bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Physical Origins of Charge Separation at Donor–Acceptor Interfaces in Organic Solar Cells: Energy Bending versus Energy Disorder
Authors: de Sousa Leonardo Evaristo , Coropceanu Veaceslav , da Silva Filho Demétrio Antônio , Sini Gjergji 
Published: January 2020

AbstractCharge separation (CS) is a central process in the working of organic solar cells (OSC). Despite the strong electron–hole (e–h) Coulombic attraction at the donor–acceptor (D–A) interface, the bound e–h pairs do separate into free charges following an ultrafast process. To explain these results, several models have been proposed. By means of kinetic Monte Carlo simulations, the energy bending (EB) at the D–A interface is considered as the driving force for CS against the impact of energy disorder. The results suggest that, while entropy and energy disorder alone allow for the bound e–h pairs to escape charger recombination, the efficiency of CS increases by several times and its timescale decreases significantly in the presence of EB, approaching experimental findings. The impact of external electric fields on CS efficiency is found to stem from insufficient amount of EB. Importantly, the results indicate that, in the absence of EB, simply improving charge carrier mobility in bulk has no effect on the performances of OSC, thus orienting the new materials design strategy toward preferably targeting interfacial properties. Guidelines regarding how to introduce EB at the D–A interface are also discussed.
A General and Practical Synthesis of Chiral 1,2‐Oxazetidines
Authors: Yang Jinggang , Wu Binyu , Hu Lin 
Published: January 2020

Abstract1,2‐Oxazetidines are valuable small strained molecules that could be used to create new and conventionally difficult‐to‐access chemical transformations. Currently, asymmetric methods towards this class of heterocycles are very rare. Herein, we report a general and practical method to access a series of structurally diverse chiral 1,2‐oxazetidines from readily available chiral epoxides and α‐bromo esters in 3–4 steps by using mild Mitsunobu reactions as an efficient ring‐closure approach to form the highly strained four‐membered rings. The new method is operationally simple, and a range of N‐nosyl‐protected 3‐ and 4‐substituted as well as 3,4‐disubstituted chiral 1,2‐oxazetidines could be conveniently prepared in gram‐scale with excellent enantioselectivities (93–99% ee) and good overall yields for the first time.
Metal–Organic Frameworks for the Exploitation of Distance between Active Sites in Efficient Photocatalysis
Authors: Gong Xuan , Shu Yufei , Jiang Zhuo , Lu Lingxiang , Xu Xiaohui , Wang Chao , Deng Hexiang 
Published: January 2020

AbstractDiscoveries of the accurate spatial arrangement of active sites in biological systems and cooperation between them for high catalytic efficiency are two major events in biology. However, precise tuning of these aspects is largely missing in the design of artificial catalysts. Here, a series of metal–organic frameworks (MOFs) were used, not only to overcome the limit of distance between active sites in bio‐systems, but also to unveil the critical role of this distance for efficient catalysis. A linear correlation was established between photocatalytic activity and the reciprocal of inter active‐site distance; a smaller distance led to higher activity. Vacancies created at selected crystallographic positions of MOFs promoted their photocatalytic efficiency. MOF‐525‐J33 with 15.6 Å inter active‐site distance and 33 % vacancies exhibited unprecedented high turnover frequency of 29.5 h−1 in visible‐light‐driven acceptorless dehydrogenation of tetrahydroquinoline at room temperature.
Enantioselective Total Synthesis of Macfarlandin C, a Spongian Diterpenoid Harboring a Concave‐Substituted cis‐Dioxabicyclo[3.3.0]octanone Fragment
Authors: Allred Tyler K. , Dieskau André P. , Zhao Peng , Lackner Gregory L. , Overman Larry E. 
Published: January 2020

AbstractThe enantioselective total synthesis of the rearranged spongian diterpenoid (−)‐macfarlandin C is reported. This is the first synthesis of a rearranged spongian diterpenoid in which the bulky hydrocarbon fragment is joined via a quaternary carbon to the highly hindered concave face of the cis‐2,8‐dioxabicyclo[3.3.0]octan‐3‐one moiety. The strategy involves a late‐stage fragment coupling between a tertiary carbon radical and an electrophilic butenolide resulting in the stereoselective formation of vicinal quaternary and tertiary stereocenters. A stereoselective Mukaiyama hydration that orients a pendant carboxymethyl side chain cis to the bulky octahydronapthalene substituent was pivotal in fashioning the challenging concave‐substituted cis‐dioxabicyclo[3.3.0]octanone fragment.
Intracellular Electrochemical Nanomeasurements Reveal that Exocytosis of Molecules at Living Neurons is Subquantal and Complex
Authors: Larsson Anna , Majdi Soodabeh , Oleinick Alexander , Svir Irina , Dunevall Johan , Amatore Christian , Ewing Andrew G. 
Published: January 2020

AbstractSince the early work of Bernard Katz, the process of cellular chemical communication through exocytosis, quantal release, has been considered to be all or none. Recent evidence has shown exocytosis to be partial or “subquantal” at single‐cell model systems, but there is a need to understand this at communicating nerve cells. Partial release allows nerve cells to control the signal at the site of release during individual events, for which the smaller the fraction released, the greater the range of regulation. Herein, we show that the fraction of the vesicular octopamine content released from a living Drosophila larval neuromuscular neuron is very small. The percentage of released molecules was found to be only 4.5 % for simple events and 10.7 % for complex (i.e., oscillating or flickering) events. This large content, combined with partial release controlled by fluctuations of the fusion pore, offers presynaptic plasticity that can be widely regulated.
Asymmetric Three‐Component Heck Arylation/Amination of Nonconjugated Cyclodienes
Authors: Zhu Daoyong , Jiao Zhiwei , Chi Yonggui Robin , Gonçalves Théo P. , Huang Kuo‐Wei , Zhou Jianrong Steve 
Published: January 2020

AbstractSubstituted cyclohexylamines are becoming increasingly important in drug discovery. Asymmetric Heck insertion/amination of nonconjugated cyclodienes proceeds to give 5‐aryl cyclohexenylamines with good enantioselectivity and exclusive trans configurations. Primary and secondary anilines, indoline, and benzylamines are suitable amines. The weakly donating diphosphite Kelliphite forms a deep unsymmetrical pocket, which is essential for stereoselective anti attack of amines.
Unveiling the Activity Origin of a Copper‐based Electrocatalyst for Selective Nitrate Reduction to Ammonia
Authors: Wang Yuting , Zhou Wei , Jia Ranran , Yu Yifu , Zhang Bin 
Published: January 2020

AbstractUnveiling the active phase of catalytic materials under reaction conditions is important for the construction of efficient electrocatalysts for selective nitrate reduction to ammonia. The origin of the prominent activity enhancement for CuO (Faradaic efficiency: 95.8 %, Selectivity: 81.2 %) toward selective nitrate electroreduction to ammonia was probed. 15N isotope labeling experiments showed that ammonia originated from nitrate reduction. 1H NMR spectroscopy and colorimetric methods were performed to quantify ammonia. In situ Raman and ex situ experiments revealed that CuO was electrochemically converted into Cu/Cu2O, which serves as an active phase. The combined results of online differential electrochemical mass spectrometry (DEMS) and DFT calculations demonstrated that the electron transfer from Cu2O to Cu at the interface could facilitate the formation of *NOH intermediate and suppress the hydrogen evolution reaction, leading to high selectivity and Faradaic efficiency.
Thermal Degradation of p‐Hydroxybenzoic Acid in Macadamia Nut Oil, Olive Oil, and Corn Oil
Authors: Castada Hardy Z. , Sun Zhaoyu , Barringer Sheryl A. , Huang Xuesong 
Published: January 2020

Abstractp‐Hydroxybenzoic acid (PHBA) plays a significant role in sustaining the oxidative stability of macadamia nut oil (MNO). However, PHBA undergoes thermal decarboxylation and loses its bioactive antioxidant properties. In this study, we determine PHBA degradation kinetics in oils at various heating temperatures, which provides fundamental understanding of PHBA thermal degradation in oils and oil quality changes during high‐temperature processing. PHBA degradation kinetics in MNO, olive oil, and corn oil were evaluated at temperatures typical for cooking and frying. PBHA headspace concentration was measured using selected ion flow tube mass spectrometry. PHBA decarboxylation followed a zero‐order reaction, where degradation could be affected by factors such as the type of oil matrix having different FA compositions, antioxidants, and component interactions. PHBA degradation activation energies (E
a) showed that PHBA was more stable against thermal decarboxylation in MNO (85 kJ mol–1) than in olive oil (40 kJ mol−1) or corn oil (22 kJ mol−1). The higher enthalpy () of decarboxylation in MNO (82 kJ mol−1) indicates that PHBA is more inhibited from decomposition than olive oil (37 kJ mol−1) or corn oil (19 kJ mol−1). Moreover, the negative entropy values () of PHBA degradation from MNO (−192 J mol−1 K−1), olive oil (−277 J mol−1 K−1), and corn oil (−325 J mol−1 K−1) indicates that these oils impart some inhibitory properties against PHBA thermal decarboxylation.
Zeolite imidazolate framework (ZIF)‐based mixed matrix membranes for CO2 separation: A review
Authors: Guan Weixin , Dai Yan , Dong Chenyuan , Yang Xiaochen , Xi Yuan 
Published: January 2020

ABSTRACTMixed matrix membranes (MMMs), which combine the good separation performance of inorganic materials with the low cost of polymers, have emerged as a research hotspot for gas separation membranes. Zeolite imidazolate frameworks (ZIFs) are widely used as fillers to prepare MMMs owing to their advantageous characteristics, such as adjustable pore channels, unsaturated sites, and easy functionalization. For MMMs, three directions can be employed as criteria for improvement compared with pristine polymeric membranes. In this article, the progress of ZIF‐based MMMs is reviewed from the aspects of sole‐ZIF‐based MMMs and modified ZIF‐based MMMs. Both strategies improve the separation performance through different improvement directions and mechanisms. Our analysis shows that the synergistic effect of the modified filler can change the structure of the membranes, such as by improving the filler–polymer interface voids, which provides a foundation to overcome the trade‐off effect to a certain extent. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48968.
Influence of pre‐electrophoresis on protein separations in polyacrylamide gels
Authors: Haris Anfal , Sanders Jonathan R. , Arce Pedro E. 
Published: January 2020

AbstractPolyacrylamide gel electrophoresis (PAGE) is a widely used technique in protein separations. In this study, the effects of pre‐electrophoresis (i.e., exposing polyacrylamide gels to an electrical field prior to loading samples) on the separation of a mixture of 10 standard proteins was investigated. Three different gel concentrations (based on amounts of acrylamide and bis‐acrylamide, always at a 37.5:1 ratio) relative to the volume of the gel solution were tested: 6%, 9%, and 12%. For each concentration, multiple slab gels were subjected to pre‐electrophoresis prior to separation of proteins, while multiple other (i.e., companion) slab gels were used but without applying the pre‐electrophoresis technique. Separation results were investigated, showing that the application of the pre‐electrophoresis technique had a significant effect on separations particularly for 6% and 9% gels.
Optimization of dosing and mixing time through fabrication of high internal phase emulsion (HIPE) polymerization based adsorbents for use in purification of oil in water contaminated wastewater
Authors: Soliman Ahmed G. , El Naggar Ahmed M.A. , El‐Din Mahmoud R. Noor , Ramadan Ahmed M. , Youssef Mohamed A. 
Published: January 2020

AbstractDisposal of oil‐contaminated wastewater is associated with serious environmental problems since it is drained in seawater or into the ground. These routes of disposal can dangerously affect the lives of both humans and aqua creatures. Therefore, this research study introduces the recovery of petroleum wastewater through the usage of polystyrene‐based adsorbents. High internal phase emulsion polymerization was the used methodology to provide the introduced structures where new approaches have been presented. Unlike the common, the influence of the fabrication parameters of polymeric adsorbents on the oil removal has been investigated. Particularly, different dosing and mixing times were utilized during the preparation stage. Their effect on the polymers surface properties and molecular weights were traced. The obtained adsorbents were subjected to the oil removal stage where optimization of synthesis conditions was taken place. Nearly 92% of the oil content (80 ppm) in the wastewater was removed using the optimized adsorbent. This adsorbent showed surface area of 28.8 m2/g and molecular weight equal 279,970 g/mol. It was acquired by applying 20 min as a dosing time and reaction time of 120 min.
Synthesis, in‐vitro and in‐silico study of novel thiazoles as potent antibacterial agents and MurB inhibitors
Authors: Sanad Sherif M. H. , Ahmed Ahmed A. M. , Mekky Ahmed E. M. 
Published: January 2020

AbstractEfficient procedures are herein reported for the synthesis of novel hybrid thiazoles via a one‐pot three‐component protocol. The protocol involves the reaction of novel aldehyde, thiosemicarbazide and halogen‐containing reagents in solvent‐ and catalyst‐free conditions. The structures of the new thiazoles were elucidated by elemental analyses and spectroscopic data. The in‐vitro antibacterial screening and MurB enzyme inhibition assays were performed for the novel thiazoles. The thiazol‐4(5H)‐one derivative 6d, with p‐MeO, exhibits the best antibacterial activities with minimum inhibitory concentration values of 3.9, 3.9, 7.8, and 15.6 μg/ml against Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus mutans, and Escherichia coli, respectively, as compared to the reference antibiotic drugs. It also exhibits the highest inhibition of the MurB enzyme with an IC50 of 8.1 μM. The structure–activity relationship was studied to determine the effect of the structures of the newly prepared molecules on the strength of the antibacterial activities. Molecular docking was also performed to predict the binding modes of the new thiazoles in the active sites of the E. coli MurB enzyme.
Female librarians and male computer programmers? Gender bias in occupational images on digital media platforms
Authors: Singh Vivek K. , Chayko Mary , Inamdar Raj , Floegel Diana 
Published: January 2020

AbstractMedia platforms, technological systems, and search engines act as conduits and gatekeepers for all kinds of information. They often influence, reflect, and reinforce gender stereotypes, including those that represent occupations. This study examines the prevalence of gender stereotypes on digital media platforms and considers how human efforts to create and curate messages directly may impact these stereotypes. While gender stereotyping in social media and algorithms has received some examination in the recent literature, its prevalence in different types of platforms (for example, wiki vs. news vs. social network) and under differing conditions (for example, degrees of human‐ and machine‐led content creation and curation) has yet to be studied. This research explores the extent to which stereotypes of certain strongly gendered professions (librarian, nurse, computer programmer, civil engineer) persist and may vary across digital platforms (Twitter, the New York Times online, Wikipedia, and Shutterstock). The results suggest that gender stereotypes are most likely to be challenged when human beings act directly to create and curate content in digital platforms, and that highly algorithmic approaches for curation showed little inclination towards breaking stereotypes. Implications for the more inclusive design and use of digital media platforms, particularly with regard to mediated occupational messaging, are discussed.
Multilingual publishing in the social sciences and humanities: A seven‐country European study
Authors: Kulczycki Emanuel , Guns Raf , Pölönen Janne , Engels Tim C. E. , Rozkosz Ewa A. , Zuccala Alesia A. , Bruun Kasper , Eskola Olli , Starčič Andreja Istenič , Petr Michal , Sivertsen Gunnar 
Published: January 2020

AbstractWe investigate the state of multilingualism across the social sciences and humanities (SSH) using a comprehensive data set of research outputs from seven European countries (Czech Republic, Denmark, Finland, Flanders [Belgium], Norway, Poland, and Slovenia). Although English tends to be the dominant language of science, SSH researchers often produce culturally and societally relevant work in their local languages. We collected and analyzed a set of 164,218 peer‐reviewed journal articles (produced by 51,063 researchers from 2013 to 2015) and found that multilingualism is prevalent despite geographical location and field. Among the researchers who published at least three journal articles during this time period, over one‐third from the various countries had written their work in at least two languages. The highest share of researchers who published in only one language were from Flanders (80.9%), whereas the lowest shares were from Slovenia (57.2%) and Poland (59.3%). Our findings show that multilingual publishing is an ongoing practice in many SSH research fields regardless of geographical location, political situation, and/or historical heritage. Here we argue that research is international, but multilingual publishing keeps locally relevant research alive with the added potential for creating impact.
High Energy Li‐Ion Electrodes Prepared via a Solventless Melt Process
Authors: Astafyeva Ksenia , Dousset Capucine , Bureau Yannick , Stalmach Sara‐Lyne , Dufour Bruno 
Published: January 2020

AbstractHigh areal density and high energy Li‐ion electrodes were prepared using a high throughput green, solventless and inexpensive melt process leading to electrodes of controlled porosity. Melt formulations were developed for NCA cathodes and graphite anodes. The formulations were based on commercially available and inexpensive elastomeric or thermoplastic binders, conventional conducting fillers and >90 wt% electrode active materials. A large range of loadings could be achieved, from 4 to 40 mg cm−2 single side. Electrochemical performances in half cells (coin cells) are reported. High capacity and cyclability for high loadings of NCA cathodes and graphite anodes were demonstrated. Areal capacities over 5 mAh.cm−2 in coin cells were obtained at a C/5 rate. Cycling at high rates, up to 5 C was demonstrated.
Ric‐8A, a GEF, and a Chaperone for G Protein α‐Subunits: Evidence for the Two‐Faced Interface
Authors: Srivastava Dhiraj , Artemyev Nikolai O. 
Published: January 2020

AbstractResistance to inhibitors of cholinesterase 8A (Ric‐8A) is a prominent non‐receptor GEF and a chaperone of G protein α‐subunits (Gα). Recent studies shed light on the structure of Ric‐8A, providing insights into the mechanisms underlying its interaction with Gα. Ric‐8A is composed of a core armadillo‐like domain and a flexible C‐terminal tail. Interaction of a conserved concave surface of its core domain with the Gα C‐terminus appears to mediate formation of the initial Ric‐8A/GαGDP intermediate, followed by the formation of a stable nucleotide‐free complex. The latter event involves a large‐scale dislocation of the Gα α5‐helix that produces an extensive primary interface and disrupts the nucleotide‐binding site of Gα. The distal portion of the C‐terminal tail of Ric‐8A forms a smaller secondary interface, which ostensibly binds the switch II region of Gα, facilitating binding of GTP. The two‐site Gα interface of Ric‐8A is distinct from that of GPCRs, and might have evolved to support the chaperone function of Ric‐8A.
Endothelium capture-based liver segment imaging using vascular endothelial growth factor receptor 2 in preclinical ex vivo models
Authors: Kyuno D , Qian B , Groß W , Schäfer M , Ryschich E 
Published: January 2020

Abstract

Background
Near-infrared (NIR) imaging of liver segments provides substantial information for surgeons performing liver resection. It was hypothesized that ramucirumab, an endothelium-specific antibody approved by the Food and Drug Administration, could be used for liver segment imaging using the endothelium capture principle.

Methods
The capture efficacy of anti-vascular endothelial growth factor receptor (VEGFR) 2 monoclonal antibodies (mAbs) and segment imaging were studied in a mouse model. Binding of ramucirumab in human and porcine tissues was studied using immunofluorescence staining. Isolated porcine liver perfusion was used to analyse the labelling and NIR imaging of selected liver segments.

Results
VEGFR2 is well expressed on the endothelium of the smallest microvascular blood vessels in mouse, porcine and human liver tissues, as well as in human liver tumours. Perfusion of selected segments in the isolated liver model showed high capture of the anti-VEGFR2 (clone 522302) mAb and ramucirumab in mice and pigs respectively. NIR imaging of selected segments was achieved using isolated porcine liver perfusion with IRDye® 800CW-conjugated ramucirumab.

Conclusion
VEGFR2 is well expressed on the smallest microvascular blood vessels and can capture antibodies during single intravascular passages with high efficacy. The ex vivo imaging of a selected segment using endothelial capture of ramucirumab demonstrates the potential of this antibody for intraoperative navigation in liver surgery. Surgical relevanceImaging of liver segments provides substantial information for surgeons when performing liver resection.The antivascular endothelial growth factor receptor (VEGFR) 2 antibody ramucirumab conjugated with near-infrared dye could visualize selected liver segments using an endothelial capture-based approach in an isolated perfusion liver model.The ex vivo imaging of a selected segment using endothelial capture of ramucirumab demonstrates the potential of this anti-VEGFR2 antibody for intraoperative navigation in liver surgery.