bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid‐Phase Exfoliation and Functionalization of MoS2 Nanosheets for Effective Antibacterial Application
Authors: Ma Dongqing , Xie Changjian , Wang Tao , Mei Linqiang , Zhang Xiao , Guo Zhao , Yin Wenyan 
Published: March 2020

AbstractA lysozyme (Lys)‐assisted liquid‐phase exfoliation technique was designed to synthesize MoS2 nanosheets (MoS2‐Lys NSs). As a novel nanozyme antibacterial agent with high peroxidase‐like catalyst activity, MoS2‐Lys NSs showed good antibacterial efficacy against both Gram‐negative ampicillin‐resistant Escherichia coli (Ampr E. coli) and Gram‐positive Bacillus subtilis. A possible antibacterial mechanism is also proposed. This work provides an effective antibacterial strategy based on the MoS2‐Lys NSs antibacterial agent.
Manganese Oxide Derived from a Spent Zn–C Battery as a Catalyst for the Oxygen Evolution Reaction
Authors: Farzana Rifat , Sayeed Md Abu , Joseph Jickson , Ostrikov Kostya (Ken) , O'Mullane Anthony P. , Sahajwalla Veena 
Published: March 2020

AbstractThe generation of efficient, cheap and easily available water splitting catalysts, in particular for the oxygen evolution reaction (OER), is vital to the development of sustainable energy sources. Primary batteries, especially alkaline and Zn−C batteries, mostly end‐up in landfill due to their short lifespan which aggravates health and poses environmental threats. To address these issues, this work establishes a sustainable route for the generation of Manganese oxide (Mn3O4) from spent Zn−C batteries as a catalyst for the OER under alkaline conditions. A thermal transformation study is conducted here at 900 °C and 800 °C under controlled atmosphere to generate Mn3O4 nanoparticles from waste Zn−C batteries which are investigated as a potential OER catalyst. Mn3O4 particle synthesis was confirmed by XRD, Raman, FTIR, TEM and EDS analysis. The electrochemical performance demonstrated a low overpotential of 360 mV to reach 10 mA cm−2 with a Tafel slope of 64 mV dec−1 indicating good activity under alkaline conditions. Thus, the generation of Mn3O4 from a spent Zn−C battery that can be employed as a catalyst for the OER is a promising path not only for the effective extraction of resources from battery waste, but also for the exploitation of using extracted materials in advanced technology applications.
Ambident Reactivity of Imidazolium Cations as Evidence of the Dynamic Nature of N‐Heterocyclic Carbene‐Mediated Organocatalysis
Authors: Galkin Konstantin I. , Karlinskii Bogdan Ya. , Kostyukovich Alexander Yu. , Gordeev Evgeniy G. , Ananikov Valentine P. 
Published: March 2020

AbstractThis work reveals ambident nucleophilic reactivity of imidazolium cations towards carbonyl compounds at the C2 or C4 carbene centers depending on the steric properties of the substrates and reaction conditions. Such an adaptive behavior indicates the dynamic nature of organocatalysis proceeding via a covalent interaction of imidazolium carbenes with carbonyl substrates and can be explained by generation of the H‐bonded ditopic carbanionic carbenes.
Cooperative and Independent Effect of Modular Functionalization on Mesomorphic Performances and Microphase Separation of Well‐Designed Liquid Crystalline Diblock Copolymers
Authors: Lei Lan , Han Li , Ma Hongwei , Zhang Ruixue , Huang Shuai , Shen Heyu , Yang Lincan , Li Chao , Zhang Songbo , Bai Hongyuan , Ma Qingchi , Li Yang 
Published: March 2020

AbstractLiquid crystalline block copolymers (LCBCPs) are promising for developing functional materials owing to an assembly of better functionalities. Taking advantage of differences in reactivity between alkynyl and vinyl over temperature during hydrosilylation, a series of LCBCPs with modular functionalization of the block copolymers (BCPs) are reported by independently and site‐selectively attaching azobenzene moieties containing alkynyl (LC1) and Si‐H (LC2) terminals into well‐designed poly(styrene)‐block‐polybutadienes (PS‐b‐PBs) and poly(4‐vinylphenyldimethylsilane)‐block‐polybutadienes (PVPDMS‐b‐PBs) produced from living anionic polymerization (LAP). By the principle of modular functionalization, it is demonstrated that mono‐functionalized (PVPDMS‐g‐LC1)‐b‐PB and PS‐b‐(PB‐g‐LC2) not only maintain independence but also have cooperative contributions to bi‐functionalized (PVPDMS‐g‐LC1)‐b‐(PB‐g‐LC2) in terms of mesomorphic performances and microphase separation, which is evident from differential scanning calorimetry (DSC) and polarized optical morphologies (POM) and identified by powder X‐ray diffractions. With the application of the new principle of modular functionalization, local‐crosslinked liquid crystalline networks (LCNs) with controlled functionality are successfully synthesized, which show well‐controlled phase behaviors over molecular compositions.
Stepwise Oxidations in a Cofacial Copper(II) Porphyrin Dimer: Through‐Space Spin‐Coupling and Interplay between Metal and Radical Spins
Authors: Kumar Amit , Sanfui Sarnali , Sciortino Giuseppe , Maréchal Jean‐Didier , Garribba Eugenio , Rath Sankar Prasad 
Published: March 2020

Abstractcis and trans‐copper(II) porphyrin dimers have been synthesized, in which two CuII porphyrin macrocycles are bridged through a rigid ethene linker for possible through‐space and through‐bond spin‐couplings between the paramagnetic CuII centers. It has been found that the two macrocycles come closer after 1 e− oxidation, however, they move far apart upon further 1 e− oxidation leading to transformation of the cis to the trans isomer. Detailed investigations are performed here on the interactions between the two porphyrin macrocycles, between two unpaired spins of closely spaced CuII centers, and also between the unpaired spins of metal and porphyrin π–cation radicals. Spectroscopic investigations along with the X‐ray structure of the 2 e−‐oxidized complex displayed strong electronic communications through the bridge between two porphyrin π–cation radicals. The counterion I9− is stabilized in an unusual trigonal‐pyramidal structure in the 2 e−‐oxidized complex in which the central iodide ion is bound with four iodine (I2) molecules. Variable‐temperature magnetic study revealed strong antiferromagnetic coupling between the two porphyrin π–cation radical spins (Jr–r) in the 2 e−‐oxidized complex. DFT calculations suggest stabilization of the triplet state, which is also in good agreement with the experiment. Ab initio molecular dynamics allowed the variation of the structural details to be followed upon stepwise oxidations and also the final isomerization process including its associated energy barrier.
Evidence for Electron Transfer between Graphene and Non‐Covalently Bound π‐Systems
Authors: Brülls Steffen M. , Cantatore Valentina , Wang Zhenping , Tam Pui Lam , Malmberg Per , Stubbe Jessica , Sarkar Biprajit , Panas Itai , Mårtensson Jerker , Eigler Siegfried 
Published: March 2020

AbstractHybridizing graphene and molecules possess a high potential for developing materials for new applications. However, new methods to characterize such hybrids must be developed. Herein, the wet‐chemical non‐covalent functionalization of graphene with cationic π‐systems is presented and the interaction between graphene and the molecules is characterized in detail. A series of tricationic benzimidazolium salts with various steric demand and counterions was synthesized, characterized and used for the fabrication of graphene hybrids. Subsequently, the doping effects were studied. The molecules are adsorbed onto graphene and studied by Raman spectroscopy, XPS as well as ToF‐SIMS. The charged π‐systems show a p‐doping effect on the underlying graphene. Consequently, the tricationic molecules are reduced through a partial electron transfer process from graphene, a process which is accompanied by the loss of counterions. DFT calculations support this hypothesis and the strong p‐doping could be confirmed in fabricated monolayer graphene/hybrid FET devices. The results are the basis to develop sensor applications, which are based on analyte/molecule interactions and effects on doping.
Controlled Assembly of Cu/Co‐Oxide Beaded Nanoclusters on Thiolated Graphene Oxide Nanosheets for High‐Performance Oxygen Evolution Catalysts
Authors: Munir Akhtar , ul Haq Tanveer , Hussain Iqtidar , Ullah Irfan , Hussain Syed Zajif , Qurashi Ahsanulhaq , Iqbal Javed , Rehman Asma , Hussain Irshad 
Published: March 2020

AbstractThe use of water splitting modules is highly desired for the sustainable production of H2 as a future energy carrier. However, the sluggish kinetics and demand of high anodic potential are the bottlenecks for half‐the cell oxygen evolution reaction (OER), which severely hamper the overall conversion efficiency. Although transition metal oxides based electrocatalysts have been envisioned as cost‐effective and potential contenders for this quest, nevertheless, their low conductivity, instability, and limited number of active sites are among the common impediments that need to be addressed to eventually enhance their inherent catalytic potential for enhanced OER activity. Herein, the controlled assembly of transition metal oxides, that is, Cu@CuOx nanoclusters (NCs, ≈2 nm) and Co@CoOx beaded nanoclusters (BNCs, ≈2 nm), on thiol‐functionalized graphene oxide (G‐SH) nanosheets is reported to form novel and highly efficient electrocatalysts for OER. The thiol (‐SH) functionality was incorporated by selective epoxidation on the surface of graphene oxide (GO) to achieve chemically exfoliated nanosheets to enhance its conductivity and trapping ability for metal oxides in nanoscale dimensions (≈2 nm). During the electrocatalytic reaction, overpotentials of 290 mV and 310 mV are required to achieve a current density of 10 mA cm−2 for BNCs and NCs, respectively, and the catalysts exhibit tremendous long‐term stability (≈50 h) in purified alkaline medium (1 m KOH) with no dissolution in the electrolyte. Moreover, the smaller Tafel slopes (54 mV/dec for BNCs and 66 mV/dec for NCs), and a Faradic efficiency of approximately 96 % indicate not only the selectivity but also the tailored heterogeneous electrons transfer (HET) rate, which is required for fast electrode kinetics. It is anticipated that such ultrasmall metal oxide nanoclusters and their controlled assembly on a conducting surface (G‐SH) may offer high electrochemical accessibility and a plethora of active sites owing to the drastic decrease in dimensions and thus can synergistically ameliorate the challenging OER process.
Gold‐Catalyzed Cycloisomerization of Sulfur Ylides to Dihydrobenzothiepines
Authors: Knittl‐Frank Christian , Saridakis Iakovos , Stephens Thomas , Gomes Rafael , Neuhaus James , Misale Antonio , Oost Rik , Oppedisano Alberto , Maulide Nuno 
Published: March 2020

AbstractThe metal‐promoted nucleophilic addition of sulfur ylides to π‐systems is a well‐established reactivity. However, the driving force of such transformations, elimination of a sulfide moiety, entails stoichiometric byproducts making them unfavorable in terms of atom economy. In this work, a new take on sulfur ylide chemistry is reported, an atom‐economical gold(I)‐catalyzed synthesis of dihydrobenzo[b]thiepines. The reaction proceeds under mild conditions at room temperature.
Synthesis of Well‐Defined High‐Valent Palladium Complexes by Oxidation of Their Palladium(II) Precursors
Authors: Zhang Bo , Yan Xuechao , Guo Shuai 
Published: March 2020

AbstractThe last decade has witnessed the rapid development of high‐valent Pd‐involved organic transformations. This has also led to a steadily growing number of publications concerning the preparation of isolable and characterizable palladium(III) and palladium(IV) complexes. A variety of one‐electron and two‐electron oxidants have been employed to give access to high‐oxidation‐state Pd compounds. Undoubtedly, the study of these stoichiometric reactions has great implications for relevant Pd‐mediated catalysis. In this minireview, the focus is on the synthetic approaches to structurally determined PdIII/IV complexes starting from their PdII precursors, and the advances in this research area from early 2010 to late 2019 will be highlighted. Chemical oxidations exploiting various oxidizing agents including 1) hypervalent iodine reagents; 2) halogens; 3) electrophilic fluorination reagents; 4) alkyl/aryl halides; 5) ferrocenium salts; 6) peroxides/O2; 7) sulfonyl chlorides; and 8) others are covered. A “greener” electrooxidation manner has also been reviewed.
Investigation on effects of adapting chromaticities and luminance on color appearance on computer displays using memory colors
Authors: Zhu Yuechen , Wei Minchen , Luo Ming R. 
Published: March 2020

AbstractCAT02, the most widely used chromatic adaptation transform to characterize the chromatic adaptation mechanism in the human visual system, includes a factor D to characterize the degree of chromatic adaptation. This factor, however, is only determined by the luminance level of the adapting field and surround. This study was designed to investigate how the change of adapting chromaticities and the simultaneous changes of adapting chromaticities and luminance affect the degree of chromatic adaptation and color appearance on computer displays. The human observers adjusted the color appearance of various familiar objects and cubes on different display backgrounds. A higher degree of chromatic adaptation was found when using familiar objects, which was likely due to the cognitive mechanism. Both the adapting chromaticities and luminance significantly affected the degree of chromatic adaptation, with a lower degree under an adapting condition with a lower adapting correlated color temperature and a lower adapting luminance. In addition, the effect of adapting luminance on colorfulness (known as the Hunt Effect) was likely to be overpredicted in CAM02‐UCS, which merits further investigations.
Singlet Fission in Enantiomerically Pure Pentacene Dimers
Authors: Papadopoulos Ilias , Gao Yueze , Hetzer Constantin , Tykwinski Rik R. , Guldi Dirk M. 
Published: March 2020

AbstractSinglet fission (SF), that is, producing two triplet excited states (T1+T1) from a single singlet excited state (S1S0), has the potential to surpass the thermodynamic Shockley–Queisser limit for solar cells of 33 %. Of great relevance for singlet fission is the (S1S0)‐to‐1(T1T1) transformation as it is the key step in driving the efficiency of SF. In the current study, we focus on the control over intramolecular interactions in enantiomerically pure platinum linked pentacene dimers, (S,S)‐ and (R,R)‐cis‐Pt. Despite the internal heavy‐atom effect stemming from the presence of the Pt‐centered linkers, (S,S)‐ and (R,R)‐cis‐Pt undergo quantitative and solvent dependent formation of 1(T1T1). Implicit is an enantiomer‐independent SF mediation by means of a virtual CT intermediate in a superexchange mechanism. With the help of steady‐state and time‐resolved spectroscopic techniques, a kinetic model is developed to describe the entire deactivation pathway following photoexcitation of (S,S)‐ and (R,R)‐cis‐Pt.
Structure of Diethyl‐Phosphonic Acid Anchoring Group Affects the Charge‐Separated State on an Iridium(III) Complex Functionalized NiO Surface
Authors: Wahyuono Ruri Agung , Amthor Sebastian , Müller Carolin , Rau Sven , Dietzek Benjamin 
Published: March 2020

AbstractCyclometalated Iridium(III) complexes, i. e. [Ir(C N)2(dppz)][PF6], bearing either two or four ‐CH2PO(OH)2 anchoring groups (IrP2dppz or IrP4dppz) are explored as photosensitizers for p‐type dye sensitized solar cell (DSSC). The synthetic route is described and the iridium(III) complexes are characterized with respect to their electrochemical and photophysical properties. The modified anchoring ligand geometry exploited in this work not only alters the electronic nature of the complex (that is by destabilizing the LUMO energetically) but more importantly improves the grafting ability of the complex towards the NiO surface. The photoinduced long‐lived charge separated state (CSS) at the NiO|IrPxdppz interface is of a different nature comparing the two complexes. For IrP2dppz and IrP4dppz the electron density of the CSS dominantly resides on the dppz and the C N ligand, respectively. The stability of the CSS can be correlated to the solar cell performance in NiO‐based p‐DSSCs, which yield conversion efficiencies which are among the highest in the class of iridium(III) complexes developed for p‐DSSCs.
Bias in composite indexes of CSR practice: An analysis of CUR matrix decomposition
Authors: Amor‐Esteban Víctor , Galindo‐Villardón María Purificación , García‐Sánchez Isabel‐María 
Published: March 2020

AbstractThe main objective of this research is to propose the best aggregate index of corporate social responsibility practice at the organisational level. To achieve this, we analyse the consistency of the different aggregated measures that researchers use in their analyses through a robust statistical technique, the CUR matrix, framed in the big data environment for selecting individuals. Accordingly, we use an international sample of 2,675 large listed companies. The results show that the CUR leverage identifies greater consistency of the different aggregate measures of CSR, confirming its coherence with a correlation analysis. In this sense, it is possible to affirm that the composite indexes used in academia do not introduce any bias into the analysis of CSR practices. In addition, we demonstrate the utility of this technique to identify the most powerful companies, analysing their CSR commitment at the country and industry levels, namely, Norsk Hydro in the metal and mining industry in Norway, Stora Enso in forestry and paper in Finland, Akzo Nobel in chemical products in the Netherlands, BMW in automobiles and parts in Germany, Generali in finance in Italy, Novartis in pharmaceuticals in Switzerland, the BT Group in telecommunications in the United Kingdom and Inditex in textiles in Spain. Moreover, the results of the CUR study confirm that companies adapt to the demands or pressures from the stakeholders in different areas of interest, which are specific to each country and industry. The availability of these data allows the identification of the structural drivers of their growth and the establishment of priorities that allow the design of more effective sustainable development momentum policies.
On the existence and formation of small amplitude electrostatic double‐layer structure in nonthermal dusty plasma
Authors: Khan G. , Kumail Z. , Khan Y. , Ullah I. , Adnan M. 
Published: March 2020

AbstractIn the present article, we studied the effect of nonthermal electrons on the formation and existence of double‐layer structures in a three‐species plasma consisting of positive ions, nonthermal electrons, and immobile negative dust‐charged grains. Employing the reductive perturbations, a modified Korteweg–de Vries (mKdV) type equation is derived for the dust‐ion‐acoustic waves (DIAWs) bearing nonthermality. We found that both positive and negative polarity shock structures (double layer) can exist such that it switches polarity while changing the dust charge concentrations. However, strong nonthemality favours only rarefactive structures irrespective of the ion temperature. It is also found that increasing the nonthermal electron in the system the width of the double layer is increased; furthermore, the shock structure forms with small dust charge concentration. For small ionic temperature, increasing the nonthermal electrons in the system makes the double layer potential to increase; however, for σ = 1 reverse phenomena occurs. Our results are relevant to the shock observations in Q machine experiments and in the ionospheric regime of the earth.
Transport of N and P in U.S. streams and rivers differs with land use and between dissolved and particulate forms
Authors: Manning David W. P. , Rosemond Amy D. , Benstead Jonathan P. , Bumpers Phillip M. , Kominoski John S. 
Published: March 2020

AbstractWe used a recently published, open‐access data set of U.S. streamwater nitrogen (N) and phosphorus (P) concentrations to test whether watershed land use differentially influences N and P concentrations, including the relative availability of dissolved and particulate nutrient fractions. We tested the hypothesis that N and P concentrations and molar ratios in streams and rivers of the United States reflect differing nutrient inputs from three dominant land‐use types (agricultural, urban and forested). We also tested for differences between dissolved inorganic nutrients and suspended particulate nutrient fractions to infer sources and potential processing mechanisms across spatial and temporal scales. Observed total N and P concentrations often exceeded reported thresholds for structural changes to benthic algae (58, 57% of reported values, respectively), macroinvertebrates (39% for TN and TP), and fish (41, 37%, respectively). The majority of dissolved N and P concentrations exceeded threshold concentrations known to stimulate benthic algal growth (85, 87%, respectively), and organic matter breakdown rates (94, 58%, respectively). Concentrations of both N and P, and total and dissolved N:P ratios, were higher in streams and rivers with more agricultural and urban than forested land cover. The pattern of elevated nutrient concentrations with agricultural and urban land use was weaker for particulate fractions. The % N contained in particles decreased slightly with higher agriculture and urbanization, whereas % P in particles was unrelated to land use. Particulate N:P was relatively constant (interquartile range = 2–7) and independent of variation in DIN:DIP (interquartile range = 22–152). Dissolved, but not particulate, N:P ratios were temporally variable. Constant particulate N:P across steep DIN:DIP gradients in both space and time suggests that the stoichiometry of particulates across U.S. watersheds is most likely controlled either by external or by physicochemical instream factors, rather than by biological processing within streams. Our findings suggest that most U.S. streams and rivers have concentrations of N and P exceeding those considered protective of ecological integrity, retain dissolved N less efficiently than P, which is retained proportionally more in particles, and thus transport and export high N:P streamwater to downstream ecosystems on a continental scale.
Habits are stronger with longer duration of illness and greater severity in anorexia nervosa
Authors: Davis Lauren , Walsh B. Timothy , Schebendach Janet , Glasofer Deborah R. , Steinglass Joanna E. 
Published: March 2020

AbstractObjectiveThe aim of this study was to examine the relationship between habit strength and clinical features of anorexia nervosa (AN). Habit strength, separate from intention, relates to the persistence of behavior, and is measured by the Self‐Report Habit Index (SRHI). We hypothesized that habit strength would be greater among individuals with AN than healthy controls (HC) and that habit strength would be associated with duration and severity of illness.MethodParticipants were 116 women with AN (n = 69) and HC (n = 47) who completed the SRHI, the Eating Disorder Examination‐Questionnaire (EDE‐Q), and a multi‐item laboratory meal. The SRHI assessed four domains and these subscales were averaged for the total score.ResultsIndividuals with AN demonstrated significantly greater habit strength than HC in the total score (t114 = 7.00, p < .01), and within each domain (restrictive eating, compensatory behavior, delay of eating, and rituals). Total SRHI score was significantly associated with EDE‐Q scores for both AN and HC groups (rAN = .59, pAN = <.001; rHC = .32, pHC = .030). Among patients, there was a significant association between SRHI and duration of illness (r = .38, p = .001). There was no significant association between SRHI and caloric intake (rAN = −.20, pAN = .10; rHC = −.25, pHC = .09).DiscussionHabit strength was related to chronicity and severity of AN, suggesting that habit formation may play an important role in illness. These data suggest avenues for mechanism research and treatment development.