bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional annotation of proteins identified in human brain during the HUPO Brain Proteome Project pilot study
Authors: Mueller Michael , Martens Lennart , Reidegeld Kai A. , Hamacher Michael , Stephan Christian , Blüggel Martin , Körting Gerhard , Chamrad Daniel , Scheer Christian , Marcus Katrin , Meyer Helmut E. , Apweiler Rolf 
Published: August 2006

AbstractThe HUPO Brain Proteome Project is an initiative coordinating proteomics studies to characterise human and mouse brain proteomes. Proteins identified in human brain samples during the project's pilot phase were put into biological context through integration with various annotation sources followed by a bioinformatics analysis. The data set was related to the genome sequence via the genes encoding identified proteins including an assessment of splice variant identification as well as an analysis of tissue specificity of the respective transcripts. Proteins were furthermore categorised according to subcellular localisation, molecular function and biological process, grouped into protein families and mapped to biological pathways they are known to act in. Involvement in pathological conditions was examined based on association with entries in the online version of Mendelian Inheritance in Man and an interaction network was derived from curated protein‐proteininteraction data. Overall a non‐redundant set of 1804 proteins was identified in human brain samples. In the majority of cases splice variants could be unambiguously identified by unique peptides, including matches to several hypothetical transcripts of known as well as predicted genes.
Inductive effect of uncharged groups: dependence on electronegativity
Authors: Exner Otto , Böhm Stanislav 
Published: August 2006

AbstractSubstituent effects in rigid non‐conjugated systems were followed on the series of 3‐substituted 1‐fluoro‐bicyclo[1.1.1]pentanes and 2‐substituted 1‐fluoroethanes in the fixed ap conformation. Their energies were calculated within the framework of the density functional theory at the B3LYP/6‐311++G(3df,3pd)//B3LYP/6‐311++G(3df,3pd) level and the substituent effects were expressed in terms of isodesmic homodesmotic reactions. The results were confirmed by the energies of 1,4‐disubstituted bicyclo[2.2.2]octanes reported in the literature and calculated at a lower level. Interaction of two common substituents of low or medium polarity cannot be described as the classical inductive effect by one term, proportional in all series, but an additional parameter is necessary, which depends only on the first atom of the substituent and may be identified with its electronegativity. The second term decreases with the distance more steeply than the first term and is always much less important. Nevertheless its statistical significance was proved by several sensitive tests at the highest level used in statistics. When one of the substituents is charged (or at least strongly polar as NO2 or CN), the first term is much increased and the second becomes less significant or insignificant. Therefore, the standard definition of the inductive effect with a uniform, universally valid constant can be retained as far as one treats only the ionization equilibria, both in solution and in the gas phase, or kinetics with a strongly polar transition state.In contrast to the firm statistical proofs, the physical meaning of the electronegativity term was not established. Any relation to various group electronegativities does not exist, similarity to the 13C NMR shifts is merely qualitative. Copyright © 2006 John Wiley & Sons, Ltd.
Photochromism of dihydroindolizines Part VI: synthesis and photochromic behavior of a novel type of IR‐absorbing photochromic compounds based on highly conjugated dihydroindolizines
Authors: Ahmed Saleh Abdel 
Published: August 2006

AbstractNovel photochromic bis‐styryl dihydroindolizines (DHIs) 5a‐β bearing different cycloalkanone ring sizes were prepared in 11–42% yield via nucleophilic addition of bis‐styryl cycloalkanones 2a–k to substituted spirocyclopropenes 1a–g. The absorption maxima (λmax) of the colored betaines 4a‐β (formed after UV‐irradiation) were detected by millisecond flash photolysis, laser flash photolysis as well as FT‐UV/VIS measurements. All betaines 4a‐β showed two absorption maxima, one in the visible region (500–575 nm) and another one in the IR‐region (800–878 nm). The kinetics of the fast cyclizing process of betaines 4a‐β to DHIs 5a‐β were studied in dichloromethane solution by millisecond flash photolysis and were found to take place in the millisecond range (76–450 msec). The strong colorability of betaines 4a‐β may be attributed to the highly conjugated betaine structures as well as to the presence of the carbonyl chromophore. Interestingly, a remarkable photo‐fatigue resistance of some studied betaines 4 showed t30‐values higher than the standard one. Large solvatochromic effects on the absorption maxima (λmax) as well as a substantial increase of the half‐lives (t1/2) with solvent polarity of betaines 3a‐β were also observed. Copyright © 2006 John Wiley & Sons, Ltd.
An integrated approach to the study of intramolecular hydrogen bonds in malonaldehyde enol derivatives and naphthazarin: trend in energetic versus geometrical consequences
Authors: Musin Ryza N. , Mariam Yitbarek H. 
Published: August 2006

AbstractDensity functional and atoms‐in‐molecules (AIM) and natural bond orbital (NBO) approaches have been applied in the study of energetic (E), geometrical (G) and electronic (AIM and NBO) consequences of H bonding in malonaldehyde (MAE) derivatives and naphthazarin (NZ). AIM parameters and other measures of HB strength were used: (a) for the verification of (i) the reliability of the O···O distance (G consequence) as an indicator of IMHB strength; (ii) the capacity of the classically computed energetic parameters (ΔESEs) to serve as acceptable measures of IMHB strength; and (b) for the separation of the ΔESEs into (i) stabilization (HB) energies (EHSEs) that serve as apparent IMHB energies (EHB,As), and (ii) stabilization (isomerization) energies (ENSEs) that do not (owing to intractable contributions that are not germane to the solitary HB donor(D)‐acceptor(A) interactions). Some of the sources of the anomalies have been rationalized. AIM topological properties were used to study the nature of the IMHB interactions. An exponential parametric model for the correlation of EHSE with the O···O distance, which has asymptotic characteristics at long O···O distances, was obtained. The model (a) has predictive ability, that is, can be used to estimate, in an empirical manner, EHB,As that are otherwise grossly underestimated, and (b) can treat both the MAE derivatives and the NZ systems even though they possess very different resonant spacers connecting the HB D‐A segments. MAE and NZ are also demonstrated to have essentially the same IMHB strength. By contrast, a quadratic model for EHSE‐HB distance correlation was found to be unphysical. Use of electronic consequences of H bonding was shown to be essential for study of IMHBs with intractable interactions. Thus, AIM energy density and NBO second‐order interaction energy parameters were used for the verification of predictions of IMHB strengths made on the bases of energetic and geometrical consequences. Copyright © 2006 John Wiley & Sons, Ltd.
A prospective study of the impact of genetic susceptibility testing for BRCA1/2 or HNPCC on family relationships
Authors: Oostrom Iris van , Meijers‐Heijboer Hanne , Duivenvoorden Hugo J. , Bröcker‐Vriends Annette H. J. T. , van Asperen Christi J. , Sijmons Rolf H. , Seynaeve Caroline , Van Gool Arthur R. , Klijn Jan G. M. , Riedijk Samantha R. , van Dooren Silvia , Tibben Aad 
Published: August 2006

AbstractThis study assessed the impact of genetic testing for cancer susceptibility on family relationships and determinants of adverse consequences for family relationships. Applicants for genetic testing of a known familial pathogenic mutation in BRCA1/2 or a HNPCC related gene (N=271) rated the prevalence and nature of changes in family relationships, familial difficulties and conflicts due to genetic testing 6 months after receiving the test result. The level of family functioning, differentiation from parents, support and familial communication style regarding hereditary cancer were assessed before receiving the test result. Genetic testing affected some family relationships in a positive way (37%), i.e. by feeling closer, improved communication and support, more appreciation of the relative and relief of negative test result. A minority reported unwanted changes in relationships (19%), problematic situations (13%) or conflicts (4%). Adverse effects comprised feelings of guilt towards children and carrier siblings, imposed secrecy and communication problems. Predictors of adverse consequences on family relationships were reluctance to communicate about hereditary cancer with relatives and disengaged‐rigid or enmeshed‐chaotic family functioning. Open communication between relatives should be stimulated because a lack of open communication may be an important determinant of familial adverse effects. Copyright © 2006 John Wiley & Sons, Ltd.
A family‐based model to predict fear of recurrence for cancer survivors and their caregivers
Authors: Mellon Suzanne , Kershaw Trace S. , Northouse Laurel L. , Freeman‐Gibb Laurie 
Published: August 2006

AbstractAlthough fear of cancer recurrence is a great concern among survivors and their families, few studies have examined predictors of fear of recurrence. The purpose of this study was to identify factors associated with fear of recurrence in a population‐based sample (N = 246) and determine if survivors and family caregivers influenced one another's fear of recurrence. A family framework guided the study and analyses included multilevel modeling using the Actor‐Partner Interdependence Model. Results indicated that survivors and family caregivers influenced each other's fear of recurrence and that caregivers had significantly more fear of recurrence than survivors. More family stressors, less positive meaning of the illness, and age were related to elevated fear of cancer recurrence for both survivors and caregivers. Copyright © 2006 John Wiley & Sons, Ltd.
Conformational flexibility of RecA protein filament: Transitions between compressed and stretched states
Authors: Petukhov Michael , Lebedev Dmitry , Shalguev Valery , Islamov Akhmed , Kuklin Aleksandr , Lanzov Vladislav , Isaev‐Ivanov Vladimir 
Published: August 2006

AbstractRecA protein is a central enzyme in homologous DNA recombination, repair and other forms of DNA metabolism in bacteria. It functions as a flexible helix‐shaped filament bound on stretched single‐stranded or double‐stranded DNA in the presence of ATP. In this work, we present an atomic level model for conformational transitions of the RecA filament. The model describes small movements of the RecA N‐terminal domain due to coordinated rotation of main chain dihedral angles of two amino acid residues (Psi/Lys23 and Phi/Gly24), while maintaining unchanged the RecA intersubunit interface. The model is able to reproduce a wide range of observed helix pitches in transitions between compressed and stretched conformations of the RecA filament. Predictions of the model are in agreement with Small Angle Neutron Scattering (SANS) measurements of the filament helix pitch in RecA::ADP‐AlF4 complex at various salt concentrations. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Spin dynamics and hyperfine interaction in InAs semiconductor quantum dots
Authors: Eble B. , Braun P.‐F. , Krebs O. , Lombez L. , Marie X. , Urbaszek B. , Amand T. , Lagarde D. , Renucci P. , Voisin P. , Lemaître A. , Kowalik K. , Kudelski A. , Kalevich V.K. , Kavokin K. V. 
Published: August 2006

AbstractWe present a detailed study of the hyperfine interaction between carrier and nuclear spins in InAs semiconductor quantum dots. Time resolved measurements on excitons in positively charged quantum dots show the electron spin relaxation due to random fluctuations of the spin orientation of the nuclei in the quantum dot. A complimentary aspect of the hyperfine interaction can be uncovered in single dot continuous wave photoluminescence experiments in a weak magnetic field, namely the Overhauser shift due to the dynamic polarisation of the nuclei following excitation with circularly polarised light. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton‐spin relaxation in weakly confining quantum dots due to spin–orbit interaction
Authors: Tsitsishvili E. , Kalt H. , v. Baltz R. 
Published: August 2006

AbstractIn weakly confining quantum structures such as interfacial islands or quantum disks the exciton‐spin relaxation is governed by two independent electron and hole spin flip processes between the optically active and dark states. A microscopic theory for these transitions is presented which is based on second order spin–orbit and carrier–phonon interaction processes. We found that the sequential relaxation between bright and dark states leads to much faster exciton‐spin relaxation than for strongly confining (“small”) quantum dots where the dominant process stems from electron–hole exchange interaction plus hole deformation potential coupling. In addition, the fast exciton spin relaxation implies that the (exciton‐bound) electron spin flip time is also much shorter than for a single electron. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strong and weak coupling of single quantum dot excitons in pillar microcavities
Authors: Reitzenstein S. , Hofmann C. , Löffler A. , Kubanek A. , Reithmaier J.‐P. , Kamp M. , Kulakovskii V. D. , Keldysh L. V. , Reinecke T. L. , Forchel A. 
Published: August 2006

AbstractWe report on strong as well as weak coupling of self assembled In0.30Ga0.70As quantum dots (QDs) in high‐Q semiconductor micropillar cavities grown by molecular beam epitaxy. Using electron beam lithography and deep plasma etching, micropillars with high Q‐factors (about 10000 for 1.6 µm diameter) were realized. The low QD density in the present structures allows us to investigate the interaction of single QD excitons and the vacuum field of the microcavity by temperature tuning of exciton lines into resonance with the cavity mode. We will present an example where QD excitons with different emission energies show strong or weak coupling with the optical mode of the same micropillar at different resonance temperatures. Here, the individual coupling behaviour is described in terms of a different spatial position of the QDs relative to the field maximum of the cavity mode. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin Coulomb drag: an intrinsic dissipation mechanism in spintronics
Authors: D'Amico I. , Ullrich C. A. 
Published: August 2006

AbstractSpin Coulomb drag (SCD) plays an important role in spintronics as an intrinsic source of dissipation for spin currents in metals and semiconductors. We discuss two aspects of SCD and their practical relevance: the power loss in a generic spintronics device, and the damping of collective spin‐density excitations in semiconductor quantum wells. A purely optical quantitative measurement of the SCD effect is suggested. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ramsey fringes in a single InGaAs/GaAs quantum dot
Authors: Ester P. , Stufler S. , de Michaelis Vasconcellos S. , Bichler M. , Zrenner A. 
Published: August 2006

AbstractWe report the observation of Ramsey fringes in single InGaAs/GaAs quantum dots. With double pulse p/2 excitation it is possible to control the occupancy and the phase of a quantum dot. The occupancy of the quantum dot oscillates with detuning. These Ramsey fringes are caused by a voltage dependent detuning of the QD. Due to the double pulse excitation the spectral sensitivity is strongly enhanced as compared to single pulse experiments. At long delay times we are able to resolve extremely narrow spectral fringes, clearly below the homogeneous linewidth of the underlying QD two level system. Our results demonstrate precision measurements on single quantum dots with strong implications for future quantum gates and quantum measurements. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear optical response and exciton dephasing in quantum dots
Authors: Muljarov E. A. , Zimmermann R. 
Published: August 2006

AbstractThe full time‐dependent four‐wave mixing polarization in quantum dots is microscopically calculated, taking into account acoustic phonon‐assisted transitions between different exciton states of the dot. It is shown that quite different dephasing times of higher exciton states in pancake anisotropic InGaAs quantum dots are responsible for the experimentally observed [1] double‐exponential decay in the photon echo signal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of quantum dot luminescence from acoustically excited intersubband transitions
Authors: Milde F. , Ahn K. J. , Knorr A. 
Published: August 2006

AbstractIn this paper a theory of acoustically driven intersubband transitions in semiconductor quantum dots is developed. Well off‐resonant acoustic excitation leads to subsequently emitted THz radiation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamical T‐matrix theory for high‐density excitons in coupled quantum wells
Authors: Zimmermann R. 
Published: August 2006

AbstractExcitons in coupled quantum wells open the possibility to reach high densities close to equilibrium. In a recent experiment employing a lateral trap potential, a blue shift and a broadening of the exciton emission line has been seen [D. W. Snoke et al., Solid State Commun. 134, 37 (2005)]. The standard Hartree–Fock treatment can explain the blue shift but fails to give a finite broadening. Starting from the (spin‐dependent) many‐exciton Hamiltonian with direct and exchange potential, we present a dynamical T‐matrix calculation for the single‐exciton Green's function which is directly related to the frequency‐ and angle‐resolved photoluminescence. The calculated spectrum is blue shifted and broadened due to exciton–exciton scattering. At high excitation, both the spectrum and the angular emission are getting narrow. This is a direct manifestation for off‐diagonal long range order and a precursor of condensation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective excitation kinetics in the condensation of polaritons
Authors: Sarchi Davide , Savona Vincenzo 
Published: August 2006

AbstractWe develop a kinetic model for polariton condensation, in which the field dynamics of collective excitations is treated self‐consistently during the condensation kinetics. This model allows to account properly for the quantum fluctuations of the condensate. Using realistic parameters, we prove that long‐wavelength excitations considerably deplete the condensate just above threshold. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preventive effects of Azadirachta indica on benzo(a)pyrene‐DNA adduct formation in murine forestomach and hepatic tissues
Authors: Gangar Subhash Chander , Sandhir Rajat , Rai Durg Vijay , Koul Ashwani 
Published: August 2006

AbstractIn the present investigation, the effects of aqueous Azadirachta indica leaf extract (AAILE) on 3H‐benzo(a)pyrene‐DNA [3H‐B(a)P‐DNA] adduct formation, the status of biotransformation enzymes and reduced glutathione (GSH) content were evaluated in the forestomach and liver of Balb/c mice. Two weeks of AAILE treatment reduced the 3H‐B(a)P‐DNA adduct levels by 31.6% in forestomach tissue. Similarly, 3H‐B(a)P‐DNA adduct levels were decreased by 34.7% in the liver of AAILE treated mice compared with their control counterparts. After AAILE treatment, the cytochrome P450 content decreased, whereas the GSH content increased significantly in the hepatic tissue. In the forestomach as well as in the liver, the cytochrome b5 content declined, whereas an increase in glutathione‐S‐transferase (GST) activity was observed in both tissues. These observations suggested that AAILE may have reduced the metabolic activation of 3H‐B(a)P with enhanced detoxification of its active metabolites, hence the observed decrease in the levels of 3H‐B(a)P‐DNA adducts. These molecular and biochemical modulations observed at the initiation phase of carcinogenesis seems to be significant and could be correlated with the chemopreventive effects of A. indica against B(a)P induced forestomach tumorigenesis. Copyright © 2006 John Wiley & Sons, Ltd.
Antiplasmodial activity of Homalium letestui
Authors: Okokon Jude E. , Ita Basil , Udokpoh Aniekan E. 
Published: August 2006

AbstractThe in vivo antiplasmodial activity of the ethanol root extract of Homalium letestui used as a malaria remedy in Southern Nigeria was evaluated in Plasmodium berghei berghei infected mice. Homalium letestui root extract (500–1000 mg/kg/day) exhibited significant (p < 0.05) blood schizontocidal activities both in a 4‐day early infection test and in an established infection with a considerable mean survival time comparable to that of the standard drug, chloroquine, 5 mg/kg/day. The root extract possesses significant (p < 0.05) antiplasmodial activity, which can be exploited in malaria therapy. Copyright © 2006 John Wiley & Sons, Ltd.
Correlation between the In Vitro antioxidant activity and polyphenol content of aqueous extracts from bulgarian herbs
Authors: Kiselova Yoana , Ivanova Diana , Chervenkov Trifon , Gerova Daniela , Galunska Bistra , Yankova Tatyana 
Published: August 2006

AbstractThe water phase antioxidant activity of extracts from 23 Bulgarian medicinal plants was studied in relation to their polyphenol content in comparison with mate, black tea, honeybush and rooibos foreign species. Antioxidant activity was measured by the ABTS (2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) cation radical decolorization assay, and the total polyphenol content was assayed according to the Folin‐Ciocalteu method. Five Bulgarian plant extracts exhibited higher antioxidant activity than that of mate, which is 21.7% of all Bulgarian herbs included in this study. These were Alchemilla vulgaris L. (4.79 ± 0.14 mm), Sambucus ebulus L. (4.03 ± 0.07 mm), Mentha spicata L. (3.90 ± 0.03 mm), Fragaria vesca L. (3.74 ± 0.06 mm), Crataegus monogyna Jacq. (3.63 ± 0.05 mm). Another eight Bulgarian medicinal plant extracts exhibited an intermediate antioxidant activity – lower than that of mate and higher than that of honeybush, which makes 34.8% of all Bulgarian herbs included in the study. More than half of the herbal extracts included in the present study exhibited antioxidant activity higher than or comparable to the reference foreign plants. A positive correlation (r = 0.92) between antioxidant activity and polyphenol content was found, suggesting that the antioxidant capacity of the aqueous plant extracts is due to a great extent to their polyphenols. Copyright © 2006 John Wiley & Sons, Ltd.