bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep‐Blue Thiophene‐Based Steric Oligomers as a Low‐Threshold Laser Gain and Host Material
Authors: Han Yamin , Bai Lubing , Xu Man , An Xiang , Wei Chuanxin , Sun Lili , Sun Ning , Yu Mengna , Zhang He , Lin Jinyi , Ou Changjin , Xie Linghai , Yin Chengrong , Sun Chen , Ding Xuehua , Cabanillas‐Gonzalez Juan , Huang Wei 
Published: April 2020

AbstractThiophene‐based (Th‐based) derivatives have received wide attentions in organic optoelectronics due to their excellent and tuneable optoelectrical properties as well as chemical modification. However, the low photoluminescence quantum yield in solid state limits their application in solution‐processed light‐emitting optoelectronic devices, especially in organic lasers. Herein, a novel blue‐emitting steric Th‐based fluorophore (MC8‐Th) with excellent optical gain behavior for organic laser is reported. Interestingly, MC8‐Th neat film exhibits efficient exceptional deep‐blue amplified spontaneous emission (ASE) behavior with a remarkably low threshold of 6.0 µJ cm−2 and full‐width‐at‐half‐maximum value of 2.6 nm. Furthermore, random laser signals are also obtained with the lowest threshold of 4.1 µJ cm−2 when incorporating the compound into an inert polystyrene (PS) matrix. In addition, low threshold (16 µJ cm−2, fivefold lower than those of F8BT neat films) yellow–green ASE emission (560 nm) is achieved through Förster resonance energy transfer. Meanwhile, ultrafast transient absorption spectroscopy is deployed here to observe the single‐molecular excitonic behavior in solution and PS‐blend, intermolecular excited state in neat film, and efficient energy transfer in MC8‐Th:F8BT‐blend films. As far as known, MC8‐Th shows lower threshold ASE/lasing behavior for the Th‐based conjugated materials.
Ru‐Catalyzed Carbonylative Murai Reaction: Directed C3‐Acylation of Biomass‐Derived 2‐Formyl Heteroaromatics
Authors: Sala Roberto , Roudesly Fares , Veiros Luis F. , Broggini Gianluigi , Oble Julie , Poli Giovanni 
Published: April 2020

AbstractThe Murai reaction is a ruthenium‐catalyzed transformation leading to alkylated arenes through the C−C bond formation between an alkene and an arene bearing a directing group. Discovered in the nineties, this useful C−H activation based coupling has been the object of intense study since its discovery. After having studied the Murai reaction on 2‐formylfurans of biomass derivation, we describe here the carbonylative version applied to 2‐formylfurans, 2‐formylpyrrols and 2‐formylthiophenes. This acylation reaction takes place regioselectively at C3 position of the heterocyclopentadienes thanks to the installation of removable imine directing groups. The transformation can be achieved by treating the two reaction partners with a catalytic amount of Ru3(CO)12, in toluene at 120–150 °C, after CO bubbling, at atmospheric pressure. DFT computations of the full catalytic cycle help in deciphering the mechanism of this transformation, and to rationalize the different behaviors depending on the nature of imine directing groups.magnified image
Water Solubilization of Phthalocyanine Derivatives via Interactions of Long Alkyl Chains and Cyclodextrins: Potential Complexes for Photodynamic Therapy
Authors: Goto Yuya , Hino Shodai , Sugikawa Kouta , Kawasaki Riku , Ikeda Atsushi 
Published: April 2020

AbstractFive types of cyclodextrins, based on α‐cyclodextrin (α‐CDx) and β‐cyclodextrin (β‐CDx), were used to make hydrophobic phthalocyanine (Pc) derivatives with long alkyl chains soluble in water via a high‐speed vibration milling method. Aqueous solutions of DMe‐β‐CDx‐based complexes were found to be the most stable, for at least 1 week over those containing α‐CDx. Although DMe‐β‐CDx complexes containing a free‐base Pc and Zn−Pc with eight dodecyl chains showed greater solubility than their α‐CDx‐base counterparts, α‐CDx complexes containing a free‐base Pc and Zn−Pc with eight dodecyl chains show no self‐aggregation of the Pcs and, as a result, exhibit fluorescence signals. Overall, it was found that the α‐CDx−Zn−Pc complex exhibits higher photodynamic activity than that of the commercially available and widely used photosensitizer Photofrin.
Valorization of whey using a biorefinery
Authors: Sebastián‐Nicolás Jessica L. , González‐Olivares Luis G. , Vázquez‐Rodríguez Gabriela A. , Lucho‐Constatino Carlos A. , Castañeda‐Ovando Araceli , Cruz‐Guerrero Alma E. 
Published: April 2020

AbstractIn Mexico, whey is discarded into drains without treatment, which represents an environmental problem. It is known that whey is a mixture of nutrients that increase biochemical demand (BOD) and chemical oxygen demand (COD), exceeding the limits established by national and international standards. Some uses of whey have been proposed to reduce the negative impact it produces on the environment. Some of these uses are the production of high‐value raw materials, separation of macromolecules of industrial interest, and the generation of energy, among others. The integral use of waste under a biorefinery scheme represents a viable alternative for the use of this waste. In this way, the chemical composition of the waste can be used to recover compounds with high added value. The main objective of this review is to propose a dairy whey biorefinery to use components of commercial interest. This biorefinery process involves three stages: the first is the separation of lactoferrin using a polyacrylamide matrix (PAM) impregnated with copper; the second is lactic fermentation using the residue resulting from the separation of lactoferrin, from which lactic acid, hydrolyzed proteins, and probiotics will be obtained. Finally, in the third stage, the residue from the previous stage can be used to generate biogas. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd
Evolutionary Views of Tuberculosis: Indoleamine 2,3‐Dioxygenase Catalyzed Nicotinamide Synthesis Reflects Shifts in Macrophage Metabolism
Authors: Suchard Melinda S. , Adu‐Gyamfi Clement G. , Cumming Bridgette M. , Savulescu Dana M. 
Published: April 2020

AbstractIndoleamine 2,3‐dioxygenase (IDO) is the rate‐limiting enzyme in conversion of tryptophan to kynurenines, feeding de novo nicotinamide synthesis. IDO orchestrates materno‐foetal tolerance, increasing human reproductive fitness. IDO mediates immune suppression through depletion of tryptophan required by T lymphocytes and other mechanisms. IDO is expressed by alternatively activated macrophages, suspected to play a key role in tuberculosis (TB) pathogenesis. Unlike its human host, Mycobacterium tuberculosis can synthesize tryptophan, suggesting possible benefit to the host from infection with the microbe. Intriguingly, nicotinamide analogues are used to treat TB. In reviewing this field, it is postulated that flux through the nicotinamide synthesis pathway reflects switching between aerobic glycolysis and oxidative phosphorylation in M. tuberculosis‐infected macrophages. The evolutionary cause of such shifts may be ancient mitochondrial behavior related to reproductive fitness. Evolutionary perspectives on the IDO pathway may elucidate why, after centuries of co‐existence with the Tubercle bacillus, humans still remain susceptible to TB disease.
Modeling the Residence Time Distribution of Integrated Continuous Bioprocesses
Authors: Sencar Jure , Hammerschmidt Nikolaus , Jungbauer Alois 
Published: April 2020

AbstractIn response to the biopharmaceutical industry advancing from traditional batch operation to continuous operation, the Food and Drug Administration (FDA) has published a draft for continuous integrated biomanufacturing. This draft outlines the most important rules for establishing continuous integration. One of these rules is a thorough understanding of mass flows in the process. A computer simulation framework is developed for modeling the residence time distribution (RTD) of integrated continuous downstream processes based on a unit‐by‐unit modeling approach in which unit operations are simulated one‐by‐one across the entire processing time, and then combined into an integrated RTD model. The framework allows for easy addition or replacement of new unit operations, as well as quick adjustment of process parameters during evaluation of the RTD model. With this RTD model, the start‐up phase to reach steady state can be accelerated, the effects of process disturbances at any stage of the process can be calculated, and virtual tracking of a section of the inlet material throughout the process is possible. A hypothetical biomanufacturing process for an antibody was chosen for showcasing the RTD modeling approach.
Artificial Metalloenzymes based on TetR Proteins and Cu(II) for Enantioselective Friedel‐Crafts Alkylation Reactions
Authors: Gutiérrez de Souza Cora , Bersellini Manuela , Roelfes Gerard 
Published: April 2020

AbstractThe supramolecular approach is among the most convenient methodologies for creating artificial metalloenzymes (ArMs). Usually this approach involves the binding of a transition metal ion complex to a biomolecular scaffold via its ligand, which also modulates the catalytic properties of the metal ion. Herein, we report ArMs based on the proteins CgmR, RamR and QacR from the TetR family of multidrug resistance regulators (MDRs) and Cu2+ ions, assembled without the need of a ligand. These ArMs catalyze the enantioselective vinylogous Friedel‐Crafts alkylation reaction with up to 75 % ee. Competition experiments with ethidium and rhodamine 6G confirm that the reactions occur in the chiral environment of the hydrophobic pocket. It is proposed that the Cu2+‐substrate complex is bound via a combination of electrostatic and π‐stacking interactions provided by the second coordination sphere. This approach constitutes a fast and straightforward way to assemble metalloenzymes and may facilitate future optimization of the protein scaffolds via mutagenesis or directed evolution approaches.
Self‐Organization in Electrochemical Synthesis as a Methodology towards New Materials
Authors: Pinto Maria R. , Costa Gabriel F. , Machado Eduardo G. , Nagao Raphael 
Published: April 2020

AbstractDespite its potential, self‐organization as a methodology for the synthesis of materials has not been developing at the pace required for the ample scale synthesis of materials with more complex structures. As there is an environmental demand for a fast change in the energy matrix, away from fossil fuels, by using materials with more complex composition and structure, this topic has been gaining potential. As complexity can be observed in many different fields of science, from biology to physical chemistry, this Review intends to focus on recent advances of self‐organization in electrochemical systems. To provide a deeper understanding of the literature being reviewed, the fundamentals of nonlinear dynamics in electrochemistry is discussed, based on classical literature. Following this, two electrochemical processes in which self‐organization is observed will be reviewed, namely electrodeposition and electrodissolution. In the final section, self‐organization is presented as a perspective for applied systems, where self‐organization is employed for the synthesis of materials of technological importance. This Review intends to reignite the debate on how self‐organization could be used to produce more complex materials than the traditional step‐by‐step approach could achieve.
Low‐Energy CO2 Reduction on a Metal‐Free Carbon Material
Authors: Xie Jiafang , Ghausi Muhammad Arsalan , Wang Jian , Wang Xueyuan , Wang Wei , Yang Rui , Wu Maoxiang , Zhang Qiaobao , Wang Yaobing 
Published: April 2020

AbstractElectrochemical CO2 reduction to value‐added chemicals on carbon‐based catalysts is a potential approach for low‐cost value‐added CO2 recycling. However, high overpotential and limited understanding of the mechanism remain challenging. Herein, a nitrogen and phosphorus co‐doped carbon (NPC) material, which is synthesized through a simple pyrolysis, promoted low‐energy electrochemical CO2 reduction. The NPC electrocatalyst combines the advantages of active sites co‐optimized by N and P, faster electrokinetics with bicarbonate providing proton, and more accessible active sites exposed by soft‐template precursors. The NPC electrocatalyst exhibited more than ten‐ and fourfold enhancement of the partial current density of CO production compared to N‐doped and P‐doped carbon materials, respectively, with high selectivity (86 % faradaic efficiency) at only −0.45 V. Experimental data coupled with density function theory calculations revealed that N and P dopants cooperated to enhance CO2 adsorption, first electron transfer to CO2 and then *COOH intermediate stabilization, leading to active and selective CO2‐to‐CO conversion. This work extends the design and understanding of metal‐free carbon‐based electrocatalysts for electrochemical CO2 reduction.
Hydrogen‐Atom Tunneling in Metaphosphorous Acid
Authors: Qian Weiyu , Chu Xianxu , Song Chao , Wu Zhuang , Jiao Mengqi , Liu Hanwen , Zou Bin , Rauhut Guntram , Tew David P. , Wang Lina , Zeng Xiaoqing 
Published: April 2020

AbstractMetaphosphorous acid (HOPO), a key intermediate in phosphorus chemistry, has been generated in syn‐ and anti‐conformations in the gas phase by high‐vacuum flash pyrolysis (HVFP) of a molecular precursor ethoxyphosphinidene oxide (EtOPO→C2H4+HOPO) at ca. 1000 K and subsequently trapped in an N2‐matrix at 2.8 K. Unlike the two conformers of the nitrogen analogue HONO, the anti‐conformer of HOPO undergoes spontaneous rotamerization at 2.8 K via hydrogen‐atom tunneling (HAT) with noticeable kinetic isotope effects for H/D (>104 for DOPO) and 16O/18O (1.19 for H18OPO and 1.06 for HOP18O) in N2‐matrices.
A Focus on Unusual ECL2 Interactions Yields β2‐Adrenergic Receptor Antagonists with Unprecedented Scaffolds
Authors: Scharf Magdalena M. , Zimmermann Mirjam , Wilhelm Florian , Stroe Raimond , Waldhoer Maria , Kolb Peter 
Published: April 2020

AbstractThe binding pockets of aminergic G protein‐coupled receptors are often targeted by drugs and virtual screening campaigns. In order to find ligands with unprecedented scaffolds for one of the best‐investigated receptors of this subfamily, the β2‐adrenergic receptor, we conducted a docking‐based screen insisting that molecules would address previously untargeted residues in extracellular loop 2. We here report the discovery of ligands with a previously undescribed coumaran‐based scaffold. Furthermore, we provide an analysis of the added value that X‐ray structures in different conformations deliver for such docking screens.
From 1 to 6: A Finer Analysis of Perturbed Branching Brownian Motion
Authors: Bovier Anton , Hartung Lisa 
Published: April 2020

AbstractThe logarithmic correction for the order of the maximum for two‐speed branching Brownian motion changes discontinuously when approaching slopes , which corresponds to standard branching Brownian motion. In this article we study this transition more closely by choosing and . We show that the logarithmic correction for the order of the maximum now smoothly interpolates between the correction in the i.i.d. case , and when . This is due to the localization of extremal particles at the time of speed change, which depends on α and differs from the one in standard branching Brownian motion. We also establish in all cases the asymptotic law of the maximum and characterize the extremal process, which turns out to coincide essentially with that of standard branching Brownian motion. © 2020 the Authors. Communications on Pure and Applied Mathematics published by Wiley Periodicals LLC
Probing DNA Dynamics: Stacking‐Induced Fluorescence Increase (SIFI) versus FRET
Authors: Morten Michael J. , Steinmark I. Emilie , Magennis Steven W. 
Published: April 2020

AbstractStacking‐induced fluorescence increase (SIFI) was introduced recently as a method to probe DNA structure and dynamics using only a single fluorescent label. Here we show that the same DNA hairpin dynamics can be recovered, at the single‐molecule level, using either SIFI (with Cy3 as the label) or FRET (with Cy3 as donor and Cy5 as acceptor). We also measured FRET using a donor that cannot undergo SIFI, Cy3B, in the presence and absence of a molecular crowding agent (PEG). Although crowding increases hairpin hybridisation to the same extent with either Cy3 or Cy3B as the donor, the absolute rates are affected by the choice of donor dye. This work shows that SIFI can be used to measure single‐molecule dynamics, which could offer advantages over FRET in some cases. It also illustrates how local dye interactions can influence biomolecular dynamics, which should be considered when designing experiments.
A Critical Evaluation of the Effect of Electrode Thickness and Side Reactions on Electrolytes for Aluminum–Sulfur Batteries
Authors: Lampkin John , Li He , Furness Liam , Raccichini Rinaldo , Garcia‐Araez Nuria 
Published: April 2020

AbstractThe high abundance and low cost of aluminum and sulfur make the Al–S battery an attractive combination. However, significant improvements in performance are required, and increasing the thickness and sulfur content of the sulfur electrodes is critical for the development of batteries with competitive specific energies. This work concerns the development of sulfur electrodes with the highest sulfur content (60 wt %) reported to date for an Al–S battery system and a systematic study of the effect of the sulfur electrode thickness on battery performance. If low‐cost electrolytes made from acetamide or urea are used, slow mass transport of the electrolyte species is identified as the main cause of the poor sulfur utilization when the electrode thickness is decreased, whereas complete sulfur utilization is achieved with a less viscous ionic liquid. In addition, the analysis of very thin electrodes reveals the occurrence of degradation reactions in the low‐cost electrolytes. The new analysis method is ideal for evaluating the stability and mass transport limitations of novel electrolytes for Al–S batteries.
Current Progress of Electrocatalysts for Ammonia Synthesis Through Electrochemical Nitrogen Reduction Under Ambient Conditions
Authors: Liu Anmin , Yang Yanan , Ren Xuefeng , Zhao Qidong , Gao Mengfan , Guan Weixin , Meng Fanning , Gao Liguo , Yang Qiyue , Liang Xingyou , Ma Tingli 
Published: April 2020

AbstractAmmonia, one of the most important chemicals and carbon‐free energy carriers, is mainly produced by the traditional Haber–Bosch process operated at high pressure and temperature, which results in massive energy consumption and CO2 emissions. Alternatively, the electrocatalytic nitrogen reduction reaction to synthesize NH3 under ambient conditions using renewable energy has recently attracted significant attention. However, the competing hydrogen evolution reaction (HER) significantly reduces the faradaic efficiency and NH3 production rate. The design of high‐performance electrocatalysts with the suppression of the HER for N2 reduction to NH3 under ambient conditions is a crucial consideration for the development of electrocatalytic NH3 synthesis with high FE and NH3 production rate. Five kinds of recently developed electrocatalysts classified by their chemical compositions are summarized, with particular emphasis on the relationship between their optimal electrocatalytic conditions and NH3 production performance. Conclusions and perspectives are provided for the future design of high‐performance electrocatalysts for electrocatalytic NH3 production. The Review can give practical guidance for the design of effective electrocatalysts with high FE and NH3 production rates.
Current Situation of the Challenging Scale‐Up Development of Hydroxymethylfurfural Production
Authors: Rosenfeld Catherine , Konnerth Johannes , Sailer‐Kronlachner Wilfried , Solt Pia , Rosenau Thomas , van Herwijnen Hendrikus W. G. 
Published: April 2020

AbstractHydroxymethylfurfural (HMF) is a high‐value platform chemical derived from renewable resources. In recent years, considerable efforts have been made to produce HMF also at industrial scale, which still faces some challenges regarding yield as well as sustainable and economic process designs. This critical Review evaluates the industrial process development of sustainable biomass conversion to HMF. Qualitative and quantitative guidelines are defined for the technological assessment of the processes described in patent literature. The formation of side products, difficulties in the separation and purification of HMF as well as catalyst regeneration were identified as major challenges in the HMF production. A first small‐scale, commercial HMF production plant with a capacity of 300 tHMF per year has been operating in Switzerland since 2014.
Ultrafast Carrier Transport through an Advanced Thick Electrode with a High Areal Capacity for Aqueous Lithium‐Ion Batteries
Authors: Chen Ying‐Chu , Hsu Yu‐Kuei 
Published: April 2020

AbstractThick electrode design holds great promise to render the aqueous lithium ion battery more cost effective by boosting the packing density of the electroactive materials to enhance the energy delivery at the device level. However, a thick electrode faces the concomitant challenge of the sluggish transport of electrons and, importantly, the Li ions. To address this issue, numerous 3 D shortcuts that include a conductive percolation network and well‐interconnected mesoporous channels were established in the 330 μm thick V2O5⋅H2O/CC monolithic electrode developed here. In this way, electron transfer and ion transport were favored, which accounts for the outstanding charge‐storage capacity that exceeded 2 mA h cm−2 and the exceptional energy and power densities of 1.38 mW h cm−2 and 34.1 mW cm−2, respectively, measured at the electrode and the device scale within a short subhour timeframe. Such a remarkable high rate performance is better than that of electrodes reported previously for commercial lithium‐ion microbatteries, advanced aqueous batteries, and state‐of‐the‐art supercapacitors designed for high‐power applications.
Recent Progress in Continuous‐Flow Hydrogenation
Authors: Yu Tao , Jiao Jiao , Song Peidong , Nie Wenzheng , Yi Chunhai , Zhang Qian , Li Pengfei 
Published: April 2020

AbstractTo achieve a safe, efficient, and sustainable (even fully automated) production for the continuous‐flow hydrogenation reactions, which is among the most often used reactions in chemical synthesis, new catalyst types and immobilization methods as well as flow reactors and technologies have been developed over the last years; in addition, these approaches have been combined with new and transformational technologies in other fields such as artificial intelligence. Thus, attention from academic and industry practitioners has increasingly focused on improving the performance of hydrogenation in flow mode by reducing the reaction times, increasing selectivities, and achieve safe operation. This Minireview aims to summarize the most recent research results on this topic with focus on the advantages, current limitations, and future directions of flow chemistry.
Energy relations of plasma waves in planar two‐dimensional electron‐ion plasmas
Authors: Moradi Afshin 
Published: April 2020

AbstractA derivation of the energy densities and power flows of plasma waves in a planar two‐dimensional electron‐ion plasma is presented through a simple approach. In this method, the response of an external current density introduced into the system is determined by a so‐called dispersion function. The advantage of the dispersion function is that it yields not only the dispersion relations of both plasmon (high‐frequency) and ion‐acoustic (low‐frequency) waves of the system, but expressions for the energy relations as
well.