bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Supramolecular Species to Self‐Templated Porous Carbon and Metal‐Doped Carbon for Oxygen Reduction Reaction Catalysts
Authors: Xie Jin , Li Bo‐Quan , Peng Hong‐Jie , Song Yun‐Wei , Li Jia‐Xing , Zhang Ze‐Wen , Zhang Qiang 
Published: January 2019

AbstractThe preparation of carbon materials usually involves the decomposition of precursors and the reorganization of the as‐generated fragments. However, the cleavage of bonds and the simultaneous formation of new bonds at nearly the same positions prevents effective yet precise fabrication. Herein, a supramolecular precursor, cucurbit[6]uril, that contains multiple bonds with distinct bond strengths is proposed to decouple the twin problem of simultaneous bond cleavage and formation, allowing multistage transformations to hierarchical porous carbon and metal‐doped carbon in a single yet effective pyrolysis step without the need of a template or additional purification. As a proof‐of‐concept, the Fe‐doped carbon electrocatalysts realized a Pt/C‐like half‐wave potential of 0.869 V vs. RHE and small Tafel slope of 51.3 mV dec−1 in oxygen reduction reaction.
Biosynthesis and Ether‐Bridge Formation in Nargenicin Macrolides
Authors: Pidot Sacha J. , Herisse Marion , Sharkey Liam , Atkin Liselle , Porter Jessica L. , Seemann Torsten , Howden Benjamin P. , Rizzacasa Mark A. , Stinear Timothy P. 
Published: January 2019

AbstractThe nargenicin family of antibiotics are macrolides containing a rare ether‐bridged cis‐decalin motif. Several of these compounds are highly active against multi‐drug resistant organisms. Despite the identification of the first members of this family almost 40 years ago, the genetic basis for the production of these molecules and the enzyme responsible for formation of the oxa bridge, remain unknown. Here, the 85 kb nargenicin biosynthetic gene cluster was identified from a human pathogenic Nocardia arthritidis isolate and this locus is solely responsible for nargenicin production. Further investigation of this locus revealed a putative iron‐α‐ketoglutarate‐dependent dioxygenase, which was found to be responsible for the formation of the ether bridge from the newly identified deoxygenated precursor, 8,13‐deoxynargenicin. Uncovering the nargenicin biosynthetic locus provides a molecular basis for the rational bioengineering of these interesting antibiotic macrolides.
Amorphous Nanocages of Cu‐Ni‐Fe Hydr(oxy)oxide Prepared by Photocorrosion For Highly Efficient Oxygen Evolution
Authors: Cai Zhi , Li Lidong , Zhang Youwei , Yang Zhao , Yang Jie , Guo Yingjie , Guo Lin 
Published: January 2019

AbstractElectrochemical water splitting requires efficient, low‐cost water oxidation catalysts to accelerate the sluggish kinetics of the water oxidation reaction. A rapid photocorrosion method is now used to synthesize the homogeneous amorphous nanocages of Cu‐Ni‐Fe hydr(oxy)oxide as a highly efficient electrocatalyst for the oxygen evolution reaction (OER). The as‐fabricated product exhibits a low overpotential of 224 mV on a glassy carbon electrode at 10 mA cm−2 (even lower down to 181 mV when supported on Ni foam) with a Tafel slope of 44 mV dec−1 for OER in an alkaline solution. The obtained catalyst shows an extraordinarily large mass activity of 1464.5 A g−1 at overpotential of 300 mV, which is the highest mass activity for OER. This synthetic strategy may open a brand new pathway to prepare copper‐based ternary amorphous nanocages for greatly enhanced oxygen evolution.
Phosphorus‐Modulation‐Triggered Surface Disorder in Titanium Dioxide Nanocrystals Enables Exceptional Sodium‐Storage Performance
Authors: Xia Qingbing , Huang Yang , Xiao Jin , Wang Lei , Lin Zeheng , Li Weijie , Liu Hui , Gu Qinfen , Liu Hua Kun , Chou Shu‐Lei 
Published: January 2019

AbstractStructural modulation and surface engineering have remarkable advantages for fast and efficient charge storage. Herein, we present a phosphorus modulation strategy which simultaneously realizes surface structural disorder with interior atomic‐level P‐doping to boost the Na+ storage kinetics of TiO2. It is found that the P‐modulated TiO2 nanocrystals exhibit a favourable electronic structure, and enhanced structural stability, Na+ transfer kinetics, as well as surface electrochemical reactivity, resulting in a genuine zero‐strain characteristic with only approximately 0.1 % volume variation during Na+ insertion/extraction, and exceptional Na+ storage performance including an ultrahigh rate capability of 210 mAh g−1 at 50 C and a strong long‐term cycling stability without significant capacity decay up to 5000 cycles at 30 C.
Bifunctional Oxygen Electrocatalysts for Lithium−Oxygen Batteries
Authors: Bae Youngjoon , Park Hyeokjun , Ko Youngmin , Kim Hyunah , Park Sung Kwan , Kang Kisuk 
Published: January 2019

AbstractLithium−oxygen batteries have attracted great attention over the last few decades owing to their extraordinarily high theoretical energy density, which can potentially exceed that of current state‐of‐art lithium‐ion batteries. However, lithium−oxygen batteries exhibit poor cycle stability, relatively low power capability and significantly large polarizations for both, the oxygen reduction reaction (ORR, discharge) and the oxygen evolution reaction (OER, charge). To address these issues, various catalysts for aqueous and non‐aqueous lithium−oxygen batteries have thus been introduced, and some recent developments of bifunctional catalysts could simultaneously facilitate the ORR and OER, leading to great advancements in the overall battery performance. Herein, we present a brief overview of recent progress in the development of bifunctional catalysts for lithium−oxygen batteries based on the current understanding of their working mechanism. Perovskite‐type, spinel‐type, and non‐oxide catalysts and their use in aqueous lithium−oxygen batteries are reviewed. Recently reported bifunctional catalysts in non‐aqueous lithium−oxygen batteries are also introduced, and the different roles of solid‐ and soluble‐type catalysts are further discussed. Finally, we conclude by deliberating the design prospects and perspectives for efficient bifunctional catalysts for future lithium−oxygen batteries.
Association of ABC gene profiles with time to progression and resistance in ovarian cancer revealed by bioinformatics analyses
Authors: Seborova Karolina , Vaclavikova Radka , Soucek Pavel , Elsnerova Katerina , Bartakova Alena , Cernaj Petr , Bouda Jiri , Rob Lukas , Hruda Martin , Dvorak Pavel 
Published: January 2019

AbstractIntroductionOvarian cancer (OC) represents a serious disease with high mortality and lack of efficient predictive and prognostic biomarkers. ATP‐binding cassette (ABC) proteins constitute a large family dedicated to active transmembrane transport including transport of xenobiotics.Materials and methodsmRNA level was measured by quantitative RT‐PCR in tumor tissues from OC patients. Bioinformatics analyses were applied to two gene expression datasets (60 primary tumors and 29 peritoneal metastases). Two different approaches of expression data normalization were applied in parallel, and their results were compared. Data from publically available cancer datasets were checked to further validate our conclusions.ResultsThe results showed significant connections between ABC gene expression profiles and time to progression (TTP), chemotherapy resistance, and metastatic progression in OC. Two consensus ABC gene profiles with clinical meaning were documented. (a) Downregulation of ABCC4, ABCC10, ABCD3, ABCE1, ABCF1, ABCF2, and ABCF3 was connected with the best sensitivity to chemotherapy and TTP. (b) Oppositely, downregulation of ABCB11 and upregulation of ABCB1 and ABCG2 were connected with the worst sensitivity to chemotherapy and TTP. Results from publicly available online databases supported our conclusions.ConclusionThis study stressed the connection between two well‐documented ABC genes and clinicopathological features—ABCB1 and ABCG2. Moreover, we showed a comparable connection also for several other ABC genes—ABCB11, ABCC4, ABCC10, ABCD3, ABCE1, ABCF1, ABCF2, and ABCF3. Our results add new clinically relevant information to this oncology field and can stimulate further exploration.
Polypeptides secreted from the columnar vesicles of the sea anemone Bunodosoma cangicum and their in vivo effects on Caenorhabditis elegans
Authors: Bastos Claudio L.Q. , Josende Marcelo Estrella , Ferreira Shana Pires , de Magalhães Mariana Torquato Quezado , de Castro Pimenta Adriano Monteiro , Lima Juliane Ventura , Boyle Robert Tew 
Published: January 2019

AbstractIn this study we provide new evidence that the columnar vesicles of the sea anemone Bunodosoma cangicum are toxic in vivo and contain at least two active polypeptides, a neurotoxic and an apoptosis inducing polypeptide. Here we show that it is also an effective inducer of apoptosis in vivo in the nematode Caenorhabditis elegans. In addition, the anemone peptides rapidly paralyze C. elegans, and set in motion a sequence of events that result in the complete dissolution of the internal organs in adult animals within 60 min. Nematodes that survive the toxin treatment exhibit a decreased reproductive capacity. Interestingly, adult animals appear to be much more susceptible to the effects of the toxins than larval stages, suggesting possible developmentally dependent targets of the toxins. Here we also provide chemical characterization of the compounds through chromatographic analysis and mass spectrometry. Gel filtration chromatography coupled with reverse phase HPLC shows that our partially purified extract contains at least two principle components. Additionally, MALDI‐TOF mass spectrometry analysis of our extract shows three principal compounds at 814.6, 2914.1, and 4360.3 m/z plus three other minor components or fragments. Mass spectrometry analysis also indicates the presence of three disulfide bridges. Which is in agreement with other characterizations of anemone venoms.
M2‐polarized macrophages relate the clearance of gastric lanthanum deposition
Authors: Nakamura Takahito , Tsuchiya Atsunori , Kobayashi Masayoshi , Naito Makoto , Terai Shuji 
Published: January 2019

Key Clinical MessagePrevious reports have suggested that mucosal barrier failure allows lanthanum to stray into the lamina propria, and macrophages play an important role for the clearance. However, there is no report to analyze the polarity of phagocytizing macrophages. We suggested that M2 macrophage potentially played a major role in the clearance of lanthanum.
Constructing Earth‐abundant 3D Nanoarrays for Efficient Overall Water Splitting – A Review
Authors: Jamesh Mohammed‐Ibrahim , Kuang Yun , Sun Xiaoming 
Published: January 2019

AbstractConstructing nanoarrays is a promising way to achieve efficient overall water‐splitting for H2 production. At first, this paper introduces the significance of constructing nanoarrays for gas evolution reactions: Constructing electrocatalyst with nanoarray structure can provide superaerophobic surface, which can lower the bubble adhesive force and bubble size by forming a discontinuous triple phase contact line (TPCL), and that can facilitate the release of gas, while it can afford abundant active sites, and that can enhance the activity and stability for gas evolution reactions. Then, we review the activity (including ≤1.49 V), and stability (including ≥100 h) for overall water splitting in alkaline medium of various kinds of recently reported earth‐abundant 3D nanoarray bifunctional electrocatalysts. Later, we review the efficient strategies such as constructing nanoarrays with doping metals/heteroatoms, bimetallic/multi‐metallic materials, metal oxides, metal phosphide/phosphate, metal nitrides, carbon, amorphous materials, metal chalcogenides (metal sulfides and selenides), core‐shell/hetero/hollow structure, vacancies/defects, and well‐matched electrode pair to achieve efficient overall water splitting. Then, we review the construction of earth‐abundant nanoarray bifunctional electrocatalyst for efficient overall water splitting in acid medium. Finally, we discussed the gas separation in water electrolysis.
CuO/Graphene Nanocomposite for Nitrogen Reduction Reaction
Authors: Wang Fan , Liu Ya‐ping , Zhang Hu , Chu Ke 
Published: January 2019

AbstractElectrochemical conversion of N2 to NH3 offers a clean and energy‐saving solution for artificial NH3 production, but requires cost‐effective, steady and highly efficient catalysts to promote N2 reduction reaction (NRR). Herein, CuO employed as a new non‐noble‐metal NRR catalyst was investigated both experimentally and theoretically. When supporting the CuO nanoparticles on reduced graphene oxide (RGO), it was demonstrated that the resulting CuO/RGO nanocomposite could effectively and robustly catalyze NRR under ambient conditions. At −0.75 V versus reversible hydrogen electrode, the CuO/RGO exhibited a high NH3 yield of 1.8×10−10 mol s−1 cm−2 and Faradaic efficiency of 3.9 %, along with the excellent selectivity and high stability. Density functional theory (DFT) calculations revealed that the “Suf‐end” was the most effective mode for N2 adsorption on catalytic Cu atoms. In NRR process, the alternating associative route was the preferable pathway with *N2→*NNH being the rate‐determining step.
Rapid Screening of an Acid‐Catalyzed Triglyceride Transesterification in a Mesoscale Reactor
Authors: Al-Saadi Luma Shihab , Alegría Alexandra , Eze Valentine C. , Harvey Adam P. 
Published: January 2019

AbstractA mesoscale oscillatory baffled reactor (meso‐OBR) served as a continuous screening platform to rapidly investigate the operating conditions for acid‐catalyzed production of fatty acid methyl ester (FAME) from triglyceride feedstock. The acid catalyst was 4‐dodecylbenzenesulfonic acid (DBSA) and the triglyceride feedstock was rapeseed oil (RSO). The parameter space was explored by means of a design of experiments (DoE) methodology. The variables screened were methanol‐to‐RSO molar ratio, catalyst‐to‐oil molar ratio, and residence time. Over 98 % conversion of RSO to FAME could be achieved under optimized conditions.
Epitaxial Crystallization of Insulin on an Ordered 2D Polymer Template
Authors: de Poel Wester , Elemans Johannes A. A. W. , van Enckevort Willem J. P. , Rowan Alan E. , Vlieg Elias 
Published: January 2019

AbstractTwo‐dimensional polymers (2DP) are a new class of materials that consist of a monolayer of ordered molecular building blocks, which have been covalently linked. One of these monomers was self‐assembled on a flat muscovite mica scaffold and subsequently the organic layer was polymerized. The resulting flat and stable 2DP layer was used as a template for protein crystallization. Crystals of insulin were epitaxially grown on the template, whereas insulin crystals grown on clean muscovite mica had a random orientation. The template was selective, considering that no epitaxially ordered crystals formed of hen egg white lysozyme, bovine serum albumin, or talin.
The Hunt for Elusive Molecules: Insights from Joint Theoretical and Experimental Investigations
Authors: Martin‐Drumel Marie‐Aline , Baraban Joshua H. , Changala P. Bryan , Stanton John F. , McCarthy Michael C. 
Published: January 2019

AbstractRotational spectroscopy is an invaluable tool to unambiguously determine the molecular structure of a species, and sometimes even to establish its very existence. This article illustrates how experimental and theoretical state‐of‐the‐art tools can be used in tandem to investigate the rotational structure of molecules, with particular emphasis on those that have long remained elusive. The examples of three emblematic species—gauche‐butadiene, disilicon carbide, and germanium dicarbide—highlight the close, mutually beneficial interaction between high‐level theoretical calculations and sensitive microwave measurements. Prospects to detect other elusive molecules of chemical and astronomical interest are discussed.
Recent Advances in the Core‐Annulation of Naphthalene Diimides
Authors: Insuasty Alberto , Maniam Subashani , Langford Steven J. 
Published: January 2019

AbstractThis review focuses on describing all known synthetic strategies leading to core‐annulation of naphthalene diimides (NDIs). Strategies presented involve the formation of four‐, five‐ and six‐membered ring annulations bearing different heteroatomic and carbocyclic derivatives, including annulenes. The core‐annulation method opens the possibility for obtaining designer molecules with tuneable electronic characteristics such as a reduced energy band gap, and enhanced intermolecular overlap of π‐systems that improve electronic coupling between molecules—which is highly desirable for charge transport properties summarised in the final pages for applications in electronic devices such as organic field‐effect transistors (OFETs) and organic photovoltaic (OPV) cells. Molecular recognition in pH and fluoride sensing, or as a DNA probe, are some of additional applications of core‐annulated NDIs presented here. Additionally, recent advances in core modification of NDIs are presented, opening an entire new chemical avenue to be explored. Finally, the outlook on the future prospect of annulated NDIs in various applications is summarised.
Concise Total Synthesis of (−)‐Vermiculine through a Rhodium‐Catalyzed C2‐Symmetric Dimerization Strategy
Authors: Steib Philip , Breit Bernhard 
Published: January 2019

AbstractA short and efficient synthesis of the C2‐symmetric antibiotic (−)‐vermiculine by utilizing an enantioselective catalytic one‐step dimerization methodology as key‐step to construct the core structure is reported. The late‐stage modifications feature a double metathesis homologation followed by a double Wacker‐type oxidation. These key‐steps allowed the synthesis of vermiculine in only seven steps, starting from commercially available building blocks.
A study on how students handle Internet forums and possible consequences for chemistry education
Authors: Dittmar Johanna , Eilks Ingo 
Published: January 2019

AbstractDigitale Medien spielen in der heutigen Gesellschaft eine immer größere Rolle. Zentral dafür ist das Internet. Dies stellt die Gesellschaft und auch unsere Schülerinnen und Schüler mit den vielfältigen Informations‐ und Austauschmöglichkeiten vor immer neue Herausforderungen. Dieser Artikel stellt eine Befragung von 668 Schülerinnen und Schülern vor. Die Studie untersucht die Bekanntheit von, den Umgang mit sowie die Interessen Jugendlicher in Internetforen. Der Artikel diskutiert auch Konsequenzen, die sich daraus für den Chemieunterricht ergeben.
Encapsulation of the Dinuclear Trithiolato‐Bridged Arene Ruthenium Complex Diruthenium‐1 in an Apoferritin Nanocage: Structure and Cytotoxicity
Authors: Petruk Ganna , Monti Daria Maria , Ferraro Giarita , Pica Andrea , D'Elia Luigi , Pane Francesca , Amoresano Angela , Furrer Julien , Kowalski Konrad , Merlino Antonello 
Published: January 2019

AbstractThe effects of encapsulating the cytotoxic dinuclear trithiolato‐bridged arene ruthenium complex [(η6‐p‐MeC6H4iPr)2Ru2(μ2‐S‐p‐C6H4tBu)3]Cl (DiRu‐1) within the apoferritin (AFt) nanocage were investigated. The DiRu‐1‐AFt nanocarrier was characterized by UV/Vis spectroscopy, ICP‐MS, CD and X‐ray crystallography. In contrast to previously reported Au‐ and Pt‐based drug‐loaded AFt carriers, we found no evidence of direct interactions between DiRu‐1 and AFt. DiRu‐1‐AFt is cytotoxic toward immortalized murine BALB/c‐3T3 fibroblasts transformed with SV40 virus (SVT2) and human epidermoid carcinoma A431 malignant cells, and exhibits moderate selectivity for these cancer cells over normal BALB/c‐3T3 cells. DiRu‐1‐AFt triggers the production of reactive oxygen species, depolarization of mitochondrial membrane potential, and induces cell death via p53‐mediated apoptosis. Comparison between our data and previous results suggests that the presence of specific interactions between a metal‐based drug and AFt within the protein cage is not essential for drug encapsulation.
Finite Morse Index Implies Finite Ends
Authors: Wang Kelei , Wei Juncheng 
Published: January 2019

AbstractWe prove that finite Morse index solutions to the Allen‐Cahn equation in ℝ2 have finitely many ends and linear energy growth. The main tool is a curvature decay estimate on level sets of these finite Morse index solutions, which in turn is reduced to a problem on the uniform second‐order regularity of clustering interfaces for the singularly perturbed Allen‐Cahn equation. Using an indirect blowup technique, in the spirit of the classical Colding‐Minicozzi theory in minimal surfaces, we show that the obstruction to the uniform second‐order regularity of clustering interfaces in ℝn is associated to the existence of nontrivial entire solutions to a (finite or infinite) Toda system in ℝn–1. For finite Morse index solutions in ℝ2, we show that this obstruction does not exist by using information on stable solutions of the Toda system. © 2019 Wiley Periodicals, Inc.
Ultra‐Weak Metal−Metal Bonding: Is There a Beryllium‐Beryllium Triple Bond?
Authors: Rohman Shahnaz S. , Kashyap Chayanika , Ullah Sabnam S. , Guha Ankur K. , Mazumder Lakhya J. , Sharma Pankaz. K. 
Published: January 2019

AbstractMetal‐metal triple bonds featurings‐block element have not been reported until now. Only Be−Be double bonds between have been predicted theoretically based on the intuitive electron donation from fours1type electron‐donating ligands. Herein, we theoretically predicted a novel species featuring a Be−Be triple bond in the Li6Be2molecule. The molecule was found to be thermodynamically stable. The presence of the triple bond was confirmed by adaptive natural density partitioning (AdNDP), electron localization function (ELF), and atoms in molecules (AIM) analyses. Moreover, the mechanical strength of the Be−Be triple bond was analyzed by using compliance matrix, pointing towards its ultra‐weak nature.
Assembling All‐Solid‐State Lithium–Sulfur Batteries with Li3N‐Protected Anodes
Authors: Kızılaslan Abdulkadir , Akbulut Hatem 
Published: January 2019

AbstractThe construction of all‐solid‐state batteries is now easier after the successful synthesis of sulfur‐based solid electrolytes with extremely high ionic conductivities. Utilizing lithium metal as the anode in these batteries requires a protective solid electrolyte layer to prevent corrosion due to the highly reactive nature of lithium. Li3N coating on lithium metal is a promising way of preventing the degradation of the electrolyte during charge and discharge. In this study, utilization of a Li3N‐coated lithium anode and Li7P3S11 solid electrolyte are reported, where a quaternary reduced graphene oxide (rGO)/S/carbon black/Li7P3S11 composite is used as cathode in the assembled cell. Our results indicate that protecting the Li metal with a Li3N coating does not affect the electrochemical characteristics of the cell and extends the cycle life of the battery. A cell assembled with a protective layer was shown to having 306 mAh g−1 capacity after 120 cycles at 160 mAh g−1 current density, whereas a cell without protective layer had a capacity of 260 mAh g−1.