bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel type of complex ganglion cell in rabbit retina
Authors: Sivyer Benjamin , Venkataramani Sowmya , Taylor W. Rowland , Vaney David I. 
Published: September 2011

AbstractThe 15–20 physiological types of retinal ganglion cells (RGCs) can be grouped according to whether they fire to increased illumination in the receptive‐field center (ON cells), decreased illumination (OFF cells), or both (ON‐OFF cells). The diversity of RGCs has been best described in the rabbit retina, which has three types of ON‐OFF RGCs with complex receptive‐field properties: the ON‐OFF direction‐selective ganglion cells (DSGCs), the local edge detectors, and the uniformity detectors. Here we describe a novel type of bistratified ON‐OFF RGC that has not been described in either physiological or morphological studies of rabbit RGCs. These cells stratify in the ON and OFF sublaminae of the inner plexiform layer, branching at about 30% and 60% depth, between the ON and OFF arbors of the bistratified DSGCs. Similar to the ON‐OFF DSGCs, these cells respond with transient firing to both bright and dark spots flashed in the receptive field but, unlike the DSGCs, they show no directional preference for moving stimuli. We have termed these cells “transient ON‐OFF” RGCs. Area‐response measurements show that both the ON and the OFF spike responses have an antagonistic receptive‐field organization, but with different spatial extents. Voltage‐clamp recordings reveal transient excitatory inputs at light ON and light OFF; this excitation is strongly suppressed by surround stimulation, which also elicits direct inhibitory inputs to the cells at light ON and light OFF. Thus the receptive‐field organization is mediated both within the presynaptic circuitry and by direct feed‐forward inhibition. J. Comp. Neurol. 519:3128–3138, 2011. © 2011 Wiley‐Liss, Inc.
A Robust Yellow‐Emitting Metallophosphor with Electron‐Injection/‐Transporting Traits for Highly Efficient White Organic Light‐Emitting Diodes
Authors: Zhou Guijiang , Yang Xiaolong , Wong Wai‐Yeung , Wang Qi , Suo Si , Ma Dongge , Feng Jikang , Wang Lixiang 
Published: September 2011

AbstractWith the aim of endowing triplet emitters in the development of organic light‐emitting devices (OLEDs) with electron‐injection/‐transporting (EI/ET) features, the phenylsulfonyl moiety was introduced into the phenyl ring of a 2‐phenylpyridine (Hppy) ligand and the yellow phosphorescent heteroleptic iridium(III) complex 1 was developed. It was shown that the SO2Ph unit could provide EI/ET character to 1, as indicated from both electrochemical and computational data. Complex 1 is a promising yellow‐emitting material for both monochromatic OLEDs and white OLEDs (WOLEDs). The outstanding electronic traits associated with 1, coupled with careful device design, afforded very attractive electroluminescent performances for two‐element WOLEDs, including a low turn‐on voltage of less than 3.7 V, a maximum brightness of 48 000 cd m−2, an external quantum efficiency of 13.0 %, a luminance efficiency of 34.7 cd A−1, and a power efficiency of 24.3 Lm W−1. In addition, a good color rendering index (CRI) of about 74, a stable white color with a Commission Internationale de L′Eclairage (CIEx,y) variation of Δ(x, y)<±(0.02, 0.02), and a correlated color temperature higher than 5130 K were obtained. These encouraging results indicate the potential of these WOLEDs as good candidates for warm indoor lighting sources, as well as the critical contribution of such key EI/ET properties to triplet emitters to advance new OLED research.
Host–Guest Interaction of Hoechst 34580 and Cucurbit[7]uril
Authors: Lei Wanhua , Zhou Qianxiong , Jiang Guoyu , Hou Yuanjun , Zhang Baowen , Cheng Xuexin , Wang Xuesong 
Published: September 2011

AbstractTo track nuclear dynamic processes by fluorescence imaging, nuclear stains should be highly fluorescent, resistant to photobleaching, and inert to nuclear processes. The nuclear stains of the Hoechst family, such as Hoechst 34580, show bright fluorescence only on groove binding to DNA, and therefore may interfere with visualization of nuclear dynamic processes induced by other stimuli. We study host–guest interactions between Hoechst 34580 and Cucurbit[7]uril (CB7) in aqueous solutions. The formation of CB7–Hoechst 34580 inclusion complexes with stoichiometry of 2:1 in water and 1:1 in phosphate‐buffered saline (PBS) solution (pH 7.0) is confirmed by 1H NMR, absorption spectra, fluorescence spectra, MALDI‐TOF MS, and molecular modeling. Compared to Hoechst 34580, the inclusion complex exhibits redshifted absorption, intensified fluorescence, improved photostability, weakened DNA binding affinity, comparable ability to penetrate cell nuclei, and better nuclear‐staining capability, and thus a new avenue for the application of cucurbituril in fluorescence imaging is opened.
Coupled‐Cluster Calculations of Vibrational Raman Optical Activity Spectra
Authors: Crawford T. Daniel , Ruud Kenneth 
Published: September 2011

AbstractWe present the first calculations of Raman optical activity spectra at the coupled‐cluster level of theory. Calculations are presented for (S)‐methyloxirane and compared to recent experimental gas‐phase measurements as well as the results obtained at the Hartree–Fock and density functional level of theory using the popular B3LYP functional. For the experimentally relevant frequency region of 400–1600 cm−1, the Hartree–Fock, B3LYP and coupled‐cluster spectra are very similar when the same force field is used, and the results also agree well with experiment. For high‐frequency vibrational modes, differences in the ROA difference parameters are observed and are analyzed. The new coupled‐cluster ROA code will allow for critical benchmarking of the accuracy of modern exchange–correlation functionals in the calculation of ROA spectra.
The Effect of Zinc Addition on the Oxidation State of Cobalt in Co/ZrO2 Catalysts
Authors: Lebarbier Vanessa M. , Karim Ayman M. , Engelhard Mark H. , Wu Yu , Xu Bo‐Qing , Petersen Eric J. , Datye Abhaya K. , Wang Yong 
Published: September 2011

AbstractThe effect of zinc promotion on the oxidation state of cobalt in Co/ZrO2 catalysts was investigated and correlated with the activity and selectivity for ethanol steam reforming (ESR). Catalysts were synthesized by applying incipient wetness impregnation and characterized by using Brunauer–Emmett–Teller (BET), temperature‐programmed reduction (TPR) measurements, X‐ray diffraction (XRD), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS). Higher ethanol conversion and lower CH4 selectivity are observed for the Co/ZrO2 catalyst promoted with Zn as compared to the Co/ZrO2 catalyst alone. Addition of Zn inhibits the oxidation of metallic cobalt (Co0) particles and results in a higher ratio of Co0/Co2+ in the Zn‐promoted Co/ZrO2 catalyst. These results suggest that metallic cobalt (Co0) is more active than Co2+ in the ethanol conversion through dehydrogenation and that Co2+ may play a role in the CH4 formation. TPR measurements, on the other hand, reveal that Zn addition inhibits the reduction of Co2+ and Co3+, which would lead to the false conclusion that oxidized Co is required to reduce the CH4 formation. Therefore, TPR measurements may not be appropriate to correlate the degree of metal reducibility (in this case Co0) with the catalyst activity for reactions, such as ESR, where oxidizing conditions exist.
The roles of the cadherins Fat and Dachsous in planar polarity specification in Drosophila
Authors: Thomas Chloe , Strutt David 
Published: September 2011

AbstractPlanar polarity is generated through the activity of two groups of proteins, the “core” system and the Fat (Ft)/Dachsous (Ds) system. Although both are conserved from insects to mammals, vertebrate studies into planar polarity have primarily focussed on core planar polarity proteins and have only recently branched into the study of the Ft/Ds system. In Drosophila, however, years of detailed analysis have started to elucidate some of the mechanisms by which Ft/Ds signalling might set up polarity across a tissue, and how this may impact upon core protein‐mediated planar polarity. In this review, we discuss the major findings, models, and controversies that have emerged from Drosophila research into the Ft/Ds system, and indicate some areas for further investigation. Developmental Dynamics 241:27–39, 2012. © 2011 Wiley Periodicals, Inc.
A Porphyrin‐Bridged Pd Dimer Complex Stabilizes Gold Nanoparticles
Authors: Fratoddi Ilaria , Battocchio Chiara , Polzonetti Giovanni , Sciubba Fabio , Delfini Maurizio , Russo Maria Vittoria 
Published: September 2011

AbstractA porphyrin‐bridged bimetallic palladium(II) diphenylacetylide complex and the oligomer with 3–5 repeat units have been prepared and spectroscopically characterized. The porphyrin‐bridged Pd complex has been used for the stabilization of gold nanoparticles, thus giving rise to unexpected stable structures with no evidence of covalent bonds between the porphyrin and the gold nanoparticles. The morphology investigated by TEM analysis shows that gold nanoparticles with a mean diameter of about 5 nm have been obtained. UV/Vis spectra reveal the achievement of stabilized gold nanoparticles through the presence of the plasmon resonance at 500 nm together with the absorption features of the porphyrin molecule at 436 and 620 nm (Q band). Photoluminescence spectra exhibit an emission feature centred at 572 nm with a shoulder at 325 nm with no quenching effects. XPS measurements at the Au 4f core level suggest an electronic interaction between the gold atoms of the nanoparticle surface and the porphyrin‐based complex; NMR spectroscopic studies indicate that interactions and assemblies also occur that involve the porphyrin rings. Elemental analysis suggests that about 120 tilted porphyrins are physisorbed onto the Au core.
An Ionic Liquid Designed for Coordination Chemistry Revisited: Synthetic Routes and Safety Tests for 1‐Ethyl‐3‐methylimidazolium Perchlorate ([emim][ClO4])
Authors: Schmeisser Matthias , Keil Philipp , Stierstorfer Jörg , König Axel , Klapötke Thomas M. , van Eldik Rudi 
Published: September 2011

AbstractThe colourless room‐temperature ionic liquid 1‐ethyl‐3‐methylimidazolium perchlorate, [emim][ClO4], was revisited for reasons of its hydrophilic character and its weak coordinating ability. In this study, [emim][ClO4] was synthesized from the cheaper ionic liquid 1‐ethyl‐3‐methylimidazolium ethyl sulfate, [emim][EtSO4], by way of direct and indirect membrane‐assisted anion metathesis. Both synthetic methods, as alternatives to the metathesis of silver perchlorate and [emim] halides, are compared and discussed in detail. In addition, some physicochemical parameters were determined to characterize the ionic liquid. With respect to the hazardous nature of organic perchlorates, the thermal stability as well as the impact and friction sensitivity of [emim][ClO4] were tested according to the UN Test Series 3a–3d.
1D CoII and NiII Chiral Polymers That Exhibit Ferromagnetic Interactions
Authors: Novitchi Ghenadie , Pilet Guillaume , Luneau Dominique 
Published: September 2011

AbstractFour transition‐metal coordination compounds with d‐ and L‐mandelic acid (Hmand) were synthesized and structurally and magnetically characterized. The structure, refined as {MII(L/D‐mand)(4‐MePy)3}n·n(ClO4) (M = CoII and NiII; 4‐MePy = 4‐methylpyridine), reveals a chiral 1D polymer that consists of a chain complex built by the monocarboxylate ligand. The coordination sphere of the paramagnetic center is chiral and completed by three 4Me–Py ligands. Magnetic studies reveal the presence of a ferromagnetic interaction between the NiII centers [J = 0.64(5)–0.54(7) cm–1 and zero‐field splitting (ZFS) = –1.38(1)/–1.05(2) cm–1]. In the case of the CoII‐based polymer, ferromagnetic but negligible interaction is suspected.
First Acid‐Catalyzed Entry to O‐Alkylated Hydroximides from Benzylic Alcohols
Authors: Reddy Chada Raji , Radhika Laghuvarapu , Kumar Togapur Pavan , Chandrasekhar Srivari 
Published: September 2011

AbstractA facile method for the synthesis of O‐alkylated hydroximides through the acid‐catalyzed alkylation of hydroximides by using benzylic alcohols as alkylating agents is described for the first time. The obtained O‐propargylated products offered easy access to 2,5‐ and 4,5‐dihydroisoxazoles.
Metal‐Free Oxidative Coupling Reactions via σ‐Iodonium Intermediates: The Efficient Synthesis of Bithiophenes Using Hypervalent Iodine Reagents
Authors: Morimoto Koji , Nakae Tomofumi , Yamaoka Nobutaka , Dohi Toshifumi , Kita Yasuyuki 
Published: September 2011

AbstractThe direct oxidative biaryl coupling reaction is an attractive tool for environmentally benign green chemistry. A novel direct method for the synthesis of bithiophene using a hypervalent iodine reagent has been developed. The reaction mechanism has also been investigated, casting light on the reaction intermediate and revealing the reactivity with iodonium salts.
A New Synthetic Approach to Efavirenz through Enantioselective Trifluoromethylation by Using the Ruppert–Prakash Reagent
Authors: Kawai Hiroyuki , Kitayama Takashi , Tokunaga Etsuko , Shibata Norio 
Published: September 2011

AbstractThe organocatalyzed asymmetric synthesis of efavirenz was achieved in five steps from a commercially available substrate through the operationally simple, enantioselective trifluoromethylation of an alkynyl ketone by using the Ruppert–Prakash reagent. The present method provides the first example of the enantioselective synthesis of efavirenz by using a direct trifluoromethylation approach.
A level set method to study foam processing: a validation study
Authors: Rao Rekha R. , Mondy Lisa A. , Noble David R. , Moffat Harry K. , Adolf Douglas B. , Notz P.K. 
Published: September 2011

SUMMARYWe have developed a production‐level foam processing computational model suitable for predicting the self‐expansion of foam in complex geometries. The model is based on a finite element representation of the equations of motion, with the movement of the free surface represented using the level set method. An empirically based time‐dependent and temperature‐dependent density model is used to encapsulate the complex physics of foam nucleation and growth in a numerically tractable manner. The evolving density drives the dynamics of foam self‐expansion. This continuum‐level model uses a homogenized description of foam, which does not include the gas explicitly, but allows varying local fields, such as temperature and gas volume fraction, and material models. In addition, material models vary with the location of the level set interface, taking properties of the displaced air phase in the negative level set region and the foam in the positive region. The level set zero describes the location of the interface, where surface forces are applied using the continuous surface force treatment. The variation from foam to gas properties is handled with a diffuse interface method using a smooth Heaviside function and equation averaging. Material model development was guided and populated by careful experiments. Results from the model are compared with temperature‐instrumented flow visualization experiments giving the location of the foam front as a function of time for a physically blown, epoxy foam. Good qualitative agreement is seen between simulations and experiments, although some of the subtleties of the filling process are lost to the model. Published 2011. This article is a US Government work and is in the public domain in the USA.
Role of platelet‐derived growth factor‐AB in tumour growth and angiogenesis in relation with other angiogenic cytokines in multiple myeloma
Authors: Tsirakis George , Pappa Constantina A. , Kanellou Peggy , Stratinaki Maria A. , Xekalou Athina , Psarakis Fotios E. , Sakellaris George , Alegakis Athanasios , Stathopoulos Efstathios N. , Alexandrakis Michael G. 
Published: September 2011

AbstractAngiogenesis is a complex process essential for the growth, invasion, and metastasis of various malignant tumours, including multiple myeloma (MM). Various angiogenic cytokines have been implicated in the angiogenic process. Among them, platelet‐derived growth factor‐AB (PDGF‐AB) has been reported to be a potent stimulator of angiogenesis in many solid tumours and haematological malignancies, including MM. The aim of the study was to investigate the relationship between PDGF‐AB, microvascular density (MVD), and various angiogenic cytokines, such as basic fibroblast growth factor (b‐FGF), angiogenin (ANG), and interleukin‐6 (IL‐6), in MM patients. Forty‐seven MM patients before treatment, 22 of whom were in plateau phase, were studied. We determined the serum levels of the aforementioned cytokines and MVD in bone marrow biopsies before and after treatment. Mean serum values of PDGF‐AB, b‐FGF, ANG, and MVD were significantly higher in patients compared with controls and with increasing disease stage. Significant positive correlations were observed between serum PDGF‐AB, ANG, and IL‐6 levels and MVD. Furthermore, we found significant positive correlations between PDGF‐AB and b‐FGF, IL‐6, ANG, and β2 microglobulin. We also found that patients with high MVD had statistically significantly higher serum levels of PDGF‐AB when a median MVD value of 7.7 was used as the cutoff point. Furthermore, a significant difference was found in serum levels of PDGF‐AB between pre‐ and post‐treatment patients. Finally, survival time was significantly higher in the low MVD group versus the high MVD group (76 vs 51 months). Our results showed that there is a strong positive correlation between PDGF‐AB and the studied angiogenic cytokines and MVD. It seems that PDGF‐AB plays a role in the complex network of cytokines inducing bone marrow neovascularization in patients with MM. Copyright © 2011 John Wiley & Sons, Ltd.
A dual‐targeting antibody against EGFR‐VEGF for lung and head and neck cancer treatment
Authors: Zhang Hongzheng , Yun Sujin , Batuwangala Thil D. , Steward Michael , Holmes Steve D. , Pan Lin , Tighiouart Mourad , Shin Hyung Ju C. , Koenig Lydia , Park Wungki , Rycroft Daniel , Nannapaneni Sreenivas , Wang Yuxiang , Chen Zhuo (Georgia) , Shin Dong M. 
Published: September 2011

AbstractAn antibody simultaneously targeting epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF), two major tumor growth‐driving machineries, may provide a novel effective strategy for optimizing tumor targeting and maximizing potential clinical benefits. Human domain antibodies selected against VEGF and EGFR were formatted into a fully human dual‐targeting IgG (DT‐IgG) to directly target both antigens in a single molecule. We evaluated the efficacy of DT‐IgG in comparison with bevacizumab and cetuximab alone and in combination in the lung cancer cell line A549 (low EGFR expression and KRAS mutant) and the head and neck squamous cell carcinoma (HNSCC) cell line Tu212 (high EGFR expression and KRAS wild type) in vitro and in vivo. DT‐IgG suppressed Tu212 and A549 cell growth, inhibited EGFR activation and induced apoptosis as effectively as cetuximab, and neutralized VEGF as effectively as bevacizumab. DT‐IgG induced EGFR‐dependent VEGF internalization, constituting a novel antiangiogenesis mechanism. In xenograft models with lung and head and neck cancer cell lines, DT‐IgG displayed efficacy equivalent to bevacizumab in diminishing tumor growth despite its short serum half‐life (36 hr in rats) and both agents may constitute preferable alternatives to cetuximab in KRAS‐mutant tumors. Immunofluorescence staining revealed that localization of DT‐IgG was similar to that of cetuximab, largely associated with EGFR+tumor cells. Our proof of principle study suggests a DT‐IgG against EGFR and VEGF as an alternative therapeutic strategy with potentially enhanced clinical benefit.
KSHV activation of VEGF secretion and invasion for endothelial cells is mediated through viral upregulation of emmprin‐induced signal transduction
Authors: Dai Lu , Bratoeva Momka , Toole Bryan P. , Qin Zhiqiang , Parsons Chris 
Published: September 2011

AbstractKaposi's sarcoma‐associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS)—one of the most common tumors arising in the setting of immune suppression. Hallmarks of KS lesions include KSHV‐infected cells of endothelial lineage and neoangiogenesis. Promigratory factors secreted in the tumor microenvironment by KSHV‐infected cells promote endothelial cell (EC) migration and angiogenesis but existing therapies targeting these pathways are not widely utilized. This underscores the need for additional characterization of KSHV‐host interactions relevant to EC pathogenesis to identify new therapeutic targets. We recently demonstrated that de novo infection by KSHV promotes EC invasion through upregulation of extracellular matrix metalloproteinase inducer (emmprin)—a multifunctional glycoprotein previously shown to induce tumor cell invasion and regional angiogenesis through upregulation of signal transduction and promotion of tumor‐stroma interactions. This study was undertaken to determine whether EC invasion for KSHV‐infected cells is induced through activation of specific signal transduction pathways and proangiogenic factors by emmprin. We found that KSHV activation of emmprin induces PI3K/Akt‐ and mitogen‐activated protein kinase (MAPK)‐dependent secretion of vascular endothelial growth factor (VEGF). Functionally, EC invasion following de novo infection is induced by emmprin‐dependent PI3K/Akt and MAPK activation of VEGF. These findings support the potential utility of targeting emmprin for reducing VEGF secretion and EC migration in the KS microenvironment.
Quantitative analyses of DAPK1 methylation in AML and MDS
Authors: Claus Rainer , Hackanson Björn , Poetsch Anna R. , Zucknick Manuela , Sonnet Miriam , Blagitko‐Dorfs Nadja , Hiller Jan , Wilop Stefan , Brümmendorf Tim H. , Galm Oliver , Platzbecker Uwe , Byrd John C. , Döhner Konstanze , Döhner Hartmut , Lübbert Michael , Plass Christoph 
Published: September 2011

AbstractAberrant DNA methylation and concomitant transcriptional silencing of death‐associated protein kinase 1 (DAPK1) have been demonstrated to be key pathogenic events in chronic lymphocytic leukemia (CLL). In acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), however, the presence of elevated DNA methylation levels has been a matter of continued controversy. Several studies demonstrated highly variable frequencies of DAPK1 promoter methylation by the use of methylation‐specific PCR (MSP). By quantitative high‐resolution assessment, we demonstrate that aberrant DNA methylation is an extremely rare event in this region. We observed elevated levels just in one out of 246 (0.4%) AML patients, all 42 MDS patients were unmethylated. In conclusion, we present a refined DAPK1 methylation analysis in a large representative patient cohort of AML and MDS patients proofing almost complete absence of elevated DNA methylation. Our results highlight the importance of quantitative measurements for translational research questions on primary patient specimens, particularly.