Multilayer-MCTDH approach to the energy transfer dynamics in the LH2 antenna complex

NASA Astrophysics Data System (ADS)

Shibl, Mohamed F.; Schulze, Jan; Al-Marri, Mohammed J.; Kühn, Oliver

2017-09-01

The multilayer multiconfiguration time-dependent Hartree method is used to study the coupled exciton-vibrational dynamics in a high-dimensional nonameric model of the LH2 antenna complex of purple bacteria. The exciton-vibrational coupling is parametrized within the Huang-Rhys model according to phonon and intramolecular vibrational modes derived from an experimental bacteriochlorophyll spectral density. In contrast to reduced density matrix approaches, the Schrödinger equation is solved explicitly, giving access to the full wave function. This facilitates an unbiased analysis in terms of the coupled dynamics of excitonic and vibrational degrees of freedom. For the present system, we identify spectator modes for the B800 to B800 transfer and we find a non-additive effect of phonon and intramolecular vibrational modes on the B800 to B850 exciton transfer.

Elimination of polarity in the carotenoid terminus promotes the exposure of B850-binding sites (Tyr 44, 45) and ANS-mediated energy transfer in LH2 complexes of Rhodobacter sphaeroides.

PubMed

Liu, Yuan; Wu, Yongqiang; Xu, Chunhe

2004-12-10

Carotenoids in the peripheral light-harvesting complexes (LH2) of the green mutant (GM309) of Rhodobacter sphaeroides were identified as containing neurosporenes, which lack the polar CH(3)O group, compared to spheroidenes in native-LH2 of R. sphaeroides 601. After LH2 complexes were treated with 1-anilino-8-naphthalene sulfonate (ANS), new energy transfer pathways from ANS or tryptophan to carotenoids were discovered in both native- and GM309-LH2. The carotenoid fluorescence intensity of GM309-LH2 was greater than that of native-LH2 when bound with ANS, suggesting that the elimination of polarity in the neurosporene increases the energy transfer from ANS to carotenoid. The fact that two alpha-tyrosines (alpha-Tyr 44, 45, B850-binding sites) in each alpha-apoprotein of GM309-LH2 were more easily modified than those of native-LH2 by N-acetylimidazole (NAI) indicates that the elimination of polarity in the neurosporene terminus increases the exposure of these sites to solution.

Extension of Light-Harvesting Ability of Photosynthetic Light-Harvesting Complex 2 (LH2) through Ultrafast Energy Transfer from Covalently Attached Artificial Chromophores.

PubMed

Yoneda, Yusuke; Noji, Tomoyasu; Katayama, Tetsuro; Mizutani, Naoto; Komori, Daisuke; Nango, Mamoru; Miyasaka, Hiroshi; Itoh, Shigeru; Nagasawa, Yutaka; Dewa, Takehisa

2015-10-14

Introducing appropriate artificial components into natural biological systems could enrich the original functionality. To expand the available wavelength range of photosynthetic bacterial light-harvesting complex 2 (LH2 from Rhodopseudomonas acidophila 10050), artificial fluorescent dye (Alexa Fluor 647: A647) was covalently attached to N- and C-terminal Lys residues in LH2 α-polypeptides with a molar ratio of A647/LH2 ≃ 9/1. Fluorescence and transient absorption spectroscopies revealed that intracomplex energy transfer from A647 to intrinsic chromophores of LH2 (B850) occurs in a multiexponential manner, with time constants varying from 440 fs to 23 ps through direct and B800-mediated indirect pathways. Kinetic analyses suggested that B800 chromophores mediate faster energy transfer, and the mechanism was interpretable in terms of Förster theory. This study demonstrates that a simple attachment of external chromophores with a flexible linkage can enhance the light harvesting activity of LH2 without affecting inherent functions of energy transfer, and can achieve energy transfer in the subpicosecond range. Addition of external chromophores, thus, represents a useful methodology for construction of advanced hybrid light-harvesting systems that afford solar energy in the broad spectrum.

Spectral heterogeneity and carotenoid-to-bacteriochlorophyll energy transfer in LH2 light-harvesting complexes from Allochromatium vinosum.

PubMed

Magdaong, Nikki M; LaFountain, Amy M; Hacking, Kirsty; Niedzwiedzki, Dariusz M; Gibson, George N; Cogdell, Richard J; Frank, Harry A

2016-02-01

Photosynthetic organisms produce a vast array of spectral forms of antenna pigment-protein complexes to harvest solar energy and also to adapt to growth under the variable environmental conditions of light intensity, temperature, and nutrient availability. This behavior is exemplified by Allochromatium (Alc.) vinosum, a photosynthetic purple sulfur bacterium that produces different types of LH2 light-harvesting complexes in response to variations in growth conditions. In the present work, three different spectral forms of LH2 from Alc. vinosum, B800-820, B800-840, and B800-850, were isolated, purified, and examined using steady-state absorption and fluorescence spectroscopy, and ultrafast time-resolved absorption spectroscopy. The pigment composition of the LH2 complexes was analyzed by high-performance liquid chromatography, and all were found to contain five carotenoids: lycopene, anhydrorhodovibrin, spirilloxanthin, rhodopin, and rhodovibrin. Spectral reconstructions of the absorption and fluorescence excitation spectra based on the pigment composition revealed significantly more spectral heterogeneity in these systems compared to LH2 complexes isolated from other species of purple bacteria. The data also revealed the individual carotenoid-to-bacteriochlorophyll energy transfer efficiencies which were correlated with the kinetic data from the ultrafast transient absorption spectroscopic experiments. This series of LH2 complexes allows a systematic exploration of the factors that determine the spectral properties of the bound pigments and control the rate and efficiency of carotenoid-to-bacteriochlorophyll energy transfer.

Tryptophan-to-Tryptophan Energy Transfer in UV-B photoreceptor UVR8

NASA Astrophysics Data System (ADS)

Li, Xiankun; Zhong, Dongping

UVR8 (UV RESISTANCE LOCUS 8) protein is a UV-B photoreceptor in high plants. UVR8 is a homodimer that dissociates into monomers upon UV-B irradiation (280 nm to 315 nm), which triggers various protective mechanisms against UV damages. Uniquely, UVR8 does not contain any external chromophores and utilizes the UV-absorbing natural amino acid tryptophan (Trp) to perceive UV-B. Each UVR8 monomer has 14 tryptophan residues. However, only 2 epicenter Trp (W285 W233) are critical to the light induced dimer-to-monomer transformation. Here, we revealed, using site-directed mutagenesis and spectroscopy, a striking energy flow network, in which other tryptophan chromophores serve as antenna to transfer excitation energy to epicenter Trp, greatly enhancing UVR8 light-harvesting efficiency. Furthermore, Trp-to-Trp energy transfer rates were measured and agree well with theoretical values.

10 CFR 850.13 - Compliance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Compliance. 850.13 Section 850.13 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Administrative Requirements § 850.13 Compliance. (a) The responsible employer must conduct activities in compliance with its CBDPP. (b) The responsible...

10 CFR 850.13 - Compliance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Compliance. 850.13 Section 850.13 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Administrative Requirements § 850.13 Compliance. (a) The responsible employer must conduct activities in compliance with its CBDPP. (b) The responsible...

10 CFR 850.21 - Hazard assessment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Hazard assessment. 850.21 Section 850.21 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.21 Hazard... with the greatest risks of exposure are evaluated first. (b) The responsible employer must ensure that...

Carotenoid-to-bacteriochlorophyll energy transfer through vibronic coupling in LH2 from Phaeosprillum molischianum.

PubMed

Thyrhaug, Erling; Lincoln, Craig N; Branchi, Federico; Cerullo, Giulio; Perlík, Václav; Šanda, František; Lokstein, Heiko; Hauer, Jürgen

2018-03-01

The peripheral light-harvesting antenna complex (LH2) of purple photosynthetic bacteria is an ideal testing ground for models of structure-function relationships due to its well-determined molecular structure and ultrafast energy deactivation. It has been the target for numerous studies in both theory and ultrafast spectroscopy; nevertheless, certain aspects of the convoluted relaxation network of LH2 lack a satisfactory explanation by conventional theories. For example, the initial carotenoid-to-bacteriochlorophyll energy transfer step necessary on visible light excitation was long considered to follow the Förster mechanism, even though transfer times as short as 40 femtoseconds (fs) have been observed. Such transfer times are hard to accommodate by Förster theory, as the moderate coupling strengths found in LH2 suggest much slower transfer within this framework. In this study, we investigate LH2 from Phaeospirillum (Ph.) molischianum in two types of transient absorption experiments-with narrowband pump and white-light probe resulting in 100 fs time resolution, and with degenerate broadband 10 fs pump and probe pulses. With regard to the split Q x band in this system, we show that vibronically mediated transfer explains both the ultrafast carotenoid-to-B850 transfer, and the almost complete lack of transfer to B800. These results are beyond Förster theory, which predicts an almost equal partition between the two channels.

Energy and Electron Transfer in Enhanced Two-Photon-Absorbing Systems with Triplet Cores

PubMed Central

Finikova, Olga S.; Troxler, Thomas; Senes, Alessandro; DeGrado, William F.; Hochstrasser, Robin M.; Vinogradov, Sergei A.

2008-01-01

Enhanced two-photon-absorbing (2PA) systems with triplet cores are currently under scrutiny for several biomedical applications, including photodynamic therapy (PDT) and two-photon microscopy of oxygen. The performance of so far developed molecules, however, is substantially below expected. In this study we take a detailed look at the processes occurring in these systems and propose ways to improve their performance. We focus on the interchromophore distance tuning as a means for optimization of two-photon sensors for oxygen. In these constructs, energy transfer from several 2PA chromophores is used to enhance the effective 2PA cross section of phosphorescent metalloporphyrins. Previous studies have indicated that intramolecular electron transfer (ET) can act as an effective quencher of phosphorescence, decreasing the overall sensor efficiency. We studied the interplay between 2PA, energy transfer, electron transfer, and phosphorescence emission using Rhodamine B-Pt tetrabenzoporphyrin (RhB-PtTBP) adducts as model compounds. 2PA cross sections (σ2) of tetrabenzoporphyrins (TBPs) are in the range of several tens of GM units (near 800 nm), making TBPs superior 2PA chromophores compared to regular porphyrins (σ2 values typically 1-2 GM). Relatively large 2PA cross sections of rhodamines (about 200 GM in 800-850 nm range) and their high photostabilities make them good candidates as 2PA antennae. Fluorescence of Rhodamine B (λfl = 590 nm, ϕfl = 0.5 in EtOH) overlaps with the Q-band of phosphorescent PtTBP (λabs = 615 nm, ϵ = 98 000 M-1 cm-1, ϕp ∼ 0.1), suggesting that a significant amplification of the 2PA-induced phosphorescence via fluorescence resonance energy transfer (FRET) might occur. However, most of the excitation energy in RhB-PtTBP assemblies is consumed in several intramolecular ET processes. By installing rigid nonconducting decaproline spacers (Pro10) between RhB and PtTBP, the intramolecular ETs were suppressed, while the chromophores were kept

Discrepancy between experimental and theoretical excitation transfer rates in LH2 bacteriochlorophyll-protein complexes of purple bacteria.

PubMed

Borisov, A Y

2008-02-01

Discrepancy is revealed between the values of excitation transfer times measured experimentally, and those calculated, for the atomic structures of B800 --> B850 bacteriochlorophylls within the LH2 light-harvesting pigment-protein complex of the purple bacterium Rhodopseudomonas acidophila. The value 2.9-3.2 ps for the B800 --> B850 excitation transfer, calculated on the basis of atomic structure of LH2, is about 4-times longer than that measured for this bacterium (0.7 ps). This discrepancy appears common in at least two purple bacteria. Possible sources responsible for this discrepancy are discussed. It may either signify some drawback/s/ in our notions about the precise in vivo structure of LH2 complexes, for example, possible changes of LH2 structure during crystallization, or it may reflect our ignorance of some mechanisms involved in excitation migration.

Conformational Complexity in the LH2 Antenna of the Purple Sulfur Bacterium Allochromatium vinosum Revealed by Hole-Burning Spectroscopy.

PubMed

Kell, Adam; Jassas, Mahboobe; Acharya, Khem; Hacking, Kirsty; Cogdell, Richard J; Jankowiak, Ryszard

2017-06-15

This work discusses the protein conformational complexity of the B800-850 LH2 complexes from the purple sulfur bacterium Allochromatium vinosum, focusing on the spectral characteristics of the B850 chromophores. Low-temperature B850 absorption and the split B800 band shift blue and red, respectively, at elevated temperatures, revealing isosbestic points. The latter indicates the presence of two (unresolved) conformations of B850 bacteriochlorophylls (BChls), referred to as conformations 1 and 2, and two conformations of B800 BChls, denoted as B800 R and B800 B . The energy differences between average site energies of conformations 1 and 2, and B800 R and B800 B are similar (∼200 cm -1 ), suggesting weak and strong hydrogen bonds linking two major subpopulations of BChls and the protein scaffolding. Although conformations 1 and 2 of the B850 chromophores, and B800 R and B800 B , exist in the ground state, selective excitation leads to 1 → 2 and B800 R → B800 B phototransformations. Different static inhomogeneous broadening is revealed for the lowest energy exciton states of B850 (fwhm ∼195 cm -1 ) and B800 R (fwhm ∼140 cm -1 ). To describe the 5 K absorption spectrum and the above-mentioned conformations, we employ an exciton model with dichotomous protein conformation disorder. We show that both experimental data and the modeling study support a two-site model with strongly and weakly hydrogen-bonded B850 and B800 BChls, which under illumination undergo conformational changes, most likely caused by proton dynamics.

Polaronic effects at finite temperatures in the B850 ring of the LH2 complex.

PubMed

Chorošajev, Vladimir; Rancova, Olga; Abramavicius, Darius

2016-03-21

Energy transfer and relaxation dynamics in the B850 ring of LH2 molecular aggregates are described, taking into account the polaronic effects, by a stochastic time-dependent variational approach. We explicitly include the finite temperature effects in the model by sampling the initial conditions of the vibrational states randomly. This is in contrast to previous applications of the variational approach, which consider only the zero-temperature case. The method allows us to obtain both the microscopic dynamics at the single-wavefunction level and the thermally averaged picture of excitation relaxation over a wide range of temperatures. Spectroscopic observables such as temperature dependent absorption and time-resolved fluorescence spectra are calculated. Microscopic wavefunction evolution is quantified by introducing the exciton participation (localization) length and the exciton coherence length. Their asymptotic temperature dependence demonstrates that the environmental polaronic effects range from exciton self-trapping and excitonic polaron formation at low temperatures to thermally induced state delocalization and decoherence at high temperatures. While the transition towards the polaronic state can be observed on the wavefunction level, it does not produce a discernible effect on the calculated spectroscopic observables.

10 CFR 850.24 - Exposure monitoring.

Code of Federal Regulations, 2014 CFR

2014-01-01

... activities properly. (b) Initial monitoring. The responsible employer must perform initial monitoring in... 10 Energy 4 2014-01-01 2014-01-01 false Exposure monitoring. 850.24 Section 850.24 Energy... Exposure monitoring. (a) General. The responsible employer must ensure that: (1) Exposure monitoring is...

10 CFR 850.24 - Exposure monitoring.

Code of Federal Regulations, 2011 CFR

2011-01-01

... activities properly. (b) Initial monitoring. The responsible employer must perform initial monitoring in... 10 Energy 4 2011-01-01 2011-01-01 false Exposure monitoring. 850.24 Section 850.24 Energy... Exposure monitoring. (a) General. The responsible employer must ensure that: (1) Exposure monitoring is...

10 CFR 850.24 - Exposure monitoring.

Code of Federal Regulations, 2012 CFR

2012-01-01

... activities properly. (b) Initial monitoring. The responsible employer must perform initial monitoring in... 10 Energy 4 2012-01-01 2012-01-01 false Exposure monitoring. 850.24 Section 850.24 Energy... Exposure monitoring. (a) General. The responsible employer must ensure that: (1) Exposure monitoring is...

10 CFR 850.24 - Exposure monitoring.

Code of Federal Regulations, 2010 CFR

2010-01-01

... activities properly. (b) Initial monitoring. The responsible employer must perform initial monitoring in... 10 Energy 4 2010-01-01 2010-01-01 false Exposure monitoring. 850.24 Section 850.24 Energy... Exposure monitoring. (a) General. The responsible employer must ensure that: (1) Exposure monitoring is...

10 CFR 850.24 - Exposure monitoring.

Code of Federal Regulations, 2013 CFR

2013-01-01

... activities properly. (b) Initial monitoring. The responsible employer must perform initial monitoring in... 10 Energy 4 2013-01-01 2013-01-01 false Exposure monitoring. 850.24 Section 850.24 Energy... Exposure monitoring. (a) General. The responsible employer must ensure that: (1) Exposure monitoring is...

[Influence of LDAO on the conformation and release of bacteriochlorophyll of peripheral light-harvesting complex (LH2) from Rhodobacter azotoformans].

PubMed

Zhao, Gen-gui; Dong, Yan-min; Yang, Su-ping; Jiao, Nian-zhi; Qu, Yin-bo

2010-10-01

The aim of this study is to reveal the interaction relationships between lauryl dimethylamine N-oxide (LDAO) and peripheral light-harvesting complex (LH2) as well as the influence of LDAO on structure and function of LH2. In the present work, the effects of LDAO on the conformation and release processes of bacteriochlorophyll (BChl) of LH2 when incubated under different temperature and pH in the presence and absence of LDAO were investigated by spectroscopy. The results indicated that (1) the presence of LDAO resulted in alterations in the conformation, alpha-helix content, and spectra of Tyr and B850 band of LH2 at room temperature and pH 8.0. Moreover, energy transfer efficiency of LH2 was enhanced markedly in the presence of LDAO. (2) At 60 degrees C, both the B800 and B850 band of LH2 were released and transited into free BChl at pH 8.0. However, the release rates of bacteriochlorophylls of B800 and B850 band from LH2 were slowed down and the release processes were changed when incubated in the presence of LDAO. Hence, the stability of LH2 was improved in the presence of LDAO. (3) The accelerated release processes of bacteriochlorophylls of B800 and B850 band of LH2 were induced to transform into bacteriopheophytin (BPhe) and free BChl by LDAO in strong acid and strong alkalic solution at room temperature. However, the kinetic patterns of the B800 and B850 band were remarkably different. The release and self-assemble processes of B850 in LH2 were observed in strong acid solution without LDAO. Therefore, the different release behaviors of B800 and B850 of LH2 are induced by LDAO under different extreme environmental conditions.

High Bandwidth-Efficiency Resonant Cavity Enhanced Schottky Photodiodes for 800-850 nm Wavelength Operation

DTIC Science & Technology

1998-05-25

at least 50 nm wide centered around 830 nm wavelength. The layers are grown by molecular beam epitaxy on a semi- insulating GaAs substrate. The...limited by the material properties. With the advent of GaAs vertical-cavity surface-emitting lasers ~ VCSEL !,2 the 800–850 nm wavelength range has recently

Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuzaki, Satoshi

2001-01-01

This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application ofmore » NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Q y-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophyll a (BChl a) molecules are provided. General conclusions are given in Chapter 5. A version of the hole spectrum simulation program written by the candidate for the FMO complex study (Chapter 3) is included as an appendix. The references for each chapter are given at the end of each chapter.« less

Sol-gel syntheses, luminescence, and energy transfer properties of α-GdB5O9:Ce(3+)/Tb(3+) phosphors.

PubMed

Sun, Xiaorui; Gao, Wenliang; Yang, Tao; Cong, Rihong

2015-02-07

Sol-gel method was applied to prepare homogenous and highly crystalline phosphors with the formulas α-GdB5O9:xTb(3+) (0 ≤ x ≤ 1), α-Gd1-xCexB5O9 (0 ≤ x ≤ 0.40), α-GdB5O9:xCe(3+), 0.30Tb(3+) (0 ≤ x ≤ 0.15) and α-GdB5O9:0.20Ce(3+), xTb(3+) (0 ≤ x ≤ 0.10). The success of the syntheses was proved by the linear shrinkage or expansion of the cell volumes against the substitution contents. In α-GdB5O9:xTb(3+), an efficient energy transfer from Gd(3+) to Tb(3+) was observed and there was no luminescence quenching. The exceptionally high efficiency of the f-f excitations of Tb(3+) implies that these phosphors may be good green-emitting UV-LED phosphors. For α-Gd1-xCexB5O9, Ce(3+) absorbs the majority of the energy and transfers it to Gd(3+). Therefore, the co-doping of Ce(3+) and Tb(3+) leads to a significant enhancement in the green emission of Tb(3+). Our current results together with the study on α-GdB5O9:xEu(3+) in the literature indicate that α-GdB5O9 is a good phosphor host with advantages including controllable preparation, diverse cationic doping, the absence of concentration quenching, and effective energy transfer.

Path induced coherent energy transfer in light-harvesting complexes in purple bacteria

NASA Astrophysics Data System (ADS)

Sun, Kewei; Ye, Jun; Zhao, Yang

2014-09-01

Features of path dependent energy transfer in a dual-ring light-harvesting (LH2) complexes (B850) system have been examined in detail systematically. The Frenkel-Dirac time dependent variational method with the Davydov D1 Ansatz is employed with detailed evolution of polaron dynamics in real space readily obtained. It is found that the phase of the transmission amplitude through the LH2 complexes plays an important role in constructing the coherent excitonic energy transfer. It is also found that the symmetry breaking caused by the dimerization of bacteriochlorophylls and coherence or correlation between two rings will be conducive in enhancing the exciton transfer efficiency.

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 2 2013-01-01 2013-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 2 2014-01-01 2014-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 2 2012-01-01 2012-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 2 2011-01-01 2011-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

12 CFR Appendix B to Subpart B of... - Article 4A, Funds Transfers

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Article 4A, Funds Transfers B Appendix B to...—Article 4A, Funds Transfers Part 1—Subject Matter and Definitions Section 4A-101. Short Title This Article... otherwise provided in section 4A-108, this Article applies to funds transfers defined in section 4A-104...

Transient absorption study of two-photon excitation mechanism in the LH2 complex from purple bacterium Rhodobacter sphaeroides.

PubMed

Stepanenko, Ilya; Kompanetz, Viktor; Makhneva, Zoya; Chekalin, Sergey; Moskalenko, Andrei; Razjivin, Andrei

2012-03-08

The mechanism of two-photon excitation of a peripheral light-harvesting complex LH2 (B800-850) from purple bacterium Rhodobacter sphaeroides was explained on the basis of femtosecond transient absorption data. Fast bleaching of the B850 absorption band was measured under two-photon excitation by 1350 nm femtosecond pulses, showing fast subpicosecond arrival of excitation energy to B850 circular aggregates. Any spectral changes connected with the B800 absorption band of B800-BChl molecules were absent. A similar picture was observed under one-photon excitation of the LH2 complex by 675 nm femtosecond pulses. We believe these effects may be attributed to direct excitation of high-energy excitonic states of a B850 circular aggregate or its vibrational manifold in accordance with the model of Abe [Chem. Phys. 2001, 264, 355-363].

Comparison of B0 versus B0 and B1 field inhomogeneity correction for glycosaminoglycan chemical exchange saturation transfer imaging.

PubMed

Müller-Lutz, Anja; Ljimani, Alexandra; Stabinska, Julia; Zaiss, Moritz; Boos, Johannes; Wittsack, Hans-Jörg; Schleich, Christoph

2018-05-14

The study compares glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging of intervertebral discs corrected for solely B 0 inhomogeneities or both B 0 and B 1 inhomogeneities. Lumbar intervertebral discs of 20 volunteers were examined with T 2 -weighted and gagCEST imaging. Field inhomogeneity correction was performed with B 0 correction only and with correction of both B 0 and B 1 . GagCEST effects measured by the asymmetric magnetization transfer ratio (MTR asym ) and signal-to-noise ratio (SNR) were compared between both methods. Significant higher MTR asym and SNR values were obtained in the nucleus pulposus using B 0 and B 1 correction compared with B 0 -corrected gagCEST. The GagCEST effect was significantly different in the nucleus pulposus compared with the annulus fibrosus for both methods. The B 0 and B 1 field inhomogeneity correction method leads to an improved quality of gagCEST imaging in IVDs compared with only B 0 correction.

Highly sensitive panchromatic ternary polymer photodetectors enabled by Förster resonance energy transfer and post solvent treatment

NASA Astrophysics Data System (ADS)

Wang, Hanyu; Zheng, Yifan; Qin, Ruiheng; Yu, Junsheng

2018-03-01

A panchromatic ternary polymer photodetector (PPD) with broadband response from 300 to 1000 nm is fabricated via incorporating poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-bʹ]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) as the third component in poly(diketopyrrolopyrrole-terthiophene) (PDPP3T) [6]:-phenyl-C71-butyric acid methyl ester (PC71BM), revealing a high detectivity (D *) of 7.02  ×  1011 Jones at 850 nm. Through the analysis of photoluminescence and external quantum efficiency spectroscopy, we find that PTB7 can not only improve the absorption between 500-750 nm to induce more excitons, but also provide non-radiative transfer energy to PDPP3T via Förster resonance energy transfer (FRET). Moreover, we employ post solvent treatment (PST) to rectify the morphology of ternary blends, thus reducing charge recombination, suppressing dark current, and boosting the D * to 1.57  ×  1012 Jones at 850 nm, which is 2.34 folds higher than that of the untreated PPDs. This work indicates that the incorporation of FRET donor and PST in ternary blends is an effective way to develop highly sensitive panchromatic PPDs.

Effects of aggregation on the excitation dynamics of LH2 from Thermochromatium tepidum in aqueous phase and in chromatophores.

PubMed

Yang, Fan; Yu, Long-Jiang; Wang, Peng; Ai, Xi-Cheng; Wang, Zheng-Yu; Zhang, Jian-Ping

2011-06-23

We carried out femtosecond magic-angle and polarized pump-probe spectroscopies for the light-harvesting complex 2 (LH2) from Thermochromatium (Tch.) tepidum in aqueous phase and in chromatophores. To examine the effects of LH2 aggregation on the dynamics of excitation energy transfer, dominant monodispersed and aggregated LH2s were prepared by controlling the surfactant concentrations. The aqueous preparations solubilized with different concentrations of n-dodecyl-β-D-maltoside (DDM) show similar visible-to-near-infrared absorption spectra, but distinctively different aggregation states, as revealed by using dynamic light scattering. The B800 → B850 intra-LH2 energy transfer time was determined to be 1.3 ps for isolated LH2, which, upon aggregation in aqueous phase or clustering in chromatophores, shortened to 1.1 or 0.9 ps, respectively. The light-harvesting complex 1 (LH1) of this thermophilic purple sulfur bacterium contains bacteriochlorophyll a absorbing at 915 nm (B915), and the LH2(B850) → LH1(B915) intercomplex transfer time in chromatophores was found to be 6.6 ps. For chromatophores, a depolarization time of 21 ps was derived from the anisotropy kinetics of B850*, which is attributed to the migration of B850* excitation before being trapped by LH1. In addition, the B850* annihilation is accelerated upon LH2 aggregation in aqueous phase, but it is much less severe upon LH2 clustering in the intracytoplasmic membrane. These results are helpful in understanding the light-harvesting function of a bacterial photosynthetic membrane incorporating different types of antenna complexes.

Triplet-triplet energy transfer from a UV-A absorber butylmethoxydibenzoylmethane to UV-B absorbers.

PubMed

Kikuchi, Azusa; Oguchi-Fujiyama, Nozomi; Miyazawa, Kazuyuki; Yagi, Mikio

2014-01-01

The phosphorescence decay of a UV-A absorber, 4-tert-butyl-4'-methoxydibenzolymethane (BMDBM) has been observed following a 355 nm laser excitation in the absence and presence of UV-B absorbers, 2-ethylhexyl 4-methoxycinnamate (octyl methoxycinnamate, OMC) and octocrylene (OCR) in ethanol at 77 K. The lifetime of the lowest excited triplet (T1) state of BMDBM is significantly reduced in the presence of OMC and OCR. The observed quenching of BMDBM triplet by OMC and OCR suggests that the intermolecular triplet-triplet energy transfer occurs from BMDBM to OMC and OCR. The T1 state of OCR is nonphosphorescent or very weakly phosphorescent. However, we have shown that the energy level of the T1 state of OCR is lower than that of the enol form of BMDBM. Our methodology of energy-donor phosphorescence decay measurements can be applied to the study of the triplet-triplet energy transfer between UV absorbers even if the energy acceptor is nonphosphorescent. In addition, the delayed fluorescence of BMDBM due to triplet-triplet annihilation was observed in the BMDBM-OMC and BMDBM-OCR mixtures in ethanol at 77 K. Delayed fluorescence is one of the deactivation processes of the excited states of BMDBM under our experimental conditions. © 2013 The American Society of Photobiology.

Communication: Broad manifold of excitonic states in light-harvesting complex 1 promotes efficient unidirectional energy transfer in vivo

NASA Astrophysics Data System (ADS)

Sohail, Sara H.; Dahlberg, Peter D.; Allodi, Marco A.; Massey, Sara C.; Ting, Po-Chieh; Martin, Elizabeth C.; Hunter, C. Neil; Engel, Gregory S.

2017-10-01

In photosynthetic organisms, the pigment-protein complexes that comprise the light-harvesting antenna exhibit complex electronic structures and ultrafast dynamics due to the coupling among the chromophores. Here, we present absorptive two-dimensional (2D) electronic spectra from living cultures of the purple bacterium, Rhodobacter sphaeroides, acquired using gradient assisted photon echo spectroscopy. Diagonal slices through the 2D lineshape of the LH1 stimulated emission/ground state bleach feature reveal a resolvable higher energy population within the B875 manifold. The waiting time evolution of diagonal, horizontal, and vertical slices through the 2D lineshape shows a sub-100 fs intra-complex relaxation as this higher energy population red shifts. The absorption (855 nm) of this higher lying sub-population of B875 before it has red shifted optimizes spectral overlap between the LH1 B875 band and the B850 band of LH2. Access to an energetically broad distribution of excitonic states within B875 offers a mechanism for efficient energy transfer from LH2 to LH1 during photosynthesis while limiting back transfer. Two-dimensional lineshapes reveal a rapid decay in the ground-state bleach/stimulated emission of B875. This signal, identified as a decrease in the dipole strength of a strong transition in LH1 on the red side of the B875 band, is assigned to the rapid localization of an initially delocalized exciton state, a dephasing process that frustrates back transfer from LH1 to LH2.

Single-shot ultrabroadband two-dimensional electronic spectroscopy of the light-harvesting complex LH2.

PubMed

Harel, Elad; Long, Phillip D; Engel, Gregory S

2011-05-01

Here we present two-dimensional (2D) electronic spectra of the light-harvesting complex LH2 from purple bacteria using coherent pulses with bandwidth of over 100 nm FWHM. This broadband excitation and detection has allowed the simultaneous capture of both the B800 and B850 bands using a single light source. We demonstrate that one laser pulse is sufficient to capture the entire 2D electronic spectrum with a high signal-to-noise ratio. At a waiting time of 800 fs, we observe population transfer from the B800 to B850 band as manifested by a prominent cross peak. These results will enable observation of the dynamics of biological systems across both ultrafast (<1 ps) and slower (>1 ms) timescales simultaneously.

Energy transfer and colour tunability in UV light induced Tm3+/Tb3+/Eu3+: ZnB glasses generating white light emission.

PubMed

Naresh, V; Gupta, Kiran; Parthasaradhi Reddy, C; Ham, Byoung S

2017-03-15

A promising energy transfer (Tm 3+ →Tb 3+ →Eu 3+ ) approach is brought forward to generate white light emission under ultraviolet (UV) light excitation for solid state lightening. Tm 3+ /Tb 3+ /Eu 3+ ions are combinedly doped in zinc borate glass system in view of understanding energy transfer process resulting in white light emission. Zinc borate (host) glass displayed optical and luminescence properties due to formation of Zn(II) x -[O(-II)] y centres in the ZnB glass matrix. At 360nm (UV) excitation, triply doped Tm 3+ /Tb 3+ /Eu 3+ : ZnB glasses simultaneously shown their characteristic emission bands in blue (454nm: 1 D 2 → 3 F 4 ), green (547nm: 5 D 4 → 7 F 5 ) and red (616nm: 5 D 0 → 7 F 2 ) regions. In triple ions doped glasses, energy transfer dynamics is discussed in terms of Forster-Dexter theory, excitation & emission profiles, lifetime curves and from partial energy level diagram of three ions. The role of Tb 3+ in ET from Tm 3+ →Eu 3+ was discussed using branch model. From emission decay analysis, energy transfer probability (P) and efficiency (η) were evaluated. Colour tunability from blue to white on varying (Tb 3+ , Eu 3+ ) content is demonstrated from Commission Internationale de L'Eclairage (CIE) chromaticity coordinates. Based on chromaticity coordinates, other colour related parameters like correlated colour temperature (CCT) and colour purity are also computed for the studied glass samples. An appropriate blending of such combination of rare earth ions could show better suitability as potential candidates in achieving multi-colour and warm/cold white light emission for white LEDs application in the field of solid state lightening. Copyright © 2016 Elsevier B.V. All rights reserved.

In-situ studies of Fe2B phase formation in MgB2 wires and tapes by means of high-energy x-ray diffraction

NASA Astrophysics Data System (ADS)

Grivel, J. C.; Andersen, N. H.; Pinholt, R.; Ková, P.; Husek, I.; Hässler, W.; Herrmann, M.; Perner, O.; Rodig, C.; Homeyer, J.

2006-06-01

The phase transformations occurring in the ceramic core of Fe-sheathed MgB2 wires and tapes prepared by in-situ reaction of Mg and B precursor powders, have been studied by means of high-energy x-ray diffraction. In particular, the time evolution of the Fe2B phase, forming at the interface between the sheath and the ceramic, was studied at different sintering temperatures. The reactivity of the sheath towards Fe2B formation is strongly dependent on powder pre-treatment. In wires produced with commercial Mg and B powders without additional mechanical activation, the Fe2B phase starts forming around 650°C. In contrast, in tapes produced from a mixture of Mg and B powders subjected to high-energy ball milling, the interfacial Fe2B layer forms readily at 600°C. The increase of Fe2B volume fraction is linear to first approximation, showing that the interfacial layer does not act as a diffusion barrier against further reaction between the sheath and the ceramic core. If the ceramic core is converted to MgB2 at a temperature, which is low enough to avoid Fe2B formation, the interface is stable during further annealing at temperatures up to 700°C at least. However, too high annealing temperatures (T > 800°C), would result in formation of Fe2B, probably following the partial decomposition of MgB2.

Disposal of Energy by UV-B Sunscreens

NASA Astrophysics Data System (ADS)

Nordlund, Thomas; Krishnan, Rajagopal

2008-03-01

Ideal sunscreens absorb dangerous UV light and dispose of the energy safely. ``Safe disposal'' usually means conversion to heat. However, efficient absorption entails a high radiative rate, which implies high energy-transfer and other rates, unless some process intervenes to ``defuse'' the excited state. We studied the excited-state kinetics of three UV-B (290-320 nm) sunscreens by absorption, steady-state and time-resolved fluorescence. Excited-state rate analysis suggests that some sunscreens have low radiative-rate ``dark'' states, in addition to normal excited states.* We deduce dark states when sunscreens of high extinction coefficient do not show lifetimes and total emission consistent with such high radiative rates. A high radiative rate, accompanied by efficient fluorescence emission and/or transfer, may be unfavorable for a sunscreen. In spite of its dark excited state, padimate O shows significant re-emission of light in the UV-A (320-400 nm) and energy transfer to a natural component of excised skin, probably collagen. * Krishnan, R. and T.M. Nordlund (2007) J. Fluoresc. DOI 10.1007/s10895-007-0264-3.

Catalysis of Methyl Group Transfers Involving Tetrahydrofolate and B12

PubMed Central

Ragsdale, Stephen W.

2011-01-01

This review focuses on the reaction mechanism of enzymes that use B12 and tetrahydrofolate (THF) to catalyze methyl group transfers. It also covers the related reactions that use B12 and tetrahydromethanopterin (THMPT), which is a THF analog used by archaea. In the past decade, our understanding of the mechanisms of these enzymes has increased greatly because the crystal structures for three classes of B12-dependent methyltransferases have become available and because biophysical and kinetic studies have elucidated the intermediates involved in catalysis. These steps include binding of the cofactors and substrates, activation of the methyl donors and acceptors, the methyl transfer reaction itself, and product dissociation. Activation of the methyl donor in one class of methyltransferases is achieved by an unexpected proton transfer mechanism. The cobalt (Co) ion within the B12 macrocycle must be in the Co(I) oxidation state to serve as a nucleophile in the methyl transfer reaction. Recent studies have uncovered important principles that control how this highly reducing active state of B12 is generated and maintained. PMID:18804699

A new assay format for NF-kappaB based on a DNA triple helix and a fluorescence resonance energy transfer.

PubMed

Altevogt, Dominik; Hrenn, Andrea; Kern, Claudia; Clima, Lilia; Bannwarth, Willi; Merfort, Irmgard

2009-10-07

Herein we report a feasibility study for a new concept to detect DNA binding protein NF-kappaB based on a DNA triple helix formation in combination with a fluorescence resonance energy transfer (FRET). The new principle avoids expensive antibodies and radioactivity and might have implications for assays of other DNA binding proteins.

Energy transfer mechanism of Sm3+/Eu3+ co-doped 2CaO-B2O3-P2O5 phosphors

NASA Astrophysics Data System (ADS)

Prasad, V. Reddy; Damodaraiah, S.; Ratnakaram, Y. C.

2018-04-01

Sm3+/Eu3+ co-doped calcium borophosphate phosphors were synthesized by solid state reaction method. 2CaO-B2O3-P2O5: Sm3+/Eu3+ co-doped phosphors were characterized by XRD, SEM, 31P solid state NMR, excitation, photoluminescence (PL) and decay profiles.. XRD profiles showed that the prepared phosphors exhibit a hexagonal phase in crystal structure and SEM results showed that the particles are more irregular morphologies. From 31P NMR spectra of Sm3+/Eu3+ co-doped 2CaO-B2O3-P2O5 phosphors, the chemical shifts located in the positive frequency region indicating the presence of mono-phosphate complexes Q0-(PO43 - ) . Photoluminescence spectra of Sm3+/Eu3+ co-doped 2CaO-B2O3-P2O5 phosphors show enhancement in emission intensity of Eu3+ ion due to co-doping with Sm3+ ions through energy transfer process. The energy level mechanism between Sm3+ and Eu3+ ions has been clearly explained. The energy transfer process has also been evidenced by lifetime decay profiles. These results suggest that the prepared phosphors are potential red luminescent optical materials.

O2(b1Σg+, v = 0, 1) Relative Yield in O(1D) + O2 Energy Transfer

NASA Astrophysics Data System (ADS)

Kostko, O.; Raj, S.; Campbell, K. M.; Pejakovic, D. A.; Slanger, T. G.; Kalogerakis, K. S.

2012-04-01

Energy transfer from excited O(1D) atoms to ground-state O2(X3Σg-) leads to production of O2 in the first two vibrational levels of the O2(b1Σg+) state: O(1D) + O2 → O(3P ) + O2(b1Σg+, v = 0, 1). Subsequent radiative decay of O2(b1Σg+, v = 0, 1) to the ground state results in the Atmospheric Band emission, a prominent feature of the terrestrial airglow. The relative yield for production of O2(b1Σg+, v = 0, 1) in the above process, k1/k0, is an important parameter in modeling of the observed O2 Atmospheric Band emission intensities. In the laboratory experiments, the output of a pulsed fluorine laser at 157 nm is used to photodissociate molecular oxygen in an O2/N2 mixture flowing through a heated gas cell. Photodissociation of O2 produces a ground-state O(3P ) atom and an excited O(1D) atom. O(1D) rapidly transfers energy to the remaining O2 to produce O2(b1Σg+, v = 0, 1). The populations of O2(b1Σg+, v = 0, 1) are monitored by observing emissions in the O2(b-X) 0-0 and 1-0 bands at 762 and 688 nm, respectively. The value of k1/k0 is extracted from the time-dependent O2(b1Σg+, v = 0, 1) fluorescence signals using computer simulations. We find that production of v = 1 is substantially larger than that of v = 0. We will present measurements on k1/k0 and its temperature dependence, and discuss the significance of these and other relevant laboratory measurements on the interpretation of the O2 Atmospheric Band emission. This work was supported by the US National Science Foundation (NSF) Aeronomy Program under grant AGS-0937317. The fluorine laser was purchased under grant ATM-0216583 from the NSF Major Research Instrumentation Program. The participation of Sumana Raj and Kendrick M. Campbell was supported by a Research Experiences for Undergraduates (REU) site, co-funded by the Division of Physics of the NSF and the Department of Defense in partnership with the NSF REU program (PHY-1002892).

Energy transfers in large-scale and small-scale dynamos

NASA Astrophysics Data System (ADS)

Samtaney, Ravi; Kumar, Rohit; Verma, Mahendra

2015-11-01

We present the energy transfers, mainly energy fluxes and shell-to-shell energy transfers in small-scale dynamo (SSD) and large-scale dynamo (LSD) using numerical simulations of MHD turbulence for Pm = 20 (SSD) and for Pm = 0.2 on 10243 grid. For SSD, we demonstrate that the magnetic energy growth is caused by nonlocal energy transfers from the large-scale or forcing-scale velocity field to small-scale magnetic field. The peak of these energy transfers move towards lower wavenumbers as dynamo evolves, which is the reason for the growth of the magnetic fields at the large scales. The energy transfers U2U (velocity to velocity) and B2B (magnetic to magnetic) are forward and local. For LSD, we show that the magnetic energy growth takes place via energy transfers from large-scale velocity field to large-scale magnetic field. We observe forward U2U and B2B energy flux, similar to SSD.

Energy transfer between surface-immobilized light-harvesting chlorophyll a/b complex (LHCII) studied by surface plasmon field-enhanced fluorescence spectroscopy (SPFS).

PubMed

Lauterbach, Rolf; Liu, Jing; Knoll, Wolfgang; Paulsen, Harald

2010-11-16

The major light-harvesting chlorophyll a/b complex (LHCII) of the photosynthetic apparatus in green plants can be viewed as a protein scaffold binding and positioning a large number of pigment molecules that combines rapid and efficient excitation energy transfer with effective protection of its pigments from photobleaching. These properties make LHCII potentially interesting as a light harvester (or a model thereof) in photoelectronic applications. Most of such applications would require the LHCII to be immobilized on a solid surface. In a previous study we showed the immobilization of recombinant LHCII on functionalized gold surfaces via a 6-histidine tag (His tag) in the protein moiety. In this work the occurrence and efficiency of Förster energy transfer between immobilized LHCII on a functionalized surface have been analyzed by surface plasmon field-enhanced fluorescence spectroscopy (SPFS). A near-infrared dye was attached to some but not all of the LHC complexes, serving as an energy acceptor to chlorophylls. Analysis of the energy transfer from chlorophylls to this acceptor dye yielded information about the extent of intercomplex energy transfer between immobilized LHCII.

Novel Nd 2WO 6-type Sm 2- xA xM 1- yB yO 6- δ (A = Ca, Sr; M = Mo, W; B = Ce, Ni) mixed conductors

NASA Astrophysics Data System (ADS)

Li, Qin; Thangadurai, Venkataraman

In the present work, we have explored novel Nd 2WO 6-type structure Sm 2- xA xM 1- yB yO 6- δ (A = Ca, Sr; M = Mo, W; B = Ce, Ni) as precursor for the development of solid oxide fuel cells (SOFCs) anodes. The formation of single-phase monoclinic structure was confirmed by powder X-ray diffraction (PXRD) for the A- and B-doped Sm 2MO 6 (SMO). Samples after AC measurements under wet H 2 up to 850 °C changed from Nd 2WO 6-type structure into Sm 2MoO 5 due to the reduction of Mo VI that was confirmed by PXRD and is consistent with literature. The electrical conductivity was determined using 2-probe AC impedance and DC method and was compared with 4-probe DC method. The total electrical conductivity obtained from these two different techniques was found to vary within the experimental error over the investigated temperature of 350-650 °C. Ionic and electronic conductivity were studied using electron-blocking electrodes technique. Among the samples studied, Sm 1.8Ca 0.2MoO 6- δ exhibits total conductivity of 0.12 S cm -1 at 550 °C in wet H 2 with an activation energy of 0.06 eV. Ca-doped SMO appears to be chemically stable against reaction with YSZ electrolyte at 800 °C for 24 h in wet H 2. The ionic transference number (t i) of Sm 1.9Ca 0.1MoO 6- δ in wet H 2 at 550 °C (pO 2 = 10 -25.5 atm) was found to be about 0.012 after subtraction of electrical lead resistance from the 2-probe AC data and showed predominate electronic conductors.

Energy transfer from Pr3+ to Gd3+ ions in BaB8O13 phosphor for phototherapy lamps

NASA Astrophysics Data System (ADS)

Tamboli, Sumedha; Nair, Govind B.; Dhoble, S. J.; Burghate, D. K.

2018-04-01

A series of BaB8O13 phosphors doped with different concentrations of Gd3+ ions and co-doped with Pr3+ ions were synthesized by solid state synthesis method. X-ray powder diffraction (XRD) analysis confirmed the formation of the compound in a crystalline and homogeneous form. Scanning Electron Microscopy (SEM) was performed to study the surface morphology of the compound and Fourier Transform Infrared (FT-IR) spectroscopy measurements determined the nature of bonding between elements of the compounds. The photoluminescence (PL) excitation spectra of BaB8O13:Gd3+ phosphor showed excitation peaks at 246 nm, 252 nm and 274 nm. The prominent emission peak was observed at 313 nm which is in narrow band ultraviolet B (NB-UVB) range. Energy transfer was achieved by co-doping Pr3+ ions with Gd3+ ions. PL decay time was also measured for BaB8O13: Gd3+, Pr3+ phosphor. Emission at 313 nm can be used for the treatment of skin diseases.

Lipid transfer proteins in the assembly of apoB-containing lipoproteins.

PubMed

Sirwi, Alaa; Hussain, M Mahmood

2018-04-12

A better understanding of intracellular lipoprotein assembly may help identify proteins with important roles in lipid disorders. ApoB-containing lipoproteins are macromolecular lipid and protein micelles that act as specialized transport vehicles for hydrophobic lipids. They are assembled predominantly in enterocytes and hepatocytes to transport dietary and endogenous fat, respectively, to different tissues. Assembly occurs in the endoplasmic reticulum and is dependent on lipid re-synthesis in the endoplasmic reticulum and on a chaperone, namely microsomal triglyceride transfer protein. Precursors for lipid synthesis are obtained from extracellular sources and from cytoplasmic lipid droplets. Microsomal triglyceride transfer protein is the major and essential lipid transfer protein that transfers phospholipids and triacylglycerols to nascent apoB for the assembly of lipoproteins. Assembly is aided by cell death-inducing DFF45-like effector B and by phospholipid transfer protein, which may facilitate additional deposition of triacylglycerols and phospholipids, respectively, to apoB. Here, we summarize the current understanding of the different steps in the assembly of apoB-containing lipoproteins and discuss the role of lipid transfer proteins in these steps to help identify new clinical targets for lipid-associated disorders, such as heart disease. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Efficient near-field wireless energy transfer using adiabatic system variations

DOEpatents

Hamam, Rafif E.; Karalis, Aristeidis; Joannopoulos, John D.; Soljacic, Marin

2013-01-29

Disclosed is a method for transferring energy wirelessly including transferring energy wirelessly from a first resonator structure to an intermediate resonator structure, wherein the coupling rate between the first resonator structure and the intermediate resonator structure is .kappa..sub.1B, transferring energy wirelessly from the intermediate resonator structure to a second resonator structure, wherein the coupling rate between the intermediate resonator structure and the second resonator structure is .kappa..sub.B2, and during the wireless energy transfers, adjusting at least one of the coupling rates .kappa..sub.1B and .kappa..sub.B2 to reduce energy accumulation in the intermediate resonator structure and improve wireless energy transfer from the first resonator structure to the second resonator structure through the intermediate resonator structure.

Efficient near-field wireless energy transfer using adiabatic system variations

DOEpatents

Hamam, Rafif E; Karalis, Aristeidis; Joannopoulos, John D; Soljacic, Marin

2014-09-16

Disclosed is a method for transferring energy wirelessly including transferring energy wirelessly from a first resonator structure to an intermediate resonator structure, wherein the coupling rate between the first resonator structure and the intermediate resonator structure is .kappa..sub.1B, transferring energy wirelessly from the intermediate resonator structure to a second resonator structure, wherein the coupling rate between the intermediate resonator structure and the second resonator structure is .kappa..sub.B2, and during the wireless energy transfers, adjusting at least one of the coupling rates .kappa..sub.1B and .kappa..sub.B2 to reduce energy accumulation in the intermediate resonator structure and improve wireless energy transfer from the first resonator structure to the second resonator structure through the intermediate resonator structure.

Excitonic energy transfer in light-harvesting complexes in purple bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye Jun; Sun Kewei; Zhao Yang

Two distinct approaches, the Frenkel-Dirac time-dependent variation and the Haken-Strobl model, are adopted to study energy transfer dynamics in single-ring and double-ring light-harvesting (LH) systems in purple bacteria. It is found that the inclusion of long-range dipolar interactions in the two methods results in significant increase in intra- or inter-ring exciton transfer efficiency. The dependence of exciton transfer efficiency on trapping positions on single rings of LH2 (B850) and LH1 is similar to that in toy models with nearest-neighbor coupling only. However, owing to the symmetry breaking caused by the dimerization of BChls and dipolar couplings, such dependence has beenmore » largely suppressed. In the studies of coupled-ring systems, both methods reveal an interesting role of dipolar interactions in increasing energy transfer efficiency by introducing multiple intra/inter-ring transfer paths. Importantly, the time scale (4 ps) of inter-ring exciton transfer obtained from polaron dynamics is in good agreement with previous studies. In a double-ring LH2 system, non-nearest neighbor interactions can induce symmetry breaking, which leads to global and local minima of the average trapping time in the presence of a non-zero dephasing rate, suggesting that environment dephasing helps preserve quantum coherent energy transfer when the perfect circular symmetry in the hypothetic system is broken. This study reveals that dipolar coupling between chromophores may play an important role in the high energy transfer efficiency in the LH systems of purple bacteria and many other natural photosynthetic systems.« less

Efficient near-field wireless energy transfer using adiabatic system variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamam, Rafif E.; Karalis, Aristeidis; Joannopoulos, John D.

Disclosed is a method for transferring energy wirelessly including transferring energy wirelessly from a first resonator structure to an intermediate resonator structure, wherein the coupling rate between the first resonator structure and the intermediate resonator structure is .kappa..sub.1B, transferring energy wirelessly from the intermediate resonator structure to a second resonator structure, wherein the coupling rate between the intermediate resonator structure and the second resonator structure is .kappa..sub.B2, and during the wireless energy transfers, adjusting at least one of the coupling rates .kappa..sub.1B and .kappa..sub.B2 to reduce energy accumulation in the intermediate resonator structure and improve wireless energy transfer from themore » first resonator structure to the second resonator structure through the intermediate resonator structure.« less

Ab initio study of charge transfer in B2+ low-energy collisions with atomic hydrogen

NASA Astrophysics Data System (ADS)

Turner, A. R.; Cooper, D. L.; Wang, J. G.; Stancil, P. C.

2003-07-01

Charge transfer processes due to collisions of ground state B2+(2s 2S) ions with atomic hydrogen are investigated using the quantum-mechanical molecular-orbital close-coupling (MOCC) method. The MOCC calculations utilize ab initio adiabatic potentials and nonadiabatic radial and rotational coupling matrix elements obtained with the spin-coupled valence-bond approach. Total and state-selective cross sections and rate coefficients are presented. Comparison with the existing experiments shows our results to be in good agreement. When E<80 eV/u, the differences between the current total MOCC cross sections with and without rotational coupling are small (<3%). Rotational coupling becomes more important with increasing energy: for collision energies E>400 eV/u, inclusion of rotational coupling increases the total cross section by 50% 80%, improving the agreement between the current calculations and experiments. For state-selective cross sections, rotational coupling induces mixing between different symmetries; however, its effect, especially at low collision energies, is not as important as had been suggested in previous work.

Vapor annealing synthesis of non-epitaxial MgB2 films on glassy carbon

NASA Astrophysics Data System (ADS)

Baker, A. A.; Bayu Aji, L. B.; Bae, J. H.; Stavrou, E.; Steich, D. J.; McCall, S. K.; Kucheyev, S. O.

2018-05-01

We describe the fabrication and characterization of 25–800 nm thick MgB2 films on glassy carbon substrates by Mg vapor annealing of sputter-deposited amorphous B films. Results demonstrate a critical role of both the initial B film thickness and the temperature–time profile on the microstructure, elemental composition, and superconducting properties of the resultant MgB2 films. Films with thicknesses of 55 nm and below exhibit a smooth surface, with a roughness of 1.1 nm, while thicker films have surface morphology consisting of elongated nano-crystallites. The suppression of the superconducting transition temperature for thin films scales linearly with the oxygen impurity concentration and also correlates with the amount of lattice disorder probed by Raman scattering. The best results are obtained by a rapid (12 min) anneal at 850 °C with large temperature ramp and cooling rates of ∼540 °C min‑1. Such fast processing suppresses the deleterious oxygen uptake.

Elasticity of superhydrous phase B at the mantle temperature and pressure: Implications for 800-km discontinuity and water flow into lower mantle

NASA Astrophysics Data System (ADS)

Yang, D.; Wang, W.; Wu, Z.

2017-12-01

Plate subduction can transport the water to the Earth's interior by forming hydrous phases and water can exert important effects on global dynamics and many processes within the deep Earth. Superhydrous phase B (ShyB), as an important candidate for transporting water into the mantle transition zone and lower mantle, is stable up to 31 GPa and will decompose into bridgmanite, periclase and water at a depth of 800 km [Komabayashi and Omori, 2006]. The decomposition of ShyB may be related to the seismic discontinuity at the depth of 800 km in Western-Pacific Subduction Zones [Liu et al., 2016; Porritt and Yoshioka, 2016]. The detail discussions on this topic require the elasticity of ShyB at the P-T conditions of the transition zone and lower mantle. In this contribution, we obtained the thermal elasticity of ShyB using first-principles calculations. ShyB shows a very low velocity and density compared to the bridgmanite and periclase, the major minerals in the lower mantle. The accumulation of ShyB will generate the low-velocity anomaly in the uppermost lower mantle. The dehydration of ShyB will cause the Vp, Vs, and density increase by 7.5%, 15.0% and 12%, respectively. It means that a slab with 10% ShyB could cause an impedance contrast of 2.7% at a depth of 800 km for shear wave. Furthermore, the released waters by the dehydration of ShyB probably migrate upward and promote the partial melt to reduce the sound velocity at shallower depth, which can further explain the low-velocity zones just above 800-km discontinuity in Western-Pacific Subduction Zones [Liu et al., 2016]. Komabayashi, T., and S. Omori (2006), Internally consistent thermodynamic data set for dense hydrous magnesium silicates up to 35GPa, 1600°C: Implications for water circulation in the Earth's deep mantle, Physics of the Earth and Planetary Interiors, 156(1-2), 89-107. Liu, Z., J. Park, and S. I. Karato (2016), Seismological detection of low-velocity anomalies surrounding the mantle transition

Energy transfer and colour tunability in UV light induced Tm3 +/Tb3 +/Eu3 +: ZnB glasses generating white light emission

NASA Astrophysics Data System (ADS)

Naresh, V.; Gupta, Kiran; Parthasaradhi Reddy, C.; Ham, Byoung S.

2017-03-01

A promising energy transfer (Tm3 + → Tb3 + → Eu3 +) approach is brought forward to generate white light emission under ultraviolet (UV) light excitation for solid state lightening. Tm3 +/Tb3 +/Eu3 + ions are combinedly doped in zinc borate glass system in view of understanding energy transfer process resulting in white light emission. Zinc borate (host) glass displayed optical and luminescence properties due to formation of Zn(II)x-[O(- II)]y centres in the ZnB glass matrix. At 360 nm (UV) excitation, triply doped Tm3 +/Tb3 +/Eu3 +: ZnB glasses simultaneously shown their characteristic emission bands in blue (454 nm: 1D2 → 3F4), green (547 nm: 5D4 → 7F5) and red (616 nm: 5D0 → 7F2) regions. In triple ions doped glasses, energy transfer dynamics is discussed in terms of Forster-Dexter theory, excitation & emission profiles, lifetime curves and from partial energy level diagram of three ions. The role of Tb3 + in ET from Tm3 + → Eu3 + was discussed using branch model. From emission decay analysis, energy transfer probability (P) and efficiency (η) were evaluated. Colour tunability from blue to white on varying (Tb3 +, Eu3 +) content is demonstrated from Commission Internationale de L'Eclairage (CIE) chromaticity coordinates. Based on chromaticity coordinates, other colour related parameters like correlated colour temperature (CCT) and colour purity are also computed for the studied glass samples. An appropriate blending of such combination of rare earth ions could show better suitability as potential candidates in achieving multi-colour and warm/cold white light emission for white LEDs application in the field of solid state lightening.

Static and dynamic protein impact on electronic properties of light-harvesting complex LH2.

PubMed

Zerlauskiene, O; Trinkunas, G; Gall, A; Robert, B; Urboniene, V; Valkunas, L

2008-12-11

A comparative analysis of the temperature dependence of the absorption spectra of the LH2 complexes from different species of photosynthetic bacteria, i.e., Rhodobacter sphaeroides, Rhodoblastus acidophilus, and Phaeospirillum molischianum, was performed in the temperature range from 4 to 300 K. Qualitatively, the temperature dependence is similar for all of the species studied. The spectral bandwidths of both B800 and B850 bands increases with temperature while the band positions shift in opposite directions: the B800 band shifts slightly to the red while the B850 band to the blue. These results were analyzed using the modified Redfield theory based on the exciton model. The main conclusion drawn from the analysis was that the spectral density function (SDF) is the main factor underlying the strength of the temperature dependence of the bandwidths for the B800 and B850 electronic transitions, while the bandwidths themselves are defined by the corresponding inhomogeneous distribution function (IDF). Slight variation of the slope of the temperature dependence of the bandwidths between species can be attributed to the changes of the values of the reorganization energies and characteristic frequencies determining the SDF. To explain the shift of the B850 band position with temperature, which is unusual for the conventional exciton model, a temperature dependence of the IDF must be postulated. This dependence can be achieved within the framework of the modified (dichotomous) exciton model. The slope of the temperature dependence of the B850 bandwidth is then defined by the value of the reorganization energy and by the difference between the transition energies of the dichotomous states of the pigment molecules. The equilibration factor between these dichotomous states mainly determines the temperature dependence of the peak shift.

Energy-dependent motion of TonB in the Gram-negative bacterial inner membrane

PubMed Central

Jordan, Lorne D.; Zhou, Yongyao; Smallwood, Chuck R.; Lill, Yoriko; Ritchie, Ken; Yip, Wai Tak; Newton, Salete M.; Klebba, Phillip E.

2013-01-01

Gram-negative bacteria acquire iron with TonB-dependent uptake systems. The TonB–ExbBD inner membrane complex is hypothesized to transfer energy to outer membrane (OM) iron transporters. Fluorescence microscopic characterization of green fluorescent protein (GFP)-TonB hybrid proteins revealed an unexpected, restricted localization of TonB in the cell envelope. Fluorescence polarization measurements demonstrated motion of TonB in living cells, which likely was rotation. By determining the anisotropy of GFP-TonB in the absence and presence of inhibitors, we saw the dependence of its motion on electrochemical force and on the actions of ExbBD. We observed higher anisotropy for GFP-TonB in energy-depleted cells and lower values in bacteria lacking ExbBD. However, the metabolic inhibitors did not change the anisotropy of GFP-TonB in ΔexbBD cells. These findings demonstrate that TonB undergoes energized motion in the bacterial cell envelope and that ExbBD couples this activity to the electrochemical gradient. The results portray TonB as an energized entity in a regular array underlying the OM bilayer, which promotes metal uptake through OM transporters by a rotational mechanism. PMID:23798405

Atomistic non-adiabatic dynamics of the LH2 complex with a GPU-accelerated ab initio exciton model

DOE PAGES

Sisto, Aaron; Stross, Clem; van der Kamp, Marc W.; ...

2017-03-28

We recently outlined an efficient multi-tiered parallel ab initio excitonic framework that utilizes time dependent density functional theory (TDDFT) to calculate ground and excited state energies and gradients of large supramolecular complexes in atomistic detail – enabling us to undertake non-adiabatic simulations which explicitly account for the coupled anharmonic vibrational motion of all the constituent atoms in a supramolecular system. Here we apply that framework to the 27 coupled bacterio-chlorophyll-a chromophores which make up the LH2 complex, using it to compute an on-the-fly nonadiabatic surface-hopping (SH) trajectory of electronically excited LH2. Part one of this article is focussed on calibratingmore » our ab initio exciton Hamiltonian using two key parameters: a shift δ, which corrects for the error in TDDFT vertical excitation energies; and an effective dielectric constant ε, which describes the average screening of the transition-dipole coupling between chromophores. Using snapshots obtained from equilibrium molecular dynamics simulations (MD) of LH2, we tune the values of both δ and ε through fitting to the thermally broadened experimental absorption spectrum, giving a linear absorption spectrum that agrees reasonably well with experiment. In part two of this article, we construct a time-resolved picture of the coupled vibrational and excitation energy transfer (EET) dynamics in the sub-picosecond regime following photo-excitation. Assuming Franck–Condon excitation of a narrow eigenstate band centred at 800 nm, we use surface hopping to follow a single nonadiabatic dynamics trajectory within the full eigenstate manifold. Consistent with experimental data, this trajectory gives timescales for B800→B850 population transfer (τ B800→B850) between 650–1050 fs, and B800 population decay (τ 800→) between 10–50 fs. The dynamical picture that emerges is one of rapidly fluctuating LH2 eigenstates that are delocalized over multiple

Atomistic non-adiabatic dynamics of the LH2 complex with a GPU-accelerated ab initio exciton model.

PubMed

Sisto, Aaron; Stross, Clem; van der Kamp, Marc W; O'Connor, Michael; McIntosh-Smith, Simon; Johnson, Graham T; Hohenstein, Edward G; Manby, Fred R; Glowacki, David R; Martinez, Todd J

2017-06-14

We recently outlined an efficient multi-tiered parallel ab initio excitonic framework that utilizes time dependent density functional theory (TDDFT) to calculate ground and excited state energies and gradients of large supramolecular complexes in atomistic detail - enabling us to undertake non-adiabatic simulations which explicitly account for the coupled anharmonic vibrational motion of all the constituent atoms in a supramolecular system. Here we apply that framework to the 27 coupled bacterio-chlorophyll-a chromophores which make up the LH2 complex, using it to compute an on-the-fly nonadiabatic surface-hopping (SH) trajectory of electronically excited LH2. Part one of this article is focussed on calibrating our ab initio exciton Hamiltonian using two key parameters: a shift δ, which corrects for the error in TDDFT vertical excitation energies; and an effective dielectric constant ε, which describes the average screening of the transition-dipole coupling between chromophores. Using snapshots obtained from equilibrium molecular dynamics simulations (MD) of LH2, we tune the values of both δ and ε through fitting to the thermally broadened experimental absorption spectrum, giving a linear absorption spectrum that agrees reasonably well with experiment. In part two of this article, we construct a time-resolved picture of the coupled vibrational and excitation energy transfer (EET) dynamics in the sub-picosecond regime following photo-excitation. Assuming Franck-Condon excitation of a narrow eigenstate band centred at 800 nm, we use surface hopping to follow a single nonadiabatic dynamics trajectory within the full eigenstate manifold. Consistent with experimental data, this trajectory gives timescales for B800→B850 population transfer (τ B800→B850 ) between 650-1050 fs, and B800 population decay (τ 800→ ) between 10-50 fs. The dynamical picture that emerges is one of rapidly fluctuating LH2 eigenstates that are delocalized over multiple chromophores and

Characterization of horizontally transferred β-fructofuranosidase (ScrB) genes in Agrilus planipennis.

PubMed

Zhao, C; Doucet, D; Mittapalli, O

2014-12-01

The emerald ash borer (Agrilus planipennis) is an important invasive insect pest of Fraxinus spp. that feeds on host tissues containing high levels of sucrose. However, little is known about how it digests sucrose. Here, using larval midgut transcriptome data and preliminary genome sequence efforts, two β-fructofuranosidase-encoding ScrB genes, AplaScrB-1 and AplaScrB-2, were identified, and proved to reside within the A. planipennis genome. Homology and phylogenetic analysis revealed that they were acquired by A. planipennis via horizontal gene transfer (HGT) from bacteria, possibly an event independent from that reported in bark beetles (eg ScrB genes). Microsynteny between A. planipennis DNA scaffold #2042940, which hosts AplaScrB-1, and a region in the Tribolium castaneum chromosome LG4 suggested that A. planipennis gained this gene after the separation of Buprestidae and Tenebrionidae. Although both of the putative AplaScrB proteins have conserved β-fructofuranosidase motifs, only AplaScrB-2 was predicted to be a secretory protein. Expression of AplaScrB-1 seemed constitutive during development and in all tissues examined, whereas AplaScrB-2 showed a peak expression in adults and in the midgut. We propose that acquisition of these genes by A. planipennis from bacteria is adaptive, and specifically AplaScrB-2 is involved in breaking down dietary sucrose to obtain energy for development. © 2014 The Royal Entomological Society.

Tuning of Hemes b Equilibrium Redox Potential Is Not Required for Cross-Membrane Electron Transfer.

PubMed

Pintscher, Sebastian; Kuleta, Patryk; Cieluch, Ewelina; Borek, Arkadiusz; Sarewicz, Marcin; Osyczka, Artur

2016-03-25

In biological energy conversion, cross-membrane electron transfer often involves an assembly of two hemesb The hemes display a large difference in redox midpoint potentials (ΔEm_b), which in several proteins is assumed to facilitate cross-membrane electron transfer and overcome a barrier of membrane potential. Here we challenge this assumption reporting on hemebligand mutants of cytochromebc1in which, for the first time in transmembrane cytochrome, one natural histidine has been replaced by lysine without loss of the native low spin type of heme iron. With these mutants we show that ΔEm_b can be markedly increased, and the redox potential of one of the hemes can stay above the level of quinone pool, or ΔEm_b can be markedly decreased to the point that two hemes are almost isopotential, yet the enzyme retains catalytically competent electron transfer between quinone binding sites and remains functionalin vivo This reveals that cytochromebc1can accommodate large changes in ΔEm_b without hampering catalysis, as long as these changes do not impose overly endergonic steps on downhill electron transfer from substrate to product. We propose that hemesbin this cytochrome and in other membranous cytochromesbact as electronic connectors for the catalytic sites with no fine tuning in ΔEm_b required for efficient cross-membrane electron transfer. We link this concept with a natural flexibility in occurrence of several thermodynamic configurations of the direction of electron flow and the direction of the gradient of potential in relation to the vector of the electric membrane potential. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Agrobacterium VirB10, an ATP energy sensor required for type IV secretion.

PubMed

Cascales, Eric; Christie, Peter J

2004-12-07

Bacteria use type IV secretion systems (T4SS) to translocate DNA and protein substrates to target cells of phylogenetically diverse taxa. Recently, by use of an assay termed transfer DNA immunoprecipitation (TrIP), we described the translocation route for a DNA substrate [T-DNA, portion of the Ti (tumor-inducing) plasmid that is transferred to plant cells] of the Agrobacterium tumefaciens VirB/D4 T4SS in terms of a series of temporally and spatially ordered substrate contacts with subunits of the secretion channel. Here, we report that the bitopic inner membrane protein VirB10 undergoes a structural transition in response to ATP utilization by the VirD4 and VirB11 ATP-binding subunits, as monitored by protease susceptibility. VirB10 interacts with inner membrane VirD4 independently of cellular energetic status, whereas the energy-induced conformational change is required for VirB10 complex formation with an outer membrane-associated heterodimer of VirB7 lipoprotein and VirB9, as shown by coimmunoprecipitation. Under these conditions, the T-DNA substrate is delivered from the inner membrane channel components VirB6 and VirB8 to periplasmic and outer membrane-associated VirB2 pilin and VirB9. We propose that VirD4 and VirB11 coordinate the ATP-dependent formation of a VirB10 "bridge" between inner and outer membrane subassemblies of the VirB/D4 T4SS, and that this morphogenetic event is required for T-DNA translocation across the A. tumefaciens cell envelope.

Space shuttle: Heat transfer rate measurements on Convair booster (B-15B-2) at nominal Mach number of 8

NASA Technical Reports Server (NTRS)

Warmbrod, J. D.; Martindale, W. R.; Matthews, R. K.

1971-01-01

Plotted and tabulated data on heat transfer from a thin-skin thermocouple are presented. The data is representative of the reentry event of the booster alone configuration. The data were generated during wind tunnel tests of the B-15B-2 delta wing booster at Mach 8. Thermocouple measurements are reduced to heat transfer coefficient ratio and the data are presented as plotted variations versus longitudinal, lateral, and vertical local model positions.

High Temperature Gas Energy Transfer.

DTIC Science & Technology

1982-08-15

will be made. A theoretical model has been applied to the calculation of energy transfer amounts between molecules as a function of molecular size... theoretical analysis was given of shock tube data for high temperature gas reactions. The data were analyzed to show that colli- sional energy transfer...Systems by I. Oref and B. S. Rabiovitch. In this report a simple theoretical model describing energy transfer probabilities is given. Conservation of

A hypothetical complex between crystalline flavocytochrome b2 and cytochrome c.

PubMed

Tegoni, M; White, S A; Roussel, A; Mathews, F S; Cambillau, C

1993-08-01

Flavocytochrome b2 and cytochrome c are physiological electron transfer partners in yeast mitochondria. The formation of a stable complex between them has been demonstrated both in solution and in the crystalline state. On the basis of the three-dimensional structures, using molecular modeling and energy minimization, we have generated a hypothetical model for the interaction of these redox partners in the crystal lattice. General criteria such as good charge and surface complementarity, plausible orientation, and separation distance of the prosthetic groups, as well as more specific criteria such as the stoichiometry determined in the crystal, and the involvement of both domains and of more than one subunit of flavocytochrome b2 led us to discriminate between several possible interaction sites. In the hypothetical model we present, four cytochrome c molecules interact with a tetramer of flavocytochrome b2. The b2 and c hemes are coplanar, with an edge-to-edge distance of 14 A. The contact surface area is ca. 800 A2. Several electrostatic interactions involving the flavin and the heme domains of flavocytochrome b2 stabilize the binding of cytochrome c.

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Uniform Test Method for Measuring the Energy Consumption... ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. B Appendix B to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Freezers The provisions...

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Uniform Test Method for Measuring the Energy Consumption... ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. B Appendix B to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Freezers The provisions...

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Freezers

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Uniform Test Method for Measuring the Energy Consumption... ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. B Appendix B to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Freezers The provisions...

10 CFR 850.25 - Exposure reduction and minimization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... § 850.25 Exposure reduction and minimization. (a) The responsible employer must ensure that no worker is exposed above the exposure limit prescribed in § 850.22. (b) The responsible employer must, in addition... described in the responsible employer's CBDPP and must include: (i) Annual goals for exposure reduction and...

Spectral diffusion and electron-phonon coupling of the B800 BChl a molecules in LH2 complexes from three different species of purple bacteria.

PubMed

Baier, J; Gabrielsen, M; Oellerich, S; Michel, H; van Heel, M; Cogdell, R J; Köhler, J

2009-11-04

We have investigated the spectral diffusion and the electron-phonon coupling of B800 bacteriochlorophyll a molecules in the peripheral light-harvesting complex LH2 for three different species of purple bacteria, Rhodobacter sphaeroides, Rhodospirillum molischianum, and Rhodopseudomonas acidophila. We come to the conclusion that B800 binding pockets for Rhodobacter sphaeroides and Rhodopseudomonas acidophila are rather similar with respect to the polarity of the protein environment but that the packaging of the alphabeta-polypeptides seems to be less tight in Rb. sphaeroides with respect to the other two species.

High-power Femtosecond Optical Parametric Amplification at 1 kHz in BiB(3)O(6) pumped at 800 nm.

PubMed

Petrov, Valentin; Noack, Frank; Tzankov, Pancho; Ghotbi, Masood; Ebrahim-Zadeh, Majid; Nikolov, Ivailo; Buchvarov, Ivan

2007-01-22

Substantial power scaling of a travelling-wave femtosecond optical parametric amplifier, pumped near 800 nm by a 1 kHz Ti:sapphire laser amplifier, is demonstrated using monoclinic BiB(3)O(6) in a two stage scheme with continuum seeding. Total energy output (signal plus idler) exceeding 1 mJ is achieved, corresponding to an intrinsic conversion efficiency of approximately 32% for the second stage. The tunability extends from 1.1 to 2.9 microm. The high parametric gain and broad amplification bandwidth of this crystal allowed the maintenance of the pump pulse duration, leading to pulse lengths less than 140 fs, both for the signal and idler pulses, even at such high output levels.

30 CFR 800.10 - Information collection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Information collection. 800.10 Section 800.10... REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.10 Information collection. The collection of information contained in §§ 800.11, 800.21(c), 800.23(b)(2), 800.23(b)(3), 800...

30 CFR 800.10 - Information collection.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Information collection. 800.10 Section 800.10... REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.10 Information collection. The collection of information contained in §§ 800.11, 800.21(c), 800.23(b)(2), 800.23(b)(3), 800...

Cloning, enhanced expression and characterization of an α-amylase gene from a wild strain in B. subtilis WB800.

PubMed

Chen, Jing; Chen, Xianghua; Dai, Jun; Xie, Guangrong; Yan, Luying; Lu, Lina; Chen, Jianhua

2015-09-01

A Bacillus strain with high productivity of α-amylase isolated from a starch farm was identified as Bacillus amyloliquefaciens. The α-amylase encoding gene amy1 was cloned into pMD18-T vector and amplified in E. coli DH5α. Shuttle vector pP43MNX was reconstructed to obtain vector pP43X for heterologous expression of the α-amylase in B. subtilis WB800. Recombinant enzyme was sufficiently purified by precipitation, gel filtration and anion exchange with a specific activity of 5566 U/mg. The α-amylase sequence contains an open reading frame of 1545 bp, which encodes a protein of 514 amino acid residues with a predicted molecular mass of 58.4 kDa. The enzyme exhibited maximal activity at pH 6.0 and 60 °C. Catalytic efficiency of the recombinant α-amylase was inhibited by Hg(2+), Pb(2+) and Cu(2+), but stimulated by Li(+), Mn(2+) and Ca(2+). The purified enzyme showed decreased activity toward detergents (SDS, Tween 20 and Triton X-100). Compared with production by the wild strain, there was a 1.48-fold increase in the productivity of α-amylase in recombinant B. subtilis WB800. Copyright © 2015 Elsevier B.V. All rights reserved.

Forster energy transfer in chlorosomes of green photosynthetic bacteria

NASA Technical Reports Server (NTRS)

Causgrove, T. P.; Brune, D. C.; Blankenship, R. E.

1992-01-01

Energy transfer properties of whole cells and chlorosome antenna complexes isolated from the green sulfur bacteria Chlorobium limicola (containing bacteriochlorophyll c), Chlorobium vibrioforme (containing bacteriochlorophyll d) and Pelodictyon phaeoclathratiforme (containing bacteriochlorophyll e) were measured. The spectral overlap of the major chlorosome pigment (bacteriochlorophyll c, d or, e) with the bacteriochlorophyll a B795 chlorosome baseplate pigment is greatest for bacteriochlorophyll c and smallest for bacteriochlorophyll e. The absorbance and fluorescence spectra of isolated chlorosomes were measured, fitted to gaussian curves and the overlap factors with B795 calculated. Energy transfer times from the bacteriochlorophyll c, d or e to B795 were measured in whole cells and the results interpreted in terms of the Forster theory of energy transfer.

Quantum coherence spectroscopy reveals complex dynamics in bacterial light-harvesting complex 2 (LH2).

PubMed

Harel, Elad; Engel, Gregory S

2012-01-17

Light-harvesting antenna complexes transfer energy from sunlight to photosynthetic reaction centers where charge separation drives cellular metabolism. The process through which pigments transfer excitation energy involves a complex choreography of coherent and incoherent processes mediated by the surrounding protein and solvent environment. The recent discovery of coherent dynamics in photosynthetic light-harvesting antennae has motivated many theoretical models exploring effects of interference in energy transfer phenomena. In this work, we provide experimental evidence of long-lived quantum coherence between the spectrally separated B800 and B850 rings of the light-harvesting complex 2 (LH2) of purple bacteria. Spectrally resolved maps of the detuning, dephasing, and the amplitude of electronic coupling between excitons reveal that different relaxation pathways act in concert for optimal transfer efficiency. Furthermore, maps of the phase of the signal suggest that quantum mechanical interference between different energy transfer pathways may be important even at ambient temperature. Such interference at a product state has already been shown to enhance the quantum efficiency of transfer in theoretical models of closed loop systems such as LH2.

Quantum coherence spectroscopy reveals complex dynamics in bacterial light-harvesting complex 2 (LH2)

PubMed Central

Harel, Elad; Engel, Gregory S.

2012-01-01

Light-harvesting antenna complexes transfer energy from sunlight to photosynthetic reaction centers where charge separation drives cellular metabolism. The process through which pigments transfer excitation energy involves a complex choreography of coherent and incoherent processes mediated by the surrounding protein and solvent environment. The recent discovery of coherent dynamics in photosynthetic light-harvesting antennae has motivated many theoretical models exploring effects of interference in energy transfer phenomena. In this work, we provide experimental evidence of long-lived quantum coherence between the spectrally separated B800 and B850 rings of the light-harvesting complex 2 (LH2) of purple bacteria. Spectrally resolved maps of the detuning, dephasing, and the amplitude of electronic coupling between excitons reveal that different relaxation pathways act in concert for optimal transfer efficiency. Furthermore, maps of the phase of the signal suggest that quantum mechanical interference between different energy transfer pathways may be important even at ambient temperature. Such interference at a product state has already been shown to enhance the quantum efficiency of transfer in theoretical models of closed loop systems such as LH2. PMID:22215585

Formation of Fine B2/ β + O Structure and Enhancement of Hardness in the Aged Ti2AlNb-Based Alloys Prepared by Spark Plasma Sintering

NASA Astrophysics Data System (ADS)

Li, Mengchen; Cai, Qi; Liu, Yongchang; Ma, Zongqing; Wang, Zumin; Huang, Yuan; Li, Huijun

2017-09-01

Ti2AlNb-based alloys synthesized at 1223 K (950 °C) by spark plasma sintering were aged at 973 K, 1023 K, 1073 K, and 1123 K (700 °C, 750 °C, 800 °C, and 850 °C), respectively. Phase composition, microstructure, and microhardness of the aged alloys were investigated in this study. Equiaxed O grains and Widmanstätten B2/ β + O laths were formed in the aged alloys, and the microhardness was improved in contrast with the spark plasma-sintered alloy without aging. The microhardness relies largely on the O-phase content, as well as the length and width of the O laths. In particular, complete Widmanstätten B2/ β + O laths, with locally finely dispersed β precipitates, were obtained in the alloy aged at 1073 K (800 °C), and the alloy exhibited the best microhardness performance. Such fine structure is due to the temperature-dependent transformations Oequiaxed→Oprimary + B2/ β primary, Oprimary→Osecondary + B2/ β secondary, and B2/ β primary→O.

10 CFR 850.2 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Applicability. 850.2 Section 850.2 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM General Provisions § 850.2 Applicability. (a) This... part does not apply to: (1) Beryllium articles; and (2) DOE laboratory operations that meet the...

10 CFR 850.2 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Applicability. 850.2 Section 850.2 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM General Provisions § 850.2 Applicability. (a) This... part does not apply to: (1) Beryllium articles; and (2) DOE laboratory operations that meet the...

11. AERIAL VIEW LOOKING NORTH AT THE BUILDING 800 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. AERIAL VIEW LOOKING NORTH AT THE BUILDING 800 - AREA COMPLEX. ENRICHED URANIUM COMPONENTS WERE MANUFACTURED IN THIS AREA OF THE SITE. BUILDING 881, IN THE RIGHT FOREGROUND OF THE PHOTOGRAPH, WAS THE ORIGINAL PLANT B. BUILDING 883, USED FOR ROLLING AND FORMING URANIUM COMPONENTS, IS DIRECTLY TO THE NORTH OF BUILDING 881. TO THE EAST OF BUILDING 883 IS BUILDING 885, A RESEARCH AND DEVELOPMENT FACILITY FOR ALLOYS AND NON-PLUTONIUM METALS. IN THE FOREGROUND TO THE WEST OF BUILDING 881 IS AN OFFICE BUILDING, 850 (6/7/90). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

30 CFR 800.10 - Information collection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Information collection. 800.10 Section 800.10... collection. The collection of information contained in §§ 800.11, 800.21(c), 800.23(b)(2), 800.23(b)(3), 800... accordance with the requirements of 30 U.S.C. 1201 et seq. Public reporting burden for this collection of...

Temperature Dependence of O2(b1Σ ^+g, v = 0 and 1) Relative Yield in O(1D) + O2 Energy Transfer

NASA Astrophysics Data System (ADS)

Kostko, O.; Raj, S.; Campbell, K.; Pejakovic, D. A.; Kalogerakis, K.

2011-12-01

Energy transfer from excited O(1D) atoms to ground-state O2(X3Σ ^-g) leads to production of O2 in the first two vibrational levels of the O2 (b1Σ ^+g) state: O(1D) + O2 -> O(3P) + O2(b1Σ ^+g, v = 0, 1). Subsequent radiative decay of O2(b1Σ ^+g, v = 0, 1) to the ground state results in the Atmospheric Band emission, a prominent feature of the terrestrial airglow. The relative yield for production of O2(b1Σ ^+g, v = 0 and 1) in the above process, k1/k0, is an important parameter in modeling of the observed Atmospheric Band emission intensities. Recent measurements at room temperature have shown that production of O2(b1Σ ^+g, v = 1) dominates that of O2(b1Σ ^+g, v = 0), with k1/k0 having a value of approximately 3.5 [1]. In the laboratory experiments, the output of a pulsed fluorine laser at 157 nm is used to photodissociate molecular oxygen in an O2/N2 mixture flowing through a heated gas cell. Photodissociation of O2 produces a ground-state O(3P) atom and an excited O(1D) atom. O(1D) rapidly transfers energy to the remaining O2 to produce O2(b1Σ ^+g, v = 0, 1). The populations of O2(b1Σ ^+g, v = 0 and 1) are monitored by observing emissions in the O2(b--X) 0--0 and 1--0 bands at 762 and 688 nm, respectively. The value of k1/k0 is extracted from the time-dependent O2(b1Σ ^+g, v = 0 and 1) fluorescence signals using computer simulations. We will present measurements on the temperature dependence of k1/k0 and discuss their atmospheric significance. This work was supported by the US National Science Foundation (NSF) Aeronomy Program under grant AGS-0937317. The fluorine laser was purchased under grant ATM-0216583 from the NSF Major Research Instrumentation Program. S. Raj and K. M. Campbell participated in a Research Experiences for Undergraduates (REU) site, co-funded by the Division of Physics of the NSF and the Department of Defense in partnership with the NSF REU program under grant PHY-1002892. [1] K. S. Kalogerakis, D. A. Pejaković, R. A. Copeland, T. G

Sintered Cr/Pt and Ni/Au ohmic contacts to B 12P 2

DOE PAGES

Frye, Clint D.; Kucheyev, Sergei O.; Edgar, James H.; ...

2015-04-09

With this study, icosahedral boron phosphide (B 12P 2) is a wide-bandgap semiconductor possessing interesting properties such as high hardness, chemical inertness, and the reported ability to self-heal from irradiation by high energy electrons. Here, the authors developed Cr/Pt and Ni/Au ohmic contacts to epitaxially grown B 12P 2 for materials characterization and electronic device development. Cr/Pt contacts became ohmic after annealing at 700 °C for 30 s with a specific contact resistance of 2×10 –4 Ω cm 2, as measured by the linear transfer length method. Ni/Au contacts were ohmic prior to any annealing, and their minimum specific contactmore » resistance was ~l–4 × 10 –4 Ω cm 2 after annealing over the temperature range of 500–800 °C. Rutherford backscattering spectrometry revealed a strong reaction and intermixing between Cr/Pt and B 12P 2 at 700 °C and a reaction layer between Ni and B 12P 2 thinner than ~25 nm at 500 °C.« less

10 CFR 850.36 - Medical consent.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Medical consent. 850.36 Section 850.36 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.36 Medical... medical surveillance program established in § 850.34 at least one week before the first medical evaluation...

10 CFR 850.36 - Medical consent.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Medical consent. 850.36 Section 850.36 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.36 Medical... medical surveillance program established in § 850.34 at least one week before the first medical evaluation...

10 CFR 850.36 - Medical consent.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Medical consent. 850.36 Section 850.36 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.36 Medical... medical surveillance program established in § 850.34 at least one week before the first medical evaluation...

10 CFR 850.36 - Medical consent.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Medical consent. 850.36 Section 850.36 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.36 Medical... medical surveillance program established in § 850.34 at least one week before the first medical evaluation...

10 CFR 850.36 - Medical consent.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Medical consent. 850.36 Section 850.36 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.36 Medical... medical surveillance program established in § 850.34 at least one week before the first medical evaluation...

Study on photoluminescence and energy transfer of Eu3+/Sm3+ single-doped and co-doped BaB8O13 phosphors

NASA Astrophysics Data System (ADS)

Lephoto, Mantwa A.; Tshabalala, Kamohelo G.; Motloung, Selepe J.; Ahemen, Iorkyaa; Ntwaeaborwa, Odireleng M.

2018-04-01

A series of Sm3+, Eu3+ and Eu3+- Sm3+ doped BaB8O13 were synthesized by using a solution combustion method. When excited at 394 nm, BaB8O13: Eu3+ emits red light, and the strongest peak was located at 614 nm, which is attributed to the 5D0→7F2 transition of Eu3+. BaB8O13: Sm3+ produced red-orange light, and the major emission peak was located at 596 nm under the 402 nm radiation excitation, which is assigned to the 4G5/2→6H7/2 transition of Sm3+. When excited at 402 nm, the PL emission intensity from BaB8O13: 0.05Eu3+; 0.005Sm3+ at 614 nm was enhanced considerably compared to that of the sample without Sm3+, suggesting that energy was transferred from Sm3+ to Eu3+. The Commission International de I‧Eclairage (CIE) chromaticity coordinates of BaB8O13: 0.05Eu3+; 0.005Sm3+ powder phosphor (0.637, 0.362) are located in the red region indicating that the phosphor can serve as a source of red light in LEDs.

Protection against rat vaginal candidiasis by adoptive transfer of vaginal B lymphocytes.

PubMed

De Bernardis, Flavia; Santoni, Giorgio; Boccanera, Maria; Lucciarini, Roberta; Arancia, Silvia; Sandini, Silvia; Amantini, Consuelo; Cassone, Antonio

2010-06-01

Vulvovaginal candidiasis is a mucosal infection affecting many women, but the immune mechanisms operating against Candida albicans at the mucosal level remain unknown. A rat model was employed to further characterize the contribution of B and T cells to anti-Candida vaginal protection. Particularly, the protective role of vaginal B cells was studied by means of adoptive transfer of vaginal CD3(-) CD5(+) IgM(+) cells from Candida-immunized rats to naïve animals. This passive transfer of B cells resulted into a number of vaginal C. albicans CFU approximately 50% lower than their controls. Sorted CD3(-) CD5(+) IgM(+) vaginal B lymphocytes from Candida-infected rats proliferated in response to stimulation with an immunodominant mannoprotein (MP) antigen of the fungus. Importantly, anti-MP antibodies and antibody-secreting B cells were detected in the supernatant and cell cultures, respectively, of vaginal B lymphocytes from infected rats incubated in vitro with vaginal T cells and stimulated with MP. No such specific antibodies were found when using vaginal B cells from uninfected rats. Furthermore, inflammatory and anti-inflammatory cytokines, such as interleukin-2 (IL-2), IL-6 and IL-10, were found in the supernatant of vaginal B cells from infected rats. These data are evidence of a partial anti-Candida protective role of CD3(-) CD5(+) IgM(+) vaginal B lymphocytes in our experimental model.

Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD

DOE PAGES

Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin; ...

2016-11-21

Here, we analyze the energy spectra of single b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the “energy peak” as an observable to determine the top quarkmass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it concerns higher-order QCD effects or newmore » physics contributions. For a 1% jet energy scale uncertainty, the top quark mass can then be extracted using the energy peak of b-jets with an error ±(1.2(exp) + 0.6(th)) GeV. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass.« less

Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin

Here, we analyze the energy spectra of single b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the “energy peak” as an observable to determine the top quarkmass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it concerns higher-order QCD effects or newmore » physics contributions. For a 1% jet energy scale uncertainty, the top quark mass can then be extracted using the energy peak of b-jets with an error ±(1.2(exp) + 0.6(th)) GeV. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass.« less

10 CFR 603.850 - Marking of data.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Other Administrative Matters Intellectual Property § 603.850 Marking of data. To protect the recipient's... protect from disclosure as specified in 10 CFR 600.15(b). [76 FR 26582, May 9, 2011] ...

Mechanisms of charge transfer in human copper ATPases ATP7A and ATP7B.

PubMed

Tadini-Buoninsegni, Francesco; Smeazzetto, Serena

2017-04-01

ATP7A and ATP7B are Cu + -transporting ATPases of subclass IB and play a fundamental role in intracellular copper homeostasis. ATP7A/B transfer Cu + ions across the membrane from delivery to acceptor proteins without establishing a free Cu + gradient. Transfer of copper across the membrane is coupled to ATP hydrolysis. Current measurements on solid supported membranes (SSM) were performed to investigate the mechanism of copper-related charge transfer across ATP7A and ATP7B. SSM measurements demonstrated that electrogenic copper displacement occurs within ATP7A/B following addition of ATP and formation of the phosphorylated intermediate. Comparison of the time constants for cation displacement in ATP7A/B and sarcoplasmic reticulum Ca 2+ -ATPase is consistent with the slower phosphoenzyme formation in copper ATPases. Moreover, ATP-dependent copper transfer in ATP7A/B is not affected by varying the pH, suggesting that net proton counter-transport may not occur in copper ATPases. Platinum anticancer drugs activate ATP7A/B and are subjected to ATP-dependent vectorial displacement with a mechanism analogous to that of copper. © 2016 IUBMB Life, 69(4):218-225, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

10 CFR 850.35 - Medical removal.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Medical removal. 850.35 Section 850.35 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.35 Medical removal. (a) Medical removal protection. The responsible employer must offer a beryllium-associated worker...

10 CFR 850.35 - Medical removal.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Medical removal. 850.35 Section 850.35 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.35 Medical removal. (a) Medical removal protection. The responsible employer must offer a beryllium-associated worker...

10 CFR 850.35 - Medical removal.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Medical removal. 850.35 Section 850.35 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.35 Medical removal. (a) Medical removal protection. The responsible employer must offer a beryllium-associated worker...

10 CFR 850.35 - Medical removal.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Medical removal. 850.35 Section 850.35 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.35 Medical removal. (a) Medical removal protection. The responsible employer must offer a beryllium-associated worker...

10 CFR 850.35 - Medical removal.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Medical removal. 850.35 Section 850.35 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.35 Medical removal. (a) Medical removal protection. The responsible employer must offer a beryllium-associated worker...

10 CFR 850.26 - Regulated areas.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Regulated areas. 850.26 Section 850.26 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.26 Regulated areas. (a) If airborne concentrations of beryllium in areas in DOE facilities are measured at or...

Anchored LH2 complexes in 2D polarization imaging.

PubMed

Tubasum, Sumera; Sakai, Shunsuke; Dewa, Takehisa; Sundström, Villy; Scheblykin, Ivan G; Nango, Mamoru; Pullerits, Tõnu

2013-09-26

Protein is a soft material with inherently large structural disorder. Consequently, the bulk spectroscopies of photosynthetic pigment protein complexes provide averaged information where many details are lost. Here we report spectroscopy of single light-harvesting complexes where fluorescence excitation and detection polarizations are both independently rotated. Two samples of peripheral antenna (LH2) complexes from Rhodopseudomonas acidophila were studied. In one, the complexes were embedded in polyvinyl alcohol (PVA) film; in the other, they were anchored on the glass surface and covered by the PVA film. LH2 contains two rings of pigment molecules-B800 and B850. The B800 excitation polarization properties of the two samples were found to be very similar, indicating that orientation statistics of LH2s are the same in these two very different preparations. At the same time, we found a significant difference in B850 emission polarization statistics. We conclude that the B850 band of the anchored sample is substantially more disordered. We argue that both B800 excitation and B850 emission polarization properties can be explained by the tilt of the anchored LH2s due to the spin-casting of the PVA film on top of the complexes and related shear forces. Due to the tilt, the orientation statistics of two samples become similar. Anchoring is expected to orient the LH2s so that B850 is closer to the substrate. Consequently, the tilt-related strain leads to larger deformation and disorder in B850 than in B800.

Bayesian Atmospheric Radiative Transfer (BART) Code and Application to WASP-43b

NASA Astrophysics Data System (ADS)

Blecic, Jasmina; Harrington, Joseph; Cubillos, Patricio; Bowman, Oliver; Rojo, Patricio; Stemm, Madison; Lust, Nathaniel B.; Challener, Ryan; Foster, Austin James; Foster, Andrew S.; Blumenthal, Sarah D.; Bruce, Dylan

2016-01-01

We present a new open-source Bayesian radiative-transfer framework, Bayesian Atmospheric Radiative Transfer (BART, https://github.com/exosports/BART), and its application to WASP-43b. BART initializes a model for the atmospheric retrieval calculation, generates thousands of theoretical model spectra using parametrized pressure and temperature profiles and line-by-line radiative-transfer calculation, and employs a statistical package to compare the models with the observations. It consists of three self-sufficient modules available to the community under the reproducible-research license, the Thermochemical Equilibrium Abundances module (TEA, https://github.com/dzesmin/TEA, Blecic et al. 2015}, the radiative-transfer module (Transit, https://github.com/exosports/transit), and the Multi-core Markov-chain Monte Carlo statistical module (MCcubed, https://github.com/pcubillos/MCcubed, Cubillos et al. 2015). We applied BART on all available WASP-43b secondary eclipse data from the space- and ground-based observations constraining the temperature-pressure profile and molecular abundances of the dayside atmosphere of WASP-43b. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. JB holds a NASA Earth and Space Science Fellowship.

10 CFR 850.32 - Waste disposal.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Waste disposal. 850.32 Section 850.32 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.32 Waste disposal...-contaminated equipment and other items that are disposed of as waste, through the application of waste...

Hierarchy of stochastic Schrödinger equation towards the calculation of absorption and circular dichroism spectra.

PubMed

Ke, Yaling; Zhao, Yi

2017-05-07

A theoretically solid and numerically exact method is presented for the calculation of absorption and circular dichroism (CD) spectra of molecular aggregates immersed in a harmonic bath constituted as the combination of some prominent quantized vibrational modes and continuous overdamped Brownian oscillators. The feasibility and the validity of newly proposed method are affirmed in the analytical monomer spectra. To go beyond the independent local bath approximation, all the correlations of site energy fluctuations and excitonic coupling fluctuations are included in our strategy, and their influence on the absorption and CD spectra is investigated based on the Frenkel exciton model of homodimer. In the end, a good fit of the absorption and part of CD spectra for the entire B800-B850 ring in the light-harvesting complexes 2 of purple bacteria to the experimental data is given, and the simulation results suggest that the asymmetry in the 800 nm region of CD spectra is actually an indication of B800-B850 inter-ring coupling.

Hierarchy of stochastic Schrödinger equation towards the calculation of absorption and circular dichroism spectra

NASA Astrophysics Data System (ADS)

Ke, Yaling; Zhao, Yi

2017-05-01

A theoretically solid and numerically exact method is presented for the calculation of absorption and circular dichroism (CD) spectra of molecular aggregates immersed in a harmonic bath constituted as the combination of some prominent quantized vibrational modes and continuous overdamped Brownian oscillators. The feasibility and the validity of newly proposed method are affirmed in the analytical monomer spectra. To go beyond the independent local bath approximation, all the correlations of site energy fluctuations and excitonic coupling fluctuations are included in our strategy, and their influence on the absorption and CD spectra is investigated based on the Frenkel exciton model of homodimer. In the end, a good fit of the absorption and part of CD spectra for the entire B800-B850 ring in the light-harvesting complexes 2 of purple bacteria to the experimental data is given, and the simulation results suggest that the asymmetry in the 800 nm region of CD spectra is actually an indication of B800-B850 inter-ring coupling.

10 CFR 850.23 - Action level.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Action level. 850.23 Section 850.23 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.23 Action level. (a) The responsible employer must include in its CBDPP an action level that is no greater than 0.2 µg...

Vibrational and rotational energy transfers involving the CH B 2Σ- v=1 vibrational level in collisions with Ar, CO, and N2O

NASA Astrophysics Data System (ADS)

Huang, Hong-Yi; Tsai, Ming-Tsang; Lin, King-Chuen

2006-04-01

With photolysis-probe technique, we have studied vibrational and rotational energy transfers of CH involving the B Σ-2 (v =1, 0⩽N⩽6, F) state by collisions with Ar, CO, and N2O. For the vibrational energy transfer (VET) measurements, the time-resolved fluorescence of the B-X(0,0) band is monitored following the (1,0) band excitation. For the rotational energy transfer (RET) measurements, the laser-induced fluorescence of the initially populated state is dispersed using a step-scan Fourier transform spectrometer. The time-resolved spectra obtained in the nanosecond regime may yield the RET information under a single pressure of the collider. The rate constants of intramolecular energy transfers are evaluated with simulation of kinetic models. The VET lies in the range of 4×10-12to4×10-11cm3molecule-1s-1, with efficiency following the order of Ar transfer rates decrease with increasing N and ΔN, proceeding via the ΔN =-1 transitions slightly larger than ΔN =+1. With the fine-structure labels resolved up to N =6, the fine-structure-conserving collisions prevail increasingly with increasing N in ΔN ≠0. The rate constants for the F2→F1 transitions are larger than the reverse F1→F2 transitions in ΔN =0 for the Ar and CO collisions. The trend of fine-structure conservation is along the order of N2O

Transition between B-DNA and Z-DNA: free energy landscape for the B-Z junction propagation.

PubMed

Lee, Juyong; Kim, Yang-Gyun; Kim, Kyeong Kyu; Seok, Chaok

2010-08-05

Canonical, right-handed B-DNA can be transformed into noncanonical, left-handed Z-DNA in vitro at high salt concentrations or in vivo under physiological conditions. The molecular mechanism of this drastic conformational transition is still unknown despite numerous studies. Inspired by the crystal structure of a B-Z junction and the previous zipper model, we show here, with the aid of molecular dynamics simulations, that a stepwise propagation of a B-Z junction is a highly probable pathway for the B-Z transition. In this paper, the movement of a B-Z junction by a two-base-pair step in a double-strand nonamer, [d(GpCpGpCpGpCpGpCpG)](2), is considered. Targeted molecular dynamics simulations and umbrella sampling for this transition resulted in a transition pathway with a free energy barrier of 13 kcal/mol. This barrier is much more favorable than those obtained from previous atomistic simulations that lead to concerted transitions of the whole strands. The free energy difference between B-DNA and Z-DNA evaluated from our simulation is 0.9 kcal/mol per dinucleotide unit, which is consistent with previous experiments. The current computation thus strongly supports the proposal that the B-Z transition involves a relatively fast extension of B-DNA or Z-DNA by sequential propagation of B-Z junctions once nucleation of junctions is established.

Vibrational Energy Transfer within the B 3Pi (0(+) sub u) State of 79BR2 Upon Collision with N2, O2, NO, and SF6

DTIC Science & Technology

1993-12-01

molecular radii derived for a (6,12) Lennard - Jones potential from viscosity data tabulated in reference (7). 49 Table A. 1. Gas Kinetic Collision...transfer rates and electronic quenching rates of the diatomic interhalogens in determining potential candidates for visible chemical lasers. This thesis...configuration ..................... 4 2. B2 potential energy curves ................................................................... 5 3. Simplified

High heat transfer oxidizer heat exchanger design and analysis. [RL10-2B engine

NASA Technical Reports Server (NTRS)

Kmiec, Thomas D.; Kanic, Paul G.; Peckham, Richard J.

1987-01-01

The RL10-2B engine, a derivative of the RL10, is capable of multimode thrust operation. This engine operates at two low thrust levels: tank head idle (THI), which is approximately 1 to 2% of full thrust, and pumped idle (PI), which is 10% of full thrust. Operation at THI provides vehicle propellant settling thrust and efficient engine thermal conditioning; PI operation provides vehicle tank pre-pressurization and maneuver thrust for low-g deployment. Stable combustion of the RL10-2B engine during the low thrust operating modes can be accomplished by using a heat exchanger to supply gaseous oxygen to the propellant injector. The oxidizer heat exchanger (OHE) vaporizes the liquid oxygen using hydrogen as the energy source. The design, concept verification testing and analysis for such a heat exchanger is discussed. The design presented uses a high efficiency compact core to vaporize the oxygen, and in the self-contained unit, attenuates any pressure and flow oscillations which result from unstable boiling in the core. This approach is referred to as the high heat transfer design. An alternative approach which prevents unstable boiling of the oxygen by limiting the heat transfer is referred to as the low heat transfer design and is reported in Pratt & Whitney report FR-19135-2.

Atmospheric Retrievals of HAT-P-16b and WASP-11b/HAT-P-10b

NASA Astrophysics Data System (ADS)

McIntyre, Kathleen; Harrington, Joseph; Challener, Ryan; Lenius, Maria; Hartman, Joel D.; Bakos, Gaspar A.; Blecic, Jasmina; Cubillos, Patricio E.; Cameron, Andrew

2018-01-01

We report Bayesian atmospheric retrievals performed on the exoplanets HAT-P-16b and WASP-11b/HAT-P-10b. HAT-P-16b is a hot (equilibrium temperature 1626 ± 40 K, assuming zero Bond albedo and efficient energy redistribution), 4.19 ± 0.09 Jupiter-mass exoplanet orbiting an F8 star every 2.775960 ± 0.000003 days (Buchhave et al 2010). WASP-11b/HAT-P-10b is a cooler (1020 ± 17 K), 0.487 ± 0.018 Jupiter-mass exoplanet orbiting a K3 star every 3.7224747 ± 0.0000065 days (Bakos et al. 2009, co-discovered by West et al. 2008). We observed secondary eclipses of both planets using the 3.6 μm and 4.5 μm channels of the Spitzer Space Telescope's Infrared Array Camera (program ID 60003). We applied our Photometry for Orbits, Eclipses, and Transits (POET) code to produce normalized eclipse light curves, and our Bayesian Atmospheric Radiative Transfer (BART) code to constrain the temperature-pressure profiles and atmospheric molecular abundances of the two planets. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

PubMed

Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

2014-11-01

This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila. Copyright © 2014. Published by Elsevier B.V.

S100a8/NF-κB signal pathway is involved in the 800-nm diode laser-induced skin collagen remodeling.

PubMed

Ren, Xiaolin; Ge, Minggai; Qin, Xiaofeng; Xu, Peng; Zhu, Pingya; Dang, Yongyan; Gu, Jun; Ye, Xiyun

2016-05-01

The 800-nm diode laser is widely used for hair removal and also promotes collagen synthesis, but the molecular mechanism by which dermis responses to the thermal damage induced by the 800-nm diode laser is still unclear. Ten 2-month-old mice were irradiated with the 800-nm diode laser at 20, 40, and 60 J/cm(2), respectively. Skin samples were taken for PCR, Western blot analysis, and histological study at day 3 or 30 after laser irradiation. The expression of S100a8 and its two receptors (advanced glycosylation end product-specific receptor, RAGE and toll-like receptor 4, TRL4) was upregulated at day 3 after laser treatments. P-p65 levels were also elevated, causing the increase of cytokine (tumor necrosis factor, TNF-α and interleukin 6, IL-6) and MMPs (MMP1a, MMP9). At day 30, PCR and Western blot analysis showed significant increase of type I and III procollagen in the dermis treated with laser. Importantly, skin structure was markedly improved in the laser-irradiated skin compared with the control. Thus, it seemed that S100a8 upregulation triggered NF-κB signal pathway through RAGE and TLR4, responding to laser-induced dermis wound healing. The involvement of the NF-κB pathway in MMP gene transcription promoted the turnover of collagen in the skin, accelerating new collagen synthesis.

10 CFR 603.850 - Marking of data.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Marking of data. 603.850 Section 603.850 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Award Terms Related to Other Administrative Matters Intellectual Property § 603.850 Marking of data. To protect the recipient's...

10 CFR 603.850 - Marking of data.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Marking of data. 603.850 Section 603.850 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Award Terms Related to Other Administrative Matters Intellectual Property § 603.850 Marking of data. To protect the recipient's...

10 CFR 850.22 - Permissible exposure limit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Permissible exposure limit. 850.22 Section 850.22 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.22 Permissible exposure limit. The responsible employer must assure that no worker is exposed to an airborne...

B-side charge separation in bacterial photosynthetic reaction centers: nanosecond time scale electron transfer from HB- to QB.

PubMed

Kirmaier, Christine; Laible, Philip D; Hanson, Deborah K; Holten, Dewey

2003-02-25

We report time-resolved optical measurements of the primary electron transfer reactions in Rhodobacter capsulatus reaction centers (RCs) having four mutations: Phe(L181) --> Tyr, Tyr(M208) --> Phe, Leu(M212) --> His, and Trp(M250) --> Val (denoted YFHV). Following direct excitation of the bacteriochlorophyll dimer (P) to its lowest excited singlet state P, electron transfer to the B-side bacteriopheophytin (H(B)) gives P(+)H(B)(-) in approximately 30% yield. When the secondary quinone (Q(B)) site is fully occupied, P(+)H(B)(-) decays with a time constant estimated to be in the range of 1.5-3 ns. In the presence of excess terbutryn, a competitive inhibitor of Q(B) binding, the observed lifetime of P(+)H(B)(-) is noticeably longer and is estimated to be in the range of 4-8 ns. On the basis of these values, the rate constant for P(+)H(B)(-) --> P(+)Q(B)(-) electron transfer is calculated to be between approximately (2 ns)(-)(1) and approximately (12 ns)(-)(1), making it at least an order of magnitude smaller than the rate constant of approximately (200 ps)(-)(1) for electron transfer between the corresponding A-side cofactors (P(+)H(A)(-) --> P(+)Q(A)(-)). Structural and energetic factors associated with electron transfer to Q(B) compared to Q(A) are discussed. Comparison of the P(+)H(B)(-) lifetimes in the presence and absence of terbutryn indicates that the ultimate (i.e., quantum) yield of P(+)Q(B)(-) formation relative to P is 10-25% in the YFHV RC.

High energy phosphate transfer by NDPK B/Gbetagammacomplexes--an alternative signaling pathway involved in the regulation of basal cAMP production.

PubMed

Hippe, Hans-Joerg; Wieland, Thomas

2006-08-01

The activation of heterotrimeric G proteins induced by G protein coupled receptors (GPCR) is generally believed to occur by a GDP/GTP exchange at the G protein alpha -subunit. Nevertheless, nucleoside diphosphate kinase (NDPK) and the beta-subunit of G proteins (Gbeta) participate in G protein activation by phosphate transfer reactions leading to the formation of GTP from GDP. Recent work elucidated the role of these reactions. Apparently, the NDPK isoform B (NDPK B) forms a complex with Gbetagamma dimers in which NDPK B acts as a histidine kinase phosphorylating Gbeta at His266. Out of this high energetic phosphoamidate bond the phosphate can be transferred specifically onto GDP. The formed GTP binds to the G protein alpha-subunit and thus activates the respective G protein. Evidence is presented, that this process occurs independent of the classical GPCR-induced GTP/GTP exchange und thus contributes, e.g. to the regulation of basal cAMP synthesis in cells.

Fluorescence properties and energy transfer study of Er3+/Nd3+ doped fluorophosphate glass pumped at 800 and 980 nm for mid-infrared laser applications

NASA Astrophysics Data System (ADS)

Tian, Ying; Xu, Rongrong; Hu, Lili; Zhang, Junjie

2012-04-01

The fluorescence properties of 2.7 μm emission as well as near infrared emissions in Er3+/Nd3+ doped fluorophosphate glasses are investigated under 800 and 980 nm excitation. The fluorescence dynamics and energy transfer processes between Er and Nd ions in different pumping schemes are reported. Three Judd-Ofelt intensity parameters, energy transfer microparameters, and efficiency have been determined using the Judd-Ofelt and Förster-Dexter theories. The calculated energy transfer efficiency of the Er3+:4I13/2 level to the Nd3+:4I15/2 level is as high as 83.91%. The results indicate that Nd3+ may be an efficient sensitizer for Er3+ to obtain mid-infrared emission and the more suitable pumping scheme of 2.7 μm laser applications for Er3+/Nd3+ doped fluorophosphate glass is 980 nm excitation.

Submicron R2Fe14B particles

NASA Astrophysics Data System (ADS)

Koylu-Alkan, O.; Barandiaran, J. M.; Salazar, D.; Hadjipanayis, G. C.

2016-05-01

Mechanochemical synthesis of submicron R2Fe14B particles with R = Dy, Nd, Pr has been performed successfully via high energy ball milling of rare-earth oxides, iron oxide and boron oxide in the presence of a reducing agent (Ca) and a dispersant material (CaO), followed by annealing at 800 - 900 °C. In the R = Nd system, we were able to fabricate particles embedded in a CaO matrix with coercivity (Hc) of 10.3 kOe after annealing at 900 °C for 5 min. After washing off the dispersant, the Hc was decreased to below 1 kOe because of hydrogen absorption that leads to the formation of the hydrated R2Fe14BHx phase that has a lower anisotropy. Upon removal of the hydrogen the coercivity was increased to 3.3 kOe. The average size of the Nd2Fe14B particles increases from 100 nm in a sample synthesized at 800 °C to 158 nm at 900 °C. The isotropic Dy2Fe14B particles showed a higher coercivity of 21 kOe in washed samples after annealing at 900 °C for 5 min. An average size of 71 nm is measured in samples synthesized at 800 °C and 107 nm at 900 °C. Fitting the high field M(H) measurements in Nd2Fe14B to the law of approach to saturation gave values for the magnetocrystalline anisotropy for the washed sample 2.23 × 107 erg/cm3 and for the vacuum annealed sample 4.15 × 107 erg/cm3, both of which are lower than the bulk values. This would explain the lower values of Hc observed in the particles.

Elastic and inelastic scattering for the 10B+58Ni system at near-barrier energies

NASA Astrophysics Data System (ADS)

Scarduelli, V.; Crema, E.; Guimarães, V.; Abriola, D.; Arazi, A.; de Barbará, E.; Capurro, O. A.; Cardona, M. A.; Gallardo, J.; Hojman, D.; Martí, G. V.; Pacheco, A. J.; Rodrígues, D.; Yang, Y. Y.; Deshmukh, N. N.; Paes, B.; Lubian, J.; Mendes Junior, D. R.; Morcelle, V.; Monteiro, D. S.

2017-11-01

Full angular distributions of the 10B elastically and inelastically scattered by 58Ni have been measured at different energies around the Coulomb barrier. The elastic and inelastic scattering of 10B on a medium mass target has been measured for the first time. The obtained angular distributions have been analyzed in terms of large-scale coupled reaction channel calculations, where several inelastic transitions of the projectile and the target, as well as the most relevant one- and two-step transfer reactions have been included in the coupling matrix. The roles of the spin reorientation, the spin-orbit interaction, and the large ground-state deformation of the 10B, in the reaction mechanism, were also investigated. The real part of the interaction potential between projectile and target was represented by a parameter-free double-folding potential, whereas no imaginary potential at the surface was considered. In this sense, the theoretical calculations were parameter free and their results were compared to experimental data to investigate the relative importance of the different reaction channels. A striking influence of the ground-state spin reorientation of the 10B nucleus was found, while all transfer reactions investigated had a minimum contribution to the dynamics of the system. Finally, the large static deformation of the 10B and the spin-orbit coupling can also play an important role in the system studied.

Fluctuation-induced shear flow and energy transfer in plasma interchange turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, B.; Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Sun, C. K.

2015-11-15

Fluctuation-induced E × B shear flow and energy transfer for plasma interchange turbulence are examined in a flux-driven system with both closed and open magnetic field lines. The nonlinear evolution of interchange turbulence shows the presence of two confinement regimes characterized by low and high E × B flow shear. In the first regime, the large-scale turbulent convection is dominant and the mean E × B shear flow is at a relatively low level. By increasing the heat flux above a certain threshold, the increased turbulent intensity gives rise to the transfer of energy from fluctuations to mean E ×more » B flows. As a result, a transition to the second regime occurs, in which a strong mean E × B shear flow is generated.« less

Quinone reduction via secondary B-branch electron transfer in mutant bacterial reaction centers.

PubMed

Laible, Philip D; Kirmaier, Christine; Udawatte, Chandani S M; Hofman, Samuel J; Holten, Dewey; Hanson, Deborah K

2003-02-18

Symmetry-related branches of electron-transfer cofactors-initiating with a primary electron donor (P) and terminating in quinone acceptors (Q)-are common features of photosynthetic reaction centers (RC). Experimental observations show activity of only one of them-the A branch-in wild-type bacterial RCs. In a mutant RC, we now demonstrate that electron transfer can occur along the entire, normally inactive B-branch pathway to reduce the terminal acceptor Q(B) on the time scale of nanoseconds. The transmembrane charge-separated state P(+)Q(B)(-) is created in this manner in a Rhodobacter capsulatus RC containing the F(L181)Y-Y(M208)F-L(M212)H-W(M250)V mutations (YFHV). The W(M250)V mutation quantitatively blocks binding of Q(A), thereby eliminating Q(B) reduction via the normal A-branch pathway. Full occupancy of the Q(B) site by the native UQ(10) is ensured (without the necessity of reconstitution by exogenous quinone) by purification of RCs with the mild detergent, Deriphat 160-C. The lifetime of P(+)Q(B)(-) in the YFHV mutant RC is >6 s (at pH 8.0, 298 K). This charge-separated state is not formed upon addition of competitive inhibitors of Q(B) binding (terbutryn or stigmatellin). Furthermore, this lifetime is much longer than the value of approximately 1-1.5 s found when P(+)Q(B)(-) is produced in the wild-type RC by A-side activity alone. Collectively, these results demonstrate that P(+)Q(B)(-) is formed solely by activity of the B-branch carriers in the YFHV RC. In comparison, P(+)Q(B)(-) can form by either the A or B branches in the YFH RC, as indicated by the biexponential lifetimes of approximately 1 and approximately 6-10 s. These findings suggest that P(+)Q(B)(-) states formed via the two branches are distinct and that P(+)Q(B)(-) formed by the B side does not decay via the normal (indirect) pathway that utilizes the A-side cofactors when present. These differences may report on structural and energetic factors that further distinguish the functional

On the transferability of electron density in binary vanadium borides VB, V3B4 and VB2.

PubMed

Terlan, Bürgehan; Akselrud, Lev; Baranov, Alexey I; Borrmann, Horst; Grin, Yuri

2015-12-01

Binary vanadium borides are suitable model systems for a systematic analysis of the transferability concept in intermetallic compounds due to chemical intergrowth in their crystal structures. In order to underline this structural relationship, topological properties of the electron density in VB, V3B4 and VB2 reconstructed from high-resolution single-crystal X-ray diffraction data as well as derived from quantum chemical calculations, are analysed in terms of Bader's Quantum Theory of Atoms in Molecules [Bader (1990). Atoms in Molecules: A Quantum Theory, 1st ed. Oxford: Clarendon Press]. The compounds VB, V3B4 and VB2 are characterized by a charge transfer from the metal to boron together with two predominant atomic interactions, the shared covalent B-B interactions and the polar covalent B-M interactions. The resembling features of the crystal structures are well reflected by the respective B-B interatomic distances as well as by ρ(r) values at the B-B bond critical points. The latter decrease with an increase in the corresponding interatomic distances. The B-B bonds show transferable electron density properties at bond critical points depending on the respective bond distances.

Effective adoptive transfer of haploidentical tumor-specific T cells in B16-melanoma bearing mice.

PubMed

Cui, Nai-peng; Xie, Shao-jian; Han, Jin-sheng; Ma, Zhen-feng; Chen, Bao-ping; Cai, Jian-hui

2012-03-01

Adoptive transfer of allogeneic tumor-specific T cells often results in severe graft-versus-host disease (GVHD). Here, we sought to maximize graft-versus-tumor and minimize GVHD by using haploidentical T cells in pre-irradiated B16-melanoma bearing mice. C57BL/6 mice bearing B16-melanoma tumors were irradiated with 0, 5, or 7 Gy total body irradiation (TBI), or 7 Gy TBI plus bone marrow transplantation. Tumor areas were measured every 3 days to assess the influence of irradiation treatment on tumor regression. B16-melanoma bearing mice were irradiated with 7 Gy TBI; sera and spleens were harvested at days 1, 3, 5, 7, 9, 11, and 13 after irradiation. White blood cell levels were measured and transforming growth factor β1 (TGF-b1) and interleukin 10 (IL-10) levels in serum were detected using enzyme-linked immunosorbent assay (ELISA) kits. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry were performed to test TGF-b1, IL-10 and Foxp3 mRNA levels and the proportion of CD4+CD25+Foxp3+ T-regulatory cells (Tregs) in spleens. B16-melanoma bearing C57BL/6 mice were irradiated with 7 Gy TBI followed by syngeneic (Syn1/Syn2) or haploidentical (Hap1/Hap2), dendritic cell-induced cytotoxic T lymphocytes (DC-CTLs) treatment, tumor areas and system GVHD were observed every 3 days. Mice were killed 21 days after the DC-CTLs adoptive transfer; histologic analyses of eyes, skin, liver, lungs, and intestine were then performed. Irradiation with 7 Gy TBI on the B16-melanoma-bearing mice did not influence tumor regression compared to the control group; however, it down-regulated the proportion of Tregs in spleens and the TGF-b1 and IL-10 levels in sera and spleens, suggesting inhibition of autoimmunity and intervention of tumor microenvironment. Adoptive transfer of haploidentical DC-CTLs significantly inhibited B16-melanoma growth. GVHD assessment and histology analysis showed no significant difference among the groups. Adoptive transfer of

Identification and characterization of B cell precursors in rat lymphoid tissues. I. Adoptive transfer assays for precursors of TI-1, TI-2, and TD antigen-reactive B cells.

PubMed

Whalen, B J; Goldschneider, I

1993-10-01

Quantitative adoptive transfer assays were developed to detect the precursors of TI-1, TI-2, and TD antigen-reactive B cells in rat lymphoid tissues. Studies on the immune responses in normal and athymic nude rats validate the use of TNP-lipopolysaccharide as a TI-1 antigen, TNP-Ficoll as a TI-2 antigen, and SRBC as a TD antigen in rats. The precursors to these immunologically competent B cells are detected, following transfer into irradiated histocompatible recipients, by their ability to generate expanded populations of antigen-reactive B cells capable of mounting antibody responses (splenic IgM plaque-forming cells) to these antigens. Maximal numbers of antigen-reactive B cells emerge in antigenically naive rats after an interval of 7-12 days following transfer of donor lymphoid cells and decline rapidly thereafter. The delayed responses in adoptive recipients reconstituted with spleen cells are proportional to the numbers of spleen cells transferred and are shown to be primarily donor derived using histocompatible Ig kappa chain alloantigen disparate rat strain combinations. The precursors of TI-1, TI-2, and TD antigen-reactive B cells are present in both donor spleen and bone marrow. However, precursor cells to TI-1 and TD antigens are largely absent from donor lymph node cells, whereas precursors to the TI-2 antigen are as prevalent in donor lymph node as in donor spleen. These results support the hypothesis that newly formed virginal B cells represent transient populations of precursor cells that undergo further proliferation and differentiation in the spleen before acquiring immunological competence. The results also suggest that the precursors of TI-2 antigen-reactive B cells differ developmentally from those of TI-1 and TD antigen-reactive B cells, and that the antigen-reactive progeny of these precursors require additional stimulation in order to join the pool of long-lived peripheral B cells.

Occurrence of the Transferable Copper Resistance Gene tcrB among Fecal Enterococci of U.S. Feedlot Cattle Fed Copper-Supplemented Diets

PubMed Central

Amachawadi, R. G.; Alvarado, C. A.; Mainini, T. R.; Vinasco, J.; Drouillard, J. S.; Nagaraja, T. G.

2013-01-01

Copper, an essential micronutrient, is supplemented in the diet at elevated levels to reduce morbidity and mortality and to promote growth in feedlot cattle. Gut bacteria exposed to copper can acquire resistance, which among enterococci is conferred by a transferable copper resistance gene (tcrB) borne on a plasmid. The present study was undertaken to investigate whether the feeding of copper at levels sufficient to promote growth increases the prevalence of the tcrB gene among the fecal enterococci of feedlot cattle. The study was performed with 261 crossbred yearling heifers housed in 24 pens, with pens assigned randomly to a 2×2 factorial arrangement of treatments consisting of dietary copper and a commercial linseed meal-based energy protein supplement. A total of 22 isolates, each identified as Enterococcus faecium, were positive for tcrB with an overall prevalence of 3.8% (22/576). The prevalence was higher among the cattle fed diets supplemented with copper (6.9%) compared to normal copper levels (0.7%). The tcrB-positive isolates always contained both erm(B) and tet(M) genes. Median copper MICs for tcrB-positive and tcrB-negative enterococci were 22 and 4 mM, respectively. The transferability of the tcrB gene was demonstrated via a filter-mating assay. Multilocus variable number tandem repeat analysis revealed a genetically diverse population of enterococci. The finding of a strong association between the copper resistance gene and other antibiotic (tetracycline and tylosin) resistance determinants is significant because enterococci remain potential pathogens and have the propensity to transfer resistance genes to other bacteria in the gut. PMID:23666328

10 CFR 850.27 - Hygiene facilities and practices.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Hygiene facilities and practices. 850.27 Section 850.27 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.27 Hygiene facilities and practices. (a) General. The responsible employer must assure that in...

Electrostatic redesign of the [myoglobin, cytochrome b5] interface to create a well-defined docked complex with rapid interprotein electron transfer.

PubMed

Xiong, Peng; Nocek, Judith M; Griffin, Amanda K K; Wang, Jingyun; Hoffman, Brian M

2009-05-27

Cyt b(5) is the electron-carrier "repair" protein that reduces met-Mb and met-Hb to their O(2)-carrying ferroheme forms. Studies of electron transfer (ET) between Mb and cyt b(5) revealed that they react on a "Dynamic Docking" (DD) energy landscape on which binding and reactivity are uncoupled: binding is weak and involves an ensemble of nearly isoenergetic configurations, only a few of which are reactive; those few contribute negligibly to binding. We set the task of redesigning the surface of Mb so that its reaction with cyt b(5) instead would occur on a conventional "simple docking" (SD) energy landscape, on which a complex exhibits a well-defined (set of) reactive binding configuration(s), with binding and reactivity thus no longer being decoupled. We prepared a myoglobin (Mb) triple mutant (D44K/D60K/E85K; Mb(+6)) substituted with Zn-deuteroporphyrin and monitored cytochrome b(5) (cyt b(5)) binding and electron transfer (ET) quenching of the (3)ZnMb(+6) triplet state. In contrast, to Mb(WT), the three charge reversals around the "front-face" heme edge of Mb(+6) have directed cyt b(5) to a surface area of Mb adjacent to its heme, created a well-defined, most-stable structure that supports good ET pathways, and apparently coupled binding and ET: both K(a) and k(et) are increased by the same factor of approximately 2 x 10(2), creating a complex that exhibits a large ET rate constant, k(et) = 10(6 1) s(-1), and is in slow exchange (k(off) < k(et)). In short, these mutations indeed appear to have created the sought-for conversion from DD to simple docking (SD) energy landscapes.

Studies of hot B subdwarfs. II - Energy distributions of three bright sdB/sdOB stars in the 950-5500 A range

NASA Technical Reports Server (NTRS)

Wesemael, F.; Veilleux, S.; Lamontagne, R.; Fontaine, G.; Holberg, J. B.

1985-01-01

Voyager ultraviolet spectrometer observations of the subdwarf B or OB stars HD 205805, UV 1758+36 and Feige 66 are presented. All three objects display the H I Layman series in absorption. These observations are combined with low dispersion IUE spectrophotometry and with Stromgren photometry to construct virtually complete energy distributions, which extend over the range 950-5500 angstroms. Effective temperatures based on model atmosphere calculations for high gravity, hygrogen rich stars are determined. Our analyses yield T sub e 28,200 + or - 1300 K for HD 205805, T sub e 31, 800 + or - 1100 K for UV 1758+36, and T sub e 35,700 + or 1500 K for Feige 66. The importance of far ultraviolet observations below L sub alpha in reducing the uncertainties associated with the interstellar extinction and the degradation of the IUE sensitivity is emphasized.

Validation of the Pangao PG-800B11 blood pressure monitor according to the European Society of Hypertension and the British Hypertension Society protocols.

PubMed

Bing, Sen; Zhang, Cunhai; Wang, Liping; Li, Linyi; Wan, Yi

2014-12-01

The study aimed to determine the accuracy of the fully automated oscillometric upper-arm blood pressure (BP) monitor Pangao PG-800B11 according to the European Society of Hypertension-International Protocol (ESH-IP) revision 2010 and the British Hypertension Society (BHS) protocol 1993. Data from 33 participants were initially examined according to the ESH-IP revision 2010. Furthermore, 52 participants were then enrolled to fulfill the BHS protocol requirements. In all participants, sequential left arm measurements were performed by two trained observers using a mercury sphygmomanometer and one supervisor using the device. The protocols' requirements were followed precisely. The device passed all parts of the ESH protocol for systolic blood pressure (SBP) and diastolic blood pressure (DBP) and was graded A according to the criteria of the BHS protocol for both SBP and DBP. The A/A grade was achieved in low (<130/80 mmHg), medium (130-160/80-100 mmHg), and high (>160/100 mmHg) BP categories. The mean BP difference between PG-800B11 and observers in the 85 participants was -0.6±5.0 mmHg for SBP and -0.6±4.5 mmHg for DBP; thus, the device also fulfilled the requirements of the Association for the Advancement of Medical Instrumentation (AAMI). The Pangao PG-800B11 passed all requirements of the ESH-IP revision 2010 and achieved A/A grade of the BHS protocol across a wide range of BPs.

10 CFR 603.850 - Marking of data.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Marking of data. 603.850 Section 603.850 Energy DEPARTMENT... Other Administrative Matters Intellectual Property § 603.850 Marking of data. To protect the recipient's interests in data, the TIA should require the recipient to mark any particular data that it wishes to...

10 CFR 603.850 - Marking of data.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Marking of data. 603.850 Section 603.850 Energy DEPARTMENT... Other Administrative Matters Intellectual Property § 603.850 Marking of data. To protect the recipient's interests in data, the TIA should require the recipient to mark any particular data that it wishes to...

Computational Approach to Explore the B/A Junction Free Energy in DNA.

PubMed

Kulkarni, Mandar; Mukherjee, Arnab

2016-01-04

Protein-DNA interactions induce conformational changes in DNA such as B- to A-form transitions at a local level. Such transitions are associated with a junction free energy cost at the boundary of two different conformations in a DNA molecule. In this study, we performed umbrella sampling simulations to find the free energy values of the B-A transition at the dinucleotide and trinucleotide level of DNA. Using a combination of dinucleotide and trinucleotide free energy costs obtained from simulations, we calculated the B/A junction free energy. Our study shows that the B/A junction free energy is 0.52 kcal mol(-1) for the A-philic GG step and 1.59 kcal mol(-1) for the B-philic AA step. This observation is in agreement with experimentally derived values. After excluding junction effects, we obtained an absolute free energy cost for the B- to A-form conversion for all the dinucleotide steps. These absolute free energies may be used for predicting the propensity of structural transitions in DNA. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Grid of Supergiant B[e] Models from HDUST Radiative Transfer

NASA Astrophysics Data System (ADS)

Domiciano de Souza, A.; Carciofi, A. C.

2012-12-01

By using the Monte Carlo radiative transfer code HDUST (developed by A. C. Carciofi and J..E. Bjorkman) we have built a grid of models for stars presenting the B[e] phenomenon and a bimodal outflowing envelope. The models are particularly adapted to the study of B[e] supergiants and FS CMa type stars. The adopted physical parameters of the calculated models make the grid well adapted to interpret high angular and high spectral observations, in particular spectro-interferometric data from ESO-VLTI instruments AMBER (near-IR at low and medium spectral resolution) and MIDI (mid-IR at low spectral resolution). The grid models include, for example, a central B star with different effective temperatures, a gas (hydrogen) and silicate dust circumstellar envelope with a bimodal mass loss presenting dust in the denser equatorial regions. The HDUST grid models were pre-calculated using the high performance parallel computing facility Mésocentre SIGAMM, located at OCA, France.

Exploring the energy landscape for Q(A)(-) to Q(B) electron transfer in bacterial photosynthetic reaction centers: effect of substrate position and tail length on the conformational gating step.

PubMed

Xu, Qiang; Baciou, Laura; Sebban, Pierre; Gunner, M R

2002-08-06

The ability to initiate reactions with a flash of light and to monitor reactions over a wide temperature range allows detailed analysis of reaction mechanisms in photosynthetic reaction centers (RCs) of purple bacteria. In this protein, the electron transfer from the reduced primary quinone (Q(A)(-)) to the secondary quinone (Q(B)) is rate-limited by conformational changes rather than electron tunneling. Q(B) movement from a distal to a proximal site has been proposed to be the rate-limiting change. The importance of quinone motion was examined by shortening the Q(B) tail from 50 to 5 carbons. No change in rate was found from 100 to 300 K. The temperature dependence of the rate was also measured in three L209 proline mutants. Under conditions where Q(B) is in the distal site in wild-type RCs, it is trapped in the proximal site in the Tyr L209 mutant [Kuglstatter, A., et al. (2001) Biochemistry 40, 4253-4260]. The electron transfer slows at low temperature for all three mutants as it does in wild-type protein, indicating that conformational changes still limit the reaction rate. Thus, Q(B) movement is unlikely to be the sole, rate-limiting conformational gating step. The temperature dependence of the reaction in the L209 mutants differs somewhat from wild-type RCs. Entropy-enthalpy compensation reduces the difference in rates and free energy changes at room temperature.

10 CFR 850.28 - Respiratory protection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Respiratory protection. 850.28 Section 850.28 Energy... Respiratory protection. (a) The responsible employer must establish a respiratory protection program that complies with the respiratory protection program requirements of 29 CFR 1910.134, Respiratory Protection...

10 CFR 850.28 - Respiratory protection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Respiratory protection. 850.28 Section 850.28 Energy... Respiratory protection. (a) The responsible employer must establish a respiratory protection program that complies with the respiratory protection program requirements of 29 CFR 1910.134, Respiratory Protection...

10 CFR 850.28 - Respiratory protection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Respiratory protection. 850.28 Section 850.28 Energy... Respiratory protection. (a) The responsible employer must establish a respiratory protection program that complies with the respiratory protection program requirements of 29 CFR 1910.134, Respiratory Protection...

10 CFR 850.28 - Respiratory protection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Respiratory protection. 850.28 Section 850.28 Energy... Respiratory protection. (a) The responsible employer must establish a respiratory protection program that complies with the respiratory protection program requirements of 29 CFR 1910.134, Respiratory Protection...

10 CFR 850.28 - Respiratory protection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Respiratory protection. 850.28 Section 850.28 Energy... Respiratory protection. (a) The responsible employer must establish a respiratory protection program that complies with the respiratory protection program requirements of 29 CFR 1910.134, Respiratory Protection...

Paleoeskimo Demographic History in the Canadian Arctic (ca. 4800-800 B.P.) and its Relationship to Mid-Late Holocene Climate Variability.

NASA Astrophysics Data System (ADS)

Savelle, J. M.

2014-12-01

Paleoeskimos were the first occupants of the central and eastern Canadian Arctic, spreading east from the Bering Strait region beginning approximately 4800 B.P., and occupied much of the Canadian Arctic through to their eventual disappearance ca. 800 B.P. Extensive regional archaeological site surveys throughout this area by the author and Arthur S. Dyke indicate that Paleoskimo populations underwent a series of population 'boom' (rapid expansion) and 'bust' (population declines and local extinctions) over the 4,000 year occupation history, including in the purported stable 'core area' of Foxe Basin. In this paper, we examine the contemporaneity of the local boom and bust cycles in a pan-Canadian Arctic context, and in turn examine the relationship of these cycles to mid-late Holocene climate variability.

Study of b\\overline{b} correlations in high energy proton-proton collisions

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baryshnikov, F.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M.-O.; van Beuzekom, M.; Bezshyiko, Ia.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Bjørn, M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Bordyuzhin, I.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britton, T.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Chapman, M. G.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chitic, S.-G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Ciambrone, P.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H.-P.; Demmer, M.; Dendek, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Durante, P.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Funk, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Griffith, P.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; Hancock, T. H.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hasse, C.; Hatch, M.; He, J.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, P. H.; Huard, Z. C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kazeev, N.; Kecke, M.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Komarov, I.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; Kravchuk, L.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, P.-R.; Li, T.; Li, Y.; Li, Z.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Lisovskyi, V.; Liu, X.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Luchinsky, A.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; Mackowiak, P.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M.-N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombächer, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, T. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pisani, F.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Robert, A.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepulveda, E. S.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Soares Lavra, l.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stepanova, M.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Toriello, F.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Usachov, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Winn, M.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhu, X.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.

2017-11-01

Kinematic correlations for pairs of beauty hadrons, produced in high energy proton-proton collisions, are studied. The data sample used was collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3 fb-1. The measurement is performed using inclusive b → J/ ψX decays in the rapidity range 2 < y J/ ψ < 4.5. The observed correlations are in good agreement with theoretical predictions. [Figure not available: see fulltext.

Studies of hot B subdwarfs. Part 2: Energy distributions of three bright sdB/sdOB stars in the 950-5500 angstrom range

NASA Technical Reports Server (NTRS)

Wesemael, F.; Holberg, J. B.; Veilleux, S.; Lamontagne, R.; Fontaine, G.

1985-01-01

Voyager ultraviolet spectrometer observations of the subdwarf B or OB stars HD 205805, UV 1758+36 and Feige 66 are presented. All three objects display the H I Layman series in absorption. These observations are combined with low dispersion IUE spectrophotometry and with Stroemgren photometry to construct virtually complete energy distributions, which extend over the range 950-5500 angstroms. Effective temperatures based on model atmosphere calculations for high gravity, hydrogen rich stars are determined. Our analyses yield T Sub e 28,200 + or - 1300 K for HD 205805, T sub e 31, 800 + or - 1100 K for UV 1758+36, and T sub e 35,700 + or - 1500 K for Feige 66. The importance of far ultraviolet observations below L sub alpha in reducing the uncertainties associated with the interstellar extinction and the degradation of the IUE sensitivity is emphasized.

10 CFR 850.21 - Hazard assessment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Hazard assessment. 850.21 Section 850.21 Energy DEPARTMENT... assessment. (a) If the baseline inventory establishes the presence of beryllium, the responsible employer must conduct a beryllium hazard assessment that includes an analysis of existing conditions, exposure...

Resonant electronic excitation energy transfer by Dexter mechanism in the quantum dot system

NASA Astrophysics Data System (ADS)

Samosvat, D. M.; Chikalova-Luzina, O. P.; Vyatkin, V. M.; Zegrya, G. G.

2016-11-01

In present work the energy transfer between quantum dots by the exchange (Dexter) mechanism is analysed. The interdot Coulomb interaction is taken into consideration. It is assumed that the quantum dot-donor and the quantum dot-acceptor are made from the same compound A3B5 and embedded in the matrix of other material creating potential barriers for electron and holes. The dependences of the energy transfer rate on the quantum-dot system parameters are found using the Kane model that provides the most adequate description spectra of semiconductors A3B5. Numerical calculations show that the rate of the energy transfer by Dexter mechanism is comparable to the rate of the energy transfer by electrostatic mechanism at the distances approaching to the contact ones.

Contribution of Electrostatics to the Kinetics of Electron Transfer from NADH-Cytochrome b5 Reductase to Fe(III)-Cytochrome b5.

PubMed

Kollipara, Sireesha; Tatireddy, Shivakishore; Pathirathne, Thusitha; Rathnayake, Lasantha K; Northrup, Scott H

2016-08-25

Brownian dynamics (BD) simulations provide here a theoretical atomic-level treatment of the reduction of human ferric cytochrome b5 (cyt b5) by NADH-cytochrome b5 reductaste (cyt b5r) and several of its mutants. BD is used to calculate the second-order rate constant of electron transfer (ET) between the proteins for direct correlation with experiments. Interestingly, the inclusion of electrostatic forces dramatically increases the reaction rate of the native proteins despite the overall negative charge of both proteins. The role played by electrostatic charge distribution in stabilizing the ET complexes and the role of mutations of several amino acid residues in stabilizing or destabilizing the complexes are analyzed. The complex with the shortest ET reaction distance (d = 6.58 Å) from rigid body BD is further subjected to 1 ns of molecular dynamics (MD) in a periodic box of TIP3P water to produce a more stable complex allowed by flexibility and with a shorter average reaction distance d = 6.02 Å. We predict a docking model in which the following ion-ion interactions are dominant (cyt b5r/cyt b5): Lys162-Heme O1D/Lys163-Asp64/Arg91-Heme O1A/Lys125-Asp70.

Blood group genotyping for Jk(a)/Jk(b), Fy(a)/Fy(b), S/s, K/k, Kp(a)/Kp(b), Js(a)/Js(b), Co(a)/Co(b), and Lu(a)/Lu(b) with microarray beads.

PubMed

Karpasitou, Katerina; Drago, Francesca; Crespiatico, Loretta; Paccapelo, Cinzia; Truglio, Francesca; Frison, Sara; Scalamogna, Mario; Poli, Francesca

2008-03-01

Traditionally, blood group typing has been performed with serologic techniques, the classical method being the hemagglutination test. Serotyping, however, may present important limitations such as scarce availability of rare antisera, typing of recently transfused patients, and those with a positive direct antiglobulin test. Consequently, serologic tests are being complemented with molecular methods. The aim of this study was to develop a low-cost, high-throughput method for large-scale genotyping of red blood cells (RBCs). Single-nucleotide polymorphisms associated with some clinically important blood group antigens, as well as with certain rare blood antigens, were evaluated: Jk(a)/Jk(b), Fy(a)/Fy(b), S/s, K/k, Kp(a)/Kp(b), Js(a)/Js(b), Co(a)/Co(b), and Lu(a)/Lu(b). Polymerase chain reaction (PCR)-amplified targets were detected by direct hybridization to microspheres coupled to allele-specific oligonucleotides. Cutoff values for each genotype were established with phenotyped and/or genotyped samples. The method was validated with a blind panel of 92 blood donor samples. The results were fully concordant with those provided by hemagglutination assays and/or sequence-specific primer (SSP)-PCR. The method was subsequently evaluated with approximately 800 blood donor and patient samples. This study presents a flexible, quick, and economical method for complete genotyping of large donor cohorts for RBC alleles.

Phylogenetic analysis of Mycobacterium massiliense strains having recombinant rpoB gene laterally transferred from Mycobacterium abscessus.

PubMed

Kim, Byoung-Jun; Kim, Ga-Na; Kim, Bo-Ram; Shim, Tae-Sun; Kook, Yoon-Hoh; Kim, Bum-Joon

2017-01-01

Recent multi locus sequence typing (MLST) and genome based studies indicate that lateral gene transfer (LGT) events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas), we applied rpoB typing (711 bp) to 106 Korean strains of M. massiliense infection that had already been identified by hsp65 sequence analysis (603 bp). The analysis indicated 6 smooth strains in M. massiliense Type I (10.0%, 6/60) genotypes but no strains in M. massiliense Type II genotypes (0%, 0/46), showing a discrepancy between the 2 typing methods. Further MLST analysis based on the partial sequencing of seven housekeeping genes, argH, cya, glpK, gnd, murC, pta and purH, as well as erm(41) PCR proved that these 6 Rec-mas strains consisted of two distinct genotypes belonging to M. massiliense and not M. abscessus. The complete rpoB sequencing analysis showed that these 6 Rec-mas strains have an identical hybrid rpoB gene, of which a 478 bp partial rpoB fragment may be laterally transferred from M. abscessus. Notably, five of the 6 Rec-mas strains showed complete identical sequences in a total of nine genes, including the seven MLST genes, hsp65, and rpoB, suggesting their clonal propagation in South Korea. In conclusion, we identified 6 M. massiliense smooth strains of 2 phylogenetically distinct genotypes with a specific hybrid rpoB gene laterally transferred from M. abscessus from Korean patients. Their clinical relevance and bacteriological traits remain to be elucidated.

Phylogenetic analysis of Mycobacterium massiliense strains having recombinant rpoB gene laterally transferred from Mycobacterium abscessus

PubMed Central

Kim, Byoung-Jun; Kim, Ga-Na; Kim, Bo-Ram; Shim, Tae-Sun; Kook, Yoon-Hoh

2017-01-01

Recent multi locus sequence typing (MLST) and genome based studies indicate that lateral gene transfer (LGT) events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas), we applied rpoB typing (711 bp) to 106 Korean strains of M. massiliense infection that had already been identified by hsp65 sequence analysis (603 bp). The analysis indicated 6 smooth strains in M. massiliense Type I (10.0%, 6/60) genotypes but no strains in M. massiliense Type II genotypes (0%, 0/46), showing a discrepancy between the 2 typing methods. Further MLST analysis based on the partial sequencing of seven housekeeping genes, argH, cya, glpK, gnd, murC, pta and purH, as well as erm(41) PCR proved that these 6 Rec-mas strains consisted of two distinct genotypes belonging to M. massiliense and not M. abscessus. The complete rpoB sequencing analysis showed that these 6 Rec-mas strains have an identical hybrid rpoB gene, of which a 478 bp partial rpoB fragment may be laterally transferred from M. abscessus. Notably, five of the 6 Rec-mas strains showed complete identical sequences in a total of nine genes, including the seven MLST genes, hsp65, and rpoB, suggesting their clonal propagation in South Korea. In conclusion, we identified 6 M. massiliense smooth strains of 2 phylogenetically distinct genotypes with a specific hybrid rpoB gene laterally transferred from M. abscessus from Korean patients. Their clinical relevance and bacteriological traits remain to be elucidated. PMID:28604829

Improved thermoelectric property of B-doped Si/Ge multilayered quantum dot films prepared by RF magnetron sputtering

NASA Astrophysics Data System (ADS)

Peng, Ying; Miao, Lei; Li, Chao; Huang, Rong; Urushihara, Daisuke; Asaka, Toru; Nakatsuka, Osamu; Tanemura, Sakae

2018-01-01

The use of nanostructured thermoelectric materials that can effectively reduce the lattice conductivity with minimal effects on electrical properties has been recognized as the most successful approach to decoupling three key parameters (S, σ, and κ) and reaching high a dimensionless figure of merit (ZT) values. Here, five-period multilayer films consisting of 10 nm B-doped Si, 1.1 nm B, and 13 nm B-doped Ge layers in each period were prepared on Si wafer substrates using a magnetron sputtering system. Nanocrystallites of 22 nm diameter were formed by post-annealing at 800 °C in a short time. The nanostructures were confirmed by X-ray diffraction analysis, Raman spectroscopy, and transmission electron microscopy. The maximum Seebeck coefficient of Si/Ge films is significantly increased to 850 µV/K at 200 °C with their electrical resistivity decreased to 1.3 × 10-5 Ω·m, and the maximum power factor increased to 5.6 × 10-2 W·m-1·K-2. The improved thermoelectric properties of Si/Ge nanostructured films are possibly attributable to the synergistic effects of interface scattering, interface barrier, and quantum dot localization.

Collisional Dynamics of the B 3Pi(O+) State of Bromine Monochloride.

DTIC Science & Technology

1986-08-01

many useful discussions on energy transfer studies and continual friendship, to Lt. Brian McFeeters for execution of an RKR program, and to AFWL...2 C. The Halogens and Interhalogens.................... 6 D. The Study of Molecular Energy Transfer............ 9 E. Problem...Matrix.............. 137 8. The BrCl(B) Quenching Mechanism................ 144 9. Energy Transfer with Rare Gases................ 145 10. Summary of

76 FR 51027 - F&B Wood Corporation; Milltown Hydroelectric LLC.; Notice of Transfer of Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-17

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 12629-003] F&B Wood... the Commission's regulations,\\1\\ F&B Wood Corporation, exemptee for the Corriveau Hydroelectric... Project No. 12629 on October 24, 2006. F&B Wood Corp.,117 FERC ] 62,059 (2006) \\3\\ See filings of May 9...

Proton transfer in the K-channel analog of B-type Cytochrome c oxidase from Thermus thermophilus.

PubMed

Woelke, Anna Lena; Wagner, Anke; Galstyan, Gegham; Meyer, Tim; Knapp, Ernst-Walter

2014-11-04

A key enzyme in aerobic metabolism is cytochrome c oxidase (CcO), which catalyzes the reduction of molecular oxygen to water in the mitochondrial and bacterial membranes. Substrate electrons and protons are taken up from different sides of the membrane and protons are pumped across the membrane, thereby generating an electrochemical gradient. The well-studied A-type CcO uses two different entry channels for protons: the D-channel for all pumped and two consumed protons, and the K-channel for the other two consumed protons. In contrast, the B-type CcO uses only a single proton input channel for all consumed and pumped protons. It has the same location as the A-type K-channel (and thus is named the K-channel analog) without sharing any significant sequence homology. In this study, we performed molecular-dynamics simulations and electrostatic calculations to characterize the K-channel analog in terms of its energetic requirements and functionalities. The function of Glu-15B as a proton sink at the channel entrance is demonstrated by its rotational movement out of the channel when it is deprotonated and by its high pKA value when it points inside the channel. Tyr-244 in the middle of the channel is identified as the valve that ensures unidirectional proton transfer, as it moves inside the hydrogen-bond gap of the K-channel analog only while being deprotonated. The electrostatic energy landscape was calculated for all proton-transfer steps in the K-channel analog, which functions via proton-hole transfer. Overall, the K-channel analog has a very stable geometry without large energy barriers.

Proton Transfer in the K-Channel Analog of B-Type Cytochrome c Oxidase from Thermus thermophilus

PubMed Central

Woelke, Anna Lena; Wagner, Anke; Galstyan, Gegham; Meyer, Tim; Knapp, Ernst-Walter

2014-01-01

A key enzyme in aerobic metabolism is cytochrome c oxidase (CcO), which catalyzes the reduction of molecular oxygen to water in the mitochondrial and bacterial membranes. Substrate electrons and protons are taken up from different sides of the membrane and protons are pumped across the membrane, thereby generating an electrochemical gradient. The well-studied A-type CcO uses two different entry channels for protons: the D-channel for all pumped and two consumed protons, and the K-channel for the other two consumed protons. In contrast, the B-type CcO uses only a single proton input channel for all consumed and pumped protons. It has the same location as the A-type K-channel (and thus is named the K-channel analog) without sharing any significant sequence homology. In this study, we performed molecular-dynamics simulations and electrostatic calculations to characterize the K-channel analog in terms of its energetic requirements and functionalities. The function of Glu-15B as a proton sink at the channel entrance is demonstrated by its rotational movement out of the channel when it is deprotonated and by its high pKA value when it points inside the channel. Tyr-244 in the middle of the channel is identified as the valve that ensures unidirectional proton transfer, as it moves inside the hydrogen-bond gap of the K-channel analog only while being deprotonated. The electrostatic energy landscape was calculated for all proton-transfer steps in the K-channel analog, which functions via proton-hole transfer. Overall, the K-channel analog has a very stable geometry without large energy barriers. PMID:25418102

Two-proton pickup studies with the (6Li,8B) reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisenmiller, R.B.

1976-12-03

The (/sup 6/Li,/sup 8/B) reaction has been investigated on targets of /sup 26/Mg, /sup 24/Mg, /sup 16/O, /sup 13/C, /sup 12/C, /sup 11/B, /sup 10/B, and /sup 9/Be at a bombarding energy of 80.0 MeV, and on targets of /sup 16/O, /sup 12/C, /sup 9/Be, /sup 7/Li, and /sup 6/Li at a bombarding energy of 93.3 MeV. Only levels consistent with direct, single-step two-proton pickup reaction mechanisms were observed to be strongly populated. On T/sub z/ = 0 targets, the spectroscopic selectivity of this reaction resembles that of the analogous (p,t) reaction. Additionally, these data demonstrate the dominance of spatiallymore » symmetric transfer of the two protons. On T/sub z/ greater than 0 targets the (/sup 6/Li,/sup 8/B) reaction was employed to locate two previously unreported levels (at 7.47 +- 0.05 MeV and 8.86 +- 0.07 MeV) in the T/sub z/ = 2 nuclide /sup 24/Ne and to establish the low-lying 1p-shell states in the T/sub z/ = /sup 3///sub 2/ nuclei /sup 11/Be, /sup 9/Li, and /sup 7/He. However, no evidence was seen for any narrow levels in the T/sub z/ = /sup 3///sub 2/ nuclide /sup 5/H nor for any narrow excited states in /sup 7/He. The angular distributions reported here are rather featureless and decrease monotonically with increasing angle. This behavior can be shown by a semi-classical reaction theory to be a consequence of the reaction kinematics. A semi-classical approach also suggests that the kinematic term in the transition matrix element is only weakly dependent upon the angular momentum transfer (which is consistent with simple Distorted Wave Born Approximation calculations). However, only qualitative agreement was obtained between the observed relative transition yields and semi-classical predictions, using the two-nucleon coefficients of fractional parentage of Cohen and Kurath, probably due to the limitations of the semi-classical reaction theory.« less

Detection and Quantification of Biologically Active Botulinum Neurotoxin Serotypes A and B Using a Förster Resonance Energy Transfer-Based Quantum Dot Nanobiosensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yun; Fry, H. Christopher; Skinner, Guy E.

Botulinum neurotoxin (BoNT) is the most potent toxin known. The ingestion of food contaminated with biologically active BoNT causes foodborne botulism, which can lead to respiratory paralysis, coma, and death after ingestion of as little as 70 mu g for a 70 kg human. Because of its lethality and challenges associated with current detection methods, there is an urgent need for highly sensitive rapid screening techniques capable of detecting biologically active BoNT. Here, we describe a Forster resonance energy transfer-based nanobiosensor that uses quantum dots (QDs) and two specific quencher-labeled peptide probes to detect and differentiate two biologically active formsmore » of BoNT, serotypes A and B, which were responsible for 80% of human foodborne botulism cases in the U.S. from 2012 to 2015. Each peptide probe contains an enzymatic cleavage site specific to only one serotype. QDs were selected based on the spectral overlap with the quenchers. In the presence of the target BoNT serotype, the peptide probe is cleaved and the quenching of QD photoluminescence (PL) is reduced, giving a signal that is easily detected by a PL spectrophotometer. This sensor performance was evaluated with light chains of BoNT/A and BoNT/B (LcA and LcB), catalytic domains of the respective serotypes. LcA and LcB were detected in 3 h with limits of detection of 0.2 and 2 ng/mL, respectively. The specificity of the sensor was evaluated, and no cross-reactivity from nontarget serotypes was observed with 2 h of incubation. Because each serotype-specific peptide is conjugated to a QD with a unique emission wavelength, multiple biologically active BoNT serotypes could be detected in one PL spectrum. The sensor was also shown to be responsive to BoNT/A and BoNT/B holotoxins. Good performance of this sensor implies its potential application as a rapid screening method for biologically active BoNT/A and BoNT/B in the laboratory and in the field.« less

Evidence for the η(b)(2S) and observation of h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ.

PubMed

Mizuk, R; Asner, D M; Bondar, A; Pedlar, T K; Adachi, I; Aihara, H; Arinstein, K; Aulchenko, V; Aushev, T; Aziz, T; Bakich, A M; Bay, A; Belous, K; Bhardwaj, V; Bhuyan, B; Bischofberger, M; Bonvicini, G; Bozek, A; Bračko, M; Brodzicka, J; Browder, T E; Chekelian, V; Chen, A; Chen, P; Cheon, B G; Chilikin, K; Chistov, R; Cho, I-S; Cho, K; Choi, S-K; Choi, Y; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Eidelman, S; Epifanov, D; Fast, J E; Gaur, V; Gabyshev, N; Garmash, A; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Horii, Y; Hoshi, Y; Hou, W-S; Hsiung, Y B; Hyun, H J; Iijima, T; Ishikawa, A; Itoh, R; Iwabuchi, M; Iwasaki, Y; Iwashita, T; Jaegle, I; Julius, T; Kang, J H; Kapusta, P; Kawasaki, T; Kim, H J; Kim, H O; Kim, J H; Kim, K T; Kim, M J; Kim, Y J; Kinoshita, K; Ko, B R; Koblitz, S; Kodyš, P; Korpar, S; Kouzes, R T; Križan, P; Krokovny, P; Kuhr, T; Kumita, T; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, S-H; Li, J; Libby, J; Liu, C; Liu, Y; Liu, Z Q; Liventsev, D; Louvot, R; Matvienko, D; McOnie, S; Miyabayashi, K; Miyata, H; Mohanty, G B; Mohapatra, D; Moll, A; Muramatsu, N; Mussa, R; Nakao, M; Natkaniec, Z; Ng, C; Nishida, S; Nishimura, K; Nitoh, O; Nozaki, T; Ohshima, T; Okuno, S; Olsen, S L; Onuki, Y; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Pestotnik, R; Petrič, M; Piilonen, L E; Poluektov, A; Röhrken, M; Sakai, Y; Sandilya, S; Santel, D; Sanuki, T; Sato, Y; Schneider, O; Schwanda, C; Senyo, K; Seon, O; Sevior, M E; Shapkin, M; Shen, C P; Shibata, T-A; Shiu, J-G; Shwartz, B; Sibidanov, A; Simon, F; Smerkol, P; Sohn, Y-S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Sumihama, M; Sumiyoshi, T; Tanida, K; Tatishvili, G; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Tsuboyama, T; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Vanhoefer, P; Varner, G; Varvell, K E; Vinokurova, A; Vorobyev, V; Wang, C H; Wang, M-Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yabsley, B D; Yamaoka, J; Yamashita, Y; Yuan, C Z; Zhang, Z P; Zhilich, V

2012-12-07

We report the first evidence for the η(b)(2S) using the h(b)(2P)→η(b)(2S)γ transition and the first observation of the h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ transitions. The mass and width of the η(b)(1S) and η(b)(2S) are measured to be m(η(b)(1S))=(9402.4±1.5±1.8) MeV/c(2), m(η(b)(2S))=(9999.0±3.5(-1.9)(+2.8)) MeV/c(2), and Γ(η(b)(1S))=(10.8(-3.7-2.0)(+4.0+4.5)) MeV. We also update the h(b)(1P) and h(b)(2P) mass measurements. We use a 133.4 fb(-1) data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Interaction of amphotericin B and its low toxic derivative, N-methyl-N-D-fructosyl amphotericin B methyl ester, with fungal, mammalian and bacterial cells measured by the energy transfer method.

PubMed

Szlinder-Richert, Joanna; Cybulska, Barbara; Grzybowska, Jolanta; Bolard, Jacques; Borowski, Edward

2004-04-01

Amphotericin B (AMB) derivative, N-methyl-N-D-fructosyl amphotericin B methyl ester (MFAME) retains the broad antifungal spectrum and potency of the parent antibiotic, whereas its toxicity towards mammalian cells is reduced by about two orders of magnitude. The purpose of this work was to find out whether the differences observed in the toxicity of MFAME and native AMB are due to the differential drugs affinity to fungal and mammalian cell membranes. Comparative studies on AMB and MFAME biological activity and their affinity to fungal, mammalian and bacterial cells were performed. The interaction of AMB and MFAME with cells have been studied by fluorescence method based on the energy transfer between membrane fluorescent probe (donor) and the polyenic chromophore of the antibiotic (acceptor) simultaneously present in the cell membrane. The amount of the antibiotic bound to cells was indicated by the extent of fluorescence quenching of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) or 1,6-diphenyl-1,3,5-hexatriene (DPH) by polyenic chromophore of the antibiotic. The results obtained indicate that binding extent and characteristics for both antibiotics are comparable in the three types of cells studied. Dramatically lower toxicity of MFAME as compared to AMB towards mammalian cells is not related to the antibiotic-cell affinity, but rather to different consequences of these interactions for cells, reflected in membrane permeabilization. MFAME is definitely less effective than parent AMB in the permeabilizing species formation in mammalian cell membrane.

Femtosecond spectroscopy of native and carotenoidless purple-bacterial LH2 clarifies functions of carotenoids.

PubMed

Theiss, Christoph; Leupold, Dieter; Moskalenko, Andrei A; Razjivin, Andrei P; Eichler, Hans J; Lokstein, Heiko

2008-06-01

EET between the two circular bacteriochlorophyll compartments B800 and B850 in native (containing the carotenoid rhodopin) and carotenoidless LH2 isolated from the photosynthetic purple sulfur bacterium Allochromatium minutissimum was investigated by femtosecond time-resolved transient absorption spectroscopy. Both samples were excited with 120-fs laser pulses at 800 nm, and spectral evolution was followed in the 720-955 nm range at different delay times. No dependence of transient absorption in the B800 band on the presence of the carotenoid rhodopin was found. Together with the likewise virtually unchanged absorption spectra in the bacteriochlorophyll Q(y) region, these observations suggest that absence of rhodopin does not significantly alter the structure of the pigment-protein complex including interactions between bacteriochlorophylls. Apparently, rhodopin does also not accelerate B800 to B850 EET in LH2, contrary to what has been suggested previously. Moreover, "carotenoid-catalyzed internal conversion" can also be excluded for the bacteriochlorophylls in LH2 of A. minutissimum. Together with previous results obtained with two-photon fluorescence excitation spectroscopy, it can also be concluded that there is neither EET from rhodopin to B800 nor (back-)EET from B800 to rhodopin.

31 CFR 800.204 - Control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Control. 800.204 Section 800.204... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in situations...

Species differences in unlocking B-side electron transfer in bacterial reaction centers

DOE PAGES

Dylla, Nicholas P.; Faries, Kaitlyn M.; Wyllie, Ryan M.; ...

2016-06-21

The structure of the bacterial photosynthetic reaction center (RC) reveals symmetry-related electron transfer (ET) pathways, but only one path is used in native RCs. Analogous mutations have been made in two Rhodobacter (R.) species. A glutamic acid at position 133 in the M subunit increases transmembrane charge separation via the naturally inactive (B-side) path through impacts on primary ET in mutant R. sphaeroidesRCs. Prior work showed that the analogous substitution in the R. capsulatusRC also increases B-side activity, but mainly affects secondary ET. Finally, the overall yields of transmembrane ET are similar, but enabled in fundamentally different ways.

Species differences in unlocking B-side electron transfer in bacterial reaction centers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dylla, Nicholas P.; Faries, Kaitlyn M.; Wyllie, Ryan M.

The structure of the bacterial photosynthetic reaction center (RC) reveals symmetry-related electron transfer (ET) pathways, but only one path is used in native RCs. Analogous mutations have been made in two Rhodobacter (R.) species. A glutamic acid at position 133 in the M subunit increases transmembrane charge separation via the naturally inactive (B-side) path through impacts on primary ET in mutant R. sphaeroidesRCs. Prior work showed that the analogous substitution in the R. capsulatusRC also increases B-side activity, but mainly affects secondary ET. Finally, the overall yields of transmembrane ET are similar, but enabled in fundamentally different ways.

31 CFR 800.204 - Control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Control. 800.204 Section 800.204 Money... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in situations...

31 CFR 800.204 - Control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Control. 800.204 Section 800.204 Money... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in situations...

31 CFR 800.204 - Control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Control. 800.204 Section 800.204 Money... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in situations...

31 CFR 800.204 - Control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Control. 800.204 Section 800.204 Money... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in situations...

The transfer of natural Rhodamine B contamination from raw paprika fruit to capsicum oleoresin during the extraction process.

PubMed

Wu, Naiying; Gao, Wei; Lian, Yunhe; Du, Jingjing; Tie, Xiaowei

2017-12-15

Occurrence of Rhodamine B (RhB) contamination in paprika caused by agricultural materials during the vegetation process has been reported. It may transfer during the process of active compounds extraction, and eventually exist in final products. Herein, the re-distribution of RhB during the extraction process was assessed in terms of RhB contents, as well as mass, color value and capsaicinoids yield of each process. Results revealed that natural RhB contamination at 0.55-1.11µg/kg originated from raw paprika fruit then transferred with the extraction proceeded. About 95.5% of RhB was found in red oleoresin. After separation of red oleoresin, 91.6% of RhB was remained in capsicum oleoresin, only 3.7% in paprika red. These results were consistent with total capsaicinoids recovery of each product. The RhB levels in edible capsicum oleoresin in our present study at 0.01-0.34µg/kg did not exceed the legal limits established by the European Union. Copyright © 2017 Elsevier Ltd. All rights reserved.

Resonant electronic excitation energy transfer by exchange mechanism in the quantum dot system

NASA Astrophysics Data System (ADS)

Chikalova-Luzina, O. P.; Samosvat, D. M.; Vyatkin, V. M.; Zegrya, G. G.

2017-11-01

A microscopic theory of nonradiative resonance energy transfer between spherical A3B5 semiconductor quantum dots by the exchange mechanism is suggested. The interdot Coulomb interaction is taken into consideration. It is assumed that the quantum dot-donor and the quantum dot-acceptor are made from the same A3B5 compound and are embedded in the matrix of another material that produces potential barriers for electrons and holes. The dependences of the energy transfer rate on the quantum-dot system parameters are found in the frame of the Kane model that provides the most adequate description of the real spectra of A3B5 semiconductors. The analytical treatment is carried out with using the density matrix method, which enabled us to perform an energy transfer analysis both in the weak-interaction approximation and in the strong-interaction approximation. The numerical calculations showed the saturation of the energy transfer rate at the distances between the donor and the acceptor approaching the contact one. The contributions of the exchange and direct Coulomb intractions can be of the same order at the small distances and can have the same value in the saturation range.

10 CFR 850.20 - Baseline beryllium inventory.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Baseline beryllium inventory. 850.20 Section 850.20 Energy... Baseline beryllium inventory. (a) The responsible employer must develop a baseline inventory of the locations of beryllium operations and other locations of potential beryllium contamination, and identify the...

Luminescence and energy transfer of Tb3+-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses.

PubMed

Zuo, Chenggang; Huang, Jinze; Liu, Shaoyou; Xiao, Anguo; Shen, Youming; Zhang, Xiangyang; Zhou, Zhihua; Zhu, Ligang

2017-12-05

Transparent Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses with the greater than 4g/cm 3 were prepared by high temperature melting method and its luminescent properties have been investigated by measured UV-vis transmission, excitation, emission and luminescence decay spectra. The transmission spectrum shows there are three weak absorption bands locate at about 312, 378 and 484nm in the glasses and it has good transmittance in the visible spectrum region. Intense green emission can be observed under UV excitation. The effective energy transfer from Gd 3+ ion to Tb 3+ ion could occur and sensitize the luminescence of Tb 3+ ion. The green emission intensity of Tb 3+ ion could change with the increasing SiO 2 /B 2 O 3 ratio in the borosilicate glass matrix. With the increasing concentration of Tb 3+ ion, 5 D 4 → 7 F J transitions could be enhanced through the cross relaxation between the two nearby Tb 3+ ions. Luminescence decay time of 2.12ms from 546nm emission is obtained. The results indicate that Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses would be potential scintillating material for applications in X-ray imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

10 CFR 850.10 - Development and approval of the CBDPP.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Development and approval of the CBDPP. 850.10 Section 850.10 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Administrative Requirements § 850.10 Development and approval of the CBDPP. (a) Preparation and submission of initial CBDPP to...

10 CFR 850.10 - Development and approval of the CBDPP.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Development and approval of the CBDPP. 850.10 Section 850.10 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Administrative Requirements § 850.10 Development and approval of the CBDPP. (a) Preparation and submission of initial CBDPP to...

Getting the message across: principles for developing brief-Knowledge Transfer (b-KT) communiqués.

PubMed

Shaw, Lynn

2012-01-01

This feature article on knowledge transfer presents principles and strategies to support the development of short communiqués to end-users. Formal and informal knowledge brokers are the targeted users of the strategies. Research studies and conceptual literature in knowledge transfer informed the development of brief-Knowledge Transfer (b-KT) principles. Principles are explained and a sample of how they informed the development of KIT-Tip Sheets is offered to promote ways to use principles in knowledge dissemination. b-KT principles can be used as a framework to guide the development of short communiqués by knowledge brokers in work practice but also in the health, social and rehabilitation domains. In addition, these principles promote the participation of end-users in the development of knowledge transfer. Formal evaluation is needed on the use of these principles in achieving the uptake and use of knowledge by end-users.

Epstein-Barr Virus Infection of Polarized Epithelial Cells via the Basolateral Surface by Memory B Cell-Mediated Transfer Infection

PubMed Central

Shannon-Lowe, Claire; Rowe, Martin

2011-01-01

Epstein Barr virus (EBV) exhibits a distinct tropism for both B cells and epithelial cells. The virus persists as a latent infection of memory B cells in healthy individuals, but a role for infection of normal epithelial is also likely. Infection of B cells is initiated by the interaction of the major EBV glycoprotein gp350 with CD21 on the B cell surface. Fusion is triggered by the interaction of the EBV glycoprotein, gp42 with HLA class II, and is thereafter mediated by the core fusion complex, gH/gL/gp42. In contrast, direct infection of CD21-negative epithelial cells is inefficient, but efficient infection can be achieved by a process called transfer infection. In this study, we characterise the molecular interactions involved in the three stages of transfer infection of epithelial cells: (i) CD21-mediated co-capping of EBV and integrins on B cells, and activation of the adhesion molecules, (ii) conjugate formation between EBV-loaded B cells and epithelial cells via the capped adhesion molecules, and (iii) interaction of EBV glycoproteins with epithelial cells, with subsequent fusion and uptake of virions. Infection of epithelial cells required the EBV gH and gL glycoproteins, but not gp42. Using an in vitro model of normal polarized epithelia, we demonstrated that polarization of the EBV receptor(s) and adhesion molecules restricted transfer infection to the basolateral surface. Furthermore, the adhesions between EBV-loaded B cells and the basolateral surface of epithelial cells included CD11b on the B cell interacting with heparan sulphate moieties of CD44v3 and LEEP-CAM on epithelial cells. Consequently, transfer infection was efficiently mediated via CD11b-positive memory B cells but not by CD11b–negative naïve B cells. Together, these findings have important implications for understanding the mechanisms of EBV infection of normal and pre-malignant epithelial cells in vivo. PMID:21573183

10 CFR 850.37 - Training and counseling.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Training and counseling. 850.37 Section 850.37 Energy... Training and counseling. (a) The responsible employer must develop and implement a beryllium training... implement a counseling program to assist beryllium-associated workers who are diagnosed by the SOMD to be...

10 CFR 850.37 - Training and counseling.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Training and counseling. 850.37 Section 850.37 Energy... Training and counseling. (a) The responsible employer must develop and implement a beryllium training... implement a counseling program to assist beryllium-associated workers who are diagnosed by the SOMD to be...

10 CFR 850.37 - Training and counseling.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Training and counseling. 850.37 Section 850.37 Energy... Training and counseling. (a) The responsible employer must develop and implement a beryllium training... implement a counseling program to assist beryllium-associated workers who are diagnosed by the SOMD to be...

10 CFR 850.37 - Training and counseling.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Training and counseling. 850.37 Section 850.37 Energy... Training and counseling. (a) The responsible employer must develop and implement a beryllium training... implement a counseling program to assist beryllium-associated workers who are diagnosed by the SOMD to be...

10 CFR 850.37 - Training and counseling.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Training and counseling. 850.37 Section 850.37 Energy... Training and counseling. (a) The responsible employer must develop and implement a beryllium training... implement a counseling program to assist beryllium-associated workers who are diagnosed by the SOMD to be...

20 CFR 638.800 - Program management.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Program management. 638.800 Section 638.800... TITLE IV-B OF THE JOB TRAINING PARTNERSHIP ACT Administrative Provisions § 638.800 Program management. (a) The Job Corps Director shall establish and use internal program management procedures sufficient...

20 CFR 638.800 - Program management.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Program management. 638.800 Section 638.800... TITLE IV-B OF THE JOB TRAINING PARTNERSHIP ACT Administrative Provisions § 638.800 Program management. (a) The Job Corps Director shall establish and use internal program management procedures sufficient...

20 CFR 638.800 - Program management.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Program management. 638.800 Section 638.800... TITLE IV-B OF THE JOB TRAINING PARTNERSHIP ACT Administrative Provisions § 638.800 Program management. (a) The Job Corps Director shall establish and use internal program management procedures sufficient...

Charm-beauty meson bound states from B (B*)D (D*) and B (B*)D \\xAF(D\\xAF*) interaction

NASA Astrophysics Data System (ADS)

Sakai, S.; Roca, L.; Oset, E.

2017-09-01

We evaluate the s -wave interaction of pseudoscalar and vector mesons with both charm and beauty to investigate the possible existence of molecular B D , B*D , B D*, B*D*, B D ¯, B*D ¯, B D¯*, or B*D¯* meson states. The scattering amplitude is obtained implementing unitarity starting from a tree level potential accounting for the dominant vector meson exchange. The diagrams are evaluated using suitable extensions to the heavy flavor sector of the hidden gauge symmetry Lagrangians involving vector and pseudoscalar mesons, respecting heavy quark spin symmetry. We obtain bound states at energies above 7 GeV for B D (JP=0+), B*D (1+), B D* (1+), and B*D* (0+, 1+, 2+), all in isospin 0. For B D ¯ (0+), B*D ¯ (1+), B D¯* (1+), and B*D¯* (0+, 1+, 2+) we also find similar bound states in I =0 , but much less bound, which would correspond to exotic meson states with b ¯ and c ¯ quarks, and for the I =1 we find a repulsive interaction. We also evaluate the scattering lengths in all cases, which can be tested in current investigations of lattice QCD.

Hygromycin B phosphotransferase as a selectable marker for DNA transfer experiments with higher eucaryotic cells.

PubMed

Blochlinger, K; Diggelmann, H

1984-12-01

The DNA coding sequence for the hygromycin B phosphotransferase gene was placed under the control of the regulatory sequences of a cloned long terminal repeat of Moloney sarcoma virus. This construction allowed direct selection for hygromycin B resistance after transfection of eucaryotic cell lines not naturally resistant to this antibiotic, thus providing another dominant marker for DNA transfer in eucaryotic cells.

8B + 208Pb Elastic Scattering at Coulomb Barrier Energies

NASA Astrophysics Data System (ADS)

La Commara, M.; Mazzocco, M.; Boiano, A.; Boiano, C.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Signorini, C.; Strano, E.; Torresi, D.; Yamaguchi, H.; Kahl, D.; Di Meo, P.; Grebosz, J.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Iwasa, N.; Jeong, S. C.; Jia, H. M.; Kim, Y. H.; Kimura, S.; Kubono, S.; Lin, C. J.; Miyatake, H.; Mukai, M.; Nakao, T.; Nicoletto, M.; Sakaguchi, Y.; Sánchez-Benítez, A. M.; Soramel, F.; Teranishi, T.; Wakabayashi, Y.; Watanabe, Y. X.; Yang, L.; Yang, Y. Y.

2018-02-01

The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (Sp = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.

8B + 208Pb Elastic Scattering at Coulomb Barrier Energies

NASA Astrophysics Data System (ADS)

La Commara, M.; Mazzocco, M.; Boiano, A.; Boiano, C.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Signorini, C.; Strano, E.; Torresi, D.; Yamaguchi, H.; Kahl, D.; Di Meo, P.; Grebosz, J.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Iwasa, N.; Jeong, S. C.; Jia, H. M.; Kim, Y. H.; Kimura, S.; Kubono, S.; Lin, C. J.; Miyatake, H.; Mukai, M.; Nakao, T.; Nicoletto, M.; Sakaguchi, Y.; Sánchez-Benítez, A. M.; Soramel, F.; Teranishi, T.; Wakabayashi, Y.; Watanabe, Y. X.; Yang, L.; Yang, Y. Y.

2017-11-01

The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (S p = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.

Single-molecule spectroscopy reveals that individual low-light LH2 complexes from Rhodopseudomonas palustris 2.1.6. have a heterogeneous polypeptide composition.

PubMed

Brotosudarmo, Tatas H P; Kunz, Ralf; Böhm, Paul; Gardiner, Alastair T; Moulisová, Vladimíra; Cogdell, Richard J; Köhler, Jürgen

2009-09-02

Rhodopseudomonas palustris belongs to the group of purple bacteria that have the ability to produce LH2 complexes with unusual absorption spectra when they are grown at low-light intensity. This ability is often related to the presence of multiple genes encoding the antenna apoproteins. Here we report, for the first time to our knowledge, direct evidence that individual low-light LH2 complexes have a heterogeneous alphabeta-apoprotein composition that modulates the site energies of Bchl a molecules, producing absorption bands at 800, 820, and 850 nm. The arrangement of the Bchl a molecules in the "tightly coupled ring" can be modeled by nine alphabeta-Bchls dimers, such that the Bchls bound to six alphabeta-pairs have B820-like site energies and the remaining Bchl a molecules have B850-like site energies. Furthermore, the experimental data can only be satisfactorily modeled when these six alphabeta-pairs with B820 Bchl a molecules are distributed such that the symmetry of the assembly is reduced to C(3). It is also clear from the measured single-molecule spectra that the energies of the electronically excited states in the mixed B820/850 ring are mainly influenced by diagonal disorder.

Energy barrier analysis of Nd-Fe-B thin films

NASA Astrophysics Data System (ADS)

Goto, R.; Okamoto, S.; Kikuchi, N.; Kitakami, O.

2015-05-01

The magnetization reversal mechanism of a permanent magnet has long been a controversial issue, which is closely related to the so-called coercivity problem. It is well known that the energy barrier for magnetization reversal contains essential information on reversal process. In this study, we propose a method to analyze the energy barrier function for the magnetization reversal. Preferentially (001) oriented Nd-Fe-B films with and without a Nd overlayer are used as model magnets. By combining the magnetic viscosity and time dependent coercivity measurements, the barrier function has been successfully evaluated. As a result, although the Nd-Fe-B films with and without Nd overlayer exhibit different magnetic behaviors, the power indices for their energy barrier are almost the same, suggesting that the magnetization reversal proceeds in a similar mode.

Functional Features of TonB Energy Transduction Systems of Acinetobacter baumannii

PubMed Central

Zimbler, Daniel L.; Arivett, Brock A.; Beckett, Amber C.; Menke, Sharon M.

2013-01-01

Acinetobacter baumannii is an opportunistic pathogen that causes severe nosocomial infections. Strain ATCC 19606T utilizes the siderophore acinetobactin to acquire iron under iron-limiting conditions encountered in the host. Accordingly, the genome of this strain has three tonB genes encoding proteins for energy transduction functions needed for the active transport of nutrients, including iron, through the outer membrane. Phylogenetic analysis indicates that these tonB genes, which are present in the genomes of all sequenced A. baumannii strains, were acquired from different sources. Two of these genes occur as components of tonB-exbB-exbD operons and one as a monocistronic copy; all are actively transcribed in ATCC 19606T. The abilities of components of these TonB systems to complement the growth defect of Escherichia coli W3110 mutants KP1344 (tonB) and RA1051 (exbBD) under iron-chelated conditions further support the roles of these TonB systems in iron acquisition. Mutagenesis analysis of ATCC 19606T tonB1 (subscripted numbers represent different copies of genes or proteins) and tonB2 supports this hypothesis: their inactivation results in growth defects in iron-chelated media, without affecting acinetobactin biosynthesis or the production of the acinetobactin outer membrane receptor protein BauA. In vivo assays using Galleria mellonella show that each TonB protein is involved in, but not essential for, bacterial virulence in this infection model. Furthermore, we observed that TonB2 plays a role in the ability of bacteria to bind to fibronectin and to adhere to A549 cells by uncharacterized mechanisms. Taken together, these results indicate that A. baumannii ATCC 19606T produces three independent TonB proteins, which appear to provide the energy-transducing functions needed for iron acquisition and cellular processes that play a role in the virulence of this pathogen. PMID:23817614

DFT study on the isomerization and tautomerism in vitamins B3 (niacin), B5 (pantothenic acid) and B7 (biotin)

NASA Astrophysics Data System (ADS)

Valadbeigi, Younes; Farrokhpour, Hossein; Tabrizchi, Mahmoud

2014-05-01

Isomerization and tautomerism of the three water soluble vitamins including B3, B5 and B7 were studied applying density functional theory using B3LYP method in gas and aqueous phases. Activation energies (Ea), Gibbs free energies of activation (ΔG#), and imaginary frequencies of the transition state structures were calculated for all the isomerization and tautomerism reactions. Activation energies of the neutral → zwitterion (amine-enamine) tautomerism in vitamin B3 were 310-360 kJ/mol where these values for the keto-enol tautomerism were 100-130 kJ/mol. It was found that water molecule catalyzes the tautomerism and decreases the activation energies about 90-160 kJ/mol.

Adoptive transfer of nontransgenic mesenteric lymph node cells induces colitis in athymic HLA-B27 transgenic nude rats

PubMed Central

Hoentjen, F; Tonkonogy, S L; Liu, B; Sartor, R B; Taurog, J D; Dieleman, L A

2006-01-01

HLA-B27 transgenic (TG) rats develop spontaneous colitis when colonized with intestinal bacteria, whereas athymic nude (rnu/rnu) HLA-B27 TG rats remain disease free. The present study was designed to determine whether or not HLA-B27 expression on T cells is required for development of colitis after transfer of mesenteric lymph node (MLN) cells into rnu/rnu HLA-B27 recipients. Athymic nontransgenic (non-TG) and HLA-B27 TG recipients received MLN cells from either TG or non-TG rnu/+ heterozygous donor rats that contain T cells. HLA-B27 TG rnu/rnu recipients receiving either non-TG or TG MLN cells developed severe colitis and had higher caecal MPO and IL-1β levels, and their MLN cells produced more IFN-γ and less IL-10 after in vitro stimulation with caecal bacterial lysate compared to rnu/rnu non-TG recipients that remained disease free after receiving either TG or non-TG cells. Interestingly, proliferating donor TG T cells were detectable one week after adoptive transfer into rnu/rnu TG recipients but not after transfer into non-TG recipients. T cells from either non-TG or TG donors induce colitis in rnu/rnu TG but not in non-TG rats, suggesting that activation of effector T cells by other cell types that express HLA-B27 is pivotal for the pathogenesis of colitis in this model. PMID:16487247

Low energy measurements of the 10B(p ,α )7Be reaction

NASA Astrophysics Data System (ADS)

Wiescher, M.; deBoer, R. J.; Görres, J.; Azuma, R. E.

2017-04-01

Background: The 11B(p,2 α ) 4He reaction is being discussed as a prime candidate for advanced aneutronic fusion fuel systems. Particular interest in this reaction has recently emerged for laser driven plasma systems for energy generation and jet-propulsion systems. The lack of long-lived radioactive reaction products has been suggested as the main advantage of proton-boron fusion fuel. However, 19% of natural boron is 10B, with the 10B(p ,α )7Be fusion reaction producing long-lived 7Be as a side product. Purpose: A detailed measurement of the 10B(p ,α )7Be reaction over the critical energy range of hot fusion plasma environments will help to determine the amount of 7Be radioactivity being produced. This information can be used in turn to monitor the actual fusion temperature by offline measurement of the extracted 7Be activity. The goal of the here presented experiment is to expand on the results of earlier experiments, covering a wider energy range of interest for aneutronic plasma fusion applications, including also both 10B(p ,α0)7Be and the 10B(p ,α1)7Be reaction channels. Method: The reaction cross section was measured over a wide energy range from Ep=400 to 1000 keV using particle detection and from Ep=80 to 1440 keV using γ -ray spectroscopic techniques. Reaction α particles were measured at different angles to obtain angular distribution information. The results are discussed in terms of an R -matrix analysis. Results: The cross section data cover a wider energy range than previously investigated and bridge a gap in the previously available data sets. The cross sections show good agreement with previous results in the low energy region and show that the 10B(p ,α0)7Be channel is considerably larger than that of the 10B(p ,α1)7Be channel up to Ep≈1 MeV . Conclusions: The new reaction data provides important new information about the reaction cross section over the entire energy range of plasma fusion facilities. This data, when coupled with

Interfacial hydration, dynamics and electron transfer: multi-scale ET modeling of the transient [myoglobin, cytochrome b5] complex.

PubMed

Keinan, Shahar; Nocek, Judith M; Hoffman, Brian M; Beratan, David N

2012-10-28

Formation of a transient [myoglobin (Mb), cytochrome b(5) (cyt b(5))] complex is required for the reductive repair of inactive ferri-Mb to its functional ferro-Mb state. The [Mb, cyt b(5)] complex exhibits dynamic docking (DD), with its cyt b(5) partner in rapid exchange at multiple sites on the Mb surface. A triple mutant (Mb(3M)) was designed as part of efforts to shift the electron-transfer process to the simple docking (SD) regime, in which reactive binding occurs at a restricted, reactive region on the Mb surface that dominates the docked ensemble. An electrostatically-guided brownian dynamics (BD) docking protocol was used to generate an initial ensemble of reactive configurations of the complex between unrelaxed partners. This ensemble samples a broad and diverse array of heme-heme distances and orientations. These configurations seeded all-atom constrained molecular dynamics simulations (MD) to generate relaxed complexes for the calculation of electron tunneling matrix elements (T(DA)) through tunneling-pathway analysis. This procedure for generating an ensemble of relaxed complexes combines the ability of BD calculations to sample the large variety of available conformations and interprotein distances, with the ability of MD to generate the atomic level information, especially regarding the structure of water molecules at the protein-protein interface, that defines electron-tunneling pathways. We used the calculated T(DA) values to compute ET rates for the [Mb(wt), cyt b(5)] complex and for the complex with a mutant that has a binding free energy strengthened by three D/E → K charge-reversal mutations, [Mb(3M), cyt b(5)]. The calculated rate constants are in agreement with the measured values, and the mutant complex ensemble has many more geometries with higher T(DA) values than does the wild-type Mb complex. Interestingly, water plays a double role in this electron-transfer system, lowering the tunneling barrier as well as inducing protein interface

Investigation of energy transfer mechanisms between Bi(2+) and Tm(3+) by time-resolved spectrum.

PubMed

Li, Yang; Sharafudeen, Kaniyarakkal; Dong, Guoping; Ma, Zhijun; Qiu, Jianrong

2013-11-01

Here, we report for the first time the optical properties of Bi(2+) and Tm(3+) co-doped germanate glasses and elucidate the potential of this material as substrates to improve the performance of CdTe solar cell. A strong emission peak at 800nm is observed under the excitation of 450-700nm in this material. The energy transfer processes from the transitions of Bi(2+) [(2)P3/2(1)→(2)P1/2]: Tm(3+) [(3)H6→(3)H4] are investigated by time-resolved luminescence spectroscopy. A cover glass exhibiting an ultra-broadband response spectrum covering the entire solar visible wavelength region is suggested to enhance the conversion efficiency of CdTe solar cells significantly. Copyright © 2013 Elsevier B.V. All rights reserved.

10 CFR 850.29 - Protective clothing and equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

....132, Personal Protective Equipment General Requirements, when workers use personal protective clothing... 10 Energy 4 2010-01-01 2010-01-01 false Protective clothing and equipment. 850.29 Section 850.29... § 850.29 Protective clothing and equipment. (a) The responsible employer must provide protective...

10 CFR 850.29 - Protective clothing and equipment.

Code of Federal Regulations, 2011 CFR

2011-01-01

....132, Personal Protective Equipment General Requirements, when workers use personal protective clothing... 10 Energy 4 2011-01-01 2011-01-01 false Protective clothing and equipment. 850.29 Section 850.29... § 850.29 Protective clothing and equipment. (a) The responsible employer must provide protective...

Hygromycin B phosphotransferase as a selectable marker for DNA transfer experiments with higher eucaryotic cells.

PubMed Central

Blochlinger, K; Diggelmann, H

1984-01-01

The DNA coding sequence for the hygromycin B phosphotransferase gene was placed under the control of the regulatory sequences of a cloned long terminal repeat of Moloney sarcoma virus. This construction allowed direct selection for hygromycin B resistance after transfection of eucaryotic cell lines not naturally resistant to this antibiotic, thus providing another dominant marker for DNA transfer in eucaryotic cells. Images PMID:6098829

Immunobiologic effects of cytokine gene transfer of the B16-BL6 melanoma.

PubMed

Strome, S E; Krauss, J C; Cameron, M J; Forslund, K; Shu, S; Chang, A E

1993-12-01

The genetic modification of tumors offers an approach to modulate the host immune response to relatively weak native tumor antigens. We examined the immunobiologic effects of various cytokine genes transferred into the poorly immunogenic B16-BL6 murine melanoma. Retroviral expression vectors containing cDNAs for interleukin 2, interleukin 4, interferon gamma, or a neomycin-resistant control were electroporated into a B16-BL6 tumor clone. Selected transfected clones were examined for in vitro cytokine secretion and in vivo tumorigenicity. When cells from individual clones were injected intradermally into syngeneic mice, the interleukin 4-secreting clone grew significantly slower than did the neomycin-resistant transfected control, while the growth of the interleukin 2- and interferon gamma-expressing clones was not affected. Despite minimal cytokine secretion by interferon gamma-transfected cells, these cells expressed upregulated major histocompatibility class I antigen and were more susceptible to lysis by allosensitized cytotoxic T lymphocytes compared with parental or neomycin-resistant transfected tumor targets. We observed diverse immunobiologic effects associated with cytokine gene transfer into the B16-BL6 melanoma. Interleukin 4 transfection of tumor resulted in decreased in vivo tumorigenicity that may be related to a host immune response. Further studies to evaluate the host T-cell response to these gene-modified tumors are being investigated.

Exosome-mediated transfer of miR-10b promotes cell invasion in breast cancer.

PubMed

Singh, Ramesh; Pochampally, Radhika; Watabe, Kounosuke; Lu, Zhaohui; Mo, Yin-Yuan

2014-11-26

Exosomes are 30-100 nm membrane vesicles of endocytic origin, mediating diverse biological functions including tumor cell invasion, cell-cell communication and antigen presentation through transfer of proteins, mRNAs and microRNAs. Recent evidence suggests that microRNAs can be released through ceramide-dependent secretory machinery regulated by neutral sphingomyelinase 2 (nSMase2) enzyme encoded by the smpd3 gene that triggers exosome secretion. However, whether exosome-mediated microRNA transfer plays any role in cell invasion remains poorly understood. Thus, the aim of this study was to identify the exosomal microRNAs involved in breast cancer invasion. The expression level of endogenous and exosomal miRNAs were examined by real time PCR and the expression level of target proteins were detected by western blot. Scanning electron and confocal microscopy were used to characterize exosomes and to study its uptake and transfer. Luciferase reporter plasmids and its mutant were used to confirm direct targeting. Furthermore, the functional significance of exosomal miR-10b was estimated by invasion assay. In this study, we demonstrate that microRNA carrying exosomes can be transferred among different cell lines through direct uptake. miR-10b is highly expressed in metastatic breast cancer MDA-MB-231 cells as compared to non-metastatic breast cancer cells or non-malignant breast cells; it is actively secreted into medium via exosomes. In particular, nSMase2 or ceramide promotes the exosome-mediated miR-10b secretion whereas ceramide inhibitor suppresses this secretion. Moreover, upon uptake, miR-10b can suppress the protein level of its target genes such as HOXD10 and KLF4, indicating its functional significance. Finally, treatment with exosomes derived from MDA-MB-231 cells could induce the invasion ability of non-malignant HMLE cells. Together, our results suggest that a set of specific microRNAs may play an important role in modulating tumor microenvironment through

Submicron R{sub 2}Fe{sub 14}B particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koylu-Alkan, O., E-mail: ozlem@udel.edu, E-mail: hadji@udel.edu; Hadjipanayis, G. C., E-mail: ozlem@udel.edu, E-mail: hadji@udel.edu; Barandiaran, J. M.

Mechanochemical synthesis of submicron R{sub 2}Fe{sub 14}B particles with R = Dy, Nd, Pr has been performed successfully via high energy ball milling of rare-earth oxides, iron oxide and boron oxide in the presence of a reducing agent (Ca) and a dispersant material (CaO), followed by annealing at 800 - 900 °C. In the R = Nd system, we were able to fabricate particles embedded in a CaO matrix with coercivity (H{sub c}) of 10.3 kOe after annealing at 900 °C for 5 min. After washing off the dispersant, the H{sub c} was decreased to below 1 kOe because of hydrogen absorptionmore » that leads to the formation of the hydrated R{sub 2}Fe{sub 14}BH{sub x} phase that has a lower anisotropy. Upon removal of the hydrogen the coercivity was increased to 3.3 kOe. The average size of the Nd{sub 2}Fe{sub 14}B particles increases from 100 nm in a sample synthesized at 800 °C to 158 nm at 900 °C. The isotropic Dy{sub 2}Fe{sub 14}B particles showed a higher coercivity of 21 kOe in washed samples after annealing at 900 °C for 5 min. An average size of 71 nm is measured in samples synthesized at 800 °C and 107 nm at 900 °C. Fitting the high field M(H) measurements in Nd{sub 2}Fe{sub 14}B to the law of approach to saturation gave values for the magnetocrystalline anisotropy for the washed sample 2.23 × 10{sup 7} erg/cm{sup 3} and for the vacuum annealed sample 4.15 × 10{sup 7} erg/cm{sup 3}, both of which are lower than the bulk values. This would explain the lower values of H{sub c} observed in the particles.« less

Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2.

PubMed

Ogren, John I; Tong, Ashley L; Gordon, Samuel C; Chenu, Aurélia; Lu, Yue; Blankenship, Robert E; Cao, Jianshu; Schlau-Cohen, Gabriela S

2018-03-28

Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein-protein interactions and lipid-protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid-protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference to

The structure, stability, and infrared spectrum of B 2N, B 2N +, B 2N -, BO, B 2O and B 2N 2.

NASA Astrophysics Data System (ADS)

Martin, J. M. L.; François, J. P.; Gijbels, R.

1992-05-01

The structure, infrared spectrum, and heat of formation of B 2N, B 2N -, BO, and B 2O have been studied ab initio. B 2N is very stable; B 2O even more so. B 2N, B 2N -, B 2O, and probably B 2N + have symmetric linear ground-state structures; for B 2O, an asymmetric linear structure lies about 12 kcal/mol above the ground state. B 2N +, B 2N - and B 2O have intense asymmetric stretching frequencies, predicted near 870, 1590 and 1400 cm -1, respectively. Our predicted harmonic frequencies and isotopic shifts for B 2O confirm the recent experimental identification by Andrews and Burkholder. Absorptions at 1889.5 and 1998.5 cm -1 in noble-gas trapped boron nitride vapor belong the BNB and BNBN ( 3Π), respectively; a tentative assignment of 882.5 cm -1 to BNB + is proposed. Total atomization energies Σ De (Σ D0) are computed (accuracy ±2 kcal/mol) as: BO 193.1 (190.4), B 2O 292.5 (288.7), B 2N 225.0 (250.3) kcal/mol. The ionization potential and electron affinity of B 2N are predicted to be 8.62±0.1 and 3.34±0.1 eV. The MP4-level additivity approximations involved in G1 theory results in errors on the order of 1 kcal/mol in the Σ De values.

Elastic, inelastic, and 1 n transfer cross sections for the 10B+120Sn reaction

NASA Astrophysics Data System (ADS)

Gasques, L. R.; Freitas, A. S.; Chamon, L. C.; Oliveira, J. R. B.; Medina, N. H.; Scarduelli, V.; Rossi, E. S.; Alvarez, M. A. G.; Zagatto, V. A. B.; Lubian, J.; Nobre, G. P. A.; Padron, I.; Carlson, B. V.

2018-03-01

The 10B+120Sn reaction has been investigated at ELab=37.5 MeV. The cross sections for different channels, such as the elastic scattering, the excitation of the 2+ and 3-120Sn states, the excitation of the 1+ state of 10B, and the 1 n pick-up transfer, have been measured. One-step distorted-wave Born approximation and coupled-reaction-channels calculations have been performed in the context of the double-folding São Paulo potential. The effect of coupling the inelastic and transfer states on the angular distributions is discussed in the paper. In general, the theoretical calculations within the coupled-reaction-channels formalism yield a satisfactory agreement with the corresponding experimental angular distributions.

Transferring genomics to the clinic: distinguishing Burkitt and diffuse large B cell lymphomas.

PubMed

Sha, Chulin; Barrans, Sharon; Care, Matthew A; Cunningham, David; Tooze, Reuben M; Jack, Andrew; Westhead, David R

2015-01-01

Classifiers based on molecular criteria such as gene expression signatures have been developed to distinguish Burkitt lymphoma and diffuse large B cell lymphoma, which help to explore the intermediate cases where traditional diagnosis is difficult. Transfer of these research classifiers into a clinical setting is challenging because there are competing classifiers in the literature based on different methodology and gene sets with no clear best choice; classifiers based on one expression measurement platform may not transfer effectively to another; and, classifiers developed using fresh frozen samples may not work effectively with the commonly used and more convenient formalin fixed paraffin-embedded samples used in routine diagnosis. Here we thoroughly compared two published high profile classifiers developed on data from different Affymetrix array platforms and fresh-frozen tissue, examining their transferability and concordance. Based on this analysis, a new Burkitt and diffuse large B cell lymphoma classifier (BDC) was developed and employed on Illumina DASL data from our own paraffin-embedded samples, allowing comparison with the diagnosis made in a central haematopathology laboratory and evaluation of clinical relevance. We show that both previous classifiers can be recapitulated using very much smaller gene sets than originally employed, and that the classification result is closely dependent on the Burkitt lymphoma criteria applied in the training set. The BDC classification on our data exhibits high agreement (~95 %) with the original diagnosis. A simple outcome comparison in the patients presenting intermediate features on conventional criteria suggests that the cases classified as Burkitt lymphoma by BDC have worse response to standard diffuse large B cell lymphoma treatment than those classified as diffuse large B cell lymphoma. In this study, we comprehensively investigate two previous Burkitt lymphoma molecular classifiers, and implement a new gene

Superconducting MgB2 wires with vanadium diffusion barrier

NASA Astrophysics Data System (ADS)

Hušek, I.; Kováč, P.; Melišek, T.; Kulich, M.; Rosová, A.; Kopera, L.; Szundiová, B.

2017-10-01

Single-core MgB2 wires with a vanadium barrier and Cu stabilization have been made by the in situ powder-in-tube (PIT) and internal magnesium diffusion (IMD) into boron processes. Heat treatment of PIT wires was done at the temperature range of 650 °C-850 °C/30 min. Critical currents of differently treated MgB2/V/Cu wires have been measured and related with the structure of MgB2. It was found that critical current density of MgB2/V wire annealed above 700 °C decreases rapidly. The obtained results clearly show that vanadium is a well formable metal and can be applied as an effective diffusion barrier for MgB2 wires heat-treated at temperatures ≤700 °C. This temperature limit is well applicable for MgB2 wires with high current densities made by PIT and also by the IMD process.

Observation of the $$\\chi_\\mathrm{b1}$$(3P) and $$\\chi_\\mathrm{b2}$$(3P) and measurement of their masses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirunyan, Albert M; et al.

Themore » $$\\chi_\\mathrm{b1}$$(3P) and $$\\chi_\\mathrm{b3}$$(3P) states are observed through their $$\\Upsilon$$(3S) $$\\gamma$$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$$^{-1}$$. $$\\Upsilon$$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $$\\chi_\\mathrm{b}$$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$$\\,$$513.42 $$\\pm$$ 0.41 (stat) $$\\pm$$ 0.18 (syst) MeV and 10$$\\,$$524.02 $$\\pm$$ 0.57 (stat) $$\\pm$$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $$\\Upsilon$$(3S) mass, which has an uncertainty of 0.5 MeV. mass splitting is measured to be 10.60 $$\\pm$$ 0.64 (stat) $$\\pm$$ 0.17 (syst) MeV.« less

Validation of the Pangao PG-800B5 for clinical use and self-measurement according to the European Society of Hypertension International Protocol revision 2010.

PubMed

Chen, Wan; Zeng, Zhaolin; Li, Lizhi; Wan, Xiaofen; Wan, Yi

2014-10-01

This study aimed to validate the Pangao PG-800B5 upper arm blood pressure monitor according to the European Society of Hypertension International Protocol revision 2010. A total of 33 participants, 16 men and 17 women, were included in the device evaluation. The protocol requirements were followed precisely. The mean age of the participants was 56.4±21.0 years (range 22-84 years). The mean systolic blood pressure was 143.6±25.5 mmHg (range 98-188 mmHg), the mean diastolic blood pressure was 85.7±17.2 mmHg (range 49-125 mmHg), and the mean arm circumference was 26.1±2.2 cm (range 23-32 cm). On average, the device overestimated the systolic blood pressure by 0.9±4.2 mmHg and diastolic blood pressure by 0.7±4.5 mmHg. The device passed all requirements, fulfilling the standards of the protocol. Therefore, the Pangao PG-800B5 upper arm blood pressure monitor can be recommended for clinical use and self-measurement in an adult population.

Redshifted Cherenkov Radiation for in vivo Imaging: Coupling Cherenkov Radiation Energy Transfer to multiple Förster Resonance Energy Transfers

NASA Astrophysics Data System (ADS)

Bernhard, Yann; Collin, Bertrand; Decréau, Richard A.

2017-03-01

Cherenkov Radiation (CR), this blue glow seen in nuclear reactors, is an optical light originating from energetic β-emitter radionuclides. CR emitter 90Y triggers a cascade of energy transfers in the presence of a mixed population of fluorophores (which each other match their respective absorption and emission maxima): Cherenkov Radiation Energy Transfer (CRET) first, followed by multiple Förster Resonance Energy transfers (FRET): CRET ratios were calculated to give a rough estimate of the transfer efficiency. While CR is blue-weighted (300-500 nm), such cascades of Energy Transfers allowed to get a) fluorescence emission up to 710 nm, which is beyond the main CR window and within the near-infrared (NIR) window where biological tissues are most transparent, b) to amplify this emission and boost the radiance on that window: EMT6-tumor bearing mice injected with both a radionuclide and a mixture of fluorophores having a good spectral overlap, were shown to have nearly a two-fold radiance boost (measured on a NIR window centered on the emission wavelength of the last fluorophore in the Energy Transfer cascade) compared to a tumor injected with the radionuclide only. Some CR embarked light source could be converted into a near-infrared radiation, where biological tissues are most transparent.

Redshifted Cherenkov Radiation for in vivo Imaging: Coupling Cherenkov Radiation Energy Transfer to multiple Förster Resonance Energy Transfers.

PubMed

Bernhard, Yann; Collin, Bertrand; Decréau, Richard A

2017-03-24

Cherenkov Radiation (CR), this blue glow seen in nuclear reactors, is an optical light originating from energetic β-emitter radionuclides. CR emitter 90 Y triggers a cascade of energy transfers in the presence of a mixed population of fluorophores (which each other match their respective absorption and emission maxima): Cherenkov Radiation Energy Transfer (CRET) first, followed by multiple Förster Resonance Energy transfers (FRET): CRET ratios were calculated to give a rough estimate of the transfer efficiency. While CR is blue-weighted (300-500 nm), such cascades of Energy Transfers allowed to get a) fluorescence emission up to 710 nm, which is beyond the main CR window and within the near-infrared (NIR) window where biological tissues are most transparent, b) to amplify this emission and boost the radiance on that window: EMT6-tumor bearing mice injected with both a radionuclide and a mixture of fluorophores having a good spectral overlap, were shown to have nearly a two-fold radiance boost (measured on a NIR window centered on the emission wavelength of the last fluorophore in the Energy Transfer cascade) compared to a tumor injected with the radionuclide only. Some CR embarked light source could be converted into a near-infrared radiation, where biological tissues are most transparent.

Redshifted Cherenkov Radiation for in vivo Imaging: Coupling Cherenkov Radiation Energy Transfer to multiple Förster Resonance Energy Transfers

PubMed Central

Bernhard, Yann; Collin, Bertrand; Decréau, Richard A.

2017-01-01

Cherenkov Radiation (CR), this blue glow seen in nuclear reactors, is an optical light originating from energetic β-emitter radionuclides. CR emitter 90Y triggers a cascade of energy transfers in the presence of a mixed population of fluorophores (which each other match their respective absorption and emission maxima): Cherenkov Radiation Energy Transfer (CRET) first, followed by multiple Förster Resonance Energy transfers (FRET): CRET ratios were calculated to give a rough estimate of the transfer efficiency. While CR is blue-weighted (300–500 nm), such cascades of Energy Transfers allowed to get a) fluorescence emission up to 710 nm, which is beyond the main CR window and within the near-infrared (NIR) window where biological tissues are most transparent, b) to amplify this emission and boost the radiance on that window: EMT6-tumor bearing mice injected with both a radionuclide and a mixture of fluorophores having a good spectral overlap, were shown to have nearly a two-fold radiance boost (measured on a NIR window centered on the emission wavelength of the last fluorophore in the Energy Transfer cascade) compared to a tumor injected with the radionuclide only. Some CR embarked light source could be converted into a near-infrared radiation, where biological tissues are most transparent. PMID:28338043

Antitumor effect of nuclear factor-κB decoy transfer by mannose-modified bubble lipoplex into macrophages in mouse malignant ascites

PubMed Central

Kono, Yusuke; Kawakami, Shigeru; Higuchi, Yuriko; Maruyama, Kazuo; Yamashita, Fumiyoshi; Hashida, Mitsuru

2014-01-01

Patients with malignant ascites (MAs) display several symptoms, such as dyspnea, nausea, pain, and abdominal tenderness, resulting in a significant reduction in their quality of life. Tumor-associated macrophages (TAMs) play a crucial role in MA progression. Because TAMs have a tumor-promoting M2 phenotype, conversion of the M2 phenotypic function of TAMs would be promising for MA treatment. Nuclear factor-κB (NF-κB) is a master regulator of macrophage polarization. Here, we developed targeted transfer of a NF-κB decoy into TAMs by ultrasound (US)-responsive, mannose-modified liposome/NF-κB decoy complexes (Man-PEG bubble lipoplexes) in a mouse peritoneal dissemination model of Ehrlich ascites carcinoma. In addition, we investigated the effects of NF-κB decoy transfection into TAMs on MA progression and mouse survival rates. Intraperitoneal injection of Man-PEG bubble lipoplexes and US exposure transferred the NF-κB decoy into TAMs effectively. When the NF-κB decoy was delivered into TAMs by this method in the mouse peritoneal dissemination model, mRNA expression of the Th2 cytokine interleukin (IL)-10 in TAMs was decreased significantly. In contrast, mRNA levels of Th1 cytokines (IL-12, tumor necrosis factor-α, and IL-6) were increased significantly. Moreover, the expression level of vascular endothelial growth factor in ascites was suppressed significantly, and peritoneal angiogenesis showed a reduction. Furthermore, NF-κB decoy transfer into TAMs significantly decreased the ascitic volume and number of Ehrlich ascites carcinoma cells in ascites, and prolonged mouse survival. In conclusion, we transferred a NF-κB decoy efficiently by Man-PEG bubble lipoplexes with US exposure into TAMs, which may be a novel approach for MA treatment. PMID:24850474

B+27Al scattering at low energies

NASA Astrophysics Data System (ADS)

Morcelle, V.; Lichtenthäler, R.; Lépine-Szily, A.; Guimarães, V.; Pires, K. C. C.; Lubian, J.; Mendes Junior, D. R.; de Faria, P. N.; Kolata, J. J.; Becchetti, F. D.; Jiang, H.; Aguilera, E. F.; Lizcano, D.; Martinez-Quiroz, E.; Garcia, H.

2017-01-01

We present 8B 27Al elastic scattering angular distributions for the proton-halo nucleus 8B at two energies above the Coulomb barrier, namely Elab=15.3 and 21.7 MeV. The experiments were performed in the Radioactive Ion Beams in Brasil facility (RIBRAS) in São Paulo, and in the TwinSol facility at the University of Notre Dame, USA. The angular distributions were measured in the angular range of 15-80 degrees. Optical model and continuum discretized coupled channels calculations were performed, and the total reaction cross sections were derived. A comparison of the 8B+27Al total reaction cross sections with similar systems including exotic, weakly bound, and tightly bound projectiles impinging on the same target is presented.

HscA and HscB stimulate [2Fe-2S] cluster transfer from IscU to apoferredoxin in an ATP-dependent reaction.

PubMed

Chandramouli, Kala; Johnson, Michael K

2006-09-19

The role of the Azotobacter vinelandii HscA/HscB cochaperone system in ISC-mediated iron-sulfur cluster biogenesis has been investigated in vitro by using CD and EPR spectrometry to monitor the effect of HscA, HscB, MgATP, and MgADP on the time course of cluster transfer from [2Fe-2S]IscU to apo-Isc ferredoxin. CD spectra indicate that both HscB and HscA interact with [2Fe-2S]IscU and the rate of cluster transfer was stimulated more than 20-fold in the presence stoichiometric HscA and HscB and excess MgATP. No stimulation was observed in the absence of either HscB or MgATP, and cluster transfer was found to be an ATP-dependent reaction based on concomitant phosphate production and the enhanced rates of cluster transfer in the presence of KCl which is known to stimulate HscA ATPase activity. The results demonstrate a role of the ISC HscA/HscB cochaperone system in facilitating efficient [2Fe-2S] cluster transfer from the IscU scaffold protein to acceptor proteins and that [2Fe-2S] cluster transfer from IscU is an ATP-dependent process. The data are consistent with the proposed regulation of the HscA ATPase cycle by HscB and IscU [Silberg, J. J., Tapley, T. L., Hoff, K. G., and Vickery, L. E. (2004) J. Biol. Chem. 279, 53924-53931], and mechanistic proposals for coupling of the HscA ATPase cycle with cluster transfer from [2Fe-2S]IscU to apo-IscFdx are discussed.

High efficiency light harvesting by carotenoids in the LH2 complex from photosynthetic bacteria: unique adaptation to growth under low-light conditions.

PubMed

Magdaong, Nikki M; LaFountain, Amy M; Greco, Jordan A; Gardiner, Alastair T; Carey, Anne-Marie; Cogdell, Richard J; Gibson, George N; Birge, Robert R; Frank, Harry A

2014-09-25

Rhodopin, rhodopinal, and their glucoside derivatives are carotenoids that accumulate in different amounts in the photosynthetic bacterium, Rhodoblastus (Rbl.) acidophilus strain 7050, depending on the intensity of the light under which the organism is grown. The different growth conditions also have a profound effect on the spectra of the bacteriochlorophyll (BChl) pigments that assemble in the major LH2 light-harvesting pigment-protein complex. Under high-light conditions the well-characterized B800-850 LH2 complex is formed and accumulates rhodopin and rhodopin glucoside as the primary carotenoids. Under low-light conditions, a variant LH2, denoted B800-820, is formed, and rhodopinal and rhodopinal glucoside are the most abundant carotenoids. The present investigation compares and contrasts the spectral properties and dynamics of the excited states of rhodopin and rhodopinal in solution. In addition, the systematic differences in pigment composition and structure of the chromophores in the LH2 complexes provide an opportunity to explore the effect of these factors on the rate and efficiency of carotenoid-to-BChl energy transfer. It is found that the enzymatic conversion of rhodopin to rhodopinal by Rbl. acidophilus 7050 grown under low-light conditions results in nearly 100% carotenoid-to-BChl energy transfer efficiency in the LH2 complex. This comparative analysis provides insight into how photosynthetic systems are able to adapt and survive under challenging environmental conditions.

High Efficiency Light Harvesting by Carotenoids in the LH2 Complex from Photosynthetic Bacteria: Unique Adaptation to Growth under Low-Light Conditions

PubMed Central

2015-01-01

Rhodopin, rhodopinal, and their glucoside derivatives are carotenoids that accumulate in different amounts in the photosynthetic bacterium, Rhodoblastus (Rbl.) acidophilus strain 7050, depending on the intensity of the light under which the organism is grown. The different growth conditions also have a profound effect on the spectra of the bacteriochlorophyll (BChl) pigments that assemble in the major LH2 light-harvesting pigment–protein complex. Under high-light conditions the well-characterized B800-850 LH2 complex is formed and accumulates rhodopin and rhodopin glucoside as the primary carotenoids. Under low-light conditions, a variant LH2, denoted B800-820, is formed, and rhodopinal and rhodopinal glucoside are the most abundant carotenoids. The present investigation compares and contrasts the spectral properties and dynamics of the excited states of rhodopin and rhodopinal in solution. In addition, the systematic differences in pigment composition and structure of the chromophores in the LH2 complexes provide an opportunity to explore the effect of these factors on the rate and efficiency of carotenoid-to-BChl energy transfer. It is found that the enzymatic conversion of rhodopin to rhodopinal by Rbl. acidophilus 7050 grown under low-light conditions results in nearly 100% carotenoid-to-BChl energy transfer efficiency in the LH2 complex. This comparative analysis provides insight into how photosynthetic systems are able to adapt and survive under challenging environmental conditions. PMID:25171303

Elastic, inelastic, and 1 n transfer cross sections for the B 10 + Sn 120 reaction

DOE PAGES

Gasques, L. R.; Freitas, A. S.; Chamon, L. C.; ...

2018-03-30

The 10B+ 120Sn reaction has been investigated at E Lab=37.5 MeV. The cross sections for different channels, such as the elastic scattering, the excitation of the 2 + and 3 -120Sn states, the excitation of the 1 + state of 10B, and the 1n pick-up transfer, have been measured. One-step distorted-wave Born approximation and coupled-reaction-channels calculations have been performed in the context of the double-folding São Paulo potential. Here, the effect of coupling the inelastic and transfer states on the angular distributions is discussed in the paper. In general, the theoretical calculations within the coupled-reaction-channels formalism yield a satisfactory agreementmore » with the corresponding experimental angular distributions.« less

Elastic, inelastic, and 1 n transfer cross sections for the B 10 + Sn 120 reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gasques, L. R.; Freitas, A. S.; Chamon, L. C.

The 10B+ 120Sn reaction has been investigated at E Lab=37.5 MeV. The cross sections for different channels, such as the elastic scattering, the excitation of the 2 + and 3 -120Sn states, the excitation of the 1 + state of 10B, and the 1n pick-up transfer, have been measured. One-step distorted-wave Born approximation and coupled-reaction-channels calculations have been performed in the context of the double-folding São Paulo potential. Here, the effect of coupling the inelastic and transfer states on the angular distributions is discussed in the paper. In general, the theoretical calculations within the coupled-reaction-channels formalism yield a satisfactory agreementmore » with the corresponding experimental angular distributions.« less

Implementing the Simple Biosphere Model (SiB) in a general circulation model: Methodologies and results

NASA Technical Reports Server (NTRS)

Sato, N.; Sellers, P. J.; Randall, D. A.; Schneider, E. K.; Shukla, J.; Kinter, J. L., III; Hou, Y.-T.; Albertazzi, E.

1989-01-01

The Simple Biosphere MOdel (SiB) of Sellers et al., (1986) was designed to simulate the interactions between the Earth's land surface and the atmosphere by treating the vegetation explicitly and relistically, thereby incorporating biophysical controls on the exchanges of radiation, momentum, sensible and latent heat between the two systems. The steps taken to implement SiB in a modified version of the National Meteorological Center's spectral GCM are described. The coupled model (SiB-GCM) was used with a conventional hydrological model (Ctl-GCM) to produce summer and winter simulations. The same GCM was used with a conventional hydrological model (Ctl-GCM) to produce comparable 'control' summer and winter variations. It was found that SiB-GCM produced a more realistic partitioning of energy at the land surface than Ctl-GCM. Generally, SiB-GCM produced more sensible heat flux and less latent heat flux over vegetated land than did Ctl-GCM and this resulted in the development of a much deeper daytime planetary boundary and reduced precipitation rates over the continents in SiB-GCM. In the summer simulation, the 200 mb jet stream and the wind speed at 850 mb were slightly weakened in the SiB-GCM relative to the Ctl-GCM results and equivalent analyses from observations.

10 CFR 850.39 - Recordkeeping and use of information.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Recordkeeping and use of information. 850.39 Section 850... Requirements § 850.39 Recordkeeping and use of information. (a) The responsible employer must establish and maintain accurate records of all beryllium inventory information, hazard assessments, exposure measurements...

Fluoro-Phenyl-Styrene-Sulfonamide, a Novel Inhibitor of σB Activity, Prevents the Activation of σB by Environmental and Energy Stresses in Bacillus subtilis

PubMed Central

Ringus, Daina L.; Gaballa, Ahmed; Helmann, John D.; Wiedmann, Martin

2013-01-01

Sigma B (σB) is an alternative sigma factor that regulates the general stress response in Bacillus subtilis and in many other Gram-positive organisms. σB activity in B. subtilis is tightly regulated via at least three distinct pathways within a complex signal transduction cascade in response to a variety of stresses, including environmental stress, energy stress, and growth at high or low temperatures. We probed the ability of fluoro-phenyl-styrene-sulfonamide (FPSS), a small-molecule inhibitor of σB activity in Listeria monocytogenes, to inhibit σB activity in B. subtilis through perturbation of signal transduction cascades under various stress conditions. FPSS inhibited the activation of σB in response to multiple categories of stress known to induce σB activity in B. subtilis. Specifically, FPSS prevented the induction of σB activity in response to energy stress, including entry into stationary phase, phosphate limitation, and azide stress. FPSS also inhibited chill induction of σB activity in a ΔrsbV strain, suggesting that FPSS does not exclusively target the RsbU and RsbP phosphatases or the anti–anti-sigma factor RsbV, all of which contribute to posttranslational regulation of σB activity. Genetic and biochemical experiments, including artificial induction of σB, analysis of the phosphorylation state of the anti–anti-sigma factor RsbV, and in vitro transcription assays, indicate that while FPSS does not bind directly to σB to inhibit activity, it appears to prevent the release of B. subtilis σB from its anti-sigma factor RsbW. PMID:23524614

78 FR 42701 - Improving Public Safety Communications in the 800 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-17

...] Improving Public Safety Communications in the 800 MHz Band AGENCY: Federal Communications Commission. ACTION...-901 MHz/935- 940 MHz band (900 MHz B/ILT Band) to allow a qualified entity to file an application for..., manufacturing, energy) to non-commercial (e.g., clerical, educational, philanthropic, medical). In 2004, the...

Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quadir, G. A., E-mail: Irfan-magami@Rediffmail.com, E-mail: gaquadir@gmail.com; Badruddin, Irfan Anjum

2016-06-08

This work is continuation of the paper Part A. Due to large number of results, the paper is divided into two section with section-A (Part A) discussing the effect of various parameters such as heat transfer coefficient parameter, thermal conductivity ratio etc. on streamlines and isothermal lines. Section-B highlights the heat transfer characteristics in terms of Nusselt number The Darcy model is employed to simulate the flow inside the medium. It is assumed that the heat transfer takes place by convection and radiation. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method.

Pathways of energy transfer in LHCII revealed by room-temperature 2D electronic spectroscopy.

PubMed

Wells, Kym L; Lambrev, Petar H; Zhang, Zhengyang; Garab, Gyözö; Tan, Howe-Siang

2014-06-21

We present here the first room-temperature 2D electronic spectroscopy study of energy transfer in the plant light-harvesting complex II, LHCII. Two-dimensional electronic spectroscopy has been used to study energy transfer dynamics in LHCII trimers from the chlorophyll b Qy band to the chlorophyll a Qy band. Observing cross-peak regions corresponding to couplings between different excitonic states reveals partially resolved fine structure at the exciton level that cannot be isolated by pump-probe or linear spectroscopy measurements alone. Global analysis of the data has been performed to identify the pathways and time constants of energy transfer. The measured waiting time (Tw) dependent 2D spectra are found to be composed of 2D decay-associated spectra with three timescales (0.3 ps, 2.3 ps and >20 ps). Direct and multistep cascading pathways from the high-energy chlorophyll b states to the lowest-energy chlorophyll a states have been resolved occurring on time scales of hundreds of femtoseconds to picoseconds.

Mechanism of Selective Nickel Transfer from HypB to HypA, Escherichia coli [NiFe]-Hydrogenase Accessory Proteins.

PubMed

Lacasse, Michael J; Douglas, Colin D; Zamble, Deborah B

2016-12-13

[NiFe]-hydrogenase enzymes catalyze the reversible reduction of protons to molecular hydrogen and serve as a vital component of the metabolism of many pathogens. The synthesis of the bimetallic catalytic center requires a suite of accessory proteins, and the penultimate step, nickel insertion, is facilitated by the metallochaperones HypA and HypB. In Escherichia coli, nickel moves from a site in the GTPase domain of HypB to HypA in a process accelerated by GDP. To determine how the transfer of nickel is controlled, the impacts of HypA and nucleotides on the properties of HypB were examined. Integral to this work was His2Gln HypA, a mutant with attenuated nickel affinity that does not support hydrogenase production in E. coli. This mutation inhibits the translocation of nickel from HypB. H2Q-HypA does not modulate the apparent metal affinity of HypB, but the stoichiometry and stability of the HypB-nickel complex are modulated by the nucleotide. Furthermore, the HypA-HypB interaction was detected by gel filtration chromatography if HypB was loaded with GDP, but not a GTP analogue, and the protein complex dissociated upon binding of nickel to His2 of HypA. In contrast, a nucleotide does not modulate the binding of zinc to HypB, and loading zinc into the GTPase domain of HypB inhibits formation of the complex with HypA. These results demonstrate that GTP hydrolysis controls both metal binding and protein-protein interactions, conferring selective and directional nickel transfer during [NiFe]-hydrogenase biosynthesis.

HscA and HscB stimulate [2Fe-2S] cluster transfer from IscU to apo-ferredoxin in an ATP-dependent reaction†

PubMed Central

Chandramouli, Kala; Johnson, Michael K.

2008-01-01

The role of the Azotobacter vinelandii HscA/HscB co-chaperone system in ISC-mediated iron-sulfur cluster biogenesis has been investigated in vitro by using CD and EPR spectrometry to monitor the effect of HscA, HscB, MgATP, and MgADP on the time course of cluster transfer from [2Fe-2S]IscU to apo-Isc ferredoxin. CD spectra indicate that both HscB and HscA interact with [2Fe-2S] IscU and the rate of cluster transfer was stimulated more than 20-fold in the presence stoichiometric HscA and HscB and excess MgATP. No stimulation was observed in the absence of either HscB or MgATP and cluster transfer was found to be an ATP-dependent reaction based on concomitant phosphate production and the enhanced rates of cluster transfer in the presence of KCl which is known to stimulated HscA ATPase activity. The results demonstrate a role of the ISC HscA/HscB co-chaperone system in facilitating efficient [2Fe-2S] cluster transfer from the IscU scaffold protein to acceptor proteins and that [2Fe-2S] cluster transfer from IscU is an ATP-dependent process. The data are consistent with the proposed regulation of the HscA ATPase cycle by HscB and IscU (Silberg, J. J., Tapley, T. L., Hoff, K. G., and Vickery, L. E. (2004) J. Biol. Chem. 279, 53924-53931), and mechanistic proposals for coupling of the HscA ATPase cycle with cluster transfer from [2Fe-2S]IscU to apo-IscFdx are discussed. PMID:16964969

Energy transfer dynamics in trimers and aggregates of light-harvesting complex II probed by 2D electronic spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enriquez, Miriam M.; Zhang, Cheng; Tan, Howe-Siang, E-mail: howesiang@ntu.edu.sg

2015-06-07

The pathways and dynamics of excitation energy transfer between the chlorophyll (Chl) domains in solubilized trimeric and aggregated light-harvesting complex II (LHCII) are examined using two-dimensional electronic spectroscopy (2DES). The LHCII trimers and aggregates exhibit the unquenched and quenched excitonic states of Chl a, respectively. 2DES allows direct correlation of excitation and emission energies of coupled states over population time delays, hence enabling mapping of the energy flow between Chls. By the excitation of the entire Chl b Q{sub y} band, energy transfer from Chl b to Chl a states is monitored in the LHCII trimers and aggregates. Global analysismore » of the two-dimensional (2D) spectra reveals that energy transfer from Chl b to Chl a occurs on fast and slow time scales of 240–270 fs and 2.8 ps for both forms of LHCII. 2D decay-associated spectra resulting from the global analysis identify the correlation between Chl states involved in the energy transfer and decay at a given lifetime. The contribution of singlet–singlet annihilation on the kinetics of Chl energy transfer and decay is also modelled and discussed. The results show a marked change in the energy transfer kinetics in the time range of a few picoseconds. Owing to slow energy equilibration processes, long-lived intermediate Chl a states are present in solubilized trimers, while in aggregates, the population decay of these excited states is significantly accelerated, suggesting that, overall, the energy transfer within the LHCII complexes is faster in the aggregated state.« less

In Vivo 18-FDG/18-Choline-Mediated Cerenkov Radiation Energy Transfer (CRET) Multiplexed Optical Imaging for Human Prostate Carcinoma Detection and Staging

DTIC Science & Technology

2017-12-01

AWARD NUMBER: W81XWH-13-1-0138 TITLE: In Vivo 18-FDG/18-Choline-Mediated Cerenkov Radiation Energy Transfer (CRET) Multiplexed Optical...18Ffluorocholine/ 18F-FDG Cerenkov radiation energy transfer (CRET) coupled with TF- and ErbB2/3- molecularly targeted nearinfrared (NIR) QDs can be used to detect...to examine whether internal illumination via 18F-fluorocholine Cerenkov radiation energy transfer (CRET) coupled with TF- and ErbB2/3- molecularly

Rab11b mediates melanin transfer between donor melanocytes and acceptor keratinocytes via coupled exo/endocytosis.

PubMed

Tarafder, Abul K; Bolasco, Giulia; Correia, Maria S; Pereira, Francisco J C; Iannone, Lucio; Hume, Alistair N; Kirkpatrick, Niall; Picardo, Mauro; Torrisi, Maria R; Rodrigues, Inês P; Ramalho, José S; Futter, Clare E; Barral, Duarte C; Seabra, Miguel C

2014-04-01

The transfer of melanin from melanocytes to keratinocytes is a crucial process underlying maintenance of skin pigmentation and photoprotection against UV damage. Here, we present evidence supporting coupled exocytosis of the melanin core, or melanocore, by melanocytes and subsequent endocytosis by keratinocytes as a predominant mechanism of melanin transfer. Electron microscopy analysis of human skin samples revealed three lines of evidence supporting this: (1) the presence of melanocores in the extracellular space; (2) within keratinocytes, melanin was surrounded by a single membrane; and (3) this membrane lacked the melanosomal membrane protein tyrosinase-related protein 1 (TYRP1). Moreover, co-culture of melanocytes and keratinocytes suggests that melanin exocytosis is specifically induced by keratinocytes. Furthermore, depletion of Rab11b, but not Rab27a, caused a marked decrease in both keratinocyte-stimulated melanin exocytosis and transfer to keratinocytes. Thus, we propose that the predominant mechanism of melanin transfer is keratinocyte-induced exocytosis, mediated by Rab11b through remodeling of the melanosome membrane, followed by subsequent endocytosis by keratinocytes.

Nonradiative inter- and intramolecular energy transfer from the aromatic donor anisole to a synthesized photoswitchable acceptor system.

PubMed

Bardhan, Munmun; Bhattacharya, Sudeshna; Misra, Tapas; Mukhopadhyay, Rupa; De, Asish; Chowdhury, Joydeep; Ganguly, Tapan

2010-02-01

We report steady state and time resolved fluorescence measurements on acetonitrile (ACN) solutions of the model compounds, energy donor anisole (A) and a photoswitchable acceptor N,N'-1,2-phenylene di-p-tosylamide (B) and the multichromophore (M) where A and B are connected by a spacer containing both rigid triple (acetylenic) and flexible methylene bonds. Both steady state and time correlated single photon counting measurements demonstrate that though intermolecular energy transfer, of Forster type, between the donor and acceptor moieties occurs with rate 10(8)s(-1) but when these two reacting components are linked by a spacer (multichromophore, M) the observed transfer rate ( approximately 10(11)s(-1)) enhances. This seemingly indicates that the imposition of the spacer by inserting a triple bond may facilitate in the propagation of electronic excitation energy through bond. The time resolved fluorescence measurements along with the theoretical predictions using Configuration interaction singles (CIS) method by using 6-31G (d,p) basis set, implemented in the Gaussian package indicate the formations of the two excited conformers of B. The experimental findings made from the steady state and time resolved fluorescence measurements demonstrate that, though two different isomeric species of the acceptor B are formed in the excited singlet states, the prevailing singlet-singlet nonradiative energy transfer route was found from the donor A to the relatively longer-lived isomeric species of B. Copyright (c) 2009 Elsevier B.V. All rights reserved.

10B(n,α)7Li and 10B(n,α1γ)7Li cross section data up to 3 MeV incident neutron energy

NASA Astrophysics Data System (ADS)

Bevilacqua, Riccardo; Hambsch, Franz-Josef; Vidali, Marzio; Ruskov, Ivan; Lamia, Livio

2017-09-01

The 10B(n,α) reaction cross-section is a well-established neutron cross-section standard for incident neutron energies up to 1 MeV. However, above this energy limit there are only scarce direct (n,α) measurements available and these few experimental data are showing large inconsistencies with each other. These discrepancies are reflected in the evaluated data libraries: ENDF/B-VII.1, JEFF-3.1.2 and JENDL-4.0 are in excellent agreement up to 100 keV incident neutrons, whereas the 10B(n,α) data in the different libraries show large differences in the MeV region. To address these inconsistencies, we have measured the cross section of the two branches of the 10B(n,α) reaction for incident neutron energies up to 3 MeV. We present here the 10B(n,α) and the 10B(n,α1γ) reactions cross section data, their branching ratio and the total 10B(n,α) reaction cross section. The measurements were conducted with a dedicated Frisch-grid ionization chamber installed at the GELINA pulsed neutron source of the EC-JRC. We compare our results with existing experimental data and evaluations.

Quantitative calculations of fluorescence polarization and absorption anisotropy kinetics of double- and triple-chromophore complexes with energy transfer.

PubMed Central

Demidov, A A

1994-01-01

A new method is presented for calculation of the fluorescence depolarization and kinetics of absorption anisotropy for molecular complexes with a limited number of chromophores. The method considers absorption and emission of light by both chromophores, and also energy transfer between them, with regard to their mutual orientations. The chromophores in each individual complex are rigidly positioned. The complexes are randomly distributed and oriented in space, and there is no energy transfer between them. The new "practical" formula for absorption anisotropy and fluorescence depolarization kinetics, P(t) = [3B(t) - 1 + 2A(t)]/[3 + B(t) + 4A(t)], is derived both for double- and triple-chromophore complexes with delta-pulse excitation. The parameter B(t) is given by (a) B(t) = cos2(theta) for double-chromophore complexes, and (b) B(t) = q12(t)cos2(theta 12) + q13(t)-cos2(theta 13) + q23(t)cos2(theta 23) for triple-chromophore complexes, where q12(t) + q13(t) + q23(t) = 1. Here theta ij are the angles between the chromophore transition dipole moments in the individual molecular complex. The parameters qij(t) and A(t) are dependent on chromophore spectroscopic features and on the rates of energy transfer. PMID:7696461

Design of triads for probing the direct through space energy transfers in closely spaced assemblies.

PubMed

Camus, Jean-Michel; Aly, Shawkat M; Fortin, Daniel; Guilard, Roger; Harvey, Pierre D

2013-08-05

Using a selective stepwise Suzuki cross-coupling reaction, two trimers built on three different chromophores were prepared. These trimers exhibit a D(^)A1-A2 structure where the donor D (octa-β-alkyl zinc(II)porphyrin either as diethylhexamethyl, 10a, or tetraethyltetramethyl, 10b, derivatives) through space transfers the S1 energy to two different acceptors, di(4-ethylbenzene) zinc(II)porphyrin (A1; acceptor 1) placed cofacial with D, and the corresponding free base (A2; acceptor 2), which is meso-meso-linked with A1. This structure design allows for the possibility of comparing two series of assemblies, 9a,b (D(^)A1) with 10a,b (D(^)Â1-A2), for the evaluation of the S1 energy transfer for the global process D*→A2 in the trimers. From the comparison of the decays of the fluorescence of D, the rates for through space energy transfer, kET for 10a,b (kET ≈ 6.4 × 10(9) (10a), 5.9 × 10(9) s(-1) (10b)), and those for the corresponding cofacial D(^)A1 systems, 9a,b, (kET ≈ 5.0 × 10(9) (9a), 4.7 × 10(9) s(-1) (9b)), provide an estimate for kET for the direct through space D*→A2 process (i.e., kET(D(^)A1-A2) - kET(D(^)A1) = kET(D*→A2) ∼ 1 × 10(9) s(-1)). This channel of relaxation represents ∼15% of kET for D*→A1.

Diverse dissolution-recrystallization structural transformations and sequential Förster resonance energy transfer behavior of a luminescent porous Cd-MOF.

PubMed

Cao, Li-Hui; Li, Hai-Yang; Xu, Hong; Wei, Yong-Li; Zang, Shuang-Quan

2017-09-12

Metal-organic frameworks (MOFs) with light-harvesting building blocks provide an excellent platform to study energy transfer in networks with well-defined structures. Here, we report the synthesis, dissolution-recrystallization structural transformation (DRST) and the Förster resonance energy transfer (FRET) properties of a 2D microporous MOF {[Cd 2 (L 1 ) 3 (Hdabco) 2 ]·5DMAc·6H 2 O} n (Cd-MOF, 1). Complex 1 can be dissolved in water and three other products with different dimensions recrystallized from the aqueous solution under diverse reaction conditions were obtained. Due to the porosity and excellent blue luminescence properties of complex 1, we also studied the FRET process between 1 and guest dyes. Two distinct organic dye molecules viz., acridine orange (AO) and rhodamine B (RhB), are encapsulated in 1 which has honeycomb-type nanochannels, and their influence on fluorescence emission has also been studied. The microporous complex 1 in (AO + RhB)@1 serves as an energy funnel that harvests high energy excitation and channels it onto AO and then onto RhB. The steady-state fluorescence and fluorescence dynamics of emission reveal successfully the process of stepwise vectorial energy transfer. Therefore, MOFs could be a class of promising host materials to be further explored in the field of energy transfer between MOF-host and organic guests.

Cyclodextrin-enhanced extraction and energy transfer of carcinogens in complex oil environments.

PubMed

Serio, Nicole; Chanthalyma, Chitapom; Prignano, Lindsey; Levine, Mindy

2013-11-27

Reported herein is the use of γ-cyclodextrin for two tandem functions: (a) the extraction of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from oil samples into aqueous solution and (b) the promotion of highly efficient energy transfer from the newly extracted PAHs to a high-quantum-yield fluorophore. The extraction proceeded in moderate to good efficiencies, and the resulting cyclodextrin-promoted energy transfer led to a new, brightly fluorescent signal in aqueous solution. The resulting dual-function system (extraction followed by energy transfer) has significant relevance in the environmental detection and cleanup of oil-spill-related carcinogens.

Evidence of excited state localization and static disorder in LH2 investigated by 2D-polarization single-molecule imaging at room temperature.

PubMed

Tubasum, Sumera; Camacho, Rafael; Meyer, Matthias; Yadav, Dheerendra; Cogdell, Richard J; Pullerits, Tõnu; Scheblykin, Ivan G

2013-12-07

Two-dimensional polarization fluorescence imaging of single light harvesting complexes 2 (LH2) of Rps. acidophila was carried out to investigate the polarization properties of excitation and fluorescence emission simultaneously, at room temperature. In two separate experiments we excited LH2 with a spectrally narrow laser line matched to the absorption bands of the two chromophore rings, B800 and B850, thereby indirectly and directly triggering fluorescence of the B850 exciton state. A correlation analysis of the polarization modulation depths in excitation and emission for a large number of single complexes was performed. Our results show, in comparison to B800, that the B850 ring is a more isotropic absorber due to the excitonic nature of its excited states. At the same time, we observed a strong tendency for LH2 to emit with dipolar character, from which preferential localization of the emissive exciton, stable for minutes, is inferred. We argue that the observed effects can consistently be explained by static energetic disorder and/or deformation of the complex, with possible involvement of exciton self-trapping.

Energy system contribution to 400-metre and 800-metre track running.

PubMed

Duffield, Rob; Dawson, Brian; Goodman, Carmel

2005-03-01

As a wide range of values has been reported for the relative energetics of 400-m and 800-m track running events, this study aimed to quantify the respective aerobic and anaerobic energy contributions to these events during track running. Sixteen trained 400-m (11 males, 5 females) and 11 trained 800-m (9 males, 2 females) athletes participated in this study. The participants performed (on separate days) a laboratory graded exercsie test and multiple race time-trials. The relative energy system contribution was calculated by multiple methods based upon measures of race VO2, accumulated oxygen deficit (AOD), blood lactate and estimated phosphocreatine degradation (lactate/PCr). The aerobic/anaerobic energy system contribution (AOD method) to the 400-m event was calculated as 41/59% (male) and 45/55% (female). For the 800-m event, an increased aerobic involvement was noted with a 60/40% (male) and 70/30% (female) respective contribution. Significant (P < 0.05) negative correlations were noted between race performance and anaerobic energy system involvement (lactate/PCr) for the male 800-m and female 400-m events (r = - 0.77 and - 0.87 respectively). These track running data compare well with previous estimates of the relative energy system contributions to the 400-m and 800-m events. Additionally, the relative importance and speed of interaction of the respective metabolic pathways has implications to training for these events.

Lipid transfer particle from the silkworm, Bombyx mori, is a novel member of the apoB/large lipid transfer protein family[S

PubMed Central

Yokoyama, Hiroshi; Yokoyama, Takeru; Yuasa, Masashi; Fujimoto, Hirofumi; Sakudoh, Takashi; Honda, Naoko; Fugo, Hajime; Tsuchida, Kozo

2013-01-01

Lipid transfer particle (LTP) is a high-molecular-weight, very high-density lipoprotein known to catalyze the transfer of lipids between a variety of lipoproteins, including both insects and vertebrates. Studying the biosynthesis and regulation pathways of LTP in detail has not been possible due to a lack of information regarding the apoproteins. Here, we sequenced the cDNA and deduced amino acid sequences for three apoproteins of LTP from the silkworm (Bombyx mori). The three subunit proteins of the LTP are coded by two genes, apoLTP-II/I and apoLTP-III. ApoLTP-I and apoLTP-II are predicted to be generated by posttranslational cleavage of the precursor protein, apoLTP-II/I. Clusters of amphipathic secondary structure within apoLTP-II/I are similar to Homo sapiens apolipoprotein B (apoB) and insect lipophorins. The apoLTP-II/I gene is a novel member of the apoB/large lipid transfer protein gene family. ApoLTP-III has a putative conserved juvenile hormone-binding protein superfamily domain. Expression of apoLTP-II/I and apoLTP-III genes was synchronized and both genes were primarily expressed in the fat body at the stage corresponding to increased lipid transport needs. We are now in a position to study in detail the physiological role of LTP and its biosynthesis and assembly. PMID:23812557

Breakup of 8B on 58Ni at energies around the Coulomb barrier and the astrophysical S17(0) factor revisited

NASA Astrophysics Data System (ADS)

Morales-Rivera, J. C.; Belyaeva, T. L.; Amador-Valenzuela, P.; Aguilera, E. F.; Martinez-Quiroz, E.; Kolata, J. J.

2018-01-01

Calculations of breakup and direct proton transfer for the 8B+58Ni system at energies around the Coulomb barrier (EB,lab=22.95 MeV) were performed by the continuum-discretized coupled channels (CDCC) method and the coupled-reaction-channels (CRC) method, respectively. For the 7Be+58Ni interaction, we used a semimicroscopic optical model potential (OMP) that combines microscopic calculations of the mean-field double folding potential and a phenomenological construction of the dynamical polarization potential (DPP). The 7Be angular distribution at Elab=25.75 MeV from the 8B breakup on 58Ni was calculated and the spectroscopic factor for 8B → 7Be+p vertex, Sexpt = 1.10 ± 0.05, was deduced. The astrophysical S17(0) factor was calculated equal to 20.7 ±1.1 eV•b, being in good agreement with the previously reported values.

Targeted Segment Transfer from Rye Chromosome 2R to Wheat Chromosomes 2A, 2B, and 7B.

PubMed

Ren, Tianheng; Li, Zhi; Yan, Benju; Tan, Feiquan; Tang, Zongxiang; Fu, Shulan; Yang, Manyu; Ren, Zhenglong

2017-01-01

Increased chromosome instability was induced by a rye (Secale cereale L.) monosomic 2R chromosome into wheat (Triticum aestivum L.). Centromere breakage and telomere dysfunction result in high rates of chromosome aberrations, including breakages, fissions, fusions, deletions, and translocations. Plants with target traits were sequentially selected to produce a breeding population, from which 3 translocation lines with target traits have been selected. In these lines, wheat chromosomes 2A, 2B, and 7B recombined with segments of the rye chromosome arm 2RL. This was detected by FISH analysis using repeat sequences pSc119.2, pAs1 and genomic DNA of rye together as probes. The translocation chromosomes in these lines were named as 2ASMR, 2BSMR, and 7BSMR. The small segments that were transferred into wheat consisted of pSc119.2 repeats and other chromatin regions that conferred resistance to stripe rust and expressed target traits. These translocation lines were highly resistant to stripe rust, and expressed several typical traits that were associated with chromosome arm 2RL, which are better than those of its wheat parent, disomic addition, and substitution lines that show agronomic characteristics. The integration of molecular methods and conventional techniques to improve wheat breeding schemes are discussed. © 2017 S. Karger AG, Basel.

Highly Efficient Green-Emitting Phosphors Ba2Y5B5O17 with Low Thermal Quenching Due to Fast Energy Transfer from Ce3+ to Tb3.

PubMed

Xiao, Yu; Hao, Zhendong; Zhang, Liangliang; Xiao, Wenge; Wu, Dan; Zhang, Xia; Pan, Guo-Hui; Luo, Yongshi; Zhang, Jiahua

2017-04-17

This paper demonstrates a highly thermally stable and efficient green-emitting Ba 2 Y 5 B 5 O 17 :Ce 3+ , Tb 3+ phosphor prepared by high-temperature solid-state reaction. The phosphor exhibits a blue emission band of Ce 3+ and green emission lines of Tb 3+ upon Ce 3+ excitation in the near-UV spectral region. The effect of Ce 3+ to Tb 3+ energy transfer on blue to green emission color tuning and on luminescence thermal stability is studied in the samples codoped with 1% Ce 3+ and various concentrations (0-40%) of Tb 3+ . The green emission of Tb 3+ upon Ce 3+ excitation at 150 °C can keep, on average, 92% of its intensity at room temperature, with the best one showing no intensity decreasing up to 210 °C for 30% Tb 3+ . Meanwhile, Ce 3+ emission intensity only keeps 42% on average at 150 °C. The high thermal stability of the green emission is attributed to suppression of Ce 3+ thermal de-excitation through fast energy transfer to Tb 3+ , which in the green-emitting excited states is highly thermally stable such that no lifetime shortening is observed with raising temperature to 210 °C. The predominant green emission is observed for Tb 3+ concentration of at least 10% due to efficient energy transfer with the transfer efficiency approaching 100% for 40% Tb 3+ . The internal and external quantum yield of the sample with Tb 3+ concentration of 20% can be as high as 76% and 55%, respectively. The green phosphor, thus, shows attractive performance for near-UV-based white-light-emitting diodes applications.

Immunomodulation by adoptive regulatory T-cell transfer improves Coxsackievirus B3-induced myocarditis.

PubMed

Pappritz, Kathleen; Savvatis, Konstantinos; Miteva, Kapka; Kerim, Bahtiyar; Dong, Fengquan; Fechner, Henry; Müller, Irene; Brandt, Christine; Lopez, Begoña; González, Arantxa; Ravassa, Susana; Klingel, Karin; Diez, Javier; Reinke, Petra; Volk, Hans-Dieter; Van Linthout, Sophie; Tschöpe, Carsten

2018-06-04

Regulatory T (T reg ) cells offer new therapeutic options for controlling undesired systemic and local immune responses. The aim of the current study was to determine the impact of therapeutic T reg administration on systemic and cardiac inflammation and remodeling in coxsackievirus B3 (CVB3) -induced myocarditis. Therefore, syngeneic T reg cells were applied intravenously in CVB3-infected mice 3 d after infection. Compared with CVB3 + PBS mice, CVB3 + T reg mice exhibited lower left ventricular (LV) chemokine expression, accompanied by reduced cardiac presence of proinflammatory Ly6C high CCR2 high Cx3Cr1 low monocytes and higher retention of proinflammatory Ly6C mid CCR2 high Cx3Cr1 low monocytes in the spleen. In addition, splenic myelopoiesis was reduced in CVB3 + T reg compared with CVB3 + PBS mice. Coculture of T reg cells with splenocytes isolated from mice 3 d post-CVB3 infection further demonstrated the ability of T reg cells to modulate monocyte differentiation in favor of the anti-inflammatory Ly6C low CCR2 low Cx3Cr1 high subset. T reg -mediated immunomodulation was paralleled by lower collagen 1 protein expression and decreased levels of soluble and insoluble collagen in LV of CVB3 + T reg compared with CVB3 + PBS mice. In agreement with these findings, LV systolic and diastolic function was improved in CVB3 + T reg mice compared with CVB3 + PBS mice. In summary, adoptive T reg transfer in the inflammatory phase of viral-induced myocarditis protects the heart against inflammatory damage and fibrosis via modulation of monocyte subsets.-Pappritz, K., Savvatis, K., Miteva, K., Kerim, B., Dong, F., Fechner, H., Müller, I., Brandt, C., Lopez, B., González, A., Ravassa, S., Klingel, K., Diez, J., Reinke, P., Volk, H.-D., Van Linthout, S., Tschöpe, C. Immunomodulation by adoptive regulatory T-cell transfer improves Coxsackievirus B3-induced myocarditis.

Biochemical traits and proteomic changes in postharvest flowers of medicinal chrysanthemum exposed to enhanced UV-B radiation.

PubMed

Yao, Xiaoqin; Chu, Jian-Zhou; Ma, Chun-Hui; Si, Chao; Li, Ji-Gang; Shi, Xiao-Fei; Liu, Chao-Nan

2015-08-01

The article studied UV-B effects on biochemical traits and proteomic changes in postharvest flowers of medicinal chrysanthemum. The experiment about UV-B effects on biochemical traits in flowers included six levels of UV-B treatments (0 (UV0), 50 (UV50), 200 (UV200), 400 (UV400), 600 (UV600) and 800 (UV800) μWcm(-2)). UV400, UV600 and UV800 treatments significantly increased the contents of hydrogen peroxide, malondialdehyde and UV-B absorbing compounds, and the activity of phenylalanine ammonia lyase enzyme over the control. The contents of chlorogenic acid and flavone in flowers were significantly increased by UV-B treatments (except for UV50 and UV800). Two-dimensional gel electrophoresis was utilized to analyze proteomic changes in flowers with or without UV-B radiation. Results indicated that 43 protein spots (>1.5-fold difference in volume) were detected, including 19 spots with a decreasing trend and 24 spots with an increasing trend, and 19 differentially expressed protein spots were successfully indentified by MALDI-TOF MS. The indentified proteins were classified based on functions, the most of which were involved in photosynthesis, respiration, protein biosynthesis and degradation and defence. An overall assessment using biochemical and differential proteomic data revealed that UV-B radiation could affect biochemical reaction and promote secondary metabolism processes in postharvest flowers. Copyright © 2015 Elsevier B.V. All rights reserved.

10 CFR Appendix X to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Code of Federal Regulations, 2014 CFR

2014-01-01

... of Dehumidifiers X Appendix X to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. X Appendix X to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of...

10 CFR Appendix X to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Code of Federal Regulations, 2013 CFR

2013-01-01

... of Dehumidifiers X Appendix X to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. X Appendix X to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of...

10 CFR Appendix X to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Code of Federal Regulations, 2012 CFR

2012-01-01

... of Dehumidifiers X Appendix X to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. X Appendix X to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of...

10 CFR Appendix X to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Code of Federal Regulations, 2010 CFR

2010-01-01

... of Dehumidifiers X Appendix X to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. X Appendix X to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of...

10 CFR Appendix X to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dehumidifiers

Code of Federal Regulations, 2011 CFR

2011-01-01

... of Dehumidifiers X Appendix X to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. X Appendix X to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of...

Phospholipid transfer protein plays a major role in the initiation of apolipoprotein B-containing lipoprotein assembly in mouse primary hepatocytes.

PubMed

Manchekar, Medha; Liu, Yanwen; Sun, Zhihuan; Richardson, Paul E; Dashti, Nassrin

2015-03-27

In this study, we tested the hypothesis that phospholipid transfer protein (PLTP) is a plausible mediator of phospholipid (PL) transfer to the N-terminal 1000 residues of apoB (apoB:1000) leading to the initiation of apoB-containing lipoprotein assembly. To this end, primary hepatocytes from wild type (WT) and PLTP knock-out (KO) mice were transduced with adenovirus-apoB:1000 with or without co-transduction with adenovirus-PLTP, and the assembly and secretion of apoB:1000-containing lipoproteins were assessed. PLTP deficiency resulted in a 65 and 72% reduction in the protein and lipid content, respectively, of secreted apoB:1000-containing lipoproteins. Particles secreted by WT hepatocytes contained 69% PL, 9% diacylglycerol (DAG), and 23% triacylglycerol (TAG) with a stoichiometry of 46 PL, 6 DAG, and 15 TAG molecules per apoB:1000. PLTP absence drastically altered the lipid composition of apoB:1000 lipoproteins; these particles contained 46% PL, 13% DAG, and 41% TAG with a stoichiometry of 27 PL, 10 DAG, and 23 TAG molecules per apoB:1000. Reintroduction of Pltp gene into PLTP-KO hepatocytes stimulated the lipidation and secretion of apoB:1000-containing lipoproteins by ∼3-fold; the lipid composition and stoichiometry of these particles were identical to those secreted by WT hepatocytes. In contrast to the WT, apoB:1000 in PLTP-KO hepatocytes was susceptible to intracellular degradation predominantly in the post-endoplasmic reticulum, presecretory compartment. Reintroduction of Pltp gene into PLTP-KO hepatocytes restored the stability of apoB:1000. These results provide compelling evidence that in hepatocytes initial recruitment of PL by apoB:1000 leading to the formation of the PL-rich apoB-containing initiation complex is mediated to a large extent by PLTP. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Phospholipid Transfer Protein Plays a Major Role in the Initiation of Apolipoprotein B-containing Lipoprotein Assembly in Mouse Primary Hepatocytes*

PubMed Central

Manchekar, Medha; Liu, Yanwen; Sun, Zhihuan; Richardson, Paul E.; Dashti, Nassrin

2015-01-01

In this study, we tested the hypothesis that phospholipid transfer protein (PLTP) is a plausible mediator of phospholipid (PL) transfer to the N-terminal 1000 residues of apoB (apoB:1000) leading to the initiation of apoB-containing lipoprotein assembly. To this end, primary hepatocytes from wild type (WT) and PLTP knock-out (KO) mice were transduced with adenovirus-apoB:1000 with or without co-transduction with adenovirus-PLTP, and the assembly and secretion of apoB:1000-containing lipoproteins were assessed. PLTP deficiency resulted in a 65 and 72% reduction in the protein and lipid content, respectively, of secreted apoB:1000-containing lipoproteins. Particles secreted by WT hepatocytes contained 69% PL, 9% diacylglycerol (DAG), and 23% triacylglycerol (TAG) with a stoichiometry of 46 PL, 6 DAG, and 15 TAG molecules per apoB:1000. PLTP absence drastically altered the lipid composition of apoB:1000 lipoproteins; these particles contained 46% PL, 13% DAG, and 41% TAG with a stoichiometry of 27 PL, 10 DAG, and 23 TAG molecules per apoB:1000. Reintroduction of Pltp gene into PLTP-KO hepatocytes stimulated the lipidation and secretion of apoB:1000-containing lipoproteins by ∼3-fold; the lipid composition and stoichiometry of these particles were identical to those secreted by WT hepatocytes. In contrast to the WT, apoB:1000 in PLTP-KO hepatocytes was susceptible to intracellular degradation predominantly in the post-endoplasmic reticulum, presecretory compartment. Reintroduction of Pltp gene into PLTP-KO hepatocytes restored the stability of apoB:1000. These results provide compelling evidence that in hepatocytes initial recruitment of PL by apoB:1000 leading to the formation of the PL-rich apoB-containing initiation complex is mediated to a large extent by PLTP. PMID:25638820

Paul Hill d/b/a Alternative Energy Windows and Siding

EPA Pesticide Factsheets

Paul Hill d/b/a Alternative Energy Windows and Siding (the Company) is located in Concord, New Hampshire. The settlement involves renovation activities conducted at property constructed prior to 1978, located in Concord, New Hampshire.

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring Nominal Full Load Efficiency of Electric Motors

Code of Federal Regulations, 2013 CFR

2013-01-01

... Efficiency of Electric Motors B Appendix B to Subpart B of Part 431 Energy DEPARTMENT OF ENERGY ENERGY..., Subpt. B, App. B Appendix B to Subpart B of Part 431—Uniform Test Method for Measuring Nominal Full Load... Std 112-2004 Test Method B, Input-Output With Loss Segregation, (incorporated by reference, see § 431...

Studies of the mechanism of selectivity of protein tyrosine phosphatase 1B (PTP1B) bidentate inhibitors using molecular dynamics simulations and free energy calculations.

PubMed

Fang, Lei; Zhang, Huai; Cui, Wei; Ji, Mingjun

2008-10-01

Bidentate inhibitors of protein tyrosine phosphatase 1B (PTP1B) are considered as a group of ideal inhibitors with high binding potential and high selectivity in treating type II diabetes. In this paper, the binding models of five bidentate inhibitors to PTP1B, TCPTP, and SHP-2 were investigated and compared by using molecular dynamics (MD) simulations and free energy calculations. The binding free energies were computed using the Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) methodology. The calculation results show that the predicted free energies of the complexes are well consistent with the experimental data. The Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) free energy decomposition analysis indicates that the residues ARG24, ARG254, and GLN262 in the second binding site of PTP1B are essential for the high selectivity of inhibitors. Furthermore, the residue PHE182 close to the active site is also important for the selectivity and the binding affinity of the inhibitors. According to our analysis, it can be concluded that in most cases the polarity of the portion of the inhibitor that binds to the second binding site of the protein is positive to the affinity of the inhibitors while negative to the selectivity of the inhibitors. We expect that the information we obtained here can help to develop potential PTP1B inhibitors with more promising specificity.

B1 to B2 structural phase transition in LiF under pressure

NASA Astrophysics Data System (ADS)

Jain, Aayushi; Dixit, R. C.

2018-05-01

In the last few decades the alkali halides emerged as crystals with useful applications and their high-pressure behaviour is the most intensively studied subject in high-pressure physics/chemistry, material science, and geosciences. Most alkali halides follow the B1 (NaCl-type)→B2 (CsCl-type) phase-transition route under pressure. In the present paper, we have investigated the characteristics of structural phase transition that occurred in Lithium Florid compound under high pressure. The transition pressure of B1-B2 was calculated using an effective interionic interaction potential (EIOP). The changes of the characteristics of crystals like, Gibbs free energy, cohesive energy, volume collapse, and lattice constant are calculated for the B1 and B2 structures. These data were compared with the available experimental and theoretical data.

Binding of the B D D ¯ and B D D systems

NASA Astrophysics Data System (ADS)

Dias, J. M.; Debastiani, V. R.; Roca, L.; Sakai, S.; Oset, E.

2017-11-01

We study theoretically the B D D ¯ and B D D systems to see if they allow for possible bound or resonant states. The three-body interaction is evaluated implementing the fixed center approximation to the Faddeev equations which considers the interaction of a D or D ¯ particle with the components of a B D cluster, previously proved to form a bound state. We find an I (JP)=1 /2 (0-) bound state for the B D D ¯ system at an energy around 8925-8985 MeV within uncertainties, which would correspond to a bottom hidden-charm meson. In contrast, for the B D D system, which would be bottom double-charm and hence manifestly exotic, we have found hints of a bound state in the energy region 8935-8985 MeV, but the results are not stable under the uncertainties of the model, and we cannot assure, nor rule out, the possibility of a B D D three-body state.

Photon-tagged and B-meson-tagged b-jet production at the LHC

DOE PAGES

Huang, Jinrui; Kang, Zhong -Bo; Vitev, Ivan; ...

2015-09-18

Tagged jet measurements in high energy hadronic and nuclear reactions provide constraints on the energy and parton flavor origin of the parton shower that recoils against the tagging particle. Such additional insight can be especially beneficial in illuminating the mechanisms of heavy flavor production in proton–proton collisions at the LHC and their modification in the heavy ion environment, which are not fully understood. With this motivation, we present theoretical results for isolated-photon-tagged and B-meson-tagged b-jet production at √s NN = 5.1 TeV for comparison to the upcoming lead–lead data. We find that photon-tagged b-jets exhibit smaller momentum imbalance shift inmore » nuclear matter, and correspondingly smaller energy loss, than photon-tagged light flavor jets. Our results show that B-meson tagging is most effective in ensuring that the dominant fraction of recoiling jets originate from prompt b-quarks. Furthermore, in this channel the large suppression of the cross section is not accompanied by a significant momentum imbalance shift.« less

Bayesian Atmospheric Radiative Transfer (BART)Thermochemical Equilibrium Abundance (TEA) Code and Application to WASP-43b

NASA Astrophysics Data System (ADS)

Blecic, Jasmina; Harrington, Joseph; Bowman, Matthew O.; Cubillos, Patricio E.; Stemm, Madison; Foster, Andrew

2014-11-01

We present a new, open-source, Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. TEA uses the Gibbs-free-energy minimization method with an iterative Lagrangian optimization scheme. It initializes the radiative-transfer calculation in our Bayesian Atmospheric Radiative Transfer (BART) code. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. The code is tested against the original method developed by White at al. (1958), the analytic method developed by Burrows and Sharp (1999), and the Newton-Raphson method implemented in the open-source Chemical Equilibrium with Applications (CEA) code. TEA is written in Python and is available to the community via the open-source development site GitHub.com. We also present BART applied to eclipse depths of WASP-43b exoplanet, constraining atmospheric thermal and chemical parameters. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. JB holds a NASA Earth and Space Science Fellowship.

Quenching Capabilities of Long-Chain Carotenoids in Light-Harvesting-2 Complexes from Rhodobacter sphaeroides with an Engineered Carotenoid Synthesis Pathway

PubMed Central

2016-01-01

Six light-harvesting-2 complexes (LH2) from genetically modified strains of the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. These strains were engineered to incorporate carotenoids for which the number of conjugated groups (N = NC=C + NC=O) varies from 9 to 15. The Rb. sphaeroides strains incorporate their native carotenoids spheroidene (N = 10) and spheroidenone (N = 11), as well as longer-chain analogues including spirilloxanthin (N = 13) and diketospirilloxantion (N = 15) normally found in Rhodospirillum rubrum. Measurements of the properties of the carotenoid first singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to those in LH2 complexes from various other bacterial species and thus are not significantly impacted by differences in polypeptide composition. Instead, variations in carotenoid-to-BChl a energy transfer are primarily regulated by the N-determined energy of the carotenoid S1 excited state, which for long-chain (N ≥ 13) carotenoids is not involved in energy transfer. Furthermore, the role of the long-chain carotenoids switches from a light-harvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S1 excited state B850*. This quenching is manifested as a substantial (∼2-fold) reduction of the B850* lifetime and the B850* fluorescence quantum yield for LH2 housing the longest carotenoids. PMID:27285777

Quenching Capabilities of Long-Chain Carotenoids in Light-Harvesting-2 Complexes from Rhodobacter sphaeroides with an Engineered Carotenoid Synthesis Pathway.

PubMed

Dilbeck, Preston L; Tang, Qun; Mothersole, David J; Martin, Elizabeth C; Hunter, C Neil; Bocian, David F; Holten, Dewey; Niedzwiedzki, Dariusz M

2016-06-23

Six light-harvesting-2 complexes (LH2) from genetically modified strains of the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. These strains were engineered to incorporate carotenoids for which the number of conjugated groups (N = NC═C + NC═O) varies from 9 to 15. The Rb. sphaeroides strains incorporate their native carotenoids spheroidene (N = 10) and spheroidenone (N = 11), as well as longer-chain analogues including spirilloxanthin (N = 13) and diketospirilloxantion (N = 15) normally found in Rhodospirillum rubrum. Measurements of the properties of the carotenoid first singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to those in LH2 complexes from various other bacterial species and thus are not significantly impacted by differences in polypeptide composition. Instead, variations in carotenoid-to-BChl a energy transfer are primarily regulated by the N-determined energy of the carotenoid S1 excited state, which for long-chain (N ≥ 13) carotenoids is not involved in energy transfer. Furthermore, the role of the long-chain carotenoids switches from a light-harvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S1 excited state B850*. This quenching is manifested as a substantial (∼2-fold) reduction of the B850* lifetime and the B850* fluorescence quantum yield for LH2 housing the longest carotenoids.

AAPB-B - Committee offers revised exchange format for transferring geologic and petroleum data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waller, H.O.; Guinn, D.; Herkommer, M.

1990-04-01

Comments received since the publication of Exchange Format for Transfer of Geologic and Petroleum Data revealed the need for more flexibility with the AAPG-A Format (Shaw and Waller, 1989). This discussion resulted in the proposed AAPG-B version, which has unlimited number of data fields per record and unlimited number of records. Comment lines can appear anywhere, including in data records, to help document data transfer. Data dictionary hooks have been added. The American Petroleum Institute has assisted by supplying an ANSI envelope for this format, which will permit the electronic transfer with verification of data sets between any two ANSImore » installations. The American Association of Petroleum Geologists Database Standards Subcommittee invites comments on the proposed revisions, and will review the suggestions when it meets June 2 in San Francisco.« less

Silver Niobate Lead-Free Antiferroelectric Ceramics: Enhancing Energy Storage Density by B-Site Doping.

PubMed

Zhao, Lei; Gao, Jing; Liu, Qing; Zhang, Shujun; Li, Jing-Feng

2018-01-10

Lead-free dielectric ceramics with high recoverable energy density are highly desired to sustainably meet the future energy demand. AgNbO 3 -based lead-free antiferroelectric ceramics with double ferroelectric hysteresis loops have been proved to be potential candidates for energy storage applications. Enhanced energy storage performance with recoverable energy density of 3.3 J/cm 3 and high thermal stability with minimal energy density variation (<10%) over a temperature range of 20-120 °C have been achieved in W-modified AgNbO 3 ceramics. It is revealed that the W 6+ cations substitute the B-site Nb 5+ and reduce the polarizability of B-site cations, leading to the enhanced antiferroelectricity, which is confirmed by the polarization hysteresis and dielectric tunability. It is believed that the polarizability of B-site cations plays a dominant role in stabilizing the antiferroelectricity in AgNbO 3 system, in addition to the tolerance factor, which opens up a new design approach to achieve stable antiferroelectric materials.

C-terminal interactions mediate the quaternary dynamics of αB-crystallin

PubMed Central

Hilton, Gillian R.; Hochberg, Georg K. A.; Laganowsky, Arthur; McGinnigle, Scott I.; Baldwin, Andrew J.; Benesch, Justin L. P.

2013-01-01

αB-crystallin is a highly dynamic, polydisperse small heat-shock protein that can form oligomers ranging in mass from 200 to 800 kDa. Here we use a multifaceted mass spectrometry approach to assess the role of the C-terminal tail in the self-assembly of αB-crystallin. Titration experiments allow us to monitor the binding of peptides representing the C-terminus to the αB-crystallin core domain, and observe individual affinities to both monomeric and dimeric forms. Notably, we find that binding the second peptide equivalent to the core domain dimer is considerably more difficult than the first, suggesting a role of the C-terminus in regulating assembly. This finding motivates us to examine the effect of point mutations in the C-terminus in the full-length protein, by quantifying the changes in oligomeric distribution and corresponding subunit exchange rates. Our results combine to demonstrate that alterations in the C-terminal tail have a significant impact on the thermodynamics and kinetics of αB-crystallin. Remarkably, we find that there is energy compensation between the inter- and intra-dimer interfaces: when one interaction is weakened, the other is strengthened. This allosteric communication between binding sites on αB-crystallin is likely important for its role in binding target proteins. PMID:23530258

O2(b1Σg+) Quenching by O2, CO2, H2O, and N2 at Temperatures of 300-800 K.

PubMed

Zagidullin, M V; Khvatov, N A; Medvedkov, I A; Tolstov, G I; Mebel, A M; Heaven, M C; Azyazov, V N

2017-10-05

Rate constants for the removal of O 2 (b 1 Σ g + ) by collisions with O 2 , N 2 , CO 2 , and H 2 O have been determined over the temperature range from 297 to 800 K. O 2 (b 1 Σ g + ) was excited by pulses from a tunable dye laser, and the deactivation kinetics were followed by observing the temporal behavior of the b 1 Σ g + -X 3 Σ g - fluorescence. The removal rate constants for CO 2 , N 2 , and H 2 O were not strongly dependent on temperature and could be represented by the expressions k CO2 = (1.18 ± 0.05) × 10 -17 × T 1.5 × exp[Formula: see text], k N2 = (8 ± 0.3) × 10 -20 × T 1.5 × exp[Formula: see text], and k H2O = (1.27 ± 0.08) × 10 -16 × T 1.5 × exp[Formula: see text] cm 3 molecule -1 s -1 . Rate constants for O 2 (b 1 Σ g + ) removal by O 2 (X), being orders of magnitude lower, demonstrated a sharp increase with temperature, represented by the fitted expression k O2 = (7.4 ± 0.8) × 10 -17 × T 0.5 × exp[Formula: see text] cm 3 molecule -1 s -1 . All of the rate constants measured at room temperature were found to be in good agreement with previously reported values.

Measurement of the moments of the photon energy spectrum in B{yields}X{sub s}{gamma} decays and determination of |V{sub cb}| and m{sub b} at Belle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwanda, C.; Mandl, F.; Mitaroff, W.

2008-08-01

Using the previous Belle measurement of the inclusive photon energy in B{yields}X{sub s}{gamma} decays, we determine the first and second moments of this spectrum for minimum photon energies in the B meson rest frame ranging from 1.8 to 2.3 GeV. Combining these measurements with recent Belle data on the lepton energy and hadronic mass moments in B{yields}X{sub c}l{nu} decays, we perform fits to theoretical expressions derived in the 1S and kinetic mass schemes and extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V{sub cb}, the b-quark mass, and other nonperturbative parameters. In the 1S scheme analysis we find |V{sub cb}|=(41.56{+-}0.68(fit){+-}0.08({tau}{submore » B}))x10{sup -3} and m{sub b}{sup 1S}=(4.723{+-}0.055) GeV. In the kinetic scheme, we obtain |V{sub cb}|=(41.58{+-}0.69(fit){+-}0.08({tau}{sub B}){+-}0.58(th))x10{sup -3} and m{sub b}{sup kin}=(4.543{+-}0.075) GeV.« less

Emergence of vancomycin resistance in the genus Streptococcus: characterization of a vanB transferable determinant in Streptococcus bovis.

PubMed Central

Poyart, C; Pierre, C; Quesne, G; Pron, B; Berche, P; Trieu-Cuot, P

1997-01-01

Streptococcus bovis NEM760 was isolated from a stool swab collected on admission from a patient as surveillance for vancomycin-resistant enterococci. Strain NEM760 was identified as S. bovis by conventional biochemical methods and partial sequence analysis of its 16S rRNA. This strain was resistant to a low level of vancomycin (MIC, 64 micrograms/ml) but was susceptible to teicoplanin (MIC, 1 micrograms/ml), and vancomycin induced resistance to both glycopeptides. The presence of a vanB-related gene in NEM760 was demonstrated in a PCR assay which enabled specific amplification of a 635-hp internal segment of vanB. Sequence analysis of the corresponding PCR product revealed that it was highly homologous (96% identity) to the prototype vanB sequence of Enterococcus faecalis V583. The VanB resistance of determinant of S. bovis NEM760 was transferred by conjugation to E. faecalis and Enterococcus faecium at a similar frequency of 2 x 10(-5) per donor. SmaI-digested genomic DNAs of independently obtained transconjugants of E. faecalis and E. faecium were analyzed by pulsed-field gel electrophoresis and Southern hybridization with a vanB DNA probe. The electrophoretic and hybridization patterns obtained with all transconjugants of the same species were indistinguishable and revealed vanB-containing chromosomal insertions of approximately 100 kb. These results suggest that the genes mediating VanB-type resistance in S. bovis NEM760 are part of large transferable genetic elements. The results presented in the report demonstrate for the first time the role of streptococci in the dissemination of vancomycin resistance among gram-positive bacteria. PMID:8980749

Identifying the substrate proteins of U-box E3s E4B and CHIP by orthogonal ubiquitin transfer.

PubMed

Bhuripanyo, Karan; Wang, Yiyang; Liu, Xianpeng; Zhou, Li; Liu, Ruochuan; Duong, Duc; Zhao, Bo; Bi, Yingtao; Zhou, Han; Chen, Geng; Seyfried, Nicholas T; Chazin, Walter J; Kiyokawa, Hiroaki; Yin, Jun

2018-01-01

E3 ubiquitin (UB) ligases E4B and carboxyl terminus of Hsc70-interacting protein (CHIP) use a common U-box motif to transfer UB from E1 and E2 enzymes to their substrate proteins and regulate diverse cellular processes. To profile their ubiquitination targets in the cell, we used phage display to engineer E2-E4B and E2-CHIP pairs that were free of cross-reactivity with the native UB transfer cascades. We then used the engineered E2-E3 pairs to construct "orthogonal UB transfer (OUT)" cascades so that a mutant UB (xUB) could be exclusively used by the engineered E4B or CHIP to label their substrate proteins. Purification of xUB-conjugated proteins followed by proteomics analysis enabled the identification of hundreds of potential substrates of E4B and CHIP in human embryonic kidney 293 cells. Kinase MAPK3 (mitogen-activated protein kinase 3), methyltransferase PRMT1 (protein arginine N -methyltransferase 1), and phosphatase PPP3CA (protein phosphatase 3 catalytic subunit alpha) were identified as the shared substrates of the two E3s. Phosphatase PGAM5 (phosphoglycerate mutase 5) and deubiquitinase OTUB1 (ovarian tumor domain containing ubiquitin aldehyde binding protein 1) were confirmed as E4B substrates, and β-catenin and CDK4 (cyclin-dependent kinase 4) were confirmed as CHIP substrates. On the basis of the CHIP-CDK4 circuit identified by OUT, we revealed that CHIP signals CDK4 degradation in response to endoplasmic reticulum stress.

Identifying the substrate proteins of U-box E3s E4B and CHIP by orthogonal ubiquitin transfer

PubMed Central

Bhuripanyo, Karan; Wang, Yiyang; Liu, Xianpeng; Zhou, Li; Liu, Ruochuan; Duong, Duc; Zhao, Bo; Bi, Yingtao; Zhou, Han; Chen, Geng; Seyfried, Nicholas T.; Chazin, Walter J.; Kiyokawa, Hiroaki; Yin, Jun

2018-01-01

E3 ubiquitin (UB) ligases E4B and carboxyl terminus of Hsc70-interacting protein (CHIP) use a common U-box motif to transfer UB from E1 and E2 enzymes to their substrate proteins and regulate diverse cellular processes. To profile their ubiquitination targets in the cell, we used phage display to engineer E2-E4B and E2-CHIP pairs that were free of cross-reactivity with the native UB transfer cascades. We then used the engineered E2-E3 pairs to construct “orthogonal UB transfer (OUT)” cascades so that a mutant UB (xUB) could be exclusively used by the engineered E4B or CHIP to label their substrate proteins. Purification of xUB-conjugated proteins followed by proteomics analysis enabled the identification of hundreds of potential substrates of E4B and CHIP in human embryonic kidney 293 cells. Kinase MAPK3 (mitogen-activated protein kinase 3), methyltransferase PRMT1 (protein arginine N-methyltransferase 1), and phosphatase PPP3CA (protein phosphatase 3 catalytic subunit alpha) were identified as the shared substrates of the two E3s. Phosphatase PGAM5 (phosphoglycerate mutase 5) and deubiquitinase OTUB1 (ovarian tumor domain containing ubiquitin aldehyde binding protein 1) were confirmed as E4B substrates, and β-catenin and CDK4 (cyclin-dependent kinase 4) were confirmed as CHIP substrates. On the basis of the CHIP-CDK4 circuit identified by OUT, we revealed that CHIP signals CDK4 degradation in response to endoplasmic reticulum stress. PMID:29326975

Coherence, Energy and Charge Transfers in De-Excitation Pathways of Electronic Excited State of Biomolecules in Photosynthesis

NASA Astrophysics Data System (ADS)

Bohr, Henrik G.; Malik, F. Bary

2013-11-01

The observed multiple de-excitation pathways of photo-absorbed electronic excited state in the peridinin-chlorophyll complex, involving both energy and charge transfers among its constituents, are analyzed using the bio-Auger (B-A) theory. It is also shown that the usually used Förster-Dexter theory, which does not allow for charge transfer, is a special case of B-A theory. The latter could, under appropriate circumstances, lead to excimers.

Calibration of the ``Simplified Simple Biosphere Model—SSiB'' for the Brazilian Northeast Caatinga

NASA Astrophysics Data System (ADS)

do Amaral Cunha, Ana Paula Martins; dos Santos Alvalá, Regina Célia; Correia, Francis Wagner Silva; Kubota, Paulo Yoshio

2009-03-01

The Brazilian Northeast region is covered largely by vegetation adapted to the arid conditions and with varied physiognomy, called caatinga. It occupies an extension of about 800.000 km2 that corresponds to 70% of the region. In recent decades, considerable progress in understanding the micrometeorological processes has been reached, with results that were incorporated into soil-vegetation-atmosphere transfer schemes (SVATS) to study the momentum, energy, water vapor, carbon cycle and vegetation dynamics changes of different ecosystems. Notwithstanding, the knowledge of the parameters and physical or physiological characteristics of the vegetation and soil of the caatinga region is very scarce. So, the objective of this work was performing a calibration of the parameters of the SSiB model for the Brazilian Northeast Caatinga. Micrometeorological and hydrological data collected from July 2004 to June 2005, obtained in the Agricultural Research Center of the Semi-Arid Tropic (CPATSA), were used. Preceding the calibration process, a sensibility study of the SSiB model was performed in order to find the parameters that are sensible to the exchange processes between the surface and atmosphere. The results showed that the B parameter, soil moisture potential at saturation (ψs), hydraulic conductivity of saturated soil (ks) and the volumetric moisture at saturation (θs) present high variations on turbulent fluxes. With the initial parameters, the SSiB model showed best results for net radiation, and the latent heat (sensible heat) flux was over-estimated (under-estimated) for all simulation periods. Considering the calibrated parameters, better values of latent flux and sensible flux were obtained. The calibrated parameters were also used for a validation of the surface fluxes considering data from July 2005 to September 2005. The results showed that the model generated better estimations of latent heat and sensible heat fluxes, with low root mean square error. With

Theoretical investigation on the potential energy surface for the reactions of B, Al and Ga with NO

NASA Astrophysics Data System (ADS)

Zhang, Luning; Zhou, Mingfei

2000-06-01

The structures, binding energies and vibrational frequencies of various MNO structural isomers (M=B, Al and Ga) in their ground triplet states have been determined using the density functional (B3LYP, BP86 and B3PW91) and MP2 methods. The potential energy surfaces of the M+NO reactions have been developed at the B3LYP/6-311+G(d) level of theory, and transition states on the isomerization potential energy surfaces have been characterized. Our calculation results show that four BNO isomers, namely, nitrosyl BNO, isonitrosyl BON, side-bonded B- η2-NO and the inserted NBO molecules are stationary points, while for Al and Ga, only the MNO (nitrosyl), MON (isonitrosyl) and the OMN (insertion) molecules are local minimum. The B+NO reaction products are more strongly bonded compared to the Al and Ga+NO systems due to strong covalent bonding. The interactions of B, Al and Ga atoms with NO to generate nitrosyl and isonitrosyl addition molecules are barrierless, but subsequent isomerization reactions to form the side-bonded molecules and the inserted products require activation energy.

Surprising Rapid Collapse of Sirius B from Red Giant to White Dwarf Through Mass Transfer to Sirius a

NASA Astrophysics Data System (ADS)

Yousef, Shahinaz; Ali, Ola

2013-03-01

Sirius was observed in antiquity as a red star. In his famous astronomy textbook the Almagest written 140 AD, Ptolemy described the star Sirius as fiery red. He curiously depicted it as one of six red-colored stars. The other five are class M and K stars, such as Arcturus and Betelgeuse. Apparent confirmation in ancient Greek and Roman sources are found and Sirius was also reported red in Europe about 1400 years ago. Sirius must have changed to a white dwarf in the night of Ascension. The star chapter in the Quran started with "by the star as it collapsed (1) your companion have not gone astray nor being misled (2), and in verse 49 which is the rotation period of the companion Sirius B around Sirius A, it is said" He is the Lord of Sirius (49). If Sirius actually was red what could have caused it to change into the brilliant bluish-white star we see today? What the naked eye perceives as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The red color indicates that the star seen then was a red giant. It looks that what they have seen in antiquity was Sirius B which was then a red giant and it collapsed to form a white dwarf. Since there is no evidence of a planetary nebula, then the red Sirius paradox can be solved in terms of stellar evolution with mass transfer. Sirius B was the most massive star which evolved to a red giant and filled the Roche lobe. Mass transfer to Sirius A occurred through the Lagrangian point. Sirius A then became more massive while Sirius B lost mass and shrank. Sirius B then collapsed abruptly into a white dwarf. In the case of Algol, Ptolmy observed it as white star but it was red at the time of El sufi. At present it is white. The rate of mass transfer from Sirius B to Sirius A, and from Algol B to A is estimated from observational data of colour change from red to bullish white to be 0

Joining sheet aluminum AA6061-T4 to cast magnesium AM60B by vaporizing foil actuator welding: Input energy, interface, and strength

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Bert; Vivek, Anupam; Daehn, Glenn S.

Dissimilar joining of sheet aluminum AA6061-T4 to cast magnesium AM60B was achieved by vaporizing foil actuator welding (VFAW). Three input energy levels were used (6, 8, and 10 kJ), and as a trend, higher input energies resulted in progressively higher flyer velocities, more pronounced interfacial wavy features, larger weld zones, higher peel strengths, and higher peel energies. In all cases, weld cross section revealed a soundly bonded interface characterized by well-developed wavy features and lack of voids and continuous layers of intermetallic compounds (IMCs). At 10 kJ input energy, flyer speed of 820 m/s, peel strength of 22.4 N/mm, andmore » peel energy of 5.2 J were obtained. In lap-shear, failure occurred in AA6061- T4 flyer at 97% of the base material’s peak tensile load. Peel samples failed along the weld interface, and the AM60B-side of the fracture surface showed thin, evenly-spaced lines of Al residuals which had been torn out of the base AA6061-T4 in a ductile fashion and transferred over to the AM60B side, indicating very strong AA6061-T4/AM60B bond in these areas. Furthermore, this work demonstrates VFAW’s capability in joining dissimilar lightweight metals such as Al/Mg, which is expected to be a great enabler in the ongoing push for vehicle weight reduction.« less

Joining sheet aluminum AA6061-T4 to cast magnesium AM60B by vaporizing foil actuator welding: Input energy, interface, and strength

DOE PAGES

Liu, Bert; Vivek, Anupam; Daehn, Glenn S.

2017-09-19

Dissimilar joining of sheet aluminum AA6061-T4 to cast magnesium AM60B was achieved by vaporizing foil actuator welding (VFAW). Three input energy levels were used (6, 8, and 10 kJ), and as a trend, higher input energies resulted in progressively higher flyer velocities, more pronounced interfacial wavy features, larger weld zones, higher peel strengths, and higher peel energies. In all cases, weld cross section revealed a soundly bonded interface characterized by well-developed wavy features and lack of voids and continuous layers of intermetallic compounds (IMCs). At 10 kJ input energy, flyer speed of 820 m/s, peel strength of 22.4 N/mm, andmore » peel energy of 5.2 J were obtained. In lap-shear, failure occurred in AA6061- T4 flyer at 97% of the base material’s peak tensile load. Peel samples failed along the weld interface, and the AM60B-side of the fracture surface showed thin, evenly-spaced lines of Al residuals which had been torn out of the base AA6061-T4 in a ductile fashion and transferred over to the AM60B side, indicating very strong AA6061-T4/AM60B bond in these areas. Furthermore, this work demonstrates VFAW’s capability in joining dissimilar lightweight metals such as Al/Mg, which is expected to be a great enabler in the ongoing push for vehicle weight reduction.« less

Silyl Ketene Acetals/B(C₆F₅)₃ Lewis Pair-Catalyzed Living Group Transfer Polymerization of Renewable Cyclic Acrylic Monomers.

PubMed

Hu, Lu; Zhao, Wuchao; He, Jianghua; Zhang, Yuetao

2018-03-15

This work reveals the silyl ketene acetal (SKA)/B(C₆F₅)₃ Lewis pair-catalyzed room-temperature group transfer polymerization (GTP) of polar acrylic monomers, including methyl linear methacrylate (MMA), and the biorenewable cyclic monomers γ-methyl-α-methylene-γ-butyrolactone (MMBL) and α-methylene-γ-butyrolactone (MBL) as well. The in situ NMR monitored reaction of SKA with B(C₆F₅)₃ indicated the formation of Frustrated Lewis Pairs (FLPs), although it is sluggish for MMA polymerization, such a FLP system exhibits highly activity and living GTP of MMBL and MBL. Detailed investigations, including the characterization of key reaction intermediates, polymerization kinetics and polymer structures have led to a polymerization mechanism, in which the polymerization is initiated with an intermolecular Michael addition of the ester enolate group of SKA to the vinyl group of B(C₆F₅)₃-activated monomer, while the silyl group is transferred to the carbonyl group of the B(C₆F₅)₃-activated monomer to generate the single-monomer-addition species or the active propagating species; the coordinated B(C₆F₅)₃ is released to the incoming monomer, followed by repeated intermolecular Michael additions in the subsequent propagation cycle. Such neutral SKA analogues are the real active species for the polymerization and are retained in the whole process as confirmed by experimental data and the chain-end analysis by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). Moreover, using this method, we have successfully synthesized well-defined PMMBL- b -PMBL, PMMBL- b -PMBL- b -PMMBL and random copolymers with the predicated molecular weights ( M n ) and narrow molecular weight distribution (MWD).

[In vitro study of vitamins B1, B2 and B6 adsorption on zeolite].

PubMed

Basić, Zorica; Kilibarda, Vesna; Dobrić, Silva; Resanović, Radmila

2011-01-01

Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitiveness). The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7), concentration of vitamin solution (1, 2 and 5 mg/L), the length of contact with zeolite (10-180 min) and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37 degrees C. Jon competitiveness was examined by adding commercial feed mixture (grower) with a defined content of the examined vitamins in zeolite solutions the pH = 2 and pH = 7. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37 degrees C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations tests. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed vitamins after 30 min of extraction

Neuronal SH2B1 is essential for controlling energy and glucose homeostasis.

PubMed

Ren, Decheng; Zhou, Yingjiang; Morris, David; Li, Minghua; Li, Zhiqin; Rui, Liangyou

2007-02-01

SH2B1 (previously named SH2-B), a cytoplasmic adaptor protein, binds via its Src homology 2 (SH2) domain to a variety of protein tyrosine kinases, including JAK2 and the insulin receptor. SH2B1-deficient mice are obese and diabetic. Here we demonstrated that multiple isoforms of SH2B1 (alpha, beta, gamma, and/or delta) were expressed in numerous tissues, including the brain, hypothalamus, liver, muscle, adipose tissue, heart, and pancreas. Rat SH2B1beta was specifically expressed in neural tissue in SH2B1-transgenic (SH2B1(Tg)) mice. SH2B1(Tg) mice were crossed with SH2B1-knockout (SH2B1(KO)) mice to generate SH2B1(TgKO) mice expressing SH2B1 only in neural tissue but not in other tissues. Systemic deletion of the SH2B1 gene resulted in metabolic disorders in SH2B1(KO) mice, including hyperlipidemia, leptin resistance, hyperphagia, obesity, hyperglycemia, insulin resistance, and glucose intolerance. Neuron-specific restoration of SH2B1beta not only corrected the metabolic disorders in SH2B1(TgKO) mice, but also improved JAK2-mediated leptin signaling and leptin regulation of orexigenic neuropeptide expression in the hypothalamus. Moreover, neuron-specific overexpression of SH2B1 dose-dependently protected against high-fat diet-induced leptin resistance and obesity. These observations suggest that neuronal SH2B1 regulates energy balance, body weight, peripheral insulin sensitivity, and glucose homeostasis at least in part by enhancing hypothalamic leptin sensitivity.

Collective Förster energy transfer modified by planar plasmonic mirror (Presentation Recording)

NASA Astrophysics Data System (ADS)

Poddubny, Alexander N.

2015-09-01

This is an invited presentation devoted to the Förster energy transfer in plasmonic systems. Förster energy transfer processes are now actively studied in various fields that bridge physics, biology and medicine. One can try to control the efficiency of the transfer by embedding the donors and acceptors into the structured electromagnetic environment. Available experimental studies yields contradictory reports on suppressed [1], enhanced [2] or unaffected [3] transfer. We present a rigorous Green function theory of the collective Förster energy transfer between the arrays of donor and acceptor molecules lying on the planar metallic mirror that has been previously available only for spherical nanoparticles [4]. We reveal strong modification of the effective transfer rate by the mirror. The rate can be either suppressed or enhanced depending on the relative positions between acceptor and donor arrays. This is a collective effect, completely absent for a single donor-acceptor pair put above the mirror. Our results may explain the slowdown of the transfer rate recently observed in experiment for dye molecules put on top of plasmonic mirrors and layered hyperbolic metamaterials [1]. [1] T. Tumkur, J. Kitur, C. Bonner, A. Poddubny, E. Narimanov and M. Noginov , Faraday Discuss., 2014 , DOI: 10.1039/C4FD00184B [2] C. Blum, N. Zijlstra, A. Lagendijk, M. Wubs, A. P. Mosk, V. Subramaniam, and W. L. Vos, Phys. Rev. Lett. 109, 203601 (2012). [3] P. Andrew and W. L. Barnes, Science 290, 785 (2000). [4] V.N. Pustovit, A.M. Urbas, and T.V. Shahbazyan, Phys. Rev. B 88, 245427(2013)

Asymmetric angular dependence of spin-transfer torques in CoFe/Mg-B-O/CoFe magnetic tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Ling, E-mail: lingtang@zjut.edu.cn; Xu, Zhi-Jun, E-mail: xzj@zjut.edu.cn; Zuo, Xian-Jun

Using a first-principles noncollinear wave-function-matching method, we studied the spin-transfer torques (STTs) in CoFe/Mg-B-O/CoFe(001) magnetic tunnel junctions (MTJs), where three different types of B-doped MgO in the spacer are considered, including B atoms replacing Mg atoms (Mg{sub 3}BO{sub 4}), B atoms replacing O atoms (Mg{sub 4}BO{sub 3}), and B atoms occupying interstitial positions (Mg{sub 4}BO{sub 4}) in MgO. A strong asymmetric angular dependence of STT can be obtained both in ballistic CoFe/Mg{sub 3}BO{sub 4} and CoFe/Mg{sub 4}BO{sub 4} based MTJs, whereas a nearly symmetric STT curve is observed in the junctions based on CoFe/Mg{sub 4}BO{sub 3}. Furthermore, the asymmetry ofmore » the angular dependence of STT can be suppressed significantly by the disorder of B distribution. Such skewness of STTs in the CoFe/Mg-B-O/CoFe MTJs could be attributed to the interfacial resonance states induced by the B diffusion into MgO spacer.« less

Direct involvement of ombB, omaB, and omcB genes in extracellular reduction of Fe(III) by Geobacter sulfurreducens PCA

DOE PAGES

Liu, Yimo; Fredrickson, Jim K.; Zachara, John M.; ...

2015-10-01

The tandem gene clusters orfR-ombB-omaB-omcB and orfS-ombC-omaC-omcC of the metal-reducing bacterium Geobacter sulfurreducens PCA are responsible for trans-outer membrane electron transfer during extracellular reduction of Fe(III)-citrate and ferrihydrite [a poorly crystalline Fe(III) oxide]. Each gene cluster encodes a putative transcriptional factor (OrfR/OrfS), a porin-like outer-membrane protein (OmbB/OmbC), a periplasmic c-type cytochrome (c-Cyt, OmaB/OmaC) and an outer-membrane c-Cyt (OmcB/OmcC). The individual roles of OmbB, OmaB and OmcB in extracellular reduction of Fe(III), however, have remained either uninvestigated or controversial. Here, we showed that replacements of ombB, omaB, omcB and ombB-omaB with an antibiotic gene in the presence of ombC-omaC-omcC had nomore » impact on reduction of Fe(III)-citrate by G. sulfurreducens PCA. Disruption of ombB, omaB, omcB and ombB-omaB in the absence of ombC-omaC-omcC, however, severely impaired the bacterial ability to reduce Fe(III)-citrate as well as ferrihydrite. These results unequivocally demonstrate an overlapping role of ombB-omaB-omcB and ombC-omaC-omcC in extracellular Fe(III) reduction by G. sulfurreducens PCA. Involvement of both ombB-omaB-omcB and ombC-omaC-omcC in extracellular Fe(III) reduction reflects the importance of these trans-outer membrane protein complexes in the physiology of this bacterium. Moreover, the kinetics of Fe(III)-citrate and ferrihydrite reduction by these mutants in the absence of ombC-omaC-omcC were nearly identical, which clearly show that OmbB, OmaB and OmcB contribute equally to extracellular Fe(III) reduction. Finally, orfS was found to have a negative impact on the extracellular reduction of Fe(III)-citrate and ferrihydrite in G. sulfurreducens PCA probably by serving as a transcriptional repressor.« less

The CVD ZrB2 as a selective solar absorber

NASA Astrophysics Data System (ADS)

Randich, E.; Allred, D. D.

Coatings of ZrB2 and TiB2 for photothermal solar absorber applications were prepared using chemical vapor deposition (CVD) techniques. Oxidation tests suggest a maximum temperature limit for air exposure of 600 K for TiB2 and 800 K for Z4B2. Both materials exhibit innate spectral selectivity with emittance at 375 K ranging from 0.06 to 0.09 and solar absorptance for ZrB2 ranging from 0.67 to 0.77 and solar absorptance for TiB2 ranging from 0.46 to 0.58. ZrB2 has better solar selectivity and more desirable oxidation behavior than TiB2. A 0.071 micrometer antireflection coating of Si3N4 deposited on the ZrB2 coating leads to an increase in absorptance from 0.77 to 0.93, while the emittance remains unchanged.

21 CFR 522.800 - Droperidol and fentanyl.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Droperidol and fentanyl. 522.800 Section 522.800... Droperidol and fentanyl. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) of droperidol and 0.4 mg of fentanyl citrate. (b) Sponsor. See No. 000061 in § 510.600(c) of this chapter. (c...

10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program Informed...

10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program Informed...

10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program Informed...

10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program Informed...

10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program Informed...

ENDF/B-THERMOS; 30-group ENDF/B scattering kernels. [Auxiliary program written in FORTRAN IV

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrosson, F.J.; Finch, D.R.

These data are 30-group THERMOS thermal scattering kernels for P0 to P5 Legendre orders for every temperature of every material from s(alpha,beta) data stored in the ENDF/B library. These scattering kernels were generated using the FLANGE2 computer code. To test the kernels, the integral properties of each set of kernels were determined by a precision integration of the diffusion length equation and compared to experimental measurements of these properties. In general, the agreement was very good. Details of the methods used and results obtained are contained in the reference. The scattering kernels are organized into a two volume magnetic tapemore » library from which they may be retrieved easily for use in any 30-group THERMOS library. The contents of the tapes are as follows - VOLUME I Material ZA Temperatures (degrees K) Molecular H2O 100.0 296, 350, 400, 450, 500, 600, 800, 1000 Molecular D2O 101.0 296, 350, 400, 450, 500, 600, 800, 1000 Graphite 6000.0 296, 400, 500, 600, 700, 800, 1000, 1200, 1600, 2000 Polyethylene 205.0 296, 350 Benzene 106.0 296, 350, 400, 450, 500, 600, 800, 1000 VOLUME II Material ZA Temperatures (degrees K) Zr bound in ZrHx 203.0 296, 400, 500, 600, 700, 800, 1000, 1200 H bound in ZrHx 230.0 296, 400, 500, 600, 700, 800, 1000, 1200 Beryllium-9 4009.0 296, 400, 500, 600, 700, 800, 1000, 1200 Beryllium Oxide 200.0 296, 400, 500, 600, 700, 800, 1000, 1200 Uranium Dioxide 207.0 296, 400, 500, 600, 700, 800, 1000, 1200Auxiliary program written in FORTRAN IV; The retrieval program requires 1 tape drive and a small amount of high-speed core.« less

14 CFR 1203.800 - Delegations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Secret and Confidential security classification assignments to information under their jurisdiction for... Information. (2) SECRET and CONFIDENTIAL Classification Authority. Officials listed in paragraph (b)(1) of... Authority To Make Determinations in Original Classification Matters § 1203.800 Delegations. (a) The NASA...

14 CFR 1203.800 - Delegations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Secret and Confidential security classification assignments to information under their jurisdiction for... Information. (2) SECRET and CONFIDENTIAL Classification Authority. Officials listed in paragraph (b)(1) of... Authority To Make Determinations in Original Classification Matters § 1203.800 Delegations. (a) The NASA...

Impact of scalar mesons on the rare B-decays

NASA Astrophysics Data System (ADS)

Issadykov, Aidos; Ivanov, Mikhail A.; Sakhiyev, Sayabek K.

2015-11-01

In the wake of exploring uncertainty in the full angular distribution of the B → Kπ + μ+μ- caused by the presence of the intermediate scalar K0∗ meson, we perform the straightforward calculation of the B(Bs) → S (S is a scalar meson) transition form factors in the full kinematical region within the covariant quark model. We restrict ourselves by the scalar mesons below 1 GeV: a0(980),f0(500),f0(980),K0∗(800). As an application of the obtained results we calculate the widths of the semileptonic and rare decays B(Bs) → Sℓν¯, B(Bs) → Sℓℓ¯ and B(Bs) → Sνν¯. We compare our results with those obtained in other approaches.

Dynamic docking and electron transfer between Zn-myoglobin and cytochrome b(5).

PubMed

Liang, Zhao-Xun; Nocek, Judith M; Huang, Kai; Hayes, Ryan T; Kurnikov, Igor V; Beratan, David N; Hoffman, Brian M

2002-06-19

We present a broad study of the effect of neutralizing the two negative charges of the Mb propionates on the interaction and electron transfer (ET) between horse Mb and bovine cyt b(5), through use of Zn-substituted Mb (ZnMb, 1) to study the photoinitiated reaction, ((3)ZnP)Mb + Fe(3+)cyt b(5) --> (ZnP)(+)Mb + Fe(2+)cyt b(5). The charge neutralization has been carried out both by replacing the Mb heme with zinc-deuteroporphyrin dimethylester (ZnMb(dme), 2), which replaces the charges by small neutral hydrophobic patches, and also by replacement with the newly prepared zinc-deuteroporphyrin diamide (ZnMb(diamide), 3), which converts the charged groups to neutral, hydrophilic ones. The effect of propionate neutralization on the conformation of the zinc-porphyrin in the Mb heme pocket has been studied by multinuclear NMR with an (15)N labeled zinc porphyrin derivative (ZnMb((15)N-diamide), 4). The rates of photoinitiated ET between the Mb's (1-3) and cyt b(5) have been measured over a range of pH values and ionic strengths. Isothermal titration calorimetry (ITC) and NMR methods have been used to independently investigate the effect of charge neutralization on Mb/b(5) binding. The neutralization of the two heme propionates of ZnMb by formation of the heme diester or, for the first time, the diamide increases the second-order rate constant of the ET reaction between ZnMb and cyt b(5) by as much as several 100-fold, depending on pH and ionic strength, while causing negligible changes in binding affinity. Brownian dynamic (BD) simulations and ET pathway calculations provide insight into the protein docking and ET process. The results support a new "dynamic docking" paradigm for protein-protein reactions in which numerous weakly bound conformations of the docked complex contribute to the binding of cyt b(5) to Mb and Hb, but only a very small subset of these are ET active, and this subset does not include the conformations most favorable for binding; the Mb surface is a

[Enniatin B synthesis by a Fusarium sambucinum Fuck culture].

PubMed

Minasian, A E; Chermenskiĭ, D N; Ellanskaia, I A

1978-01-01

Three fungal strains belonging to the genus Fusarium Lk. ex. Fr. (F. sambucinum Fuck. 52377, F. avenaceum (Fr. Sacc.) 52311, F. gibbosum App. et. Wr. emend Bilai 52021) whcih form 800-1200 mg of enniatin B per litre during submerged cultivation have been selected. The morphology of F. sambucinum 52377 in the course of growth and production of enniatin B on the selected medium is described. The maximum accumulation of the product is found at the stationary growth phase. The active accumulation of fatty inclusions during this period suggests the participation of metabolism of fatty acids in the biosynthesis of enniatin B.

10 CFR Appendix E to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Water Heaters

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Uniform Test Method for Measuring the Energy Consumption of Water Heaters E Appendix E to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. E Appendix E to Subpart B of Part 430—Uniform Test Method...

On the enhancement of p-11B fusion reaction rate in laser-driven plasma by α → p collisional energy transfer

NASA Astrophysics Data System (ADS)

Belloni, Fabio; Margarone, Daniele; Picciotto, Antonino; Schillaci, Francesco; Giuffrida, Lorenzo

2018-02-01

The possibility of triggering an avalanche reaction in laser-driven p-11B fusion by the effect of collisional energy transfer from α particles to protons has recently been debated, especially in connection to the high yield of α particles (4 × 108 per laser shot) achieved on engineered targets at the Prague Asterix Laser System (PALS), with a pulse of 500 J, 0.3 ns FWHM. We elucidate this controversial subject within the framework of a simple two-population model for protons, based on the binary collision theory in a plasma. We find an avalanche characteristic time of almost 1 μs for the 675 keV fusion cross section resonance in typical PALS plasma, upon idealized confinement conditions. This avalanche time is one order of magnitude higher than previously reported, meaning that no such process can substantially develop in plasma at the PALS on the 675 keV resonance, not even in the most optimistic confinement scenarios. Nevertheless, we put forward for further investigation that more realistic conditions for setting up the avalanche regime could rather be attained by suitably targeting the narrow 163 keV resonance in the fusion cross section, also in connection to recently proposed laser-driven magnetic trapping techniques.

High yield of secondary B-side electron transfer in mutant Rhodobacter capsulatus reaction centers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kressel, Lucas; Faries, Kaitlyn M.; Wander, Marc J.

2014-08-01

From the crystal structures of reaction centers (RCs) from purple photosynthetic bacteria, two pathways for electron transfer (ET) are apparent but only one pathway (the A side) operates in the native protein-cofactor complex. Partial activation of the B-side pathway has unveiled the true inefficiencies of ET processes on that side in comparison to analogous reactions on the A side. Of significance are the relative rate constants for forward ET and the competing charge recombination reactions. On the B side, these rate constants are nearly equal for the secondary charge-separation step (ET from bacteriopheophytin to quinone), relegating the yield of thismore » process to < 50%. Herein we report efforts to optimize this step. In surveying all possible residues at position 131 in the M subunit, we discovered that when glutamic acid replaces the native valine the efficiency of the secondary ET is nearly two-fold higher than in the wild-type RC. The positive effect of M131 Glu is likely due to formation of a hydrogen bond with the ring V keto group of the B-side bacteriopheophytin leading to stabilization of the charge-separated state involving this cofactor. In conclusion, this change slows charge recombination by roughly a factor of two and affords the improved yield of the desired forward ET to the B-side quinone terminal acceptor.« less

Curcumin Regulates Low-Linear Energy Transfer {gamma}-Radiation-Induced NF{kappa}B-Dependent Telomerase Activity in Human Neuroblastoma Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aravindan, Natarajan, E-mail: naravind@ouhsc.ed; Veeraraghavan, Jamunarani; Madhusoodhanan, Rakhesh

2011-03-15

Purpose: We recently reported that curcumin attenuates ionizing radiation (IR)-induced survival signaling and proliferation in human neuroblastoma cells. Also, in the endothelial system, we have demonstrated that NF{kappa}B regulates IR-induced telomerase activity (TA). Accordingly, we investigated the effect of curcumin in inhibiting IR-induced NF{kappa}B-dependent hTERT transcription, TA, and cell survival in neuroblastoma cells. Methods and Materials: SK-N-MC or SH-SY5Y cells exposed to IR and treated with curcumin (10-100 nM) with or without IR were harvested after 1 h through 24 h. NF{kappa}B-dependent regulation was investigated either by luciferase reporter assays using pNF{kappa}B-, pGL3-354-, pGL3-347-, or pUSE-I{kappa}B{alpha}-Luc, p50/p65, or RelA siRNA-transfectedmore » cells. NF{kappa}B activity was analyzed using an electrophoretic mobility shift assay and hTERT expression using the quantitative polymerase chain reaction. TA was determined using the telomerase repeat amplification protocol assay and cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide and clonogenic assay. Results: Curcumin profoundly inhibited IR-induced NF{kappa}B. Consequently, curcumin significantly inhibited IR-induced TA and hTERT mRNA at all points investigated. Furthermore, IR-induced TA is regulated at the transcriptional level by triggering telomerase reverse transcriptase (TERT) promoter activation. Moreover, NF{kappa}B becomes functionally activated after IR and mediates TA upregulation by binding to the {kappa}B-binding region in the promoter region of the TERT gene. Consistently, elimination of the NF{kappa}B-recognition site on the telomerase promoter or inhibition of NF{kappa}B by the I{kappa}B{alpha} mutant compromises IR-induced telomerase promoter activation. Significantly, curcumin inhibited IR-induced TERT transcription. Consequently, curcumin inhibited hTERT mRNA and TA in NF{kappa}B overexpressed cells. Furthermore, curcumin

A Multiple Scattering Polarized Radiative Transfer Model: Application to HD 189733b

NASA Astrophysics Data System (ADS)

Kopparla, Pushkar; Natraj, Vijay; Zhang, Xi; Swain, Mark R.; Wiktorowicz, Sloane J.; Yung, Yuk L.

2016-01-01

We present a multiple scattering vector radiative transfer model that produces disk integrated, full phase polarized light curves for reflected light from an exoplanetary atmosphere. We validate our model against results from published analytical and computational models and discuss a small number of cases relevant to the existing and possible near-future observations of the exoplanet HD 189733b. HD 189733b is arguably the most well observed exoplanet to date and the only exoplanet to be observed in polarized light, yet it is debated if the planet’s atmosphere is cloudy or clear. We model reflected light from clear atmospheres with Rayleigh scattering, and cloudy or hazy atmospheres with Mie and fractal aggregate particles. We show that clear and cloudy atmospheres have large differences in polarized light as compared to simple flux measurements, though existing observations are insufficient to make this distinction. Futhermore, we show that atmospheres that are spatially inhomogeneous, such as being partially covered by clouds or hazes, exhibit larger contrasts in polarized light when compared to clear atmospheres. This effect can potentially be used to identify patchy clouds in exoplanets. Given a set of full phase polarimetric measurements, this model can constrain the geometric albedo, properties of scattering particles in the atmosphere, and the longitude of the ascending node of the orbit. The model is used to interpret new polarimetric observations of HD 189733b in a companion paper.

[Vitamin B12 deficiency associated with high doses od metformin in older people diabetic].

PubMed

Sánchez, Hugo; Masferrer, Dominique; Lera, Lydia; Arancibia, Estrella; Angel, Barbara; Albala, Cecilia

2014-06-01

The aim of the study was to estimate if B12 deficiency is associated with the use of metformin in the elderly diabetics. Case-control study in diabetic OP. Cases (n = 137) were defined as elderly with B12 < 221 pmol/L and controls (n = 279) elderly with B12 > 221 pmol/L. Four categories of metformin use were defined: non-users, ≤850 mg/day, > 850 and < 2,550 mg/day and ≥2,550 mg/day. Metformin ≥2,550 mg/day was high doses considered. The crude OR for B12 deficiency and consumption of Metformin were calculated. Logistic regression models were developed to explore the association between B12 deficiency and metformin dose. The research protocol was approved by the Ethics Committee of INTA. The age of cases and controls was (70.2 years vs 68.6 years (p < 0.05). The 62% were women in cases vs 74.9% in controls (p < 0.05). The 73% of cases and 76% of controls used metformin (p < 0.05) the average consumption of metformin was de 1,954.3 mg/day (SD: 1,063.2) in cases and 1,696.6 mg/day (SD: 1,074.4) in controls (p < 0.05). The use of 2,550 mg/day was observed in 29.2% of cases and 19.3% for controls (p < 0.05). It was observed that OP who consumed high doses of metformin had 1.9 times the risk of B12 deficiency (OR: 1.9; 95%CI: 1,08- 3,30). These results show a strong association between high doses of metformin and low levels of vitamin B12 in diabetic elderly. This project was funded by FONIS SA11I2092. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Theoretical and experimental evidence for a nodal energy gap in MgB2

NASA Astrophysics Data System (ADS)

Agassi, Y. Dan; Oates, Daniel E.

2017-11-01

We present a phenomenological model that strongly suggests that the smaller of the two energy gaps in MgB2, the so-called π gap, contains nodal lines with a six-fold symmetry (i-wave). The model also indicates that the larger gap, the so-called σ gap, is conventional s-wave. The model is an extension of the BCS gap equation that accounts for the elastic anisotropy in MgB2 and the Coulomb repulsion. It is based on a phononic pairing mechanism and assumes no coupling between the two energy gaps in MgB2 at zero temperature. All of the parameters of the model, such as sound velocities and masses, are independently determined material constants. The results agree with a previous ad-hoc hypothesis that the π energy gap has six nodal lines. That hypothesis was motivated by low-temperature measurements of the surface impedance and intermodulation distortion in high-quality thin films. We briefly review experimental evidence in the literature that is relevant to the energy-gap symmetry. We find that the evidence from the literature for s-wave is inconclusive. Our finding is that the π gap has six nodal lines.

Direct observation of multistep energy transfer in LHCII with fifth-order 3D electronic spectroscopy.

PubMed

Zhang, Zhengyang; Lambrev, Petar H; Wells, Kym L; Garab, Győző; Tan, Howe-Siang

2015-07-31

During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy is then funneled towards the reaction centre. These photosynthetic excitation energy transfer (EET) pathways are complex and proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) is an important tool to study EET processes in photosynthetic complexes. However, the multistep EET processes can only be indirectly inferred by correlating different cross peaks from a series of 2DES spectra. Here we directly observe multistep EET processes in LHCII using ultrafast fifth-order three-dimensional electronic spectroscopy (3DES). We measure cross peaks in 3DES spectra of LHCII that directly indicate energy transfer from excitons in the chlorophyll b (Chl b) manifold to the low-energy level chlorophyll a (Chl a) via mid-level Chl a energy states. This new spectroscopic technique allows scientists to move a step towards mapping the complete complex EET processes in photosynthetic systems.

Measurement of the ratios of branching fractions B(B0s --> Ds- pi+ pi+ pi-)/B(B0-->D- pi+ pi+ pi-) and B(B0s --> Ds- pi+)/B(B0-->D- pi+).

PubMed

Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; Dituro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

2007-02-09

Using 355 pb;{-1} of data collected by the CDF II detector in pp[over ] collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron, we study the fully reconstructed hadronic decays B_{(s)};{0}-->D_{(s)};{-}pi;{+} and B_{(s)};{0}-->D_{(s)};{-}pi;{+}pi;{+}pi;{-}. We present the first measurement of the ratio of branching fractions B(B_{s};{0}-->D_{s};{-}pi;{+}pi;{+}pi;{-})/B(B;{0}-->D;{-}pi;{+}pi;{+}pi;{-})=1.05+/-0.10(stat)+/-0.22(syst). We also update our measurement of B(B_{s};{0}-->D_{s};{-}pi;{+})/B(B;{0}-->D;{-}pi;{+}) to 1.13+/-0.08(stat)+/-0.23(syst), improving the statistical uncertainty by more than a factor of 2. We find B(B_{s};{0}-->D_{s};{-}pi;{+})=[3.8+/-0.3(stat)+/-1.3(syst)]x10;{-3} and B(B_{s};{0}-->D_{s};{-}pi;{+}pi;{+}pi;{-})=[8.4+/-0.8(stat)+/-3.2(syst)]x10;{-3}.

Quenching capabilities of long-chain carotenoids in light-harvesting-2 complexes from Rhodobacter sphaeroides with an engineered carotenoid synthesis pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dilbeck, Preston L.; Tang, Qun; Mothersole, David J.

Here, six light-harvesting-2 complexes (LH2) from genetically modified strains of the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. These strains were engineered to incorporate carotenoids for which the number of conjugated groups (N = N C=C + N C=O) varies from 9 to 15. The Rb. sphaeroides strains incorporate their native carotenoids spheroidene (N = 10) and spheroidenone (N = 11), as well as longer-chain analogues including spirilloxanthin (N = 13) and diketospirilloxantion (N = 15) normally found in Rhodospirillum rubrum. Measurements of the properties of the carotenoid firstmore » singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to those in LH2 complexes from various other bacterial species and thus are not significantly impacted by differences in polypeptide composition. Instead, variations in carotenoid-to-BChl a energy transfer are primarily regulated by the N-determined energy of the carotenoid S 1 excited state, which for long-chain (N ≥ 13) carotenoids is not involved in energy transfer. Furthermore, the role of the long-chain carotenoids switches from a lightharvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S 1 excited state B850*. This quenching is manifested as a substantial (~2-fold) reduction of the B850* lifetime and the B850* fluorescence quantum yield for LH2 housing the longest carotenoids« less

Quenching capabilities of long-chain carotenoids in light-harvesting-2 complexes from Rhodobacter sphaeroides with an engineered carotenoid synthesis pathway

DOE PAGES

Dilbeck, Preston L.; Tang, Qun; Mothersole, David J.; ...

2016-06-10

Here, six light-harvesting-2 complexes (LH2) from genetically modified strains of the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. These strains were engineered to incorporate carotenoids for which the number of conjugated groups (N = N C=C + N C=O) varies from 9 to 15. The Rb. sphaeroides strains incorporate their native carotenoids spheroidene (N = 10) and spheroidenone (N = 11), as well as longer-chain analogues including spirilloxanthin (N = 13) and diketospirilloxantion (N = 15) normally found in Rhodospirillum rubrum. Measurements of the properties of the carotenoid firstmore » singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to those in LH2 complexes from various other bacterial species and thus are not significantly impacted by differences in polypeptide composition. Instead, variations in carotenoid-to-BChl a energy transfer are primarily regulated by the N-determined energy of the carotenoid S 1 excited state, which for long-chain (N ≥ 13) carotenoids is not involved in energy transfer. Furthermore, the role of the long-chain carotenoids switches from a lightharvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S 1 excited state B850*. This quenching is manifested as a substantial (~2-fold) reduction of the B850* lifetime and the B850* fluorescence quantum yield for LH2 housing the longest carotenoids« less

Directing Energy Transfer in Panchromatic Platinum Complexes for Dual Vis-Near-IR or Dual Visible Emission from σ-Bonded BODIPY Dyes.

PubMed

Geist, Fabian; Jackel, Andrej; Irmler, Peter; Linseis, Michael; Malzkuhn, Sabine; Kuss-Petermann, Martin; Wenger, Oliver S; Winter, Rainer F

2017-01-17

We report on the platinum complexes trans-Pt(BODIPY)(8-ethynyl-BODIPY)(PEt 3 ) 2 (EtBPtB) and trans-Pt(BODIPY)(4-ethynyl-1,8-naphthalimide)(PR 3 ) 2 (R = Et, EtNIPtB-1; R = Ph, EtNIPtB-2), which all contain two different dye ligands that are connected to the platinum atom by a direct σ bond. The molecular structures of all complexes were established by X-ray crystallography and show that the different dye ligands are in either a coplanar or an orthogonal arrangement. π-stacking and several CH···F and short CH···π interactions involving protons at the phosphine substituents lead to interesting packing motifs in the crystal. The complexes feature several strong absorptions (ε = 3.2 × 10 5 -5.5 × 10 5 M -1 cm -1 ) that cover the regime from 350 to 480 nm (EtNIPtB-1 and EtNIPtB-2) or from 350 to 580 nm (EtBPtB). Besides the typical absorption bands of both kinds of attached dyes, they also feature an intense band near 400-420 nm, which is assigned by time-dependent density functional theory calculations to a higher-energy transition within the ethynyl-BODIPY (EtB) ligand or to charge transfer between the BODIPY (B) and naphthalimide (NI) chromophores. All complexes show dual fluorescence and phosphorescence emission from either the B (EtNIPtB-1 and EtNIPtB-2) or EtB (EtBPtB) ligand with a maximum phosphorescence quantum yield of 41% for EtNIPtB-1. The latter seems to be the highest reported value for room temperature phosphorescence from a BODIPY dye. The complete quenching of the emission from the chromophore absorbing at the higher energy and the appearance of the corresponding absorption bands in the fluorescence and phosphorescence excitation spectra indicate complete and rapid energy transfer to the chromophore with the lower-energy excited state, i.e., EtNI → B in EtNIPtB-1 and EtNIPtB-2 and B → EtB in EtBPtB. The latter process was further investigated by transient absorption spectroscopy, indicating that energy transfer is complete within 0.6 ns

45 CFR Appendix B to Part 96 - SSBG Reporting Form and Instructions

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false SSBG Reporting Form and Instructions B Appendix B... Pt. 96, App. B Appendix B to Part 96—SSBG Reporting Form and Instructions Instructions This form must... elsewhere in the annual report. b. “Transfers Out” should show funds transferred from the SSBG program to...

Turbulent energy transfer in electromagnetic turbulence: hints from a Reversed Field Pinch plasma

NASA Astrophysics Data System (ADS)

Vianello, N.; Bergsaker, H.

2005-10-01

The relationship between electromagnetic turbulence and sheared plasma flow in a Reversed Field Pinch is addressed. ExB sheared flows and turbulence at the edge tends to organize themeselves near marginal stability, suggesting an underlying energy exchange process between turbulence and mean flow. In MHD this process is well described through the quantity P which represents the energy transfer (per mass and time unit) from turbulence to mean fields. In the edge region of RFP configuration, where magnetic field is mainly poloidal and the mean ExB is consequently toroidal, the quantity P results: P =[ -ρμ0 + ]Vφr where Vφ is the mean ExB toroidal flow, ρ the mean mass density and b and v the fluctuations of velocity and magnetic field respectively. Both the radial profiles and the temporal evolution of P have been measured in the edge region of Extrap-T2R Reversed Field Pinch experiment. The results support the existence of oscillating energy exchange process between fluctuations and mean flow.

18 CFR 1b.12 - Transcripts.

Code of Federal Regulations, 2013 CFR

2013-04-01

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18 CFR 1b.19 - Submissions.

Code of Federal Regulations, 2014 CFR

2014-04-01

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18 CFR 1b.12 - Transcripts.

Code of Federal Regulations, 2014 CFR

2014-04-01

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18 CFR 1b.19 - Submissions.

Code of Federal Regulations, 2010 CFR

2010-04-01

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18 CFR 1b.12 - Transcripts.

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2010-04-01

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18 CFR 1b.12 - Transcripts.

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2012-04-01

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18 CFR 1b.19 - Submissions.

Code of Federal Regulations, 2013 CFR

2013-04-01

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18 CFR 1b.19 - Submissions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Submissions. 1b.19 Section 1b.19 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.19 Submissions. In the event the...

DFT STUDY OF HYDROGEN STORAGE ON Li- AND Na-DOPED C59B HETEROFULLERENE

NASA Astrophysics Data System (ADS)

Zahedi, Ehsan; Mozaffari, Majid

2014-05-01

Effect of light alkali metal (Li and Na) decorated on the C59B heterofullerene for hydrogen storage is considered using DFT-MPW1PW91 method. Results show that Li and Na atoms strongly prefer to adsorb on top of five-member and six-member ring where a carbon atom is replaced by a boron atom. Significant charge transfer from the alkali metal to the C59B compensates for the electron deficiency of C59B and makes the latter aromatic in nature. Corrected binding energies of hydrogen molecule on the alkali-doped C59B using counterpoise method, structural properties and NBO analysis indicate that first hydrogen molecule is adsorbed physically and does not support minimal conditions of DOE requirement. Finally, positive values of binding energies for the adsorption of a second hydrogen molecule show that alkali doped C59B are capable of storing a maximum of one hydrogen molecule.

Horizontal transfer of miR-106a/b from cisplatin resistant hepatocarcinoma cells can alter the sensitivity of cervical cancer cells to cisplatin.

PubMed

Raji, Grace R; Sruthi, T V; Edatt, Lincy; Haritha, K; Sharath Shankar, S; Sameer Kumar, V B

2017-10-01

Recent studies indicate that horizontal transfer of genetic material can act as a communication tool between heterogenous populations of tumour cells, thus altering the chemosensitivity of tumour cells. The present study was designed to check whether the horizontal transfer of miRNAs released by cisplatin resistant (Cp-r) Hepatocarcinoma cells can alter the sensitivity of cervical cancer cells. For this exosomes secreted by cisplatin resistant and cisplatin sensitive HepG2 cells (EXres and EXsen) were isolated and characterised. Cytotoxicity analysis showed that EXres can make Hela cells resistant to cisplatin. Analysis of miR-106a/b levels in EXres and EXsen showed that their levels vary. Mechanistic studies showed that miR-106a/b play an important role in EXsen and EXres mediated change in chemosensitivity of Hela cells to cisplatin. Further SIRT1 was identified as a major target of miR-106a/b using in silico tools and this was proved by experimentation. Also the effect of miR-106a/b in chemosensitivity was seen to be dependent on regulation of SIRT1 by miR-106a/b. In brief, this study brings into light, the SIRT1 dependent mechanism of miR-106a/b mediated regulation of chemosensitivity upon the horizontal transfer from one cell type to another. Copyright © 2017 Elsevier Inc. All rights reserved.

B97-3c: A revised low-cost variant of the B97-D density functional method

NASA Astrophysics Data System (ADS)

Brandenburg, Jan Gerit; Bannwarth, Christoph; Hansen, Andreas; Grimme, Stefan

2018-02-01

A revised version of the well-established B97-D density functional approximation with general applicability for chemical properties of large systems is proposed. Like B97-D, it is based on Becke's power-series ansatz from 1997 and is explicitly parametrized by including the standard D3 semi-classical dispersion correction. The orbitals are expanded in a modified valence triple-zeta Gaussian basis set, which is available for all elements up to Rn. Remaining basis set errors are mostly absorbed in the modified B97 parametrization, while an established atom-pairwise short-range potential is applied to correct for the systematically too long bonds of main group elements which are typical for most semi-local density functionals. The new composite scheme (termed B97-3c) completes the hierarchy of "low-cost" electronic structure methods, which are all mainly free of basis set superposition error and account for most interactions in a physically sound and asymptotically correct manner. B97-3c yields excellent molecular and condensed phase geometries, similar to most hybrid functionals evaluated in a larger basis set expansion. Results on the comprehensive GMTKN55 energy database demonstrate its good performance for main group thermochemistry, kinetics, and non-covalent interactions, when compared to functionals of the same class. This also transfers to metal-organic reactions, which is a major area of applicability for semi-local functionals. B97-3c can be routinely applied to hundreds of atoms on a single processor and we suggest it as a robust computational tool, in particular, for more strongly correlated systems where our previously published "3c" schemes might be problematic.

A Proposal of B to B Collaboration Process Model based on a Concept of Service and its Application to Energy Saving Service Business

NASA Astrophysics Data System (ADS)

Zhang, Qi; Kosaka, Michitaka; Shirahada, Kunio; Yabutani, Takashi

This paper proposes a new framework for B to B collaboration process based on a concept of service. Service value, which gives users satisfaction for provided services, depends on the situation, user characteristics, and user objectives in seeking the service. Vargo proposed Service Dominant Logic (SDL), which determines service value according to “value in use”. This concept illustrates the importance of the relationship between the service itself and its situation. This relationship is analogous to electro-magnetic field theory in physics. We developed the concept of service fields to create service value based on an analogy of the electro-magnetic field. By applying this concept to B to B collaboration, a model of service value co-creation in the collaboration can be formulated. Then, the collaboration can be described by 4 steps of KIKI model (Knowledge sharing related to service system, Identification of service field, Knowledge creation for new service idea, Implementation of service idea). As its application to B to B collaboration, the energy saving service business is reported to demonstrate the validity of the proposed collaboration model. This concept can be applied to make a collaboration process effective.

Momentum flux parasitic to free-energy transfer

DOE PAGES

Stoltzfus-Dueck, T.; Scott, B.

2017-05-11

An often-neglected portion of the radialmore » $$\\boldsymbol{E}\\times \\boldsymbol{B}$$ drift is shown to drive an outward flux of co-current momentum when free energy is transferred from the electrostatic potential to ion parallel flows. This symmetry breaking is fully nonlinear, not quasilinear, necessitated simply by free-energy balance in parameter regimes for which significant energy is dissipated via ion parallel flows. The resulting rotation peaking is counter-current and has a scaling and order of magnitude that are comparable with experimental observations. Finally, the residual stress becomes inactive when frequencies are much higher than the ion transit frequency, which may explain the observed relation of density peaking and counter-current rotation peaking in the core.« less

18 CFR 1b.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

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Code of Federal Regulations, 2010 CFR

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18 CFR 1b.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

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18 CFR 1b.1 - Definitions.

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18 CFR 1b.2 - Scope.

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2012-04-01

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18 CFR 1b.14 - Subpoenas.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Subpoenas. 1b.14 Section 1b.14 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.14 Subpoenas. (a) Service of a subpoena...

10 CFR Appendix Q to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Fluorescent Lamp Ballasts

Code of Federal Regulations, 2014 CFR

2014-01-01

... of Fluorescent Lamp Ballasts Q Appendix Q to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. Q Appendix Q to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Fluorescent...

10 CFR Appendix Q to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Fluorescent Lamp Ballasts

Code of Federal Regulations, 2012 CFR

2012-01-01

... of Fluorescent Lamp Ballasts Q Appendix Q to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. Q Appendix Q to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Fluorescent...

10 CFR Appendix Q to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Fluorescent Lamp Ballasts

Code of Federal Regulations, 2013 CFR

2013-01-01

... of Fluorescent Lamp Ballasts Q Appendix Q to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. Q Appendix Q to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Fluorescent...

Bodipy-C60 triple hydrogen bonding assemblies as heavy atom-free triplet photosensitizers: preparation and study of the singlet/triplet energy transfer.

PubMed

Guo, Song; Xu, Liang; Xu, Kejing; Zhao, Jianzhang; Küçüköz, Betül; Karatay, Ahmet; Yaglioglu, Halime Gul; Hayvali, Mustafa; Elmali, Ayhan

2015-07-01

Supramolecular triplet photosensitizers based on hydrogen bonding-mediated molecular assemblies were prepared. Three thymine-containing visible light-harvesting Bodipy derivatives ( B-1 , B-2 and B-3 , which show absorption at 505 nm, 630 nm and 593 nm, respectively) were used as H-bonding modules, and 1,6-diaminopyridine-appended C 60 was used as the complementary hydrogen bonding module ( C-1 ), in which the C 60 part acts as a spin converter for triplet formation. Visible light-harvesting antennae with methylated thymine were prepared as references ( B-1-Me , B-2-Me and B-3-Me ), which are unable to form strong H-bonds with C-1 . Triple H-bonds are formed between each Bodipy antenna ( B-1 , B-2 and B-3 ) and the C 60 module ( C-1 ). The photophysical properties of the H-bonding assemblies and the reference non-hydrogen bond-forming mixtures were studied using steady state UV/vis absorption spectroscopy, fluorescence emission spectroscopy, electrochemical characterization, and nanosecond transient absorption spectroscopy. Singlet energy transfer from the Bodipy antenna to the C 60 module was confirmed by fluorescence quenching studies. The intersystem crossing of the latter produced the triplet excited state. The nanosecond transient absorption spectroscopy showed that the triplet state is either localized on the C 60 module (for assembly B-1·C-1 ), or on the styryl-Bodipy antenna (for assemblies B-2·C-1 and B-3·C-1 ). Intra-assembly forward-backward (ping-pong) singlet/triplet energy transfer was proposed. In contrast to the H-bonding assemblies, slow triplet energy transfer was observed for the non-hydrogen bonding mixtures. As a proof of concept, these supramolecular assemblies were used as triplet photosensitizers for triplet-triplet annihilation upconversion.

Resonance energy transfer improves the biological function of bacteriorhodopsin within a hybrid material built from purple membranes and semiconductor quantum dots.

PubMed

Rakovich, Aliaksandra; Sukhanova, Alyona; Bouchonville, Nicolas; Lukashev, Evgeniy; Oleinikov, Vladimir; Artemyev, Mikhail; Lesnyak, Vladimir; Gaponik, Nikolai; Molinari, Michael; Troyon, Michel; Rakovich, Yury P; Donegan, John F; Nabiev, Igor

2010-07-14

Purple membrane (PM) from bacteria Halobacterium salinarum contains a photochromic protein bacteriorhodopsin (bR) arranged in a 2D hexagonal nanocrystalline lattice (Figure 1 ). Absorption of light by the protein-bound chromophore retinal results in pumping the protons through the PM creating an electrochemical gradient which is then used by the ATPases to energize the cellular processes. Energy conversion, photochromism, and photoelectrism are the inherent effects which are employed in many bR technical applications. bR, along with the other photosensitive proteins, is not able to deal with the excess energy of photons in UV and blue spectral region and utilizes less than 0.5% of the energy from the available incident solar light for its biological function. Here, we proceed with optimization of bR functions through the engineering of a "nanoconverter" of solar energy based on semiconductor quantum dots (QDs) tagged with the PM. These nanoconverters are able to harvest light from deep-UV to the visible region and to transfer this additionally collected energy to bR via Förster resonance energy transfer (FRET). We show that specific nanobio-optical and spatial coupling of QDs (donor) and bR retinal (acceptor) provide a means to achieve FRET with efficiency approaching 100%. We have finally demonstrated that the integration of QDs within PM significantly increases the efficiency of light-driven transmembrane proton pumping, which is the main bR biological function. This new QD-PM hybrid material will have numerous optoelectronic, photonic, and photovoltaic applications based on its energy conversion, photochromism, and photoelectrism properties.

High temperature Ir segregation in Ir-B ceramics: Effect of oxygen presence on stability of IrB 2 and other Ir-B phases

DOE PAGES

Xie, Zhilin; Terracciano, Anthony C.; Cullen, David A.; ...

2015-05-13

The formation of IrB 2, IrB 1.35, IrB 1.1 and IrB monoboride phases in the Ir–B ceramic nanopowder was confirmed during mechanochemical reaction between metallic Ir and elemental B powders. The Ir–B phases were analysed after 90 h of high energy ball milling and after annealing of the powder for 72 h at 1050°C in vacuo. The iridium monoboride (IrB) orthorhombic phase was synthesised experimentally for the first time and identified by powder X-ray diffraction. Additionally, the ReB 2 type IrB 2 hexagonal phase was also produced for the first time and identified by high resolution transmission electron microscope. Irmore » segregation along disordered domains of the boron lattice was found to occur during high temperature annealing. Furthermore, these nanodomains may have useful catalytic properties.« less

Comparison of the pharmacological profiles of murine antisense oligonucleotides targeting apolipoprotein B and microsomal triglyceride transfer protein

PubMed Central

Lee, Richard G.; Fu, Wuxia; Graham, Mark J.; Mullick, Adam E.; Sipe, Donna; Gattis, Danielle; Bell, Thomas A.; Booten, Sheri; Crooke, Rosanne M.

2013-01-01

Therapeutic agents that suppress apolipoprotein B (apoB) and microsomal triglyceride transfer protein (MTP) levels/activity are being developed in the clinic to benefit patients who are unable to reach target LDL-C levels with maximally tolerated lipid-lowering drugs. To compare and contrast the metabolic consequences of reducing these targets, murine-specific apoB or MTP antisense oligonucleotides (ASOs) were administered to chow-fed and high fat-fed C57BL/6 or to chow-fed and Western diet-fed LDLr−/− mice for periods ranging from 2 to 12 weeks, and detailed analyses of various factors affecting fatty acid metabolism were performed. Administration of these drugs significantly reduced target hepatic mRNA and protein, leading to similar reductions in hepatic VLDL/triglyceride secretion. MTP ASO treatment consistently led to increases in hepatic triglyceride accumulation and biomarkers of hepatotoxicity relative to apoB ASO due in part to enhanced expression of peroxisome proliferator activated receptor γ target genes and the inability to reduce hepatic fatty acid synthesis. Thus, although both drugs effectively lowered LDL-C levels in mice, the apoB ASO produced a more positive liver safety profile. PMID:23220583

A Full Overhead Cost Model for the U.S. Coast Guard Yard, Curtis Bay, Maryland.

DTIC Science & Technology

1982-06-01

80.0 STORAGE SHED B 43 A 35000.50 700.00 B 50 I IMPROVE SHINGLES 1750.43 40.70 B 75 I RELOCTE FLAMB STOR 22432.18 1246.23 81.0 FLAMABLE STORAGE B 43 A...35000.50 700.00 B 45 I UNKWN IMPRVMNT 50.48 1.04 B 50 I IMPROVE SHINGLES 1750.43 40.70 B 75 I RELOCTE FLAMB STOR 22432.18 1246.22 85.0 STORAGE SHED B

MobB protein stimulates nicking at the R1162 origin of transfer by increasing the proportion of complexed plasmid DNA.

PubMed Central

Perwez, T; Meyer, R

1996-01-01

An essential early step in conjugal mobilization of R1162, nicking of the DNA strand that is subsequently transferred, is carried out in the relaxosome, a complex of two plasmid-encoded proteins and DNA at the origin of transfer (oriT). A third protein, MobB, is also required for efficient mobilization. We show that in the cell this protein increases the proportion of molecules specifically nicked at oriT, resulting in lower yields of covalently closed molecules after alkaline extraction. These nicked molecules largely remain supercoiled, with unwinding presumably constrained by the relaxosome. MobB enhances the sensitivity of the oriT DNA to oxidation by permanganate, indicating that the protein acts by increasing the fraction of complexed molecules. Mutations that significantly reduce the amount of complexed DNA in the cell were isolated. However, plasmids with these mutations were mobilized at nearly the normal frequency, were nicked at a commensurate level, and still required MobB. Our results indicate that the frequency of transfer is determined both by the amount of time each molecule is in the nicked form and by the proportion of complexed molecules in the total population. PMID:8824623

Constraints on B and Higgs physics in minimal low energy supersymmetric models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carena, Marcela; /Fermilab; Menon, A.

2006-03-01

We study the implications of minimal flavor violating low energy supersymmetry scenarios for the search of new physics in the B and Higgs sectors at the Tevatron collider and the LHC. We show that the already stringent Tevatron bound on the decay rate B{sub s} {yields} {mu}{sup +}{mu}{sup -} sets strong constraints on the possibility of generating large corrections to the mass difference {Delta} M{sub s} of the B{sub s} eigenstates. We also show that the B{sub s} {yields} {mu}{sup +}{mu}{sup -} bound together with the constraint on the branching ratio of the rare decay b {yields} s{gamma} has strongmore » implications for the search of light, non-standard Higgs bosons at hadron colliders. In doing this, we demonstrate that the former expressions derived for the analysis of the double penguin contributions in the Kaon sector need to be corrected by additional terms for a realistic analysis of these effects. We also study a specific non-minimal flavor violating scenario, where there are flavor changing gluino-squark-quark interactions, governed by the CKM matrix elements, and show that the B and Higgs physics constraints are similar to the ones in the minimal flavor violating case. Finally we show that, in scenarios like electroweak baryogenesis which have light stops and charginos, there may be enhanced effects on the B and K mixing parameters, without any significant effect on the rate of B{sub s} {yields} {mu}{sup +}{mu}{sup -}.« less

Variations of B0 and B1 with the solar quiet Sq-current system and comparison with IRI-2012 model at Ilorin

NASA Astrophysics Data System (ADS)

Bello, S. A.; Abdullah, M.; Hamid, N. S. A.; Yoshikawa, A.; Olawepo, A. O.

2017-07-01

The ionospheric thickness (B0) and shape (B1) are bottomside profile parameters introduced by the International Reference Ionosphere (IRI) model. We have validated these parameters with the latest version of the IRI-2012 model and compared them with the solar quiet of geomagnetic H-component (SqH). The B0, B1 and SqH are calculated from the measurements obtained from digisonde DPS-4 sounder and the Magnetic Data Acquisition System (MAGDAS) magnetometer, respectively at Ilorin (geo latitude 8.50°N, geo longitude 4.68°E, and Magnetic dip 4.1°S) an equatorial station in the African sector. The study was for the year 2010, a year of low solar activity (with 27-day averaged solar index, F10.7 = 80 sfu). The results show that B0 for the entire months was higher during the daytime than during the night time. On the other hand, the magnitude of B1during the daytime period is lower than nighttime values and exhibit oscillatory pattern. By comparing the experimental observations of the profile parameters with the IRI-2012 model prediction, we found that B0 was fairly represented by the IRI model options during the nighttime period while discrepancies exist between the model estimates and the experimental values during the morning till midday. A close agreement exists between the observed B1 values and IRI model options. We observed a positive and significant correlation coefficient between B0 and SqH indicating a plausible relationship between these parameters while a weak and negative correlation coefficient between B1 and SqH was observed. We concluded that the difference in the relationship of SqH and the profile parameters B0 and B1 observed can be attributed to their sensitivity to the electric field which is responsible for the E × B drift which in turn modulate the height of the F2.

B cells from knock-in mice expressing broadly neutralizing HIV antibody b12 carry an innocuous B cell receptor responsive to HIV vaccine candidates.

PubMed

Ota, Takayuki; Doyle-Cooper, Colleen; Cooper, Anthony B; Doores, Katherine J; Aoki-Ota, Miyo; Le, Khoa; Schief, William R; Wyatt, Richard T; Burton, Dennis R; Nemazee, David

2013-09-15

Broadly neutralizing Abs against HIV protect from infection, but their routine elicitation by vaccination has not been achieved. To generate small animal models to test vaccine candidates, we have generated targeted transgenic ("knock-in") mice expressing, in the physiological Ig H and L chain loci, two well-studied broadly neutralizing Abs: 4E10, which interacts with the membrane proximal external region of gp41, and b12, which binds to the CD4 binding site on gp120. 4E10HL mice are described in the companion article (Doyle-Cooper et al., J. Immunol. 191: 3186-3191). In this article, we describe b12 mice. B cells in b12HL mice, in contrast to the case in 4E10 mice, were abundant and essentially monoclonal, retaining the b12 specificity. In cell culture, b12HL B cells responded avidly to HIV envelope gp140 trimers and to BCR ligands. Upon transfer to wild-type recipients, b12HL B cells responded robustly to vaccination with gp140 trimers. Vaccinated b12H mice, although generating abundant precursors and Abs with affinity for Env, were unable to rapidly generate neutralizing Abs, highlighting the importance of developing Ag forms that better focus responses to neutralizing epitopes. The b12HL and b12H mice should be useful in optimizing HIV vaccine candidates to elicit a neutralizing response while avoiding nonprotective specificities.