bluuebunny/crossref_metadata_2025_split huggingface dataset:
The adipokinetic hormones and their cognate receptor from the desert locust, Schistocerca gregaria: solution structure of agonists and model of their binding to the receptor
Authors: Jackson Graham Ellis , Pavadai Elumalai , Gäde Gerd , Andersen Neils 
Published: April 2019

Background. Neuropeptides exert their activity through binding to G-protein coupled receptors (GPCRs). GPCRs are well-known drug targets in the pharmaceutical industry and are currently discussed as targets to control pest insects. Here we investigate the neuropeptide adipokinetic hormone (AKH) system of the desert locust Schistocerca gregaria. The desert locust is known for its high reproduction, and for forming devastating swarms consisting of billions of individual insects. It is also known that S. gregaria produces three different AKHs as ligands but has only one AKH receptor. The AKH system is known to be essential for metabolic regulation, which is necessary for reproduction and flight activity.
Methods. Nuclear magnetic resonance techniques (NMR) in a dodecylphosphocholin (DPC) micelle solution were used to determine the structure of the three AKHs. The primary sequence of the S. gregaria AKH receptor (AKHR) was used to construct a 3D molecular model. Next, the 3 AKHs were individually docked to the receptor, and dynamic simulation of the whole ligand-receptor complex in a model membrane was performed.
Results. Although the three endogenous AKHs of S. gregaria have quite different amino acids sequences and chain length (two octa- and one decapeptide), NMR experiments assigned a turn structure in DPC micelle solution for all. The GPCR-ModSim program identified human kappa opioid receptor (hk-OR) to be the best template after which the S. gregaria AKHR was modeled. All three AKHs were found to have the same binding site on this receptor, interact with similar residues of the receptor and have comparable binding constants. Molecular switches were also identified; the movement of the receptor could be visually shown when ligands (AKHs) were docked and the receptor was activated.
Conclusions. The study proposes a model of binding of the three endogenous ligands to the one existing AKH receptor in the desert locust and paves the way to use such a model for the design of peptide analogs and finally, peptide mimetics, in the search for novel species-specific insecticides based on receptor-ligand interaction.
In vitro Antimicrobial and Antifungal Efficacy of Ethanol Crude Stem Bark Extract of Boswella dalzielle
Authors: Ogbu K. I. , Chukwudi I. C. , Ijomanta O. J. , Agwu E. O. , Chinonye C. N. , Kespo K. B. 
Published: April 2019

The efficacy of Boswellia dalzielii (Frankincense) stem bark extract on some bacterial and fungal organisms was evaluated for its in-vitro antimicrobial activities against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Salmonella gallinarium, Aspergillus fumigatus and Candida albicans. The research work was carried out in Biochemistry and Microbiology Laboratories of Federal College of Animal Health and Production Technology, National Veterinary Research Institute, Vom. Well diffusion method was carried out on nutrient agar. MIC, MBC and MFC of the test organisms were carried out on nutrient broth. The phytochemistry revealed the presence of saponin, tannin, flavonoids, cardiac glycosides, steroids, terpens and phenol in ethanol extracts while resin, alkaloid and glycosides were absent in hot water extracts. Alkaloid was also absent in ethanolic extract. The aqueous extract of the plant exhibited neither antibacterial nor antifungal effects against all test organisms used in the study while the ethanolic extract of the plant showed both antibacterial and antifungal effects on the study organisms. The results of this study also showed that the ethanolic extract of Boswellia dalzielii stem bark has activity against all bacteria species used in the study (broad spectrum activity). For gram-negative and positive bacteria, Salmonella gallinarium and Staphylococcus aureus were the most sensitive while Escherichia coli and Streptococcus pyogenes were the least respectively. Candida albicans was more sensitive than Aspergillus fumigatus. It was concluded that the test organisms were susceptible to ethanol extracts of the plant and may be good source of antibiotics.
Programmable Functionalization of Surfactant‐Stabilized Microfluidic Droplets via DNA‐Tags
Authors: Jahnke Kevin , Weiss Marian , Frey Christoph , Antona Silvia , Janiesch Jan‐Willi , Platzman Ilia , Göpfrich Kerstin , Spatz Joachim P. 
Published: April 2019

AbstractDroplet‐based microfluidics has emerged as a powerful tool in synthetic biology. For many applications, chemical functionalization of the droplets is a key process. Therefore, a straightforward and broadly applicable approach is developed to functionalize the inner periphery of microfluidic droplets with diverse reactive groups and components. Instead of covalent modification of the droplet‐stabilizing surfactants, this method relies on cholesterol‐tagged DNA that self‐assembles at the droplet periphery. The cholesterol‐tagged DNA serves as an attachment handle for the recruitment of complementary DNA. The complementary DNA can carry diverse functional groups. We exemplify our method by demonstrating the attachment of amine groups, DNA nanostructures, microspheres, a minimal actin cortex, and leukemia cells to the droplet periphery. It is further shown that the DNA‐mediated attachment to the droplet periphery is temperature‐responsive and reversible. It is envisioned that droplet functionalization via DNA handles will help to tailor droplet interfaces for diverse applications—featuring programmable assembly, unique addressability, and stimuli‐responsiveness.
Reversibly and Irreversibly Humidity‐Responsive Motion of Liquid Crystalline Network Gated by SO2 Gas
Authors: Lan Ruochen , Sun Jian , Shen Chen , Huang Rui , Zhang Lanying , Yang Huai 
Published: April 2019

AbstractManipulating functional liquid crystalline networks (LCNs) by multiple stimuli has been a hot topic in the research of smart actuators and fabrication of biomimetic robots. Here, a single‐layer LCN film showing dual responsiveness to humidity and SO2 gas is prepared. Interestingly, the humidity sensitivity of the LCN film can be gated by exposing the film to SO2. At the same time, the SO2 sensitivity is strongly affected by the ambient relative humidity (RH) and the response time is able to be tuned by changing the RH over a wide range. The mechanism of this dual response of the LCN film is ascribed to the neutralization of carboxylic acid and in situ acidification of the carboxylic salt. The reversibly and irreversibly humidity‐induced motion gated by SO2 renders the LCN film valuable in the design and preparation of multifunctional devices.
Bioresorbable Electronic Implants: History, Materials, Fabrication, Devices, and Clinical Applications
Authors: Cha Gi Doo , Kang Dayoung , Lee Jongha , Kim Dae‐Hyeong 
Published: April 2019

AbstractMedical implants, either passive implants for structural support or implantable devices with active electronics, have been widely used for the diagnosis and treatment of various diseases and clinical issues. These implants offer various functions, including mechanical support of biological structures in orthopedic and dental applications, continuous electrophysiological monitoring and feedback of electrical stimulation in neuronal and cardiac applications, and controlled drug delivery while maintaining arterial structure in drug‐eluting stents. Although these implants exhibit long‐term biocompatibility, surgery for their retrieval is often required, which imposes physical, biological, and economical burdens on the patients. Therefore, as an alternative to such secondary surgeries, bioresorbable implants that disappear after a certain period of time inside the body, including bioresorbable active electronics, have been highlighted recently. This review first discusses the historical background of medical implants and briefly define related terminology. Representative examples of non‐degradable medical implants for passive structural support and/or for diagnosis and therapy with active electronics are also provided. Then, recent progress in bioresorbable active implants composed of biosignal sensors, actuators for therapeutics, wireless power supply components, and their integrated systems are reviewed. Finally, clinical applications of these bioresorbable electronic implants are exemplified with brief conclusion and future outlook.
2D Electron Gas and Oxygen Vacancy Induced High Oxygen Evolution Performances for Advanced Co3O4/CeO2 Nanohybrids
Authors: Liu Ying , Ma Chao , Zhang Qinghua , Wang Wei , Pan Pengfei , Gu Lin , Xu Dongdong , Bao Jianchun , Dai Zhihui 
Published: April 2019

AbstractThe rational design of atomic‐scale interfaces in multiphase nanohybrids is an alluring and challenging approach to develop advanced electrocatalysts. Herein, through the selection of two different metal oxides with particular intrinsic features, advanced Co3O4/CeO2 nanohybrids (NHs) with CeO2 nanocubes anchored on Co3O4 nanosheets are developed, which show not only high oxygen vacancy concentration but also remarkable 2D electron gas (2DEG) behavior with ≈0.79 ± 0.1 excess e−/u.c. on the Ce3+ sites at the Co3O4–CeO2 interface. Such a 2DEG transport channel leads to a high carrier density of 3.8 × 1014 cm−2 and good conductivity. Consequently, the Co3O4/CeO2 NHs demonstrate dramatically enhanced oxygen evolution reaction (OER) performances with a low overpotential of 270 mV at 10 mA cm−2 and a high turnover frequency of 0.25 s−1 when compared to those of pure Co3O4 and CeO2 counterparts, outperforming commercial IrO2 and some recently reported representative OER catalysts. These results demonstrate the validity of tailoring the electrocatalytic properties of metal oxides by 2DEG engineering, offering a step forward in the design of advanced hybrid nanostructures.
Effect of Near‐Surface Dopants on the Epitaxial Growth of h‐BN on Metal Surfaces
Authors: Wei Wei , Lin Le , Zhang Guanhua , Ye Xiaoqiu , Bin Ren , Meng Caixia , Ning Yanxiao , Fu Qiang , Bao Xinhe 
Published: April 2019

AbstractEpitaxial growth of ultrathin overlayers on solid substrate is critically dependent on the surface structure, and in this work near‐surface doping is identified as another important growth factor. It is shown that growth of hexagonal boron nitride (h‐BN) on Ni(111) through chemical vapor deposition or surface ammonization can be strongly modulated by near‐surface B doping. Epitaxial h‐BN islands form on clean Ni(111) surface, while both epitaxial and nonepitaxial h‐BN islands grow on Ni(111) containing near‐surface B atoms. Quantitative correlation of epitaxial growth and near‐surface doping is unambiguously demonstrated. In situ spatially resolved surface science measurements based on photoemission electron microscopy and low energy electron microscopy in combination with density function calculations reveal that near‐surface B atoms weaken the interaction between h‐BN overlayer and Ni surface, which favor the nonepitaxial and metastable h‐BN structures. The present work suggests that near‐surface doping acts as an effective route to influence epitaxial growth of two‐dimensional (2D) material overlayers on solids.
Scalable Fabrication of Conductive Lines by Patterned Wettability‐Assisted Bar‐Coating for Low Cost Paper‐Based Circuits
Authors: Xin Zhiqing , Yan Meijia , Gu Lingya , Liu Jianghao , Liu Ruping , Li Luhai , Fang Yi , Mo Lixin , Li Yaling , Shen Yang , Guolin Xinzheng , Li Mingzhu , Yang Li 
Published: April 2019

AbstractPatterning technology on the paper based on wettability difference for paper‐based devices has attracted significant attention for its low cost, easy degradability, and high flexibility. Here, conductive lines are rapidly prepared by patterned wettability‐assisted bar‐coating for low cost paper‐based circuits. It is found that 7 s plasma treatment time for acquiring wettability difference is optimal, which resulted in not only effective splitting of the liquid film but also highly consistent line width with mask. Moreover, low retention force of hydrophobic surface is imperative for self‐confinement of the ink into hydrophilic areas, especially for ink with high solid content. The sheet resistance of patterns can reach 5 Ω ◻−1 after 980 nm laser sintering when using 50 wt% solid content ink with 110 cP viscosity. The geometries of line patterns, i.e., line width and spacing, can be readily tuned by varying the designed size of mask patterns. As‐prepared conductive patterns show good conductivity even after 500 bending cycles at 2 mm bending radius. It is believed that this study will provide deeper understanding of wettability difference‐assisted patterning process and represents a general strategy for selective wetting, especially for high viscosity ink.
Underwater Anisotropic 3D Superoleophobic Tracks Applied for the Directional Movement of Oil Droplets and the Microdroplets Reaction
Authors: Cheng Yang , Yang Qing , Fang Yao , Yong Jiale , Chen Feng , Hou Xun 
Published: April 2019

AbstractIn this paper, a simple way to fabricate underwater anisotropic superoleophobic tracks is reported for manipulating underwater oil droplets by the femtosecond laser etching and the oxygen plasma treatment. Laser ablation is able to generate micro/nanoscale hierarchical structures on the poly(dimethylsiloxane) (PDMS) surface. The textured PDMS surface is further turned from superhydrophobicity to hydrophilicity and underwater superoleophobicity by subsequent oxygen plasma irradiation. Underwater anisotropic 3D superoleophobic tracks can also be fabricated on the PDMS surface by the laser etching method. The width of the tracks depends on the laser‐treated area, while the depth of the tracks increases with increasing the laser power and the scanning number and with decreasing the laser scanning speed/space. The underwater superoleophobic 3D tracks show ultralow adhesion and anisotropic sliding property to oil droplets, thereby allow the underwater oil droplets to move just along the track. A microdroplets reaction is proposed based on the underwater superoleophobic tracks. There is no loss of the reactants during the whole reaction process. The anisotropic sliding property of underwater organic droplets will potentially have enormous applications in droplet manipulation, microfluidics system, surface lab‐chip devices, and chemical engineering.
2D Diluted Multiferroic Semiconductors upon Intercalation
Authors: Tu Zhengyuan , Wu Menghao 
Published: April 2019

AbstractThe direct combination of high‐mobility semiconductors and efficient multiferroic memories within the same material is desirable for integration of multifunctional electronics but remains a challenge. Stimulated by recent progress on intercalation of layered materials, first‐principles evidence of 2D room‐temperature multiferroicity in a series of doped metal dichalcogenides is shown, mainly focused on intercalated MoS2 and Bi2Se3. The intercalated ions may induce a switchable vertical polarization for high‐density recording as well as electrically tunable magnetism for highly efficient “electric writing + magnetic reading.” Akin to diluted magnetic semiconductors, certain multiferroic regions can be selectively formed via such doping, which can be directly integrated in the high‐mobility semiconductor wafer like n/p doping channels. In particular, other intriguing properties such as topological superconductivity may also be endowed in ferroelectric metal CuxBi2Se3. The bandgap of the intercalated systems can also be tuned via control of the doping density of ions, which may render a spatial‐varying bandgap for efficient light adsorption plus the enhanced exciton separation and open‐circuit voltage for ferroelectric photovoltaics.
Ruthenium‐Based Single‐Atom Alloy with High Electrocatalytic Activity for Hydrogen Evolution
Authors: Chen Cui‐Hong , Wu Deyao , Li Zhe , Zhang Rui , Kuai Chun‐Guang , Zhao Xue‐Ru , Dong Cun‐Ku , Qiao Shi‐Zhang , Liu Hui , Du Xi‐Wen 
Published: April 2019

AbstractHighly efficient and stable catalysts for the hydrogen evolution reaction, especially in alkaline conditions are crucial for the practical demands of electrochemical water splitting. Here, the synthesis of a novel RuAu single‐atom alloy (SAA) by laser ablation in liquid is reported. The SAA exhibits a high stability and a low overpotential, 24 mV@10 mA cm−2, which is much lower than that of a Pt/C catalyst (46 mV) in alkaline media. Moreover, the turnover frequency of RuAu SAA is three times that of Pt/C catalyst. Density functional theory computation indicates the excellent catalytic activity of RuAu SAAs originates from the relay catalysis of Ru and Au active sites. This work opens a new avenue toward high‐performance SAAs via fast quenching of immiscible metals.
Evidencing Excellent Thermal‐ and Photostability for Single‐Component Organic Solar Cells with Inherently Built‐In Microstructure
Authors: He Yakun , Heumüller Thomas , Lai Wenbin , Feng Guitao , Classen Andrej , Du Xiaoyan , Liu Chao , Li Weiwei , Li Ning , Brabec Christoph J. 
Published: April 2019

AbstractSolution‐processed organic solar cells (OSCs) are promising low‐cost, flexible, portable renewable sources for future energy supply. The state‐of‐the‐art OSCs are typically fabricated from a bulk‐heterojunction (BHJ) active layer containing well‐mixed donor and acceptor molecules in the nanometer regime. However, BHJ solar cells suffer from stability problems caused by the severe morphological changes upon thermal or illumination stress. In comparison, single‐component organic solar cells (SCOSCs) based on a double‐cable conjugated polymer with a covalently stabilized microstructure is suggested to be a key strategy for superior long‐term stability. Here, the thermal‐ and photostability of SCOSCs based on a model double‐cable polymer is systematically investigated. It is encouraging to find that under 90 °C & 1 sun illumination, the performance of SCOSCs remains substantially stable. Transport measurements show that charge generation and recombination (lifetime and recombination order) hardly change during the aging process. Particularly, the SCOSCs exhibit ultrahigh long‐term thermal stability with 100% PCE remaining after heating at temperature up to 160 °C for over 400 h, indicating an excellent candidate for extremely rugged applications.
Ambient‐Pressure Relithiation of Degraded LixNi0.5Co0.2Mn0.3O2 (0 < x < 1) via Eutectic Solutions for Direct Regeneration of Lithium‐Ion Battery Cathodes
Authors: Shi Yang , Zhang Minghao , Meng Ying Shirley , Chen Zheng 
Published: April 2019

AbstractWith the rapid growth of the lithium‐ion battery (LIBs) market, recycling and re‐use of end‐of‐life LIBs to reclaim lithium (Li) and transition metal (TM) resources (e.g., Co, Ni), as well as eliminating pollution from disposal of waste batteries, has become an urgent task. Here, for the first time the ambient‐pressure relithiation of degraded LiNi0.5Co0.2Mn0.3O2 (NCM523) cathodes via eutectic Li+ molten‐salt solutions is successfully demonstrated. Combining such a low‐temperature relithiation process with a well‐designed thermal annealing step, NCM523 cathode particles with significant Li loss (≈40%) and capacity degradation (≈50%) can be successfully regenerated to achieve their original composition and crystal structures, leading to effective recovery of their capacity, cycling stability, and rate capability to the levels of the pristine materials. Advanced characterization tools including atomic resolution electron microscopy imaging and electron energy loss spectroscopy are combined to demonstrate that NCM523's original layered crystal structure is recovered. For the first time, it is shown that layer‐to‐rock salt phase change on the surfaces and subsurfaces of the cathode materials can be reversed if lithium can be incorporated back to the material. The result suggests the great promise of using eutectic Li+ molten–salt solutions for ambient‐pressure relithiation to recycle and remanufacture degraded LIB cathode materials.
Unraveling the Potassium Storage Mechanism in Graphite Foam
Authors: Liu Jilei , Yin Tingting , Tian Bingbing , Zhang Bowei , Qian Cheng , Wang Zhiqiang , Zhang Lili , Liang Pei , Chen Zhen , Yan Jiaxu , Fan Xiaofeng , Lin Jianyi , Chen Xiaohua , Huang Yizhong , Loh Kian Ping , Shen Ze Xiang 
Published: April 2019

AbstractPotassium‐intercalated graphite intercalation compounds (K‐GICs) are of particular physical and chemical interest due to their versatile structures and fascinating properties. Fundamental insights into the K+ storage mechanism, and the complex kinetics/thermodynamics that control the reactions and structural rearrangements allow manipulating K‐GICs with desired functionalities. Here operando studies including in situ Raman mapping and in situ X‐ray diffraction (XRD) characterizations, in combination with density‐functional theory simulations are carried out to correlate the real‐time electrochemical K+ intercalation/deintercalation process with structure/component evolution. The experimental results, together with theoretical calculations, reveal the reversible K‐GICs staging transition: C ↔ stage 5 (KC60) ↔ stage 4 (KC48) ↔ stage 3 (KC36) ↔ stage 2 (KC24/KC16) ↔ stage 1 (KC8). Moreover, the staging transition is clearly visualized and an intermediate phase of stage 2 with the stoichiometric formula of KC16 is identified. The staging transition mechanism involving both intrastage transition from KC24 (stage 2) to KC16 (stage 2) and interstage transition is proposed. The present study promotes better fundamental understanding of K+ storage behavior in graphite, develops a nondestructive technological basis for accurately capture nonuniformity in electrode phase evolution across the length scale of graphite domains, and offers guidance for efficient research in other GICs.
Revealing the Short‐Circuiting Mechanism of Garnet‐Based Solid‐State Electrolyte
Authors: Song Yongli , Yang Luyi , Zhao Wenguang , Wang Zijian , Zhao Yan , Wang Ziqi , Zhao Qinghe , Liu Hao , Pan Feng 
Published: April 2019

AbstractGarnet‐type solid‐state electrolytes (SSEs) have been widely studied as a promising candidate for Li metal batteries. Despite the common belief that inorganic SSEs can prevent dendrite propagation, garnet SSEs suffer from relatively low critical current density (CCD) at which the SSEs are abruptly short‐circuited by Li dendrites. In this study, the short‐circuiting mechanism of garnet Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) is investigated. It is found that instead of propagating uniaxially from one electrode to other in a dendritic form, metallic lithium is formed within the SSE. This can be attributed to the fact that electrons combine with Li ions at the grain boundary, which exhibits relatively high electronic conductivity, and then reduce Li+ to Li0 to cause short circuits. In order to reduce the electronic conductivity at the grain boundary, a thin layer of LiAlO2 is coated on the grain surface of LLCZN, which results in an improved CCD value. It is also found that under higher external voltages, the electronic conductivity of SSE becomes more significant, which is believed to be the origin of CCD. These findings not only shed light on the short‐circuiting mechanism of garnet‐type SSEs but also offer a novel perspective and useful guidance on their designs and modifications.