 40 pharmaceutically relevant targets. The conformational space encoding enables an efficient comparison of the conformational space. Therefore, the weakness of the 3D-based approaches on single conformations is circumvented. With over 100,000 similarity calculations on a single desktop CPU, the utilization of the 4D flexible atom-pair in real-world applications is feasible. PMID:21733172

Tripoli-4.4 Jeff-3.1 based libraries; Les bibliotheques Jeff-3.1 pour Tripoli-4.4

Energy Technology Data Exchange (ETDEWEB)

Jouanne, C. [CEA Saclay Dept. Modelisation de Systemes et Structures, 91 - Gif sur Yvette (France); Sublet, J.Ch. [CEA Cadarache, Dept. d' Etudes des Reacteurs, 13 - Saint Paul lez Durance (France)

2006-07-01

Continuous-energy and multi-temperatures TRIPOLI-4.4 libraries, derived from the Joint European Fusion-Fission JEFF-3.1 evaluations, have been generated using the NJOY-99.112 processing code system. They include the continuous-energy neutron JEFF-3.1/General Purpose and thermal S({alpha},{beta}) JEFF-3.1/Thermal libraries and data tables. The processing steps and features are explained together with the Quality Assurance processes and records linked to the generation of such multipurpose libraries. (authors)

G4-STORK: A Geant4-based Monte Carlo reactor kinetics simulation code

International Nuclear Information System (INIS)

Russell, Liam; Buijs, Adriaan; Jonkmans, Guy

2014-01-01

Highlights: • G4-STORK is a new, time-dependent, Monte Carlo code for reactor physics applications. • G4-STORK was built by adapting and expanding on the Geant4 Monte Carlo toolkit. • G4-STORK was designed to simulate short-term fluctuations in reactor cores. • G4-STORK is well suited for simulating sub- and supercritical assemblies. • G4-STORK was verified through comparisons with DRAGON and MCNP. - Abstract: In this paper we introduce G4-STORK (Geant4 STOchastic Reactor Kinetics), a new, time-dependent, Monte Carlo particle tracking code for reactor physics applications. G4-STORK was built by adapting and expanding on the Geant4 Monte Carlo toolkit. The toolkit provides the fundamental physics models and particle tracking algorithms that track each particle in space and time. It is a framework for further development (e.g. for projects such as G4-STORK). G4-STORK derives reactor physics parameters (e.g. k eff ) from the continuous evolution of a population of neutrons in space and time in the given simulation geometry. In this paper we detail the major additions to the Geant4 toolkit that were necessary to create G4-STORK. These include a renormalization process that maintains a manageable number of neutrons in the simulation even in very sub- or supercritical systems, scoring processes (e.g. recording fission locations, total neutrons produced and lost, etc.) that allow G4-STORK to calculate the reactor physics parameters, and dynamic simulation geometries that can change over the course of simulation to illicit reactor kinetics responses (e.g. fuel temperature reactivity feedback). The additions are verified through simple simulations and code-to-code comparisons with established reactor physics codes such as DRAGON and MCNP. Additionally, G4-STORK was developed to run a single simulation in parallel over many processors using MPI (Message Passing Interface) pipes

A highly luminescent dinuclear Eu(III) complex based on 4,4'-bis (4'',4'',4''-trifluoro-1'',3''-dioxobutyl)-o-terphenyl for light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Liu Shenggui [State Key Laboratory of Optoelectronic Materials and Technologies, Ministry of Education Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); School of Chemistry Science and Technology, Zhanjiang Normal University, New Materials Engineering and Technology Development Center of University in Guangdong, Zhanjiang 524048 (China); He Pei; Wang Huihui; Shi Jianxin [State Key Laboratory of Optoelectronic Materials and Technologies, Ministry of Education Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Gong Menglian, E-mail: cesgml@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, Ministry of Education Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

2009-08-15

A dinuclear Eu(III) complex Eu{sub 2}(btbt){sub 3}.4H{sub 2}O.CH{sub 3}CH{sub 2}OH.N(CH{sub 2}CH{sub 3}){sub 3} was synthesized, where H{sub 2}(btbt) was 4,4'-bis (4'',4'',4'',-trifluoro-1'',3''-dioxobutyl)-o-terphenyl. The composition and structure of the complex were characterized by elemental analysis, IR, UV-vis and FAB-MS spectroscopy. The complex emits the characteristic red luminescence of Eu{sup 3+} ion due to the {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 0-4) transitions under {approx}395 nm-light excitation with good luminescent quantum efficiency (32%) and exhibits high thermal stability (337 deg. C). Bright red light-emitting diodes (LEDs) were fabricated by coating the complex onto a {approx}395 nm-emitting InGaN chip. When the mass ratio of the red phosphor to the silicone is 1:30, the efficiency of the fabricated LEDs with the europium complex is 0.98 lm w{sup -1}. The CIE chromaticity coordinates of the LEDs are x = 0.6057 and y = 0.3137, which are close to the National Television Standard Committee (NTSC) standard values for red color. The results indicate that the complex may act as a red component in the fabrication of near UV InGaN-based white light-emitting diodes with high color-rendering index.

3D delivered dose assessment using a 4DCT-based motion model

Energy Technology Data Exchange (ETDEWEB)

Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj, E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu; Lewis, John H., E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Seco, Joao [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)

2015-06-15

Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images

3D delivered dose assessment using a 4DCT-based motion model

International Nuclear Information System (INIS)

Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj; Lewis, John H.; Seco, Joao

2015-01-01

Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images

A fast 4D IMRT/VMAT planning method based on segment aperture morphing.

Science.gov (United States)

Klawikowski, Slade; Tai, An; Ates, Ozgur; Ahunbay, Ergun; Li, X Allen

2018-04-01

Four-dimensional volumetric modulated arc therapy (4D VMAT) and four-dimensional intensity-modulated radiotherapy (4D IMRT) are developing radiation therapy treatment strategies designed to maximize dose conformality, minimize normal tissue dose, and deliver the treatment as efficiently as possible. The patient's entire breathing cycle is captured through 4D imaging modalities and then separated into individual breathing phases for planning purposes. Optimizing multiphase VMAT and IMRT plans is computationally demanding and currently impractical for clinical application. The purpose of this study is to assess a new planning process decreasing the upfront computational time required to optimize multiphased treatment plans while maintaining good plan quality. Optimized VMAT and IMRT plans were created on the end-of-exhale (EOE) breathing phase of 10-phase 4D CT scans with planning tumor volume (PTV)-based targets. These single-phase optimized plans are analogous to single-phase gated treatment plans. The simulated tracked plans were created by deformably registering EOE contours to the remaining breathing phases, recalculating the optimized EOE plan onto the other individual phases and realigning the MLC's relative positions to the PTV border in each of the individual breathing phases using a segment aperture morphing (SAM) algorithm. Doses for each of the 10 phases were calculated with the treatment planning system and deformably transferred back onto the EOE phase and averaged with equal weighting simulating the actual delivered dose a patient would potentially receive in a tracked treatment plan. Plan DVH quality for the 10-phase 4D SAM plans were comparable with the individual EOE optimized treatment plans for the PTV structures as well as the organ at risk structures. SAM-based algorithms out performed simpler isocenter-shifted only approaches. SAM-based 4D planning greatly reduced plan computation time vs individually optimizing all 10 phases. In addition

Reduced graphene oxide wrapped Fe3O4-Co3O4 yolk-shell nanostructures for advanced catalytic oxidation based on sulfate radicals

Science.gov (United States)

Zhang, Lishu; Yang, Xijia; Han, Erfen; Zhao, Lijun; Lian, Jianshe

2017-02-01

In this work, we designed and synthesized a high performance catalyst of reduced graphene oxide (RGO) wrapped Fe3O4-Co3O4 (RGO/Fe3O4-Co3O4) yolk-shell nanostructures for advanced catalytic oxidation based on sulfate radicals. The synergistic catalytic action of the RGO/Fe3O4-Co3O4 yolk-shell nanostructures activate the peroxymonosulfate (PMS) to produce sulfate radicals (SO4rad -) for organic dyes degradation, and the Orange II can be almost completely degradated in 5 min. Meanwhile the RGO wrapping prevents the loss of cobalt in the catalytic process, and the RGO/Fe3O4-Co3O4 can be recycled after catalyzed reaction due to the presence of magnetic iron core. What's more, it can maintain almost the same high catalytic activity even after 10 cycles through repeated NaBH4 reduction treatment. Hence, RGO/Fe3O4-Co3O4 yolk-shell nanostructures possess a great opportunity to become a promising candidate for waste water treatment in industry.

PAM4 based symmetrical 112-Gbps long-reach TWDM-PON

Science.gov (United States)

Wu, Liyu; Gao, Fan; Zhang, Minming; Fu, Songnian; Deng, Lei; Choi, Michael; Chang, Donald; Lei, Gordon K. P.; Liu, Deming

2018-02-01

We experimentally demonstrate cost effective symmetrical 112-Gbps long-reach passive optical network (LR-PON) over 70-km standard signal mode fiber (SSMF), based on pulse amplitude modulation (PAM)-4. Four 10G-class directly modulated lasers (DMLs) at C-band are used for achieving 4 × 28-Gbps downstream transmission, while two 18G-class DMLs at O-band are used to realize 2 × 56-Gbps upstream transmission, without any optical amplification in optical distributed network (ODN). Both dispersion compensation fiber (DCF) for downstream signal and praseodymium-doped fiber amplifier (PDFA) for upstream signal are equipped at optical line terminal (OLT). Meanwhile, sparse Volterra filter (SVF) equalizer is proposed to mitigate the transmission impairments with substantial reduction of computation complexity. Finally, we can successfully provide a loss budget of 33 dB per downstream wavelength channel, indicating of 64 optical network units (ONUs) with more than 1.25 Gbps per ONU.

Optical Absorption and Electron Injection of 4-(Cyanomethylbenzoic Acid Based Dyes: A DFT Study

Directory of Open Access Journals (Sweden)

Yuehua Zhang

2015-01-01

Full Text Available Density functional theory (DFT and time-dependent density functional theory (TDDFT calculations were carried out to study the ground state geometries, electronic structures, and absorption spectra of 4-(cyanomethylbenzoic acid based dyes (AG1 and AG2 used for dye-sensitized solar cells (DSSCs. The excited states properties and the thermodynamical parameters of electron injection were studied. The results showed that (a two dyes have uncoplanar structures along the donor unit and conjugated bridge space, (b two sensitizers exhibited intense absorption in the UV-Vis region, and (c the excited state oxidation potential was higher than the conduction band edge of TiO2 photoanode. As a result, a solar cell based on the 4-(cyanomethylbenzoic acid based dyes exhibited well photovoltaic performance. Furthermore, nine dyes were designed on the basis of AG1 and AG2 to improve optical response and electron injection.

High molecular weight polyurethanes and a polyurethane urea based on 1,4-butanediisocyanate

NARCIS (Netherlands)

Spaans, CJ; de Groot, JH; Dekens, FG; Pennings, AJ

New biomedical polyurethanes and a polyurethane urea based on epsilon-caprolactone and 1,4-butanediisocyanate have been developed. On degradation, only non-toxic products are produced. The polyurethane urea with poly(epsilon-caprolactone) soft segments and butanediisocyanate/butanediamine hard

Performance tests of a CaSO4:Dy based thermoluminescence personal dosemeter

International Nuclear Information System (INIS)

Azorin, J.; Gutierrez, A.; Niewiadomski, T.

1986-01-01

In order to replace LiF commercial thermoluminescence dosemeters (TLDs) now used in personnel monitoring, we developed a TLD personnel monitoring badge based on pellets of CaSO 4 :Dy bound in pure KBr placed in plastic holders provided with 0.8 mm Pb filters to compensate for the energy dependence of CaSO 4 :Dy. Performance tests, based on the proposals of international standards for TLDs intended to be used as general deep tissue personal dosemeters, were done by developing the detailed test methods both for the tests required by the International Atomic Energy Agency (fading, linearity, effect of fluorescent light and sunlight and stability under standard climatic conditions) and to meet the requirements of the International Electrotechnical Commission (batch homogeneity, detection threshold, stability of zero point repeatibility and residual). Initial tests showed a high residual and an increase of inhomogeneity. However, these drawbacks were overcome by changing the annealing procedure and the readout conditions. Using these new conditions TLDs met all the requirements for personal dosemeters. (author)

Widely Tunable 4th Order Switched Gm -C Band-Pass Filter Based on N-Path Filters

NARCIS (Netherlands)

Darvishi, M.; van der Zee, Ronan A.R.; Klumperink, Eric A.M.; Nauta, Bram

2012-01-01

Abstract—A widely tunable 4th order BPF based on the subtraction of two 2nd order 4-path passive-mixer filters with slightly different center frequencies is proposed. The center frequency of each 4-path filter is slightly shifted relative to its clock frequency (one upward and the other one

4D CAD Based Method for Supporting Coordination of Urban Subsurface Utility Projects

NARCIS (Netherlands)

olde Scholtenhuis, Léon Luc; Hartmann, T.; Doree, Andries G.

Coordinators of inner city utility construction works face increasing difficulty in managing their projects due to tight physical restrictions, strict deadlines and growing stakeholder fragmentation. This paper therefore presents a 4D CAD based coordination method that supports project plan scoping,

Up to 30 mW of broadly tunable CW green-to-orange light, based on sum-frequency mixing of Cr4+:forsterite and Nd:YVO4 lasers

DEFF Research Database (Denmark)

Mortensen, Jesper Liltorp; McWilliam, Allan; G. Leburn, Christopher

2006-01-01

Efficient generation of continuous-wave (CW) tunable light in the yellow region is reported. The method is based on sum-frequency mixing of a tunable Cr4+:forsterite laser with a Nd:YVO4 laser. A periodically poled lithium niobate crystal was placed intra-cavity in a Nd:YVO4 laser, and the Cr4...

Preparations, structures and properties of heterobimetallic complexes based on tetrahydrofuran-2,3,4,5-tetracarboxylate

International Nuclear Information System (INIS)

Jia, Tian-Jing; Li, Shu-Mu; Cao, Wei; Li, Li-Cun; Zheng, Xiang-Jun; Yuan, Da-Qiang

2013-01-01

Transition heterobimetallic metal-organic frameworks based on tetrahydrofuran-2,3,4,5-tetracarboxylicate (FTA), namely [M(H 2 O) 6 ][Cu 2 M(FTA) 2 (H 2 O) 2 ]·4H 2 O [M=Mn (1), Co (2)], and [CuZn(FTA)(H 2 O) 5 ]·H 2 O (3) have been synthesized and characterized. Single-crystal X-ray diffraction indicates that complexes 1 and 2 are isomorphic. In 1 and 2, FTA ligand links the metal ions to a 2-D wave-like negative-charged layer with a topology of (4;6 2 ) 2 (4;6 3 ;8 2 ) 2 (6). They possess 1-D channels with [M(H 2 O) 6 ] 2+ and lattice water molecules enclathrated. While in the complex 3, Cu 2+ and Zn 2+ ions are bridged by FTA to a 2-D neutral layer structure with a (8) 2 (8 4 ;12 2 ) topology. Magnetic properties of 1–3 were analyzed in connection with their structures, which show that there exist weak antiferromagnetic interactions between metal ions. - Graphical abstract: Three heterobimetallic MOFs were constructed through the size-selectivity of TFA coordination sites for different transition metal ions based on the concept of “Hard and Soft Acids and Bases”. Highlights: ► Complexes 1 and 3 contain 2-D wave-like negative-charged layers. ► Complex 2 is a 2-D neutral layer structure with a (8) 2 (8 4 ;12 2 ) topology. ► Complexes 1–3 are the first example of heterobimetallic MOFs based on FTA. ► The coordination sites of FTA show size-selectivity to metal ions

Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

Science.gov (United States)

Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Pauly, Jérôme; Coutinho, João A. P.

2010-01-01

Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS. PMID:20480041

Graphene and g-C3N4 based photocatalysts for NOx removal: A review

Science.gov (United States)

Nikokavoura, Aspasia; Trapalis, Christos

2018-02-01

NOx liberated into atmosphere from automobile exhausts and fossil fuel combustion, comprise the major air pollutants. They are responsible for serious environmental problems such as acid rain, ozone accumulation, haze and photochemical smog. Besides they contribute to the deterioration of human health by causing decrease of the lung function and respiratory problems. The application of photocatalytic methods in order to mitigate the presence of NOx in the atmosphere is preferable as they are environmentally friendly, mild and low cost. Therefore, in this review, the photocatalytic activity of g-C3N4 and graphene based composites towards NOx removal was discussed. NOx oxidation to non volatile nitrates on the surface of graphene and g-C3N4 based photocatalysts has attracted much interest during the last years due to their structures with unique features such as large specific surface area, thermal and chemical stability and enhanced visible light utilization. The formation of 2D-2D intimate heterojunctions between graphene or g-C3N4 and other components ensures the enhanced charge transfer, lifetime of electron/hole pairs and thus photocatalytic activity. The increased visible light harvesting also contributes to their usefulness as effective photocatalytic materials. In the present work, the advantages of these novel photocatalysts and the differences/similarities between them were exhaustively highlighted. The role of graphene as catalyst promoter, electron reservoir, support and photosensitizer in its photocatalytic composites was emphasized. The effect of g-C3N4 doping and copolymerization with metals/semiconductors on its photocatalytic activity towards NOx oxidation was thoroughly discussed. Besides, the preparation methods, photocatalytic efficiencies, type of irradiation, utilization of appropriate cocatalysts, and reaction mechanisms during the photocatalytic NOx removal by graphene and g-C3N4 composies, were summarized. It was demonstrated that in the vast

Scintillation detectors based on poly-2,4-dimethylstyrene: Structure peculiarities and radiation damage

International Nuclear Information System (INIS)

Gunder, O.A.; Voronkina, N.I.; Kopina, I.V.

1995-01-01

Scintillation detectors based on poly-2,4-dimethyl styrene (P-2,4-DMS) are studied. Investigated is the influence of two methyl groups present in the benzene ring on the energy, spectral and structural characteristics of the polymer. The said factors are assumed to result in the detectors high light output and radiation resistance. It is shown that under radiolysis (77 K) the radiation yield of the paramagnetic centers of P-2,4-DMS exceeds that of polystyrene (PST) by ∼ 1.5. Unlike PST film, the luminescence spectra of P-2,4-DMS are characterized by the presence of both excimer (320-340 nm) and monomer (292 nm) bands. Revealed are the distinction in the nature of the optical characteristics of macroradicals and the efficiency of energy transfer in gamma-irradiated PST and P-2,4-DMS scintillators. The relation between the super-molecular structure of the polymers and the interaction of their macroradicals with molecular O 2 is stated

Molecular Bases of PDE4D Inhibition by Memory-Enhancing GEBR Library Compounds.

Science.gov (United States)

Prosdocimi, Tommaso; Mollica, Luca; Donini, Stefano; Semrau, Marta S; Lucarelli, Anna Paola; Aiolfi, Egidio; Cavalli, Andrea; Storici, Paola; Alfei, Silvana; Brullo, Chiara; Bruno, Olga; Parisini, Emilio

2018-05-01

Selected members of the large rolipram-related GEBR family of type 4 phosphodiesterase (PDE4) inhibitors have been shown to facilitate long-term potentiation and to improve memory functions without causing emetic-like behavior in rodents. Despite their micromolar-range binding affinities and their promising pharmacological and toxicological profiles, few if any structure-activity relationship studies have been performed to elucidate the molecular bases of their action. Here, we report the crystal structure of a number of GEBR library compounds in complex with the catalytic domain of PDE4D as well as their inhibitory profiles for both the long PDE4D3 isoform and the catalytic domain alone. Furthermore, we assessed the stability of the observed ligand conformations in the context of the intact enzyme using molecular dynamics simulations. The longer and more flexible ligands appear to be capable of forming contacts with the regulatory portion of the enzyme, thus possibly allowing some degree of selectivity between the different PDE4 isoforms.

Synthesis, antifungal evaluation and in silico study of novel Schiff bases derived from 4-amino-5(3,5-dimethoxy-phenyl-4H-1,2,4-triazol-3-thiol

Directory of Open Access Journals (Sweden)

N.S. Hari Narayana Moorthy

2017-05-01

Full Text Available A novel series of Schiff bases based on of 4-amino-5-(3,5-dimethoxy-phenyl-4H-1,2,4-triazol-3-thiol scaffold was prepared by heating thiocarbohydrazide and 3,5,-dimethoxy benzoic acid at the temperature above its meting point, and subsequently, treating with substituted benzaldehydes. The chemical constituents in the synthesized compounds were confirmed by IR, Mass, 1H NMR spectroscopy and elemental analysis and the antifungal activity was evaluated against Candida albicans. The structure activity relationship analysis shows that the chloride substituted derivatives possess promising activity in micromolar concentration and also the hydroxy phenyl derivatives exhibited considerable activity at 128 μg/ml. But other compounds with amino, furan and methoxy substitutions did not show antifungal activity till the concentration of 512 μg/ml. In silico pharmacokinetic prediction shows that all the compounds obeyed Lipinski rule of 5 and are free of toxicity and metabolically stable. Pharmacophore analysis revealed that the aromatic/hydrophobic and aromatic/acceptor/donor features in the compounds are essential for the activity. The predicted cardiotoxicity (hERG and lethal effect of the synthesized compounds will permit us to carry out further in vitro and in vivo toxicity studies.

Spectroscopic, Electrochemical and DFT Studies of Phosphorescent Homoleptic Cyclometalated Iridium(III) Complexes Based on Substituted 4-Fluorophenylvinyl- and 4-Methoxyphenylvinylquinolines.

Science.gov (United States)

Adeloye, Adewale O; Mphahlele, Malose J; Adekunle, Abolanle S; Rhyman, Lydia; Ramasami, Ponnadurai

2017-09-21

This study reports the synthesis and comparative investigation of the substituent effects of a new series of highly luminescent homoleptic tris-cyclometalated iridium(III) complexes of the type [Ir(N ˄ C)₃]. These are based on two ligand type derivatives comprising of 4-fluorophenylvinylquinolines and 4-methoxyphenylvinylquinolines with electron-donating and/or electron-withdrawing groups as aryl substituents at 2-position. The structures of the ligands and their complexes were characterized by means of FT-IR, UV-Vis and NMR spectrometry complemented with photoluminescence and cyclic voltammetry. The photophysical properties of 2-aryl-4-(4-fluorophenylvinyl)quinoline and its corresponding complex were also studied using the density functional theory method. The photoluminescent properties of the ligands and the corresponding complexes showed high fluorescent intensities and quantum yields in solvents of different polarities. The photoluminescence spectra of the complexes in solid film, showed common transmission curves at longer wavelengths maximum (λ em = 697 nm) possibly originating from the interference of scattered light of higher-order transmission of monochromators.

Experimental investigation of irregular motion impact on 4D PET-based particle therapy monitoring

International Nuclear Information System (INIS)

Tian, Y; Stützer, K; Enghardt, W; Priegnitz, M; Helmbrecht, S; Fiedler, F; Bert, C

2016-01-01

Particle therapy positron emission tomography (PT-PET) is an in vivo and non-invasive imaging technique to monitor treatment delivery in particle therapy. The inevitable patient respiratory motion during irradiation causes artefacts and inaccurate activity distribution in PET images. Four-dimensional (4D) maximum likelihood expectation maximisation (4D MLEM) allows for a compensation of these effects, but has up to now been restricted to regular motion for PT-PET investigations. However, intra-fractional motion during treatment might differ from that during acquisition of the 4D-planning CT (e.g. amplitude variation, baseline drift) and therefore might induce inaccurate 4D PET reconstruction results. This study investigates the impact of different irregular analytical one-dimensional (1D) motion patterns on PT-PET imaging by means of experiments with a radioactive source and irradiated moving phantoms. Three sorting methods, namely phase sorting, equal amplitude sorting and event-based amplitude sorting, were applied to manage the PET list-mode data. The influence of these sorting methods on the motion compensating algorithm has been analysed. The event-based amplitude sorting showed a superior performance and it is applicable for irregular motions with  ⩽4 mm amplitude elongation and drift. For motion with 10 mm baseline drift, the normalised root mean square error was as high as 10.5% and a 10 mm range deviation was observed. (note)

Experimental investigation of irregular motion impact on 4D PET-based particle therapy monitoring

Science.gov (United States)

Tian, Y.; Stützer, K.; Enghardt, W.; Priegnitz, M.; Helmbrecht, S.; Bert, C.; Fiedler, F.

2016-01-01

Particle therapy positron emission tomography (PT-PET) is an in vivo and non-invasive imaging technique to monitor treatment delivery in particle therapy. The inevitable patient respiratory motion during irradiation causes artefacts and inaccurate activity distribution in PET images. Four-dimensional (4D) maximum likelihood expectation maximisation (4D MLEM) allows for a compensation of these effects, but has up to now been restricted to regular motion for PT-PET investigations. However, intra-fractional motion during treatment might differ from that during acquisition of the 4D-planning CT (e.g. amplitude variation, baseline drift) and therefore might induce inaccurate 4D PET reconstruction results. This study investigates the impact of different irregular analytical one-dimensional (1D) motion patterns on PT-PET imaging by means of experiments with a radioactive source and irradiated moving phantoms. Three sorting methods, namely phase sorting, equal amplitude sorting and event-based amplitude sorting, were applied to manage the PET list-mode data. The influence of these sorting methods on the motion compensating algorithm has been analysed. The event-based amplitude sorting showed a superior performance and it is applicable for irregular motions with  ⩽4 mm amplitude elongation and drift. For motion with 10 mm baseline drift, the normalised root mean square error was as high as 10.5% and a 10 mm range deviation was observed.

Two novel Pb(II) coordination polymers (CPs) based on 4-(4-oxopyridin-1(4H)-yl) and 3-(4-oxopyridin-1(4H)-yl) phthalic acid: Band gaps, structures, and their photoelectrocatalytic properties in CO2-saturated system

Science.gov (United States)

Yan, Zhi Shuo; Long, Ji Ying; Gong, Yun; Lin, Jian Hua

2018-05-01

Based on 4-(4-oxopyridin-1(4H)-yl) phthalic acid (H2L1) and 3-(4-oxopyridin-1(4H)-yl) phthalic acid (H2L2), two novel Pb(II) coordination polymers (CPs) formulated as [Pb4Cl4·(L1)2·H2O]n (CP 1), [Pb3Cl4·L2·H2O]n (CP 2) were solvothermally synthesized and characterized by single-crystal X-ray diffraction. The two novel Pb(II) CPs (CPs 1 and 2) possessed different structures. Density functional theory (DFT) calculations revealed the two CPs had different band structures yet the characteristic of semiconductors in common. Their valence band (VB) and conduction band (CB) positions were determined by Mott-Schottky and UV-visible diffuse reflectance analyses. The photoelectrocatalytic performance of the two CPs towards CO2 reduction were tested by photocurrent responses at various applied potentials. And the E =-1.4 V vs SCE (-0.74 V vs NHE) was selected as the required potential according to the regulation of photocurrent responses at various tested potentials in CO2-saturated system. The photoelectrocatalytic performance of CP 2 was superior to that of CP 1 owing to the well-matched CB position of CP 2 and CO2 reduction potentials at the required potential of -1.4 V vs SCE (-0.74 V vs NHE). In addition, the photoelectrolytic experiment were performed 1 h in the CO2-saturated 0.2 M Na2SO4 solution at the required potential of -1.4 V vs SCE (-0.74 V vs NHE) with and without illumination, and we initially demonstrated the influence of visible light in the CO2-saturated photoelectrocatalytic measurement system and the reason of stability in 1 h chronoamperometry.

High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides

Energy Technology Data Exchange (ETDEWEB)

Daniel A. Mosher; Xia Tang; Ronald J. Brown; Sarah Arsenault; Salvatore Saitta; Bruce L. Laube; Robert H. Dold; Donald L. Anton

2007-07-27

This final report describes the motivations, activities and results of the hydrogen storage independent project "High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides" performed by the United Technologies Research Center under the Department of Energy Hydrogen Program, contract # DE-FC36-02AL67610. The objectives of the project were to identify and address the key systems technologies associated with applying complex hydride materials, particularly ones which differ from those for conventional metal hydride based storage. This involved the design, fabrication and testing of two prototype systems based on the hydrogen storage material NaAlH4. Safety testing, catalysis studies, heat exchanger optimization, reaction kinetics modeling, thermochemical finite element analysis, powder densification development and material neutralization were elements included in the effort.

Ion selective electrode for cesium based on 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene.

Science.gov (United States)

Ramanjaneyulu, P S; Singh, Parminder; Sayi, Y S; Chawla, H M; Ramakumar, K L

2010-03-15

A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium was fabricated with 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene as ionophore. Different membrane constituents were investigated to realise optimum performance of the ISE developed. Of the four plasticizers and two ion additives studied, the best response was observed with membrane having 2-nitro phenyl octyl ether (oNPOE) as plasticizer and potassium tetrakis (perchloro phenyl) borate (KTpClPB) as ion additive. Linear response over concentration range of 10(-5)-10(-1)M CsCl was obtained. The Nernstian slope of the response was 56 mV per decade for Cs with a response time less than 20s. Matched potential method has been applied to find out the selectivity for Cs over several ions like Rb(+), K(+), Na(+), NH(4)(+), Sr(2+), Ba(2+), Ca(2+), Mg(2+), Cu(2+), Pb(2+), Zn(2+), Ni(2+) and Ce(3+). The response of ISE for Cs(+) was fairly constant over the pH range of 3-11. The lifetime of the electrode is 9 months which is the longest life for any membrane-based Cs-ISE so far developed. The concentration of cesium in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing atomic absorption spectrometry. (c) 2009 Elsevier B.V. All rights reserved.

Silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases-Novel noncompetitive α-glucosidase inhibitors.

Science.gov (United States)

Zheng, Jingwei; Ma, Lin

2015-01-01

A series of silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases were designed and tested for α-glucosidase inhibition. Our results indicate that all the silver complexes (4a-18a) possessed strong inhibitory activity at μmolL(-1) level, especially glutamine (12a) and histidine (18a) Schiff base silver(I) complexes exhibited an IC50 value of less than 0.01μmolL(-1). This series of compounds exhibited noncompetitive inhibition characteristics in kinetic studies. In addition, we investigated the mechanism of inhibition and the structure-activity relationships of the amino acid Schiff base silver complexes. Our results reveal that Schiff base silver complexes may be explored for their therapeutic potential as alternatives of α-glucosidase inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adaptive patch-based POCS approach for super resolution reconstruction of 4D-CT lung data

International Nuclear Information System (INIS)

Wang, Tingting; Cao, Lei; Yang, Wei; Feng, Qianjin; Chen, Wufan; Zhang, Yu

2015-01-01

Image enhancement of lung four-dimensional computed tomography (4D-CT) data is highly important because image resolution remains a crucial point in lung cancer radiotherapy. In this paper, we proposed a method for lung 4D-CT super resolution (SR) by using an adaptive-patch-based projection onto convex sets (POCS) approach, which is in contrast with the global POCS SR algorithm, to recover fine details with lesser artifacts in images. The main contribution of this patch-based approach is that the interfering local structure from other phases can be rejected by employing a similar patch adaptive selection strategy. The effectiveness of our approach is demonstrated through experiments on simulated images and real lung 4D-CT datasets. A comparison with previously published SR reconstruction methods highlights the favorable characteristics of the proposed method. (paper)

ACSEPT-Partitioning technologies and actinide science: Towards pilot facilities in Europe

International Nuclear Information System (INIS)

Bourg, S.; Hill, C.; Caravaca, C.; Rhodes, C.; Ekberg, C.; Taylor, R.; Geist, A.; Modolo, G.; Cassayre, L.; Malmbeck, R.; Harrison, M.; Angelis, G. de; Espartero, A.; Bouvet, S.; Ouvrier, N.

2011-01-01

deliver relevant flowsheets and recommendations to prepare for future demonstrations at a pilot level. After more than two years of work, significant progress was achieved in process development with the demonstration of the SANEX and innovative SANEX flowsheets. Chemical systems were selected for GANEX and are under study. In addition, efforts were made to increase collaborations, mutualise and homogenise procedures and share good practices. Based on these assessments, it is now time to look at the future challenges to overcome. A training and education program is implemented to share the knowledge among the partitioning community, present and future generations of researchers. Specific attention is paid to the funding of post-doctorate fellowships, two having been appointed respectively at the end of 2008 and at the end of 2009. Through this training and education programme, the first ACSEPT International Workshop was organised last March in Lisbon, Portugal. It gave an emphasis to young researchers' contributions (two thirds of the contributions) and allowed young scientists to meet and exchange with international recognised experts.

Crystal structures and magnetic properties of iron (III)-based phosphates: Na4NiFe(PO4)3 and Na2Ni2Fe(PO4)3

International Nuclear Information System (INIS)

Essehli, Rachid; Bali, Brahim El; Benmokhtar, Said; Bouziane, Khalid; Manoun, Bouchaib; Abdalslam, Mouner Ahmed; Ehrenberg, Helmut

2011-01-01

Graphical abstract: A perspective view of the Na 2 Ni 2 Fe(PO 4 ) 3 structure along the [0 0 1] direction. Both compounds seem to exibit antiferromagnetic interactions between magnetic entities at low temperature. Display Omitted Research highlights: → Nasicon and Alluaudite compounds, Iron(III)-based phosphates, Crystal structures of Na 4 NiFe(PO 4 ) 3 and Na 2 Ni 2 Fe(PO 4 ) 3 . → Magnetism behaviours of Na 4 NiFe(PO 4 ) 3 and Na 2 Ni 2 Fe(PO 4 ) 3 . → Antiferromagnetism interactions. → Mossbauer spectroscopy. - Abstract: Crystal structures from two new phosphates Na 4 NiFe(PO 4 ) 3 (I) and Na 2 Ni 2 Fe(PO 4 ) 3 (II) have been determined by single crystal X-ray diffraction analysis. Compound (I) crystallizes in a rhombohedral system (S. G: R-3c, Z = 6, a = 8.7350(9) A, c = 21.643(4) A, R 1 = 0.041, wR 2 =0.120). Compound (II) crystallizes in a monoclinic system (S. G: C2/c, Z = 4, a = 11.729(7) A, b = 12.433(5) A, c = 6.431(2) A, β = 113.66(4) o , R 1 = 0.043, wR 2 =0.111). The three-dimensional structure of (I) is closely related to the Nasicon structural type, consisting of corner sharing [(Ni/Fe)O 6 ] octahedra and [PO 4 ] tetrahedra forming [NiFe(PO 4 ) 3 ] 4+ units which align in chains along the c-axis. The Na + cations fill up trigonal antiprismatic sites within these chains. The crystal structure of (II) belongs to the alluaudite type. Its open framework results from [Ni 2 O 10 ] units of edge-sharing [NiO 6 ] octahedra, which alternate with [FeO 6 ] octahedra that form infinite chains. Coordination of these chains yields two distinct tunnels in which site Na + . The magnetization data of compound (I) reveal antiferromagnetic (AFM) interactions by the onset of deviations from a Curie-Weiss behaviour at low temperature as confirmed by Moessbauer measurements performed at 4.2 K. The corresponding temperature dependence of the reciprocal susceptibility χ -1 follows a typical Curie-Weiss behaviour for T > 105 K. A canted AFM state is proposed for

A Compton camera application for the GAMOS GEANT4-based framework

Energy Technology Data Exchange (ETDEWEB)

Harkness, L.J., E-mail: ljh@ns.ph.liv.ac.uk [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Arce, P. [Department of Basic Research, CIEMAT, Madrid (Spain); Judson, D.S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Dormand, J.; Jones, M.; Nolan, P.J.; Sampson, J.A.; Scraggs, D.P.; Sweeney, A. [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)

2012-04-11

Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

Multimodal MRI-based study in patients with SPG4 mutations.

Directory of Open Access Journals (Sweden)

Thiago J R Rezende

Full Text Available Mutations in the SPG4 gene (SPG4-HSP are the most frequent cause of hereditary spastic paraplegia, but the extent of the neurodegeneration related to the disease is not yet known. Therefore, our objective is to identify regions of the central nervous system damaged in patients with SPG4-HSP using a multi-modal neuroimaging approach. In addition, we aimed to identify possible clinical correlates of such damage. Eleven patients (mean age 46.0 ± 15.0 years, 8 men with molecular confirmation of hereditary spastic paraplegia, and 23 matched healthy controls (mean age 51.4 ± 14.1years, 17 men underwent MRI scans in a 3T scanner. We used 3D T1 images to perform volumetric measurements of the brain and spinal cord. We then performed tract-based spatial statistics and tractography analyses of diffusion tensor images to assess microstructural integrity of white matter tracts. Disease severity was quantified with the Spastic Paraplegia Rating Scale. Correlations were then carried out between MRI metrics and clinical data. Volumetric analyses did not identify macroscopic abnormalities in the brain of hereditary spastic paraplegia patients. In contrast, we found extensive fractional anisotropy reduction in the corticospinal tracts, cingulate gyri and splenium of the corpus callosum. Spinal cord morphometry identified atrophy without flattening in the group of patients with hereditary spastic paraplegia. Fractional anisotropy of the corpus callosum and pyramidal tracts did correlate with disease severity. Hereditary spastic paraplegia is characterized by relative sparing of the cortical mantle and remarkable damage to the distal portions of the corticospinal tracts, extending into the spinal cord.

Synthesis and characterization of some novel 1,2,4-triazoles, 1,3,4-thiadiazoles and Schiff bases incorporating imidazole moiety as potential antimicrobial agents

KAUST Repository

Aouad, Mohamed Reda

2015-05-23

(1,4,5-Triphenylimidazol-2-yl-thio)butyric acid hydrazide (3) was obtained via alkylation of 1,4,5-triphenylimidazol-2- thiol (1) with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfide in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol- -2-yl)thiopropyl]-2H-1,2,4-triazole-3-thione (4) in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate afforded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthio)butanoyl]-4-alkyl/arylthiosemicarbazides (5-7), which upon refluxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole - -3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with different aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.

Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

International Nuclear Information System (INIS)

Wang, Chao; Zhao, Jun; Xia, Liang; Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan

2016-01-01

Three new coordination polymers, namely, {[Ni(H 2 L)(bix)(H 2 O) 2 ]·2h 2 O} n (1), {[Ni(HL)(Hdpa)(H 2 O) 2 ]·H 2 O} n (2), {[Ni(L) 0.5 (bpp)(H 2 O)]·H 2 O} n (3) (H 4 L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H 4 L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6 6 -dia-type framework with H 4 L ligand adopts a μ 2 -bridging mode with two symmetry-related carboxylate groups in μ 1 -η 1 :η 0 monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, in which the H 4 L ligand adopts a μ 2 -bridging mode with two carboxylate groups in μ 1 -η 1 :η 1 and μ 1 -η 1 :η 0 monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H 4 L ligand displays a μ 4 -bridging coordination mode. The H 4 L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6 6 -dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled” strategy is significant potential for network design.

Identification of novel KCNQ4 openers by a high-throughput fluorescence-based thallium flux assay.

Science.gov (United States)

Li, Qunyi; Rottländer, Mario; Xu, Mingkai; Christoffersen, Claus Tornby; Frederiksen, Kristen; Wang, Ming-Wei; Jensen, Henrik Sindal

2011-11-01

To develop a real-time thallium flux assay for high-throughput screening (HTS) of human KCNQ4 (Kv7.4) potassium channel openers, we used CHO-K1 cells stably expressing human KCNQ4 channel protein and a thallium-sensitive dye based on the permeability of thallium through potassium channels. The electrophysiological and pharmacological properties of the cell line expressing the KCNQ4 protein were found to be in agreement with that reported elsewhere. The EC(50) values of the positive control compound (retigabine) determined by the thallium and (86)rubidium flux assays were comparable to and consistent with those documented in the literature. Signal-to-background (S/B) ratio and Z factor of the thallium influx assay system were assessed to be 8.82 and 0.63, respectively. In a large-scale screening of 98,960 synthetic and natural compounds using the thallium influx assay, 76 compounds displayed consistent KCNQ4 activation, and of these 6 compounds demonstrated EC(50) values of less than 20 μmol/L and 2 demonstrated EC(50) values of less than 1 μmol/L. Taken together, the fluorescence-based thallium flux assay is a highly efficient, automatable, and robust tool to screen potential KCNQ4 openers. This approach may also be expanded to identify and evaluate potential modulators of other potassium channels. Copyright © 2011 Elsevier Inc. All rights reserved.

Nondoped deep blue OLEDs based on Bis-(4-benzenesulfonyl-phenyl)-9-phenyl-9H-carbazoles

International Nuclear Information System (INIS)

Huang, Bin; Yin, Zhihui; Ban, Xinxin; Ma, Zhongming; Jiang, Wei; Tian, Wenwen; Yang, Min; Ye, Shanghui; Lin, Baoping; Sun, Yueming

2016-01-01

Two bipolar materials based on 9-phenylcarbazole and diphenyl sulfone for nondoped deep blue OLEDs, namely bis-(4-benzenesulfonyl-phenyl)-9-phenyl-9H-carbazoles, have been designed and synthesized by Suzuki coupling reactions. Their thermal, photophysical, and electrochemical properties have been systematically investigated. The nondoped devices using 3,6–bis–(4-benzenesulfonyl-phenyl)-9-phenyl-9H-carbazoles and 2,7-bis-(4-benzenesulfonyl-phenyl)-9-phenyl-9H-carbazoles as the emitters show deep blue emission color with peaks at 424 and 444 nm, and the Commission Internationale de l'Eclairage (CIE) coordinates of (0.177, 0.117) and (0.160, 0.117), respectively. Furthermore, these materials based devices have high color-purity with small width at half-maximum (FWHM) of 65 and 73 nm, respectively. The results provide a novel approach for the design of deep blue emitter for nondoped OLEDs.

GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

Science.gov (United States)

Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

2015-07-01

In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

International Nuclear Information System (INIS)

Lemaréchal, Yannick; Bert, Julien; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris; Falconnet, Claire; Després, Philippe; Valeri, Antoine

2015-01-01

In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125 I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10 −6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. (paper)

The influence of reduced graphene oxide on electrical conductivity of LiFePO4-based composite as cathode material

International Nuclear Information System (INIS)

Arifin, Muhammad; Aimon, Akfiny Hasdi; Winata, Toto; Abdullah, Mikrajuddin; Iskandar, Ferry

2016-01-01

LiFePO 4 is fascinating cathode active materials for Li-ion batteries application because of their high electrochemical performance such as a stable voltage at 3.45 V and high specific capacity at 170 mAh.g −1 . However, their low intrinsic electronic conductivity and low ionic diffusion are still the hindrance for their further application on Li-ion batteries. Therefore, the efforts to improve their conductivity are very important to elevate their prospecting application as cathode materials. Herein, we reported preparation of additional of reduced Graphene Oxide (rGO) into LiFePO 4 -based composite via hydrothermal method and the influence of rGO on electrical conductivity of LiFePO 4 −based composite by varying mass of rGO in composition. Vibration of LiFePO 4 -based composite was detected on Fourier Transform Infrared Spectroscopy (FTIR) spectra, while single phase of LiFePO 4 nanocrystal was observed on X-Ray Diffraction (XRD) pattern, it furthermore, Scanning Electron Microscopy (SEM) images showed that rGO was distributed around LiFePO4-based composite. Finally, the 4-point probe measurement result confirmed that the optimum electrical conductivity is in additional 2 wt% rGO for range 1 to 2 wt% rGO

Novel organo soluble poly imides and polyimide nano composites based on 1,4-bis(4-aminophenyl)-1,3,4-oxadiaz olyl)benzene, BAOB, via BAOB-modified organo clay

International Nuclear Information System (INIS)

Mansoori, Y.; Darvishi, K.

2014-01-01

New, thermally stable poly imides (PI) containing a 1,3,4-oxadiazole ring in the polymer backbone based on 1,4-bis((4-aminophenyl)-1,3,4-oxadiaz olyl)benzene, BAOB, were synthesized. The prepared polymers were soluble in polar and aprotic solvents. The obtained results reveal that within the prepared polymers, polyimide which has been obtained from BAOB and 4,4-oxy diphthalic dianhydride, ODPA, has the most improved thermal properties. In the next part, thermally stable organophilic clay was obtained via cation exchange reaction between sodium montmorillonite (Na-MMT) and the hydrochloride salt of BAOB. Then, a series of PI/clay nano composite materials (PCNs) were synthesized from the in situ polymerization reaction of BAOB and ODPA via thermal imidization, BAOB-MMT was used as the filler at different concentrations. Intercalation of polymer chains within the organo clay galleries was confirmed by W XRD. The glass transition temperature is increased with respect to pristine PI for PCNs 1-3 wt %. At high clay loadings, the aggregation of organo clay particles results in a decrease in T g . In the Sem images of the pure polymer too many micro-cracks were observed in the background, while surface homogeneity of PCN 1 wt % is increased and micro-cracks are reduced. (Author)

Novel organo soluble poly imides and polyimide nano composites based on 1,4-bis(4-aminophenyl)-1,3,4-oxadiaz olyl)benzene, BAOB, via BAOB-modified organo clay

Energy Technology Data Exchange (ETDEWEB)

Mansoori, Y.; Darvishi, K., E-mail: ya_mansoori@yahoo.com [University of Mohaghegh Ardabili, Faculty of Science, Department of Applied Chemistry, Daneshgah, Ardabil (Iran, Islamic Republic of)

2014-10-01

New, thermally stable poly imides (PI) containing a 1,3,4-oxadiazole ring in the polymer backbone based on 1,4-bis((4-aminophenyl)-1,3,4-oxadiaz olyl)benzene, BAOB, were synthesized. The prepared polymers were soluble in polar and aprotic solvents. The obtained results reveal that within the prepared polymers, polyimide which has been obtained from BAOB and 4,4-oxy diphthalic dianhydride, ODPA, has the most improved thermal properties. In the next part, thermally stable organophilic clay was obtained via cation exchange reaction between sodium montmorillonite (Na-MMT) and the hydrochloride salt of BAOB. Then, a series of PI/clay nano composite materials (PCNs) were synthesized from the in situ polymerization reaction of BAOB and ODPA via thermal imidization, BAOB-MMT was used as the filler at different concentrations. Intercalation of polymer chains within the organo clay galleries was confirmed by W XRD. The glass transition temperature is increased with respect to pristine PI for PCNs 1-3 wt %. At high clay loadings, the aggregation of organo clay particles results in a decrease in T{sub g}. In the Sem images of the pure polymer too many micro-cracks were observed in the background, while surface homogeneity of PCN 1 wt % is increased and micro-cracks are reduced. (Author)

Geotectonic evolution of lunar LQ-4 region based on multisource data

Directory of Open Access Journals (Sweden)

Jianping Chen

2014-03-01

Full Text Available The Sinus Iridum region, the first choice for China's “Lunar Exploration Project” is located at the center of the lunar LQ-4 area and is the site of Chang'e-3 (CE-3's soft landing. To make the scientific exploration of Chang'e-3 more targeted and scientific, and to obtain a better macro-level understanding of the geotectonic environment of the Sinus Iridum region, the tectonic elements in LQ-4 region have been studied and the typical structures were analyzed statistically using data from CE-1, Clementine, LRO and Lunar Prospector missions. Also, the mineral components and periods of mare basalt activities in the study area have been ascertained. The present study divides the tectonic units and establishes the major tectonic events and sequence of evolution in the study area based on morphology, mineral constituents, and tectonic element distribution.

Ba3(P1−xMnxO4)2 : Blue/green inorganic materials based on ...

Indian Academy of Sciences (India)

‡Chemical Science and Technology Division, National Institute for Interdisciplinary Science and Technology ... We describe a blue/green inorganic material, Ba3(P1−xMnxO4)2 (I) based on tetrahedral MnO3−. 4 .... the synthesis at 600–950.

Ultimate realistic losses of ZrF/sub 4/ based IR fibres

International Nuclear Information System (INIS)

France, P.W.; Carter, S.F.; Moore, M.W.; Williams, J.R.

1986-01-01

An estimation has been made of the minimum loss that might be expected in ZrF/sub 4/ based IR fibre taking into account extrinsic absorption losses as well as the intrinsic loss mechanisms associated with the IR edge and Rayleigh scattering. The results suggest that an overall loss of approximately 0.03 dB/km might be expected at 2.56 μm, a factor of three higher than the intrinsic loss and a factor of seven lower than overall loss in a typical silica fibre

Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

Directory of Open Access Journals (Sweden)

Saeed Taghvaee Ganjali

2001-03-01

Full Text Available Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2 is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.

Electrospun ZnFe{sub 2}O{sub 4}-based nanofiber composites with enhanced supercapacitive properties

Energy Technology Data Exchange (ETDEWEB)

Agyemang, Frank Ofori; Kim, Hern, E-mail: hernkim@mju.ac.kr

2016-09-15

Highlights: • Electrospun ZnFe{sub 2}O{sub 4}-based nanofibers were successfully fabricated. • The electrochemical properties of ZnFe{sub 2}O{sub 4} were enhanced by addition of ZnO and Fe{sub 2}O{sub 3.} • A specific capacitance of 590 F g{sup −1} was achieved from a CV curve at a scan rate of 5 mV s{sup −1.} • The electrode materials poses excellent cycling stability even after 3000 cycles. - Abstract: Herein, we are reporting a facile method to synthesis ZnFe{sub 2}O{sub 4}-based nanofibers (ZnFe{sub 2}O{sub 4}, ZnO–ZnFe{sub 2}O{sub 4} and Fe{sub 2}O{sub 3}–ZnFe{sub 2}O{sub 4}) via the electrospinning technique using zinc acetonate and ferric acetonate as the metal oxide precursor and polyvinyl pyrrolidone (PVP) as the polymer. The as-prepared electrospun nanofiber composites were calcined at 500 °C to obtain crystalline porous nanofibers. The effect of different compositions on the morphology of each sample as well as their electrochemical properties when employed as electrode materials was studied. The results show that the as-prepared electrodes exhibited excellent performance with their specific capacitances calculated from the CV curves as 590, 490 and 450 F g{sup −1} for Fe{sub 2}O{sub 3}–ZnFe{sub 2}O{sub 4}, ZnO–ZnFe{sub 2}O{sub 4} and ZnFe{sub 2}O{sub 4} respectively at a scan rate of 5 mV s{sup −1}. Excellent stability of the electrodes was also observed even after 3000 cycles. The results obtained suggest these electrode materials might be promising candidates for supercapacitor application.

Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

Energy Technology Data Exchange (ETDEWEB)

Wang, Chao [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); Zhao, Jun, E-mail: junzhao08@126.com [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Xia, Liang [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China)

2016-06-15

Three new coordination polymers, namely, {[Ni(H_2L)(bix)(H_2O)_2]·2h_2O}{sub n} (1), {[Ni(HL)(Hdpa)(H_2O)_2]·H_2O}{sub n} (2), {[Ni(L)_0_._5(bpp)(H_2O)]·H_2O}{sub n} (3) (H{sub 4}L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H{sub 4}L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6{sup 6}-dia-type framework with H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two symmetry-related carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 0} monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, in which the H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 1} and μ{sub 1}-η{sup 1}:η{sup 0} monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H{sub 4}L ligand displays a μ{sub 4}-bridging coordination mode. The H{sub 4}L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6{sup 6}-dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled�

UPLC-MS/MS based diagnostics for epithelial ovarian cancer using fully sialylated C4-binding protein.

Science.gov (United States)

Tanabe, Kazuhiro; Matsuo, Koji; Miyazawa, Masaki; Hayashi, Masaru; Ikeda, Masae; Shida, Masako; Hirasawa, Takeshi; Sho, Ryuichiro; Mikami, Mikio

2018-05-01

Serum levels of fully sialylated C4-binding protein (FS-C4BP) are remarkably elevated in patients with epithelial ovarian cancer (EOC) and can be used as a marker to distinguish ovarian clear cell carcinoma from endometrioma. This study aimed to develop a stable, robust and reliable liquid chromatography-hybrid mass spectrometry (UPLC-MS/MS) based diagnostic method that would generalize FS-C4BP as a clinical EOC biomarker. Glycopeptides derived from 20 μL of trypsin-digested serum glycoprotein were analyzed via UPLC equipped with an electrospray ionization time-of-flight mass spectrometer. This UPLC-MS/MS-based diagnostic method was optimized for FS-C4BP and validated using sera from 119 patients with EOC and 127 women without cancer. A1958 (C4BP peptide with two fully sialylated biantennary glycans) was selected as a marker of FS-C4BP because its level in serum was highest among FS-C4BP family members. Preparation and UPLC-MS/MS were optimized for A1958, and performance and robustness were significantly improved relative to our previous method. An area under the curve analysis of the FS-C4BP index receiver operating characteristic curve revealed that the ratio between A1958 and A1813 (C4BP peptide with two partially sialylated biantennary glycans) reached 85%. A combination of the FS-C4BP index and carbohydrate antigen-125 levels further enhanced the sensitivity and specificity. © 2017 The Authors. Biomedical Chromatography published by John Wiley & Sons Ltd.

Research on Service-Integrating-Based C4ISR System Simulation Environment%基于服务集成的C4ISR系统仿真环境研究

Institute of Scientific and Technical Information of China (English)

鲍广宇; 毛少杰; 居真奇; 刘晓明

2008-01-01

The future C4ISR systems will be based on the information grid environment, which is constructed with service-integrating technology. According to this, Modeling and Simulation (M&S) of C41SR systems will be based on the service-integrating technology, too. Firstly the principle of service-integrating was introduced, and then a service-integrating-based simulation environment was proposed to support the C4ISR system simulation and experiments in an SOA environment.%未来的C4ISR系统将建立在使用服务集成技术的信息栅格环境下,相应地,C4ISR建模与仿真系统也将基于服务集成技术构建.介绍了服务集成技术的原理,基于仿真服务总线技术,提出一个基于服务集成的C4ISR系统仿真环境,分析了该环境的技术体系结构和关键技术,为支持面向服务体系下的C4ISR系统仿真实验提供了一种可选解决方案.

Reference geometry-based detection of (4D-)CT motion artifacts: a feasibility study

Science.gov (United States)

Werner, René; Gauer, Tobias

2015-03-01

Respiration-correlated computed tomography (4D or 3D+t CT) can be considered as standard of care in radiation therapy treatment planning for lung and liver lesions. The decision about an application of motion management devices and the estimation of patient-specific motion effects on the dose distribution relies on precise motion assessment in the planning 4D CT data { which is impeded in case of CT motion artifacts. The development of image-based/post-processing approaches to reduce motion artifacts would benefit from precise detection and localization of the artifacts. Simple slice-by-slice comparison of intensity values and threshold-based analysis of related metrics suffer from- depending on the threshold- high false-positive or -negative rates. In this work, we propose exploiting prior knowledge about `ideal' (= artifact free) reference geometries to stabilize metric-based artifact detection by transferring (multi-)atlas-based concepts to this specific task. Two variants are introduced and evaluated: (S1) analysis and comparison of warped atlas data obtained by repeated non-linear atlas-to-patient registration with different levels of regularization; (S2) direct analysis of vector field properties (divergence, curl magnitude) of the atlas-to-patient transformation. Feasibility of approaches (S1) and (S2) is evaluated by motion-phantom data and intra-subject experiments (four patients) as well as - adopting a multi-atlas strategy- inter-subject investigations (twelve patients involved). It is demonstrated that especially sorting/double structure artifacts can be precisely detected and localized by (S1). In contrast, (S2) suffers from high false positive rates.

Production of thermoluminescent dosemeters based on MgB4O7: Dy and MgB4O7: Tm

International Nuclear Information System (INIS)

Souza, Luiza Freire de; Souza, Divanizia N.

2013-01-01

The thermoluminescent dosimetry (TL) is a well-established technique for the detection of ionizing radiation in hospitals, clinics, and industrial establishments where there is the need to quantify the radiation. For this practice is require the use phosphors which are sensitive to radiation. Some phosphors are already commonly used in this practice, for example, TLD-100 (LiF: Mg, Ti), CaSO 4 :Tm and CaSO 4 :Dy. A compound that was most recently introduced in dosimetry and has many advantageous features to detect neutrons, electrons and gamma is the magnesium tetraborate (MgB 4 O 7 ), but the undoped material is not good for dosimetry, since signal does not show satisfactory thermoluminescence. The present work presents the analysis of the compound MgB 4 O 7 when doped with rare earth elements, thulium (Tm) and dysprosium (Dy). The production of MgB 4 O 7 : Dy and MgB 4 O 7 : Tm occurred under acidic conditions. Following the process of crystal growth, several tests were made on phosphors produced to verify the quality of materials as TL dosimeter. Initially, was made the identification of the crystalline phases found in the material, using the technique of X-ray diffractometry, and then were evaluated and compared the TL emission curves of the crystals with two different types of dopants, to this, the samples were irradiated with different radiation sources: 137 Cs (0,66 MeV), 60 Co (1.25 MeV) and X-rays (0.41 MeV) and based on the results was evaluated the energy dependence of phosphors. Another characteristic analyzed, was the decay of TL signal for the material (fading). The results show that the material can be an excellent TL dosimeter when doped with rare earth elements Dy and Tm. (author)

ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

Science.gov (United States)

Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

2012-06-07

Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

Science.gov (United States)

Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

2011-01-01

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

A review of the demonstration of innovative solvent extraction processes for the recovery of trivalent minor actinides from PUREX raffinate

International Nuclear Information System (INIS)

Modolo, G.; Wilden, A.; Geist, A.; Magnusson, D.; Malmbeck, R.

2012-01-01

The selective partitioning (P) of long-lived minor actinides from highly active waste solutions and their transmutation (T) to short-lived or stable isotopes by nuclear reactions will reduce the long-term hazard of the high-level waste and significantly shorten the time needed to ensure their safe confinement in a repository. The present paper summarizes the on-going research activities at Forschungszentrum Juelich (FZJ), Karlsruher Institut fuer Technologie (KIT) and Institute for Transuranium Elements (ITU) in the field of actinide partitioning using innovative solvent extraction processes. European research over the last few decades, i.e. in the NEWPART, PARTNEW and EUROPART programmes, has resulted in the development of multi-cycle processes for minor actinide partitioning. These multi-cycle processes are based on the co-separation of trivalent actinides and lanthanides (e.g. by the DIAMEX process), followed by the subsequent actinide(III)/lanthanide(III) group separation in the SANEX process. The current direction of research for the development of innovative processes within the recent European ACSEPT project is discussed additionally. This paper is focused on the development of flow-sheets for recovery of americium and curium from highly active waste solutions. The flow-sheets are verified by demonstration processes, in centrifugal contactors, using synthetic or genuine fuel solutions. The feasibility of the processes is also discussed. (orig.)

Use of 4-Dimensional Computed Tomography-Based Ventilation Imaging to Correlate Lung Dose and Function With Clinical Outcomes

International Nuclear Information System (INIS)

Vinogradskiy, Yevgeniy; Castillo, Richard; Castillo, Edward; Tucker, Susan L.; Liao, Zhongxing; Guerrero, Thomas; Martel, Mary K.

2013-01-01

Purpose: Four-dimensional computed tomography (4DCT)-based ventilation is an emerging imaging modality that can be used in the thoracic treatment planning process. The clinical benefit of using ventilation images in radiation treatment plans remains to be tested. The purpose of the current work was to test the potential benefit of using ventilation in treatment planning by evaluating whether dose to highly ventilated regions of the lung resulted in increased incidence of clinical toxicity. Methods and Materials: Pretreatment 4DCT data were used to compute pretreatment ventilation images for 96 lung cancer patients. Ventilation images were calculated using 4DCT data, deformable image registration, and a density-change based algorithm. Dose–volume and ventilation-based dose function metrics were computed for each patient. The ability of the dose–volume and ventilation-based dose–function metrics to predict for severe (grade 3+) radiation pneumonitis was assessed using logistic regression analysis, area under the curve (AUC) metrics, and bootstrap methods. Results: A specific patient example is presented that demonstrates how incorporating ventilation-based functional information can help separate patients with and without toxicity. The logistic regression significance values were all lower for the dose–function metrics (range P=.093-.250) than for their dose–volume equivalents (range, P=.331-.580). The AUC values were all greater for the dose–function metrics (range, 0.569-0.620) than for their dose–volume equivalents (range, 0.500-0.544). Bootstrap results revealed an improvement in model fit using dose–function metrics compared to dose–volume metrics that approached significance (range, P=.118-.155). Conclusions: To our knowledge, this is the first study that attempts to correlate lung dose and 4DCT ventilation-based function to thoracic toxicity after radiation therapy. Although the results were not significant at the .05 level, our data suggests

Correspondence model-based 4D VMAT dose simulation for analysis of local metastasis recurrence after extracranial SBRT

Science.gov (United States)

Sothmann, T.; Gauer, T.; Wilms, M.; Werner, R.

2017-12-01

The purpose of this study is to introduce a novel approach to incorporate patient-specific breathing variability information into 4D dose simulation of volumetric arc therapy (VMAT)-based stereotactic body radiotherapy (SBRT) of extracranial metastases. Feasibility of the approach is illustrated by application to treatment planning and motion data of lung and liver metastasis patients. The novel 4D dose simulation approach makes use of a regression-based correspondence model that allows representing patient motion variability by breathing signal-steered interpolation and extrapolation of deformable image registration motion fields. To predict the internal patient motion during treatment with only external breathing signal measurements being available, the patients’ internal motion information and external breathing signals acquired during 4D CT imaging were correlated. Combining the correspondence model, patient-specific breathing signal measurements during treatment and time-resolved information about dose delivery, reconstruction of a motion variability-affected dose becomes possible. As a proof of concept, the proposed approach is illustrated by a retrospective 4D simulation of VMAT-based SBRT treatment of ten patients with 15 treated lung and liver metastases and known clinical endpoints for the individual metastases (local metastasis recurrence yes/no). Resulting 4D-simulated dose distributions were compared to motion-affected dose distributions estimated by standard 4D CT-only dose accumulation and the originally (i.e. statically) planned dose distributions by means of GTV D98 indices (dose to 98% of the GTV volume). A potential linkage of metastasis-specific endpoints to differences between GTV D98 indices of planned and 4D-simulated dose distributions was analyzed.

3,4-Phenylenedioxythiophene (PheDOT) Based Hole-Transporting Materials for Perovskite Solar Cells.

Science.gov (United States)

Chen, Jian; Chen, Bai-Xue; Zhang, Fang-Shuai; Yu, Hui-Juan; Ma, Shuang; Kuang, Dai-Bin; Shao, Guang; Su, Cheng-Yong

2016-04-05

Two new electron-rich molecules based on 3,4-phenylenedioxythiophene (PheDOT) were synthesized and successfully adopted as hole-transporting materials (HTMs) in perovskite solar cells (PSCs). X-ray diffraction, absorption spectra, photoluminescence spectra, electrochemical properties, thermal stabilities, hole mobilities, conductivities, and photovoltaic parameters of PSCs based on these two HTMs were compared with each other. By introducing methoxy substituents into the main skeleton, the energy levels of PheDOT-core HTM were tuned to match with the perovskite, and its hole mobility was also improved (1.33×10(-4)  cm(2)  V(-1)  s(-1) , being higher than that of spiro-OMeTAD, 2.34×10(-5)  cm(2)  V(-1)  s(-1)). The PSC based on MeO-PheDOT as HTM exhibits a short-circuit current density (Jsc) of 18.31 mA cm(-2) , an open-circuit potential (Voc ) of 0.914 V, and a fill factor (FF) of 0.636, yielding an encouraging power conversion efficiency (PCE) of 10.64 % under AM 1.5G illumination. These results give some insight into how the molecular structures of HTMs affect their performances and pave the way for developing high-efficiency and low-cost HTMs for PSCs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermally reactive Thiazolo[5,4-d]thiazole based copolymers for high photochemical stability in polymer solar cells

DEFF Research Database (Denmark)

Helgesen, Martin; Vesterager Madsen, Morten; Andreasen, Birgitta

2011-01-01

New thermally reactive copolymers based on dithienylthiazolo[5,4-d]thiazole (DTZ) and silolodithiophene (SDT) have been synthesized and explored in bulk heterojunction solar cells as mixtures with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). In thin films the polymers had optical band gaps...... in the range of 1.64-1.80 eV. For solubility the polymers have incorporated alkyl groups on the SDT unit and thermally removable ester groups on the DTZ unit that can be eliminated around 200 °C for improved photochemical stability in thin films. The bulkiness of the alkyl chains on the SDT unit proved...... to be very significant in terms of photovoltaic performance of the polymer:PCBM solar cells. Polymers based on 4,4-dihexyl-4H-silolo[3,2-b:4,5-b′]dithiophene reached power conversion efficiencies (PCEs) up to 1.45% but changing the alkyl groups to more bulky ethylhexyl chains reduced the PCE to 1.17%. More...

Destabilized LiBH4-NaAlH4 Mixtures Doped with Titanium Based Catalysts

DEFF Research Database (Denmark)

Shi, Qing; Yu, Xuebin; Feidenhans'l, Robert

2008-01-01

We investigate the hydrogen storage properties of the mixed complex hydride LiBH4-NaAlH4 system, both undoped and doped with a TiCl3 additive. The mixed system is found to initiate a transformation to LiBH4-NaAlH4 after ball-milling, and the doped system is found to have a significant lower hydro...

Sequential application of ligand and structure based modeling approaches to index chemicals for their hH4R antagonism.

Directory of Open Access Journals (Sweden)

Matteo Pappalardo

Full Text Available The human histamine H4 receptor (hH4R, a member of the G-protein coupled receptors (GPCR family, is an increasingly attractive drug target. It plays a key role in many cell pathways and many hH4R ligands are studied for the treatment of several inflammatory, allergic and autoimmune disorders, as well as for analgesic activity. Due to the challenging difficulties in the experimental elucidation of hH4R structure, virtual screening campaigns are normally run on homology based models. However, a wealth of information about the chemical properties of GPCR ligands has also accumulated over the last few years and an appropriate combination of these ligand-based knowledge with structure-based molecular modeling studies emerges as a promising strategy for computer-assisted drug design. Here, two chemoinformatics techniques, the Intelligent Learning Engine (ILE and Iterative Stochastic Elimination (ISE approach, were used to index chemicals for their hH4R bioactivity. An application of the prediction model on external test set composed of more than 160 hH4R antagonists picked from the chEMBL database gave enrichment factor of 16.4. A virtual high throughput screening on ZINC database was carried out, picking ∼ 4000 chemicals highly indexed as H4R antagonists' candidates. Next, a series of 3D models of hH4R were generated by molecular modeling and molecular dynamics simulations performed in fully atomistic lipid membranes. The efficacy of the hH4R 3D models in discrimination between actives and non-actives were checked and the 3D model with the best performance was chosen for further docking studies performed on the focused library. The output of these docking studies was a consensus library of 11 highly active scored drug candidates. Our findings suggest that a sequential combination of ligand-based chemoinformatics approaches with structure-based ones has the potential to improve the success rate in discovering new biologically active GPCR drugs and

Sequential application of ligand and structure based modeling approaches to index chemicals for their hH4R antagonism.

Science.gov (United States)

Pappalardo, Matteo; Shachaf, Nir; Basile, Livia; Milardi, Danilo; Zeidan, Mouhammed; Raiyn, Jamal; Guccione, Salvatore; Rayan, Anwar

2014-01-01

The human histamine H4 receptor (hH4R), a member of the G-protein coupled receptors (GPCR) family, is an increasingly attractive drug target. It plays a key role in many cell pathways and many hH4R ligands are studied for the treatment of several inflammatory, allergic and autoimmune disorders, as well as for analgesic activity. Due to the challenging difficulties in the experimental elucidation of hH4R structure, virtual screening campaigns are normally run on homology based models. However, a wealth of information about the chemical properties of GPCR ligands has also accumulated over the last few years and an appropriate combination of these ligand-based knowledge with structure-based molecular modeling studies emerges as a promising strategy for computer-assisted drug design. Here, two chemoinformatics techniques, the Intelligent Learning Engine (ILE) and Iterative Stochastic Elimination (ISE) approach, were used to index chemicals for their hH4R bioactivity. An application of the prediction model on external test set composed of more than 160 hH4R antagonists picked from the chEMBL database gave enrichment factor of 16.4. A virtual high throughput screening on ZINC database was carried out, picking ∼ 4000 chemicals highly indexed as H4R antagonists' candidates. Next, a series of 3D models of hH4R were generated by molecular modeling and molecular dynamics simulations performed in fully atomistic lipid membranes. The efficacy of the hH4R 3D models in discrimination between actives and non-actives were checked and the 3D model with the best performance was chosen for further docking studies performed on the focused library. The output of these docking studies was a consensus library of 11 highly active scored drug candidates. Our findings suggest that a sequential combination of ligand-based chemoinformatics approaches with structure-based ones has the potential to improve the success rate in discovering new biologically active GPCR drugs and increase the

A new physics-based self-heating effect model for 4H-SiC MESFETs

International Nuclear Information System (INIS)

Cao Quanjun; Zhang Yimen; Zhang Yuming

2008-01-01

A new self-heating effect model for 4H-SiC MESFETs is proposed based on a combination of an analytical and a computer aided design (CAD) oriented drain current model. The circuit oriented expressions of 4H-SiC low-field electron mobility and incomplete ionization rate, which are related to temperature, are presented in this model, which are used to estimate the self-heating effect of 4H-SiC MESFETs. The verification of the present model is made, and the good agreement between simulated results and measured data of DC I – V curves with the self-heating effect is obtained. (condensed matter: electronic structure, electrical, magnetic, and optical propertiesx)

Structural and energetic characterization of the emissive RNA alphabet based on the isothiazolo[4,3-d]pyrimidine heterocycle core

KAUST Repository

Chawla, Mohit

2016-06-01

We present theoretical characterization of fluorescent non-natural nucleobases, tzA, tzG, tzC, and tzU, derived from the isothiazolo[4,3-d]pyrimidine heterocycle. Consistent with the experimental evidence, our calculations show that the non-natural bases have minimal impact on the geometry and stability of the classical Watson-Crick base pairs, allowing them to accurately mimic natural bases in a RNA duplex, in terms of H-bonding. In contrast, our calculations indicate that H-bonded base pairs involving the Hoogsteen edge are destabilized relative to their natural counterparts. Analysis of the photophysical properties of the non-natural bases allowed us to correlate their absorption/emission peaks to the strong impact of the modification on the energy of the lowest unoccupied molecular orbital, LUMO, which is stabilized by roughly 1.0-1.2 eV relative to the natural analogues, while the highest occupied molecular orbital, HOMO, is not substantially affected. As a result, the HOMO-LUMO gap is reduced from 5.3-5.5 eV in the natural bases to 4.0-4.4 eV in the modified ones, with a consequent bathochromic shift in the absorption and emission spectra. © 2016 the Owner Societies.

Structural and energetic characterization of the emissive RNA alphabet based on the isothiazolo[4,3-d]pyrimidine heterocycle core

KAUST Repository

Chawla, Mohit; Poater, Albert; Oliva, Romina; Cavallo, Luigi

2016-01-01

We present theoretical characterization of fluorescent non-natural nucleobases, tzA, tzG, tzC, and tzU, derived from the isothiazolo[4,3-d]pyrimidine heterocycle. Consistent with the experimental evidence, our calculations show that the non-natural bases have minimal impact on the geometry and stability of the classical Watson-Crick base pairs, allowing them to accurately mimic natural bases in a RNA duplex, in terms of H-bonding. In contrast, our calculations indicate that H-bonded base pairs involving the Hoogsteen edge are destabilized relative to their natural counterparts. Analysis of the photophysical properties of the non-natural bases allowed us to correlate their absorption/emission peaks to the strong impact of the modification on the energy of the lowest unoccupied molecular orbital, LUMO, which is stabilized by roughly 1.0-1.2 eV relative to the natural analogues, while the highest occupied molecular orbital, HOMO, is not substantially affected. As a result, the HOMO-LUMO gap is reduced from 5.3-5.5 eV in the natural bases to 4.0-4.4 eV in the modified ones, with a consequent bathochromic shift in the absorption and emission spectra. © 2016 the Owner Societies.

Base pair mismatches and carcinogen-modified bases in DNA: an NMR study of G x T and G x O4meT pairing in dodecanucleotide duplexes

International Nuclear Information System (INIS)

Kalnik, M.W.; Kouchakdjian, M.; Li, B.F.L.; Swann, P.F.; Patel, D.J.

1988-01-01

High-resolution two-dimensional NMR studies have been completed on the self-complementary d(C-G-C-G-A-G-C-T-T-G-C-G) duplex (designated G x T 12-mer) and the self-complementary d(C-G-C-G-A-G-C-T-O 4 meT-G-C-G) duplex (designated G x O 4 meT 12-mer) containing G x T and G x O 4 meT pairs at identical positions four base pairs in from either end of the duplex. The exchangeable and nonexchangeable proton resonances have been assigned from an analysis of two-dimensional nuclear Overhauser enhancement (NOESY) spectra for the G x T 12-mer and G x O 4 meT 12-mer duplexes in H 2 O and D 2 O solution. The guanosine and thymidine imino protons in the G x T mismatch resonate at 10.57 and 11.98 ppm, respectively, and exhibit a strong NOE between themselves and to imino protons of flanking base pairs in the G x T 12-mer duplex. The large upfield chemical shift of this proton relative to that of the imino proton resonance of G in the G x T mismatch or in G x C base pairs indicates that hydrogen bonding to O 4 meT is either very weak or absent. This guanosine imino proton has an NOE to the OCH 3 group of O 4 meT across the pair and NOEs to the imino protons of flanking base pairs. Taken together with data from the NMR of nonexchangeable protons, this shows that both G and O 4 meT have anti-glycosidic torsion angles and are stacked into the duplex. Comparison of the intensity of the NOEs between the guanosine imino proton and the OCH 3 of O 4 meT as well as other protons in its vicinity demonstrates that the OCH 3 group of O 4 meT adopts the syn orientation with respect to N3 of the methylated thymidine. The authors propose an alternate base pairing mode stabilized by one short hydrogen bond between the 2-amino group of guanosine and the 2-carbonyl group of O 4 met

Long-term prognosis of patients with chronic hepatitis C who did not receive interferon-based therapy: causes of death and analysis based on the FIB-4 index.

Science.gov (United States)

Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori; Kiriyama, Seiki; Tanikawa, Makoto; Hisanaga, Yasuhiro; Kanamori, Akira; Kitabatake, Shusuke; Yama, Tsuyoki; Tanaka, Junko

2016-04-01

Interferon (IFN)-based therapy has been reported to reduce the liver-related mortality rate in patients with chronic hepatitis C virus (HCV) infection. However, predictors of survival and causes of death, including non-liver-related causes, have not been sufficiently investigated in chronic HCV patients who have not received IFN-based therapy. A total of 1723 patients with chronic HCV infection who were not treated with IFN-based therapy were enrolled. Survival from liver-related diseases and non-liver-related diseases and causes of death were analyzed on the basis of the fibrosis-4 (FIB-4) index, an index of liver fibrosis. The median follow-up duration was 10.3 years. Of 465 patients who died during the follow-up period, 48.4 % died of liver-related diseases; of the remainder, 51.6 % died of non-liver-related diseases. On the basis of FIB-4 index, the liver-related mortality rate increased as the FIB-4 index increased: 16.1 % in the FIB-4 index 3.25 group (p death (hazard ratio 13.020; 95 % confidence interval 4.155-40.770) and non-liver-related death (hazard ratio 1.667; 95 % confidence interval 1.188-2.340). Patients with chronic HCV infection and an elevated FIB-4 index may benefit from monitoring not only for the development of liver-related diseases but also for the development of non-liver-related diseases.

Task-shifting of CD4 T cell count monitoring by the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration: Implication for decentralization in resource-constrained settings.

Science.gov (United States)

Kouabosso, André; Mossoro-Kpinde, Christian Diamant; Bouassa, Ralph-Sydney Mboumba; Longo, Jean De Dieu; Mbeko Simaleko, Marcel; Grésenguet, Gérard; Bélec, Laurent

2018-04-01

The accuracy of CD4 T cell monitoring by the recently developed flow cytometry-based CD4 T cell counting Muse™ Auto CD4/CD4% Assay analyzer (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) was evaluated in trained lay providers against laboratory technicians. After 2 days of training on the Muse™ Auto CD4/CD4% analyzer, EDTA-blood samples from 6 HIV-positive and 4 HIV-negative individuals were used for CD4 T cell counting in triplicate in parallel by 12 trained lay providers as compared to 10 lab technicians. Mean number of CD4 T cells in absolute number was 829 ± 380 cells/μl by lay providers and 794 ± 409 cells/μl by technicians (P > 0.05); and in percentage 36.2 ± 14.8%CD4 by lay providers and 36.1 ± 15.0%CD4 by laboratory technician (P > 0.05). The unweighted linear regression and Passing-Bablok regression analyses on CD4 T cell results expressed in absolute count revealed moderate correlation between CD4 T cell counts obtained by lay providers and lab technicians. The mean absolute bias measured by Bland-Altman analysis between CD4 T cell/μl obtained by lay providers and lab technicians was -3.41 cells/μl. Intra-assay coefficient of variance (CV) of Muse™ Auto CD4/CD4% in absolute number was 10.1% by lay providers and 8.5% by lab technicians (P > 0.05), and in percentage 5.5% by lay providers and 4.4% by lab technicians (P > 0.05). The inter-assay CV of Muse™ Auto CD4/CD4% in absolute number was 13.4% by lay providers and 10.3% by lab technicians (P > 0.05), and in percentage 7.8% by lay providers and 6.9% by lab technicians (P > 0.05). The study demonstrates the feasibility of CD4 T cell counting using the alternative flow cytometer Muse™ Auto CD4/CD4% analyzer by trained lay providers and therefore the practical possibility of decentralization CD4 T cell counting to health community centers. Copyright © 2018. Published by Elsevier B.V.

Comparison of Mg-based multilayers for solar He II radiation at 30.4 nm wavelength

Energy Technology Data Exchange (ETDEWEB)

Zhu Jingtao; Zhou Sika; Li Haochuan; Huang Qiushi; Wang Zhanshan; Le Guen, Karine; Hu, Min-Hui; Andre, Jean-Michel; Jonnard, Philippe

2010-07-10

Mg-based multilayers, including SiC/Mg, Co/Mg, B4C/Mg, and Si/Mg, are investigated for solar imaging and a He II calibration lamp at a 30.4 nm wavelength. These multilayers were fabricated by a magnetron sputtering method and characterized by x-ray reflection. The reflectivities of these multilayers were measured by synchrotron radiation. Near-normal-incidence reflectivities of Co/Mg and SiC/Mg multilayer mirrors are as high as 40.3% and 44.6%, respectively, while those of B4C/Mg and Si/Mg mirrors are too low for application. The measured results suggest that SiC/Mg, Co/Mg multilayers are promising for a 30.4 nm wavelength.

Ageing and Water-Based Processing of LiFeMnPO4 Secondary Agglomerates and Its Effects on Electrochemical Characteristics

Directory of Open Access Journals (Sweden)

Benjamin Starke

2017-12-01

Full Text Available LiFeMnPO4 secondary agglomerates have been aged under different temperature and moisture conditions. The aged and pristine powder samples were then processed to water- and solvent-based cathodes. Structural studies by means of neutron and X-ray diffraction revealed that neither ageing nor water-based processing significantly modified the crystal structure of LiFeMnPO4 secondary agglomerates. Electrochemical characterization was carried out with full-cells. It was found that long-term cycling is similar independent of the solvent used for slurry preparation. Full-cells assembled with water-based cathodes show a better C-rate capability due to a more homogeneous distribution of cathode constituents compared to solvent-based ones. In no case was any negative effect of initial active material ageing on the electrochemical performance found. During ageing and processing, LiFeMnPO4 is effectively protected by carbon coating and water can be completely removed by drying since it is only reversibly bound. This contribution shows that LiFeMnPO4 secondary agglomerates allow simplified active material handling and have a high potential for sustainable water-based electrode manufacturing.

Direct synthesis of aqueous quantum dots through 4,4'-bipyridine-based twin ligand strategy.

Science.gov (United States)

Kalita, Mausam; Cingarapu, Sreeram; Roy, Santanu; Park, Seok Chan; Higgins, Daniel; Jankowiak, Ryszard; Chikan, Viktor; Klabunde, Kenneth J; Bossmann, Stefan H

2012-04-16

We report a new class of derivatized 4,4'-bipyridinium ligands for use in synthesizing highly fluorescent, extremely stable, water-soluble CdSe and CdTe quantum dots (QDs) for bioconjugation. We employed an evaporation-condensation technique, also known as solvated metal atom dispersion (SMAD), followed by a digestive ripening procedure. This method has been used to synthesize both metal nanoparticles and semiconductors in the gram scale with several stabilizing ligands in various solvents. The SMAD technique comprised evaporation condensation and stabilization of CdSe or CdTe in tetrahydrofuran. The as-prepared product was then digestively ripened in both water and dimethyl formamide, leading to narrowing of the particle size distributions. The ligands were synthesized by nucleophilic substitution (S(N)2) reactions using 4,4'-bipyridine as a nucleophile. Confocal microscopy images revealed the orange color of the nanocrystalline QDs with diameters of ~5 nm. The size has been confirmed by using transmission electron microscopy. As a part of our strategy, 85% of the 4,4'-bipyridinium salt was synthesized as propionic acid derivative and used to both stabilize the QDs in water and label basic amino acids and different biomarkers utilizing the carboxylic acid functional group. Fifteen percent of the 4,4'-bipyridinium salt was synthesized as N-propyl maleimide and used as a second ligand to label any protein containing the amino acid cysteine by means of a 1,4-Michael addition. © 2012 American Chemical Society

A radiogallium-DOTA-based bivalent peptidic ligand targeting a chemokine receptor, CXCR4, for tumor imaging.

Science.gov (United States)

Sano, Kohei; Masuda, Ryo; Hisada, Hayato; Oishi, Shinya; Shimokawa, Kenta; Ono, Masahiro; Fujii, Nobutaka; Saji, Hideo; Mukai, Takahiro

2014-03-01

We have developed a novel radiogallium (Ga)-DOTA-based bivalent peptidic ligand targeting a chemokine receptor, CXCR4, for tumor imaging. A CXCR4 imaging probe with two CXCR4 antagonists (Ac-TZ14011) on Ga-DOTA core, Ga-DOTA-TZ2, was synthesized, and the affinity and binding to CXCR4 was evaluated in CXCR4 expressing cells in vitro. The affinity of Ga-DOTA-TZ2 for CXCR4 was 20-fold greater than the corresponding monovalent probe, Ga-DOTA-TZ1. (67)Ga-DOTA-TZ2 showed the significantly higher accumulation in CXCR4-expressing tumor cells compared with (67)Ga-DOTA-TZ1, suggesting the bivalent effect enhances its binding to CXCR4. The incorporation of two CXCR4 antagonists to Ga-DOTA could be effective in detecting CXCR4-expressing tumors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Managing Zirconium Chemistry and Phase Compatibility in Combined Process Separations for Minor Actinide Partitioning

Energy Technology Data Exchange (ETDEWEB)

Wall, Nathalie [Washington State Univ., Pullman, WA (United States); Nash, Ken [Washington State Univ., Pullman, WA (United States); Martin, Leigh [Washington State Univ., Pullman, WA (United States)

2017-03-17

In response to the NEUP Program Supporting Fuel Cycle R&D Separations and Waste Forms call DEFOA- 0000799, this report describes the results of an R&D project focusing on streamlining separation processes for advanced fuel cycles. An example of such a process relevant to the U.S. DOE FCR&D program would be one combining the functions of the TRUEX process for partitioning of lanthanides and minor actinides from PUREX(UREX) raffinates with that of the TALSPEAK process for separating transplutonium actinides from fission product lanthanides. A fully-developed PUREX(UREX)/TRUEX/TALSPEAK suite would generate actinides as product(s) for reuse (or transmutation) and fission products as waste. As standalone, consecutive unit-operations, TRUEX and TALSPEAK employ different extractant solutions (solvating (CMPO, octyl(phenyl)-N,Ndiisobutylcarbamoylmethylphosphine oxide) vs. cation exchanging (HDEHP, di-2(ethyl)hexylphosphoric acid) extractants), and distinct aqueous phases (2-4 M HNO₃ vs. concentrated pH 3.5 carboxylic acid buffers containing actinide selective chelating agents). The separate processes may also operate with different phase transfer kinetic constraints. Experience teaches (and it has been demonstrated at the lab scale) that, with proper control, multiple process separation systems can operate successfully. However, it is also recognized that considerable economies of scale could be achieved if multiple operations could be merged into a single process based on a combined extractant solvent. The task of accountability of nuclear materials through the process(es) also becomes more robust with fewer steps, providing that the processes can be accurately modeled. Work is underway in the U.S. and Europe on developing several new options for combined processes (TRUSPEAK, ALSEP, SANEX, GANEX, ExAm are examples). There are unique challenges associated with the operation of such processes, some relating to organic phase chemistry, others arising from the

Acyl and silyl group effects in reactivity-based one-pot glycosylation: synthesis of embryonic stem cell surface carbohydrates Lc4 and IV(2)Fuc-Lc4.

Science.gov (United States)

Hsu, Yun; Lu, Xin-An; Zulueta, Medel Manuel L; Tsai, Chih-Ming; Lin, Kuo-I; Hung, Shang-Cheng; Wong, Chi-Huey

2012-03-14

Relative reactivity evaluations showed the graded arming of toluenyl thioglucosides by variously positioned silyl groups but not by their acyl counterparts. These findings were applied in reactivity-based one-pot assembly of linker-attached Lc(4) and IV(2)Fuc-Lc(4), which are components of human embryonic stem cell surface. The sugar-galectin-1 binding was also examined.

All-solid-state lithium-sulfur battery based on a nanoconfined LiBH4 electrolyte

DEFF Research Database (Denmark)

Das, Supti; Ngene, Peter; Norby, Poul

2016-01-01

In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4 in mesoporous silica as solid electrolytes. The nano-confined LiBH4 has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport...... number (t+ = 0.96), close to unity, demonstrates a purely cationic conductor. The electrolyte has an excellent stability against lithium metal. The behavior of the batteries is studied by cyclic voltammetry and repeated charge/discharge cycles in galvanostatic conditions. The batteries show very good...

Programming scheme based optimization of hybrid 4T-2R OxRAM NVSRAM

Science.gov (United States)

Majumdar, Swatilekha; Kingra, Sandeep Kaur; Suri, Manan

2017-09-01

In this paper, we present a novel single-cycle programming scheme for 4T-2R NVSRAM, exploiting pulse engineered input signals. OxRAM devices based on 3 nm thick bi-layer active switching oxide and 90 nm CMOS technology node were used for all simulations. The cell design is implemented for real-time non-volatility rather than last-bit, or power-down non-volatility. Detailed analysis of the proposed single-cycle, parallel RRAM device programming scheme is presented in comparison to the two-cycle sequential RRAM programming used for similar 4T-2R NVSRAM bit-cells. The proposed single-cycle programming scheme coupled with the 4T-2R architecture leads to several benefits such as- possibility of unconventional transistor sizing, 50% lower latency, 20% improvement in SNM and ∼20× reduced energy requirements, when compared against two-cycle programming approach.

Performance Investigation of Automobile Radiator Operated with ZnFe2O4 Nano Fluid based Coolant

Directory of Open Access Journals (Sweden)

Tripathi Ajay

2015-01-01

Full Text Available The cooling system of an Automobile plays an important role in its performance, consists of two main parts, known as radiator and fan. Improving thermal efficiency of engine leads to increase the engine's performance, decline the fuel consumption and decrease the pollution emissions. Water and ethylene glycol as conventional coolants have been widely used in radiators of an automotive industry for many years. These heat transfer fluids offer low thermal conductivity. With the advancement of nanotechnology, the new generation of heat transfer fluids called, “nanofluids” have been developed and researchers found that these fluids offer higher thermal conductivity compared to that of conventional coolants. This study focused on the preparation of Zinc based nanofluids (ZnFe2O4 using chemical co-precipitation method and its application in an automotive cooling system along with mixture of ethylene glycol and water (50:50. Relevant input data, nanofluids properties and empirical correlations were obtained from literatures to investigate the heat transfer enhancement of an automotive car radiator operated with nano fluid-based coolants. It was observed that, overall heat transfer coefficient and heat transfer rate in engine cooling system increased with the usage of nanofluids (with ethylene glycol the base-fluid compared to ethylene glycol (i.e. base-fluid alone. It is observed that, about 78% of heat transfer enhancement could be achieved with the addition of 1% ZnFe2O4 particles in a base fluid at the Reynolds number of 84.4x103 and 39.5x103 for air and coolant respectively

Conductivity studies of biopolymer electrolytes based on chitosan incorporated with NH4Br

International Nuclear Information System (INIS)

Shukur, M F; Azmi, M S; Zawawi, S M M; Majid, N A; Illias, H A; Kadir, M F Z

2013-01-01

A polymer electrolyte system based on chitosan complexed with ammonium bromide (NH 4 Br) salt was prepared by the solution cast technique. 30 wt% NH 4 Br added electrolyte gave a room temperature conductivity of (4.38 ± 1.26) × 10 −7  S cm −1 and increased to (2.15 ± 0.47) × 10 −4  S cm −1 with addition of 40 wt% glycerol. The dependence of the conductivity on temperature proves that both chitosan–NH 4 Br and chitosan–NH 4 Br–glycerol systems are Arrhenian. The activation energy (E a ) value for 70 wt% chitosan–30 wt% NH 4 Br film is 0.31 eV and the E a value for 42 wt% chitosan–18 wt% NH 4 Br–40 wt% glycerol film is 0.20 eV. The carboxamide band at 1640 cm −1 and the amine band at 1549 cm −1 in the spectrum of pure chitosan film shifted to 1617 and 1516 cm −1 , respectively, in the spectrum of 70 wt% chitosan–30 wt% NH 4 Br film, indicating the occurrence of complexation between polymer and salt. The band at 1024 cm −1 in the pure chitosan film spectrum, which corresponds to the C–O stretching vibration, shifted to lower wavenumbers on addition of salt. A new band appears at 997 cm −1 on addition of 40 wt% glycerol. (paper)

Selective isolation of gonyautoxins 1,4 from the dinoflagellate Alexandrium minutum based on molecularly imprinted solid-phase extraction.

Science.gov (United States)

Lian, Ziru; Wang, Jiangtao

2017-09-15

Gonyautoxins 1,4 (GTX1,4) from Alexandrium minutum samples were isolated selectively and recognized specifically by an innovative and effective extraction procedure based on molecular imprinting technology. Novel molecularly imprinted polymer microspheres (MIPMs) were prepared by double-templated imprinting strategy using caffeine and pentoxifylline as dummy templates. The synthesized polymers displayed good affinity to GTX1,4 and were applied as sorbents. Further, an off-line molecularly imprinted solid-phase extraction (MISPE) protocol was optimized and an effective approach based on the MISPE coupled with HPLC-FLD was developed for selective isolation of GTX1,4 from the cultured A. minutum samples. The separation method showed good extraction efficiency (73.2-81.5%) for GTX1,4 and efficient removal of interferences matrices was also achieved after the MISPE process for the microalgal samples. The outcome demonstrated the superiority and great potential of the MISPE procedure for direct separation of GTX1,4 from marine microalgal extracts. Copyright © 2017. Published by Elsevier Ltd.

Assessment of simulated and projected climate change in Pakistan using IPCC AR4-based AOGCMs

Science.gov (United States)

Saeed, F.; Athar, H.

2017-11-01

A detailed spatio-temporal assessment of two basic climatic parameters (temperature and precipitation) is carried out using 22 Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4)-based atmospheric oceanic general circulation models (AOGCMs) over data-sparse and climatically vulnerable region of Pakistan (20°-37° N and 60°-78° E), for the first time, for the baseline period (1975-1999), as well as for the three projected periods during the twenty-first century centered at 2025-2049, 2050-2074, and 2075-2099, respectively, both on seasonal and on annual bases, under three Special Report on Emission Scenarios (SRES): A2, A1B, and B1. An ensemble-based approach consisting of the IPCC AR4-based AOGCMs indicates that during the winter season (from December to March), 66% of the models display robust projected increase of winter precipitation by about 10% relative to the baseline period, irrespective of emission scenario and projection period, in the upper northern subregion of Pakistan (latitude > 35° N). The projected robust changes in the temperature by the end of twenty-first century are in the range of 3 to 4 ° C during the winter season and on an annual basis, in the central and western regions of Punjab province, especially in A2 and A1B emission scenarios. In particular, the IPCC AR4 models project a progressive increase in temperature throughout Pakistan, in contrast to spatial distribution of precipitation, where spatially less uniform and robust results for projected periods are obtained on sign of change. In general, changes in both precipitation and temperature are larger in the summer season (JAS) as compared to the winter season in the coming decades, relative to the baseline period. This may require comprehensive long-term strategic policies to adapt and mitigate climate change in Pakistan, in comparison to what is currently envisaged.

Serotonin transporter activity of imidazolidine-2,4-dione and imidazo[2,1-f]purine-2,4-dione derivatives in aspect of their acid-base properties.

Science.gov (United States)

Zagórska, Agnieszka; Czopek, Anna; Pawłowski, Maciej; Dybała, Małgorzata; Siwek, Agata; Nowak, Gabriel

2012-11-01

Affinities of arylpiperazinylalkyl derivatives of imidazo[2,1-f]purine-2,4-dione and imidazolidine-2,4-dione for serotonin transporter and their acid-base properties were evaluated. The dissociation constant (pK(a)) of compounds 1-22 were determinated by potentiometric titration and calculated using pKalc 3.1 module of the Pallas system. The data from experimental methods and computational calculations were compared and suitable conclusions were reached.

Role of TiF4 in Microleakage of Silorane and Methacrylate-based Composite Resins in Class V Cavities.

Science.gov (United States)

Koohpeima, Fatemeh; Sharafeddin, Farahnaz; Jowkar, Zahra; Ahmadzadeh, Samaneh; Mokhtari, Mohammad Javad; Azarian, Babak

2016-03-01

This study investigated the effect of TiF4 solution pretreat-ment on microleakage of silorane and nanofilled methacrylate-based composites in class V cavities. Forty-eight intact premolar teeth were randomly allocated to four groups of 12 teeth. Restorative techniques after standard class V tooth preparations were as follows: Group 1, Filtek P90 composite; group 2, Filtek Z350 XT; group 3, TiF4 solution pretreatment and Filtek P90 composite; group 4, TiF4 solution pretreatment and Filtek Z350 XT. After storing the specimens in distilled water at 37°C for 24 hours and followed by immersion of the specimens in a 0.5% basic-fuchsin solution for 24 hours, they were sectioned buccolingually to obtain four surfaces for each specimen for analysis of microleakage using a stereomicroscope. Data analysis was performed using Kruskal-Wallis test to compare the four groups and the Mann-Whitney test for paired comparisons with Statistical Package for the Social Sciences (SPSS) version 17 software. At the enamel margins, microleakage score of the Filtek Z350 XT group was lower than those of the Filtek P90 with and without the application of the TiF4 (p = 0.009 and p = 0.031 respectively). At the dentin margins, groups 3 and 4 (TiF4+Filtek P90 and TiF4+Filtek z350 XT respectively) showed significantly lower microleakage than group 1 (Filtek P90). However, there was no significant difference between other groups (p > 0.05). At the enamel margins, microleakage score of the silorane-based composite was more than that of the nanofilled composite. No significant differences were observed between the other groups. At the dentin margins, for the silorane-based composite restorations, TiF4 solution pretreatment resulted in significantly lower microleakage. However, the similar result was not observed for Filtek Z350 XT. Also, no significant difference was observed between microleakage scores of Filtek P90 and Filtek Z350 XT with or without TiF4 pretreatment. In spite of better mechanical

Preparations, structures and properties of heterobimetallic complexes based on tetrahydrofuran-2,3,4,5-tetracarboxylate

Energy Technology Data Exchange (ETDEWEB)

Jia, Tian-Jing; Li, Shu-Mu; Cao, Wei [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Li, Li-Cun [College of Chemistry, Nankai University, Tianjin 300071 (China); Zheng, Xiang-Jun, E-mail: xjzheng@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Yuan, Da-Qiang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2013-05-01

Transition heterobimetallic metal-organic frameworks based on tetrahydrofuran-2,3,4,5-tetracarboxylicate (FTA), namely [M(H₂O)₆][Cu₂M(FTA)₂(H₂O)₂]·4H₂O [M=Mn (1), Co (2)], and [CuZn(FTA)(H₂O)₅]·H₂O (3) have been synthesized and characterized. Single-crystal X-ray diffraction indicates that complexes 1 and 2 are isomorphic. In 1 and 2, FTA ligand links the metal ions to a 2-D wave-like negative-charged layer with a topology of (4;6²)₂(4;6³;8²)₂(6). They possess 1-D channels with [M(H₂O)₆]²⁺ and lattice water molecules enclathrated. While in the complex 3, Cu²⁺ and Zn²⁺ ions are bridged by FTA to a 2-D neutral layer structure with a (8)₂(8⁴;12²) topology. Magnetic properties of 1–3 were analyzed in connection with their structures, which show that there exist weak antiferromagnetic interactions between metal ions. - Graphical abstract: Three heterobimetallic MOFs were constructed through the size-selectivity of TFA coordination sites for different transition metal ions based on the concept of “Hard and Soft Acids and Bases”. Highlights: • Complexes 1 and 3 contain 2-D wave-like negative-charged layers. • Complex 2 is a 2-D neutral layer structure with a (8)₂(8⁴;12²) topology. • Complexes 1–3 are the first example of heterobimetallic MOFs based on FTA. • The coordination sites of FTA show size-selectivity to metal ions.

Solution based synthesis of mixed-phase materials in the Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} system

Energy Technology Data Exchange (ETDEWEB)

Hanaor, Dorian A.H., E-mail: dorian.hanaor@sydney.edu.au [School of Civil Engineering, University of Sydney, NSW 2006 (Australia); Kolb, Matthias H.H. [Institute for Applied Materials, Karlsruhe Institute of Technology, 76021 (Germany); Gan, Yixiang [School of Civil Engineering, University of Sydney, NSW 2006 (Australia); Kamlah, Marc; Knitter, Regina [Institute for Applied Materials, Karlsruhe Institute of Technology, 76021 (Germany)

2015-01-15

Highlights: • Investigation of phase stability in the quasi-binary Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} system. • Sol-based syntheses of mixed phase materials from organometallic precursors. • LiCl based synthesis results in greater lithium deficiency than LiOH synthesis. • The Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} quasi binary system appears to exhibit monotectic behaviour. • Mixed phase materials show liquid formation from melting of silicate material at 1100 °C. - Abstract: As candidate tritium breeder materials for use in the ITER helium cooled pebble bed, ceramic multiphasic compounds lying in the region of the quasi-binary lithium metatitanate–lithium orthosilicate system may exhibit mechanical and physical advantages relative to single phase materials. Here we present an organometallic solution-based synthesis procedure for the low-temperature fabrication of compounds in the Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} region and investigate phase stability and transformations through temperature varied X-ray diffraction and scanning calorimetry. Results demonstrate that the metatitanate and metasilicate phases Li{sub 2}TiO{sub 3} and Li{sub 2}SiO{sub 3} readily crystallise in nanocrystalline form at temperatures below 180 °C. Lithium deficiency in the region of 5% results from Li sublimation from Li{sub 4}SiO{sub 4} and/or from excess Li incorporation in the metatitanate phase and brings about a stoichiometry shift, with product compounds exhibiting mixed lithium orthosilicate/metasilicate content towards the Si rich region and predominantly Li{sub 2}TiO{sub 3} content towards the Ti rich region. Above 1150 °C the transformation of monoclinic to cubic γ-Li{sub 2}TiO{sub 3} disordered solid-solution occurs while the melting of silicate phases indicates a likely monotectic type system with a solidus line in the region 1050–1100 °C. Synthesis procedures involving a lithium chloride precursor are not likely to be a viable option for

Acid-base chemistry and proton conductivity of CsHSO₄, CsH₂PO₄ and their mixtures with N-heterocycles  

DEFF Research Database (Denmark)

Aili, David; Gao, Ying; Han, Junyoung

2017-01-01

temperature range of CsH2PO4 as well. Binary mixtures of CsH2PO4 with 1,2,4-triazole, benzimidazole or imidazole were prepared by means of mechanochemical synthesis. Mixtures based on CsHSO4 were prepared as a basis for a comparative discussion. It was found that CsHSO4 formed organic-inorganic salts, while...

Simple, Scalable, Script-based, Science Processor for Measurements - Data Mining Edition (S4PM-DME)

Science.gov (United States)

Pham, L. B.; Eng, E. K.; Lynnes, C. S.; Berrick, S. W.; Vollmer, B. E.

2005-12-01

The S4PM-DME is the Goddard Earth Sciences Distributed Active Archive Center's (GES DAAC) web-based data mining environment. The S4PM-DME replaces the Near-line Archive Data Mining (NADM) system with a better web environment and a richer set of production rules. S4PM-DME enables registered users to submit and execute custom data mining algorithms. The S4PM-DME system uses the GES DAAC developed Simple Scalable Script-based Science Processor for Measurements (S4PM) to automate tasks and perform the actual data processing. A web interface allows the user to access the S4PM-DME system. The user first develops personalized data mining algorithm on his/her home platform and then uploads them to the S4PM-DME system. Algorithms in C and FORTRAN languages are currently supported. The user developed algorithm is automatically audited for any potential security problems before it is installed within the S4PM-DME system and made available to the user. Once the algorithm has been installed the user can promote the algorithm to the "operational" environment. From here the user can search and order the data available in the GES DAAC archive for his/her science algorithm. The user can also set up a processing subscription. The subscription will automatically process new data as it becomes available in the GES DAAC archive. The generated mined data products are then made available for FTP pickup. The benefits of using S4PM-DME are 1) to decrease the downloading time it typically takes a user to transfer the GES DAAC data to his/her system thus off-load the heavy network traffic, 2) to free-up the load on their system, and last 3) to utilize the rich and abundance ocean, atmosphere data from the MODIS and AIRS instruments available from the GES DAAC.

Tenofovir-Based Highly Active Antiretroviral Therapy Is Associated with Superior CD4 T Cells Repopulation Compared to Zidovudine-Based HAART in HIV 1 Infected Adults

Directory of Open Access Journals (Sweden)

Vitus Sambo Badii

2018-01-01

Full Text Available Tenofovir-based highly active antiretroviral therapy (HAART is one of the preferred first-line therapies in the management of HIV 1 infection. Ghana has since 2014 adopted this recommendation; however there is paucity of scientific data that reflects the safety and efficacy of the tenofovir-based therapy compared to zidovudine in the Ghanaian health system. This study sought to assess the comparative immune reconstitution potential between tenofovir and zidovudine-based HAART regimens, which includes lamivudine and efavirenz in combination therapy. It also aimed to investigate the adverse drug reactions/events (ADREs associated with pharmacotherapy with these agents in a total of 106 HAART naïve HIV patients. The study included 80 patients in the tenofovir cohort while 26 patients were on the zidovudine regimen. The occurrence of HIV comorbidities profile was assessed at diagnosis and throughout the study period. The baseline CD4 T cells count of the participants was also assessed at diagnosis and repeated at a median period of five months (range 4–6 months, after commencing treatment with either tenofovir- or zidovudine-based HAART. After five months of the HAART, the tenofovir cohort recorded higher CD4 T cell count change from baseline compared to the zidovudine cohort (p<0.0001. The patients on the tenofovir-based HAART and female sex however appeared to be associated with more multiple ADREs.

Cycling Performance of Li4Ti5O12 Electrodes in Ionic Liquid-Based Gel Polymer Electrolytes

International Nuclear Information System (INIS)

Kim, Jin Hee; Kim, Dong Won; Kang, Yong Ku

2012-01-01

We investigated the cycling behavior of Li 4 Ti 5 O 12 electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The Li 4 Ti 5 O 12 electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %

All-dielectric KTiOPO4 metasurfaces based on multipolar resonances in the terahertz region

DEFF Research Database (Denmark)

Tian, Jingyi; Yang, Yuanqing; Qiu, Min

2017-01-01

We employ ferroelectrics to study the multipolar scattering in all-dielectric metasurfaces based on KTiOPO4 (KTP) micro-disks for efficient manipulation of electromagnetic waves in the THz spectral region (0.6-1.5 THz). By adjusting the aspect ratio of the disks near the multipolar resonances, we...

An overview on the research of Sr2IrO4-based system probed by X-ray absorption spectroscopy

Science.gov (United States)

Cheng, Jie; Zhu, Chaomin; Ma, Jingyuan; Wang, Yu; Liu, Shengli

2018-03-01

Investigations of materials with 5d transition metal ions have opened up new paradigms in condensed-matter physics because of their large spin-orbit coupling (SOC) interactions. The typical compound is Sr2IrO4, which attracted much attention due to its similarities to the parent compound of high-Tc cuprate superconductor La2CuO4. Theoretical calculations predicted that the unconventional superconductivity can occur in carrier doped-Sr2IrO4 system. Until now, hundreds of experimental methods were devoted to investigate the carrier doping effect on Sr2IrO4. Synchrotron radiation-based X-ray absorption spectroscopy (XAS) made great contributions to the local lattice and electronic structure, and also the intimate relationship between the local structure and physical properties induced by carrier doping. The aim of this review is a short introduction to the progress of research on Sr2IrO4-based system probed by the unique technique — XAS, including the strength of the SOC, valence changes upon doping and even local lattice structure with atomic level for this Sr2IrO4-based family.

A novel extended architecture with 4 6·6 4 topology based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units

Science.gov (United States)

Tong, Ruizhan; Ren, Xiaoyu; Li, Zuoxi; Liu, Bin; Hu, Huaiming; Xue, Ganglin; Fu, Feng; Wang, Jiwu

2010-09-01

A novel inorganic-organic hybrid compound based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units, Cu 8I(imi) 4(bpy) 6(H 2O)[As 2VW 2VW 16VlO 62]·2H 2O ( 1) (bpy=4,4'-bipydine; imi=imidazole), has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, luminescent spectrum and single crystal X-ray diffraction. Single-crystal X-ray diffraction revealed that four terminal and three bridging oxygen atoms of the Wells-Dawson cluster are coordinated to Cu(I) ions and form an unprecedented hepta-supporting polyoxometalate. The functionalized arsenotungstates are further connected by two kinds of tridentate linkers, Imi-Cu-(bpy)-Cu-(bpy)-Cu-(bpy)-Cu-Imi and Imi-Cu-(bpy)-Cu-(bpy)-Cu-H 2O, to construct a 3D framework with 4 6·6 4 topology. The hybrid material has an intense emission at about 397 nm.

BIM-Based 4D Simulation to Improve Module Manufacturing Productivity for Sustainable Building Projects

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Joosung Lee

2017-03-01

Full Text Available Modular construction methods, where products are manufactured beforehand in a factory and then transported to the site for installation, are becoming increasingly popular for construction projects in many countries as this method facilitates the use of the advanced technologies that support sustainability in building projects. This approach requires dual factory–site process management to be carefully coordinated and the factory module manufacturing process must therefore be managed in a detailed and quantitative manner. However, currently, the limited algorithms available to support this process are based on mathematical methodologies that do not consider the complex mix of equipment, factories, personnel, and materials involved. This paper presents three new building information modeling-based 4D simulation frameworks to manage the three elements—process, quantity, and quality—that determine the productivity of factory module manufacturing. These frameworks leverage the advantages of 4D simulation and provide more precise information than existing conventional documents. By utilizing a 4D model that facilitates the visualization of a wide range of data variables, manufacturers can plan the module manufacturing process in detail and fully understand the material, equipment, and workflow needed to accomplish the manufacturing tasks. Managers can also access information about material quantities for each process and use this information for earned value management, warehousing/storage, fabrication, and assembly planning. By having a 4D view that connects 2D drawing models, manufacturing errors and rework can be minimized and problems such as construction delays, quality lapses, and cost overruns vastly reduced.

The influence of reduced graphene oxide on electrical conductivity of LiFePO{sub 4}-based composite as cathode material

Energy Technology Data Exchange (ETDEWEB)

Arifin, Muhammad; Aimon, Akfiny Hasdi; Winata, Toto; Abdullah, Mikrajuddin [Physics of Electronic Materials Research Division, Department of Physics, Institut Teknologi Bandung, Bandung 40132 Indonesia (Indonesia); Iskandar, Ferry, E-mail: ferry@fi.itb.ac.id [Physics of Electronic Materials Research Division, Department of Physics, Institut Teknologi Bandung, Bandung 40132 Indonesia (Indonesia); Research Center for Nanoscience and Nanotechnology Institut Teknologi Bandung, Bandung 40132 Indonesia (Indonesia)

2016-02-08

LiFePO{sub 4} is fascinating cathode active materials for Li-ion batteries application because of their high electrochemical performance such as a stable voltage at 3.45 V and high specific capacity at 170 mAh.g{sup −1}. However, their low intrinsic electronic conductivity and low ionic diffusion are still the hindrance for their further application on Li-ion batteries. Therefore, the efforts to improve their conductivity are very important to elevate their prospecting application as cathode materials. Herein, we reported preparation of additional of reduced Graphene Oxide (rGO) into LiFePO{sub 4}-based composite via hydrothermal method and the influence of rGO on electrical conductivity of LiFePO{sub 4}−based composite by varying mass of rGO in composition. Vibration of LiFePO{sub 4}-based composite was detected on Fourier Transform Infrared Spectroscopy (FTIR) spectra, while single phase of LiFePO{sub 4} nanocrystal was observed on X-Ray Diffraction (XRD) pattern, it furthermore, Scanning Electron Microscopy (SEM) images showed that rGO was distributed around LiFePO4-based composite. Finally, the 4-point probe measurement result confirmed that the optimum electrical conductivity is in additional 2 wt% rGO for range 1 to 2 wt% rGO.

Automatic markerless registration of point clouds with semantic-keypoint-based 4-points congruent sets

Science.gov (United States)

Ge, Xuming

2017-08-01

The coarse registration of point clouds from urban building scenes has become a key topic in applications of terrestrial laser scanning technology. Sampling-based algorithms in the random sample consensus (RANSAC) model have emerged as mainstream solutions to address coarse registration problems. In this paper, we propose a novel combined solution to automatically align two markerless point clouds from building scenes. Firstly, the method segments non-ground points from ground points. Secondly, the proposed method detects feature points from each cross section and then obtains semantic keypoints by connecting feature points with specific rules. Finally, the detected semantic keypoints from two point clouds act as inputs to a modified 4PCS algorithm. Examples are presented and the results compared with those of K-4PCS to demonstrate the main contributions of the proposed method, which are the extension of the original 4PCS to handle heavy datasets and the use of semantic keypoints to improve K-4PCS in relation to registration accuracy and computational efficiency.

Mesenchymal stem cell-based NK4 gene therapy in nude mice bearing gastric cancer xenografts

Directory of Open Access Journals (Sweden)

Zhu Y

2014-12-01

tissues after systemic injection. The microvessel density of tumor xenografts was decreased, and tumor cellular apoptosis was significantly induced in the mice treated with MSCs-NK4 compared to control mice. These findings demonstrate that MSC-based NK4 gene therapy can obviously inhibit the growth of gastric cancer xenografts, and MSCs are a better vehicle for NK4 gene therapy than lentiviral vectors. Further studies are warranted to explore the efficacy and safety of the MSC-based NK4 gene therapy in animals and cancer patients.Keywords: gastric cancer, gene therapy, tumor xenograft, hepatocyte growth factor, lentivirus, angiogenesis, apoptosis

Micro-structured electrochromic device based on poly(3,4-ethylenedioxythiophene)

International Nuclear Information System (INIS)

Deutschmann, T; Oesterschulze, E

2013-01-01

Recent developments in consumer electronics, e.g. smartphones, tablet PCs or compact cameras, demand the development of very compact, active, optical microsystems. Because of their low power consumption, low operation voltage and cheap fabrication, voltage-controlled electrochromic devices (ECDs) based on polymer materials are promising candidates. However, the broad application of ECDs is still hindered by crucial technological obstacles. In this paper, we address two main issues: the structuring of the electrochromic material (ECM) and its underlying transparent conductive electrode on a microscale and additionally, the assembly of the ECD as an electrochemical cell with the challenges of airtight sealing, appropriate chemical stability, electrical insulation and the necessity of defining a compartment to hold the liquid electrolyte inside the cell. We first introduce a technological sequence consisting of batch processes (UV lithography and dry and wet etching) to render the microscale structuring of the ECM possible. Furthermore, we exploit the outstanding properties of the thick film dry photoresist Ordyl SY 300 to complete the assembly of ECDs with single-layer technology. As a proof of principle, we present the first results of an ECD device based on a poly(3,4-ethylenedioxythiophene) (PEDOT) material that works as an aperture stop with three coaxial segments, each individually controlled by an external voltage. (paper)

Mapping pan-Arctic CH4 emissions using an adjoint method by integrating process-based wetland and lake biogeochemical models and atmospheric CH4 concentrations

Science.gov (United States)

Tan, Z.; Zhuang, Q.; Henze, D. K.; Frankenberg, C.; Dlugokencky, E. J.; Sweeney, C.; Turner, A. J.

2015-12-01

Understanding CH4 emissions from wetlands and lakes are critical for the estimation of Arctic carbon balance under fast warming climatic conditions. To date, our knowledge about these two CH4 sources is almost solely built on the upscaling of discontinuous measurements in limited areas to the whole region. Many studies indicated that, the controls of CH4 emissions from wetlands and lakes including soil moisture, lake morphology and substrate content and quality are notoriously heterogeneous, thus the accuracy of those simple estimates could be questionable. Here we apply a high spatial resolution atmospheric inverse model (nested-grid GEOS-Chem Adjoint) over the Arctic by integrating SCIAMACHY and NOAA/ESRL CH4 measurements to constrain the CH4 emissions estimated with process-based wetland and lake biogeochemical models. Our modeling experiments using different wetland CH4 emission schemes and satellite and surface measurements show that the total amount of CH4 emitted from the Arctic wetlands is well constrained, but the spatial distribution of CH4 emissions is sensitive to priors. For CH4 emissions from lakes, our high-resolution inversion shows that the models overestimate CH4 emissions in Alaskan costal lowlands and East Siberian lowlands. Our study also indicates that the precision and coverage of measurements need to be improved to achieve more accurate high-resolution estimates.

Secure communications of CAP-4 and OOK signals over MMF based on electro-optic chaos.

Science.gov (United States)

Ai, Jianzhou; Wang, Lulu; Wang, Jian

2017-09-15

Chaos-based secure communication can provide a high level of privacy in data transmission. Here, we experimentally demonstrate secure signal transmission over two kinds of multimode fiber (MMF) based on electro-optic intensity chaos. High-quality synchronization is achieved in an electro-optic feedback configuration. Both 5  Gbit/s carrier-less amplitude/phase (CAP-4) modulation and 10  Gbit/s on-off key (OOK) signals are recovered efficiently in electro-optic chaos-based communication systems. Degradations of chaos synchronization and communication system due to mismatch of various hardware keys are also discussed.

Mechanical and Thermal Properties of Palm-Based Polyurethane Composites Filled with Fe3O4, PANI and PANI/ Fe3O4

International Nuclear Information System (INIS)

Hao, L.C.; Sahrim Ahmad; Khairiah Badri

2011-01-01

In-situ polymerization method was used to prepare palm-based polyurethane (PU) composites loading with 15 wt % magnetite (Fe 3 O 4 ), poly aniline (PANI) and Fe 3 O 4 coated with PANI labeled as PU15, PP and PPM, respectively. FTIR spectroscopy analysis indicated a shift in the carbonyl, C=O and NH in PP. The shift of the peak indicated that there was hydrogen bonding between the C=O (proton acceptor) of urethane with NH (proton-donator) of PANI. PPM gave the highest impact and flexural strengths at 4875 kJ/ m 2 and 42 MPa, respectively but with the lowest flexural modulus (1050 MPa). Two-stage degradation behavior was observed in the TGA thermo gram. (author)

Fe3O4@HKUST-1 and Pd/Fe3O4@ HKUST-1 as magnetically recyclable catalysts prepared via conversion from a Cu-based ceramic

OpenAIRE

Toyao, Takashi; Styles, Mark J.; Yago, Tokuichiro; Sadiq, Muhammad M.; Ricco, Raffaele; Suzuki, Kiyonori; Horiuchi, Yu; Takahashi, Masahide; Matsuoka, Masaya; Falcaro, Paolo

2017-01-01

Nanocomposites obtained by integrating iron oxide magnetic nanoparticles (Fe3O4) into a metal-organic framework (HKUST-1 or Cu-3(BTC)(2), BTC = 1,3,5-benzenetricarboxylate) are synthesized through conversion from a composite of a Cu-based ceramic material and Fe3O4. In situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements reveal that the presence of Fe3O4 leads to the fast conversion and synthesis of HKUST-1 with small particle sizes. The prepared MOF co...

Protein structure modelling and evaluation based on a 4-distance description of side-chain interactions

Directory of Open Access Journals (Sweden)

Inbar Yuval

2010-07-01

Full Text Available Abstract Background Accurate evaluation and modelling of residue-residue interactions within and between proteins is a key aspect of computational structure prediction including homology modelling, protein-protein docking, refinement of low-resolution structures, and computational protein design. Results Here we introduce a method for accurate protein structure modelling and evaluation based on a novel 4-distance description of residue-residue interaction geometry. Statistical 4-distance preferences were extracted from high-resolution protein structures and were used as a basis for a knowledge-based potential, called Hunter. We demonstrate that 4-distance description of side chain interactions can be used reliably to discriminate the native structure from a set of decoys. Hunter ranked the native structure as the top one in 217 out of 220 high-resolution decoy sets, in 25 out of 28 "Decoys 'R' Us" decoy sets and in 24 out of 27 high-resolution CASP7/8 decoy sets. The same concept was applied to side chain modelling in protein structures. On a set of very high-resolution protein structures the average RMSD was 1.47 Å for all residues and 0.73 Å for buried residues, which is in the range of attainable accuracy for a model. Finally, we show that Hunter performs as good or better than other top methods in homology modelling based on results from the CASP7 experiment. The supporting web site http://bioinfo.weizmann.ac.il/hunter/ was developed to enable the use of Hunter and for visualization and interactive exploration of 4-distance distributions. Conclusions Our results suggest that Hunter can be used as a tool for evaluation and for accurate modelling of residue-residue interactions in protein structures. The same methodology is applicable to other areas involving high-resolution modelling of biomolecules.

Synthesis and antimalarial evaluation of some 4-quinazolinone derivatives based on febrifugine

Directory of Open Access Journals (Sweden)

Debanjan Sen

2010-01-01

Full Text Available A series of 2-substituted and 2,3-substituted quinazolin -4(3H-one derivatives were designed and synthesized based on the structure of febrifugine. The structures of the new compounds were confirmed by spectral analysis. The in vivo biological activity test results indicated that those compounds exhibited antimalarial activities against Plasmodium berghei in mice, at a dose of 5 mg/kg. Compared to Chloroquine and Artemisinin, these compounds have the advantages of shorter synthetic routes and consequently are highly cost effective in nature.

Selective fluorescence response and magnetic separation probe for 2,4,6-trinitrotoluene based on iron oxide magnetic nanoparticles.

Science.gov (United States)

Zou, Wen-Sheng; Wang, Ya-Qin; Wang, Feng; Shao, Qun; Zhang, Jun; Liu, Jin

2013-05-01

Despite the rapid development of nanomaterials and nanotechnology, it is still desirable to develop novel nanoparticle-based techniques which are cost-effective, timesaving, and environment-friendly, and with ease of operation and procedural simplicity, for assay of target analytes. In the work discussed in this paper, the dye fluorescein isothiocyanate (FITC) was conjugated to 1,6-hexanediamine (HDA)-capped iron oxide magnetic nanoparticles (FITC-HDA Fe3O4 MNPs), and the product was characterized. HDA ligands on the surface of Fe3O4 MNPs can bind 2,4,6-trinitrotoluene (TNT) to form TNT anions by acid-base pairing interaction. Formation of TNT anions, and captured TNT substantially affect the emission of FITC on the surface of the Fe3O4 MNPs, resulting in quenching of the fluorescence at 519 nm. A novel FITC-HDA Fe3O4 MNPs-based probe featuring chemosensing and magnetic separation has therefore been constructed. i.e. FITC-HDA Fe3O4 MNPs had a highly selective fluorescence response and enabled magnetic separation of TNT from other nitroaromatic compounds by quenching of the emission of FITC and capture of TNT in aqueous solution. Very good linearity was observed for TNT concentrations in the range 0.05-1.5 μmol L(-1), with a detection limit of 37.2 nmol L(-1) and RSD of 4.7 % (n = 7). Approximately 12 % of the total amount of TNT was captured. The proposed methods are well-suited to trace detection and capture of TNT in aqueous solution.

MPEG-4 solutions for virtualizing RDP-based applications

Science.gov (United States)

Joveski, Bojan; Mitrea, Mihai; Ganji, Rama-Rao

2014-02-01

The present paper provides the proof-of-concepts for the use of the MPEG-4 multimedia scene representations (BiFS and LASeR) as a virtualization tool for RDP-based applications (e.g. MS Windows applications). Two main applicative benefits are thus granted. First, any legacy application can be virtualized without additional programming effort. Second, heterogeneous mobile devices (different manufacturers, OS) can collaboratively enjoy full multimedia experiences. From the methodological point of view, the main novelty consists in (1) designing an architecture allowing the conversion of the RDP content into a semantic multimedia scene-graph and its subsequent rendering on the client and (2) providing the underlying scene graph management and interactivity tools. Experiments consider 5 users and two RDP applications (MS Word and Internet Explorer), and benchmark our solution against two state-of-the-art technologies (VNC and FreeRDP). The visual quality is evaluated by six objective measures (e.g. PSNRVNC by a factor 1.8 while being 2 times heavier then the FreeRDP; (2) for Internet browsing, the MPEG solutions outperform both VNC and FreeRDP by factors of 1.9 and 1.5, respectively. The average round-trip times (less than 40ms) cope with real-time application constraints.

Enhanced spin accumulation in Fe3O4 based spin injection devices below the Verwey transition

Science.gov (United States)

Bhat, Shwetha G.; Kumar, P. S. Anil

2016-12-01

Spin injection into GaAs and Si (both n and p-type) semiconductors using Fe3O4 is achieved with and without a tunnel barrier (MgO) via three-terminal electrical Hanle measurement. Interestingly, the magnitude of spin accumulation voltage (ΔV) in semiconductor is found to be associated with a drastic increment in ΔV in Fe3O4 based devices for temperature metal-to-insulator transition of Fe3O4 at T V. Observations from our elaborate investigations show that spin polarization of Fe3O4 has an explicit influence on the enhanced spin injection. It is argued that the theoretical prediction of half-metallicity of Fe3O4 above and below T V has to be reinvestigated.

Electrochemical Determination of Paracetamol Using Fe3O4/Reduced Graphene-Oxide-Based Electrode

Directory of Open Access Journals (Sweden)

Nguyen Thi Anh Thu

2018-01-01

Full Text Available The synthesis of magnetic iron oxide/reduced graphene oxide (Fe3O4/rGO and its application to the electrochemical determination of paracetamol using Fe3O4/rGO modified electrode were demonstrated. The obtained materials were characterized by means of X-ray diffraction (XRD, nitrogen adsorption/desorption isotherms, X-ray photoelectron spectroscopy (XPS, transmission electron microscope (TEM, Fourier transform infrared spectroscopy (FTIR, and magnetic measurement. The results showed that Fe3O4/rGO composite exhibited high specific surface area, and its morphology consists of very fine spherical particles of Fe3O4 in nanoscales. Fe3O4/rGO was used as an electrode modifier for the determination of paracetamol by differential pulse-anodic stripping voltammetry (DP-ASV. The preparation of Fe3O4/rGO-based electrode and some factors affecting voltammetric responses were investigated. The results showed that Fe3O4/rGO is a potential electrode modifier for paracetamol detection by DP-ASV with a low limit of detection. The interfering effect of uric acid, ascorbic acid, and dopamine on the current response of paracetamol has been reported. The repeatability, reproducibility, linear range, and limit of detection were also addressed. The proposed method could be applied to the real samples with satisfactory results.

Wide Band-Gap 3,4-Difluorothiophene-Based Polymer with 7% Solar Cell Efficiency: an Alternative to P3HT

KAUST Repository

Wolf, Jannic Sebastian; Cruciani, Federico; El Labban, Abdulrahman; Beaujuge, Pierre

2015-01-01

We report on a wide band-gap polymer donor composed of benzo[1,2-b:4,5-b']dithiophene (BDT) and 3,4-difluorothiophene ([2F]T) units (Eopt ~2.1 eV), and show that the fluorinated analog PBDT[2F]T performs significantly better than its non-fluorinated counterpart PBDT[2H]T in BHJ solar cells with PC71BM. While control P3HT- and PBDT[2H]T-based devices yield PCEs of ca. 4% and 3% (Max.) respectively, PBDT[2F]T-based devices reach PCEs of ca. 7%, combining a large Voc of ca. 0.9 V and short-circuit current values (ca. 10.7 mA/cm2) comparable to those of the best P3HT-based control devices.

Wide Band-Gap 3,4-Difluorothiophene-Based Polymer with 7% Solar Cell Efficiency: an Alternative to P3HT

KAUST Repository

Wolf, Jannic Sebastian

2015-05-27

We report on a wide band-gap polymer donor composed of benzo[1,2-b:4,5-b\\']dithiophene (BDT) and 3,4-difluorothiophene ([2F]T) units (Eopt ~2.1 eV), and show that the fluorinated analog PBDT[2F]T performs significantly better than its non-fluorinated counterpart PBDT[2H]T in BHJ solar cells with PC71BM. While control P3HT- and PBDT[2H]T-based devices yield PCEs of ca. 4% and 3% (Max.) respectively, PBDT[2F]T-based devices reach PCEs of ca. 7%, combining a large Voc of ca. 0.9 V and short-circuit current values (ca. 10.7 mA/cm2) comparable to those of the best P3HT-based control devices.

TM grating coupler on low-loss LPCVD based Si3N4 waveguide platform

Science.gov (United States)

Dabos, G.; Manolis, A.; Giesecke, A. L.; Porschatis, C.; Chmielak, B.; Wahlbrink, T.; Pleros, N.; Tsiokos, D.

2017-12-01

We demonstrate, for the first time to our knowledge, a fully etched TM grating coupler for low-loss Low-Pressure-Chemical-Vapor-Deposition (LPCVD) based silicon nitride platform with a coupling loss of 6.5 dB at 1541 nm and a 1 dB bandwidth of 55 nm, addressing applications where TM polarization is a pre-requisite. The proposed GC and the 360 nm × 800 nm strip based Si3N4 waveguides have been fabricated by optical projection lithography using an i-line stepper tool enabling low-cost and mass manufacturing of photonic-integrated-circuits.

Synthesis, pharmacological evaluation and molecular docking studies of pyrimidinedione based DPP-4 inhibitors as antidiabetic agents

Science.gov (United States)

Jha, Vibhu; Bhadoriya, Kamlendra Singh

2018-04-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of newly developed antidiabetic drugs that bock DPP-4. DPP-4 is responsible for degradation of incretins harmones such as GLP-1 (Glucagon like Peptide) and GIP (Gastric inhibitory polypeptide) that maintain blood-glucose level. Pyrimidinedione based compounds were designed and synthesized for DPP-4 inhibitory activity. These heterocycles were designed by taking Alogliptin as a reference DPP-4 inhibitors and synthesized as N-methylated and N-benzylated pyrimidinediones. These compounds were subjected to DPP-4 assay, five out of nine synthesized compounds have shown in vitro DPP-4 inhibitory activity in significant range. Further, molecular docking studies of these compounds were performed on DPP-4 subunit and compared with natural DPP-4 inhibitors like Flavone, Resveratrol, Quercetin, Diprotin A. Docking studies have led to the conclusion that there are some identical amino acid interactions as Tyr 666 and Tyr 662, seen in both synthesized compounds and natural DPP-4 inhibitors. This study completely gives a good scope for further derivatisation and optimization of synthesized compounds to get clinical candidate as DPP-4 inhibitor for antidiabetic activity.

Formulants of glyphosate-based herbicides have more deleterious impact than glyphosate on TM4 Sertoli cells.

Science.gov (United States)

Vanlaeys, Alison; Dubuisson, Florine; Seralini, Gilles-Eric; Travert, Carine

2018-05-15

Roundup and Glyphogan are glyphosate-based herbicides containing the same concentration of glyphosate and confidential formulants. Formulants are declared as inert diluents but some are more toxic than glyphosate, such as the family of polyethoxylated alkylamines (POEA). We tested glyphosate alone, glyphosate-based herbicide formulations and POEA on the immature mouse Sertoli cell line (TM4), at concentrations ranging from environmental to agricultural-use levels. Our results show that formulations of glyphosate-based herbicides induce TM4 mitochondrial dysfunction (like glyphosate, but to a lesser extent), disruption of cell detoxification systems, lipid droplet accumulation and mortality at sub-agricultural doses. Formulants, especially those present in Glyphogan, are more deleterious than glyphosate and thus should be considered as active principles of these pesticides. Lipid droplet accumulation after acute exposure to POEA suggests the rapid penetration and accumulation of formulants, leading to mortality after 24 h. As Sertoli cells are essential for testicular development and normal onset of spermatogenesis, disturbance of their function by glyphosate-based herbicides could contribute to disruption of reproductive function demonstrated in mammals exposed to these pesticides at a prepubertal stage of development. Copyright © 2017. Published by Elsevier Ltd.

A high performance hybrid battery based on aluminum anode and LiFePO4 cathode.

Science.gov (United States)

Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; Fang, Youxing; Bridges, Craig A; Paranthaman, M Parans; Dai, Sheng; Brown, Gilbert M

2016-01-28

A novel hybrid battery utilizing an aluminum anode, a LiFePO4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl3) (EMImCl-AlCl3, 1-1.1 in molar ratio) with or without LiAlCl4 is proposed. The hybrid ion battery delivers an initial high capacity of 160 mA h g(-1) at a current rate of C/5. It also shows good rate capability and cycling performance.

Development of an Aquaporin-4 Orthogonal Array of Particle-Based ELISA for Neuromyelitis Optica Autoantibodies Detection.

Directory of Open Access Journals (Sweden)

Francesco Pisani

Full Text Available Serological markers of Nuromyelitis Optica (NMO, an autoimmune disorder of the central nervous system, are autoantibodies targeting the astrocytic water channel aquaporin-4 (AQP4. We have previously demonstrated that the main epitopes for these autoantibodies (AQP4-IgG are generated by the supramolecular arrangement of AQP4 tetramers into an Orthogonal Array of Particles (OAPs. Many tests have been developed to detect AQP4-IgG in patient sera but several procedural issues affect OAP assembly and consequently test sensitivity. To date, the protein based ELISA test shows the lowest sensitivity while representing a valid alternative to the more sensitive cell based assay (CBA, which, however, shows economic, technical and interpretation problems. Here we have developed a high perfomance ELISA in which native OAPs are used as the molecular target. To this aim a native size exclusion chromatography method has been developed to isolate integral, highly pure and AQP4-IgG-recognized OAPs from rat brain. These OAPs were immobilized and oriented on a plastic plate by a sandwich approach and 139 human sera were tested, including 67 sera from NMO patients. The OAP-ELISA showed a 99% specificity and a higher sensitivity (91% compared to the CBA test. A comparative analysis revealed an end-point titer three orders of magnitude higher than the commercial ELISA and six times higher than our in-house CBA test. We show that CNS-extracted OAPs are crucial elements in order to perform an efficient AQP4-IgG test and the OAP-ELISA developed represents a valid alternative to the CBA currently used.

Analysis of (NH4)2SO4/(NH4)H2PO4 mixtures by thermogravimetry and X-ray diffraction

International Nuclear Information System (INIS)

Perez, Jose; Perez, Eduardo; Vas, Beatriz del; Garcia, Luis; Serrano, Jose Luis

2006-01-01

(NH 4 ) 2 SO 4 and (NH 4 )H 2 PO 4 are the principal components in the powder material used in fire extinguishers. In this paper the mutual influence in their thermal decomposition is investigated by thermogravimetry. Two methods for the quantification of both salts in mixtures (NH 4 ) 2 SO 4 /(NH 4 )H 2 PO 4 are proposed. The first employs thermogravimetry and is based on the measurement of the mass fraction in the 500-550 deg. C interval, once (NH 4 ) 2 SO 4 has totally decomposed to yield gaseous products. The second uses some selected peaks in the X-ray diffractogram

Production of thermoluminescent dosemeters based on MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm; Producao de dosimetros termoluminescentes a base de MgB{sub 4}O{sub 7}: Dy e MgB{sub 4}O{sub 7}: Tm

Energy Technology Data Exchange (ETDEWEB)

Souza, Luiza Freire de; Souza, Divanizia N., E-mail: luizaf25@hotmail.com, E-mail: divanizi@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Programa de Pos-Graduacao em Fisica

2013-07-01

The thermoluminescent dosimetry (TL) is a well-established technique for the detection of ionizing radiation in hospitals, clinics, and industrial establishments where there is the need to quantify the radiation. For this practice is require the use phosphors which are sensitive to radiation. Some phosphors are already commonly used in this practice, for example, TLD-100 (LiF: Mg, Ti), CaSO{sub 4}:Tm and CaSO{sub 4}:Dy. A compound that was most recently introduced in dosimetry and has many advantageous features to detect neutrons, electrons and gamma is the magnesium tetraborate (MgB{sub 4}O{sub 7}), but the undoped material is not good for dosimetry, since signal does not show satisfactory thermoluminescence. The present work presents the analysis of the compound MgB{sub 4}O{sub 7} when doped with rare earth elements, thulium (Tm) and dysprosium (Dy). The production of MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm occurred under acidic conditions. Following the process of crystal growth, several tests were made on phosphors produced to verify the quality of materials as TL dosimeter. Initially, was made the identification of the crystalline phases found in the material, using the technique of X-ray diffractometry, and then were evaluated and compared the TL emission curves of the crystals with two different types of dopants, to this, the samples were irradiated with different radiation sources: {sup 137}Cs (0,66 MeV), {sup 60}Co (1.25 MeV) and X-rays (0.41 MeV) and based on the results was evaluated the energy dependence of phosphors. Another characteristic analyzed, was the decay of TL signal for the material (fading). The results show that the material can be an excellent TL dosimeter when doped with rare earth elements Dy and Tm. (author)

Knowledge-Based Personal Health System to empower outpatients of diabetes mellitus by means of P4 Medicine.

Science.gov (United States)

Bresó, Adrián; Sáez, Carlos; Vicente, Javier; Larrinaga, Félix; Robles, Montserrat; García-Gómez, Juan Miguel

2015-01-01

Diabetes Mellitus (DM) affects hundreds of millions of people worldwide and it imposes a large economic burden on healthcare systems. We present a web patient empowering system (PHSP4) that ensures continuous monitoring and assessment of the health state of patients with DM (type I and II). PHSP4 is a Knowledge-Based Personal Health System (PHS) which follows the trend of P4 Medicine (Personalized, Predictive, Preventive, and Participative). It provides messages to outpatients and clinicians about the achievement of objectives, follow-up, and treatments adjusted to the patient condition. Additionally, it calculates a four-component risk vector of the associated pathologies with DM: Nephropathy, Diabetic retinopathy, Diabetic foot, and Cardiovascular event. The core of the system is a Rule-Based System which Knowledge Base is composed by a set of rules implementing the recommendations of the American Diabetes Association (ADA) (American Diabetes Association: http://www.diabetes.org/ ) clinical guideline. The PHSP4 is designed to be standardized and to facilitate its interoperability by means of terminologies (SNOMED-CT [The International Health Terminology Standards Development Organization: http://www.ihtsdo.org/snomed-ct/ ] and UCUM [The Unified Code for Units of Measure: http://unitsofmeasure.org/ ]), standardized clinical documents (HL7 CDA R2 [Health Level Seven International: http://www.hl7.org/index.cfm ]) for managing Electronic Health Record (EHR). We have evaluated the functionality of the system and its users' acceptance of the system using simulated and real data, and a questionnaire based in the Technology Acceptance Model methodology (TAM). Finally results show the reliability of the system and the high acceptance of clinicians.

Research ampersand development of a helium-4 based solar neutrino detector

International Nuclear Information System (INIS)

Lanou, R.E.; Maris, H.J.; Seidel, G.M.

1989-12-01

This Progress Report covers the first six months of our May 1989 Continuation Grant. The purpose of the project is to develop and test a new detection technique for neutrinos using 4 He in the superfluid state. Based upon the expected test results it should be possible to design a practical detector leading to the ultimate goal of detecting low energy solar neutrinos. During the last six months the construction phase has moved ahead substantially. Among the areas of progress discussed in the report are: the construction of the cryostat and dilution refrigerators; the gas handling systems; computer system design; tests for radioactivity of construction materials and roton pulse simulation by computer. 5 figs

Tribological Behavior of Si3N4/Ti3SiC2 Contacts Lubricated by Lithium-Based Ionic Liquids

Directory of Open Access Journals (Sweden)

Haizhong Wang

2014-01-01

Full Text Available The tribological performance of Si3N4 ball sliding against Ti3SiC2 disc lubricated by lithium-based ionic liquids (ILs was investigated using an Optimol SRV-IV oscillating reciprocating friction and wear tester at room temperature (RT and elevated temperature (100°C. Glycerol and the conventional imidazolium-based IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonylimide (L-F106 were used as references under the same experimental conditions. The results show that the lithium-based ILs had higher thermal stabilities than glycerol and lower costs associated with IL preparation than L-F106. The tribotest results show that the lithium-based ILs were effective in reducing the friction and wear of Si3N4/Ti3SiC2 contacts. [Li(urea]TFSI even produced better tribological properties than glycerol and L-F106 both at RT and 100°C. The SEM/EDS and XPS results reveal that the excellent tribological endurance of Si3N4/Ti3SiC2 contacts lubricated by lithium-based ILs was mainly attributed to the formation of surface protective films composed of various tribochemical products.

NIR-Red Spectra-Based Disaggregation of SMAP Soil Moisture to 250 m Resolution Based on SMAPEx-4/5 in Southeastern Australia

Directory of Open Access Journals (Sweden)

Nengcheng Chen

2017-01-01

Full Text Available To meet the demand of regional hydrological and agricultural applications, a new method named near infrared-red (NIR-red spectra-based disaggregation (NRSD was proposed to perform a disaggregation of Soil Moisture Active Passive (SMAP products from 36 km to 250 m resolution. The NRSD combined proposed normalized soil moisture index (NSMI with SMAP data to obtain 250 m resolution soil moisture mapping. The experiment was conducted in southeastern Australia during SMAP Experiments (SMAPEx 4/5 and validated with the in situ SMAPEx network. Results showed that NRSD performed a decent downscaling (root-mean-square error (RMSE = 0.04 m3/m3 and 0.12 m3/m3 during SMAPEx-4 and SMAPEx-5, respectively. Based on the validation, it was found that the proposed NSMI was a new alternative indicator for denoting the heterogeneity of soil moisture at sub-kilometer scales. Attributed to the excellent performance of the NSMI, NRSD has a higher overall accuracy, finer spatial representation within SMAP pixels and wider applicable scope on usability tests for land cover, vegetation density and drought condition than the disaggregation based on physical and theoretical scale change (DISPATCH has at 250 m resolution. This revealed that the NRSD method is expected to provide soil moisture mapping at 250-resolution for large-scale hydrological and agricultural studies.

Synthesis and biological evaluation of schiff bases of 4-aminophenazone as an anti-inflammatory, analgesic and antipyretic agent

Directory of Open Access Journals (Sweden)

Shahzad Murtaza

2017-01-01

Full Text Available A series of schiff base derivatives of 4-aminophenazone (4APZ-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one with different aldehydes were synthesized. The synthetic compounds were screened for their anti-inflammatory, analgesic and antipyretic activities. The characterization of synthesized compounds was carried out by 1H NMR, 13C NMR and MS. Carrageenan-induced paw oedema (CIPO and histamine induced paw oedema (HIPO methods were used to determine the anti-inflammatory activity of commercial sample of 4APZ and its synthesized schiff bases in mice. The anti-inflammatory activity was in the order of 4APZAB > 4APZBB > 4APZCB > 4APZVn and all the test compounds exhibited considerable dose dependent inhibition of the paw oedema. The effect of the compounds on membrane stabilization was also determined which showed that compounds 4APZ (120 and 240 mg/kg doses, 4APZAB (160 mg/kg and 4APZVn (600 mg/kg produced highly significant inhibition (P  4APZBB > 4APZVn > 4APZCB. Moreover, phenobarbitone-induced sleeping time (PIST in mice was also studied but only 600 mg/kg of 4APZVn significantly increased the duration of induced sleep which also suggested its sedative property. Brewer’s yeast was used to induce fever in rabbits and analysed the compounds for their antipyretic activity. Different doses of 4APZ for different time durations (240 mg/kg-after 1 h, 120 and 240 mg/kg doses-after 2 h produced highly significant (P < 0.001 inhibition of hyperpyrexia. Other compounds showed good antipyretic activity after 2, 3 and 4 h.

Monte Carlo MCNP-4B-based absorbed dose distribution estimates for patient-specific dosimetry.

Science.gov (United States)

Yoriyaz, H; Stabin, M G; dos Santos, A

2001-04-01

This study was intended to verify the capability of the Monte Carlo MCNP-4B code to evaluate spatial dose distribution based on information gathered from CT or SPECT. A new three-dimensional (3D) dose calculation approach for internal emitter use in radioimmunotherapy (RIT) was developed using the Monte Carlo MCNP-4B code as the photon and electron transport engine. It was shown that the MCNP-4B computer code can be used with voxel-based anatomic and physiologic data to provide 3D dose distributions. This study showed that the MCNP-4B code can be used to develop a treatment planning system that will provide such information in a time manner, if dose reporting is suitably optimized. If each organ is divided into small regions where the average energy deposition is calculated with a typical volume of 0.4 cm(3), regional dose distributions can be provided with reasonable central processing unit times (on the order of 12-24 h on a 200-MHz personal computer or modest workstation). Further efforts to provide semiautomated region identification (segmentation) and improvement of marrow dose calculations are needed to supply a complete system for RIT. It is envisioned that all such efforts will continue to develop and that internal dose calculations may soon be brought to a similar level of accuracy, detail, and robustness as is commonly expected in external dose treatment planning. For this study we developed a code with a user-friendly interface that works on several nuclear medicine imaging platforms and provides timely patient-specific dose information to the physician and medical physicist. Future therapy with internal emitters should use a 3D dose calculation approach, which represents a significant advance over dose information provided by the standard geometric phantoms used for more than 20 y (which permit reporting of only average organ doses for certain standardized individuals)

A new three-dimensional cobalt phosphate: Co5(OH2)4(HPO4)2(PO4)2

International Nuclear Information System (INIS)

Han Zhangang; Tian Aixiang; Peng Jun; Zhai Xueliang

2006-01-01

A three-dimensional (3D) cobalt phosphate: Co 5 (OH 2 ) 4 (HPO 4 ) 2 (PO 4 ) 2 (1), has been synthesized by hydrothermal reaction and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic techniques. The title compound is a template free cobalt phosphate. Compound 1 exhibits a complex net architecture based on edge- and corner-sharing of CoO 6 and PO 4 polyhedra. The magnetic susceptibility measurements indicated that the title compound obeys Curie-Weiss behavior down to a temperature of 17 K at which an antiferromagnetic phase transition occurs. - Graphical abstract: A 3D cobalt phosphate with a neutral framework: Co 5 (OH 2 ) 4 (HPO 4 ) 2 (PO 4 ) 2 (1), has been synthesized and characterized. Compound 1 exhibits a complex net architecture based on edge- and corner-sharing of CoO 6 and PO 4 polyhedra. Its magnetic property was researched

Buffer capacity of 4% succinylated gelatin does not provide any advantages over acidic 6% hydroxyethyl starch 130/0.4 for acid-base balance during experimental mixed acidaemia in a porcine model.

Science.gov (United States)

Esche, V; Russ, M; Melzer, S; Grossmann, B; Boemke, W; Unger, J K

2008-11-01

Four percent gelatine is an alkaline compound due to NH2 groups, whereas 6% hydroxyethyl starch 130/0.4 (HES130) has acidic features. We investigated whether these solutions lead to differences in acid-base balance in pigs during acidaemia and correction of pH. Anaesthetized pigs were randomized to HES130 or gelatine infusion (n = 5 per group). Animals received acid infusion (0.4 M solution of lactic acid and HCl diluted in normal saline) and low tidal volume ventilation (6-7 mL kg(-1), PaCO2 of 80-85 mmHg, pH 7.19-7.24). Measurements were made before and after induction of acidaemia, before and after correction of pH with haemofiltration (continuous venovenous haemofiltration) and tris-hydroxymethylaminomethane infusion. We measured parameters describing acid-base balance according to Stewart's approach, ketone body formation, oxygen delivery, haemodynamics, diuresis and urinary pH. Acid-base balance did not differ significantly between the groups. In HES130-treated pigs, the haemodilution-based drop of haemoglobin (1.4 +/- 1.0 g dL(-1), median +/- SD) was paralleled by an increase in the cardiac output (0.5 +/- 0.4 L min(-1). Lacking increases in cardiac output, gelatine-treated pigs demonstrated a reduction in oxygen delivery (149.4 +/- 106.0 mL min(-1)). Tris-hydroxymethylaminomethane volumes required for pH titration to desired values were significantly higher in the gelatine group (0.7 +/- 0.1 mL kg(-1) h(-1) vs. HES130: 0.5 +/- 0.2 mL kg(-1) h(-1)). The buffer capacity of gelatine did not lead to favourable differences in acid-base balance in comparison to HES130.

Comprehensive logic based analyses of Toll-like receptor 4 signal transduction pathway.

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Mahesh Kumar Padwal

Full Text Available Among the 13 TLRs in the vertebrate systems, only TLR4 utilizes both Myeloid differentiation factor 88 (MyD88 and Toll/Interleukin-1 receptor (TIR-domain-containing adapter interferon-β-inducing Factor (TRIF adaptors to transduce signals triggering host-protective immune responses. Earlier studies on the pathway combined various experimental data in the form of one comprehensive map of TLR signaling. But in the absence of adequate kinetic parameters quantitative mathematical models that reveal emerging systems level properties and dynamic inter-regulation among the kinases/phosphatases of the TLR4 network are not yet available. So, here we used reaction stoichiometry-based and parameter independent logical modeling formalism to build the TLR4 signaling network model that captured the feedback regulations, interdependencies between signaling kinases and phosphatases and the outcome of simulated infections. The analyses of the TLR4 signaling network revealed 360 feedback loops, 157 negative and 203 positive; of which, 334 loops had the phosphatase PP1 as an essential component. The network elements' interdependency (positive or negative dependencies in perturbation conditions such as the phosphatase knockout conditions revealed interdependencies between the dual-specific phosphatases MKP-1 and MKP-3 and the kinases in MAPK modules and the role of PP2A in the auto-regulation of Calmodulin kinase-II. Our simulations under the specific kinase or phosphatase gene-deficiency or inhibition conditions corroborated with several previously reported experimental data. The simulations to mimic Yersinia pestis and E. coli infections identified the key perturbation in the network and potential drug targets. Thus, our analyses of TLR4 signaling highlights the role of phosphatases as key regulatory factors in determining the global interdependencies among the network elements; uncovers novel signaling connections; identifies potential drug targets for

Synthesis, crystal structures, fluorescence and xanthine oxidase inhibitory activity of pyrazole-based 1,3,4-oxadiazole derivatives

Science.gov (United States)

Qi, De-Qiang; Yu, Chuan-Ming; You, Jin-Zong; Yang, Guang-Hui; Wang, Xue-Jie; Zhang, Yi-Ping

2015-11-01

A series of pyrazole-based 1,3,4-oxadiazole derivatives were rationally designed and synthesized in good yields by following a convenient route. All the newly synthesized molecules were fully characterized by IR, 1H NMR and elemental analysis. Eight compounds were structurally determined by single crystal X-ray diffraction analysis. The fluorescence properties of all the compounds were investigated in dimethyl sulfoxide media. In addition, these newly synthesized compounds were evaluated for in vitro inhibitory activity against commercial enzyme xanthine oxidase (XO) by measuring the formation of uric acid from xanthine. Among the compounds synthesized and tested, 3d and 3e were found to be moderate inhibitory activity against commercial XO with IC50 = 72.4 μM and 75.6 μM. The studies gave a new insight in further optimization of pyrazole-based 1,3,4-oxadiazole derivatives with excellent fluorescence properties and XO inhibitory activity.

Role of NH3 and NH4+ transporters in renal acid-base transport.

Science.gov (United States)

Weiner, I David; Verlander, Jill W

2011-01-01

Renal ammonia excretion is the predominant component of renal net acid excretion. The majority of ammonia excretion is produced in the kidney and then undergoes regulated transport in a number of renal epithelial segments. Recent findings have substantially altered our understanding of renal ammonia transport. In particular, the classic model of passive, diffusive NH3 movement coupled with NH4+ "trapping" is being replaced by a model in which specific proteins mediate regulated transport of NH3 and NH4+ across plasma membranes. In the proximal tubule, the apical Na+/H+ exchanger, NHE-3, is a major mechanism of preferential NH4+ secretion. In the thick ascending limb of Henle's loop, the apical Na+-K+-2Cl- cotransporter, NKCC2, is a major contributor to ammonia reabsorption and the basolateral Na+/H+ exchanger, NHE-4, appears to be important for basolateral NH4+ exit. The collecting duct is a major site for renal ammonia secretion, involving parallel H+ secretion and NH3 secretion. The Rhesus glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), are recently recognized ammonia transporters in the distal tubule and collecting duct. Rhcg is present in both the apical and basolateral plasma membrane, is expressed in parallel with renal ammonia excretion, and mediates a critical role in renal ammonia excretion and collecting duct ammonia transport. Rhbg is expressed specifically in the basolateral plasma membrane, and its role in renal acid-base homeostasis is controversial. In the inner medullary collecting duct (IMCD), basolateral Na+-K+-ATPase enables active basolateral NH4+ uptake. In addition to these proteins, several other proteins also contribute to renal NH3/NH4+ transport. The role and mechanisms of these proteins are discussed in depth in this review.

Enabling 4-Lane Based 400 G Client-Side Transmission Links with MultiCAP Modulation

DEFF Research Database (Denmark)

Tatarczak, Anna; Iglesias Olmedo, Miguel; Zuo, Tianjian

2015-01-01

We propose a uniform solution for a future client-side 400 G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300 nm wavelength band and parallel optics...

Chloride-based fast homoepitaxial growth of 4H-SiC films in a vertical hot-wall CVD

Science.gov (United States)

Guoguo, Yan; Feng, Zhang; Yingxi, Niu; Fei, Yang; Xingfang, Liu; Lei, Wang; Wanshun, Zhao; Guosheng, Sun; Yiping, Zeng

2016-06-01

Chloride-based fast homoepitaxial growth of 4H-SiC epilayers was performed on 4° off-axis 4H-SiC substrates in a home-made vertical hot-wall chemical vapor deposition (CVD) system using H2-SiH4-C2H4-HCl. The effect of the SiH4/H2 ratio and reactor pressure on the growth rate of 4H-SiC epilayers has been studied successively. The growth rate increase in proportion to the SiH4/H2 ratio and the influence mechanism of chlorine has been investigated. With the reactor pressure increasing from 40 to 100 Torr, the growth rate increased to 52 μm/hand then decreased to 47 μm/h, which is due to the joint effect of H2 and HCl etching as well as the formation of Si clusters at higher reactor pressure. The surface root mean square (RMS) roughness keeps around 1 nm with the growth rate increasing to 49 μm/h. The scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction (XRD) demonstrate that 96.7 μm thick 4H-SiC layers of good uniformity in thickness and doping with high crystal quality can be achieved. These results prove that chloride-based fast epitaxy is an advanced growth technique for 4H-SiC homoepitaxy. Project supported by the National High Technology R&D Program of China (No. 2014AA041402), the National Natural Science Foundation of China (Nos. 61474113, 61274007, 61574140), the Beijing Natural Science Foundation of China (Nos. 4132076, 4132074), the Program of State Grid Smart Grid Research Institute (No. SGRI-WD-71-14-004), and the Youth Innovation Promotion Association of CAS.

Synthesis and enzymatic evaluation of 2- and 4-aminothiazole-based inhibitors of neuronal nitric oxide synthase

Directory of Open Access Journals (Sweden)

Graham R. Lawton

2009-06-01

Full Text Available Highly potent and selective inhibitors of neuronal nitric oxide synthase (nNOS possessing a 2-aminopyridine group were recently designed and synthesized in our laboratory and were shown to have significant in vivo efficacy. In this work, analogs of our lead compound possessing 2- and 4-aminothiazole rings in place of the aminopyridine were synthesized. The less basic aminothiazole rings will be less protonated at physiological pH than the aminopyridine ring, and so the molecule will carry a lower net charge. This could lead to an increased ability to cross the blood-brain barrier thereby increasing the in vivo potency of these compounds. The 2-aminothiazole-based compound was less potent than the 2-aminopyridine-based analogue. 4-Aminothiazoles were unstable in water, undergoing tautomerization and hydrolysis to give inactive thiazolones.

Investigations of Structural Requirements for BRD4 Inhibitors through Ligand- and Structure-Based 3D QSAR Approaches

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Adeena Tahir

2018-06-01

Full Text Available The bromodomain containing protein 4 (BRD4 recognizes acetylated histone proteins and plays numerous roles in the progression of a wide range of cancers, due to which it is under intense investigation as a novel anti-cancer drug target. In the present study, we performed three-dimensional quantitative structure activity relationship (3D-QSAR molecular modeling on a series of 60 inhibitors of BRD4 protein using ligand- and structure-based alignment and different partial charges assignment methods by employing comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA approaches. The developed models were validated using various statistical methods, including non-cross validated correlation coefficient (r2, leave-one-out (LOO cross validated correlation coefficient (q2, bootstrapping, and Fisher’s randomization test. The highly reliable and predictive CoMFA (q2 = 0.569, r2 = 0.979 and CoMSIA (q2 = 0.500, r2 = 0.982 models were obtained from a structure-based 3D-QSAR approach using Merck molecular force field (MMFF94. The best models demonstrate that electrostatic and steric fields play an important role in the biological activities of these compounds. Hence, based on the contour maps information, new compounds were designed, and their binding modes were elucidated in BRD4 protein’s active site. Further, the activities and physicochemical properties of the designed molecules were also predicted using the best 3D-QSAR models. We believe that predicted models will help us to understand the structural requirements of BRD4 protein inhibitors that belong to quinolinone and quinazolinone classes for the designing of better active compounds.

Progress and Validation of Geant4 Based Radioactive Decay Simulation Using the Examples of Simbol-X and IXO

CERN Document Server

Hauf, S; Pia, M G; Bell, Z; Briel, U; Chipaux, R; Hoffmann, D H H; Kendziorra, E; Laurent, P; Strüder, L; Tenzer, C; Weidenspointer, G; Zoglauer, A

2009-01-01

The anticipated high sensitivity and the science goals of the next generation X-ray space missions, like the International X-ray Observatory or Simbol-X, rely on a low instrumental background, which in turn requires optimized shielding concepts. We present Geant4 based simulation results on the IXO Wide Field Imager cosmic ray proton induced background in comparison with previous results obtained for the Simbol-X LED and HED focal plane detectors. Our results show that an improvement in mean differential background flux compared to actually operating X-ray observatories may be feasible with detectors based on DEPFET technology. In addition we present preliminary results concerning the validation of Geant4 based radioactive decay simulation in space applications as a part of the Nano5 project.

Structure-Based Design of CSDK4-Specific Inhibitors

National Research Council Canada - National Science Library

Marmorstein, Ronen

2003-01-01

...) are implicated in more than 80% of human neoplasias (Ortega et al., 2002). For example, the gene encoding the CDK4/6 inhibitory protein, p16INK4, is deleted or mutated in the majority of leukemias, bladder cancers and familial melanomas (Roussel, 1999...

ANAM4 TBI Reaction Time-Based Tests have Prognostic Utility for Acute Concussion

Science.gov (United States)

2013-07-01

7:767. 2013 ANAM4 TBI Reaction Time-Based Tests Have Prognostic Utility for Acute Concussion LT Jacob N. Norris, MSC USN*; LCDR Waiter Carr, MSC USN...CDR Thomas Herzig, MSC USNf; CDR D. Waiter Labrie, MSC USNf; CDR Richard Sams, MC USN§ ABSTRACT The Concussion Restoration Care Center has used the...Work Unit No. N24LB. REFERENCES 1. Department of Defense: DoD Poiicy Guidance for Management of Mild Traumatic Brain Injury/Concussion in the Deployed

Inhalable delivery of AAV-based MRP4/ABCC4 silencing RNA prevents monocrotaline-induced pulmonary hypertension

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Caroline Claude

Full Text Available The ATP-binding cassette transporter MRP4 (encoded by ABCC4 regulates membrane cyclic nucleotides concentrations in arterial cells including smooth muscle cells. MRP4/ABCC4 deficient mice display a reduction in smooth muscle cells proliferation and a prevention of pulmonary hypertension in response to hypoxia. We aimed to study gene transfer of a MRP4/ABCC4 silencing RNA via intratracheal delivery of aerosolized adeno-associated virus 1 (AAV1.shMRP4 or AAV1.control in a monocrotaline-induced model of pulmonary hypertension in rats. Gene transfer was performed at the time of monocrotaline administration and the effect on the development of pulmonary vascular remodeling was assessed 35 days later. AAV1.shMRP4 dose-dependently reduced right ventricular systolic pressure and hypertrophy with a significant reduction with the higher doses (i.e., >1011 DRP/animal as compared to AAV1.control. The higher dose of AAV1.shMRP4 was also associated with a significant reduction in distal pulmonary arteries remodeling. AAV1.shMRP4 was finally associated with a reduction in the expression of ANF, a marker of cardiac hypertrophy. Collectively, these results support a therapeutic potential for downregulation of MRP4 for the treatment of pulmonary artery hypertension.

Incorporating remote sensing-based ET estimates into the Community Land Model version 4.5

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D. Wang

2017-07-01

Full Text Available Land surface models bear substantial biases in simulating surface water and energy budgets despite the continuous development and improvement of model parameterizations. To reduce model biases, Parr et al. (2015 proposed a method incorporating satellite-based evapotranspiration (ET products into land surface models. Here we apply this bias correction method to the Community Land Model version 4.5 (CLM4.5 and test its performance over the conterminous US (CONUS. We first calibrate a relationship between the observational ET from the Global Land Evaporation Amsterdam Model (GLEAM product and the model ET from CLM4.5, and assume that this relationship holds beyond the calibration period. During the validation or application period, a simulation using the default CLM4.5 (CLM is conducted first, and its output is combined with the calibrated observational-vs.-model ET relationship to derive a corrected ET; an experiment (CLMET is then conducted in which the model-generated ET is overwritten with the corrected ET. Using the observations of ET, runoff, and soil moisture content as benchmarks, we demonstrate that CLMET greatly improves the hydrological simulations over most of the CONUS, and the improvement is stronger in the eastern CONUS than the western CONUS and is strongest over the Southeast CONUS. For any specific region, the degree of the improvement depends on whether the relationship between observational and model ET remains time-invariant (a fundamental hypothesis of the Parr et al. (2015 method and whether water is the limiting factor in places where ET is underestimated. While the bias correction method improves hydrological estimates without improving the physical parameterization of land surface models, results from this study do provide guidance for physically based model development effort.

O-Succinyl-L-homoserine-based C4-chemical production: succinic acid, homoserine lactone, γ-butyrolactone, γ-butyrolactone derivatives, and 1,4-butanediol.

Science.gov (United States)

Hong, Kuk-Ki; Kim, Jeong Hyun; Yoon, Jong Hyun; Park, Hye-Min; Choi, Su Jin; Song, Gyu Hyeon; Lee, Jea Chun; Yang, Young-Lyeol; Shin, Hyun Kwan; Kim, Ju Nam; Cho, Kyung Ho; Lee, Jung Ho

2014-10-01

There has been a significant global interest to produce bulk chemicals from renewable resources using engineered microorganisms. Large research programs have been launched by academia and industry towards this goal. Particularly, C4 chemicals such as succinic acid (SA) and 1,4-butanediol have been leading the path towards the commercialization of biobased technology with the effort of replacing chemical production. Here we present O-Succinyl-L-homoserine (SH) as a new, potentially important platform biochemical and demonstrate its central role as an intermediate in the production of SA, homoserine lactone (HSL), γ-butyrolactone (GBL) and its derivatives, and 1,4-butanediol (BDO). This technology encompasses (1) the genetic manipulation of Escherichia coli to produce SH with high productivity, (2) hydrolysis into SA and homoserine (HS) or homoserine lactone hydrochloride, and (3) chemical conversion of either HS or homoserine lactone HCL (HSL·HCl) into drop-in chemicals in polymer industry. This production strategy with environmental benefits is discussed in the perspective of targeting of fermented product and a process direction compared to petroleum-based chemical conversion, which may reduce the overall manufacturing cost.

Coordination of Tridentate Schiff Base Derivatives of 4 ...

African Journals Online (AJOL)

NICO

Spectroscopic data and the X-ray crystal structures of compounds 2–4 are ... through the neutral amino nitrogen in [M(H2aap)4]Br2 (M = Co,. Ni).5 ... tion coefficients in M–1 cm–1. .... numerical absorption correction9 after optimizing the crystal.

Microstructure of the Nickel-Base Superalloy CMSX-4 Fabricated by Selective Electron Beam Melting

Science.gov (United States)

Ramsperger, Markus; Singer, Robert F.; Körner, Carolin

2016-03-01

Powder bed-based additive manufacturing (AM) processes are characterized by very high-temperature gradients and solidification rates. These conditions lead to microstructures orders of magnitude smaller than in conventional casting processes. Especially in the field of high performance alloys, like nickel-base superalloys, this opens new opportunities for homogenization and alloy development. Nevertheless, the high susceptibility to cracking of precipitation-hardenable superalloys is a challenge for AM. In this study, electron beam-based AM is used to fabricate samples from gas-atomized pre-alloyed CMSX-4 powder. The influence of the processing strategy on crack formation is investigated. The samples are characterized by optical and SEM microscopy and analyzed by microprobe analysis. Differential scanning calorimetry is used to demonstrate the effect of the fine microstructure on characteristic temperatures. In addition, in situ heat treatment effects are investigated.

Determination of prospective displacement-based gate threshold for respiratory-gated radiation delivery from retrospective phase-based gate threshold selected at 4D CT simulation

International Nuclear Information System (INIS)

Vedam, S.; Archambault, L.; Starkschall, G.; Mohan, R.; Beddar, S.

2007-01-01

Four-dimensional (4D) computed tomography (CT) imaging has found increasing importance in the localization of tumor and surrounding normal structures throughout the respiratory cycle. Based on such tumor motion information, it is possible to identify the appropriate phase interval for respiratory gated treatment planning and delivery. Such a gating phase interval is determined retrospectively based on tumor motion from internal tumor displacement. However, respiratory-gated treatment is delivered prospectively based on motion determined predominantly from an external monitor. Therefore, the simulation gate threshold determined from the retrospective phase interval selected for gating at 4D CT simulation may not correspond to the delivery gate threshold that is determined from the prospective external monitor displacement at treatment delivery. The purpose of the present work is to establish a relationship between the thresholds for respiratory gating determined at CT simulation and treatment delivery, respectively. One hundred fifty external respiratory motion traces, from 90 patients, with and without audio-visual biofeedback, are analyzed. Two respiratory phase intervals, 40%-60% and 30%-70%, are chosen for respiratory gating from the 4D CT-derived tumor motion trajectory. From residual tumor displacements within each such gating phase interval, a simulation gate threshold is defined based on (a) the average and (b) the maximum respiratory displacement within the phase interval. The duty cycle for prospective gated delivery is estimated from the proportion of external monitor displacement data points within both the selected phase interval and the simulation gate threshold. The delivery gate threshold is then determined iteratively to match the above determined duty cycle. The magnitude of the difference between such gate thresholds determined at simulation and treatment delivery is quantified in each case. Phantom motion tests yielded coincidence of simulation

Applying an animal model to quantify the uncertainties of an image-based 4D-CT algorithm

International Nuclear Information System (INIS)

Pierce, Greg; Battista, Jerry; Wang, Kevin; Lee, Ting-Yim

2012-01-01

The purpose of this paper is to use an animal model to quantify the spatial displacement uncertainties and test the fundamental assumptions of an image-based 4D-CT algorithm in vivo. Six female Landrace cross pigs were ventilated and imaged using a 64-slice CT scanner (GE Healthcare) operating in axial cine mode. The breathing amplitude pattern of the pigs was varied by periodically crimping the ventilator gas return tube during the image acquisition. The image data were used to determine the displacement uncertainties that result from matching CT images at the same respiratory phase using normalized cross correlation (NCC) as the matching criteria. Additionally, the ability to match the respiratory phase of a 4.0 cm subvolume of the thorax to a reference subvolume using only a single overlapping 2D slice from the two subvolumes was tested by varying the location of the overlapping matching image within the subvolume and examining the effect this had on the displacement relative to the reference volume. The displacement uncertainty resulting from matching two respiratory images using NCC ranged from 0.54 ± 0.10 mm per match to 0.32 ± 0.16 mm per match in the lung of the animal. The uncertainty was found to propagate in quadrature, increasing with number of NCC matches performed. In comparison, the minimum displacement achievable if two respiratory images were matched perfectly in phase ranged from 0.77 ± 0.06 to 0.93 ± 0.06 mm in the lung. The assumption that subvolumes from separate cine scan could be matched by matching a single overlapping 2D image between to subvolumes was validated. An in vivo animal model was developed to test an image-based 4D-CT algorithm. The uncertainties associated with using NCC to match the respiratory phase of two images were quantified and the assumption that a 4.0 cm 3D subvolume can by matched in respiratory phase by matching a single 2D image from the 3D subvolume was validated. The work in this paper shows the image-based 4D

Evaluation of the intensive rehabilitation protocol after arthroscopically assisted anterior cruciate ligament reconstruction

Directory of Open Access Journals (Sweden)

Dubljanin-Raspopović Emilija

2006-01-01

Full Text Available Introduction: Optimal treatment of ACL (anterior cruciate injury injuries is one of the most dynamic topics of contemporary orthopedics. Despite huge amount of publications on this subject, golden rehabilitation standard has not been established yet. Objective: The aim of our study was to compare two different rehabilitation groups in respect to dynamics and safety of recovery, and accordingly to recommend contemporary rehabilitation approach. Method: A prospective study included 45 patients with unilateral ACL rupture who were randomized into conservative (THC and intensive rehabilitation (TH-I group. The arthroscopic reconstruction of ACL was performed using the BTBP or STG graft. After the operation, in the TH-C group, ROM was limited to 0-0-90˚ and weight bearing was not allowed in the first 4 postoperative weeks. In the TH-I group, progression depended only on the knee edema and pain. The groups were compared in relation to demographic, anamnestic, and clinical characteristics (knee circumference, thigh circumference, stability tests, Lysholm, Tegner and one-leg hop test, and single stance test. Data were recorded preoperatively and postoperatively after 6 weeks, 4, 6, 9 and 12 months, and compared with parametric and non-parametric statistical tests. Results: The investigated groups clearly differed already after 6 weeks by range of motion (p<0.05, thigh circumference (p<0.01 and Lysholm test score (p<0.01, after 4 months in relation to one leg hop test (p<0.05, and after 6 months according to Tegner test (p<0.01. In the TH-I group, graft integrity was not compromised in any of these patients, nor did postoperative arthrofibrosis develop. Conclusion: Our investigation has undoubtedly revealed that early intensive rehabilitation approach leads to faster functional recovery without complications compared to conventional rehabilitation treatment.

Performance Comparison of 112-Gb/s DMT, Nyquist PAM4, and Partial-Response PAM4 for Future 5G Ethernet-Based Fronthaul Architecture

Science.gov (United States)

Eiselt, Nicklas; Muench, Daniel; Dochhan, Annika; Griesser, Helmut; Eiselt, Michael; Olmos, Juan Jose Vegas; Monroy, Idelfonso Tafur; Elbers, Joerg-Peter

2018-05-01

For a future 5G Ethernet-based fronthaul architecture, 100G trunk lines of a transmission distance up to 10 km standard single mode fiber (SSMF) in combination with cheap grey optics to daisy chain cell site network interfaces are a promising cost- and power-efficient solution. For such a scenario, different intensity modulation and direct detect (IMDD) Formats at a data rate of 112 Gb/s, namely Nyquist four-level pulse amplitude modulation (PAM4), discrete multi-tone Transmission (DMT) and partial-response (PR) PAM4 are experimentally investigated, using a low-cost electro-absorption modulated laser (EML), a 25G driver and current state-of-the-art high Speed 84 GS/s CMOS digital-to-analog converter (DAC) and analog-to-digital converter (ADC) test chips. Each modulation Format is optimized independently for the desired scenario and their digital signal processing (DSP) requirements are investigated. The performance of Nyquist PAM4 and PR PAM4 depend very much on the efficiency of pre- and post-equalization. We show the necessity for at least 11 FFE-taps for pre-emphasis and up to 41 FFE coefficients at the receiver side. In addition, PR PAM4 requires an MLSE with four states to decode the signal back to a PAM4 signal. On the contrary, bit- and power-loading (BL, PL) is crucial for DMT and an FFT length of at least 512 is necessary. With optimized parameters, all Modulation formats result in a very similar performances, demonstrating a transmission distance of up to 10 km over SSMF with bit error rates (BERs) below a FEC threshold of 4.4E-3, allowing error free transmission.

Synthesis of cyclophosphamide-4,4,5,5-d4

International Nuclear Information System (INIS)

Walsh, S.P.; Chang, Y.H.; Ludeman, S.M.

1995-01-01

3-Hydroxypropionitrile was subjected to a base-catalyzed exchange reaction in D 2 O which provided 2,2-dideuterio-3-deuteroxypropionitrile (DOCH 2 CD 2 CN) in 70% yield. Reduction of the nitrile with LiAID 4 gave 3-amino-2,2,3,3-tetradeuteriopropan-1-ol (HOCH 2 CD 2 CD 2 NH 2 ) in a crude yield of 71%. Reaction of this intermediate with N,N-bis(2-chloroethyl)phosphoramidic dichloride [Cl 2 P(O)N(CH 2 CH 2 Cl) 2 ] followed by the combination of those chromatography fractions which contained only pure material gave cyclophosphamide-4,4,5,5-d 4 as a white oil in 13% yield. A portion of this oil was converted to the monohydrate by the addition of water (1.1 equivalents) and crystallization from ether/petroleum ether (62% yield). For the hydrate, MS analyses gave an average mole percent enrichment (with average deviation over 5 determinations) of 89.1 ± 0.5% d 4 . (author)

Thermal effects of an ICL-based mid-infrared CH4 sensor within a wide atmospheric temperature range

Science.gov (United States)

Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; Girija, Aswathy V.; He, Qixin; Zheng, Huadan; Griffin, Robert J.; Tittel, Frank K.

2018-03-01

The thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ∼25 °C was measured for 5 h and its Allan deviation was ∼2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to minimize these effects. An environmental test chamber was employed to investigate the thermal effects that occur in the sensor system with variation of the test chamber temperature between 10 and 30 °C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH4 standard gas sample. Indoor/outdoor CH4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.

A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

Science.gov (United States)

Deylami, Mohammad N; Jovanov, Emil

2014-01-01

The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

Optical sensor platform based on cellulose nanocrystals (CNC) - 4'-(hexyloxy)-4-biphenylcarbonitrile (HOBC) bi-phase nematic liquid crystal composite films.

Science.gov (United States)

Santos, Moliria V; Tercjak, Agnieszka; Gutierrez, Junkal; Barud, Hernane S; Napoli, Mariana; Nalin, Marcelo; Ribeiro, Sidney J L

2017-07-15

The preparation of composite materials has gained tremendous attention due to the potential synergy of the combined materials. Here we fabricate novel thermal/electrical responsive photonic composite films combining cellulose nanocrystals (CNC) with a low molecular weight nematic liquid crystal (NLC), 4'-(hexyloxy)-4-biphenylcarbonitrile (HOBC). The obtained composite material combines both intense structural coloration of photonic cellulose and thermal and conductive properties of NLC. Scanning electron microscopy (SEM) results confirmed that liquid crystals coated CNC films maintain chiral nematic structure characteristic of CNC film and simultaneously, transversal cross-section scanning electron microscopy images indicated penetration of liquid crystals through the CNC layers. Investigated composite film maintain NLC optical properties being switchable as a function of temperature during heating/cooling cycles. The relationship between the morphology and thermoresponsive in the micro/nanostructured materials was investigated by using transmission optical microscopy (TOM). Conductive response of the composite films was proved by Electrostatic force microscopy (EFM) measurement. Designed thermo- and electro-responsive materials open novel simple pathway of fabrication of CNC-based materials with tunable properties. Copyright © 2017. Published by Elsevier Ltd.

Quad 14Gbps L-Band VCSEL-based System for WDM Migration of 4-lanes 56 Gbps Optical Data Links

DEFF Research Database (Denmark)

Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang

2012-01-01

We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty.......We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty....

Effect of Barrier Metal Based on Titanium or Molybdenum in Characteristics of 4H-SiC Schottky Diodes

Directory of Open Access Journals (Sweden)

M. Ben Karoui

2014-05-01

Full Text Available The electrical properties were extracted by I-V and C-V analysis, performed from 10 K to 450 K. When the annealing temperature varied to 400 °C, the Schottky barrier height (SBH increased from 0.85 Ev to 1.20 eV in Ti/4H-SiC whereas in the Mo/4H-SiC the SBH varied from 1.04 eV to 1.10 eV. Deformation of J-V-T characteristics was observed in two types of devices when the temperature decreases from 300 K to 10 K. The electrical properties and the stability of the devices have been correlated to the fabrication processes and to the metal/semiconductor interfaces. Mo-based contacts show better behaviour in forward polarization when compared to the Ti-based Schottky contacts, with ideality factors close to the unity even after the annealing process. However, Mo-based contacts show leakage currents higher than that measured on the more optimized Ti-based Schottky.

Comparison of cell-based assays for the identification and evaluation of competitive CXCR4 inhibitors.

Directory of Open Access Journals (Sweden)

Anneleen Van Hout

Full Text Available The chemokine receptor CXCR4 is activated by its unique chemokine ligand CXCL12 and regulates many physiological and developmental processes such as hematopoietic cell trafficking. CXCR4 is also one of the main co-receptors for human immunodeficiency virus (HIV entry. Dysfunction of the CXCL12/CXCR4 axis contributes to several human pathologies, including cancer and inflammatory diseases. Consequently, inhibition of CXCR4 activation is recognized as an attractive target for therapeutic intervention. In this regard, numerous agents modifying CXCR4 activity have been evaluated in in vitro experimental studies and pre-clinical models. Here, we evaluated a CXCL12 competition binding assay for its potential as a valuable initial screen for functional and competitive CXCR4 inhibitors. In total, 11 structurally diverse compounds were included in a side-by-side comparison of in vitro CXCR4 cell-based assays, such as CXCL12 competition binding, CXCL12-induced calcium signaling, CXCR4 internalization, CXCL12-guided cell migration and CXCR4-specific HIV-1 replication experiments. Our data indicated that agents that inhibit CXCL12 binding, i.e. the anti-CXCR4 peptide analogs T22, T140 and TC14012 and the small molecule antagonists AMD3100, AMD3465, AMD11070 and IT1t showed inhibitory activity with consistent relative potencies in all further applied CXCR4-related assays. Accordingly, agents exerting no or very weak receptor binding (i.e., CTCE-9908, WZ811, Me6TREN and gambogic acid showed no or very poor anti-CXCR4 inhibitory activity. Thus, CXCL12 competition binding studies were proven to be highly valuable as an initial screening assay and indicative for the pharmacological and functional profile of competitive CXCR4 antagonists, which will help the design of new potent CXCR4 inhibitors.

Na2SO4-based solid electrolytes for SOx sensors

DEFF Research Database (Denmark)

Rao, N.; Schoonman, J.; Toft Sørensen, O.

1992-01-01

on the phases present and the structure of the specimens. From a point of view of practical application as SOx sensor material, the Na2SO4 + 5 mol% Y2(SO4)3 + Na2WO4 and Na2SO4+ 4 mol% La2(SO4)3 + Na2WO4 materials are better than undoped Na2SO4 because of their higher conductivity, and absence of a phase...

Lanthanide - actinide separation: a challenge in the back end of nuclear fuel cycle

International Nuclear Information System (INIS)

Mohapatra, P.K.

2015-01-01

Due to their similar size and chemical state, separation of trivalent lanthanide and actinide ions has always been a challenging topic of research. Of late, the growing concern for the radioactive waste management in the back end of the nuclear fuel cycle has led to the possibility of transmuting the long-lived transuranides in high flux reactors. This necessitates the development of processes for the separation of lanthanides and actinides in acidic/low pH media. In view of the high absorption cross section of few lanthanides, their presence in relatively large proportion (10-100 times) impedes the transmutation process. Processes such as the TRAMEX and TALSPEAK have been used for the separation of lanthanides from trivalent actinides. Of late soft donor ligands containing S and N donor atoms have been used for the selective extraction of trivalent actinide ions. The commercially available S-donor compound, CYANEX 301 (bis(2,4,4-trimethylpentyl) dithiophosphinic acid) has been used to yield separation factor (S.F.) values in the excess of 6000. Synergistic extraction with N-donor ligands such as 2,2'-bipyridyl and 1,10-phenanthroline have yielded S.F. values close to 40,000. N-donor ligands such as BTP (bis-triazinylpyridine), BTBP (bis-triazinylbipyridyl) and BTPhen (bis-triazinyl-phenanthroline) have been particularly effective from relatively acidic feed conditions. The present lecture will give a brief outline of the separation processes and experimental results of studies carried out using various S and N donor ligands. Use of room temperature ionic liquids for more favorable separations will be highlighted. Liquid membrane separation results for application to back end nuclear fuel cycle will also be discussed. (author)

TH-E-17A-02: High-Pitch and Sparse-View Helical 4D CT Via Iterative Image Reconstruction Method Based On Tensor Framelet

International Nuclear Information System (INIS)

Guo, M; Nam, H; Li, R; Xing, L; Gao, H

2014-01-01

Purpose: 4D CT is routinely performed during radiation therapy treatment planning of thoracic and abdominal cancers. Compared with the cine mode, the helical mode is advantageous in temporal resolution. However, a low pitch (∼0.1) for 4D CT imaging is often required instead of the standard pitch (∼1) for static imaging, since standard image reconstruction based on analytic method requires the low-pitch scanning in order to satisfy the data sufficient condition when reconstructing each temporal frame individually. In comparison, the flexible iterative method enables the reconstruction of all temporal frames simultaneously, so that the image similarity among frames can be utilized to possibly perform high-pitch and sparse-view helical 4D CT imaging. The purpose of this work is to investigate such an exciting possibility for faster imaging with lower dose. Methods: A key for highpitch and sparse-view helical 4D CT imaging is the simultaneous reconstruction of all temporal frames using the prior that temporal frames are continuous along the temporal direction. In this work, such a prior is regularized through the sparsity transform based on spatiotemporal tensor framelet (TF) as a multilevel and high-order extension of total variation transform. Moreover, GPU-based fast parallel computing of X-ray transform and its adjoint together with split Bregman method is utilized for solving the 4D image reconstruction problem efficiently and accurately. Results: The simulation studies based on 4D NCAT phantoms were performed with various pitches (i.e., 0.1, 0.2, 0.5, and 1) and sparse views (i.e., 400 views per rotation instead of standard >2000 views per rotation), using 3D iterative individual reconstruction method based on 3D TF and 4D iterative simultaneous reconstruction method based on 4D TF respectively. Conclusion: The proposed TF-based simultaneous 4D image reconstruction method enables high-pitch and sparse-view helical 4D CT with lower dose and faster speed

4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C₇₀ based organic solar cells

DEFF Research Database (Denmark)

Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

2017-01-01

Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

Schiff Bases of Benzothiazol-2-ylamine and Thiazolo[5,4-b] pyridin-2-ylamine as Anticonvulsants: Synthesis, Characterization and Toxicity Profiling.

Science.gov (United States)

Shukla, Rashmi; Singh, Ajeet P; Sonar, Pankaj K; Mishra, Mudita; Saraf, Shailendra K

2016-01-01

Schiff bases have a broad spectrum of biological activities like antiinflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic and so forth. Thus, after a thorough perusal of literature, it was decided to conjugate benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine with aromatic and heteroaromatic aldehydes to get a series of Schiff bases. Synthesis, characterization, in-silico toxicity profiling and anticonvulsant activity of the Schiff bases of Benzothiazol-2-ylamine and Thiazolo [5, 4-b] pyridin-2-ylamine. Aniline/4-aminopyridine was converted to the corresponding thiourea derivatives, which were cyclized to obtain benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine. Finally, these were condensed with various aromatic and heteroaromatic aldehydes to obtain Schiff bases of benzothiazol-2-ylamine and thiazolo [5, 4-b] pyridin-2-ylamine. The synthesized compounds were characterized and screened for their anticonvulsant activity using maximal electroshock (MES) test and isoniazid (INH) induced convulsions test. In-silico toxicity profiling of all the synthesized compounds was done through "Lazar" and "Osiris" properties explorer. Majority of the compounds were more potent against MES induced convulsions than INH induced convulsions. Schiff bases of benzothiazol-2-ylamine were more effective than thiazolo [5, 4-b] pyridin-2-ylamine against MES induced convulsions. The compound benzothiazol-2-yl-(1H-indol-2-ylmethylene)-amine (VI) was the most potent member of the series against both types of convulsions. Compound VI exhibited the most significant activity profile in both the models. The compounds did not exhibit any carcinogenicity or acute toxicity in the in-silico studies. Thus, it may be concluded that the Schiff bases of benzothiazol-2-ylamine exhibit the potential to be promising and non-toxic anticonvulsant agents.

Characterization of Schiff bases derived from 3,4-dimethoxybenzaldehyde: the crystal structure of n,n′-bis(3,4-dimethoxybenzylidene)-2,2-dimethylpropane-1,3-diamine hydrate

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Foroghnia, A.; Fejfarová, Karla; Dušek, Michal

2013-01-01

Roč. 54, č. 4 (2013), s. 774-778 ISSN 0022-4766 Institutional research plan: CEZ:AV0Z10100521 Keywords : diimine * Schiff base * spectroscopy * single crystal X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.501, year: 2013

New 1,3,4-Oxadiazole Based Photosensitizers for Dye Sensitized Solar Cells (DSSCs

Directory of Open Access Journals (Sweden)

Umer Mehmood

2015-01-01

Full Text Available 1,3,4-Oxadiazole based photosensitizers with biphenyl, naphthalene, anthracene, and triphenylamine as the electron-donating moiety were synthesized for solar cell applications. In these photosensitizers, cyano groups were introduced as the electron acceptor and the anchor group because of their high electron-withdrawing ability and strong bonding to the semiconductor. Oxadiazole isomers were used as the π-conjugation system, which bridges the donor-acceptor systems. The electrochemical and optical properties of the sensitizers were investigated both in their native form and upon incorporation into dye sensitized solar cells. The results of UV-visible absorption spectroscopy, electrochemical impedance spectroscopic measurements, and photocurrent voltage characteristics indicate that 1,3,4-oxadiazole pi-spacer with the anthracene moiety has the highest efficiency of 2.58%. Density functional theory was employed to optimize the structures of the sensitizers and the TiO2 cluster.

4P-NPD ultra-thin films as efficient exciton blocking layers in DBP/C70 based organic solar cells

Science.gov (United States)

Patil, Bhushan R.; Liu, Yiming; Qamar, Talha; Rubahn, Horst-Günter; Madsen, Morten

2017-09-01

Exciton blocking effects from ultra-thin layers of N,N‧-di-1-naphthalenyl-N,N‧-diphenyl [1,1‧:4‧,1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD) were investigated in small molecule-based inverted organic solar cells (OSCs) using tetraphenyldibenzoperiflanthene as the electron donor material and fullerene (C70) as the electron acceptor material. The short-circuit current density (J SC) and power conversion efficiency (PCE) of the optimized OSCs with 0.7 nm thick 4P-NPD were approximately 16% and 24% higher, respectively, compared to reference devices without exciton blocking layers (EBLs). Drift diffusion-based device modeling was conducted to model the full current density-voltage (JV) characteristics and external quantum efficiency spectrum of the OSCs, and photoluminescence measurements were conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies of the device behaviors and exciton generation rates and densities in the active layer for different 4P-NPD layer thicknesses were conducted, in order to gain a complete understanding of the observed increase in PCE for 4P-NPD layer thicknesses up to 1 nm, and the observed decrease in PCE for layer thicknesses beyond 1 nm. This work demonstrates a route for guiding the integration of EBLs in OSC devices.

Neutral coordination polymers based on a metal-mono(dithiolene) complex: synthesis, crystal structure and supramolecular chemistry of [Zn(dmit)(4,4'-bpy)]n, [Zn(dmit)(4,4'-bpe)]n and [Zn(dmit)(bix)]n (4,4'-bpy = 4,4'-bipyridine, 4,4'-bpe = trans-1,2-bis(4-pyridyl)ethene, bix = 1,4-bis(imidazole-1-ylmethyl)-benzene.

Science.gov (United States)

Madhu, Vedichi; Das, Samar K

2011-12-28

This article describes a unique synthetic route that enables a neutral mono(dithiolene)metal unit, {Zn(dmit)}, to link with three different organic molecules, resulting in the isolation of a new class of neutral coordination polymers. The species {Zn(dmit)} coordinates with 4,4'-bipyridine (4,4'-bpy), trans-1,2-bis(4-pyridyl)ethene (4,4'-bpe) and 1,4-bis(imidazole-1-ylmethyl)-benzene (bix) as linkers giving rise to the formation of coordination polymers [Zn(dmit)(4,4'-bpy)](n) (1), [Zn(dmit)(4,4'-bpe)](n) (2) and [Zn(dmit)(bix)](n) (3) respectively. Compounds 1-3 were characterized by elemental analyses, IR, diffuse reflectance and single crystal X-ray diffraction studies. Compounds 1 and 3 crystallize in the monoclinic space group P2(1)/n, whereby compound 2 crystallizes in triclinic space group P1[combining macron]. In the present study, we chose three linkers 4,4'-bpy, 4,4'-bpe and bix (see , respectively, for their structural drawings), that differ in terms of their molecular dimensions. The crystal structures of compounds 1-3 are described here in terms of their supramolecular diversities that include π-π interactions, not only among aromatic stacking (compounds 1 and 3), but also between an aromatic ring and an ethylenic double bond (compound 2). The electronic absorption spectroscopy of compounds 1-3 support these intermolecular π-π interactions. This journal is © The Royal Society of Chemistry 2011

A web- and mobile phone-based intervention to prevent obesity in 4-year-olds (MINISTOP): a population-based randomized controlled trial.

Science.gov (United States)

Delisle, Christine; Sandin, Sven; Forsum, Elisabet; Henriksson, Hanna; Trolle-Lagerros, Ylva; Larsson, Christel; Maddison, Ralph; Ortega, Francisco B; Ruiz, Jonatan R; Silfvernagel, Kristin; Timpka, Toomas; Löf, Marie

2015-02-07

Childhood obesity is an increasing health problem globally. Overweight and obesity may be established as early as 2-5 years of age, highlighting the need for evidence-based effective prevention and treatment programs early in life. In adults, mobile phone based interventions for weight management (mHealth) have demonstrated positive effects on body mass, however, their use in child populations has yet to be examined. The aim of this paper is to report the study design and methodology of the MINSTOP (Mobile-based Intervention Intended to Stop Obesity in Preschoolers) trial. A two-arm, parallel design randomized controlled trial in 300 healthy Swedish 4-year-olds is conducted. After baseline measures, parents are allocated to either an intervention- or control group. The 6- month mHealth intervention consists of a web-based application (the MINSTOP app) to help parents promote healthy eating and physical activity in children. MINISTOP is based on the Social Cognitive Theory and involves the delivery of a comprehensive, personalized program of information and text messages based on existing guidelines for a healthy diet and active lifestyle in pre-school children. Parents also register physical activity and intakes of candy, soft drinks, vegetables as well as fruits of their child and receive feedback through the application. Primary outcomes include body fatness and energy intake, while secondary outcomes are time spent in sedentary, moderate, and vigorous physical activity, physical fitness and intakes of fruits and vegetables, snacks, soft drinks and candy. Food and energy intake (Tool for Energy balance in Children, TECH), body fatness (pediatric option for BodPod), physical activity (Actigraph wGT3x-BT) and physical fitness (the PREFIT battery of five fitness tests) are measured at baseline, after the intervention (six months after baseline) and at follow-up (12 months after baseline). This novel study will evaluate the effectiveness of a mHealth program for

Stair Climbing Control for 4-DOF Tracked Vehicle Based on Internal Sensors

Directory of Open Access Journals (Sweden)

Daisuke Endo

2017-01-01

Full Text Available In search-and-rescue missions, multi-degrees-of-freedom (DOF tracked robots that are equipped with subtracks are commonly used. These types of robots have superior locomotion performance on rough terrain. However, in teleoperated missions, the performance of tracked robots depends largely on the operators’ ability to control every subtrack appropriately. Therefore, an autonomous traversal function can significantly help in the teleoperation of such robots. In this paper, we propose a planning and control method for 4-DOF tracked robots climbing up/down known stairs automatically based on internal sensors. Experimental results obtained using mockup stairs verify the effectiveness of the proposed method.

On functional bases of the first-order differential invariants for non-conjugate subgroups of the Poincaré group $P(1,4$

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V.M. Fedorchuk

2008-11-01

Full Text Available It is established which functional bases of the first-order differential invariants of the splitting and non-splitting subgroups of the Poincaré group $P(1,4$ are invariant under the subgroups of the extended Galilei group $widetilde G(1,3 subset P(1,4$. The obtained sets of functional bases are classified according to dimensions.

Analytics4Action Evaluation Framework: A Review of Evidence-Based Learning Analytics Interventions at the Open University UK

Science.gov (United States)

Rienties, Bart; Boroowa, Avinash; Cross, Simon; Kubiak, Chris; Mayles, Kevin; Murphy, Sam

2016-01-01

There is an urgent need to develop an evidence-based framework for learning analytics whereby stakeholders can manage, evaluate, and make decisions about which types of interventions work well and under which conditions. In this article, we will work towards developing a foundation of an Analytics4Action Evaluation Framework (A4AEF) that is…

A fast universal immobilization of immunoglobulin G at 4 °C for the development of array-based immunoassays.

Directory of Open Access Journals (Sweden)

Shu-Lin Guo

Full Text Available To maintain the antibody activity and enhance performance of array-based immunoassays, protein G was used to allow a shorter duration of immunoglobulin G immobilization at 4 °C, with the antibody placed in the appropriate orientation. The multiplexed detection of six pain-related message molecules (PRMMs was used as examples for the development of array-based immunoassays: substance P, calcitonin gene-related peptide, nerve growth factor, brain-derived neurotrophic factor, tumor necrosis factor-α, and β-endorphin. Protein G- and non-protein G-coated slides were tested. Compared to non-protein G immunoassays, protein G shortened the antibody immobilization time at 4 °C from overnight to 2 hours. Only protein G-facilitated immunoassays succeeded in simultaneously detecting all six PRMMs with high specificity. Dose-response curves showed that the limits of detection of the protein G-multiplexed immunoassays for the PRMMs was approximately 164, 167, 120, 60, 80, and 92 pg/ml, respectively. Thus, protein G effectively shortens the duration of antibody immobilization at 4 °C, allowing the use of sensitive array-based immunoassays for the simultaneous detection of PRMMs.

Acid/Base and H2PO4(-) Controllable High-Contrast Optical Molecular Switches with a Novel BODIPY Functionalized [2]Rotaxane.

Science.gov (United States)

Arumugaperumal, Reguram; Srinivasadesikan, Venkatesan; Ramakrishnam Raju, Mandapati V; Lin, Ming-Chang; Shukla, Tarun; Singh, Ravinder; Lin, Hong-Cheu

2015-12-09

A novel multifunctional mechanically interlocked switchable [2]rotaxane R4 containing two molecular stations and rotaxane arms terminated with boron-dipyrromethene (BODIPY) fluorophores and its derivatives were synthesized for the first time by CuAAC click reaction. The shuttling motion of macrocycle between the dibenzylammonium and triazolium recognition sites and the distance dependent photoinduced electron transfer process of R4 is demonstrated by utilizing external chemical stimuli (acid/base). Interestingly, the reversible self-assembly process of R4 was recognized by the acid-base molecular switch strategy. Notably, two symmetrical triazolium groups acted as molecular stations, H2PO4(-) receptors, and H-bonded donors. Both [2]rotaxane R4 and thread R2 demonstrated excellent optical responses and high selectivity toward H2PO4(-) ion. The specific motion and guest-host interactions of mechanically interlocked machines (MIMs) were also further explored by quantum mechanical calculations. The thread R2 also demonstrated to enable the detection of H2PO4(-) in RAW 264.7 cells successfully.

Production and characterization of compounds based on MgB4O7 for application in dosimetry

International Nuclear Information System (INIS)

Souza, Luiza Freire de

2016-01-01

Many materials with luminescent properties are used for ionizing radiation dosimetry through the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. Detectors based on lithium fluoride (LiF), calcium sulphate (CaSO 4 ) and aluminum oxide (Al 2 O 3 ), doped or codoped with various elements, are the TL or OSL commercial dosimeters most widely used currently. However, several researches are focused to the development of new TL /OSL materials in intention to enhance the dosimetric properties, in view that no TL/OSL dosimeter has all the ideal characteristics for monitoring the radiation. In this context, magnesium tetraborate (MgB 4 O 7 ), which has been presented in the literature as a material for dosimetry TL, was investigated in this work. As there are no reports on the structural characterization of this material or regarding to its applicability on OSL dosimetry, the proposal of the present work was to develop compounds based on MgB 4 O 7 , with different doping, by solid state synthesis. It was made the structural, optical, TL and OSL characterization of the compound to verify it feasibility for application on radiation dosimetry. Initially, it was determined the calcination temperature and time for MgB 4 O 7 formation, with the use of thermal analyses and x ray diffraction. The ideal calcination was found at 900 °C for 7 hours. It were produced , in powder form, the compounds: MgB 4 O 7 , MgB 4 O 7 :Dy, MgB 4 O 7 :Dy,Li, MgB 4 O 7 :Ce, MgB 4 O 7 :Ce,Li, MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li. For TL and OSL analyses it were produced pellets sintering at 950 °C for 2 hours. The radioluminescence (RL) analyses of MgB 4 O 7 :Dy and MgB 4 O 7 :Dy,Li shows wavelength emissions at 490, 590, 670 and 760 nm. For MgB 4 O 7 :Ce and MgB 4 O 7 :Ce,Li RL was observed wide emission band in the ultraviolet region. For the MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li RL were not observed emission from the ultraviolet to infrared. With the results obtained from

Enhancement of reactivity in Li4SiO4-based sorbents from the nano-sized rice husk ash for high-temperature CO2 capture

International Nuclear Information System (INIS)

Wang, Ke; Zhao, Pengfei; Guo, Xin; Li, Yimin; Han, Dongtai; Chao, Yang

2014-01-01

Highlights: • The Li 4 SiO 4 sorbent from nano-sized rice husk ash was prepared and characterized. • The Aerosil and Quartz were comparably used for synthesized Li 4 SiO 4 . • The structure of sorbent was depended on the morphology of heated silicon materials. • The pretreatment sorbent showed increase in the CO 2 uptake and kinetic behavior. • This promising sorbent also maintained higher capacities during the multiple cycles. - Abstract: Using the cost-effective, renewable and nano-sized of citric acid pretreatment rice husk ash (CRHA) as silicon source, high efficient Li 4 SiO 4 (lithium orthosilicate)-based sorbents (CRHA-Li 4 SiO 4 ) for high-temperature CO 2 capture were prepared through the solid-state reaction at lower temperature (700 °C). Two typical raw materials (nano-structured Aerosil and crystalline Quartz powders) were used to synthesize Li 4 SiO 4 sorbents (Aerosil-Li 4 SiO 4 and Quartz-Li 4 SiO 4 ) for comparison purposes. The phase composition behavior, surface area, and morphology of the silicon sources, heat treated raw materials and as-received Li 4 SiO 4 sorbents were studied by analytical techniques. The CO 2 adsorption capacity and adsorption–desorption performance were tested by the thermo-gravimetric analyses (CO 2 atmosphere) and a fixed bed reactor, respectively. Compared with the case of its original samples, the morphology of heat treated raw materials had a greater effect on the phase composition, microstructure, special surface area and CO 2 adsorption properties of their resulting sorbents. Although the calcined Quartz sample maintained the structure of micron particles, its reactivity was not enough to react completely with Li 2 CO 3 . Due to the greater reactivity of nanoparticles, Aerosil-Li 4 SiO 4 presented pure of Li 4 SiO 4 whereas it obtained large particles with dense morphology, which was coming from the pronounced fusing of silica nanoparticles during the calcined process. Conversely, CRHA-Li 4 SiO 4

Advanced reprocessing developments in Europe contribution of European projects ACSEPT and ACTINET-I3

Energy Technology Data Exchange (ETDEWEB)

Bourg, S.; Poinssot, C. [CEA DEN, Nuclear Energy Div., RadioChemistry and Processes Dept., F-30207Bagnols sur Ceze (France); Geist, A. [KIT-INE (Germany); Cassayre, L. [CIEMAT (Spain); Rhodes, C. [NNL-UK (United Kingdom); Ekberg, C. [CHALMERS (Sweden)

2012-07-01

Nuclear energy has more than ever to demonstrate that it can contribute safely and on a sustainable way to answer the international increase in energy needs. Actually, in addition to an increased safety of the reactors themselves, its acceptance is still closely associated to our capability to reduce the lifetime of the nuclear waste, to manage them safely and to propose options for a better use of the natural resources. Spent fuel reprocessing can help to reach these objectives. But this cannot be achieved only by optimizing industrial processes through engineering studies. It is of a primary importance to increase our fundamental knowledge in actinide sciences in order to build the future of nuclear energy on reliable and scientifically-founded results, and therefore meet the needs of the future fuel cycles in terms of fabrication and performance of fuels, reprocessing and waste management. At the European level, both the collaborative project ACSEPT and the Integrated Infrastructure Initiative ACTINET-I3 work together to improve our knowledge in actinides chemistry and therefore develop advanced separation processes. These tools are complementary and work in close connection on some specific issues such as the understanding of the selectivity of extracting organic ligands. By offering trans-national access to the main nuclear research facility in Europe, ACTINET-I3 aims at increasing the knowledge in actinide sciences by gathering all the expertise available in European nuclear research institutes or university and giving them the opportunity to come and work in hot-labs (ITU, Atalante...) or beamlines (ESFR, ANKA, PSI) ACSEPT is focused on the development of advanced separation processes, both aqueous and pyrochemical. Head-end steps, fuel re-fabrication, solvent treatment, waste management are also taken into account. In aqueous process development, the SANEX and innovative SANEX flowsheets demonstration were successfully achieved. Chemical systems were

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions

Energy Technology Data Exchange (ETDEWEB)

Tunsu, Cristian, E-mail: tunsu@chalmers.se; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-02-15

Highlights: • A wet-based decontamination process for fluorescent lamp waste is proposed. • Mercury can be leached using iodine in potassium iodide solution. • The efficiency of the process increases with an increase in leachant concentration. • Selective leaching of mercury from rare earth elements is achieved. • Mercury is furthered recovered using ion exchange, reduction or solvent extraction. - Abstract: With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent’s concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I{sub 2}/KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5 M I{sub 2}/KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe{sub 4}BTBP showed good removal of mercury

A novel dual-salts of LiTFSI and LiODFB in LiFePO4-based batteries for suppressing aluminum corrosion and improving cycling stability

Science.gov (United States)

Li, Faqiang; Gong, Yan; Jia, Guofeng; Wang, Qinglei; Peng, Zhengjun; Fan, Wei; Bai, Bing

2015-11-01

The strong corrosion behavior at the Al current collector restricts the application range of lithium bis (trifluoromethanesulfonylimide) (LiTFSI), despite its high stability against water and thermal. SEM, LSV and Tafel curves proved that adding LiODFB into LiTFSI-based electrolytes could suppress aluminum corrosion caused by LiTFSI-based electrolytes. The cycling stability and rate capability of LiFePO4-based batteries using LiTFSI0.6-LiODFB0.4-based electrolytes is excellent as compared to LiFePO4-based batteries using LiPF6-based electrolytes.

Keypoint-based 4-Points Congruent Sets - Automated marker-less registration of laser scans

Science.gov (United States)

Theiler, Pascal Willy; Wegner, Jan Dirk; Schindler, Konrad

2014-10-01

We propose a method to automatically register two point clouds acquired with a terrestrial laser scanner without placing any markers in the scene. What makes this task challenging are the strongly varying point densities caused by the line-of-sight measurement principle, and the huge amount of data. The first property leads to low point densities in potential overlap areas with scans taken from different viewpoints while the latter calls for highly efficient methods in terms of runtime and memory requirements. A crucial yet largely unsolved step is the initial coarse alignment of two scans without any simplifying assumptions, that is, point clouds are given in arbitrary local coordinates and no knowledge about their relative orientation is available. Once coarse alignment has been solved, scans can easily be fine-registered with standard methods like least-squares surface or Iterative Closest Point matching. In order to drastically thin out the original point clouds while retaining characteristic features, we resort to extracting 3D keypoints. Such clouds of keypoints, which can be viewed as a sparse but nevertheless discriminative representation of the original scans, are then used as input to a very efficient matching method originally developed in computer graphics, called 4-Points Congruent Sets (4PCS) algorithm. We adapt the 4PCS matching approach to better suit the characteristics of laser scans. The resulting Keypoint-based 4-Points Congruent Sets (K-4PCS) method is extensively evaluated on challenging indoor and outdoor scans. Beyond the evaluation on real terrestrial laser scans, we also perform experiments with simulated indoor scenes, paying particular attention to the sensitivity of the approach with respect to highly symmetric scenes.

Influence of Polyethylene Glycol (PEG in CMC-NH4BR Based Polymer Electrolytes: Conductivity and Electrical Study

Directory of Open Access Journals (Sweden)

Nur Khalidah Zainuddin

2017-04-01

Full Text Available The present work was carried with new type and promising polymer electrolytes system by development of carboxylmethylcellulose (CMC doped NH4Br and plasticized with polyethylene glycol (PEG. The sample was successfullyprepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity andthermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedancespectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable forthe conductance and assist to enhancing the ionic conductivity of the CMC-NH4Br-PEG electrolyte system. The addition of PEG to the CMC-based electrolyte can enhance towards the cation mobility which is turn increases ionic conductivity. The conductivity-temperature of plasticized BdPEs system was found obeys the Arrhenius relation where the ionic conductivity increases with temperature and activation energy for the ions hopping of the highest conducting PEs system only required small value to migrate. The electrical studies show a non-Debye behaviour of BdPEs based on the analyzed data using complex permittivity, ε* and complex electrical modulus, M* of the sample at different temperature.

Metal-organic framework based on copper(I) sulfate and 4,4'-bipyridine catalyzes the cyclopropanation of styrene

International Nuclear Information System (INIS)

Shi Fanian; Silva, Ana Rosa; Rocha, Joao

2011-01-01

The hydrothermal synthesis of a new metal-organic framework (MOF) formulated as Cu 2 (4,4'-bpy) 2 SO 4 .6(H 2 O), [abbreviation: (1); bpy or 4,4'-bpy=4,4'-bipyridine; SO 4 2- =sulfate group] has been reported. The structure of this MOF consists of Cu + nodes connected via 4,4'-bpy to form infinite chains, with two neighboring chains further bridged on the nodes by SO 4 2- , resulting in a 1-D double chain network. Guest water molecules reside in between the chains and are hydrogen-bonded to the O and S atoms from the nearest sulfate groups, leading to the formation of a 3-D supramolecular framework. This MOF is good heterogeneous catalyst for the cyclopropanation of styrene, with high trans cyclopropane diastereoselectivity and was recycled and reused for three consecutive cycles without a significant loss of catalytic activity. - Graphical Abstract: A new MOF structure built up of 4,4 ' -bipyridine, sulphate and Cu(I), is an active heterogeneous catalyst for cyclopropanation of styrene with ethyldiazoacetate. Highlights: → The synthesis is different from solvothermal synthesis for other Cu(I) compounds. → The compound and the structure are new. → H bonds form infinite planes among water molecules and sulphate species. → H bonding interaction makes the structure into a 3D supramolecular framework. → Active catalytic property as heterogeneous catalyst for cyclopropanation of styrene.

Time skewing and amplitude nonlinearity mitigation by feedback equalization for 56 Gbps VCSEL-based PAM-4 links

Science.gov (United States)

You, Yue; Zhang, Wenjia; Sun, Lin; Du, Jiangbing; Liang, Chenyu; Yang, Fan; He, Zuyuan

2018-03-01

The vertical cavity surface emitting laser (VCSEL)-based multimode optical transceivers enabled by pulse amplitude modulation (PAM)-4 will be commercialized in near future to meet the 400-Gbps standard short reach optical interconnects. It is still challenging to achieve over 56/112-Gbps with the multilevel signaling as the multimode property of the device and link would introduce the nonlinear temporal response for the different levels. In this work, we scrutinize the distortions that relates to the multilevel feature of PAM-4 modulation, and propose an effective feedback equalization scheme for 56-Gbps VCSEL-based PAM-4 optical interconnects system to mitigate the distortions caused by eye timing-skew and nonlinear power-dependent noise. Level redistribution at Tx side is theoretically modeled and constructed to achieve equivalent symbol error ratios (SERs) of four levels and improved BER performance. The cause of the eye skewing and the mitigation approach are also simulated at 100-Gbps and experimentally investigated at 56-Gbps. The results indicate more than 2-dB power penalty improvement has been achieved by using such a distortion aware equalizer.

A Ru(II) complex with 2-(4-(methylsulfonyl)phenyl)-1H-imidazo[4,5- f][1,10]phenanthroline: Synthesis, characterization, and acid-base and DNA-binding properties

Science.gov (United States)

Gao, Jie; Wang, Zhi-Ping; Yuan, Cui-Li; Jia, Hai-Shun; Wang, Ke-Zhi

2011-09-01

A new Ru(II) complex of [Ru(bpy) 2(Hmspip)]Cl 2 {in which bpy = 2,2'-bipyridine, Hmspip = 2-(4-(methylsulfonyl)phenyl)-1 H-imidazo[4,5- f][1,10]phenanthroline} have been synthesized and characterized. The ground- and excited-state acid-base properties of [Ru(bpy) 2(Hmspip)]Cl 2 and its parent complex of [Ru(bpy) 2(Hpip)]Cl 2 {Hpip = 2-phenyl-1H-imidazo[4,5- f][1,10]phenanthroline} have been studied by UV-visible (UV-vis) and emission spectrophotometric pH titrations. [Ru(bpy) 2(Hmspip)]Cl 2 acts as a calf thymus DNA intercalators with a binding constant of 4.0 × 10 5 M -1 in buffered 50 mM NaCl, as evidenced by UV-vis and luminescence titrations, steady-state emission quenching by [Fe(CN) 6] 4-, DNA competitive binding with ethidium bromide, reverse salt titrations and viscosity measurements.

Aqueous based asymmetrical-bipolar electrochemical capacitor with a 2.4 V operating voltage

Science.gov (United States)

Wu, Haoran; Lian, Keryn

2018-02-01

A novel asymmetrical-bipolar electrochemical capacitor system leveraging the contributions of a Zn-CNT asymmetrical electrode and a KOH-H2SO4 dual-pH electrolyte was developed. The positive and negative electrodes operated in electrolytes with different pH, exploiting the maximum potential of both electrodes, which led to a cell voltage of 2.4 V. The potential tracking of both electrodes revealed that the Zn negative electrode could maintain a potential at -1.2 V, while the CNT positive electrode can be charged to +1.2 V without significant irreversible reactions. A bipolar ion exchange membrane has effectively separated the acid and alkaline from neutralization, which resulted in stable performance of the device with capacitance retention of 94% and coulombic efficiency of 99% over 10,000 cycles. This asymmetrical-bipolar design overcomes the thermodynamic limit of water decomposition, opening a new avenue towards high energy and high power density aqueous-based ECs.

Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

International Nuclear Information System (INIS)

Gurzynski, Lukasz; Puszko, Aniela; Ostrzechowska, Agnieszka; Makowski, Mariusz; Chmurzynski, Lech

2006-01-01

(Acid+base) equilibrium constants, involving the acidity (pK a AC ) and cationic homoconjugation constants (in the form of lgK BHB + AC ), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK a AN andlgK BHB + AN ) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity

Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

Energy Technology Data Exchange (ETDEWEB)

Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Ostrzechowska, Agnieszka [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

2006-05-15

(Acid+base) equilibrium constants, involving the acidity (pK{sub a}{sup AC}) and cationic homoconjugation constants (in the form of lgK{sub BHB{sup +}}{sup AC}), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK{sub a}{sup AN}andlgK{sub BHB{sup +}}{sup AN}) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity.

2,4,6-Trichlorophenylhydrazine Schiff bases as DPPH radical and super oxide anion scavengers.

Science.gov (United States)

Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Ali, Sajjad; Ambreen, Nida; Perveen, Shahnaz; Choudhary, M Iqbal; Voelter, Wolfgang

2012-05-01

Syntheses of thirty 2,4,6-trichlorophenylhydrazine Schiff bases 1-30 were carried out and evaluated for their in vitro DPPH radical and super oxide anion scavenging activities. Compounds 1-30 have shown a varying degree of DPPH radical scavenging activity and their IC50 values range between 4.05-369.30 µM. The compounds 17, 28, 18, 14, 8, 15, 12, 2, 29, and 7 exhibited IC50 values ranging between 4.05±0.06-24.42±0.86 µM which are superior to standard n-propylgallate (IC50=30.12±0.27 µM). Selected compounds have shown a varying degree of superoxide anion radical scavenger activity and their IC50 values range between 91.23-406.90 µM. The compounds 28, 8, 17, 15, and 14, showed IC50 values between 91.23±1.2-105.31±2.29 µM which are superior to standard n-propylgallate (IC50=106.34±1.6 µM).

Poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite based thin films for Schottky diode application

Energy Technology Data Exchange (ETDEWEB)

Gupta, Bhavana, E-mail: bgupta1206@gmail.com [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre of Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Mehta, Minisha, E-mail: mehta.mini@gmail.com [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre of Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Melvin, Ambrose [Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha, Pune 411008 (India); Kamalakannan, R.; Dash, S.; Kamruddin, M.; Tyagi, A.K. [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre of Atomic Research, Kalpakkam, Tamil Nadu 603102 (India)

2014-10-15

Transparent, conductive films of poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite were synthesized by in-situ oxidative polymerization and investigated for their Schottky diode property. The prepared films were characterized by UV–Vis spectroscopy, thermal gravimetric analysis (TGA), surface resistivity, cyclic voltametery, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). SEM reveals the formation of homogeneous and adhesive polymer films while HRTEM confirms the uniform wrapping of polymer chains around the nanotube walls for PEDOT-FWCNT film. Improved thermal stability, conductivity and charge storage property of PEDOT in the presence of FWCNT is observed. Among different compositions, 5 wt. % of FWCNT is found to be optimum with sheet resistance and transmittance of 500 Ω sq{sup −1} and 77%, respectively. Moreover, the electronic and junction properties of polymer films were studied and compared by fabricating sandwich type devices with a configuration of Al/PEDOT or PEDOT-FWCNT nanocomposite/indium tin oxide (ITO) coated glass. The measured current density-voltage characteristics show typical rectifying behavior for both configurations. However, enhanced rectification ratio and higher forward current density is observed in case of PEDOT-FWCNT based Schottky diode. Furthermore, reliability test depicts smaller hysteresis effect and better performance of PEDOT-FWCNT based diodes. - Highlights: • Single step synthesis of PEDOT and PEDOT-FWCNT nanocomposites films via in-situ oxidative polymerization. • Thermal, electrical and electrochemical properties of films show positive effect of FWCNT on PEDOT films. • Schottky diodes based on metal Al/PEDOT or PEDOT-FWCNT composites/ITO glass are fabricated. • Improved electrical characteristics with better reliability is achieved for PEDOT-FWCNT based diodes.

Poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite based thin films for Schottky diode application

International Nuclear Information System (INIS)

Gupta, Bhavana; Mehta, Minisha; Melvin, Ambrose; Kamalakannan, R.; Dash, S.; Kamruddin, M.; Tyagi, A.K.

2014-01-01

Transparent, conductive films of poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite were synthesized by in-situ oxidative polymerization and investigated for their Schottky diode property. The prepared films were characterized by UV–Vis spectroscopy, thermal gravimetric analysis (TGA), surface resistivity, cyclic voltametery, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). SEM reveals the formation of homogeneous and adhesive polymer films while HRTEM confirms the uniform wrapping of polymer chains around the nanotube walls for PEDOT-FWCNT film. Improved thermal stability, conductivity and charge storage property of PEDOT in the presence of FWCNT is observed. Among different compositions, 5 wt. % of FWCNT is found to be optimum with sheet resistance and transmittance of 500 Ω sq −1 and 77%, respectively. Moreover, the electronic and junction properties of polymer films were studied and compared by fabricating sandwich type devices with a configuration of Al/PEDOT or PEDOT-FWCNT nanocomposite/indium tin oxide (ITO) coated glass. The measured current density-voltage characteristics show typical rectifying behavior for both configurations. However, enhanced rectification ratio and higher forward current density is observed in case of PEDOT-FWCNT based Schottky diode. Furthermore, reliability test depicts smaller hysteresis effect and better performance of PEDOT-FWCNT based diodes. - Highlights: • Single step synthesis of PEDOT and PEDOT-FWCNT nanocomposites films via in-situ oxidative polymerization. • Thermal, electrical and electrochemical properties of films show positive effect of FWCNT on PEDOT films. • Schottky diodes based on metal Al/PEDOT or PEDOT-FWCNT composites/ITO glass are fabricated. • Improved electrical characteristics with better reliability is achieved for PEDOT-FWCNT based diodes

Direct-write fabrication of 4D active shape-changing behavior based on a shape memory polymer and its nanocomposite (Conference Presentation)

Science.gov (United States)

Wei, Hongqiu; Zhang, Qiwei; Yao, Yongtao; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2017-04-01

Shape memory polymers (SMPs), a typical class of smart materials, have been witnessed significant advances in the past decades. Based on the unique performance to recover the initial shape after going through a shape deformation, the applications of SMPs have aroused growing interests. However, most of the researches are hindered by traditional processing technologies which limit the design space of SMPs-based structures. Three-dimension (3D) printing as an emerging technology endows design freedom to manufacture materials with complex structures. In present article, we show that by employing direct-write printing method; one can realize the printing of SMPs to achieve 4D active shape-changing structures. We first fabricated a kind of 3D printable polylactide (PLA)-based SMPs and characterized the overall properties of such materials. Results demonstrated the prepared PLA-based SMPs presenting excellent shape memory effect. In what follows, the rheological properties of such PLA-based SMP ink during printing process were discussed in detail. Finally, we designed and printed several 3D configurations for investigation. By combining 3D printing with shape memory behavior, these printed structures achieve 4D active shape-changing performance under heat stimuli. This research presents a high flexible method to realize the fabrication of SMP-based 4D active shape-changing structures, which opens the way for further developments and improvements of high-tech fields like 4D printing, soft robotics, micro-systems and biomedical devices.

Weather resistance of CaSO4 ṡ 1/2H2O-based sand-fixation material

Science.gov (United States)

Liu, Xin; Tie, Shengnian

2017-07-01

Searching for an economical and effective sand-fixing material and technology is of great importance in Northwest China. This paper described the use of a semihydrated gypsum-(CaSO4 ṡ 1/2H2O-)based composite as a sand-fixing material. Its morphology and composition were characterized by SEM, and its water resistance, freezing-thawing resistance and wind erosion resistance were tested in the field. The results indicated that semihydrated gypsum-(CaSO4 ṡ 1/2H2O-)based sand-fixing composite has good water resistance and water-holding capacity. Its strength is maintained at 1.42 MPa after 50 freezing and thawing cycles, and its wind erosion increases with increasing wind speed and slope. Its compressive strength starts to decrease after nine months of field tests with no change in appearance, but it still satisfies the requirements of fixation technology. This sand-fixing material should have wide application owing to its good weather resistance.

Study of Allocation Guaranteed Time Slot Wireless Body Area Networks Based on IEEE 802.15.4

Science.gov (United States)

Yundra, E.; Harsono, G. D.

2018-04-01

This paper aims to determine the size of the Guaranteed Time Slot (GTS) on the super frame structure required for each sensor as well as to know the performance of the GTS resized system compared to the GTS standard on IEEE 802.15.4. This article proposes a scheme to improve IEEE 802.15.4 medium access control, called allocation Guaranteed Time Slot (ALGATIS). ALGATIS is expected to effectively allocate guaranteed time slot to the requested sensors, it adjusts the length of the slot in super frame duration based on the length of the packet data. This article presents a simulation experiment of IEEE 802.15.4, especially for star network, to predict the throughput of networks and average energy consumption. The simulation experiments show that the performance of ALGATIS is better than that of IEEE 802.15.4 standard in term of the throughput of networks and average energy consumption

Multifunctional Analysis of CD4+ T-Cell Response as Immune-Based Model for Tuberculosis Detection

Directory of Open Access Journals (Sweden)

Miriam Lichtner

2015-01-01

Full Text Available Mono- and multifunctional specific CD4+ and CD8+ T-cell responses were evaluated to improve the immune-based detection of active tuberculosis (TB and latent infection (LTBI. We applied flow cytometry to investigate cytokines profile (IFN-γ, TNF-α, and IL-2 of T cells after stimulation with TB antigens in 28 TB-infected subjects (18 active TB and 10 LTBI and 10 uninfected controls. Cytokines production by CD4+ T cells at single-cell levels was higher in TB-infected subjects than uninfected controls P0.45%, it was possible to differentiate TB-infected (>0.45% by uninfected subjects (0.182%. The magnitude of CD8+ T-cell responses showed no differences between active TB and LTBI. Multifunctional CD4+ T-cell responses could have the potential to identify at single time point subjects without TB infection and patients having active or latent TB.

Nanoscale Relationship Between CD4 and CD25 of T Cells Visualized with NSOM/QD-Based Dual-Color Imaging System

Science.gov (United States)

Fan, Jinping; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

2015-10-01

In this study, by using of near-field scanning optical microscopy (NSOM)/immune-labeling quantum dot (QD)-based dual-color imaging system, we achieved the direct visualization of nanoscale profiles for distribution and organization of CD4 and CD25 molecules in T cells. A novel and interesting finding was that though CD25 clustering as nanodomains were observed on the surface of CD4+CD25high regulatory T cells, these CD25 nanodomains were not co-localized with CD4 nanodomains. This result presented that the formation of these CD25 nanodomains on the surface of CD4+CD25high T cells were not associated with the response of T cell receptor (TCR)/CD3-dependent signal transduction. In contrast, on the surface of CD4+CD25low T cells, CD25 molecules distributed randomly without forming nanodomains while CD4 clustering as nanodomains can be observed; on the surface of CD8+CD25+ T cells, CD25 clustering as nanodomains and co-localization with CD8 nanodomains were observed. Collectively, above these results exhibited that TCR/CD3-based microdomains were indeed required for TCR/CD3-mediated T cells activation and enhanced the immune activity of CD4+CD25low T cells or CD8+CD25+ T cells. In particular, it was found that the formation of CD25 nanodomains and their segregation from TCR/CD3 microdomains were the intrinsic capability of CD4+CD25high T cells, suggesting this specific imaging feature of CD25 should be greatly associated with the regulatory activity of CD4+CD25high T cells. Importantly, this novel NSOM/QD-based dual-color imaging system will provide a useful tool for the research of distribution-function relationship of cell-surface molecules.

Improving the electrochemical properties of nanosized LiFePO4-based electrode by boron doping

International Nuclear Information System (INIS)

Trócoli, Rafael; Franger, Sylvain; Cruz, Manuel; Morales, Julián; Santos-Peña, Jesús

2014-01-01

Highlights: • Thermal treatment of boron phosphate with LiFePO 4 provides electrode materials with high performance in lithium half-cells: 160 mAh·g -1 (90% of theoretical capacity) under C/5 rate • The products are composites containing boron-modified LiFePO 4 , FePO 4 and an amorphous phase with ionic diffusion properties • The boron treatment affects textural, conductive and lithium diffusivity of the electrode material leading to higher performance • A limited boron-doping of the phospholivine structure is observed - Abstract: Electrode materials with homogeneous distribution of boron were obtained by heating mixtures of nanosized carbon-coated lithium iron phosphate and BPO 4 in 3-9% weight at 700 °C. The materials can be described as nanocomposites containing i) LiFePO 4 , possibly doped with a low amount of boron, ii) FePO 4 and iii) an amorphous layer based on Li 4 P 2 O 7 -derived material that surrounds the phosphate particles. The thermal treatment with BPO 4 also triggered changes in the carbon coating graphitic order. Galvanostatic and voltammetric studies in lithium half-cells showed smaller polarisation, higher capacity and better cycle life for the boron-doped composites. For instance, one of the solids, called B 6 -LiFePO 4 , provided close to 150 and 140 mAhg -1 (87% and 81% of theoretical capacity, respectively) under C/2.5 and C regimes after several cycles. Improved specific surface area, carbon graphitization, conductivity and lithium ion diffusivity in the boron-doped phospholivine network account for this excellent rate performance. The properties of an amorphous layer surrounding the phosphate particles also account for such higher performance

Comparison Of Keyword Based Clustering Of Web Documents By Using Openstack 4j And By Traditional Method

Directory of Open Access Journals (Sweden)

Shiza Anand

2015-08-01

Full Text Available As the number of hypertext documents are increasing continuously day by day on world wide web. Therefore clustering methods will be required to bind documents into the clusters repositories according to the similarity lying between the documents. Various clustering methods exist such as Hierarchical Based K-means Fuzzy Logic Based Centroid Based etc. These keyword based clustering methods takes much more amount of time for creating containers and putting documents in their respective containers. These traditional methods use File Handling techniques of different programming languages for creating repositories and transferring web documents into these containers. In contrast openstack4j SDK is a new technique for creating containers and shifting web documents into these containers according to the similarity in much more less amount of time as compared to the traditional methods. Another benefit of this technique is that this SDK understands and reads all types of files such as jpg html pdf doc etc. This paper compares the time required for clustering of documents by using openstack4j and by traditional methods and suggests various search engines to adopt this technique for clustering so that they give result to the user querries in less amount of time.

WE-AB-202-09: Feasibility and Quantitative Analysis of 4DCT-Based High Precision Lung Elastography

International Nuclear Information System (INIS)

Hasse, K; Neylon, J; Low, D; Santhanam, A

2016-01-01

Purpose: The purpose of this project is to derive high precision elastography measurements from 4DCT lung scans to facilitate the implementation of elastography in a radiotherapy context. Methods: 4DCT scans of the lungs were acquired, and breathing stages were subsequently registered to each other using an optical flow DIR algorithm. The displacement of each voxel gleaned from the registration was taken to be the ground-truth deformation. These vectors, along with the 4DCT source datasets, were used to generate a GPU-based biomechanical simulation that acted as a forward model to solve the inverse elasticity problem. The lung surface displacements were applied as boundary constraints for the model-guided lung tissue elastography, while the inner voxels were allowed to deform according to the linear elastic forces within the model. A biomechanically-based anisotropic convergence magnification technique was applied to the inner voxels in order to amplify the subtleties of the interior deformation. Solving the inverse elasticity problem was accomplished by modifying the tissue elasticity and iteratively deforming the biomechanical model. Convergence occurred when each voxel was within 0.5 mm of the ground-truth deformation and 1 kPa of the ground-truth elasticity distribution. To analyze the feasibility of the model-guided approach, we present the results for regions of low ventilation, specifically, the apex. Results: The maximum apical boundary expansion was observed to be between 2 and 6 mm. Simulating this expansion within an apical lung model, it was observed that 100% of voxels converged within 0.5 mm of ground-truth deformation, while 91.8% converged within 1 kPa of the ground-truth elasticity distribution. A mean elasticity error of 0.6 kPa illustrates the high precision of our technique. Conclusion: By utilizing 4DCT lung data coupled with a biomechanical model, high precision lung elastography can be accurately performed, even in low ventilation regions of

WE-AB-202-09: Feasibility and Quantitative Analysis of 4DCT-Based High Precision Lung Elastography

Energy Technology Data Exchange (ETDEWEB)

Hasse, K; Neylon, J; Low, D; Santhanam, A [UCLA, Los Angeles, CA (United States)

2016-06-15

Purpose: The purpose of this project is to derive high precision elastography measurements from 4DCT lung scans to facilitate the implementation of elastography in a radiotherapy context. Methods: 4DCT scans of the lungs were acquired, and breathing stages were subsequently registered to each other using an optical flow DIR algorithm. The displacement of each voxel gleaned from the registration was taken to be the ground-truth deformation. These vectors, along with the 4DCT source datasets, were used to generate a GPU-based biomechanical simulation that acted as a forward model to solve the inverse elasticity problem. The lung surface displacements were applied as boundary constraints for the model-guided lung tissue elastography, while the inner voxels were allowed to deform according to the linear elastic forces within the model. A biomechanically-based anisotropic convergence magnification technique was applied to the inner voxels in order to amplify the subtleties of the interior deformation. Solving the inverse elasticity problem was accomplished by modifying the tissue elasticity and iteratively deforming the biomechanical model. Convergence occurred when each voxel was within 0.5 mm of the ground-truth deformation and 1 kPa of the ground-truth elasticity distribution. To analyze the feasibility of the model-guided approach, we present the results for regions of low ventilation, specifically, the apex. Results: The maximum apical boundary expansion was observed to be between 2 and 6 mm. Simulating this expansion within an apical lung model, it was observed that 100% of voxels converged within 0.5 mm of ground-truth deformation, while 91.8% converged within 1 kPa of the ground-truth elasticity distribution. A mean elasticity error of 0.6 kPa illustrates the high precision of our technique. Conclusion: By utilizing 4DCT lung data coupled with a biomechanical model, high precision lung elastography can be accurately performed, even in low ventilation regions of

Straightforward hit identification approach in fragment-based discovery of bromodomain-containing protein 4 (BRD4) inhibitors.

Science.gov (United States)

Borysko, Petro; Moroz, Yurii S; Vasylchenko, Oleksandr V; Hurmach, Vasyl V; Starodubtseva, Anastasia; Stefanishena, Natalia; Nesteruk, Kateryna; Zozulya, Sergey; Kondratov, Ivan S; Grygorenko, Oleksandr O

2018-05-09

A combination approach of a fragment screening and "SAR by catalog" was used for the discovery of bromodomain-containing protein 4 (BRD4) inhibitors. Initial screening of 3695-fragment library against bromodomain 1 of BRD4 using thermal shift assay (TSA), followed by initial hit validation, resulted in 73 fragment hits, which were used to construct a follow-up library selected from available screening collection. Additionally, analogs of inactive fragments, as well as a set of randomly selected compounds were also prepared (3 × 3200 compounds in total). Screening of the resulting sets using TSA, followed by re-testing at several concentrations, counter-screen, and TR-FRET assay resulted in 18 confirmed hits. Compounds derived from the initial fragment set showed better hit rate as compared to the other two sets. Finally, building dose-response curves revealed three compounds with IC 50  = 1.9-7.4 μM. For these compounds, binding sites and conformations in the BRD4 (4UYD) have been determined by docking. Copyright © 2018 Elsevier Ltd. All rights reserved.

Production and characterization of compounds based on MgB{sub 4}O{sub 7} for application in dosimetry; Producao e caracterizacao de compostos a base de MgB{sub 4}O{sub 7} para aplicacao em dosimetria

Energy Technology Data Exchange (ETDEWEB)

Souza, Luiza Freire de

2016-07-01

Many materials with luminescent properties are used for ionizing radiation dosimetry through the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. Detectors based on lithium fluoride (LiF), calcium sulphate (CaSO{sub 4}) and aluminum oxide (Al{sub 2}O{sub 3}), doped or codoped with various elements, are the TL or OSL commercial dosimeters most widely used currently. However, several researches are focused to the development of new TL /OSL materials in intention to enhance the dosimetric properties, in view that no TL/OSL dosimeter has all the ideal characteristics for monitoring the radiation. In this context, magnesium tetraborate (MgB{sub 4}O{sub 7}), which has been presented in the literature as a material for dosimetry TL, was investigated in this work. As there are no reports on the structural characterization of this material or regarding to its applicability on OSL dosimetry, the proposal of the present work was to develop compounds based on MgB{sub 4}O{sub 7}, with different doping, by solid state synthesis. It was made the structural, optical, TL and OSL characterization of the compound to verify it feasibility for application on radiation dosimetry. Initially, it was determined the calcination temperature and time for MgB{sub 4}O{sub 7} formation, with the use of thermal analyses and x ray diffraction. The ideal calcination was found at 900 °C for 7 hours. It were produced , in powder form, the compounds: MgB{sub 4}O{sub 7}, MgB{sub 4}O{sub 7}:Dy, MgB{sub 4}O{sub 7}:Dy,Li, MgB{sub 4}O{sub 7}:Ce, MgB{sub 4}O{sub 7}:Ce,Li, MgB{sub 4}O{sub 7}:Nd and MgB{sub 4}O{sub 7}:Nd,Li. For TL and OSL analyses it were produced pellets sintering at 950 °C for 2 hours. The radioluminescence (RL) analyses of MgB{sub 4}O{sub 7}:Dy and MgB{sub 4}O{sub 7}:Dy,Li shows wavelength emissions at 490, 590, 670 and 760 nm. For MgB{sub 4}O{sub 7}:Ce and MgB{sub 4}O{sub 7}:Ce,Li RL was observed wide emission band in the ultraviolet region. For the Mg

Polylactide-based polyurethane shape memory nanocomposites (Fe3O4/PLAUs) with fast magnetic responsiveness

International Nuclear Information System (INIS)

Gu, Shu-Ying; Jin, Sheng-Peng; Gao, Xie-Feng; Mu, Jian

2016-01-01

Polylactide-based polyurethane shape memory nanocomposites (Fe 3 O 4 /PLAUs) with fast magnetic responsiveness are presented. For the purpose of fast response and homogeneous dispersion of magnetic nanoparticles, oleic acid was used to improve the dispersibility of Fe 3 O 4 nanoparticles in a polymer matrix. A homogeneous distribution of Fe 3 O 4 nanoparticles in the polymer matrix was obtained for nanocomposites with low Fe 3 O 4 loading content. A small agglomeration was observed for nanocomposites with 6 wt% and 9 wt% loading content, leading to a small decline in the mechanical properties. PLAU and its nanocomposites have glass transition around 52 °C, which can be used as the triggering temperature. PLAU and its nanocomposites have shape fixity ratios above 99%, shape recovery ratios above 82% for the first cycle and shape recovery ratios above 91% for the second cycle. PLAU and its nanocomposites also exhibit a fast water bath or magnetic responsiveness. The magnetic recovery time decreases with an increase in the loading content of Fe 3 O 4 nanoparticles due to an improvement in heating performance for increased weight percentage of fillers. The nanocomposites have fast responses in an alternating magnetic field and have potential application in biomedical areas such as intravascular stent. (paper)

A new ion selective electrode for cesium (I) based on calix[4]arene-crown-6 compounds.

Science.gov (United States)

Ramanjaneyulu, P S; Kumar, Abha Naveen; Sayi, Y S; Ramakumar, K L; Nayak, S K; Chattopadhyay, S

2012-02-29

A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium has been developed. 25,27-Dihydroxycalix[4]arene-crown-6 (L1), 5,11,17,23-tetra-tert-butyl-25,27-dimethoxycalix[4]arene-crown-6 (L2) and 25,27-bis(1-octyloxy)calix[4]arene-crown-6 (L3) were investigated for their use as ionophores. The cation exchange resin DOWEX-50W was used to maintain low activity Cs+ in inner filling solution to improve the performance. The best response for cesium was observed with L3 along with optimized membrane constituents and composition. Excellent Nernstian response (56.6 mV/decade of Cs(I)) over the concentration range 10(-7) to 10(-2)M of Cs(I) was obtained with a fast response time of less than 10s. Detection limit for Cs(I) using the present ISE is 8.48×10(-8) M Cs(I). Separate solution method (SSM) was applied to ascertain the selectivity for Cs(I) over alkali, alkaline earth and transition metal ions. The response of ISE for Cs(I) was fairly constant over the pH range of 4-11. The lifetime of the electrode is 10 months which is the highest life for any membrane based Cs-ISE so far developed. The concentration of cesium ion in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing AAS. Copyright © 2011 Elsevier B.V. All rights reserved.

Adjustment of serum HE4 to reduced glomerular filtration and its use in biomarker-based prediction of deep myometrial invasion in endometrial cancer

DEFF Research Database (Denmark)

Chovanec, Josef; Selingerova, Iveta; Greplova, Kristina

2017-01-01

based on single-institution data from 120 EC patients and validated against multicentric data from 379 EC patients. Results: In non-cancer individuals, serum HE4 levels increase log-linearly with reduced glomerular filtration of eGFR = 90 ml/min/1.73 m2. HE4ren, adjusting HE4 serum levels to decreased e...... levels to reduced eGFR that enables quantification of time-dependent changes in HE4 production and elimination irrespective of age and renal function in women. Utilizing HE4ren improves performance of biomarker-based models for prediction of dMI in endometrial cancer patients....

Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

Science.gov (United States)

Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.

2015-04-01

This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

International Nuclear Information System (INIS)

Lee, Taek-Soo; Frey, Eric C; Tsui, Benjamin M W

2015-01-01

This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99m Tc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

Electroactive ionic liquids based on 2,5-ditert-butyl-1,4-dimethoxybenzene and triflimide anion as redox shuttle for Li4Ti5O12/LiFePO4 lithium-ion batteries

Science.gov (United States)

Gélinas, Bruno; Bibienne, Thomas; Dollé, Mickael; Rochefort, Dominic

2017-12-01

In order to increase the solubility and oxidation potential of redox shuttles, electroactive ionic liquids (RILs) based on the modification of 1,4-dimethoxybenzene with triflimide anions were synthesized. We developed two synthetic routes to obtain these RILs in which the triflimide was either linked on the benzene ring or as a ether on 2,5-ditert-butyl-1,4-dimethoxybenzene (DDB). These RILs all have melting points below 100 °C, but above room temperature. The structural impact of electroactive anion was evaluated in this study by determining the redox potential and electrochemical stability. The electrochemical properties of these RILs were investigated by cyclic voltammetry and the diffusion coefficients were measured by double potential step chronoamperometry. The viscosity and ionic conductivity measurements of redox-active electrolyte were obtained at different temperatures and the RIL additives are shown to have a low impact on these electrolyte properties at concentrations up to 0.3 M. The charge-overcharge-discharge cycles of Li/LiFePO4 half-cells and Li4Ti5O12/LiFePO4 full cells with a 100% overcharge are presented using redox-active electrolyte (0.3 M concentration level) at 0.1 C rate. This study highlights the potential of electroactive ionic liquids as highly soluble and stable functional additives in Li-ion battery electrolytes.

Linagliptin, a xanthine-based dipeptidyl peptidase-4 inhibitor with an unusual profile for the treatment of type 2 diabetes

DEFF Research Database (Denmark)

Deacon, Carolyn F; Holst, Jens Juul

2010-01-01

data presented at Scientific Meetings and peer-reviewed studies published since 2007. WHAT THE READER WILL GAIN: This article reviews pharmacokinetic and pharmacodynamic characteristics of linagliptin. Linagliptin belongs to a new chemical class of dipeptidyl pepidase-4 (DPP-4) inhibitors, which...... comprise xanthine-based compounds. It is a potent, long-acting inhibitor with high selectivity for DPP-4 versus the related enzymes DPP-8 and DPP-9. The drug has modest oral availability in humans, but is absorbed rapidly to inhibit plasma DPP-4 activity by > 80% over 24 h. It is not metabolized...

OPTIMASI KLASIFIKASI SEL TUNGGAL PAP SMEAR MENGGUNAKAN CORRELATION BASED FEATURES SELECTION (CFS BERBASIS C4.5 DAN NAIVE BAYES

Directory of Open Access Journals (Sweden)

Asti Herliana

2016-11-01

Full Text Available Abstract – Cervical cancer was the most dangerous disease and generally attacks women. Early detection through Pap Smear method was one way to prevent the desease to grow in womans cervival canal. Based on the result of Pap Smear methode, the single cell of data that known as herlev data is available. This data, then used as a reference by the experts to find the best level classification from each class of cervical cancer. The decision tree C4.5 and Naïve Bayes have proven to give the best result on 280 data trial of herlev with support by Correlation based Features Selection (CFS optimization method. The issues raised in the present study was does CFS optimization methode that combined with the classification method of C4.5 and Naïve Bayes can provide increased the accuracy results when it faced the 917 data of herlev. The results of this study show that CFS method that combined either with C4.5 methods and naïve bayes classification accuracy was decrease when compared without using CFS method. In terms of showing that CFS can not provide the best result when if confronted with big data. Keywords : optimization, classification, single cell of Pap Smear, Correlation based Features Selection, C4.5, Naïve Bayes   Abstrak – Kanker serviks merupakan penyakit yang sangat berbahaya dan pada umumnya menyerang kaum wanita. Deteksi sejak dini melalui metode Pap Smear merupakan salah satu cara untuk mencegah penyakit ini berkembang didalam saluran serviks wanita. Berdasarkan hasil dari metode Pap Smear, didapatkanlah data sel tunggal yang kini dikenal dengan data herlev. Data ini, kemudian dijadikan acuan dalam penelitian oleh para ahli dewasa ini untuk menemukan tingkat klasifikasi terbaik dari masing-masing kelas kanker serviks. Metode Decision tree C4.5 dan Naïve Bayes terbukti memberikan hasil yang terbaik pada ujicoba data herlev sebanyak 280 data dengan dukungan dari metode optimasi Correlation based Features Selection(CFS. Permasalahan

Synthesis and Application of Acid Dyes Based on 3-(4-Aminophenyl-5-benzylidene-2-substituted phenyl-3, 5-dihydroimidazol-4-one

Directory of Open Access Journals (Sweden)

Devang N. Wadia

2008-01-01

Full Text Available A series of eight novel heterocyclic based monoazo acid dyes were synthesized using various substituted imidazol-4-one as diazo component and coupled with various amino-napthol sulphonic acids. The resultant dyes were characterized using standard spectroscopic methods and then dyeing performance on wool fabric was assessed. Final results concluded that exhaustion (%E of the dyes on wool fibers increased with decreasing pH of application and that fixation (%F of the dyes on wool fibers increased with increasing pH of application and the highest total fixation efficiency was achieved at pH 5. Wash and light fastness properties of prepared dyes showed encouraging results.

Effects of the F4TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Ching-Lin Fan

2016-01-01

Full Text Available In this paper, the top-contact (TC pentacene-based organic thin-film transistor (OTFT with a tetrafluorotetracyanoquinodimethane (F4TCNQ-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F4TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance on the thickness of the F4TCNQ-doped pentacene interlayer is weaker than that on a Teflon interlayer. Therefore, a molecular doping-type F4TCNQ-doped pentacene interlayer is a suitable carrier injection layer that can improve the TC-OTFT performance and facilitate obtaining a stable process window.

Effects of the F4TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors

Science.gov (United States)

Fan, Ching-Lin; Lin, Wei-Chun; Chang, Hsiang-Sheng; Lin, Yu-Zuo; Huang, Bohr-Ran

2016-01-01

In this paper, the top-contact (TC) pentacene-based organic thin-film transistor (OTFT) with a tetrafluorotetracyanoquinodimethane (F4TCNQ)-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F4TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance on the thickness of the F4TCNQ-doped pentacene interlayer is weaker than that on a Teflon interlayer. Therefore, a molecular doping-type F4TCNQ-doped pentacene interlayer is a suitable carrier injection layer that can improve the TC-OTFT performance and facilitate obtaining a stable process window. PMID:28787845

Optimization of PAM-4 transmitters based on lumped silicon photonic MZMs for high-speed short-reach optical links.

Science.gov (United States)

Zhou, Shiyu; Wu, Hsin-Ta; Sadeghipour, Khosrov; Scarcella, Carmelo; Eason, Cormac; Rensing, Marc; Power, Mark J; Antony, Cleitus; O'Brien, Peter; Townsend, Paul D; Ossieur, Peter

2017-02-20

We demonstrate how to optimize the performance of PAM-4 transmitters based on lumped Silicon Photonic Mach-Zehnder Modulators (MZMs) for short-reach optical links. Firstly, we analyze the trade-off that occurs between extinction ratio and modulation loss when driving an MZM with a voltage swing less than the MZM's Vπ. This is important when driver circuits are realized in deep submicron CMOS process nodes. Next, a driving scheme based upon a switched capacitor approach is proposed to maximize the achievable bandwidth of the combined lumped MZM and CMOS driver chip. This scheme allows the use of lumped MZM for high speed optical links with reduced RF driver power consumption compared to the conventional approach of driving MZMs (with transmission line based electrodes) with a power amplifier. This is critical for upcoming short-reach link standards such as 400Gb/s 802.3 Ethernet. The driver chip was fabricated using a 65nm CMOS technology and flip-chipped on top of the Silicon Photonic chip (fabricated using IMEC's ISIPP25G technology) that contains the MZM. Open eyes with 4dB extinction ratio for a 36Gb/s (18Gbaud) PAM-4 signal are experimentally demonstrated. The electronic driver chip has a core area of only 0.11mm2 and consumes 236mW from 1.2V and 2.4V supply voltages. This corresponds to an energy efficiency of 6.55pJ/bit including Gray encoder and retiming, or 5.37pJ/bit for the driver circuit only.

Alternative bases to 4-tert-butylpyridine for dye-sensitized solar cells employing copper redox mediator

Czech Academy of Sciences Publication Activity Database

Ferdowsi, P.; Saygili, Y.; Zakeeruddin, S. M.; Mokhtari, J.; Grätzel, M.; Hagfeldt, A.; Kavan, Ladislav

2018-01-01

Roč. 265, MAR 1 (2018), s. 194-201 ISSN 0013-4686 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : electrolytes * efficient * cathodes * shuttle * Dye-sensitized solar cells * Copper(II/I) redox mediators * Pyridine bases * Electrochemical characterization Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.798, year: 2016

Differentiation of F4 receptor profiles in pigs based on their mucin 4 polymorphism, responsiveness to oral F4 immunization and in vitro binding of F4 to villi.

Science.gov (United States)

Nguyen, V U; Goetstouwers, T; Coddens, A; Van Poucke, M; Peelman, L; Deforce, D; Melkebeek, V; Cox, E

2013-03-15

F4(+) enterotoxigenic Escherichia coli (F4(+) ETEC) are an important cause of diarrhoea and mortality in piglets. F4(+) ETEC use their F4 fimbriae to adhere to specific receptors (F4Rs) on small intestinal brush borders, resulting in colonization of the small intestine. To prevent pigs from post-weaning diarrhoea, pigs should be vaccinated during the suckling period. Previously, we demonstrated that F4acR(+), but not F4acR(-) piglets could be orally immunized with purified F4 fimbriae resulting in a protective immunity against F4(+) ETEC infections, indicating that this immune response was F4R dependent. Recently, aminopeptidase N has been identified as a glycoprotein receptor important for this oral immune response. However, in some oral immunization experiments, a few F4acR(+) piglets did not show an antibody response upon oral immunization, suggesting additional receptors. Therefore, the binding profile of F4 to brush border membrane (glyco)proteins was determined for pigs differing in F4-specific antibody response upon oral immunization, in in vitro adhesion of F4(+)E. coli to small intestinal villi, and in Muc4 genotype. Six groups of pigs could be identified. Only two groups positive in all three assays showed two high molecular weight (MW) glycoprotein bands (>250kDa) suggesting that these high MW bands are linked to the MUC4 susceptible genotype. The fact that these bands were absent in the MUC4 resistant group which showed a positive immune response against F4 and was positive in the adhesion test confirm that at least one or perhaps more other F4Rs exist. Interestingly, two pigs that were positive in the villous adhesion assay did not show an immune response against F4 fimbriae. This suggests that a third receptor category might exist which allows the bacteria to adhere but does not allow effective immunization with soluble F4 fimbriae. Future research will be necessary to confirm or reveal the identity of these receptors. Copyright © 2012 Elsevier B

Synthesis of monodisperse MFe{sub 2}O{sub 4} (M = Fe and Zn) nanoparticles for polydiethylsiloxane-based ferrofluid with a solvothermal method

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei [State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Provincial Key Laboratory of Photovoltaics Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Laboratory of Nanophotonic Functional Materials and Devices, Institute of Optoelectronic Materials and Technology, South China Normal University, Guangzhou 510631 (China); Zhuang, Lin, E-mail: stszhl@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Provincial Key Laboratory of Photovoltaics Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Zhang, Yong [Laboratory of Nanophotonic Functional Materials and Devices, Institute of Optoelectronic Materials and Technology, South China Normal University, Guangzhou 510631 (China); Shen, Hui [State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Provincial Key Laboratory of Photovoltaics Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2015-09-15

Highlights: • MFe{sub 2}O{sub 4} nanoparticles were synthesized through a facile solvothermal method. • The relationship between viscosity and temperature of the polydiethylsiloxane-based ferrofluid is discussed. • Fe{sub 3}O{sub 4} nanoparticles have a saturation magnetization of 73.06 emu/g at room temperature. - Abstract: Monodisperse MFe{sub 2}O{sub 4} (M = Fe, Zn) nanoparticles were successfully synthesized for the application of polydiethylsiloxane-based (PDES) ferrofluids (FFs) via a novel solvothermal method, with which 1-octanol and 1-octanamine act as binary solvent, oleic acid (OA) as the surfactant and metal acetylacetonate [M(acac){sub 3}](M = Fe and Zn) as the metal source. X-ray diffractometer confirms that the resultant nanoparticles are pure MFe{sub 2}O{sub 4} with a spinel structure. Infrared spectroscopy indicates that oleic acid is bound to the surface of MFe{sub 2}O{sub 4} through a covalent bond between carboxylate (COO{sup −}) and metal cations. The ratio of 1-octanol and 1-octanamine plays a key role in the formation of the sphere-shaped morphology. Transmission electron microscopy (TEM) images confirm that the Fe{sub 3}O{sub 4} particles are of 4–11 nm with good monodispersity and a narrow size distribution. The saturation magnetization of Fe{sub 3}O{sub 4} nanoparticles with sizes of 7 nm can reach up to 73.06 emu/g. Polydiethylsiloxane-based (PDES) FFs show relatively smaller changes of the viscosity with low temperatures (from −7 to 20 °C) than the polydimethylsiloxane-based (PDMS) FFs. For FFs applications, the relationship between viscosity and temperature is also discussed.

Adsorption of methyl violet from aqueous solution using gum xanthan/Fe3O4 based nanocomposite hydrogel

CSIR Research Space (South Africa)

Mittal, H

2016-08-01

Full Text Available This research paper reports the utilization of gum xanthan-grafted-polyacrylic acid and Fe(sub3)O(sub4) magnetic nanoparticles based nanocomposite hydrogel (NCH) for the highly effective adsorption of methyl violet (MV) from aqueous solution...

4-CM2 CuInGaSe2 based solar cells

International Nuclear Information System (INIS)

Devaney, W.E.; Stewart, J.M.; Chen, W.S.

1990-01-01

This paper reports that polycrystalline thin-film solar cells with the structure ZnO/CdZnS/CuInGaSe 2 have been fabricated with larger single cell areas than have been previously reported. A cell of area 4-cm 2 has been made with an Am1.5, 100 mW/cm 2 total area conversion efficiency of (11.1% 912.0% active area) and AMO conversion efficiency of 10.0% (10.9% active area). The CuInGaSe 2 layer had a gallium to indium ratio of 0.26:0.74 with a band gap of approximately 1.15 eV. The cells use an isolated tab design for the negative (grid) contact, demonstrating the ability to pattern the semiconductor layers. Such CuInGaSe 2 based cells may be suitable both for large area terrestrial applications and for single-junction space cell applications

Investigation based on nano-electromechanical system double Si3N4 resonant beam pressure sensor.

Science.gov (United States)

Yang, Chuan; Guo, Can; Yuan, Xiaowei

2011-12-01

This paper presents a type of NEMS (Nano-Electromechanical System) double Si3N4 resonant beams pressure sensor. The mathematical models are established in allusion to the Si3N4 resonant beams and pressure sensitive diaphragm. The distribution state of stress has been analyzed theoretically based on the mathematical model of pressure sensitive diaphragm; from the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm was optimized and then the dominance observed after the double resonant beams are adopted is illustrated. From the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm is optimized, illustrating advantages in the adoption of double resonant beams. The capability of the optimized sensor was generally analyzed using the ANSYS software of finite element analysis. The range of measured pressure is 0-400 Kpa, the coefficient of linearity correlation is 0.99346, and the sensitivity of the sensor is 498.24 Hz/Kpa, higher than the traditional sensors. Finally the processing techniques of the sensor chip have been designed with sample being successfully processed.

Sea Ice Drift Monitoring in the Bohai Sea Based on GF4 Satellite

Science.gov (United States)

Zhao, Y.; Wei, P.; Zhu, H.; Xing, B.

2018-04-01

The Bohai Sea is the inland sea with the highest latitude in China. In winter, the phenomenon of freezing occurs in the Bohai Sea due to frequent cold wave influx. According to historical records, there have been three serious ice packs in the Bohai Sea in the past 50 years which caused heavy losses to our economy. Therefore, it is of great significance to monitor the drift of sea ice and sea ice in the Bohai Sea. The GF4 image has the advantages of short imaging time and high spatial resolution. Based on the GF4 satellite images, the three methods of SIFT (Scale invariant feature - the transform and Scale invariant feature transform), MCC (maximum cross-correlation method) and sift combined with MCC are used to monitor sea ice drift and calculate the speed and direction of sea ice drift, the three calculation results are compared and analyzed by using expert interpretation and historical statistical data to carry out remote sensing monitoring of sea ice drift results. The experimental results show that the experimental results of the three methods are in accordance with expert interpretation and historical statistics. Therefore, the GF4 remote sensing satellite images have the ability to monitor sea ice drift and can be used for drift monitoring of sea ice in the Bohai Sea.

Movie Popularity Classification based on Inherent Movie Attributes using C4.5, PART and Correlation Coefficient

DEFF Research Database (Denmark)

Ibnal Asad, Khalid; Ahmed, Tanvir; Rahman, Md. Saiedur

2012-01-01

Abundance of movie data across the internet makes it an obvious candidate for machine learning and knowledge discovery. But most researches are directed towards bi-polar classification of movie or generation of a movie recommendation system based on reviews given by viewers on various internet...... sites. Classification of movie popularity based solely on attributes of a movie i.e. actor, actress, director rating, language, country and budget etc. has been less highlighted due to large number of attributes that are associated with each movie and their differences in dimensions. In this paper, we...... propose classification scheme of pre-release movie popularity based on inherent attributes using C4.S and PART classifier algorithm and define the relation between attributes of post release movies using correlation coefficient....

Neuropsychologic status at the age 4 years and atopy in a population-based birth cohort.

Science.gov (United States)

Julvez, J; Torrent, M; Guxens, M; Antó, J M; Guerra, S; Sunyer, J

2009-09-01

Mental health has been reported to be associated with allergy, but only a few cohort studies have assessed if neurodevelopment predicts atopy. To investigate if neurobehavioral status of healthy 4-year-old children was associated with specific immunoglobulin E (IgE) at the same age and skin prick test results 2 years later. A population-based birth cohort enrolled 482 children, 422 of them (87%) provided neurobehavioral data, 341 (71%) had specific IgE measured at the age of 4 years; and 395 (82%) had skin prick tests completed at the age of 6 years. Atopy was defined as IgE levels higher than 0.35 kU/l to any of the three tested allergens at the age of 4 or as a positive skin prick test to any of the six tested allergens at the age of 6. McCarthy Scales of Child Abilities and California Preschool Social Competence Scale were the psychometric instruments used. Twelve percent of children at the age of 4 and 17% at the age of 6 were atopic. Neurobehavioral scores were negatively associated with 6-year-old atopy after adjustment for socio-demographic and allergic factors, A relative risk of 3.06 (95% CI: 1.30-7.24) was associated with the lowest tertile (scorings eczema at the age of 6, but not at the age of 4, were associated with neurodevelopment at the age of 4. Neuropsychologic functioning and later atopy are negatively associated in preschool age children.

1.2.4. Synthesis, crystal structure and thermal stability property of Ni(aze(4,4′ –bipy(H2O based on longer-spanning azelaic acid and 4,4′ -bipyridine ligands

Directory of Open Access Journals (Sweden)

Ge Song, Feng Ying Bai*, Yan Xie, Yong Heng Xing.

2014-04-01

Full Text Available Abstract: One new three-dimensional (3D supramolecular longer-spanning azelaic acid (H2aze complex: Ni(aze(4,4′– bipy(H2O (4,4′-bipy = 4,4′-bipyridine has been synthesized using hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, UV spectrum, powder X-ray diffraction, TG analysis and single crystal X–ray diffraction. Structural analysis reveals that the title complex is six-coordinate and connected by the azelaic acid and 4,4′-bipy ligands to generate a 2D planar structure, further linked through the interaction of hydrogen bond of C–H···O to form a 3D supramolecular structure . Supporting information: FT-IR, UV-Vis, X-Ray, Cif file

Atom-probe field-ion microscopy investigation of CMSX-4 Ni-base superalloy laser beam welds

International Nuclear Information System (INIS)

Babu, S.S.; David, S.A.; Vitek, J.M.; Miller, M.K.

1996-01-01

CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy (APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped γ' precipitates (0.65 to 0.75 volume fraction) within the γ matrix. APFIM compositions of the γ and γ' phases were found to be different from those in the base metal. Concentration profiles across the γ and γ' phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the γ phase. Calculated lattice misfits near the γ/γ' interface in the welds are positive values compared to the negative values for base metal. (orig.)

Effects of the F4TCNQ-Doped Pentacene Interlayers on Performance Improvement of Top-Contact Pentacene-Based Organic Thin-Film Transistors

OpenAIRE

Ching-Lin Fan; Wei-Chun Lin; Hsiang-Sheng Chang; Yu-Zuo Lin; Bohr-Ran Huang

2016-01-01

In this paper, the top-contact (TC) pentacene-based organic thin-film transistor (OTFT) with a tetrafluorotetracyanoquinodimethane (F4TCNQ)-doped pentacene interlayer between the source/drain electrodes and the pentacene channel layer were fabricated using the co-evaporation method. Compared with a pentacene-based OTFT without an interlayer, OTFTs with an F4TCNQ:pentacene ratio of 1:1 showed considerably improved electrical characteristics. In addition, the dependence of the OTFT performance ...

Monte Carlo application based on GEANT4 toolkit to simulate a laser–plasma electron beam line for radiobiological studies

Energy Technology Data Exchange (ETDEWEB)

Lamia, D., E-mail: debora.lamia@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Russo, G., E-mail: giorgio.russo@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Casarino, C.; Gagliano, L.; Candiano, G.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Labate, L. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Baffigi, F.; Fulgentini, L.; Giulietti, A.; Koester, P.; Palla, D. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); Gizzi, L.A. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Gilardi, M.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR, Segrate (Italy); University of Milano-Bicocca, Milano (Italy)

2015-06-21

We report on the development of a Monte Carlo application, based on the GEANT4 toolkit, for the characterization and optimization of electron beams for clinical applications produced by a laser-driven plasma source. The GEANT4 application is conceived so as to represent in the most general way the physical and geometrical features of a typical laser-driven accelerator. It is designed to provide standard dosimetric figures such as percentage dose depth curves, two-dimensional dose distributions and 3D dose profiles at different positions both inside and outside the interaction chamber. The application was validated by comparing its predictions to experimental measurements carried out on a real laser-driven accelerator. The work is aimed at optimizing the source, by using this novel application, for radiobiological studies and, in perspective, for medical applications. - Highlights: • Development of a Monte Carlo application based on GEANT4 toolkit. • Experimental measurements carried out with a laser-driven acceleration system. • Validation of Geant4 application comparing experimental data with the simulated ones. • Dosimetric characterization of the acceleration system.

BoHV-4-Based Vector Single Heterologous Antigen Delivery Protects STAT1(-/- Mice from Monkeypoxvirus Lethal Challenge.

Directory of Open Access Journals (Sweden)

Valentina Franceschi

2015-06-01

Full Text Available Monkeypox virus (MPXV is the etiological agent of human (MPX. It is an emerging orthopoxvirus zoonosis in the tropical rain forest of Africa and is endemic in the Congo-basin and sporadic in West Africa; it remains a tropical neglected disease of persons in impoverished rural areas. Interaction of the human population with wildlife increases human infection with MPX virus (MPXV, and infection from human to human is possible. Smallpox vaccination provides good cross-protection against MPX; however, the vaccination campaign ended in Africa in 1980, meaning that a large proportion of the population is currently unprotected against MPXV infection. Disease control hinges on deterring zoonotic exposure to the virus and, barring that, interrupting person-to-person spread. However, there are no FDA-approved therapies against MPX, and current vaccines are limited due to safety concerns. For this reason, new studies on pathogenesis, prophylaxis and therapeutics are still of great interest, not only for the scientific community but also for the governments concerned that MPXV could be used as a bioterror agent. In the present study, a new vaccination strategy approach based on three recombinant bovine herpesvirus 4 (BoHV-4 vectors, each expressing different MPXV glycoproteins, A29L, M1R and B6R were investigated in terms of protection from a lethal MPXV challenge in STAT1 knockout mice. BoHV-4-A-CMV-A29LgD106ΔTK, BoHV-4-A-EF1α-M1RgD106ΔTK and BoHV-4-A-EF1α-B6RgD106ΔTK were successfully constructed by recombineering, and their capacity to express their transgene was demonstrated. A small challenge study was performed, and all three recombinant BoHV-4 appeared safe (no weight-loss or obvious adverse events following intraperitoneal administration. Further, BoHV-4-A-EF1α-M1RgD106ΔTK alone or in combination with BoHV-4-A-CMV-A29LgD106ΔTK and BoHV-4-A-EF1α-B6RgD106ΔTK, was shown to be able to protect, 100% alone and 80% in combination, STAT1(-/- mice

Development in Zn4Sb-based thermoelectric materials

DEFF Research Database (Denmark)

Yin, Hao

or thermopower,  the electrical conductivity, the thermal conductivity and T the absolute temperature. The best thermoelectrics are heavily doped semiconductors with high thermoelectric power factors and low thermal conductivities, known as “Phonon Glasses Electrical Crystals”. Zn4Sb3 is one such material......-section. The following part reports the effect of nano-particles on the thermoelectric properties and thermal stability of Zn4Sb3. Though TiO2 nano particles have remarkably enhanced the stability, the thermoelectric performance of all the nano-composites deteriorates. Optimization of the content of the nano...

Comparison of chamber and eddy covariance-based CO2 and CH4 emission estimates in a heterogeneous grass ecosystem on peat

International Nuclear Information System (INIS)

Schrier-Uijl, A.P.; Berendse, F.; Veenendaal, E.M.; Kroon, P.S.; Hensen, A.; Leffelaar, P.A.

2010-08-01

Fluxes of methane (CH4) and carbon dioxide (CO2) estimated by empirical models based on small-scale chamber measurements were compared to large-scale eddy covariance (EC) measurements for CH4 and to a combination of EC measurements and EC-based models for CO2. The experimental area was a flat peat meadow in the Netherlands with heterogeneous source strengths for both greenhouse gases. Two scenarios were used to assess the importance of stratifying the landscape into landscape elements before up-scaling the fluxes measured by chambers to landscape scale: one took the main landscape elements into account (field, ditch edge ditch), the other took only the field into account. Non-linear regression models were used to up-scale the chamber measurements to field emission estimates. EC CO2 respiration consisted of measured night time EC fluxes and modeled day time fluxes using the Arrhenius model. EC CH4 flux estimate was based on daily averages and the remaining data gaps were filled by linear interpolation. The EC and chamber-based estimates agreed well when the three landscape elements were taken into account with 16.5% and 13.0% difference for CO2 respiration and CH4, respectively. However, both methods differed 31.0% and 55.1% for CO2 respiration and CH4 when only field emissions were taken into account when up-scaling chamber measurements to landscape scale. This emphasizes the importance of stratifying the landscape into landscape elements. The conclusion is that small-scale chamber measurements can be used to estimate fluxes of CO2 and CH4 at landscape scale if fluxes are scaled by different landscape elements.

Feasibility, Acceptability, and Preliminary Effectiveness of a 4-week Mindfulness-Based Cognitive Therapy Protocol for Hospital Employees.

Science.gov (United States)

Luberto, Christina M; Wasson, Rachel S; Kraemer, Kristen M; Sears, Richard W; Hueber, Carly; Cotton, Sian

2017-12-01

Hospital employees may experience occupational stress and burnout, which negatively impact quality of life and job performance. Evidence-based interventions implemented within the hospital setting are needed to promote employees' well-being. We offered a 4-week Mindfulness-Based Cognitive Therapy group program for hospital employees, and used a mixed-methods practice-based research approach to explore feasibility, acceptability, and effects on stress and burnout. Participants were 65 hospital employees ( M age = 44.06; 85% white) who participated between September 2015 and January 2016. Participants completed validated measures of stress and burnout before and after the program, and answered open-ended satisfaction questions after the program. Groups consistently enrolled at least 10 participants, but attendance rates declined across sessions (76% at session 2 vs. 54% at session 4) due primarily to work-related scheduling conflicts. The program content was acceptable as evidenced by high perceived value ( M = 9.18 out of 10), homework compliance (51% practicing at least 3 times/week), and qualitative requests for program expansion. There were large, statistically significant decreases in stress (Δ M = 2.1, p strategies to enhance session attendance.