bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proximitäts‐vermittelte kovalente Stabilisierung niedrig‐affiner Proteinkomplexe in vitro und in vivo
Authors: Cigler Marko , Müller Thorsten G. , Horn‐Ghetko Daniel , von Wrisberg Marie‐Kristin , Fottner Maximilian , Goody Roger S. , Itzen Aymelt , Müller Matthias P. , Lang Kathrin 
Published: September 2017

AbstractDie Charakterisierung von Proteinkomplexen geringer Affinität ist wegen ihrer Dynamik sehr anspruchsvoll. Hier wird eine Methode vorgestellt, um transiente Proteinkomplexe in lebenden Zellen mit einer kovalenten, aber konformativ flexiblen Brücke zwischen den Wechselwirkungspartnern zu stabilisieren. Dazu wird eine hoch aktive Mutante der Pyrrolysyl‐tRNA‐Synthetase verwendet, die den Einbau nichtnatürlicher Aminosäuren mit langen Bromalkylketten (BrCnK) in Proteine ermöglicht. Erstmals wird gezeigt, dass Komplexe niedriger Affinität zwischen BrCnK‐haltigen Proteinen und deren Bindungspartnern in vivo in Bakterien sowie humanen Zellen stabilisiert werden können. Mit diesem Ansatz konnte die Kristallstruktur eines transienten, GDP‐gebundenen Komplexes zwischen einem kleinen G‐Protein und seinem GTP‐Austauschfaktor bestimmt werden. Die Methode kann als generelles Hilfsmittel zur Validierung und Charakterisierung von Protein‐Protein‐Wechselwirkungen in vitro und in vivo eingesetzt werden.
Low‐Temperature Molten‐Salt Production of Silicon Nanowires by the Electrochemical Reduction of CaSiO3
Authors: Dong Yifan , Slade Tyler , Stolt Matthew J. , Li Linsen , Girard Steven N. , Mai Liqiang , Jin Song 
Published: September 2017

AbstractSilicon is an extremely important technological material, but its current industrial production by the carbothermic reduction of SiO2 is energy intensive and generates CO2 emissions. Herein, we developed a more sustainable method to produce silicon nanowires (Si NWs) in bulk quantities through the direct electrochemical reduction of CaSiO3, an abundant and inexpensive Si source soluble in molten salts, at a low temperature of 650 °C by using low‐melting‐point ternary molten salts CaCl2–MgCl2–NaCl, which still retains high CaSiO3 solubility, and a supporting electrolyte of CaO, which facilitates the transport of O2− anions, drastically improves the reaction kinetics, and enables the electrolysis at low temperatures. The Si nanowire product can be used as high‐capacity Li‐ion battery anode materials with excellent cycling performance. This environmentally friendly strategy for the practical production of Si at lower temperatures can be applied to other molten salt systems and is also promising for waste glass and coal ash recycling.
Visible‐Light‐Initiated Manganese Catalysis for C−H Alkylation of Heteroarenes: Applications and Mechanistic Studies
Authors: Nuhant Philippe , Oderinde Martins S. , Genovino Julien , Juneau Antoine , Gagné Yohann , Allais Christophe , Chinigo Gary M. , Choi Chulho , Sach Neal W. , Bernier Louise , Fobian Yvette M. , Bundesmann Mark W. , Khunte Bhagyashree , Frenette Mathieu , Fadeyi Olugbeminiyi O. 
Published: September 2017

AbstractA visible‐light‐driven Minisci protocol that employs an inexpensive earth‐abundant metal catalyst, decacarbonyldimanganese Mn2(CO)10, to generate alkyl radicals from alkyl iodides has been developed. This Minisci protocol is compatible with a wide array of sensitive functional groups, including oxetanes, sugar moieties, azetidines, tert‐butyl carbamates (Boc‐group), cyclobutanes, and spirocycles. The robustness of this protocol is demonstrated on the late‐stage functionalization of complex nitrogen‐containing drugs. Photophysical and DFT studies indicate a light‐initiated chain reaction mechanism propagated by .Mn(CO)5. The rate‐limiting step is the iodine abstraction from an alkyl iodide by .Mn(CO)5.
Carbene Footprinting Reveals Binding Interfaces of a Multimeric Membrane‐Spanning Protein
Authors: Manzi Lucio , Barrow Andrew S. , Hopper Jonathan T. S. , Kaminska Renata , Kleanthous Colin , Robinson Carol V. , Moses John E. , Oldham Neil J. 
Published: September 2017

AbstractMapping the interaction sites between membrane‐spanning proteins is a key challenge in structural biology. In this study a carbene‐footprinting approach was developed and applied to identify the interfacial sites of a trimeric, integral membrane protein, OmpF, solubilised in micelles. The diazirine‐based footprinting probe is effectively sequestered by, and incorporated into, the micelles, thus leading to efficient labelling of the membrane‐spanning regions of the protein upon irradiation at 349 nm. Areas associated with protein–protein interactions between the trimer subunits remained unlabelled, thus revealing their location.
A Radiolabeling‐Free, qPCR‐Based Method for Locus‐Specific Pseudouridine Detection
Authors: Lei Zhixin , Yi Chengqi 
Published: September 2017

AbstractPseudouridine (Ψ) is the most abundant post‐transcriptional RNA modification. Methods have been developed for locus‐specific Ψ detection; however, they often involve radiolabeling of RNA, require advanced experimental skills, and can be time‐consuming. Herein we report a radiolabeling‐free, qPCR‐based method to rapidly detect locus‐specific Ψ. Pseudouridine residues were labeled chemically, and the resulting adducts induced mutation/deletion during reverse transcription (RT) to generate qPCR products with different melting temperatures and hence altered melting curves. We validated our method on known Ψ sites in rRNA and then used it to sensitively detect Ψ residues in lncRNA and mRNA of low abundance. Finally, we applied our method to pseudouridine synthase identification and showed that Ψ616 in PSME2 mRNA is dependent on PUS7. Our facile and cost‐effective method takes only 1.5 days to complete, and with slight adjustment it can be applied to the detection of other epitranscriptomic marks.
A Water‐Containing Organopotassium Compound Based on Bis(4,6‐tBu‐benzoxazol‐2‐yl)methanide and Its Unexpected Stability to Hydrolysis
Authors: Koehne Ingo , Bachmann Sebastian , Herbst‐Irmer Regine , Stalke Dietmar 
Published: September 2017

AbstractThe bulky bis(4,6‐tBu‐benzoxazol‐2‐yl)methane ligand system enabled the synthesis of the water‐containing organometallic potassium complex [(18‐crown‐6)K{(4,6‐tBu‐OCNC6H2)2CH}⋅H2O] (2), which is an unprecedented example of a water‐stable reactive organopotassium compound. Furthermore, 2 is a rare example of a bis(benzoxazol‐2‐yl)methanide ligand displaying solely O‐coordination to a metal ion. Compound 2 was fully characterized through its solid‐state structure. Furthermore, its behavior in solution was investigated by NMR titration DOSY experiments. These revealed full protonation of the complex only after seven days and the addition of 114 equivalents of water.
Proximity‐Triggered Covalent Stabilization of Low‐Affinity Protein Complexes In Vitro and In Vivo
Authors: Cigler Marko , Müller Thorsten G. , Horn‐Ghetko Daniel , von Wrisberg Marie‐Kristin , Fottner Maximilian , Goody Roger S. , Itzen Aymelt , Müller Matthias P. , Lang Kathrin 
Published: September 2017

AbstractThe characterization of low‐affinity protein complexes is challenging due to their dynamic nature. Here, we present a method to stabilize transient protein complexes in vivo by generating a covalent and conformationally flexible bridge between the interaction partners. A highly active pyrrolysyl tRNA synthetase mutant directs the incorporation of unnatural amino acids bearing bromoalkyl moieties (BrCnK) into proteins. We demonstrate for the first time that low‐affinity protein complexes between BrCnK‐containing proteins and their binding partners can be stabilized in vivo in bacterial and mammalian cells. Using this approach, we determined the crystal structure of a transient GDP‐bound complex between a small G‐protein and its nucleotide exchange factor. We envision that this approach will prove valuable as a general tool for validating and characterizing protein–protein interactions in vitro and in vivo.
Synthesis, characterization and biological application of cyclometalated heteroleptic platinum(II) complexes
Authors: Lunagariya Miral V. , Thakor Khyati P. , Patel Nikita J. , Patel Mohan N. 
Published: September 2017

AbstractA series of square planar cyclometalated heteroleptic platinum(II) complexes of the type [(C^N)Pt(O^O)] [where, O^O is a β‐diketonato ligand of acetylacetone (acac), C^N = cyclometalating 7‐(4‐fluorophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L1), 7‐(4‐chlorophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L2), 7‐(4‐bromophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L3), 7‐(4‐methoxyphenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L4), 5‐phenyl‐7‐(p‐tolyl)pyrazolo[1,5‐a]pyrimidine (L5)] have been design, synthesized and characterized. All compounds have been screened for biological studies like in vitro antibacterial, in vitro cytotoxicity, cellular level cytotoxicity, absorption titration, viscosity measurements, fluorescence quenching analysis, molecular docking and DNA nuclease. The intrinsic binding constants (Kb) of compounds with HS‐DNA has been obtained in range of 2.892–0.242 × 105 M−1. All the compounds bound with HS DNA by partial intercalative mode of binding. MIC study has been carried out against Gram(+ve) and Gram(−ve) bacterial species. In vitro cytotoxicity against brine shrimp lethality bioassay has been also carried out. The LC50 values of the ligands and complexes have been found in range of 56.49–120.22 μg/mL and 6.71–11.96 μg/mL, respectively.
Selective fluorescence quenching of papain–Au nanoclusters by self‐polymerization of dopamine
Authors: Peng Jun , Han Cai‐Ling , Ling Jian , Liu Chao‐Juan , Ding Zhong‐Tao , Cao Qiu‐E 
Published: September 2017

AbstractIn this paper, we synthesized a papain‐stabilized fluorescent Au nanocluster (NC) probe and studied its interaction with dopamine. As fluorescence of papain–Au NCs is quenched in the presence of dopamine under alkaline conditions, we were able to establish a simple, selective analytical method for dopamine determination. By studying the fluorescence lifetime and dynamic light scattering of the NCs before and after interaction with dopamine, we found that this fluorescence quenching mechanism was possibly due to dopamine self‐polymerization that produced polydopamine that cross‐linked papain–Au NCs. Based on this new phenomenon, we proposed a highly selective analytical method for dopamine detection. Other small organic molecules, such as amino acids, ascorbic acid and uric acid did not interfere with dopamine detection. Dopamine in the range 20–100 μM can be linearly detected by the fluorescence quenching ratio of gold nanoclusters. Dopamine detection could be visually realized by watching color changes of papain–Au NCs under UV light or daylight, as both fluorescence and absorption of the papain–Au NCs changed during dopamine polymerization.
Enacting collective support for the European integration: Participation in pro‐integration action and preference for specific transnational acculturation strategies
Authors: Bliuc Ana‐Maria , McGarty Craig , Badea Constantina , Boza Mihaela 
Published: September 2017

AbstractWe propose that collective support for European integration is mani‐fested in 2 distinct forms: first, as engagement in socio‐political action by citizens who seek to change their nation and its status in Europe. Second, it is manifested as a transnational acculturation process that impacts on both nations and their citizens. These processes potentially engage social identities at 3 levels: national, European and as supporters of the European integration. Here, we examine these different levels of identification as part of a model predicting collective support for the European integration. To capture the dimension of transnationality, we collected data from 2 Romanian samples, 1 of participants living in their country of origin (N = 203), and 1 of participants living as migrants outside Romania (N = 196). We found that identification as a pro‐integration supporter flows from European and Romanian national identifications and is an excellent predictor of collective support for European integration in both its forms. We conclude by discussing how our findings can be applied to the design of intervention strategies and policies to promote support for the European Union and the integration process in the current socio‐political climate (where the unity and the very existence of European Union are under threat).
Insight into the Synergism between Copper Species and Surface Defects Influenced by Copper Content over Copper/Ceria Catalysts for the Hydrogenation of Carbonate
Authors: Li Huabo , Cui Yuanyuan , Liu Qianqian , Dai Wei‐Lin 
Published: September 2017

AbstractVarious Cu/CeO2 nanorod catalysts with different copper contents were synthesized through a facile coprecipitation method for the hydrogenation of diethyl carbonate to methanol in a fixed‐bed reactor. The methanol yield increased upon increasing the copper loading, but large excess amounts of copper led to deactivation of the catalyst at a high liquid hourly space velocity because of aggregation of the active metal. The 20Cu/CeO2 and 30Cu/CeO2 catalysts displayed superior catalytic performance with methanol space‐time yields of 8.4 and 8.1 mmol gcat−1 h−1, respectively. The remarkably enhanced catalytic performance was mainly ascribed to a high Cu0 surface area, appropriate ratio of Cu+/Cu0, and more surface oxygen vacancies associated with Ce3+, which stemmed from a strong interaction between Cu and the CeO2 support.
Boosting the Specific Surface Area of Hierarchical Porous Carbon Aerogel through the Multiple Roles of the Catalyst for High‐Performance Supercapacitors
Authors: Li Feng , Xie Lijing , Sun Guohua , Su Fangyuan , Kong Qingqiang , Li Qian , Chao Yuguang , Guo Xiangyun , Chen Chengmeng 
Published: September 2017

AbstractRational design of carbon aerogel with high specific surface area and controllable porosity is in great need for advanced energy storage systems. Herein, a hierarchical porous carbon aerogel has been successfully prepared through the polymerization of resorcinol and formaldehyde in the presence of K2CO3 and a subsequent one‐step carbonization process. In this design, three functionalities of K2CO3 are involved, namely, as a catalyst effectively promoting the cross‐linking of resorcinol and formaldehyde, as a shape‐directing agent regulating the resulting carbon network, and as an in situ activator constructing the interconnected hierarchical porous skeleton within the carbonization process. Impressively, an ultrahigh specific surface area of 4568.9 m2 g−1 and a miraculous pore volume of 4.92 cm3 g−1 is achieved for the carbon aerogel with a mass ratio of K2CO3/resorcinol up to 3. Benefiting from its structural merits, the assembled coin‐type supercapacitor with an as‐obtained carbon aerogel electrode in 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF4) electrolyte delivers an excellent energy density of 78.1 Wh kg−1 at a power density of 2.7 kW kg−1, as well as a favorable rate capability of 88 % after 8000 cycles. Such a design strategy opens up a new opportunity for further development of hierarchically porous carbon aerogels applied in the fields of adsorption, catalysis, and energy storage devices.
To correlate and predict the potential and new functions of traditional Chinese medicine formulas based on similarity indices
Authors: Xu Lu , Gao Peng‐Fei , Qin Guo‐Chan , An Ying‐He , Tang Bang‐Cheng , Wang Huan , She Yuan‐Bin 
Published: September 2017

AbstractA typical traditional Chinese medicine (TCM) formula (or a prescription) is composed of 1 or several single herbs. The number of possible TCM formulas is nearly as large as that of chemical structures, so the development of quantitative formula‐activity relationship models is as appealing as to build a quantitative structure‐activity relationship model. In this work, a formula descriptor system based on the TCM holistic medical model is generated to correlate and predict formula functions by using similarity indices. First, 73 general descriptors of 78 formulas from Chinese Pharmacopeia (2010) are computed. Second, 6 different similarity indices are used to evaluate the similarities among the 78 formulas. As the main functions of the 78 formulas are known and annotated, a significant similarity implies that a formula is likely to have some new functions owned by its “analogue.” Finally, different similarity measures are compared with reference to the results of experimental and clinical studies. The consistency between some predictions and the literature results indicates that the proposed method can provide clues for mining and investigating the unknown functions of TCM formulas.
Abnormal Tin–Boron Exchange in the Attempted Synthesis of a Borylated Borole
Authors: Braunschweig Holger , Dömling Michael , Kachel Stephanie , Kelch Hauke , Kramer Thomas , Krummenacher Ivo , Lenczyk Carsten , Lin Shujuan , Lin Zhenyang , Possiel Christian , Radacki Krzysztof 
Published: September 2017

AbstractBoroles are important motifs within functional materials. With the aim to prepare a pinacolboryl‐substituted derivative, the metallacycle transfer from corresponding zirconium and tin precursors has been explored. We show that the reaction of 1,1‐dimethyl‐2,3,4,5‐tetrapinacolborylstannole with dichloro(phenyl)borane does not provide the desired borole, but instead a stannyl‐substituted 1‐chloroboracyclopent‐3‐ene. Spectroscopic and structural details of this highly functionalized boracycle indicate that intramolecular interactions between the tin and oxygen atoms of the boryl substituents may account for the unexpected outcome of the tin‐boron exchange reaction.
One‐Step Assembly of Visible and Near‐Infrared Emitting Metallacrown Dimers Using a Bifunctional Linker
Authors: Nguyen Tu N. , Chow Chun Y. , Eliseeva Svetlana V. , Trivedi Evan R. , Kampf Jeff W. , Martinić Ivana , Petoud Stéphane , Pecoraro Vincent L. 
Published: September 2017

AbstractA family of dimeric LnIII[12‐MCGa(III)N(shi)‐4] metallacrowns (MCs) (LnIII=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) was synthesized using the isophthalate group (ip2−) as a linker. The [LnGa4]2 complexes exhibit remarkable photophysical properties, with large molar absorptivities of ≈4×104 m−1 cm−1, high quantum yields and long luminescence lifetimes with values of (i) 31.2(2)% and 1.410(1) ms, respectively for the visible‐emitting [TbGa4]2 complex and (ii) 2.43(6)% and 30.5(1) μs for the near‐infrared (NIR) emitting [YbGa4]2 in the solid state. The NIR emission was obtained not only from Yb, Nd, and Er complexes but also from the less frequently observed emitters such as Pr and Ho. In addition, emission in both visible and NIR domains could be detected for Dy and Sm MCs. ESI‐MS and UV/Vis data revealed that the complexes are highly stable in dimethylsulfoxide (DMSO) solution with the 1H‐ and COSY‐NMR spectra of the diamagnetic [YGa4]2 analogue providing evidence for long‐term solution stability. This new approach allows one to construct a basis for highly luminescent MCs that may be further modified to be adapted for applications such as optical imaging.
Exploiting the σ‐Hole Concept: An Infrared and Raman‐Based Characterization of the S⋅⋅⋅O Chalcogen Bond between 2,2,4,4‐Tetrafluoro‐1,3‐dithiethane and Dimethyl Ether
Authors: Geboes Yannick , De Vleeschouwer Freija , De Proft Frank , Herrebout Wouter A. 
Published: September 2017

AbstractIn the last decade, halogen bonds, noncovalent interactions formed between positive regions in the electrostatic potential on halogen atoms, often referred to as σ‐holes, and electron‐rich sites, have gained a lot of interest. Recently, this interest has been expanded towards interactions with Group V and Group VI elements, giving rise to pnicogen and chalcogen bonds. Although chalcogen bonds have already shown some promising results for applications in crystallography and catalysis, experimental results characterising these noncovalent interactions remain scarce. In this combined experimental and theoretical study, original data allowing the characterization of S⋅⋅⋅O chalcogen bonds is obtained by studying the 1:1 molecular complexes between 2,2,4,4‐tetrafluoro‐1,3‐dithiethane (C2F4S2) and dimethyl ether (DME). Ab initio calculations of the C2F4S2⋅DME dimer yield two stable chalcogen‐bonded isomers, the difference being the presence or absence of secondary F⋅⋅⋅H interactions. Liquid‐krypton solutions containing C2F4S2 and DME were studied using FTIR and Raman spectroscopy. Upon subtraction of rescaled monomer spectra, clear complex bands are observed. The observed complexation shifts agree favourably with the ab initio calculated shifts of the chalcogen‐bonded complexes. The 1:1 stoichiometry of the complex is confirmed and a complexation enthalpy of −13.5(1) kJ mol−1 is found, which is in good agreement with the calculated values. A Ziegler–Rauk energy decomposition analysis revealed that electrostatic interactions prominently dominate over orbital interactions. Nevertheless, significant charge transfer occurs from the oxygen in DME to one of the sulfur atoms in C2F4S2 and the carbon along the extension of the chalcogen bond.
Dinitromethyl‐3(5)‐1,2,4‐oxadiazole Derivatives from Controllable Cyclization Strategies
Authors: Tang Yongxing , He Chunlin , Imler Gregory H. , Parrish Damon A. , Shreeve Jean'ne M. 
Published: September 2017

AbstractN‐Cyanoimidate (1) with hydroxylamine hydrochloride in the presence of triethylamine gives different products (2 a or 2 b) as a function of the sequence of reactant addition. Further oxidation/nitration/decarboxylation/acidification reactions of 2 a/2 b generate dinitromethyl‐3(5)‐1,2,4‐oxadiazole derivatives, including a surprising energetic compound with high oxygen balance, 3‐(dinitromethyl)‐1,2,4‐oxadiazol‐5‐one (5) as well as 5,5′‐dinitromethyl‐3,3′‐azo‐1,2,4‐oxadiazole (9). Some salts of 5 and 9 as precursors were also prepared. All were fully characterized using multinuclear NMR and IR spectroscopy, and elemental analyses as well as low‐temperature single‐crystal X‐ray diffraction for 4, 5, 7 and 8. In addition, their properties (thermal stability, detonation performance and sensitivity to impact and friction) were investigated. Among them, 5 and 8 show promising detonation performance as energetic materials.
Preorganized AgI Bimetallic Precursor with Labile Diphosphorus Ligands for a Programmed Synthesis of Organometallic–Organic Hybrid Polymers
Authors: Moussa Mehdi Elsayed , Seidl Michael , Balázs Gábor , Zabel Manfred , Virovets Alexander V. , Attenberger Bianca , Schreiner Andrea , Scheer Manfred 
Published: September 2017

AbstractAn AgI dimer capped with labile organometallic diphosphorus ligands [Cp2Mo2(CO)4(η2‐P2)] (Cp=C5H5) acts as a highly pre‐organized molecular precursor to direct the construction of 1D or 2D, and 3D organometallic–organic hybrid coordination polymers upon reaction with ditopic pyridine‐based linkers. The formation of the supramolecular aggregates can be controlled by the stoichiometry of the organic molecules, and the mechanism is supported by DFT calculations.