bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hidden Conformations in Aspergillus niger Monoamine Oxidase are Key for Catalytic Efficiency
Authors: Curado‐Carballada Christian , Feixas Ferran , Iglesias‐Fernández Javier , Osuna Sílvia 
Published: January 2019

AbstractEnzymes exist as an ensemble of conformational states, whose populations can be shifted by substrate binding, allosteric interactions, but also by introducing mutations to their sequence. Tuning the populations of the enzyme conformational states through mutation enables evolution towards novel activity. Herein, Markov state models are used to unveil hidden conformational states of monoamine oxidase from Aspergillus niger (MAO‐N). These hidden conformations, not previously observed by any other technique, play a crucial role in substrate binding and enzyme activity. This reveals how distal mutations regulate MAO‐N activity by stabilizing these hidden, catalytically important conformational states, but also by modulating the communication pathway between both MAO‐N subunits.
A Guiding Principle for Strengthening Crosslinked Polymers: Synthesis and Application of Mobility‐Controlling Rotaxane Crosslinkers
Authors: Sawada Jun , Aoki Daisuke , Otsuka Hideyuki , Takata Toshikazu 
Published: January 2019

AbstractThree component mobility controlling vinylic rotaxane crosslinkers with two radically polymerizable vinyl groups (RC_Rs) were synthesized to prove that the mobility of the components of the RC_Rs plays a crucial role in determining the properties of rotaxane‐crosslinked polymers (RCPs). RC_Rs (R=H, Me, or Et) were obtained from living ring‐opening polymerization. RCP_Et was prepared using RC_Et, which exhibits the lowest component mobility. The low component mobility is reflected in inferior mechanical strength and stretching ability in tensile stress tests compared to components with good (R=Me) and high (R=H) mobility. However, RCP_Et exhibited significantly higher stress and strain values than the corresponding covalently crosslinked polymers (CCP_Rs). These results indicate that a suitable component mobility substantially enhances the mechanical strength of RCPs. This behavior could serve as a guiding principle for the molecular design of advanced RCs.
Vergleichende Acetonadsorption an Wasser‐ und Eisoberflächen
Authors: Cyran Jenée D. , Backus Ellen H. G. , van Zadel Marc‐Jan , Bonn Mischa 
Published: January 2019

AbstractKleine organische Moleküle auf Eis‐ und Wasseroberflächen sind allgegenwärtig in der Natur und beeinflussen diverse Umweltprozesse essentiell. Hier kombinieren wir oberflächenspezifische Summenfrequenzspektroskopie mit einer regelbaren Durchflusszelle um die molekulare Adsorption von Aceton an die Basisfläche von monokristallinem Ih‐Eis mit einer großen Oberfläche zu untersuchen. Durch den direkten Vergleich der Acetonadsorption an der Eis/Luft‐ und Wasser/Luft‐Grenzfläche können wir zwei verschiedene Adsorptionsverhalten identifizieren, die sich durch unterschiedliche Signale der freien OH‐Gruppe und des Wasserstoffbrückennetzwerks für Eis und Wasser zeigen. Die Adsorption an Eis geschieht vorzugsweise durch die Interaktion mit der freien OH‐Gruppe, während die Interaktion von Aceton mit der Oberfläche von Wasser weniger spezifisch erscheint.
Stereospecific Synthesis of α‐Hydroxy‐Cyclopropylboronates from Allylic Epoxides
Authors: Amenós Laura , Trulli Laura , Nóvoa Luis , Parra Alejandro , Tortosa Mariola 
Published: January 2019

AbstractHerein, we report a catalytic and stereospecific method for the preparation of enantioenriched α‐hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively prepared. Functionalization of the carbon–boron bond provides access to different enantiomerically enriched trisubstituted cyclopropanes from a common intermediate.
Extrinsic Heavy Metal Atom Effect on the Solid‐State Room Temperature Phosphorescence of Cyclic Triimidazole
Authors: Cariati Elena , Forni Alessandra , Lucenti Elena , Marinotto Daniele , Previtali Andrea , Righetto Stefania , Botta Chiara , Bold Victor , Kravtsov Victor , Fonari Marina S. 
Published: January 2019

AbstractFour coordination compounds [Zn3(CH3COO)6(H2O)2](TT)2 [Cd(H2O)6](ClO4)2(TT)2, [Cd(H2O)6](BF4)2(TT)2, [Zn(H2O)6](BF4)2(TT)2 (1–4) accommodating the crystallization induced emissive triimidazo[1,2‐a:1′,2′‐c:1′′,2′′‐e][1,3,5]triazine (TT) as a guest in their crystal lattice are isolated and fully photophysically and structurally characterized. Their emission properties are compared with those of afterglow TT and interpreted taking into account the heavy atom effect and crystal packing similarities and differences. In the case of 1, due to the closeness of the TT H‐aggregates arrangement with that of the phosphor's pure phase, the observed intensification of the phosphorescent emission at the expense of the prompt one is attributed to the extrinsic heavy atom effect of Zn. In 2 and 3, the heavier Cd atom is responsible for a decrease in the lifetimes of the afterglow emission, despite the presence of tightly overlapped H‐dimers in the crystal structure. Finally, for 4, isostructural with 3, the Zn atom reveals in RTUP lifetime comparable with that of 1.
Controlling the Emergence and Shift Direction of Mechanochromic Luminescence Color of a Pyridine‐Terminated Compound
Authors: Kondo Mizuho , Yamoto Taku , Miura Seiya , Hashimoto Mayuko , Kitamura Chitoshi , Kawatsuki Nobuhiro 
Published: January 2019

AbstractIn this study, mechanochromic luminescence was induced in a complex of mechano‐inactive compounds. Dye/acid complexes containing the same π‐conjugated backbones were prepared. While the luminophore showed blue and red shifts in photoluminescence spectra when combined with different acids by grinding, it exhibited slight mechanoresponsiveness itself. Also, compounds with similar molecular backbones to the dye/acid complex were synthesized to clarify the color change mechanism. The compounds showed both blue and red shifts in photoluminescence and diffuse reflectance spectra upon grinding, indicating that mechanochromic luminescence in the hydrogen‐bonded complex is like its monomeric analogue and that aggregation structure plays an important role in mechanoresponsive behavior rather than the π‐conjugated structure. It was shown that a color change can be mechanically induced by imitating the solid‐state aggregation structure of other mechanoresponsive compounds without synthetic modification.
Design of a Quinoidal Thieno[3,4‐b]thiophene‐Diketopyrrolopyrrole‐Based Small Molecule as n‐Type Semiconductor
Authors: Ren Longbin , Yuan Dafei , Zhu Xiaozhang 
Published: January 2019

AbstractA quinoidal small‐molecule semiconductor QDPPBTT was synthesized. Organic thin‐film transistor (OTFT) devices based on QDPPBTT showed an electron mobility as high as 0.13 cm2 V−1 s−1 and Ion/Ioff ratio of 106 under ambient conditions. We suggested that 2D extended π‐conjugation and quinoid‐enhancing effect had an important role in electron mobility and stability of n‐type FET devices, which might be a good strategy in designing new material systems.
Nano‐Graphene Oxide Based Multichannel Sensor Arrays towards Sensing of Protein Mixtures
Authors: Behera Pradipta , De Mrinmoy 
Published: January 2019

AbstractOptical array‐based sensors are attractive candidates for the detection of various bio‐analytes due to their convenient fabrication and measurements. For array‐based sensors, multichannel arrays are more advantageous and used frequently in many electronic sensors. But most reported optically array based sensors are constructed on a single channel array. This difficulty is mainly instigated from the overlap in optical responses. In this report we have used nano‐graphene oxide (nGO) and suitable fluorophores as sensor elements to construct a multichannel sensor array for the detection of protein analytes. By using the optimized multichannel array we are able to detect different proteins and mixtures of proteins with 100 % classification accuracy at sub‐nanomolar concentration. This modified method expedites the sensing analysis as well as minimizes the use of both analyte and sensor elements in array‐based protein sensing. We have also used this system for the single channel array‐based sensing to compare the sensitivity and the efficacy of these two systems for other applications. This work demonstrated an intrinsic trade‐off associated with these two methods which may be necessary to balance for array‐based analyte detections.
The hierarchical metaregression approach and learning from clinical evidence
Authors: Verde Pablo Emilio 
Published: January 2019

AbstractThe hierarchical metaregression (HMR) approach is a multiparameter Bayesian approach for meta‐analysis, which generalizes the standard mixed effects models by explicitly modeling the data collection process in the meta‐analysis. The HMR allows to investigate the potential external validity of experimental results as well as to assess the internal validity of the studies included in a systematic review. The HMR automatically identifies studies presenting conflicting evidence and it downweights their influence in the meta‐analysis. In addition, the HMR allows to perform cross‐evidence synthesis, which combines aggregated results from randomized controlled trials to predict effectiveness in a single‐arm observational study with individual participant data (IPD). In this paper, we evaluate the HMR approach using simulated data examples. We present a new real case study in diabetes research, along with a new R package called jarbes (just a rather Bayesian evidence synthesis), which automatizes the complex computations involved in the HMR.
Essential Oil Composition of Different Plant Parts from CroatianPetasites albus(L.) Gaertn.andPetasites hybridus(L.) G.Gaertn., B.Mey. & Scherb.(Asteraceae)
Authors: Friščić Maja , Jerković Igor , Marijanović Zvonimir , Dragović Sanja , Hazler Pilepić Kroata , Maleš Željan 
Published: January 2019

AbstractEssential oil compositions of fresh leaves, flower stems and rhizomes obtained by hydrodistillation from different Croatian populations ofPetasites albus(L.) Gaertn.andPetasites hybridus(L.) G.Gaertn., B.Mey. & Scherb.(four of each species) were investigated using gas chromatography‐flame ionization detection and gas chromatography‐mass spectrometry. Altogether, 118 constituents were identified, accounting for 81.19–96.81 % of total oil composition. All essential oils were characterized by oxygenated sesquiterpenes, with distinct compounds recorded for both investigated species. Clear separation between the two species was confirmed by principal component analysis and hierarchical cluster analysis. This is the first study that recorded intraspecific variations of essential oil constituents fromP. albusandP. hybridus. Obtained results could contribute to the understanding of their medicinal and nutritional value.
Differently Tagged Probes for Protein Profiling of Mitochondria
Authors: Dong Jia , Hong Danqi , Lang Wenjie , Huang Jintao , Qian Linghui , Zhu Qing , Li Lin , Ge Jingyan 
Published: January 2019

AbstractThe mitochondrion is one of the most important organelles in the eukaryotic cell. Characterization of the mitochondrial proteome is a prerequisite for understanding its cellular functions at the molecular level. Here we report a proteomics method based on mitochondrion‐targeting groups and click chemistry. In our strategy, three different mitochondrion‐targeting moieties were each augmented with a clickable handle and a cysteine‐reactive group. Fluorescence‐based bioimaging and fractionation experiments clearly showed that most signals arising from the labels were localized in the mitochondria of cells, as a result of covalent attachment between probe and target proteins. The three probes had distinct profiling characteristics. Furthermore, we successfully identified more than two hundred mitochondrial proteins. The results showed that different mitochondrion‐targeting groups targeted distinct proteins with partial overlap. Most of the labeled proteins were localized in the mitochondrial matrix and inner mitochondrial membrane. Our results provide a tool for chemoproteomic analysis of mitochondrion‐related proteins.
Charge Transfer Reactions in CO2 Electroreduction on Manganese Doped Ceria
Authors: Huang Zhidong , Shang Lei , Qi Huiying , Zhao Zhe , Tu Baofeng , Yang Weishen , Cheng Mojie 
Published: January 2019

AbstractThe key to electrochemical conversion of carbon dioxide (CO2) into fuels lies in effient charge transfer reactions. Here, we depict from the polarzation resistance analysis that the electroreduction of CO2 to CO on manganese doped ceria (CMO) passes through two elementary charge transfer reactions. One reaction is asscociated with
to
and another associated with
to CO. As the rate determing step, the first one has an apparenent acitvation energy of 178.7 kJ mol−1 and a pressure dependence of
. The second one has an apparent acitvation energy of 100.6 kJ mol−1 and a pressure dependence of
. Based on the experimental results, we give the kenetic expression for the CO2 electroreduction rate on CMO.
Electromigration in Lithium Whisker Formation Plays Insignificant Role during Electroplating
Authors: Rulev Alexey A. , Sergeev Artem V. , Yashina Lada V. , Jacob Timo , Itkis Daniil M. 
Published: January 2019

AbstractPlating of metallic Li results in deposition of needle‐like structures, whose prevention is a fundamental challenge that currently restricts the development and application of high energy Li‐metal rechargeable batteries. Over the last decades, a number of mechanisms were proposed to explain morphological instabilities of planar crystallization fronts. The suggested reasons for non‐uniform deposition include Li+ concentration gradients in the nutrient phase, accelerated electromigration to the tip of the growing needle, specific nucleation behavior, mechanical properties of the solid‐electrolyte interphase, and many more. Here, we unravel the role of electromigration currents by adding indifferent cations (TBA+, TEA+) to screen for non‐uniform electric fields, thus, suppressing migration‐driven mass‐transfer. Nearly full exclusion of electromigration currents showed no impact on the morphology of electrodeposited lithium. Therefore, the role of electromigration seems negligible, and electric field edge effects are undoubtedly not the main driving force for filament growth during Li plating.
Diketopyrrolopyrrole Bis‐Phosphonate Conjugate: A New Fluorescent Probe for In Vitro Bone Imaging
Authors: Chiminazzo Andrea , Borsato Giuseppe , Favero Alessia , Fabbro Chiara , McKenna Charles E. , Dalle Carbonare Luca Giuseppe , Valenti Maria Teresa , Fabris Fabrizio , Scarso Alessandro 
Published: January 2019

AbstractThe synthesis of a conjugate molecule between an unusual red‐fluorescent diketopyrrolopyrrole (DPP) unit and a bis‐phosphonate (BP) precursor by a click‐chemistry strategy to target bone tissue and monitor the interaction is reported. After thorough investigation, conjugation through a triazole unit between a γ‐azido rather than a β‐azido BP and an alkyne‐functionalized DPP fluorophore group turned out to be the winning strategy. Visualization of the DPP‐BP conjugate on osteoclasts and specific antiresorption activity were successfully demonstrated.
Carboranyl Analogues of Celecoxib with Potent Cytostatic Activity against Human Melanoma and Colon Cancer Cell Lines
Authors: Buzharevski Antonio , Paskas Svetlana , Sárosi Menyhárt‐Botond , Laube Markus , Lönnecke Peter , Neumann Wilma , Mijatovic Sanja , Maksimovic‐Ivanic Danijela , Pietzsch Jens , Hey‐Hawkins Evamarie 
Published: January 2019

AbstractNonsteroidal anti‐inflammatory drugs (NSAIDs) are the most common way of treating inflammatory disorders. Their widespread use helped reveal their other modes of action as pharmaceuticals, such as a profound effect on various cancers. Celecoxib has proven to be a very prominent member of this group with cytostatic activities. On the other hand, the highly dynamic field of drug design is constantly searching for new ways of modifying known structures to obtain more powerful and less harmful drugs. A very interesting development is the implementation of carboranes in pharmacologically active structures, mostly as phenyl mimetics. Herein we report the synthesis of three carborane‐containing derivatives of the COX‐2‐selective NSAID celecoxib. The new compounds proved to have promising cytostatic potential against various melanoma and colorectal adenocarcinoma cell lines. Inhibited proliferation accompanied by caspase‐independent apoptotic cell death was found to be the main cause of decreased cell viability upon treatment with the most efficient celecoxib analogue, 3 b (4‐[5‐(1,7‐dicarba‐closo‐dodecaboranyl)‐3‐trifluoromethyl‐1H‐pyrazol‐1‐yl]‐1‐methylsulfonylbenzene).
Synthesis and Anticancer Evaluation of 1,4‐Naphthoquinone Derivatives Containing a Phenylaminosulfanyl Moiety
Authors: Ravichandiran Palanisamy , Subramaniyan Sivakumar Allur , Kim Seon‐Young , Kim Jong‐Soo , Park Byung‐Hyun , Shim Kwan Seob , Yoo Dong Jin 
Published: January 2019

Abstract1,4‐Naphthoquinones are exceptional building blocks in organic synthesis and have been used to synthesize several well‐known pharmaceutically active agents. Herein we report the synthesis, structural characterization, and biological evaluation of new phenylaminosulfanyl‐1,4‐naphthoquinone derivatives. We evaluated the cytotoxic activity of the synthesized compounds against three human cancer cell lines: A549, HeLa, and MCF‐7. Most of the synthesized compounds displayed potent cytotoxic activity. Specifically, compounds 5 e [3,5‐dichloro‐N‐(4‐((4‐((1,4‐dioxo‐3‐(phenylthio)‐1,4‐dihydronaphthalen‐2‐yl)amino)phenyl)sulfonyl)phenyl)benzamide], 5 f [N‐(4‐((4‐((1,4‐dioxo‐3‐(phenylthio)‐1,4‐dihydronaphthalen‐2‐yl)amino)phenyl)sulfonyl)phenyl)‐3,5‐dinitrobenzamide], and 5 p [N‐(4‐((4‐((1,4‐dioxo‐3‐(phenylthio)‐1,4‐dihydronaphthalen‐2‐yl)amino)phenyl)sulfonyl)phenyl)thiophene‐2‐carboxamide] showed remarkable cytotoxic activity. The synthesized compounds showed low toxicity in normal human kidney HEK293 cells. The cytotoxic mechanism of compounds 5 e, 5 f, and 5 p was explored in MCF‐7 cells. The results confirmed that these three compounds induce apoptosis and arrest the cell cycle at the G1 phase. In addition, compounds 5 e, 5 f, and 5 p were found to induce apoptosis via upregulation of caspase‐3 and caspase‐7 proteins as well as by upregulation of the gene expression levels of caspases‐3 and ‐7. Our findings demonstrate that compounds 5 e, 5 f, and 5 p could be potent agents against a number of cancer types.
Magnetic Traits in CoO‐Core@CoFe2O4‐shell Like Nanoparticles
Authors: Flores‐Martinez Nancy , Roemer Margot , Gam‐Derouich Sarra , Beaunier Patricia , Habrovsky David , Ammar Souad 
Published: January 2019

AbstractAntiferromagnetic (AF) CoO pseudo‐single crystals 125±20 nm in diameter were prepared by forced hydrolysis in polyol and used as seeds to grow a poly‐ and nano‐crystalline (5 nm in diameter) ferrimagnetic (F) CoFe2O4 shell. Transmission electron microscopy (TEM) showed a certain epitaxy between the face‐centered cubic lattices of the AF rock‐salt core and the F spinel shell. Magnetometry measurements do not evidence any exchange bias feature between the two phases in direct contact. The hysteresis loops recorded between 7 and −7 T after cooling the composite particles from 400 K (between the Néel and the Curie temperatures of the AF and F phases, respectively) to 5 K, with and without a cooling magnetic field (μ0HFC=+7 T), are the same, meaning that the AF core does not allow any spin pinning on the CoFe2O4 nanocrystals. Nevertheless, differences exist between these magnetic data and those collected on two CoFe2O4 reference particles: the low temperature coercive field of the composite is between those of 5 nm sized single‐crystals and their assembly as submicrometer polycrystals. This order was also observed for the blocking temperature, although the constituting CoFe2O4 nanocrystals of all these particles, the composite and the two references, were the same. Advanced analysis by X‐ray diffraction and TEM established that the coherent crystallographic domain length of the ferrite phase and the magnetic behavior of the three systems are interdependent. Depending on the growth conditions of the CoFe2O4 phase, a relative epitaxy between the nanocrystals may exist. It is much greater in the polycrystalline CoFe2O4 particles than in their CoO−CoFe2O4 core‐shell counterparts, and does not occur in free single crystal CoFe2O4 particles.
Electrochemical Characterization of Graphene Microelectrodes for Biological Applications
Authors: Körbitzer Berit , Krauß Peter , Belle Stefan , Schneider Jörg J. , Thielemann Christiane 
Published: January 2019

AbstractGraphene is a promising material both as a coating for existing neural electrodes as well as for transparent electrodes made exclusively from graphene. We studied graphene‐based microelectrodes by investigating their recording and stimulation properties in order to evaluate their suitability for neuronal implants. In this work, we compare three different electrode material compositions. Microelectrode arrays (MEA) with an electrode size of about 700 μm2 were prepared of gold, graphene on gold, and plain graphene on glass substrate. In order to reduce polymer contamination during graphene transfer, we employed a polymer‐free transfer and lift‐off process. Impedance studies revealed a value of 2.3 MΩ at 1 kHz for plain, and 0.88 MΩ for graphene on gold. Neuronal recording experiments showed a sufficient SNR for both graphene‐based materials and a stable impedance, unaffected by surface degradation metal electrodes are known for. Stimulation measurements yielded a charge injection capacity of 0.15 mC/cm2 using biphasic pulses of 1 ms and 1 μA transparent graphene electrodes. Cyclic voltammetry revealed a large voltage range of −1.4 V to +1.6 V before water electrolysis occurs. Graphene‐coated gold microelectrodes show enhanced recording properties, whereas plain graphene electrodes might be better suited for stimulation applications.
Selectivity in Photodynamic Action: Higher Activity of Mitochondria Targeting Photosensitizers in Cancer Cells
Authors: Ucar Esma , Seven Ozlem , Lee Dayoung , Kim Gyoungmi , Yoon Juyoung , Akkaya Engin U. 
Published: January 2019

AbstractAmong the pathways for improving the practice of photodynamic therapy of cancer, increasing the selectivity of photodynamic action is an obvious choice. Considering the different characteristics of mitochondria in normal cells and cancer cells, we designed mitochondria‐targeting photosensitizers. We now demonstrate for the first time that mitochondria‐targeted photosensitizers by triphenylphosphonium (TPP) derivatization are more selective for cancer cells compared to normal cells, presumably due to the larger membrane potential of cancer‐cell mitochondria allowing more efficient accumulation of the photosensitizer.