bluuebunny/crossref_metadata_2025 huggingface dataset:
Air‐Stable Low‐Symmetry Narrow‐Bandgap 2D Sulfide Niobium for Polarization Photodetection
Authors: Wang Yang , Wu Peisong , Wang Zhen , Luo Man , Zhong Fang , Ge Xun , Zhang Kun , Peng Meng , Ye Yan , Li Qing , Ge Haonan , Ye Jiafu , He Ting , Chen Yunfeng , Xu Tengfei , Yu Chenhui , Wang Yueming , Hu Zhigao , Zhou Xiaohao , Shan Chongxin , Long Mingsheng , Wang Peng , Zhou Peng , Hu Weida
Published: September 2020

Low‐symmetry 2D materials with unique anisotropic optical and optoelectronic characteristics have attracted a lot of interest in fundamental research and manufacturing of novel optoelectronic devices. Exploring new and low‐symmetry narrow‐bandgap 2D materials will be rewarding for the development of nanoelectronics and nano‐optoelectronics. Herein, sulfide niobium (NbS3), a novel transition metal trichalcogenide semiconductor with low‐symmetry structure, is introduced into a narrowband 2D material with strong anisotropic physical properties both experimentally and theoretically. The indirect bandgap of NbS3 with highly anisotropic band structures slowly decreases from 0.42 eV (monolayer) to 0.26 eV (bulk). Moreover, NbS3 Schottky photodetectors have excellent photoelectric performance, which enables fast photoresponse (11.6 µs), low specific noise current (4.6 × 10−25 A2 Hz−1), photoelectrical dichroic ratio (1.84) and high‐quality reflective polarization imaging (637 nm and 830 nm). A room‐temperature specific detectivity exceeding 107 Jones can be obtained at the wavelength of 3 µm. These excellent unique characteristics will make low‐symmetry narrow‐bandgap 2D materials become highly competitive candidates for future anisotropic optical investigations and mid‐infrared optoelectronic applications.
Spontaneously Formed Mott‐Schottky Electrocatalyst for Lithium‐Sulfur Batteries
Authors: Wang Yuankun , Zhang Ruifang , Sun Zehui , Wu Hu , Lu Shiyao , Wang Jianan , Yu Wei , Liu Jiamei , Gao Guoxin , Ding Shujiang
Published: September 2020

Developing effective electrocatalyst and deciphering its mechanism in modulating sulfur‐species‐conversion is still an important but challenging part for lithium sulfur (Li‐S) batteries. Here, a “spontaneous formed” strategy is presented to construct hierarchical CNT@ surface oxidized TiN nanoparticles (CNT@TiON) and the detailed interfaces mediation mechanism of Mott‐Schottky effect is disclosed on Li‐S chemistries. The results indicate the redistribution of local electron density in TiON is critical to enhancing the sulfur‐species utilization, lowering the energy barriers of intermediate step, and facilitating the conversion of PS. As a result, CNT@TiON‐S cathodes deliver significantly improved electrochemical performance, including low polarization, fleet reaction kinetics, and lasting cycle stability. This work embraces the local electronic state at heterojunction interface and paves a new way toward the design and understanding of efficient catalysts for Li‐S batteries.
Regeneration of β‐Cyclodextrin Based Membrane by Photodynamic Disulfide Exchange — Steroid Hormone Removal from Water
Authors: Dong Zheqin , Tagliavini Matteo , Darmadi Jason , Trouillet Vanessa , Schäfer Andrea I. , Levkin Pavel A.
Published: September 2020

The occurrence of steroid hormones in water and their serious impact on human and ecosystem demand high performance materials for efficient removal of such micropollutants. Here, an affinity membrane is developed for hormone removal with regenerable binding sites. By using photodynamic disulfides as a linker, UV induced detachment of β‐CD ligands from the membrane surface is demonstrated. The macroporous base membrane is first fabricated via a polymerization induced phase separation method using 2‐hydroxyethyl methacrylate (HEMA) and ethylene dimethylacrylate (EDMA) monomers. Then the affinity membranes are prepared by immobilizing β‐CD ligands to the poly(HEMA‐co‐EDMA) base membrane through the 2‐carboxyethyl disulfide linker. The β‐CD functionalized affinity membrane shows a 30% increase of E2 hormone uptake compared with the base membrane, attributed to the formation of CD‐hormone host–guest inclusion complexes. The photodynamic disulfide linkers enable UV‐induced detachment of blocked β‐CD ligands from and reattachment of fresh β‐CD ligands to the membrane surface after each adsorption cycle, thus conferring the affinity membrane with excellent regenerative properties. It is anticipated that the use of dynamic covalent bonds for binding ligands will be of interest for developing smart affinity membranes with regenerable and readjustable surface properties.
Interfacing Catalytic DNA with Nanomaterials
Authors: Moon Woohyun J. , Liu Juewen
Published: September 2020

DNAzymes are catalytic DNA strands with interesting features such as high stability, versatile activity, and programmability. Interfacing DNAzymes with nanomaterials has boosted their function to achieve biosensing, intracellular imaging, smart materials, cleavage of viral/cancer RNA, and enhancing substrate specificity. This review starts with the introduction of a few commonly used DNAzymes for RNA cleavage, DNA cleavage, and peroxidation. The interactions of DNA and DNAzymes with various inorganic surfaces including gold, metal oxides, carbon‐based nanomaterials, metal–organic frameworks, and hydrogels are then discussed. DNAzymes can be adsorbed, covalently linked, or entrapped in these nanomaterials. After that, representative examples of applications are reviewed with an emphasis on the DNA/nanomaterials’ interfaces and fundamental chemical interactions. These examples include using nanomaterials for adsorbing DNAzymes and fluorescence quenching, producing a color change, assisting DNAzymes entering cells, supplying extra metal ions, and for molecularly imprinting target molecules. Finally, some key challenges in the field are discussed, and future research opportunities addressing these challenges are proposed.
Organic Ligands Armored ZnO Enhances Efficiency and Stability of CsPbI2Br Perovskite Solar Cells
Authors: Wang Pang , Wang Hui , Mao Yuchao , Zhang Huijun , Ye Fanghao , Liu Dan , Wang Tao
Published: September 2020

Inorganic perovskite solar cells (PSCs) have witnessed great progress in recent years due to their superior thermal stability. As a representative, CsPbI2Br is attracting considerable attention as it can balance the high efficiency of CsPbI3 and the stability of CsPbBr3. However, most research employs doped charge transport materials or applies bilayer transport layers to obtain decent performance, which vastly complicates the fabrication process and scarcely satisfies the commercial production requirement. In this work, all‐layer‐doping‐free inorganic CsPbI2Br PSCs using organic ligands armored ZnO as the electron transport materials achieve an encouraging performance of 16.84%, which is one of the highest efficiencies among published works. Meanwhile, both the ZnO‐based CsPbI2Br film and device show superior photostability under continuous white light‐emitting diode illumination and improved thermal stability under 85 °C. The remarkable enhanced performance arises from the favorable organic ligands (acetate ions) residue in the ZnO film, which not only can conduce to maintain high crystallinity of perovskite, but also passivate traps at the interface through cesium/acetate interactions, thus suppressing the photo‐ and thermal‐ induced perovskite degradation.
Hexagonal BN‐Assisted Epitaxy of Strain Released GaN Films for True Green Light‐Emitting Diodes
Authors: Liu Fang , Yu Ye , Zhang Yuantao , Rong Xin , Wang Tao , Zheng Xiantong , Sheng Bowen , Yang Liuyun , Wei Jiaqi , Wang Xuepeng , Li Xianbin , Yang Xuelin , Xu Fujun , Qin Zhixin , Zhang Zhaohui , Shen Bo , Wang Xinqiang
Published: September 2020

Epitaxial growth of III‐nitrides on 2D materials enables the realization of flexible optoelectronic devices for next‐generation wearable applications. Unfortunately, it is difficult to obtain high‐quality III‐nitride epilayers on 2D materials such as hexagonal BN (h‐BN) due to different atom hybridizations. Here, the epitaxy of single‐crystalline GaN films on the chemically activated h‐BN/Al2O3 substrates is reported, paying attention to interface atomic configuration. It is found that chemical‐activated h‐BN provides BON and NO bonds, where the latter ones act as effective artificial dangling bonds for following GaN nucleation, leading to Ga‐polar GaN films with a flat surface. The h‐BN is also found to be effective in modifying the compressive strain in GaN film and thus improves indium incorporation during the growth of InGaN quantum wells, resulting in the achievement of pure green light‐emitting diodes. This work provides an effective way for III‐nitrides epitaxy on h‐BN and a possible route to overcome the epitaxial bottleneck of high indium content III‐nitride light‐emitting devices.
A Fully Aqueous Hybrid Electrolyte Rechargeable Battery with High Voltage and High Energy Density
Authors: Yuan Xinhai , Wu Xiongwei , Zeng Xian‐Xiang , Wang Faxing , Wang Jing , Zhu Yusong , Fu Lijun , Wu Yuping , Duan Xiangfeng
Published: September 2020

Aqueous rechargeable batteries (ARBs) offer advantages in terms of safety, environmental friendliness and cost over their non‐aqueous counterparts. However, the narrow electrochemical stability window of water inherently limits the output voltage and energy density of ARBs. Here, a system with an aqueous hybrid electrolyte containing a Zn anode in alkaline solution and LiMn2O4 cathode in neutral solution is reported. Combining the separated electrode‐electrolyte with a Li+‐conducting membrane, the potential window is effectively widened to enable an aqueous hybrid electrolyte rechargeable battery (AHERB) above 2.3 V. This battery system delivers a steady energy density of 208 Wh kg−1 (based on the total weight of active materials) at 1.69 C with a high average output voltage up to 2.31 V, cycled for over 1000 cycles with an average Coulombic efficiency of >98%.
Polymers for Battery Applications—Active Materials, Membranes, and Binders
Authors: Saal Adrian , Hagemann Tino , Schubert Ulrich S.
Published: September 2020

In the light of an ever‐increasing energy demand, the rising number of portable applications, the growing market of electric vehicles, and the necessity to store energy from renewable sources on large scale, there is an urgent need for suitable energy storage systems. In most batteries, the energy is stored by exploiting metals or metal‐ion‐based reactions. However, nearly every modern battery would not function without the help of polymers. Polymers fulfill several important tasks in battery cells. They are applied as binders for the electrode slurries, in separators and membranes, and as active materials, where charge is stored in organic moieties. This review concentrates on recent research on polymers utilized for every aspect of a battery, discussing state‐of‐the‐art lithium cells, current redox‐flow systems, and polymeric thin‐film batteries. The focus is on the properties of the polymers applied in different battery systems and how they affect their overall performance.
Highly Stable Pt‐Based Ternary Systems for Oxygen Reduction Reaction in Acidic Electrolytes
Authors: Kim Jun , Hong Yongju , Lee Kwangyeol , Kim Jin Young
Published: September 2020

In the era of the global rise of energy consumption and the accompanying environmental issues, energy production via fuel cells plays a vital role in a clean, secure, and affordable energy future. The development of Pt‐based binary alloy catalysts for the oxygen reduction reaction (ORR) has contributed significantly to the commercial realization of fuel cells, such as polymer electrolyte membrane fuel cells (PEMFCs) and phosphoric acid fuel cells (PAFCs). However, the short lifetime of the Pt‐based binary alloy catalyst remains a significant gap between lab‐scale and real‐device evaluation systems, calling for the development of catalysts that do not have stability issues. Among the various catalyst systems developed as alternatives to Pt‐based binary alloy catalysts, Pt‐based ternary systems with an additional element to the binary systems seem to provide the much‐awaited answer toward enhanced catalyst stability. Here, this progress report focuses on fundamental challenges of industrial fuel cell applications and provides broad and balanced insights on remarkable progress to date. Finally, it presents several perspectives on ideal ternary system design of efficient and robust Pt‐based electrocatalysts and guidance for future development beyond the academic level.
Tailoring the Cation Lattice for Chloride Lithium‐Ion Conductors
Authors: Liu Yunsheng , Wang Shuo , Nolan Adelaide M. , Ling Chen , Mo Yifei
Published: September 2020

All‐solid‐state Li‐ion batteries require Li‐ion conductors as solid electrolytes (SEs). Li‐containing halides are emerging as a promising class of lithium‐ion conductors with good electrochemical stability and other properties needed for SEs in all‐solid‐state batteries. Compared to oxides and sulfides, Li‐ion diffusion mechanisms in Li‐containing halides are less well understood, in particular regarding the effects of Li content and cation sublattices, which can be tailored for improving Li‐ion conduction. Using first‐principles computation, a systematic study is performed on the Li‐ion conduction of known Li‐containing chlorides with close‐packed anion frameworks and a wide range of their doped compounds. A dozen potential chloride Li‐ion conductors are predicted with increased Li‐ion conductivities, and it is revealed that the Li‐ion migration is greatly impacted by the cation configuration and concentrations. By analyzing a large set of materials data, it is proposed that low Li content, low cation concentration, and sparse cation distribution increase Li‐ion conduction in chlorides, and these principles are demonstrated in designing new chloride Li‐ion conductors. This study provides insights into the effects of the cation sublattice on Li‐ion diffusion, highlights potential chloride Li superionic conductors, and proposes design principles to further develop halide Li‐ion conductors.
High Voltage Stable Polyoxalate Catholyte with Cathode Coating for All‐Solid‐State Li‐Metal/NMC622 Batteries
Authors: Pan Xiangyu , Sun Han , Wang Zhaoxu , Huang Hao , Chang Qian , Li Junpeng , Gao Jian , Wang Shaofei , Xu Henghui , Li Yutao , Zhou Weidong
Published: September 2020

The solid polymer electrolyte (SPE) is one type of the most promising solid‐state electrolytes for next‐generation solid‐state batteries, due to its good compatibility with Li‐metal, high flexibility, and safety. To compete with currently used conventional Li‐ion batteries in energy density, SPEs must be integrated with high energy density cathode of LiNixMnyCozO2 (x + y + z = 1, 0.5 < x < 1) (NMC). However, the application of SPEs with NMC is limited by the narrow redox window of single SPEs and interfacial decomposition of SPEs by NMC. To overcome these challenges, a strategy is proposed utilizing a polymeric‐catholyte/‐anolyte‐composed dual‐polymer electrolyte and a cathode coating: a low voltage stable polyether works as a separator and stabilizes the interface with Li‐metal, while a high voltage stable polyoxalate functions as the catholyte and NMC particles are precoated by TiO2. This cell model not only widens the voltage window of the electrolyte system, but also protects the polyoxalate in the cathode from interfacial decomposition. With this strategy, cycling stability of all‐solid‐state Li‐metal/LiNi0.6Mn0.2Co0.2O2 (NMC622) cells is significantly improved. Meanwhile, large volume expansions of deposited lithium on both the Li‐metal anode and the copper collector are observed, which deserve more attention in the investigation of all‐solid‐state cells.
Surface Modification of Li‐Rich Mn‐Based Layered Oxide Cathodes: Challenges, Materials, Methods, and Characterization
Authors: Lei Yike , Ni Jie , Hu Zijun , Wang Ziming , Gui Fukang , Li Bing , Ming Pingwen , Zhang Cunman , Elias Yuval , Aurbach Doron , Xiao Qiangfeng
Published: September 2020

Rechargeable lithium‐ion batteries have become the dominant power sources for portable electronic devices, and are regarded as the battery technology of choice for electric vehicles and as potential candidates for grid‐scale storage. Commercial lithium‐ion batteries, after three decades of cell engineering, are approaching their energy density limits. Toward continually improving the energy density and reducing cost, Li‐rich Mn‐based layered oxide (LMLO) cathodes are receiving more and more attention due to their high discharge capacity and low cost. However, commercialization has been hampered by severe capacity and voltage decay, sluggish rate capability, and poor safety performance during charge/discharge cycles. Surface modification has effectively adopted to improve the electrochemical performance of LMLO cathodes. In this review, the main problems and recent progress in the field are summarized, focusing on challenges, materials, methods, and characterization techniques. More effective surface modification can be accomplished by strengthening nondestructive in situ measurements, expanding atomic/molecular layer (ALD/MLD) deposition techniques, and adopting fluorinated cosolvents.
Using a Dynamic Inhibition Concept to Achieve Content‐Controllable Synthesis of N‐Coordinated Cu Atoms as Reversible Active Site toward Super Li‐Ion Capacitors
Authors: Xue Yunyan , Li Yifan , Luo Guanwei , Shi Ke , Liu Enhao , Zhou Jisheng
Published: September 2020

Carbon‐supported single atomic metals (SAMs) have attracted great interest in energy research. However, it is still a great challenge to control the content of SAMs in carbon. In this work, a dynamic inhibition strategy is proposed to achieve content‐controllable synthesis of Cu atoms loaded in carbon nanofibers (CNFs) using polyacrylonitrile (PAN) and Cu(NO3)2 as precursors by electrospinning. Interestingly, N‐anchoring sites in PAN‐derived carbon matrix are dynamically increased to inhibit the aggregation of Cu atoms. Therefore, Cu atom content can be linearly controlled by adjusting the ratio of Cu(NO3)2/PAN, and a high mass content of 8.57 wt% can be achieved despite a low surface area of only 10 m2 g−1 for Cu‐doped CNFs. Atomic Cu is stabilized by N to form CuN3 coordination. More interestingly, N‐coordinated Cu atoms can not only improve the lithium‐ion diffusion kinetics in the CNFs, but also act as reversible Li storage sites. Therefore, Cu‐doped CNFs exhibit excellent rate and cycling performance for Li‐ion storage. Moreover, lithium‐ion capacitors, assembled by Cu‐doped CNFs as anode materials, can deliver high energy density (183.2 Wh kg−1) and high power density (11.0 kW kg−1). This concept opens up unique horizons for the design of SAMs toward new applications in energy storage.
What Water are We Really Pumping? The Nature and Extent of Surface and Groundwater Substitutability in Australia and Implications for Water Management Policies
Authors: Wheeler Sarah Ann , Zuo Alec , Kandulu John
Published: September 2020

Little is known about the interdependence between surface and groundwater extractions and trade. Groundwater metered extraction was modelled at the bore level (n = 1,890) in the Goulburn‐Murray Irrigation District, Victoria, from 2007–08 to 2016–17 to understand its associations with hydrologic, location, climatic, and economic factors. Surface and groundwater extractions were found to be substitutes for each other, with groundwater extractions statistically significantly increasing when: (i) bores were closer to surface water watercourses, (ii) surface water allocations and rainfall were lower, and (iii) surface water temporary market prices and entitlement trade out‐of‐zone volumes were higher. Other key groundwater extraction influences included pumping costs and commodity prices.
Virtual Mentoring: Two Adaptive Models for Supporting Early‐career Simulation Investigators in the Era of Social Distancing
Authors: Stapleton Stephanie N. , Wong Ambrose H. , Ray Jessica M. , Rider Ashley C. , Moadel Tiffany , Bentley Suzanne , Cassara Michael
Published: September 2020

Background

Early‐career simulation investigators identify limited mentorship as a common barrier to disseminating scholarship and launching a successful academic career in emergency medicine (EM). Conferences often bridge this gap, but the COVID‐19 pandemic has forced their indefinite delay. Virtual solutions are needed to capitalize on the breadth of national simulation research experts and grow mentorship in a postpandemic world.

Methods

We developed two complementary innovations to facilitate scholarship development and minimize COVID‐associated career challenges resulting from social distancing requirements. The e‐fellows forum (FF) provides a capstone experience for works‐in‐progress and the e‐consultation service (CS) supports simulation research during the earlier project stages of design and development. In conjunction with the Society for Academic Medicine’s Simulation Academy, we applied videoconferencing technology for both of these novel, virtual innovations. We analyzed corresponding chat transcripts and detailed field notes for emerging themes. In addition, we collected quantitative data via participant surveys regarding their experiences and impact on their projects.

Results

Nine simulation fellows presented at the FF and seven junior simulation investigators participated in the CS sessions. Most preferred the virtual format (56% FF, 66% CS) and found the sessions to be helpful in project advancement (66% FF, 100% CS). COVID‐19 affected most projects (89% FF, 67% CS). We identified three themes via qualitative analysis: design concerns and inquiries, validation or support shown by mentors and peers, and professional cohesion.

Conclusions

Participants felt that both virtual mentorship innovations advanced their simulation research projects and fostered a sense of professional cohesion within a greater community of practice. These benefits can be powerful at a time where simulation researchers in EM feel disconnected in an era of social distancing. Our future work will include adaptations to a hybrid model with both virtual and in‐person modalities as well as creation of more e‐mentorship opportunities, thus broadening the early‐career simulation research community of practice.
Benzobisoxazole Cruciforms: A Cross‐conjugated Platform for Designing Tunable Donor/Acceptor Materials
Authors: Burney‐Allen Alfred A. , Shaw Jessica , Wheeler David L. , Diodati Lily , Duzhko Volodimyr , Tomlinson Aimée L. , Jeffries‐EL Malika
Published: September 2020

Four cross‐conjugated molecules based on the benzo[1,2‐d:4,5‐d’]bisoxazole (BBO) moiety have been synthesized from a common synthon. Theoretical studies indicated that these cruciforms had highly segregated HOMO and LUMO levels enabling semi‐autonomous tuning of the LUMO level from the HOMO through substitution along the 2,6‐axis. The experimental data confirms that the HOMO levels within these systems varied by 0.3 eV, whereas the LUMO levels varied by over 1.6 eV when the electron‐density along the 2,6‐axis was increased. The introduction of relatively electron‐deficient moieties along the 2,6‐axis resulted in a bathochromic shift in the absorption profiles concurrent with the stabilization of the LUMO. These substituents also prolonged the photoluminescent lifetimes owing to improved intramolecular charge transfer states between the 4,8‐ and 2,6‐ axis. The BBO cruciforms were evaluated as donor materials in organic solar cells (OSC)s, but the energy‐level mismatches and poor thin film morphology led to poor performance. These results indicate that benzobisoxazole cruciforms are a promising platform for the development of tunable materials for use in organic semiconductors, but improvements in the optical, electronic and film‐forming properties are needed to enable their use in efficient OSCs.
How White nationalists mobilize genetics: From genetic ancestry and human biodiversity to counterscience and metapolitics
Authors: Panofsky Aaron , Dasgupta Kushan , Iturriaga Nicole
Published: September 2020

Objectives

Our aim in this study was to understand how genetics ideas are appropriated and mobilized online toward the political projects of White nationalism and the alt right. Studying three different online venues, we investigated how genetics is used to support racial realism, hereditarianism, and racial hierarchy. We analyzed how these ideas are connected to political and metapolitical projects. In addition, we examined the strategies used to build authority for these interpretations.

Methods

We analyze three online venues in which genetics has been mobilized to advance racial realism and hereditarian explanations of racial differences. These were (a) the use of genetic ancestry tests in online nationalist discussions, (b) blogs and other venues in which the human biodiversity ideas are articulated, (c) activities surrounding the OpenPsych collection of online journals. Ethnographic and interpretive methods were applied to investigate scientific and political meanings of efforts to mobilize genetic ideas.

Results

We found that White nationalists use genetic ancestry tests to align White identity with ideas of racial purity and diversity, educating each other about genetics, and debating the boundaries of Whiteness. “Human biodiversity” has been mobilized as a movement to catalog and create hereditarian ideas about racial differences and to distribute them as “red pills” to transform online discourse. The OpenPsych journals have allowed amateur hereditarian psychologists to publish papers, coordinate activity, and legitimate their project at the academic margins.

Conclusions

These various appropriations of genetics aim to further racial realism and hereditarian explanations of racial social and behavioral differences. Beyond these substantive aims, on a “metapolitical” level, they serve to reframe concepts and standards for political and scientific discussion of race, challenge structures of academic legitimacy and expertise, and build a cadre of ideological foot soldiers armed with an argumentative toolkit. As professional anthropologists and geneticists aim to accurately communicate their science and its implications for understanding human differences to the public, they must contend with these substantive claims and metapolitical contexts.
A Potent and Selective Janus Kinase Inhibitor with a Chiral 3D‐Shaped Triquinazine Ring System from Chemical Space
Authors: Meier Kris , Arús‐Pous Josep , Reymond Jean‐Louis
Published: September 2020

The generated databases (GDBs) enumerate billions of possible molecules following simple rules of chemical stability and synthetic feasibility. Exploring the GDBs shows that many chiral, 3D‐shaped ring systems, often containing quaternary centers, have never been exploited for drug design. Shown herein is that such ring systems can be useful for medicinal chemistry by using the example of the enantioselective synthesis of triquinazine, a novel chiral piperazine analogue derived from angular triquinane. It is used to design a nanomolar and selective inhibitor of Janus Kinase 1 and is related to the marketed drug Tofacitinib, which is useful for treating autoimmune diseases.
H2‐Free Re‐Based Catalytic Dehydroxylation of Aldaric Acid to Muconic and Adipic Acid Esters
Authors: Hočevar Brigita , Prašnikar Anže , Huš Matej , Grilc Miha , Likozar Blaž
Published: September 2020

As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid pre‐reduced catalyst was also investigated with hot‐filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H2) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 °C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures.
Salt to Taste: The Critical Roles Played by Inorganic Salts in Organozinc Formation and in the Negishi Reaction
Authors: Eckert Philip , Sharif Sepideh , Organ Michael G.
Published: September 2020

The first cross‐coupling of organozinc nucleophiles with aryl halides was reported in 1977 by Negishi. Unknown to all at the time was the importance of salt additives that were often present as a byproduct from the organozinc preparation. For decades, these salt additives were overlooked until 2006 when it was discovered that two different, yet effective methods for preparing organozinc solutions (i.e. one with salt and one without) provided drastically different results. Since this finding, the exact role of salt additives in cross‐coupling has been debated in the catalysis community. In this Review we highlight all the major discoveries regarding the influence of salt additives on the formation of organozinc reagents and their use in the Negishi reaction. These effects include solubilizing key intermediates, the formation of higher‐order zincates, product inhibition, catalyst protection, and solvent effects.
En Route Towards the Control of Luminescent, Optically‐Active 3D Architectures
Authors: Hindenberg Philip , Rominger Frank , Romero‐Nieto Carlos
Published: September 2020

π‐Extended systems are key components for the development of future organic electronic technologies. While conceiving molecules with improved properties is fundamental for the evolution of materials science, keeping control over the 3D arrangement of molecules represents an ever‐expanding challenge. Herein, a synthetic protocol to replace carbon atoms of π‐systems by dissymmetric phosphorus atoms is reported; in particular, it allowed for conceiving new fused phosphapyrene derivatives with improved properties. The presence of dissymmetric phosphorus atoms precluded the formation of excimers. X‐ray diffraction revealed that, meanwhile, strong intermolecular interactions are taking place in the solid state. The phosphapyrenes photoluminesce in the visible region with high quantum yields; importantly, they are CD‐active. In addition, the unique non‐planar features of phosphorus atoms allowed for the control of the 3D arrangement of molecules, rendering lemniscate‐like structures. Based on our discoveries, we envisage the possibility to construct higher‐order, chiral 3D architectures from larger phosphorus‐containing π‐systems.
Switching the Reactivity of Palladium Diimines with “Ancillary” Ligand to Select between Olefin Polymerization, Branching Regulation, or Olefin Isomerization
Authors: Jones Glen R. , Basbug Alhan Hatice E. , Karas Lucas J. , Wu Judy I. , Harth Eva
Published: September 2020

Coordinating solvents are commonly employed as ancillary ligands to stabilize late transition metal complexes and are conventionally considered to have little effect on the reaction products. Our work identifies that the presence of ancillary ligand in Pd‐diimine catalyzed polymerizations of α‐olefins can drastically alter reactivity. The addition of different amounts of acetonitrile allows for switching between distinct reaction modes: isomerization–polymerization with high branching (0 equiv.), regular chain‐walking polymerization (1 equiv.), and alkene isomerization with no polymerization (>20 equiv.). Optimization of the isomerization reaction mode led to a general set of conditions to switch a wide variety of diimine complexes into efficient alkene isomerization catalysts, with catalyst loading as low as 0.005 mol %.
A noninvasive and qualitative bioluminescent assay for express diagnostics of athletes' responses to physical exertion
Authors: Kratasyuk Valentina A. , Stepanova Lyudmila V. , Ranjan Rajeev , Sutormin Oleg S. , Pande Shubhra , Zhukova Galina V. , Miller Olga M. , Maznyak Natalya V. , Kolenchukova Oksana A.
Published: September 2020

Upcoming professional sports authorities seek rapid noninvasive biosensing tools for regular monitoring of athletes' physiological states. The analysis of saliva through luminescence‐based biosensors has been perceived as a suitable candidate for such purposes. The present study reports a qualitative bioluminescence assay based on a coupled enzyme system that consists of bacterial luciferase (BLuc) and nicotinamide adenine dinucleotide (NADH):flavin mononucleotide (FMN) oxidoreductase (Red), BLuc‐Red, for the express diagnostics of athletes' stress levels before and after physical exertion. The volunteers who participated in the study were grouped as freestyle wrestlers and students who adapted to different levels of physical activities. Under physical exertion modelling conditions, the influence of participant saliva on BLuc‐Red catalyzed light emission was investigated. Results showed a significant increase in residual luminescence (Iexp, mean maximum bioluminescence intensity of the experimental measurement (Iexp); Ic, luminescence intensity in control; Iexp/Ic, %) values for participants in the wrestler group while a decrease in the student group (P < 0.05). Such contrasting residual luminescence values in both groups were found to be dependent on the catalase activity of saliva. The proposed bioluminescence assay can be utilized as a potential nonspecific biosensing tool for determining the physical state of athletes under high loads.
Nanocomplex System of Bupivacaine with Dextran Sulfate for Parenteral Prolonged Delivery
Authors: Kim Hyung Tae , Park Jun Soo , Kang Myung Joo
Published: September 2020

An electrostatic complex system of bupivacaine (BUP), an amide‐type analgesic agent, with an oppositely charged polymer was designed for parenteral sustained delivery. The complex was prepared by admixing the drug (0.25–1.0% w/v) with different anionic polymers (dextran sulfate, carboxymethylcellulose, or carboxymethyl dextran, 1.0–5.0% w/v), and then adding calcium ion (0–1.0% w/v) as the noncovalent crosslinking agent. Negatively charged complexes ranging from 10 to 2000 nm were formed after the positively charged BUP molecules amalgamated with the polymers after gentle agitation. Drug released from the complex was markedly sustained either by increasing the polymer to drug ratio, or by increasing the calcium ion content. The optimized nanocomplex consisted of the drug, dextran sulfate, and calcium ion at the ratio of 1:20:20 w/w/w, which supplied a sustained release profile over 7 days. Therefore, novel nanocomplex is expected to be an effective tool to provide a sustained release of the analgesic agent.
Analyzing biological models and data sets using Jupyter notebooks as an alternate to laboratory‐based exercises during COVID‐19
Authors: Pillay Ché S.
Published: September 2020

Jupyter notebooks are widely used for data analysis across a large number of scientific disciplines. As a result of the COVID‐19 pandemic, I developed a series of computational exercises using the Jupyter notebook to replace the laboratory exercises usually undertaken in my course. My students had no prior coding knowledge and therefore these exercises were structured in a “cookbook” format using the susceptible‐infected‐resistant model for disease, data from the Lenski long‐term evolutionary experiment, and a fission yeast transcriptomic data set. Despite limited internet connectivity and on‐line instruction, my students completed these computational exercises and then tested their own hypotheses. Because Jupyter notebooks can be annotated with text and images, student notebooks were submitted for assessment in the form of a structured scientific report. An advantage of this approach was that all the computational analyses presented in these reports could be easily replicated. The notebook and complete instructions used in my course are provided for others who want to adopt this approach.
The position of the common facial vein in neonates: An alternate route for central venous catheter placement
Authors: van Tonder Daniël J. , Keough Natalie , van Niekerk Martin L. , van Schoor Albert N.
Published: September 2020

Introduction

We determine the location of the common facial vein (CFV) in a sample of neonates and assess the safety of this vein as an alternative access route for a central venous catheter (CVC).

Materials and Methods

We dissected both the left and right sides of the neck region in 24 neonatal, formalin‐fixed cadavers, exposing the underlying soft tissues and neurovascular structures. We identified the CFV, which we then pinned together with the internal jugular vein, cervical branch of facial nerve, marginal mandibular branch of the facial nerve, the cricoid cartilage, brachiocephalic vein, and the mastoid and sternal attachments of the sternocleidomastoid muscle. We measured the CFV and the related pinned structures.

Results

In neonates, the CFV intersected the anterior border of sternocleidomastoid on average 19.53 mm (left) and 21.73 mm (right) from its sternal attachment.

Conclusion

We found the CFV inferior to the upper one third and just superior to half of the length of the sternocleidomastoid muscle, indicating a possible “safe‐zone” where a skin incision could be made over the anteromedial border of sternocleidomastoid. The CFV is easily identified from surrounding landmarks. It could be used as a safe, alternative route for inserting a CVC if its average length (8.72 mm) and diameter (1.50 mm) are taken into account.
Development pattern of tracheal cartilage in human embryos
Authors: Fockens M. Matthijs , de Bakker Bernadette S. , Oostra Roelof‐Jan , Dikkers Frederik G.
Published: September 2020

Introduction

Congenital tracheal anomalies are associated with high morbidity and mortality. The etiology of congenital tracheal anomalies is not well understood, but often attributed to malformed tracheal cartilage. The development of tracheal cartilage has not been described in detail. In this study, we aimed to investigate the development pattern and timing of normal tracheal cartilage to better understand the etiology of tracheal anomalies.

Materials and methods

The development of tracheal cartilage was examined by studying the trachea in histological sections of 14 healthy human embryos from the Carnegie collection. Two specimens for Carnegie Stages 17–23 (42–60 days of embryological development) were studied.

Results

At Carnegie Stages 17–19 (42–51 days), a continuous mesenchymal condensation was observed ventral to the tracheal lumen. At Stages 20 and 21 (51–54 days), this pre‐tracheal mesenchyme showed sites of increased condensation indicative of future tracheal rings. Furthermore, growth centers were identified both proximally and distally in the trachea. Characteristic horseshoe shaped tracheal rings were apparent at Carnegie Stages 22 and 23 (54–60 days).

Conclusions

In human embryos, tracheal rings arise from growth centers in the ventral mesenchyme at approximately 51–54 days of embryological development. The observation of proximal and distal growth centers suggests a centripetal growth gradient, potentially contributing to occurrence of complete tracheal ring deformity (CTRD). Although this study shows new insights on tracheal cartilage development, the exact origin of congenital tracheal defects has yet to be elucidated.
A review of myocardial ischaemia/reperfusion injury: Pathophysiology, experimental models, biomarkers, genetics and pharmacological treatment
Authors: Gunata Mehmet , Parlakpinar Hakan
Published: September 2020

Cardiovascular diseases are known to be the most fatal diseases worldwide. Ischaemia/reperfusion (I/R) injury is at the centre of the pathology of the most common cardiovascular diseases. According to the World Health Organization estimates, ischaemic heart disease is the leading global cause of death, causing more than 9 million deaths in 2016. After cardiovascular events, thrombolysis, percutaneous transluminal coronary angioplasty or coronary bypass surgery are applied as treatment. However, after restoring coronary blood flow, myocardial I/R injury may occur. It is known that this damage occurs due to many pathophysiological mechanisms, especially increasing reactive oxygen types. Besides causing cardiomyocyte death through multiple mechanisms, it may be an important reason for affecting other cell types such as platelets, fibroblasts, endothelial and smooth muscle cells and immune cells. Also, polymorphonuclear leukocytes are associated with myocardial I/R damage during reperfusion. This damage may be insufficient in patients with co‐morbidity, as it is demonstrated that it can be prevented by various endogenous antioxidant systems. In this context, the resulting data suggest that optimal cardioprotection may require a combination of additional or synergistic multi‐target treatments. In this review, we discussed the pathophysiology, experimental models, biomarkers, treatment and its relationship with genetics in myocardial I/R injury.

Significance of the study

This review summarized current information on myocardial ischaemia/reperfusion injury (pathophysiology, experimental models, biomarkers, genetics and pharmacological therapy) for researchers and reveals guiding data for researchers, especially in the field of cardiovascular system and pharmacology.
Self‐organization Properties of a GPCR‐Binding Peptide with a Fluorinated Tail Studied by Fluorine NMR Spectroscopy
Authors: Jourdain de Muizon Capucine , Ramanoudjame Sridévi M. , Esteoulle Lucie , Ling Claude , Brou Germain , Anton Nicolas , Vandamme Thierry , Delsuc Marc‐André , Bonnet Dominique , Kieffer Bruno
Published: September 2020

Conjugation of the bioactive apelin‐17 peptide with a fluorocarbon chain results in self‐organization of the peptide into micelles. Fluorine NMR spectroscopy studies show that the fluoropeptide‘s micelles are monodisperse, while proton NMR indicates that the peptide moiety remains largely disordered despite micellization. A very fast exchange rate is measured between the free and micellar states of the peptide which enables the number of molecules present in the micelle to be estimated as 200, in agreement with values found by dynamic light scattering measurements.
Sustainable Dimethyl Carbonate Production from Ethylene Oxide and Methanol
Authors: Fallah Ramezani Saeed , Karimi Mehdi , Panahi Mehdi , Rafiee Ahmad
Published: September 2020

A large‐scale dimethyl carbonate (DMC) production process from ethylene oxide (EO), CO2, and methanol was simulated and optimized. Unlike most industrial processes of DMC production, the direct conversion of EO and CO2 to ethylene carbonate (EC) and EC transesterification to DMC were performed in a single reactor. The reaction volume and the reactor operating pressure were selected as decision variables and evaluated. The key performance parameters, e.g., conversion per pass and CO2 intensity, were compared with conventional commercialized routes or novel promising processes in the literature.
Tuning the Photo‐electrochemical Performance of RuII‐Sensitized Two‐Dimensional MoS2
Authors: Chen Xin , Krajewska Aleksandra M. , McGuinness Cormac , Lynes Amy , McAteer David , Berner Nina , Duesberg Georg , Coleman Jonathan N. , McDonald Aidan R.
Published: September 2020

Covalently tethering photosensitizers to catalytically active 1T‐MoS2 surfaces holds great promise for the solar‐driven hydrogen evolution reaction (HER). Herein, we report the preparation of two new RuII‐complex‐functionalized MoS2 hybrids [RuII(bpy)2(phen)]‐MoS2 and [RuII(bpy)2(py)Cl]‐MoS2. The influence of covalent functionalization of chemically exfoliated 1T‐MoS2 with coordinating ligands and RuII complexes on the HER activity and photo‐electrochemical performance of this dye‐sensitized system was studied systematically. We find that the photo‐electrochemical performance of this RuII‐complex‐sensitized MoS2 system is highly dependent on the surface extent of photosensitizers and the catalytic activity of functionalized MoS2. The latter was strongly affected by the number and the kind of functional groups. Our results underline the tunability of the photovoltage generation in this dye‐sensitized MoS2 system by manipulation of the surface functionalities, which provides a practical guidance for smart design of future dye‐sensitized MoS2 hydrogen production devices towards improved the photofuel conversion efficiency.
Quinoline Photobasicity: Investigation within Water‐Soluble Light‐Responsive Copolymers
Authors: Sittig Maria , Tom Jessica C. , Elter Johanna K. , Schacher Felix H. , Dietzek Benjamin
Published: September 2020

Quinoline photobases exhibit a distinctly higher pKa in their electronically excited state than in the ground state, thereby enabling light‐controlled proton transfer reactions, for example, in molecular catalysis. The absorption of UV light translates to a pKa jump of approximately 10 units, as established for small‐molecule photobases. This contribution presents the first synthesis of quinoline‐based polymeric photobases prepared by reversible addition‐fragmentation chain‐transfer (RAFT) polymerization. The integration of quinolines as photobase chromophores within copolymers offers new possibilities for light‐triggered proton transfer in nanostructured materials, that is, in nanoparticles, at surfaces, membranes and interfaces. To exploit the light‐triggered reactivity of photobases within such materials, we first investigated how the ground‐ and excited‐state properties of the quinoline unit changes upon polymer integration. To address this matter, we combined absorption and emission spectroscopy with time‐resolved transient‐absorption studies to reveal photoinduced proton‐transfer dynamics in various solvents. The results yield important insights into the thermodynamic and kinetic properties of these polymeric quinoline photobases.
Is smoking today more healthy?
Authors: Pansegrau Svenja , Busker Maike
Published: September 2020

Das Angebot zum Dampfen von E‐Zigaretten und zum Rauchen von Wasserpfeifen (Shishas) wird durch immer vielfältigere, fruchtige und süßliche Aromen sowie grelle, bunte Produkte geprägt. Laut dem Bundesinstitut für Risikobewertung (BfR) handelt es sich hierbei jedoch um keine unbedenklichen Produkte. Der Rauch einer Shisha enthält unter anderem hohe Mengen an Kohlenmonoxid sowie Teer. Der Dampf von E‐Zigaretten enthält unter anderem verschiedene gesundheitsschädliche Carbonylverbindungen, wie Formaldehyd. Insbesondere Jugendliche sind eine wichtige Zielgruppe der Tabakprävention. Daher bietet die Untersuchung von und die Diskussion über den Umgang mit Shishas, E‐Zigaretten und „normalen“ Tabakzigaretten im Chemieunterricht die Möglichkeit, Schülerinnen und Schüler früh für die eigene Gesundheit zu sensibilisieren und ihre Bewertungskompetenz zu schulen. Durch verschiedene quantitative und qualitative Experimente, die mit einfachen Mitteln im Schulunterricht eingesetzt und zur Diskussion gebracht werden können, lassen sich die verschiedenen Dampf‐ und Rauchsysteme experimentell untersuchen.