bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping Receptor Density on Live Cells by Using Fluorescence Correlation Spectroscopy
Authors: Chen Yan , Munteanu Alina C. , Huang Yu‐Fen , Phillips Joseph , Zhu Zhi , Mavros Michael , Tan Weihong 
Published: April 2009

AbstractSensitive surveying: Fluorescence correlation spectroscopy (FCS) was used to study receptor density and to monitor ligand–receptor interactions on live cell membranes by the introduction of fluorescently marked aptamers, which specifically bind to certain cell‐surface receptors (see schematic representation; FITC: fluorescein isothiocyanate).magnified imageStudy of the density, spatial distribution, and molecular interactions of receptors on the cell membrane provides the knowledge required to understand cellular behavior and biological functions, as well as to discover, design, and screen novel therapeutic agents. However, the mapping of receptor distribution and the monitoring of ligand–receptor interactions on live cells in a spatially and temporally ordered manner are challenging tasks. In this paper, we apply fluorescence correlation spectroscopy (FCS) to map receptor densities on live cell membranes by introducing fluorescently marked aptamer molecules, which specifically bind to certain cell‐surface receptors. The femtoliter‐sized (0.4 fL) observation volume created by FCS allows fluorescent‐aptamer detection down to 2 molecules and appears to be an ideal and highly sensitive biophysical tool for studying molecular interactions on live cells. Fluorophore‐labeled aptamers were chosen for receptor recognition because of their high binding affinity and specificity. Aptamer sgc8, generated for specific cell recognition by a process called cell systematic evolution of ligands by exponential enrichment, was determined by FCS to have a binding affinity in the picomolar range (dissociation constant Kd=790±150 pM) with its target membrane receptor, human protein tyrosine kinase‐7 (PTK7), a potential cancer biomarker. We then constructed a cellular model and applied this aptamer–receptor interaction to estimate receptor densities and distributions on the cell surface. Specifically, different expression levels of PTK7 were studied by using human leukemia CCRF‐CEM cells (1300±190 receptors μm−2) and HeLa cervical cancer cells (550±90 receptors μm−2). Competition studies with excess nonlabeled aptamers and proteinase treatment studies proved the validity of the density‐estimation approach. With its intrinsic advantages of direct measurement, high sensitivity, fast analysis, and single‐cell measurement, this FCS density‐estimation approach holds potential for future applications in molecular‐interaction studies and density estimations for subcellular structures and membrane receptors.
A Novel Tripodal Ligand Containing Three Different N‐Heterocyclic Donor Functions and Its Application in Catechol Dioxygenase Mimicking
Authors: Wagner Marit , Limberg Christian , Tietz Thomas 
Published: April 2009

AbstractProminent donors: A pyridyl, an imidazolyl, and a pyrazolyl donor function are part of the novel tripodal ligand depicted, which thus combines three of the most prominent donors applied in ligands for bioinorganic chemistry within one coordination unit. To exploit its behaviour and potential, first investigations have been carried out in relation to catechol dioxygenase mimicry.magnified imageWe describe a novel chiral ligand, L, in which three different N‐donor functions are linked to a methoxymethine unit: a methylpyrazole derivative, a methylimidazole unit, and a pyridyl residue. Complexes with FeCl2, FeBr2, and FeCl3 have been synthesized and fully characterized, including with respect to their molecular structures. While in combination with FeCl3 L coordinates in a tripodal fashion, with FeX2 (X=Cl, Br) it binds only through two functions and the pyridyl unit remains dangling. For potential modelling of intradiol and extradiol catechol dioxygenase reactivity, the complexes [LFeCl2], 1, and [LFeCl3], 3, have been treated with 3,5‐di‐tert‐butylcatechol, triethylamine, and O2. Both complexes yielded similar results in such investigations, since the LFeII–catecholate complex reacts with O2 through one‐electron oxidation in the first step. Employing 3 in acetonitrile solution, intradiol cleavage occurred, although the undesired quinone was formed as the main product. If reagents were added (NaBPh4, H+) or reaction conditions were chosen (CH2Cl2 instead of CH3CN as the solvent) that made the coordination sphere at the iron centre more accessible for a third substrate donor function, an alternative reaction route, presumably involving O2 binding at the metal, became more important, which led to extradiol cleavage. In the extreme case (CH2Cl2 as the solvent and with the addition of NaBPh4), mainly the extradiol cleavage products were formed; the intradiol products were only observed as side products then and quinone formation became negligible. Protonated base functions in the second coordination sphere increased the efficiency of extradiol cleavage only slightly. The obtained results are in line with current understanding of the function of intradiol/extradiol dioxygenases.
Sr5Al5+xSi21−xN35−xO2+x:Eu2+ (x≈0)—A Novel Green Phosphor for White‐Light pcLEDs with Disordered Intergrowth Structure
Authors: Oeckler Oliver , Kechele Juliane A. , Koss Hans , Schmidt Peter J. , Schnick Wolfgang 
Published: April 2009

AbstractA novel sialon phosphor is characterized by an unusual silicate framework, built up of edge‐ and vertex‐sharing tetrahedra (orange and green). Owing to pronounced pseudotranslations, the compound is highly disordered. It was investigated in detail by X‐ray diffraction and electron microscopy. Despite the disorder, all Sr atoms (yellow spheres) exhibit very similar coordination spheres, and doping with Eu2+ results in efficient green luminescence (see inset; Em.=emission, Exc.=excitation, Refl.=reflection).magnified imageSr5Al5+xSi21−xN35−xO2+x (x≈0) was obtained by high‐temperature synthesis (1600 to 1750 °C). Upon doping with Eu2+, the thermally very stable material shows an efficient broadband emission in the green spectral range (λmax≈510 nm, FWHM=69 nm) under UV to blue light excitation. The compound exhibits a complex intergrowth structure (space group Pmn21 (no. 31); a=23.614, b=7.487, c=9.059 Å; V=1601.5(6) Å3; Z=2, R1=0.067), which consists of highly condensed dreier ring layers alternating with sechser ring layers that include both vertex‐ and edge‐sharing (Si,Al)(O,N)4 tetrahedra. Both layer types exhibit pseudotranslational symmetry, which leads to a more or less pronounced disorder of the sechser ring layers. The Sr atoms are located in channel‐like voids of the silicate framework with coordination number nine. The compound has been characterized by single‐crystal and powder X‐ray diffraction, as well as high‐resolution electron microscopy and electron diffraction. The structure and chemical composition has been confirmed by 29Si solid‐state NMR spectroscopy, lattice energy calculations, and diverse elemental analyses.
The Production and Characterisation of Novel Conducting Redox‐Active Oligomeric Thin Films From Electrooxidised Indolo[3,2,1‐jk]carbazole
Authors: Wharton Stuart I. , Henry John B. , McNab Hamish , Mount Andrew R. 
Published: April 2009

AbstractNovel thin‐film materials have been produced from indolo[3,2,1‐jk]carbazole (see picture). These are conducting and redox‐active and, unusually, consist of three distinct covalently coupled luminescent dimer species, consistent with a specific radical‐cation coupling mechanism.magnified imageIndolo[3,2,1‐jk]carbazole (IC) has been synthesised on a gram scale by flash vacuum pyrolysis. In contrast to a previous suggestion, IC is planar and it is also highly fluorescent, with a solution quantum yield of 0.41. Electro‐oxidation of IC at a rotating disc electrode resulted in the passage of steady‐state currents and the reproducible formation of conducting, redox‐active films with constituent species that are also highly fluorescent. Unusually for coupled electroactive N‐heterocyclic systems, electrochemical and spectroscopic characterisation revealed the film to consist exclusively of three redox‐active (2,2′, 5,5′ and 2,5′ coupled) IC dimers with no polymeric products. Calculations showed this coupling pattern to be consistent with IC radical‐cation coupling through the accessible sites of highest unpaired electron density. The unusual combination of a high dimer second oxidation potential and a negligible dimer–dimer coupling rate explains the lack of further coupling. The identities of the dimeric species were confirmed by independent syntheses involving the Suzuki–Miyaura coupling of IC boronic acids as the key step. Electro‐oxidation of the IC system therefore offers a ready route to novel conducting, redox‐active molecular films and their redox‐active, luminescent dimer constituents.
Nanofibers from Oxazolidi‐2‐one Containing Hybrid Foldamers: What is the Right Molecular Size?
Authors: Angelici Gaetano , Falini Giuseppe , Hofmann Hans‐Jörg , Huster Daniel , Monari Magda , Tomasini Claudia 
Published: April 2009

AbstractA series of oligomers of the type Boc‐(L‐Phe‐D‐Oxd)n‐OBn (Boc=tert‐butoxycarbonyl; Oxd=4‐methyl‐5‐carboxy oxazolidin‐2‐one; Bn=benzyl) were prepared for n=2–5. The shortest oligomer, Boc‐(L‐Phe‐D‐Oxd)2‐OBn, aggregates and forms a fiber‐like material with an anti‐parallel β‐sheet structure in which the oligopeptide units are connected to each other by only one intermolecular hydrogen bond. The longer oligomers exhibit structural heterogeneity. They start to organize into secondary structures by the formation of intramolecular hydrogen bonds at the pentamer level. Microscopy and diffraction of the oligomers indicated a crystalline character for only the shorter ones.
Lanthaballs: Chiral, Structurally Layered Polycarbonate Tridecanuclear Lanthanoid Clusters
Authors: Chesman Anthony S. R. , Turner David R. , Moubaraki Boujemaa , Murray Keith S. , Deacon Glen B. , Batten Stuart R. 
Published: April 2009

AbstractNew balls please! The viability of using carbonate as the primary anion in cluster formation is demonstrated in the synthesis of ‘lanthaballs’, spherical tridecanuclear lanthanoid complexes with a novel [Ln(CO3)6] moiety in a [Ln13(CO3)14] core (see picture). The chirality of the lanthaballs is evidenced in the configuration of extended columns of π‐stacked phenanthroline ligands. The structural and magnetic properties of lanthaballs are investigated.magnified image
RhI‐Catalyzed Regio‐ and Stereospecific Carbonylation of 1‐(1‐Alkynyl)cyclopropyl Ketones: A Modular Entry to Highly Substituted 5,6‐Dihydrocyclopenta[c]furan‐4‐ones
Authors: Zhang Yanqing , Chen Zuliang , Xiao Yuanjing , Zhang Junliang 
Published: April 2009

AbstractEfficient route: A novel RhI‐catalyzed regio‐ and stereospecific carbonylation reaction of (1‐alkynyl)cyclopropyl ketones by selective activation of a carboncarbon σ bond of the cyclopropane ring was demonstrated (see scheme). This method provides a general, efficient, stereoselective route to synthesise 1,3,5‐trisubstituted and 1,3,5,6‐tetrasubstituted 5,6‐dihydrocyclopenta[c]furan‐4‐one with convertible functional groups.magnified image
Enzymatic Nanolithography of Polyaniline Nanopatterns by Using Peroxidase‐Modified Atomic Force Microscopy Tips
Authors: Luo Xiliang , Pedrosa Valber A. , Wang Joseph 
Published: April 2009

AbstractA new enzyme nanolithography strategy for creating conducting polymer nanostructures through the modification of AFM tips with peroxidase is described. Scanning of the modified tip in the presence of aniline and hydrogen peroxide is used for biocatalytic patterning of different polyaniline nanostructures (see figure).magnified image
Macrocyclic Disulfides for Studies of Sensitized Photolysis of the SS Bond
Authors: Huang Zhen , Yang Qing‐Zheng , Kucharski Timothy J. , Khvostichenko Daria , Wakeman Steven M. , Boulatov Roman 
Published: April 2009

AbstractSensitized photolysis: We describe a series of macrocyclic disulfides containing stiff stilbene (see scheme) as the intramolecular photosensitizer designed for fundamental mechanistic studies of sensitized photolysis of the SS bond. Preliminary studies revealed weak temperature dependence of the quantum yields, which decreased exponentially with Boltzmann‐weighted average separation between the SS bond and stiff stilbene.magnified image
“Click” Methodology for Synthesis of Functionalized [3]Catenanes: Toward Higher Interlocked Structures
Authors: Megiatto Jackson D. , Schuster David I. 
Published: April 2009

Abstract“Double Click” and it's locked: Copper(I)‐templated synthesis in conjunction with “click” chemistry has been applied in a straightforward manner for the preparation of functionalized [3]catenanes. This methodology allows the construction of higher interlocked architectures, including polymers and networks as well as electron donor–acceptor nanomaterials suitable for investigation of long‐range photoinduced electron‐transfer processes.magnified image
ChemInform Abstract: Divergent Electronic Structures of Isoelectronic Metalloclusters: Tungsten(II) Halides and Rhenium(III) Chalcogenide Halides
Authors: Gray Thomas G. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: On the Crystal Structure of the Mn—Ni—Si G‐Phase.
Authors: Yan Xinlin , Grytsiv A. , Rogl P. , Pomjakushin V. , Xue Xiangxin 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Structure and Magnetic Properties of High‐Oxygen Pressure Annealed Sr1‐xLaxCo0.5Fe0.5 O3‐δ (0 ≤ x ≤ 0.5).
Authors: Swierczek Konrad , Dabrowski Bogdan , Suescun Leopoldo , Kolesnik Stanislaw 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Growth of a Series of Lithium Garnets Ln3Li5Ta2O12 (Ln: La, Pr, Nd): Structural Properties, Alexandrite Effect and Unusual Ionic Conductivity.
Authors: Roof Irina P. , Smith Mark D. , Cussen Edmund J. , zur Loye Hans‐Conrad 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Structural and Physical Properties of 1:2 B‐Site‐Ordered Perovskite Ba3CaIr2O9.
Authors: Zhao J. G. , Yang L. X. , Yu Y. , Li F. Y. , Yu R. C. , Jin C. Q. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis, Crystal Structure and Magnetic Properties of the Sr2Al0.78Mn1.22O5.2 Anion‐Deficient Layered Perovskite.
Authors: D'Hondt Hans , et al. et al. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Metallic Re—Re Bond Formation in Different MRe2O6 (M: Fe, Co, Ni) Rutile‐Like Polymorphs: The Role of Temperature in High‐Pressure Synthesis.
Authors: Mikhailova D. , Ehrenberg H. , Oswald S. , Trots D. , Brey G. , Fuess H. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Structure of Potassium Samarium Octacyanomolybdate(IV) Decahydrate.
Authors: Typilo I. , Sereda O. , Semenyshyn D. , Stoeckli‐Evans H. , Gladyshevskii R. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal, Electronic Structures and Photoluminescence Properties of Rare‐Earth Doped LiSi2N3.
Authors: Li Y. Q. , Hirosaki N. , Xie R. J. , Takeka T. , Mitomo M. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetic Properties of KNaMSi4O10 Compounds (M: Mn, Fe, Cu).
Authors: Brandao P. , Rocha J. , Reis M. S. , dos Santos A. M. , Jin R. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Anion Substitution Route to Low Loss Colossal Dielectric CaCu3Ti4O12.
Authors: Smith Andrew E. , Calvarese T. G. , Sleight A. W. , Subramanian M. A. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ionic High‐Pressure Form of Elemental Boron.
Authors: Oganov Artem R. , Chen Jiuhua , Gatti Carlo , Ma Yanzhang , Ma Yanming , Glass Colin W. , Liu Zhenxian , Yu Tony , Kurakevych Oleksandr O. , Solozhenko Vladimir L. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: High‐Pressure Transitions in MgAl2O4 and a New High‐Pressure Phase of Mg2Al2O5.
Authors: Enomoto A. , Kojitani H. , Akaogi M. , Miura H. , Yusa H. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Na6ZnSn2, Na4.24K1.76(1)ZnSn2, and Na20Zn8Sn11: Three Intermetallic Structures Containing the Linear {Sn—Zn—Sn}6‐ Unit.
Authors: Kim Sung‐Jin , Kraus Florian , Faessler Thomas F. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Benzophenone‐Derived Catalyst with Self‐Adaptation: Highly Enantioselective Hydrogenation Irrespective of Ketone Substrates.
Authors: Wakabayashi Kazuki , Aikawa Kohsuke , Mikami Koichi 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Investigations on the Reactions of Thioamides and Related 1,3‐Diazabuta‐1,3‐dienes with Dimethyl Acetylenedicarboxylate: Synthesis of Novel Functionalized Heterocycles.
Authors: Marwaha Alka , Sudan Vishal , Mahajan Mohinder P. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Gold‐Catalyzed Deoxygenative Nazarov Cyclization of 2,4‐Dien‐1‐als for Stereoselective Synthesis of Highly Substituted Cyclopentenes.
Authors: Lin Chung‐Chang , Teng Tse‐Min , Tsai Chung‐Chih , Liao Hsin‐Yi , Liu Rai‐Shung 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Eco‐Friendly Olefin Dihydroxylation Catalyzed by Diphenyl Diselenide.
Authors: Santoro Stefano , Santi Claudio , Sabatini Michela , Testaferri Lorenzo , Tiecco Marcello 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Convergent and Stereoselective Synthesis of Trisubstituted (E)‐Alkenyl Bromides and Iodides via β‐Oxido Phosphonium Ylides.
Authors: Hodgson David M. , Arif Tanzeel 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Trihaloisocyanuric Acids as Convenient Reagents for Regioselective Halogenation of β‐Dicarbonyl Compounds.
Authors: Mendonca Gabriela F. , Sindra Haryadylla C. , de Almeida Leonardo S. , Esteves Pierre M. , de Mattos Marcio C. S. 
Published: April 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.