bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific Inhibitors of the Breast Cancer Resistance Protein (BCRP)
Authors: Pick Anne , Klinkhammer Werner , Wiese Michael 
Published: July 2010

AbstractA new class of specific breast cancer resistance protein (BCRP) inhibitors was identified, showing no inhibition of the ATP binding cassette (ABC) transporters P‐gp and MRP1. Some of these modulators inhibit BCRP with high potency; they are only slightly less potent than Ko143 and could serve as promising lead structures for the design of novel effective BCRP inhibitors. These inhibitors are structurally related to tariquidar (XR9576) and belong to a library of multidrug‐resistance modulators synthesized by our research group. The absence of the tetrahydroisoquinoline substructure appears to play a crucial role for specificity; we found that the presence of this substructure is not essential for interaction with BCRP. To determine the type of interaction between pheophorbide A and compounds with and without the tetrahydroisoquinoline substructure, various substrate pheophorbide A concentrations were used in enzyme kinetics assays. The resulting data show that these compounds share a noncompetitive‐type interaction with pheophorbide A. Experiments with imatinib and pheophorbide A revealed a mixed‐type interaction. The combination of imatinib and compounds with and without the tetrahydroisoquinoline substructure resulted in a positive cooperative effect, indicating that imatinib engages a binding site distinct from that of the new compounds on one side and distinct from that of pheophorbide A on the other side as well. The results of this study suggest that the category of BCRP‐specific inhibitors, which includes only fumitremorgin C, Ko143 and analogues, and novobiocin needs to be extended by this new class of inhibitors, which possess three key characteristics: specificity, potency, and low toxicity.
Quantum‐Dot‐Sensitized Solar Cells
Authors: Rühle Sven , Shalom Menny , Zaban Arie 
Published: July 2010

AbstractQuantum‐dot‐sensitized solar cells (QDSCs) are a promising low‐cost alternative to existing photovoltaic technologies such as crystalline silicon and thin inorganic films. The absorption spectrum of quantum dots (QDs) can be tailored by controlling their size, and QDs can be produced by low‐cost methods. Nanostructures such as mesoporous films, nanorods, nanowires, nanotubes and nanosheets with high microscopic surface area, redox electrolytes and solid‐state hole conductors are borrowed from standard dye‐sensitized solar cells (DSCs) to fabricate electron conductor/QD monolayer/hole conductor junctions with high optical absorbance. Herein we focus on recent developments in the field of mono‐ and polydisperse QDSCs. Stability issues are adressed, coating methods are presented, performance is reviewed and special emphasis is given to the importance of energy‐level alignment to increase the light to electric power conversion efficiency.
Metal‐Enhanced Fluorescence of CdTe Nanocrystals in Aqueous Solution
Authors: Li Rongqing , Xu Shuhong , Wang Chunlei , Shao Haibao , Xu Qinying , Cui Yiping 
Published: July 2010

AbstractMetal‐enhanced fluorescence of semiconductor nanocrystals (NCs) is investigated. There is very little attention paid to the metal‐enhanced fluorescence in aqueous solution, which has great potential applications in bioscience. In this work, we directly observe metal‐enhanced fluorescence of CdTe NC solution by simply mixing CdTe NCs and Au nanoparticles, both of which are negatively charged. In order to study this kind of photoluminescence enhancement in aqueous solutions, we propose a calibration method, which takes into account the light attenuation in solutions. After consideration of the light weakening in transmission, the maximal PL enhancement is about 3 times as large as the ones without Au NPs. Some factors related to the enhanced magnitude of fluorescence, for instance, the concentration and the molar feed ratio of CdTe NCs and Au NPs, are studied in detail. Furthermore, the decreased lifetimes of CdTe NCs induced by Au NPs are also obtained, which are in accord with the enhancement of the photoluminescence.
Asymmetry and Non‐Adiabaticity in Fragmentation of Disulfide Bonds upon Electron Capture
Authors: Gámez José A. , Serrano‐Andrés Luis , Yáñez Manuel 
Published: July 2010

AbstractAlthough it has been generally assumed that electron attachment to disulfide derivatives leads to a systematic and significant activation of the SS bond, we show, by using [CH3SSX] (X=CH3, NH2, OH, F) derivatives as model compounds, that this is the case only when the X substituents have low electronegativity. Through the use of MP2, QCI and CASPT2 molecular orbital (MO) methods, we elucidate, for the first time, the mechanisms that lead to unimolecular fragmentation of disulfide derivatives after electron attachment. Our theoretical scrutiny indicates that these mechanisms are more intricate than assumed in previous studies. The most stable products, from a thermodynamic viewpoint, correspond to the release of neutral molecules; CH4, NH3, H2O, and HF. However, the barriers to reach these products depend strongly on the electronegativity of the X substituents. Only for very electronegative substituents, such as OH or F, the loss of H2O or HF is the most favorable process, and likely the only one observed. This is possible because of two concomitant factors, 1) the extra electron for [CH3SSX]− (X=OH, F) occupies a σ*(SX) MO, which favors the cleavage of the SX bond, and 2) the activation barriers associated with the hydrogen transfer process to produce H2O and HF are rather low. Only when the substituents are less electronegative (X=H, CH3, NH2) the extra electron is located in a σ*(SS) orbital and the cleavage of the disulfide bridge becomes the most favorable process. The intimate mechanism associated with the SS bond dissociation process also depends strongly on the nature of the substituent. For X=H or CH3 the process is strictly adiabatic, while for X=NH2 it proceeds through a conical intersection (CI) associated with the charge reorganization necessary to obtain, from a molecular anion with the extra electron delocalized in a σ*(SS) antibonding orbital, two fragments with the proper charge localization.
Post‐stroke depression: the case for augmented, individually tailored cognitive behavioural therapy
Authors: Broomfield Niall M. , Laidlaw Ken , Hickabottom Emma , Murray Marion F. , Pendrey Rachel , Whittick Janice E. , Gillespie David C. 
Published: July 2010

AbstractIn this review, we begin by considering why post‐stroke depression (PSD) is so prevalent. We then examine the current evidence base to support cognitive behavioural therapy (CBT) as a treatment approach for the condition. While there is limited evidence currently, we demonstrate that much remains to be established with regard to PSD and the efficacy of CBT. We argue there is every reason to believe CBT should be an effective treatment, but that clinicians must augment and individually tailor this approach to ensure effectiveness. We set out our rationale for a novel augmented, individually tailored CBT protocol, and describe five key components that we believe once incorporated, and tested using randomized controlled methods, should enhance treatment outcome of PSD. Copyright © 2010 John Wiley & Sons, Ltd.Key Practitioner Message:• Depression is a common consequence of stroke.• Despite a lack of clear evidence, there is reason to believe cognitive behavioural therapy (CBT) for post‐stroke depression should be effective, if it is adapted and tailored to the specific needs of stroke survivors.• Augmented and individually tailored therapy using motivational interviewing techniques, grief resolution, selection optimization compensation, cognitive deficits adaptations and executive skills training is recommended.• It is important to individualize augmented CBT, based on principles of case formulation.
Growth and characterization of calcium hydrogen phosphate dihydrate crystals from single diffusion gel technique
Authors: Rajendran K. , Dale Keefe C. 
Published: July 2010

AbstractCalcium hydrogen phosphate dihydrate (CaHPO4·2H2O, CHPD) a dissolved mineral in urine is known to cause renal or bladder stones in both human and animals. Growth of CHPD or brushite using sodium metasilicate gel techniques followed by light and polarizing microscopic studies revealed its structural and morphological details. Crystal identity by powder x‐ray diffraction confirmed the FT‐IR and FT‐Raman spectroscopic techniques as alternate methods for fast analysis of brushite crystals which could form as one type of renal stones. P‐O‐P asymmetric stretchings in both FT‐IR (987.2, 874.1 and 792 cm‐1) and FT‐Raman (986.3 cm‐1, 1057.6 cm‐1 and 875.2 cm‐1) were found as characteristics of brushite crystals. Differential Scanning Calorimetry (DSC) analysis revealed brushite crystallization purity using gel method by studying their endothermic peaks. This study incorporated a multidisciplinary approach in characterizing CHPD crystals grown in vitro to help formulate prevention or dissolution strategy in controlling urinary stone growth. Initial studies with 0.2 M citric acid ions as controlling agent in the nucleation of brushite crystals further support the presented approach. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Ba ions substitution on multiferroic properties of BiFeO3 perovskite
Authors: Gautam A. , Rangra V. S. 
Published: July 2010

AbstractDielectric, magnetic and ferroelectric properties of Bi1‐xBaxFeO3(x = 0.1, 0.2 and 0.3) synthesized by solid state reaction method are reported. X‐ray diffraction pattern showed that Bi1‐xBaxFeO3was single phase. Ba substitution has led to a decrease in grain size and hence an increase in the electrical resistivity. The variation of dielectric constant and loss has been studied over a frequency range of 1 kHz – 2 MHz at room temperature. Ba doping leads to effective suppression of the spiral spin structure of BiFeO3, resulting in the appearance of net magnetization. Improved multiferroic properties of Bi0.8Ba0.2FeO3 ceramic with remnant magnetization and polarization 0.093 emu/g and 0.808 µC/cm2, respectively, were obtained. The evidence of ferromagnetism and ferroelectric hysteresis loops in Bi1‐xBaxFeO3system at room temperature makes it a good candidate for potential applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient multi‐threshold voltage techniques for minimum leakage current in nanoscale technology
Authors: Rjoub Abdoul , Al‐Ajlouni Motasem 
Published: July 2010

AbstractThe influence of multi‐threshold voltage technique on reducing the leakage power in CMOS circuits at transistor level based on Nanoscale SPICE parameters is investigated in this paper. Based on Artificial Intelligence search algorithms, three new algorithms are proposed to determine the exact threshold voltage for each transistor in order to minimize the leakage current at lowest value. These algorithms are: Slack Time Search Algorithm (STS), Leakage Power Search Algorithm (LPS), Leakage and Slack Time Search Algorithm (LSS). As a result, 70% of sub‐threshold leakage current is reduced without degrading the performance. Based on 22 nm predictive SPICE parameters proposed by BSIM4, simulation results verified the validity of the proposed algorithms. Copyright © 2010 John Wiley & Sons, Ltd.
Generation of current mode filters using NAM expansion
Authors: Soliman Ahmed M. 
Published: July 2010

AbstractSystematic synthesis method to generate a family of current mode band‐pass–low‐pass circuits based on nodal admittance matrix (NAM) expansion is given. Eight equivalent circuits are obtained, five of them are new. Each of the generated circuits uses two grounded capacitors and three grounded resistors and two balanced output current conveyor (BOCCII) or two balanced output inverting current conveyor (BOICCII) or a combination of the two types. Generation of a low input impedance current mode band‐pass–low‐pass circuits based on NAM expansion results in 16 equivalent circuits. The NAM expansion is also used to generate 32 equivalent current mode universal filters using four BOCCII or BOICCII or a combination of the two types. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐switch flyback PWM DC‐DC converter in continuous‐conduction mode
Authors: Murthy‐Bellur Dakshina , Kazimierczuk Marian K. 
Published: July 2010

AbstractThe two‐switch flyback DC‐DC converter is an extended version of the conventional single‐switch flyback converter. An additional switch and two clamping diodes serve as a simple, but an effective way to limit the switch overvoltages, which occur in the conventional single‐switch flyback converter due to the ringing of the resonant circuit formed by the transformer leakage inductance and the transistor output capacitance. The clamping diodes in the two‐switch flyback topology clamp the maximum voltage across each switch equal to the DC input voltage. This paper presents a detailed steady‐state analysis and design procedure of the diode‐clamped two‐switch flyback converter operated in continuous‐conduction mode (CCM). The power loss in each component of the two‐switch flyback converter is compared with those of the single‐switch flyback converters with and without RCD clamp, and is presented in a tabular form. The two‐switch flyback converter was bread‐boarded to validate the theoretical analysis. Experimental results from a 10 V/30 W, 100 kHz laboratory prototype verified that the maximum switch voltage is limited to the DC input voltage. Copyright © 2010 John Wiley & Sons, Ltd.
Cell type–specific expression of adenomatous polyposis coli in lung development, injury, and repair
Authors: Li Aimin , Xing Yiming , Chan Belinda , Heisterkamp Nora , Groffen John , Borok Zea , Minoo Parviz , Li Changgong 
Published: July 2010

AbstractAdenomatous polyposis coli (Apc) is critical for Wnt signaling and cell migration. The current study examined Apc expression during lung development, injury, and repair. Apc was first detectable in smooth muscle layers in early lung morphogenesis, and was highly expressed in ciliated and neuroendocrine cells in the advanced stages. No Apc immunoreactivity was detected in Clara or basal cells, which function as stem/progenitor cell in adult lung. In ciliated cells, Apc is associated mainly with apical cytoplasmic domain. In response to naphthalene‐induced injury, Apcpositive cells underwent squamous metaplasia, accompanied by changes in Apc subcellular distribution. In conclusion, both spatial and temporal expression of Apc is dynamically regulated during lung development and injury repair. Differential expression of Apc in progenitor vs. nonprogenitor cells suggests a functional role in cell‐type specification. Subcellular localization changes of Apc in response to naphthalene injury suggest a role in cell shape and cell migration. Developmental Dynamics 239:2288–2297, 2010. © 2010 Wiley‐Liss, Inc.
Expression of the Zebrafish CD133/prominin1 Genes in Cellular Proliferation Zones in the Embryonic Central Nervous System and Sensory Organs
Authors: McGrail Maura , Batz Lindsey , Noack Kristin , Pandey Saumya , Huang Yong , Gu Xun , Essner Jeffrey J. 
Published: July 2010

AbstractExpression pattern of the zebrafish CD133/prominin1a gene in the 36 hour post fertilization embryo. prominin1a is expressed in the lens in the eye and in the ventricular zone on the ventral side of the midbrain tegmentum. From McGrail et al., Developmental Dynamics 239:1849–1857, 2010
Fixing an irrelevant TCRα chain reveals the importance of TCRβ diversity for optimal TCRαβ pairing and function of virus‐specific CD8+ T cells
Authors: Valkenburg Sophie A. , Day E. Bridie , Swan Natasha G. , Croom Hayley A. , Carbone Francis R. , Doherty Peter C. , Turner Stephen J. , Kedzierska Katherine 
Published: July 2010

AbstractTCR repertoire diversity can influence the efficacy of CD8+ T‐cell populations, with greater breadth eliciting better protection. We analyzed TCRβ diversity and functional capacity for influenza‐specific CD8+ T cells expressing a single TCRα chain. Mice (A7) transgenic for the H2KbOVA257–264‐specific Vα2.7 TCR were challenged with influenza to determine how fixing this “irrelevant” TCRα affects the “public” and restricted DbNPCD8+ versus the “private” and diverse DbPACD8+ responses. Though both DbNPCD8+ and DbPACD8+ sets are generated in virus‐primed A7 mice, the constrained DbNPCD8+ population lacked the characteristic, public TCRVβ8.3, and consequently was reduced in magnitude and pMHC‐I avidity. For the more diverse DbPACD8+ T cells, this particular forcing led to a narrowing and higher TCRβ conservation of the dominant Vβ7, though the responses were of comparable magnitude to C57BL/6J controls. Interestingly, although both the TCRβ diversity and the cytokine profiles were reduced for the DbNPCD8+ and DbPACD8+ sets in spleen, the latter measure of polyfunctionality was comparable for T cells recovered from the infected lungs of A7 and control mice. Even “sub‐optimal” TCRαβ pairs can operate effectively when exposed in a milieu of high virus load. Thus, TCRβ diversity is important for optimal TCRαβ pairing and function when TCRα is limiting.
Synthesis, Structure, Characterization, and Redox Properties of the Porous MIL‐68(Fe) Solid
Authors: Fateeva Alexandra , Horcajada Patricia , Devic Thomas , Serre Christian , Marrot Jérôme , Grenèche Jean‐Marc , Morcrette Mathieu , Tarascon Jean‐Marie , Maurin Guillaume , Férey Gérard 
Published: July 2010

AbstractA new porous FeIII‐based MOF, formulated Fe(OH)(BDC)·(dmf)x with x ≈ 1.1 and presenting the MIL‐68 topology, was prepared by reaction of an iron(III) salt and terephthalic acid (H2BDC) in N,N′‐dimethylformamide (dmf) under acidic conditions. The structure and properties of this solid were studied by means of X‐ray diffraction, thermogravimetric analysis, nitrogen sorption, 57Fe Mössbauer spectrometry, and electrochemical lithium insertion.
Experimental and Theoretical Investigation of the Enantiomerization of Lithium α‐tert‐Butylsulfonyl Carbanion Salts and the Determination of Their Structures in Solution and in the Crystal
Authors: Scholz Roland , Hellmann Gunther , Rohs Susanne , Raabe Gerhard , Runsink Jan , Özdemir Diana , Luche Olaf , Heß Thomas , Giesen Alexander W. , Atodiresei Juliana , Lindner Hans J. , Gais Hans‐Joachim 
Published: July 2010

AbstractDynamic NMR (DNMR) spectroscopy of [R1C(R2)SO2R3]Li (R1, R2 = alkyl, phenyl; R3 = Ph, tBu, adamantyl, CEt3) in [D8]THF has shown that the S‐tBu, S‐adamantyl, and S‐CEt3 derivatives have a significantly higher enantiomerization barrier than their S‐Ph analogues. Cα–S bond rotation is most likely the rate‐determining step of the enantiomerization of the salts bearing a bulky group at the S atom and two substituents at the Cα atom. Ab initio calculations on [Me(Ph)SO2tBu]– gave information about the two Cα–S rotational barriers, which are dominated by steric effects. Cryoscopy of [R1C(R2)SO2tBu]Li in THF at –108 °C revealed the existence of monomers and dimers. X‐ray crystal structure analysis of the monomers and dimers of [R1C(R2)SO2tBu]Li·Ln (R1 = Me, Et, tBuCH2, PhCH2, tBu; R2 = Ph, L = THF, 12‐crown‐4, PMDTA) and [R1C(R2)SO2Ph]Li·2diglyme [R1 = R2 = Me, Et; R1–R2 = (CH2)5] showed them to be O–Li contact ion pairs (CIPs). The monomers and dimers have a Cα–S conformation in which the lone‐pair orbital at the Cα atom bisects the O–S–O angle and a significantly shortened Cα–S bond. The Cα atom of [R1C(R2)SO2R3]Li·Ln (R1 = Ph; R3 = Ph, tBu) is planar, whereas the Cα atom of [R1C(R2)SO2R3]Li·Ln (R1 = R2 = alkyl) is strongly pyramidalized in the case of R3 = Ph and most likely planar for R3 = tBu. Ab initio calculations on [MeC(Me)SO2R]– gave a pyramidalized Cα atom for R = Me and a nearly planar one for R = CF3 and tBu. The [R1C(R2)SO2tBu]Li salts were characterized by 1H, 13C, and 6Li NMR spectroscopy. 1H{1H} and 6Li{1H} NOE experiments are in accordance with the existence of O–Li CIPs. 1H and 13C NMR spectroscopy of [R1C(R2)SO2tBu]Li in [D8]THF at low temperatures showed equilibrium mixtures of up to five different species being most likely monomeric and dimeric O–Li CIPs with different configurations. According to 7Li NMR spectroscopy, the addition of HMPA to [MeC(Ph)SO2tBu]Li in [D8]THF at low temperatures causes the formation of the separated ion pair [MeC(Ph)SO2tBu]Li(HMPA)4.
Wirkungsvoll bis ins hohe Alter
Authors: Berger Christina 
Published: July 2010

AbstractFossil betriebene Kraftwerke bleiben wichtige Bausteine moderner Energieversorgung. Auch die neuesten Anlagen sind auf mindestens 30 Jahre ausgelegt. Sie sollen die Wärme noch besser und sauberer in Energie umwandeln. Wissenschaft und Wirtschaft entwickeln dafür innovative Bauteile. Ihre Vision: Kraftwerke mit „Nahe‐Null‐Emmission”︁
Chronik einer missachteten Gewissheit
Authors: Rahmstorf Stefan 
Published: July 2010

AbstractSchon seit 150 Jahren kennen Wissenschaftler den Treibhauseffekt. Ausmaß und Folgen der Erderwärmung werden seitdem immer genauer beschrieben. Doch Politik, Wirtschaft und Gesellschaft haben alle Warnungen nicht ernst genug genommen. Heute sind die Optionen für eine klimafreundlichere Gewinnung und Nutzung von Energie klarer denn je – aber die Zeit für ihre Umsetzung läuft davon.
Die Gasometer von morgen
Authors: Schüth Ferdi 
Published: July 2010

AbstractRegenerative Energie steht weder ständig noch gleichmäßig zur Verfügung – sie zu speichern, wird deshalb immer wichtiger. Solarthermische Kraftwerke, Metall‐Luft‐Batterien oder energiereiche chemische Verbindungen wie Methan bieten langfristig Große Potenziale. Vorerst sind sie vor allem eine Herausforderung für die Forschung.
Der selbstsüchtige Energiefresser im Kopf
Authors: Peters Achim 
Published: July 2010

AbstractAuch für den menschlichen Organismus sind Störungen im Energiekreislauf eine Gefahr: Wenn das Gehirn seinen Glukosebedarf aus dem Körper nicht decken kann, gibt es den Befehl zu sofortiger Nahrungsaufnahme – Übergewicht und Diabetes können die Folge sein.
Management of chronic pain: current and future options
Authors: Searle Robert , Simpson Karen 
Published: July 2010

AbstractChronic pain is surprisingly prevalent and, if left untreated, can lead to significant limitations for the sufferer including restricted mobility and possible job loss. Pain has also been shown to be the reason for 40% of patient visits to GPs each year. This results in a substantial economic burden not only for those involved but also for the wider economy. Here we review the current options for pain management and look at new treatments in the pipeline. Copyright © 2010 John Wiley & Sons, Ltd.