bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing Melittin‐Graphene Hybrid Complexes for Enhanced Antibacterial Activity
Authors: Lu Xuemei , Liu Jiaojiao , Gou Lu , Li Jingliang , Yuan Bing , Yang Kai , Ma Yuqiang 
Published: March 2019

AbstractAntimicrobial peptides (AMPs) promise a fundamental solution to the devastating threat of drug‐resistant bacteria. However, drawbacks of AMPs (e.g., poor cell membrane penetration efficiency) seriously block their clinical use. In this work, rational design of a hybrid complex of melittin (as a representative AMP) and graphene or graphene oxide (Gra or GO) nanosheets for enhanced antibacterial ability is achieved, via combining in‐silico prediction and in‐tube test. In comparison to pristine melittin, the specifically designed AMP‐Gra (/GO) complex exhibits remarkable efficiency in transmembrane perforation with an over tenfold decrease in the threshold working concentration of peptide; moreover, it has an up to 20‐fold enhancement in antibacterial activity against both Gram‐negative and Gram‐positive bacteria. Such improvement is ascribed to the synergetic insertion of nanosheets and melittin due to similarity in antibacterial mechanism between them and is further regulated by the structural factors of the complex, including the intersheet spacing and surface functionalization of the Gra/GO sheets, etc. These results provide practical guidelines to engineer AMPs with nanotechnology for improved antimicrobial performances, especially based on targeted functionalization of the Gra/GO nanosheets.
Self‐Assembling Proteins as High‐Performance Substrates for Embryonic Stem Cell Self‐Renewal
Authors: Hill Christopher J. , Fleming Jennifer R. , Mousavinejad Masoumeh , Nicholson Rachael , Tzokov Svetomir B. , Bullough Per A. , Bogomolovas Julius , Morgan Mark R. , Mayans Olga , Murray Patricia 
Published: March 2019

AbstractThe development of extracellular matrix mimetics that imitate niche stem cell microenvironments and support cell growth for technological applications is intensely pursued. Specifically, mimetics are sought that can enact control over the self‐renewal and directed differentiation of human pluripotent stem cells (hPSCs) for clinical use. Despite considerable progress in the field, a major impediment to the clinical translation of hPSCs is the difficulty and high cost of large‐scale cell production under xeno‐free culture conditions using current matrices. Here, a bioactive, recombinant, protein‐based polymer, termed ZTFn, is presented that closely mimics human plasma fibronectin and serves as an economical, xeno‐free, biodegradable, and functionally adaptable cell substrate. The ZTFn substrate supports with high performance the propagation and long‐term self‐renewal of human embryonic stem cells while preserving their pluripotency. The ZTFn polymer can, therefore, be proposed as an efficient and affordable replacement for fibronectin in clinical grade cell culturing. Further, it can be postulated that the ZT polymer has significant engineering potential for further orthogonal functionalization in complex cell applications.
Large‐Scale, Low‐Power Nonvolatile Memory Based on Few‐Layer MoS2 and Ultrathin Polymer Dielectrics
Authors: Yang Sang Cheol , Choi Junhwan , Jang Byung Chul , Hong Woonggi , Shim Gi Woong , Yang Sang Yoon , Im Sung Gap , Choi Sung‐Yool 
Published: March 2019

AbstractWith the advent of artificial intelligence and the Internet of Things, demand has grown for flexible, low‐power, high‐density nonvolatile memory capable of handling vast amounts of information. Ultrathin‐layered 2D semiconductor materials such as molybdenum disulfide (MoS2) have considerable potential for flexible electronic device applications because of their unique physical properties. However, development of flexible MoS2‐based flash memory is challenging, as there is a lack of flexible dielectric materials with sufficient insulating properties for use in flash memory devices with dielectric bilayers. Here, large‐scale, low‐power nonvolatile memory is realized based on a chemical vapor deposition (CVD)‐grown millimeter‐scale few‐layer MoS2 semiconductor channel and polymer dielectrics prepared via an initiated CVD (iCVD) process. Using the outstanding insulating properties and solvent‐free nature of iCVD, fabricated memory devices with a tunable memory window, a high on/off ratio (≈106), low operating voltages (≈13 V), stable retention times exceeding 105 s with a possible extrapolated duration of years, and cycling endurance exceeding 1500 cycles are demonstrated. Owing to these characteristics, these devices distinctly outperform previously reported MoS2‐based memory devices. Leveraging the inherent mechanical flexibility of both ultrathin polymer dielectrics and MoS2, this work is a step toward realization of large‐scale, low‐power, flexible MoS2‐based flash memory.
Band Structure and Spin–Orbital Texture of the (111)‐KTaO3 2D Electron Gas
Authors: Bruno Flavio Y. , McKeown Walker Siobhan , Riccò Sara , de la Torre Alberto , Wang Zhiming , Tamai Anna , Kim Timur K. , Hoesch Moritz , Bahramy Mohammad S. , Baumberger Felix 
Published: March 2019

Abstract2D electron gases (2DEGs) in oxides show great potential for the discovery of new physical phenomena and at the same time hold promise for electronic applications. In this work, angle‐resolved photoemission is used to determine the electronic structure of a 2DEG stabilized in the (111)‐oriented surface of the strong spin–orbit coupling material KTaO3. The measurements reveal multiple sub‐bands that emerge as a consequence of quantum confinement and form a sixfold symmetric Fermi surface. This electronic structure is well reproduced by self‐consistent tight‐binding supercell calculations. Based on these calculations, the spin and orbital texture of the 2DEG is determined. It is found that the 2DEG Fermi surface is derived from bulk J = 3/2 states and exhibits an unconventional anisotropic Rashba‐like lifting of the spin‐degeneracy. Spin‐momentum locking holds only for high‐symmetry directions and a strong out‐of‐plane spin component renders the spin texture threefold symmetric. It is found that the average spin‐splitting on the Fermi surface is an order of magnitude larger than in SrTiO3, which should translate into an enhancement in the spin–orbitronic response of (111)‐KTaO3 2DEG‐based devices.
An allometry between seed kernel and seed coat shows greater investment in physical defense in small seeds
Authors: Wu La‐Mei , Chen Si‐Chong , Wang Bo 
Published: March 2019

Premise of the StudyNumerous studies have treated the mass of a whole seed as an integrated unit, although the components seed kernel and seed coat play different roles and are subject to different evolutionary selection pressures. In this study, we provided the first global‐scale quantification of the relative biomass investments in seed coats and seed kernels. We tested the following hypotheses: there is a negative allometry between seed kernel mass and seed coat mass, and therefore, seed coat ratio (SCR) is negatively correlated with seed mass.MethodsWe compiled a global‐scale data set from the published literature, including 680 plant species from 420 genera and 108 families. The relationships between seed components were quantified using standardized major axis regression, ordinary least squares regression, and phylogenetic independent analyses.Key ResultsWe found a weak but significantly negative allometry between seed kernel mass and seed coat mass, which resulted in a negative relationship between seed mass and SCR. Similar results were found after accounting for the phylogeny.ConclusionsThe finding that smaller seeds invest more in protective tissues but less in stored reserves may explain the general prediction that larger seeds suffer greater predation than smaller seeds. Furthermore, this weak allometry may also explain, at least in part, why so many studies failed to identify a clear pattern of the effect of seed mass on many ecological processes. Our study suggests that the allometry between the two seed components must be considered when evaluating the ecological significance and evolutionary history of seed mass.
Silver Tarnishing Mechanism Revealed by Molecular Dynamics Simulations
Authors: Saleh Gabriele , Xu Chen , Sanvito Stefano 
Published: March 2019

AbstractThe mechanism of silver–oxygen and silver–sulfur reactions is revealed by means of molecular dynamics simulations, performed with reactive force fields purposely built and extensively tested against quantum‐chemical results. Different reaction mechanisms and rates for Ag–O and Ag–S emerge. This study solves the long‐lasting question why silver exposed to the environment is strongly vulnerable to sulfur corrosion (tarnishing) but hardly reacts with O2, despite the thermodynamic prediction that both oxide and sulfide should form. The reliability of the simulation results is confirmed by the agreement with a multitude of experimental results from the literature.
Total Synthesis of (−)‐Cephalotaxine and (−)‐Homoharringtonine via Furan Oxidation–Transannular Mannich Cyclization
Authors: Ju Xuan , Beaudry Christopher M. 
Published: March 2019

AbstractHomoharringtonine and its congener cephalotaxine were synthesized. Oxidative ring‐opening of a furan unveils an amine‐tethered dicarbonyl, which undergoes spontaneous transannular Mannich cyclization. The cascade builds the full cephalotaxine substructure in a single operation in 60 % yield. A Noyori reduction enabled synthesis of the title compounds with excellent enantioselectivity (krel=278).
Rheologically determined phase diagram of poly(ε‐caprolactone)/poly(styrene‐co‐acrylonitrile) blends: Role of ramp rate in dynamic measurements
Authors: Naziri Amir Ali , Khonakdar Hossein Ali , Hemmati Farkhondeh , Jafari Seyed Hassan , Ehsani Morteza 
Published: March 2019

ABSTRACTThe phase behavior of poly(ε‐caprolactone) (PCL)/poly(styrene‐co‐acrylonitrile) (SAN) blends, with a lower critical solution temperature (LCST)‐type phase diagram over a virtual upper critical solution temperature (UCST) one, was investigated through thermal analysis and dynamic rheological measurements as a function of ramp rate. The LCST phase diagram was detected rheologically from the observed slope changes in the dynamic temperature ramps of storage modulus (G′). The determined phase transition points along with the spinodal temperatures, which are estimated based on the theoretical approach of Ajji and Choplin's mean field theory, shift to higher temperatures by reducing the ramp rate. The detected shifts show a composition dependency. Far away from the critical point, the phase transition temperatures of PCL/SAN blends change more noticeably, which originates from the smaller magnitude of concentration fluctuations in the metastable region and the stronger competition between the phase dissolution and cooling rate. The Flory–Huggins interaction parameter (χ) was appropriately adjusted into the LCST phase boundary as a function of temperature and composition. The results confirmed that the adjusted χ has higher temperature dependency at larger ramp rate of the dynamic measurements. The experimentally combined LCST and UCST phase behavior were also verified by the compressible regular solution model. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47750.
Local and long range potentials for heparin‐protein systems for coarse‐grained simulations
Authors: Samsonov Sergey A. , Lubecka Emilia A. , Bojarski Krzysztof K. , Ganzynkowicz Robert , Liwo Adam 
Published: March 2019

AbstractHeparin belongs to glycosaminoglycans (GAGs), a class of periodic linear anionic polysaccharides, which are functionally important components of the extracellular matrix owing to their interactions with various protein targets. Heparin is known to be involved in many cell signaling processes, while the experimental data available for heparin are significantly more abundant than for other GAGs. At the same time, the length and conformational flexibility of the heparin represent major challenges for its theoretical analysis. Coarse‐grained (CG) approaches, which enable us to extend the size‐ and time‐scale by orders of magnitude owing to reduction of system representation, appear, therefore, to be useful in simulating these systems. In this work, by using umbrella‐sampling molecular dynamics simulations, we derived and parameterized the CG backbone‐local potentials of heparin chains and the orientational potentials for the interactions of heparin with amino acid side chains to be further included in the physics‐based Unified Coarse‐Grained Model of biological macromolecules. With these potentials, simulations of extracellular matrix processes where both heparin and multiple proteins participate will be possible.
Flour from Triticum polonicum L. as a potential ingredient in bread production
Authors: Suchowilska Elżbieta , Szafrańska Anna , Słowik Elżbieta , Wiwart Marian 
Published: March 2019

AbstractBackground and objectivesThe experiment involved 35 lines of Triticum polonicum, three common wheat cultivars, and one durum wheat cultivar.FindingsTriticum polonicum lines were characterized by significantly higher protein (17.33%) and ash (2.30%) content than Triticum aestivum (11.65 and 1.90%, respectively). Despite the high gluten content of T. polonicum (37.1%), its gluten index (11%) and falling number (182 s) were lower in comparison with T. aestivum (82% and 397 s, respectively). The dough and bread made from T. polonicum flour were characterized by high yield and high crumb moisture. The loaves of bread baked from T. polonicum flour were generally less risen, and in some cases, they were flatter in shape and had less fluffy crumb with somewhat larger and thicker‐walled pores than the breads made from common wheat and durum wheat flour.ConclusionsHowever, T. polonicum bread had more desirable sensory properties than the products made with the flour of common wheat and durum wheat. The flour from T. polonicum grain can be an interesting alternative for bread production.Significance and noveltySo far, there is no information on the technological quality of the grain of T. polonicum. This species could be a valuable initial material for new wheat cultivars breeding.
The efficacy of fecal microbiota transplantation for patients with chronic pouchitis: A case series
Authors: Nishida Atsushi , Imaeda Hirotsugu , Inatomi Osamu , Bamba Shigeki , Sugimoto Mitsushige , Andoh Akira 
Published: March 2019

Key Clinical MessagePouchitis is one of the most common complications that develop after restorative proctocolectomy with ileal pouch‐anal anastomosis for ulcerative colitis. Single fecal microbiota transplantation (FMT) by colonoscopy was performed safely on three patients with pouchitis. However, the efficacy of FMT on pouchitis was limited.
Recent Progress on Two‐Dimensional Heterostructures for Catalytic, Optoelectronic, and Energy Applications
Authors: Xi Yilian , Zhuang Jincheng , Hao Weichang , Du Yi 
Published: March 2019

AbstractTwo‐dimensional (2D) heterostructures have attracted tremendous attention over the past few years, owing to the fascinating electronic and photoelectric properties determined by the heterointerface of different components, which has led to significant efforts being devoted to exploring novel applications based on 2D heterostructures in the field of nanomaterials. Here, recent progress on the features of 2D heterostructures that make them the promising candidates for electronic and optoelectronic applications are discussed. The potential applications of these 2D heterostructures, based on the experimental results, as field‐effect transistors (FETs), diodes, solar cells, photocatalysis, and photodetectors, are reviewed and their challenges and outlook are considered.
Robust Triplatinum Redox‐Chromophore for a Post‐Synthetic Color‐Tunable Electrochromic System
Authors: Yoshida Masaki , Shitama Hotaka , Sameera W. M. C. , Kobayashi Atsushi , Kato Masako 
Published: March 2019

AbstractAn electrochromic system showing ease of color tunability has been constructed using a triple‐decker PtII complex [Pt3(μ3‐pydt)2(bpy)3]2+ (H2pydt=2,6‐pyridinedithiol, bpy=2,2′‐bipyridine). The divalent complex undergoes electrochemically quasi‐reversible two‐electron transfer coupled with the coordination/dissociation of axial ligands, forming higher valent Pt(+2.67) species [Pt3X2(μ3‐pydt)2(bpy)3]2+ (X=Cl−, Br−, and SCN−). These higher valent species exhibit characteristic colors ranging from red to cyan depending on the counter anion X− of the electrolyte. The triple‐decker structure provides a novel multicolor electrochromic system with favorable stability and reversibility. Theoretical calculations indicate that the colors of the Pt(+2.67) species are tunable by the trans influence of the axial ligand X−. This novel strategy of post‐synthetic color‐tuning using triplatinum systems should enable the facile preparation of colorful electrochromic devices without any complicated procedures, which may find application in flexible displays, optical devices, and sensors.
Across the Board: Keiichi Tomishige
Authors: Tomishige Keiichi 
Published: March 2019

AbstractIn this series of articles, the board members of ChemSusChem discuss recent research articles that they consider of exceptional quality and importance for sustainability. This entry features Prof. K. Tomishige, who highlights the importance of the chemical conversion of monosaccharides and the future necessity for the development of heterogeneous catalysts.
Morphological and digestive adjustments buffer performance: How staging shorebirds cope with severe food declines
Authors: Zhang Shou‐Dong , Ma Zhijun , Choi Chi‐Yeung , Peng He‐Bo , Melville David S. , Zhao Tian‐Tian , Bai Qing‐Quan , Liu Wen‐Liang , Chan Ying‐Chi , van Gils Jan A. , Piersma Theunis 
Published: March 2019

AbstractOrganisms cope with environmental stressors by behavioral, morphological, and physiological adjustments. Documentation of such adjustments in the wild provides information on the response space in nature and the extent to which behavioral and bodily adjustments lead to appropriate performance effects. Here we studied the morphological and digestive adjustments in a staging population of migrating Great Knots Calidris tenuirostris in response to stark declines in food abundance and quality at the Yalu Jiang estuarine wetland (northern Yellow Sea, China). At Yalu Jiang, from 2011 to 2017 the densities of intertidal mollusks, the food of Great Knots, declined 15‐fold. The staple prey of Great Knots shifted from the relatively soft‐shelled bivalve Potamocorbula laevis in 2011–2012 to harder‐shelled mollusks such as the gastropod Umbonium thomasi in 2016–2017. The crushing of the mollusks in the gizzard would require a threefold to 11‐fold increase in break force. This was partially resolved by a 15% increase in gizzard mass which would yield a 32% increase in shell processing capacity. The consumption of harder‐shelled mollusks was also accompanied by reliance on regurgitates to excrete unbreakable parts of prey, rather than the usual intestinal voidance of shell fragments as feces. Despite the changes in digestive morphology and strategy, there was still an 85% reduction in intake rate in 2016–2017 compared with 2011–2012. With these morphological and digestive adjustments, the Great Knots remaining faithful to the staging site to a certain extent buffered the disadvantageous effects of dramatic food declines. However, compensation was not complete. Locally, birds will have had to extend foraging time and use a greater daily foraging range. This study offers a perspective on how individual animals may mitigate the effects of environmental change by morphological and digestive strategies and the limits to the response space of long‐distance migrating shorebirds in the wild.
Pteropus lylei primarily forages in residential areas in Kandal, Cambodia
Authors: Choden Kinley , Ravon Sébastien , Epstein Jonathan H. , Hoem Thavry , Furey Neil , Gely Marie , Jolivot Audrey , Hul Vibol , Neung Chhoeuth , Tran Annelise , Cappelle Julien 
Published: March 2019

Abstract

Bats are the second most species‐rich Mammalian order and provide a wide range of ecologically important and economically significant ecosystem services. Nipah virus is a zoonotic emerging infectious disease for which pteropodid bats have been identified as a natural reservoir. In Cambodia, Nipah virus circulation has been reported in Pteropus lylei, but little is known about the spatial distribution of the species and the associated implications for conservation and public health.

We deployed Global Positioning System (GPS) collars on 14 P. lylei to study their movements and foraging behavior in Cambodia in 2016. All of the flying foxes were captured from the same roost, and GPS locations were collected for 1 month. The habitats used by each bat were characterized through ground‐truthing, and a spatial distribution model was developed of foraging sites.

A total of 13,643 valid locations were collected during the study. Our study bats flew approximately 20 km from the roost each night to forage. The maximum distance traveled per night ranged from 6.88–105 km and averaged 28.3 km. Six of the 14 bats visited another roost for at least one night during the study, including one roost located 105 km away.

Most foraging locations were in residential areas (53.7%) followed by plantations (26.6%). Our spatial distribution model confirmed that residential areas were the preferred foraging habitat for P. lylei, although our results should be interpreted with caution due to the limited number of individuals studied.

Synthesis and applications: Our findings suggest that the use of residential and agricultural habitats by P. lylei may create opportunities for bats to interact with humans and livestock. They also suggest the importance of anthropogenic habitats for conservation of this vulnerable and ecologically important group in Cambodia. Our mapping of the probability of occurrence of foraging sites will help identification of areas where public awareness should be promoted regarding the ecosystem services provided by flying foxes and potential for disease transmission through indirect contact.
Antipredator response diminishes during periods of resource deficit for a large herbivore
Authors: Oates B. A. , Merkle J. A. , Kauffman M. J. , Dewey S. R. , Jimenez M. D. , Vartanian J. M. , Becker S. A. , Goheen J. R. 
Published: March 2019

AbstractThe starvation–predation hypothesis predicts that, during resource shortages, prey forego antipredator behavior and forage as much as possible to avoid starvation, even when risk of predation is high. We tested this hypothesis using GPS locations collected simultaneously from moose (Alces alces) and wolves (Canis lupus) in the Greater Yellowstone Ecosystem of North America. We assessed shifts in the speed, displacement, and habitat selection of moose 24 h following encounter with wolves (0–1,500 m distance). We examined whether the strength of antipredator behaviors would weaken as winter progressed and the nutritional condition of moose declined. Moose responded to wolf encounters by increasing their rate of movement in early winter, but only within 500 m distance. Importantly, these responses attenuated as winter progressed. Moose did not avoid their preferred foraging habitat (riparian areas) following encounters with wolves at any distance, and instead they more strongly selected riparian areas, especially in early winter. Our findings support theoretical predictions that resource deficits should dampen prey antipredator behavior, and suggest that nutritional condition of prey may buffer against run‐away risk effects in food webs involving large mammalian predators and prey.