bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microscopic and Mesoscopic Dual Postsynthetic Modifications of Metal–Organic Frameworks
Authors: Lee Byeongchan , Moon Dohyun , Park Jinhee 
Published: April 2020

AbstractWe report the dual postsynthetic modification (PSM) of a metal–organic framework (MOF) involving the microscopic conversion of C−H bonds into C−C bonds and the mesoscopic introduction of hierarchical porosity. MOF crystals underwent single‐crystal‐to‐single‐crystal transformations during the electrophilic aromatic substitution of Co2(m‐DOBDC) (m‐DOBDC4−=4,6‐dioxo‐1,3‐benzenedicarboxylate) with alkyl halides and formaldehyde. The steric hindrance caused by the proximity of the introduced functional groups to the coordination bonds reduced bond stability and facilitated the transformation into hierarchically porous mesostructures by etching with in situ generated protons (hydroniums) and halides. The numerous defect sites in the mesostructural MOFs are potential water‐sorption sites. However, since the introduced functional groups are close to the main adsorption sites, even methyl groups are able to considerably decrease water adsorption, whereas hydroxy groups increase adsorption at low vapor pressures.
Discovery of a Novel Mycobacterial F‐ATP Synthase Inhibitor and its Potency in Combination with Diarylquinolines
Authors: Hotra Adam , Ragunathan Priya , Ng Pearly Shuyi , Seankongsuk Pattarakiat , Harikishore Amaravadhi , Sarathy Jickky Palmae , Saw Wuan‐Geok , Lakshmanan Umayal , Sae‐Lao Patcharaporn , Kalia Nitin Pal , Shin Joon , Kalyanasundaram Revathy , Anbarasu Sivaraj , Parthasarathy Krupakar , Pradeep Chaudhari Namrata , Makhija Harshyaa , Dröge Peter , Poulsen Anders , Tan Jocelyn Hui Ling , Pethe Kevin , Dick Thomas , Bates Roderick W. , Grüber Gerhard 
Published: April 2020

AbstractThe F1FO‐ATP synthase is required for growth and viability of Mycobacterium tuberculosis and is a validated clinical target. A mycobacterium‐specific loop of the enzyme's rotary γ subunit plays a role in the coupling of ATP synthesis within the enzyme complex. We report the discovery of a novel antimycobacterial, termed GaMF1, that targets this γ subunit loop. Biochemical and NMR studies show that GaMF1 inhibits ATP synthase activity by binding to the loop. GaMF1 is bactericidal and is active against multidrug‐ as well as bedaquiline‐resistant strains. Chemistry efforts on the scaffold revealed a dynamic structure activity relationship and delivered analogues with nanomolar potencies. Combining GaMF1 with bedaquiline or novel diarylquinoline analogues showed potentiation without inducing genotoxicity or phenotypic changes in a human embryonic stem cell reporter assay. These results suggest that GaMF1 presents an attractive lead for the discovery of a novel class of anti‐tuberculosis F‐ATP synthase inhibitors.
Predictable Selectivity in Remote C−H Oxidation of Steroids: Analysis of Substrate Binding Mode
Authors: Olivo Giorgio , Capocasa Giorgio , Ticconi Barbara , Lanzalunga Osvaldo , Di Stefano Stefano , Costas Miquel 
Published: April 2020

AbstractPredictability is a key requirement to encompass late‐stage C−H functionalization in synthetic routes. However, prediction (and control) of reaction selectivity is usually challenging, especially for complex substrate structures and elusive transformations such as remote C(sp3)−H oxidation, as it requires distinguishing a specific C−H bond from many others with similar reactivity. Developed here is a strategy for predictable, remote C−H oxidation that entails substrate binding to a supramolecular Mn or Fe catalyst followed by elucidation of the conformation of the host‐guest adduct by NMR analysis. These analyses indicate which remote C−H bonds are suitably oriented for the oxidation before carrying out the reaction, enabling prediction of site selectivity. This strategy was applied to late‐stage C(sp3)−H oxidation of amino‐steroids at C15 (or C16) positions, with a selectivity tunable by modification of catalyst chirality and metal.
Nicht in jedem Punkt schuldig: Der “nicht‐unschuldige” Nitrosyl‐Ligand in IUPACs Oxidationsstufen‐Empfehlung
Authors: Ampßler Torsten , Monsch Georg , Popp Jens , Riggenmann Tobias , Salvador Pedro , Schröder Daniel , Klüfers Peter 
Published: April 2020

AbstractDie Bindung eines Nitrosyl‐Liganden an ein Zentralmetallatom wird durch die Wechselwirkung zwischen den beiden N−O‐π*‐ und zwei Metall‐d‐Orbitalen bestimmt. Diese beiden (Rück‐)Bindungen sind weitgehend kovalent, wodurch deren Zuordnung bei der Oxidationsstufenbestimmung erschwert ist. Dabei erweist sich IUPACs “ionische Näherung” als wirksames Werkzeug, um auf der Grundlage der beteiligten Orbitale eine schlüssige Zuordnung zu erreichen – und zwar ohne den M‐N‐O‐Winkel oder Nettoladungen heranzuziehen.
Electrochemical Reduction of CO2 to Ethane through Stabilization of an Ethoxy Intermediate
Authors: Vasileff Anthony , Zhu Yanping , Zhi Xing , Zhao Yongqiang , Ge Lei , Chen Hao Ming , Zheng Yao , Qiao Shi‐Zhang 
Published: April 2020

AbstractElectrochemical conversion of CO2 into ethane is seldom observed because of the generally higher selectivity towards methane, ethylene, and ethanol. Consequently, little experimental evidence for its reaction mechanism exists and thus remains largely unknown. Now, by combining electrochemistry with in situ X‐ray absorption fine‐structure and in situ Raman techniques, iodide‐derived copper (ID‐Cu) and oxide‐derived copper (OD‐Cu) systems were studied to obtain a deeper understanding of the CO2 to ethane mechanism. With trace iodine species on the surface and positively charged Cu species, production of ethane is significantly more favored on ID‐Cu compared to OD‐Cu, with higher selectivity and faster kinetics. For the first time, it is experimentally found that the formation of ethane follows the same pathway to ethylene and ethanol, and better stabilization of the late stage ethoxy intermediate can steer the reaction to ethane over ethanol.
All‐Inorganic Lead‐Free 0D Perovskites by a Doping Strategy to Achieve a PLQY Boost from <2 % to 90 %
Authors: Han Peigeng , Luo Cheng , Yang Songqiu , Yang Yang , Deng Weiqiao , Han Keli 
Published: April 2020

AbstractZero‐dimensional (0D) lead‐free perovskites have unique structures and optoelectronic properties. Undoped and Sb‐doped all inorganic, lead‐free, 0D perovskite single crystals A2InCl5(H2O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H2O, Sb‐doped A3InCl6 (A=Rb, Cs) are also synthesized and further studied. The photoluminescence (PL) color changes from yellow to green emission. Interestingly, the photoluminescence quantum yield (PLQY) realizes a great boost from <2 % to 85–95 % through doping Sb3+. We further explore the effect of Sb3+ dopants and the origin of bright emission by ultrafast transient absorption techniques. Furthermore, Sb‐doped 0D rubidium indium chloride perovskites show excellent stability. These findings not only provide a way to design a set of new high‐performance 0D lead‐free perovskites, but also reveal the relationship between structure and PL properties.
The influences of powder surface energy on the dispersibility technology of polyvinyl alcohol fiber
Authors: Zhao Chunhua , Liang Naixing , Zhu Xiaolong 
Published: April 2020

AbstractIn order to quantitatively analyze the effect of powder on fiber dispersion, the surface free energy theory was applied to test the surface free energy parameters of each powder based on the “capillary rise method”. Then, the surface free energy of each powder was further calculated. Finally, based on a certain ratio, the fiber reinforced cement was formed. In terms of the test piece, the profile of the cement slurry was imaged through the method of scanning electron microscopy. Through the image, the distribution of the fiber in the profile was quantified, and the relationship between the free energy of the powder surface and the distribution of the fiber in the cement slurry was clarified. It indicates that there is a strong correlation between the dispersibility and the surface energy of the powder. The greater the surface energy of the powder, the higher the distribution coefficient of the fiber in the cement paste.
High‐throughput fabrication of carbonized electrospun polyacrylonitrile/poly(acrylic acid) nanofibers with additives for enhanced electrochemical sensing
Authors: Tan Huey Ling , Sanira Putri Maria Kana , Idris Siti Shawalliah , Hartikainen Niklas , Abu Bakar Noor Fitrah , Keirouz Antonios , Radacsi Norbert 
Published: April 2020

AbstractLightweight, polyacrylonitrile‐derived electrodes with different additives were fabricated using high‐throughput nozzle‐free electrospinning. The electrospun precursor nanofibers (PNFs) containing iron oxide, gold nanoparticles, or reduced graphene oxide (rGO) were subjected to oxidative stabilization and carbonization to obtain a carbon‐rich conductive nanofiber structure. Scanning electron microscopy showed that the carbon nanofibers contracted between 11 and 55% while the Fourier‐transform infrared spectroscopy confirmed that the carbon nanofibers were thermally stable. Thermogravimetric and differential scanning calorimetry results revealed that the cross‐linking of the chain molecules and cyclization were completed. Next, cyclic voltammetry results indicated that the electroactivity of the modified screen‐printed carbon electrodes was decreased by 85% due to the presence of carbon glue. The modified device presented significant enhanced electrochemical responses with the inclusions of nanoparticles, with rGO showing a 2.13 times higher electroactive surface area, followed by iron oxide (two times) and gold nanoparticles (1.37 times) than the equivalent PNFs.
Mitochondrial Dysfunction in Schizophrenia
Authors: Ni Peiyan , Chung Sangmi 
Published: April 2020

AbstractSchizophrenia (SCZ) is a severe neurodevelopmental disorder affecting 1% of populations worldwide with a grave disability and socioeconomic burden. Current antipsychotic medications are effective treatments for positive symptoms, but poorly address negative symptoms and cognitive symptoms, warranting the development of better treatment options. Further understanding of SCZ pathogenesis is critical in these endeavors. Accumulating evidence has pointed to the role of mitochondria and metabolic dysregulation in SCZ pathogenesis. This review critically summarizes recent studies associating a compromised mitochondrial function with people with SCZ, including postmortem studies, imaging studies, genetic studies, and induced pluripotent stem cell studies. This review also discusses animal models with mitochondrial dysfunction resulting in SCZ‐relevant neurobehavioral abnormalities, as well as restoration of mitochondrial function as potential therapeutic targets. Further understanding of mitochondrial dysfunction in SCZ may open the door to develop novel therapeutic strategies that can address the symptoms that cannot be adequately addressed by current antipsychotics alone.
Changes in the left temporal microstate are a sign of cognitive decline in patients with Alzheimer’s disease
Authors: Musaeus Christian S. , Engedal Knut , Høgh Peter , Jelic Vesna , Khanna Arjun R. , Kjær Troels Wesenberg , Mørup Morten , Naik Mala , Oeksengaard Anne‐Rita , Santarnecchi Emiliano , Snaedal Jon , Wahlund Lars‐Olof , Waldemar Gunhild , Andersen Birgitte B. 
Published: April 2020

AbstractIntroductionLarge‐scale brain networks are disrupted in the early stages of Alzheimer's disease (AD). Electroencephalography microstate analysis, a promising method for studying brain networks, parses EEG signals into topographies representing discrete, sequential network activations. Prior studies indicate that patients with AD show a pattern of global microstate disorganization. We investigated whether any specific microstate changes could be found in patients with AD and mild cognitive impairment (MCI) compared to healthy controls (HC).Materials and methodsStandard EEGs were obtained from 135 HC, 117 patients with MCI, and 117 patients with AD from six Nordic memory clinics. We parsed the data into four archetypal microstates.ResultsThere was significantly increased duration, occurrence, and coverage of microstate A in patients with AD and MCI compared to HC. When looking at microstates in specific frequency bands, we found that microstate A was affected in delta (1–4 Hz), theta (4–8 Hz), and beta (13–30 Hz), while microstate D was affected only in the delta and theta bands. Microstate features were able to separate HC from AD with an accuracy of 69.8% and HC from MCI with an accuracy of 58.7%.ConclusionsFurther studies are needed to evaluate whether microstates represent a valuable disease classifier. Overall, patients with AD and MCI, as compared to HC, show specific microstate alterations, which are limited to specific frequency bands. These alterations suggest disruption of large‐scale cortical networks in AD and MCI, which may be limited to specific frequency bands.
Bilateral femoral fractures during birth, in a neonate with malformation complex with stiffness
Authors: Laliotis Nikolaos , Tsoni Konstantia , Konstantinidis Panagiotis , Agakidou Eleni , Chrysanthou Chrysanthos 
Published: April 2020

AbstractFetuses with prenatal diagnosis of reduced mobility and malformation are at increased risk to sustain neonatal femoral fractures. Labor difficulties even after an elective cesarean section may trigger the fractures of the long bones.
Self‐Supported CoP Nanoparticle‐Embedded Wood‐Derived Porous Carbon Membrane for Efficient H2 Evolution in Both Acidic and Basic Solutions
Authors: Min Shixiong , Deng Wanan , Li Yanan , Wang Fang , Zhang Zhengguo 
Published: April 2020

AbstractSelf‐supported carbon‐based electrocatalysts that possess good structural integrity, high activity, and excellent stability are being extensively pursued for applications in practical electrochemical energy conversion devices. Herein, we report a nature‐inspired and straightforward strategy to fabricate a self‐supported CoP nanoparticle‐embedded wood‐derived porous carbon membrane (CoP@PCM) as a highly efficient and stable electrocatalyst for the hydrogen evolution reaction (HER) in both acidic and basic solutions. Benefitting from the numerous aligned microchannels and high porosity of PCM, as well as the high dispersion of CoP nanoparticles, the as‐fabricated CoP@PCM demonstrates superior electrocatalytic activity for HER, with overpotentials of 155 and 112 mV in 0.5 M H2SO4 and 1.0 M KOH, respectively, at a current density of 10 mA cm−2. In addition, CoP@PCM also exhibits good durability for HER at a high current density of ∼100 mA cm−2 in both solutions over 8 h of HER electrolysis, showing its great potential as a practical electrocatalyst for large‐scale electricity‐to‐fuel conversion.
Multiple Methane Activation Pathways on Ga‐modified ZSM‐5 Zeolites Revealed by Solid‐State NMR Spectroscopy
Authors: Zhao Xingling , Xu Jun , Chu Yueying , Qi Guodong , Wang Qiang , Gao Wei , Li Shenhui , Feng Ningdong , Deng Feng 
Published: April 2020

AbstractMethane activation on Ga‐modified ZSM‐5 zeolites (Ga/ZSM‐5) was studied by solid‐state NMR spectroscopy. Two types of Ga species, namely highly dispersed oxides and cationic Ga species, were determined by 71Ga QCPMG NMR. The activation of methane on Ga/ZSM‐5 was explored by using 13C and 1H MAS NMR. Four types of Ga‐CH3 species along with Ga‐OH groups were observed on Ga/ZSM‐5, evidencing different pathways for heterolytic cleavage of C−H bond of methane. Two‐dimensional (2D) 1H‐1H correlation NMR experiments provide detailed information on the location and local environment of the Ga‐CH3 species by correlating the protons in Ga‐CH3 with those in Ga‐OH and other hydroxyls on zeolite. The structures of different Ga‐CH3 species were further determined by 2D 1H‐13C heteronuclear correlation NMR experiments, which were supported by theoretical calculations. The activation routes of C−H bond in methane were proposed on Ga/ZSM‐5 zeolite.
Nitrogen‐Immobilized, Ionic Liquid‐Derived, Nitrogen‐Doped, Activated Carbon for Supercapacitors
Authors: Kim Juyeon , Jeong Jun Hui , Ahn Hyo‐Jun , Lee Je Seung , Roh Kwang Chul 
Published: April 2020

AbstractTo synthesize nitrogen‐remained activated carbon (AC) following KOH activation, nitrile‐functionalized ionic liquid (IL) that immobilizes nitrogen atoms in the form of aromatic amines, such as graphitic, pyridinic, or pyrrolic nitrogen, was synthesized and used as a carbon precursor. Aromatic amines are more robust in adverse conditions than aliphatic amines. The nitrogen‐doped (N‐doped) AC was prepared by activating the carbon derived from the nitrile‐functionalized IL that acts as both a carbon precursor and a nitrogen‐doping source. The N‐doped AC had an optimized doped nitrogen and porous structure, and was prepared by controlling the activation conditions. The nitrogen residue in the N‐doped AC after KOH activation enhanced electrochemical properties of the N‐doped AC. Thus, it is important to use a carbon precursor that includes immobilized nitrogen to effectively prepare the AC after the KOH activation.
Library Design Strategies To Accelerate Fragment‐Based Drug Discovery
Authors: Troelsen Nikolaj S. , Clausen Mads H. 
Published: April 2020

AbstractFragment‐based drug discovery (FBDD) has become an established approach for the generation of early lead candidates. However, despite its success and inherent advantages, hit‐to‐candidate progression for FBDD is not necessarily faster than that of traditional high‐throughput screening. Thus, new technology‐driven library design strategies have emerged as a means to facilitate more efficient fragment screening and/or subsequent fragment‐to‐hit chemistry. This minireview discusses such strategies, which cover the use of labeled fragments for NMR spectroscopy, X‐ray crystallographic screening of specialized fragments, covalent linkage for mass spectrometry, dynamic combinatorial chemistry, and fragments optimized for easy elaboration.
New Visible‐Light‐Triggered Photocatalytic Trifluoromethylation Reactions of Carbon–Carbon Multiple Bonds and (Hetero)Aromatic Compounds
Authors: Barata‐Vallejo Sebastian , Postigo Al 
Published: April 2020

AbstractVisible‐light‐photocatalyzed methods employed in synthetic transformations present attractive properties such as environmentally friendly, safety, availability and excellent functional group tolerance. In this regard, research on the visible‐light photocatalytic incorporation of the trifluoromethyl CF3 moiety into organic substrates, in particular, has contributed to a clear evolution of the field of photocatalysis. Although this particular area is constantly evolving and has been reviewed, the last five years have experienced an outburst of seminal and significant photocatalytic trifluoromethylation examples that are leading the way and opening new synthetic avenues. Recent review articles on Ru‐ and Ir‐based photocatalytic trifluoromethylation reactions have borne witness of this evolution. Although this account will show the new Ru‐ and Ir‐based photocatalytic trifluoromethylations, Sections 2 and 3 will also illustrate other photocatalytic systems, such as organic dyes, organic semiconductors and newly‐developed all‐organic photocatalysts. All the known and reviewed strategies for photocatalytic trifluoromethylation reactions of olefins and (hetero)aromatic compounds will not be discussed but will be summarized in two figures (Figures 4 and 5), and new examples (2015–present) will be presented and discussed.
A Designed Durable Electrolyte for High‐Voltage Lithium‐Ion Batteries and Mechanism Analysis
Authors: Zou Yeguo , Shen Yabin , Wu Yingqiang , Xue Hongjin , Guo Yingjun , Liu Gang , Wang Limin , Ming Jun 
Published: April 2020

AbstractRechargeable lithium‐ion batteries (LIBs) dominate the energy market, from electronic devices to electric vehicles, but pursuing greater energy density remains challenging owing to the limited electrode capacity. Although increasing the cut‐off voltage of LIBs (>4.4 V vs. Li/Li+) can enhance the energy density, the aggravated electrolyte decomposition always leads to a severe capacity fading and/or expiry of the battery. Herein, a new durable electrolyte is reported for high‐voltage LIBs. The designed electrolyte is composed of mixed linear alkyl carbonate solvent with certain cyclic carbonate additives, in which use of the ethylene carbonate (EC) co‐solvent was successfully avoided to suppress the electrolyte decomposition. As a result, an extremely high cycling stability, rate capability, and high‐temperature storage performance were demonstrated in the case of a graphite|LiNi0.6Co0.2Mn0.2O2(NCM622) battery at 4.45 V when this electrolyte was used. The good compatibility of the electrolyte with the graphite anode and the mitigated structural degradation of the NCM622 cathode are responsible for the high performance at high potentials above 4.4 V. This work presents a promising application of high‐voltage electrolytes for pursuing high energy LIBs and provides a straightforward guide to study the electrodes/electrolyte interface for higher stability.
Metal‐ and Reagent‐Free Electrochemical Synthesis of Alkyl Arylsulfonates in a Multi‐Component Reaction
Authors: Blum Stephan P. , Schollmeyer Dieter , Turks Maris , Waldvogel Siegfried R. 
Published: April 2020

AbstractThis work presents the first electrochemical preparation of alkyl arylsulfonates by direct anodic oxidation of electron‐rich arenes. The reaction mechanism features a multi‐component reaction consisting of electron‐rich arenes, an alcohol of choice and excess SO2 in an acetonitrile‐HFIP reaction mixture. In‐situ formed monoalkyl sulfites are considered as key intermediates with bifunctional purpose. Firstly, this species functions as nucleophile and secondly, excellent conductivity is provided. Several primary and secondary alcohols and electron‐rich arenes are implemented in this reaction to form the alkyl arylsulfonates in yields up to 73 % with exquisite selectivity. Boron‐doped diamond electrodes (BDD) are employed in divided cells, separated by a simple commercially available glass frit.
A Supramolecular Counter Circuit Based on Cyanine Dye Assembly
Authors: Chen Die , Wu Zhiming , Xu Xiaoping , Yang Shu 
Published: April 2020

AbstractMolecular computation, a rapidly developing multidisciplinary research field, has attracted increasing attention. A series of combinational logic circuits at the molecular level have been constructed, however, the development of sequential logic circuits is still in its infancy due to the lack of ideal design tools. Taking advantage of unique assembly behaviors of cyanine dyes, we constructed a two‐bit molecular counter circuit that can implement fundamental sequential logic functions, including number cumulating and descending. Further introducing a guanine‐rich DNA strand as the cycle index, the counter can be reused several times and eventually be scaled up to count up to 16 numbers. The supramolecular circuit shows high programmability, flexibility, and reversibility, and it is prospected that the strategy would be applied in designing other advanced molecular circuits.