bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction of a Selective Fluorescent Probe for GSH Based on a Chloro‐Functionalized Coumarin‐enone Dye Platform
Authors: Liu Yawei , Lv Xin , Liu Jing , Sun Yuan‐Qiang , Guo Wei 
Published: February 2015

AbstractGlutathione (GSH), the most abundant intracellular biothiol, protects cellular components from damage caused by free radicals and reactive oxygen species (ROS), and plays a crucial role in human pathologies. A fluorescent probe that can selectively sense intracellular GSH would be very valuable for understanding of its biological functions and mechanisms of diseases. In this work, a 3,4‐dimethoxythiophenol‐substituted coumarin‐enone was exploited as a reaction‐type fluorescent probe for GSH based on a chloro‐functionalized coumarin‐enone platform. In the probe, the 3,4‐dimethoxythiophenol group functions not only as a fluorescence quencher through photoinduced electron transfer (PET) to ensure a low background fluorescence, but also as a reactive site for biothiols. The probe displays a dramatic fluorescence turn‐on response toward GSH with the long‐wavelength emission (600 nm) and significant Stokes shift (100 nm). The selectivity of the probe toward GSH over cysteine (Cys), homocysteine (Hcy), and other amino acids was demonstrated. Assisted by laser‐scanning confocal microscopy, we have demonstrated that the probe could specifically sense GSH over Cys/Hcy in human renal cell carcinoma SiHa cells.
How a Redox‐Innocent Metal Promotes the Formal Reductive Elimination of Biphenyl Using Redox‐Active Ligands
Authors: Ashley Daniel Charles , Baik Mu‐Hyun 
Published: February 2015

AbstractOne of the most compelling strategies for utilizing redox‐active ligands is to perform redox events at the ligands to avoid accessing prohibitively high energy oxidation states at the metal center. This has been demonstrated experimentally in many systems, yet there is little understanding of the fundamental electronic structures involved with these transformations or how to control them. Here, the reductive elimination of biphenyl from [M(isq)2Ph2] (M=Ti, Zr, and Hf and isq=2,4‐di‐tert‐butyl‐6‐tert‐butyliminosemiquinone) was studied computationally. It was found that the metal remains in the +IV oxidation state and all redox chemistry was mediated by the redox‐active ligands. Two types of electron‐transfer mechanisms were identified, an asymmetric unpaired electron transfer (UET) and a symmetric pairwise electron transfer (PET), the former always being lower in energy. The energetic differences between these two mechanisms were explained through simple molecular orbital theory arguments. Despite the metal’s redox‐inactivity, it still has a marked influence on the calculated energetics of the reaction, with the Ti systems being much more reactive than the Zr/Hf systems. This primarily originates from the shorter TiPh bond, which leads to a stronger filled‐filled interaction between these ligands at the reactant state. This greater reactant destabilization leads to the lower activation energies.
Two Heterometallic–Organic Frameworks Composed of Iron(III)‐Salen‐Based Ligands and d10 Metals: Gas Sorption and Visible‐Light Photocatalytic Degradation of 2‐Chlorophenol
Authors: Li Jing , Yang Jin , Liu Ying‐Ying , Ma Jian‐Fang 
Published: February 2015

AbstractTwo examples of heterometallic–organic frameworks (HMOFs) composed of dicarboxyl‐functionalized FeIII‐salen complexes and d10 metals (Zn, Cd), [Zn2(Fe‐L)2(μ2‐O)(H2O)2]⋅4 DMF⋅4 H2O (1) and [Cd2(Fe‐L)2(μ2‐O)(H2O)2]⋅2 DMF ⋅H2O (2) (H4L=1,2‐cyclohexanediamino‐N,N′‐bis(3‐methyl‐5‐carboxysalicylidene), have been synthesized and structurally characterized. In 1 and 2, each square‐pyramidal FeIII atom is embedded in the [N2O2] pocket of an L4− anion, and these units are further bridged by a μ2‐O anion to give an (Fe‐L)2(μ2‐O) dimer. The two carboxylate groups of each L4− anion bridge ZnII or CdII atoms to afford a 3D porous HMOF. The gas sorption and magnetic properties of 1 and 2 have been studied. Remarkably, 1 and 2 show activity for the photocatalytic degradation of 2‐chlorophenol (2‐CP) under visible‐light irradiation, which, to the best of our knowledge, is the first time that this has been observed for FeIII‐salen‐based HMOFs.
Gold(I)‐Catalyzed Intramolecular Cycloisomerization of Propargylic Esters with Furan Rings
Authors: Yang Jin‐Ming , Tang Xiang‐Ying , Shi Min 
Published: February 2015

AbstractA gold‐catalyzed intramolecular cycloisomerization of α‐yne‐furans 1 is described in this contribution. A variety of cyclic α,β‐unsaturated aldehyde or ketone derivatives and nitrogen‐containing tricyclic adducts were obtained selectively in moderate to excellent yields under mild conditions by varying the substituents on the standard substrates.
Syngas and Synfuels from H2O and CO2: Current Status
Authors: Nguyen Van Nhu , Blum Ludger 
Published: February 2015

AbstractHydrogen and synthesis gas (syngas) production from water and carbon dioxide as well as fuel processing for fuel cells and for transport applications have great potential in addressing major challenges in the area of energy. This review highlights recent progress and future trends on energy storage via carbon‐neutral fuels made from water, carbon dioxide and renewable energies. The various electrochemical, thermochemical and photochemical energy conversion technologies for dissociation of H2O or/and CO2are reviewed and discussed systematically.
Dry Reforming and Reverse Water Gas Shift: Alternatives for Syngas Production?
Authors: Schwab Ekkehard , Milanov Andrian , Schunk Stephan Andreas , Behrens Axel , Schödel Nicole 
Published: February 2015

AbstractDry reforming and reverse water gas shift are often discussed as potential carbon dioxide sinks. They may in the near future act as enablers for improving carbon footprints of certain value chains. In this paper, it will be critically discussed in short format why both technologies can only be operated economically and sustainably in defined contexts. A number of technical and economic challenges of both reactions are discussed and potential solutions for technical realization are presented.
Luminescent Properties of a Water‐Soluble Conjugated Polymer Incorporating Graphene‐Oxide Quantum Dots
Authors: Li Penglei , Di Stasio Francesco , Eda Goki , Fenwick Oliver , McDonnell Shane O. , Anderson Harry L. , Chhowalla Manish , Cacialli Franco 
Published: February 2015

AbstractWe report the incorporation of graphene‐oxide quantum dots (GOQDs) into films, diluted solutions, and light‐emitting diodes (LEDs) as part of a water‐soluble derivative of poly(p‐phenylene vinylene), or PDV.Li, to investigate their impact on the light‐emission properties of this model conjugated polymer. Despite the well‐known ability of graphene and graphene oxide to quench the photoluminescence of nearby emitters, we find that the addition of GOQDs to diluted solutions of PDV.Li does not significantly affect the photoluminescence (PL) dynamics of PDV.Li, bringing about only a modest quenching of the PL. However, loading the polymer with GOQDs led to a substantial decrease in the turn‐on voltage of LEDs based on GOQD–PDV.Li composites. This effect can be attributed to either the improved morphology of the host polymer, resulting in an increase in the charge mobility, or the enhanced injection through GOQDs near the electrodes.
Ultrafast Charge‐Transfer Reactions of Indoline Dyes with Anchoring Alkyl Chains of Varying Length in Mesoporous ZnO Solar Cells
Authors: Rohwer Egmont , Minda Iulia , Tauscher Gabriele , Richter Christoph , Miura Hidetoshi , Schlettwein Derck , Schwoerer Heinrich 
Published: February 2015

AbstractDye‐sensitized solar cells based on a mesoporous ZnO substrate were sensitized with the indoline derivatives DN91, DN216 and DN285. The chromophore is the same for each of these dyes. They differ from each other in the length of an alkyl chain, which provides a second anchor to the ZnO surface and prolongs cell lifetime. Ultrafast transient absorption measurements reveal a correlation between the length of the alkyl chain and the fastest electron‐injection process. The depopulation of the excited state and the associated emergence of the oxidized molecules are dominant spectral features in the transient absorption of the dyes with shorter alkyl chains. A slower picosecond‐scale decay proceeds at constant rate for all three derivatives and is assigned to electron transfer into the trap states of ZnO. All assignments are in good agreement with a higher quantum efficiency of charge injection leading to higher short‐circuit currents Jsc for dyes with shorter alkyl chains.
Dense or Porous Packing? Two‐Dimensional Self‐Assembly of Star‐Shaped Mono‐, Bi‐, and Terpyridine Derivatives
Authors: Trawny Daniel , Schlexer Philomena , Steenbergen Krista , Rabe Jürgen P. , Paulus Beate , Reissig Hans‐Ulrich 
Published: February 2015

AbstractThe self‐assembly behavior of five star‐shaped pyridyl‐functionalized 1,3,5‐triethynylbenzenes was studied at the interface between an organic solvent and the basal plane of graphite by scanning tunneling microscopy. The mono‐ and bipyridine derivatives self‐assemble in closely packed 2D crystals, whereas the derivative with the more bulky terpyridines crystallizes with porous packing. DFT calculations of a monopyridine derivative on graphene, support the proposed molecular model. The calculations also reveal the formation of hydrogen bonds between the nitrogen atoms and a hydrogen atom of the neighboring central unit, as a small nonzero tunneling current was calculated within this region. The title compounds provide a versatile model system to investigate the role of multivalent steric interactions and hydrogen bonding in molecular monolayers.
Activation of Ultrathin Films of Hematite for Photoelectrochemical Water Splitting via H2 Treatment
Authors: Moir Jonathon , Soheilnia Navid , Liao Kristine , O'Brien Paul , Tian Yao , Burch Kenneth S. , Ozin Geoffrey A. 
Published: February 2015

AbstractThermal treatment of ultrathin films of hematite (α‐Fe2O3) under an atmosphere of 5 % H2 in Ar is presented as a means of activating α‐Fe2O3 towards the photoelectrochemical splitting of water. Spin‐coated films annealed in air exhibited no photoactivity, whereas films treated in hydrogen exhibited a photocurrent response. X‐ray photoelectron spectroscopy and UV/Vis absorption spectroscopy results showed that the H2‐treated films contain oxygen vacancies, which suggests improved charge transport. However, Tafel slopes, scan‐rate dependent measurements, and kinetic analyses performed by using H2O2 as a hole scavenger suggested that surface modification may also contribute to their induced photoactivity. Electrochemical impedance spectroscopy results revealed the buildup of a surface trap capacitance at the point of photocurrent onset for the hydrogen‐treated films under illumination. A decrease in charge trapping resistance was also observed, which suggests improved transport of charges away from the surface.
Co‐Adsorbents: A Key Component in Efficient and Robust Dye‐Sensitized Solar Cells
Authors: Manthou Victoria S. , Pefkianakis Eleftherios K. , Falaras Polycarpos , Vougioukalakis Georgios C. 
Published: February 2015

AbstractSince the establishment of dye‐sensitized solar cells in the early ‘90s, both the efficiency and stability of these third generation photovoltaics have been greatly enhanced. Nevertheless, there still exist many unwanted processes that impede operation of dye‐sensitized solar cells, encumbering the achievement of the maximum theoretical power conversion efficiency and decreasing the devices’ long‐term operation. These processes include charge recombination, dye aggregation, dye desorption, and high protonation degrees of the semiconductor’s surface. This Minireview focuses on a powerful strategy developed to address these problems, namely the use of co‐adsorbents. All types of co‐adsorbents utilized thus far are categorized in terms of the chemical identity of their anchoring group; in addition their operational mechanisms are presented and the properties that a functional molecule should possess to be applied as an efficient co‐adsorbent are discussed.
Hindsight regulates photoreceptor axon targeting through transcriptional control of jitterbug/Filamin and multiple genes involved in axon guidance in Drosophila
Authors: Oliva Carlos , Molina‐Fernandez Claudia , Maureira Miguel , Candia Noemi , López Estefanía , Hassan Bassem , Aerts Stein , Cánovas José , Olguín Patricio , Sierralta Jimena 
Published: February 2015

ABSTRACTDuring axon targeting, a stereotyped pattern of connectivity is achieved by the integration of intrinsic genetic programs and the response to extrinsic long and short‐range directional cues. How this coordination occurs is the subject of intense study. Transcription factors play a central role due to their ability to regulate the expression of multiple genes required to sense and respond to these cues during development. Here we show that the transcription factor HNT regulates layer‐specific photoreceptor axon targeting in Drosophila through transcriptional control of jbug/Filamin and multiple genes involved in axon guidance and cytoskeleton organization.Using a microarray analysis we identified 235 genes whose expression levels were changed by HNT overexpression in the eye primordia. We analyzed nine candidate genes involved in cytoskeleton regulation and axon guidance, six of which displayed significantly altered gene expression levels in hnt mutant retinas. Functional analysis confirmed the role of OTK/PTK7 in photoreceptor axon targeting and uncovered Tiggrin, an integrin ligand, and Jbug/Filamin, a conserved actin‐ binding protein, as new factors that participate of photoreceptor axon targeting. Moreover, we provided in silico and molecular evidence that supports jbug/Filamin as a direct transcriptional target of HNT and that HNT acts partially through Jbug/Filamin in vivo to regulate axon guidance. Our work broadens the understanding of how HNT regulates the coordinated expression of a group of genes to achieve the correct connectivity pattern in the Drosophila visual system. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1018–1032, 2015
A proteomic approach to understand MMP‐3‐driven developmental processes in the postnatal cerebellum: Chaperonin CCT6A and MAP kinase as contributing factors
Authors: Van Hove Inge , Verslegers Mieke , Hu Tjing‐Tjing , Carden Martin , Arckens Lutgarde , Moons Lieve 
Published: February 2015

ABSTRACTMatrix metalloproteinase‐3 (MMP‐3) deficiency in mice was previously reported to result in a transiently retarded granule cell migration at postnatal day 8 (P8) and a sustained disturbed arborization of Purkinje cell dendrites from P8 on, concomitant with a delayed synapse formation between granule cells and Purkinje cells and resulting in mild deficits in motor performance in adult animals. However, the molecular mechanisms by which MMP‐3 contributes to proper development of the cerebellar cortex during the first postnatal weeks remains unknown. In this study, we used a functional proteomics approach to investigate alterations in protein expression in postnatal cerebella of wild‐type versus MMP‐3 deficient mice, and to further elucidate MMP‐3‐dependent pathways and downstream targets in vivo. At P8, two‐dimensional difference gel electrophoresis and mass spectrometry identified 20 unique proteins with a different expression between the two genotypes. Subsequent “Ingenuity Pathway Analysis” and Western blotting indicate that the chaperonin containing T‐complex polypeptide 1, subunit 6A and the MAP kinase signaling pathway play a key role in the MMP‐3‐dependent regulation of neurite outgrowth and neuronal migration in the developing brain. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1033–1048, 2015
Calcium signaling in neocortical development
Authors: Uhlén Per , Fritz Nicolas , Smedler Erik , Malmersjö Seth , Kanatani Shigeaki 
Published: February 2015

ABSTRACTThe calcium ion (Ca2+) is an essential second messenger that plays a pivotal role in neurogenesis. In the ventricular zone (VZ) of the neocortex, neural stem cells linger to produce progenitor cells and subsequently neurons and glial cells, which together build up the entire adult brain. The radial glial cells, with their characteristic radial fibers that stretch from the inner ventricular wall to the outer cortex, are known to be the neural stem cells of the neocortex. Migrating neurons use these radial fibers to climb from the proliferative VZ in the inner part of the brain to the outer layers of the cortex, where differentiation processes continue. To establish the complex structures that constitute the adult cerebral cortex, proliferation, migration, and differentiation must be tightly controlled by various signaling events, including cytosolic Ca2+ signaling. During development, cells regularly exhibit spontaneous Ca2+ activity that stimulates downstream effectors, which can elicit these fundamental cell processes. Spontaneous Ca2+ activity during early neocortical development depends heavily on gap junctions and voltage dependent Ca2+ channels, whereas later in development neurotransmitters and synapses exert an influence. Here, we provide an overview of the literature on Ca2+ signaling and its impact on cell proliferation, migration, and differentiation in the neocortex. We point out important historical studies and review recent progress in determining the role of Ca2+ signaling in neocortical development. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 360–368, 2015
Linking riparian woody communities and fluviomorphological characteristics in a regulated gravel‐bed river (Piave River, Northern Italy)
Authors: Picco Lorenzo , Sitzia Tommaso , Mao Luca , Comiti Francesco , Lenzi Mario A. 
Published: February 2015

AbstractGravel‐bed rivers featuring a near dynamic equilibrium state usually display a good correspondence between geomorphological and riparian community gradients, whereas long‐term human alterations may disrupt these patterns. The aim of this study was to investigate the distribution of woody riparian vegetation on three geomorphic units – floodplains, bars, and islands along the Piave River, a gravel‐bed river located in Northern Italy suffering from various degrees of human pressure and disturbances. A total of 214 plots (4 × 4 m) along three cross sections in each of two sub‐reaches of the river were surveyed in order to identify the different morphological units, dendrological characteristics of standing plants, and species composition. Three riparian woody communities, with decreasing woody species richness and tree size, were identified by cluster analysis: Alnion incanae (n = 58), Salicion eleagni (n = 52), and Rhamno‐Prunetea (n = 27). The first was significantly associated with floodplains and the others with bars. No community showed a relatively stronger association with islands. Linear mixed models showed that the three geomorphic units significantly differed in mean elevation, fine sediment depth, and geomorphic persistence, but not all Tukey contrasts were significant, and absolute differences in mean elevation above talweg were quite small (<25 cm). Moreover, the three woody communities were not always related to corresponding geomorphological gradients, which reflected the river's complex history of channel adjustments. Most notably, mean grain size did not differ between either geomorphic or vegetation units. This study therefore indicates that riparian woody vegetation along altered gravel‐bed rivers may differ substantially from those characterizing near‐equilibrium river systems. Copyright © 2015 John Wiley & Sons, Ltd.
RASAL3, a novel hematopoietic RasGAP protein, regulates the number and functions of NKT cells
Authors: Saito Suguru , Kawamura Toshihiko , Higuchi Masaya , Kobayashi Takahiro , Yoshita‐Takahashi Manami , Yamazaki Maya , Abe Manabu , Sakimura Kenji , Kanda Yasuhiro , Kawamura Hiroki , Jiang Shuying , Naito Makoto , Yoshizaki Takumi , Takahashi Masahiko , Fujii Masahiro 
Published: February 2015

Ras GTPase‐activating proteins negatively regulate the Ras/Erk signaling pathway, thereby playing crucial roles in the proliferation, function, and development of various types of cells. In this study, we identified a novel Ras GTPase‐activating proteins protein, RASAL3, which is predominantly expressed in cells of hematopoietic lineages, including NKT, B, and T cells. We established systemic RASAL3‐deficient mice, and the mice exhibited a severe decrease in NKT cells in the liver at 8 weeks of age. The treatment of RASAL3‐deficient mice with α‐GalCer, a specific agonist for NKT cells, induced liver damage, but the level was less severe than that in RASAL3‐competent mice, and the attenuated liver damage was accompanied by a reduced production of interleukin‐4 and interferon‐γ from NKT cells. RASAL3‐deficient NKT cells treated with α‐GalCer in vitro presented augmented Erk phosphorylation, suggesting that there is dysregulated Ras signaling in the NKT cells of RASAL3‐deficient mice. Taken together, these results suggest that RASAL3 plays an important role in the expansion and functions of NKT cells in the liver by negatively regulating Ras/Erk signaling, and might be a therapeutic target for NKT‐associated diseases.
Whole genome amplification induced bias in the detection of KRAS‐mutated cell populations during colorectal carcinoma tissue testing
Authors: Stranska Jana , Jancik Sylwia , Slavkovsky Rastislav , Holinkova Veronika , Rabcanova Miroslava , Vojta Petr , Hajduch Marian , Drabek Jiri 
Published: February 2015

Whole genome amplification replicates the entire DNA content of a sample and can thus help to circumvent material limitations when insufficient DNA is available for planned genetic analyses. However, there are conflicting data in the literature whether whole genome amplification introduces bias or reflects precisely the spectrum of starting DNA.We analyzed the origins of discrepancies in KRAS (Kirsten rat sarcoma viral oncogene homolog gene) mutation detection in six of ten samples amplified using the GenomePlex® Tissue Whole Genome Amplification kit 5 (WGA5; Sigma‐Aldrich, St. Louis, MO, USA) and KRAS StripAssay® (KRAS SA; ViennaLab Diagnostics, Vienna, Austria).We undertook reextraction, reamplification, retyping, authentication, reanalysis, and reinterpretation to determine whether the discrepancies originated during the preanalytical, analytical, and/or interpretative phase of genotyping.We conclude that a combination of glass slide/sample heterogeneity and biased amplification due to stochastic effects in the early phases of whole genome amplification (WGA) may have adversely affected the results obtained. Our findings are relevant for both forensic genetics testing and massively parallel sequencing using preamplification.