bluuebunny/crossref_metadata_2025_split huggingface dataset:
Double‐Network Heparin Dynamic Hydrogels: Dynagels as Anti‐bacterial 3D Cell Culture Scaffolds
Authors: Cui Han , Wang Qimeng , Zhang Ye , Barboiu Mihail , Zhang Yan , Chen Jinghua 
Published: March 2021

AbstractDouble cross‐linked dynamic hydrogels, dynagels, have been prepared through reversible imine bonds and supramolecular interactions, which showed good pH responsiveness, injectability, self‐healing property and biocompatibility. With the further encapsulation of heparin, the obtained hydrogels exhibited good anti‐bacterial activity and promotion effects for 3D cell culture.
Mapping C−H⋅⋅⋅M Interactions in Confined Spaces: (α‐ICyDMe)Au, Ag, Cu Complexes Reveal “Contra‐electrostatic H Bonds” Masquerading as Anagostic Interactions**
Authors: dos Passos Gomes Gabriel , Xu Guangcan , Zhu Xiaolei , Chamoreau Lise‐Marie , Zhang Yongmin , Bistri‐Aslanoff Olivia , Roland Sylvain , Alabugin Igor V. , Sollogoub Matthieu 
Published: March 2021

AbstractWhat happens when a C−H bond is forced to interact with unpaired pairs of electrons at a positively charged metal? Such interactions can be considered as “contra‐electrostatic” H‐bonds, which combine the familiar orbital interaction pattern characteristic for the covalent contribution to the conventional H‐bonding with an unusual contra‐electrostatic component. While electrostatics is strongly stabilizing component in the conventional C−H⋅⋅⋅X bonds where X is an electronegative main group element, it is destabilizing in the C−H⋅⋅⋅M contacts when M is Au(I), Ag(I), or Cu(I) of NHC−M−Cl systems. Such remarkable C−H⋅⋅⋅M interaction became experimentally accessible within (α‐ICyDMe)MCl, NHC‐Metal complexes embedded into cyclodextrins. Computational analysis of the model systems suggests that the overall interaction energies are relatively insensitive to moderate variations in the directionality of interaction between a C−H bond and the metal center, indicating stereoelectronic promiscuity of fully filled set of d‐orbitals. A combination of experimental and computational data demonstrates that metal encapsulation inside the cyclodextrin cavity forces the C−H bond to point toward the metal, and reveals a still attractive “contra‐electrostatic” H‐bonding interaction.
Acetylenic Replacement of Albicidin's Methacrylamide Residue Circumvents Detrimental E/Z Photoisomerization and Preserves Antibacterial Activity
Authors: Behroz Iraj , Kleebauer Leonardo , Hommernick Kay , Seidel Maria , Grätz Stefan , Mainz Andi , Weston John B. , Süssmuth Roderich D. 
Published: March 2021

AbstractThe natural product albicidin is a highly potent inhibitor of bacterial DNA gyrase. Its outstanding activity, particularly against Gram‐negative pathogens, qualifies it as a promising lead structure in the search for new antibacterial drugs. However, as we show here, the N‐terminal cinnamoyl moiety of albicidin is susceptible to photochemical E/Z isomerization. Moreover, the newly formed Z isomer exhibits significantly reduced antibacterial activity, which hampers the development and biological evaluation of albicidin and potent derivatives thereof. Hence, we synthesized 13 different variants of albicidin in which the vulnerable para‐coumaric acid moiety was replaced; this yielded photostable analogues. Biological activity assays revealed that diaryl alkyne analogues exhibited virtually undiminished antibacterial efficacy. This promising scaffold will therefore serve as a blueprint for the design of a potent albicidin‐based drug.
Acetophenyl‐thienyl‐aniline‐Linked Nucleotide for Construction of Solvatochromic Fluorescence Light‐Up DNA Probes Sensing Protein‐DNA Interactions
Authors: Güixens‐Gallardo Pedro , Hocek Michal 
Published: March 2021

AbstractThe synthesis of 2′‐deoxycytidine and its 5′‐O‐triphosphate bearing solvatochromic acetophenyl‐thienyl‐aniline fluorophore was developed using the Sonogashira cross‐coupling reaction as the key step. The triphosphate was used for polymerase synthesis of labelled DNA. The labelled nucleotide or DNA exerted weak red fluorescence when excited at 405 nm, but a significant colour change (to yellow or green) and light‐up (up to 20 times) was observed when the DNA probes interacted with proteins or lipids.
Chalcogen Bonding Ion‐Pair Cryptand Host Discrimination of Potassium Halide Salts
Authors: Docker Andrew , Bunchuay Thanthapatra , Ahrens Michael , Martinez‐Martinez Antonio J. , Beer Paul D. 
Published: March 2021

AbstractA series of chalcogen, halogen and hydrogen bonding heteroditopic macrobicyclic cryptands are reported and their potassium halide ion‐pair recognition properties investigated. Saliently, the co‐bound potassium cation was determined to be crucial in switching on the bromide and iodide recognition properties of the respective cryptand receptor. Importantly, the nature of the sigma‐hole mediated interaction employed in the anion recognition component is demonstrated to significantly augment the ion‐pair binding behaviour, markedly so for the halogen bonding analogue. Most notably the incorporation of a chelating chalcogen bonding donor motif significantly improves the selectivity towards KBr over KI, relative to halogen and hydrogen bonding analogues.
Catalytic Reductive Cross‐Coupling between Aromatic Aldehydes and Arylnitriles
Authors: Mitsui Atsuhisa , Nagao Kazunori , Ohmiya Hirohisa 
Published: March 2021

AbstractA reductive cross‐coupling reaction between aromatic aldehydes and arylnitriles using a copper catalyst and a silylboronate as a reductant is reported. This protocol represents an unprecedented approach to the chemoselective synthesis of α‐hydroxy ketones by electrophile–electrophile cross‐coupling.
Covalent 2D Patterning, Local Electronic Structure and Polarization Switching of Graphene at the Nanometer Level
Authors: Bao Lipiao , Zhao Baolin , Assebban Mhamed , Halik Marcus , Hauke Frank , Hirsch Andreas 
Published: March 2021

AbstractA very facile and efficient protocol for the covalent patterning and properties tuning of graphene is reported. Highly reactive fluorine radicals were added to confined regions of graphene directed by laser writing on graphene coated with 1‐fluoro‐3,3‐dimethylbenziodoxole. This process allows for the realization of exquisite patterns on graphene with resolutions down to 200 nm. The degree of functionalization, ranging from the unfunctionalized graphene to extremely high functionalized graphene, can be precisely tuned by controlling the laser irradiation time. Subsequent substitution of the initially patterned fluorine atoms afforded an unprecedented graphene nanostructure bearing thiophene groups. This substitution led to a complete switch of both the electronic structure and the polarization within the patterned graphene regions. This approach paves the way towards the precise modulation of the structure and properties of nanostructured graphene.
High throughput can produce better decisions than high accuracy when phenotyping plant populations
Authors: Lane Holly M. , Murray Seth C. 
Published: March 2021

AbstractStudies assessing phenotypes of plant populations traditionally place their primary focus on increasing measurement precision and improving accuracy. Phenotyping methods that use imaging, remote sensing, and spectroscopy, continue to increase throughput capacity, but information has been unavailable to assess the tradeoffs between increased throughput and any potential decreases in measurement accuracy. In this simulation study, we compare four levels of measurement accuracy across varying levels of throughput, and discuss how an increased error rate can be compensated for via increased throughput, if experimental resources are allocated appropriately. Under the tested scenarios of increased throughput, the correct values of genotypes were best estimated by increasing the number of environments. Genetic mapping studies should increase population size as well to see improvements over more accurate measurement methods. This simplistic simulation mimics many empirical findings and will be of interest to any researcher interested in assessing how high‐throughput phenotyping methods affect decision‐making in crop research programs.
Higher‐order inertial Alfvén wave dressed solitons, quasiperiodic structures, and chaos in plasmas
Authors: Mahmood Shahzad , Ur‐Rehman Hafeez , Ali Munazza Zulfiqar , Basit Abdul 
Published: March 2021

AbstractThe higher‐order, low‐amplitude inertial Alfvén wave (IAW) dressed soliton and chaos are investigated in a magnetized plasma. In the linear limit, the dispersion relation for propagation of IAWs in plasmas is also obtained in the presence of electron thermal effects and illustrated numerically. It is found that the electron inertial length plays an important role for wave dispersion effects and its phase speed is increased on including the electron temperature in the model. The reductive perturbation method is employed to obtain the first‐order IAW Korteweg–de Vries (KdV) soliton and second‐order dressed soliton solutions analytically, which gives electron density dip (or rarefactive) structure and moves with super Alfvénic speed in plasmas. The numerical illustrations of the KdV and dressed IAW solitons are also presented by using the laboratory and space plasma parameters given in the literature. Furthermore, a numerical study of quasi‐periodicity and chaotic behaviour of IAWs in the presence of external periodic force is also discussed in detail. The effects of plasma beta (which depends on plasma density, electron temperature, and magnetic field intensity) and obliqueness of the wave propagation on the formation of nonlinear Alfvénic wave structures have also been presented.
Traits explain invasion of alien plants into tropical rainforests
Authors: Junaedi Decky I. , Guillera‐Arroita Gurutzeta , Vesk Peter A. , McCarthy Michael A. , Burgman Mark A. , Catford Jane A. 
Published: March 2021

Abstract1. The establishment of new botanic gardens in tropical regions highlights a need for weed risk assessment tools suitable for tropical ecosystems. The relevance of plant traits for invasion into tropical rainforests has not been well studied.2. Working in and around four botanic gardens in Indonesia where 590 alien species have been planted, we estimated the effect of four plant traits, plus time since species introduction, on: (a) the naturalization probability and (b) abundance (density) of naturalized species in adjacent native tropical rainforests; and (c) the distance that naturalized alien plants have spread from the botanic gardens.3. We found that specific leaf area (SLA) strongly differentiated 23 naturalized from 78 non‐naturalized alien species (randomly selected from 577 non‐naturalized species) in our study. These trends may indicate that aliens with high SLA, which had a higher probability of naturalization, benefit from at least two factors when establishing in tropical forests: high growth rates and occupation of forest gaps. Naturalized aliens had high SLA and tended to be short. However, plant height was not significantly related to species' naturalization probability when considered alongside other traits.4. Alien species that were present in the gardens for over 30 years and those with small seeds also had higher probabilities of becoming naturalized, indicating that garden plants can invade the understorey of closed canopy tropical rainforests, especially when invading species are shade tolerant and have sufficient time to establish.5. On average, alien species that werenotanimal dispersed spread 78 m further into the forests and were more likely to naturalize than animal‐dispersed species. We did not detect relationships between the measured traits and estimated density of naturalized aliens in the adjacent forests.6.Synthesis: Traits were able to differentiate alien species from botanic gardens that naturalized in native forest from those that did not; this is promising for developing trait‐based risk assessment in the tropics. To limit the risk of invasion and spread into adjacent native forests, we suggest tropical botanic gardens avoid planting alien species with fast carbon capture strategies and those that are shade tolerant.
Gut microbial ecology of the Critically Endangered Fijian crested iguana (Brachylophus vitiensis): Effects of captivity status and host reintroduction on endogenous microbiomes
Authors: Eliades Samuel J. , Brown Joseph C. , Colston Timothy J. , Fisher Robert N. , Niukula Jone B. , Gray Kim , Vadada Jhabar , Rasalato Sia , Siler Cameron D. 
Published: March 2021

AbstractAnimals often exhibit distinct microbial communities when maintained in captivity as compared to when in the wild. Such differentiation may be significant in headstart and reintroduction programs where individuals spend some time in captivity before release into native habitats. Using 16S rRNA gene sequencing, we (i) assessed differences in gut microbial communities between captive and wild Fijian crested iguanas (Brachylophus vitiensis) and (ii) resampled gut microbiota in captive iguanas released onto a native island to monitor microbiome restructuring in the wild. We used both cloacal swabs and fecal samples to further increase our understanding of gut microbial ecology in this IUCN Critically Endangered species. We found significant differentiation in gut microbial community composition and structure between captive and wild iguanas in both sampling schemes. Approximately two months postrelease, microbial communities in cloacal samples from formerly captive iguanas closely resembled wild counterparts. Interestingly, microbial communities in fecal samples from these individuals remained significantly distinct from wild conspecifics. Our results indicate that captive upbringings can lead to differences in microbial assemblages in headstart iguanas as compared to wild individuals even after host reintroduction into native conditions. This investigation highlights the necessity of continuous monitoring of reintroduced animals in the wild to ensure successful acclimatization and release.
Mutualism promotes site selection in a large marine planktivore
Authors: Armstrong Asia O. , Armstrong Amelia J. , Bennett Michael B. , Richardson Anthony J. , Townsend Kathy A. , Everett Jason D. , Hays Graeme C. , Pederson Hugh , Dudgeon Christine L. 
Published: March 2021

Abstract

Mutualism is a form of symbiosis whereby both parties benefit from the relationship. An example is cleaning symbiosis, which has been observed in terrestrial and marine environments. The most recognized form of marine cleaning symbiosis is that of cleaner fishes and their clients.

Cleaner species set up cleaning stations on the reef, and other species seek out their services. However, it is not well understood how the presence of cleaning stations influence movements of large highly mobile species. We examined the role of cleaning stations as a driver of movement and habitat use in a mobile client species.

Here, we used a combination of passive acoustic telemetry and in‐water surveys to investigate cleaning station attendance by the reef manta ray Mobula alfredi. We employed a novel approach in the form of a fine‐scale acoustic receiver array set up around a known cleaning area and tagged 42 rays. Within the array, we mapped structural features, surveyed the distribution of cleaner wrasse, and observed the habitat use of the rays.

We found manta ray space use was significantly associated with blue‐streak cleaner wrasse Labroides dimidiatus distribution and hard coral substrate. Cleaning interactions dominated their habitat use at this site, taking precedence over other life history traits such as feeding and courtship.

This study has demonstrated that cleaning symbiosis is a driver for highly mobile, and otherwise pelagic, species to visit inshore reef environments. We suggest that targeted and long‐term use of specific cleaning stations reflects manta rays having a long‐term memory and cognitive map of some shallow reef environments where quality cleaning is provided. We hypothesize that animals prefer cleaning sites in proximity to productive foraging regions.
Environment‐driven changes in diversity of riparian plant communities along a mountain river
Authors: Flores‐Galicia Nihaib , Trejo Irma , Ramírez‐Marcial Neptalí 
Published: March 2021

AbstractThe study of changes in species richness and composition along rivers has focused on large spatial scales. It has been ignored that in different sections of the river (high mountain area, middle zone, and mouth of the river) the specific environmental conditions can generate different longitudinal patterns of the species richness and composition. In this study, we determine whether species richness and composition of the riparian plant communities change along a mountain river and whether these changes are related to environmental variables. We expect an increase in species richness and turnover along the river, that the upstream communities would be a subset of the downstream communities, and that such would be related to edaphic and hydrologic conditions. To test this, we sampled three strata of the riparian vegetation (upper: individuals with <1 cm of ND, middle: individuals with >1 cm of ND, low: individuals with >1 m tall) in a set of 15 sites that we place along a mountain river. Additionally, we recorded topographic, hydrological, morphological, and soil variables. We performed correlation analyzes to determine whether changes in species richness and turnover were related to increased distance to the origin of the river. Also, we obtained the nestedness and evaluated the importance of environmental variables with GLM, LASSO regression, and CCA. With the increase in distance, the species richness decreases in the upper stratum, but not in the middle and the low stratum (although the highest values were observed near the origin of the river), the turnover increase in all strata and the upstream communities were not a subset of the downstream communities. The changes in species richness and composition were related to topographic (altitude), hydrological (flow), and edaphic (conductivity and pH) variables. Our results indicate that at small spatial scales the patterns of richness and composition differ from what has been found at larger spatial scales and that these patterns are associated with environmental changes in the strong altitude gradients of mountain rivers.
Potassium tert‐Butoxide‐Catalyzed Synthesis of α‐Methylene‐β‐Lactams from Propiolamides
Authors: Claus Angelica R. , Goulart Tales A. C. , Back Davi F. , Zeni Gilson 
Published: March 2021

AbstractWe reported herein the regio‐ and stereoselective synthesis of α‐methylene‐β‐lactams via a 4‐exo‐dig‐cyclization of N‐benzyl‐N‐methyl‐propiolamides catalyzed by a base. The experimental evidence suggests that this transformation proceeds via a concerted ionic cyclization with a carbon nucleophilic addition to the carbon‐carbon triple bond, followed by protonation of the vinyl species promoted by tert‐butanol. The obtained α‐methylene‐β‐lactams were suitable substrates for the Heck coupling conditions affording the corresponding products via carbon‐carbon bond formation.
Metal‐Free Direct Oxidative C−N Bond Coupling of Quinoxalin‐2(1H)‐ones with Azoles under Mild Conditions
Authors: Guo Jingwen , Zhang Lina , Du Xinyue , Zhang Liting , Cai Yuepiao , Xia Qinqin 
Published: March 2021

AbstractDirect C3−H amination of quinoxalin‐2(1H)‐ones with azoles under mild conditions promoted by PIFA has been achieved in good yield in a very fast manner. Mechanistic study revealed that the reaction proceeds through a radical process. In addition, this method could be applied to gram‐scale reaction.
Shake‐table tests of innovative drift sensitive nonstructural elements in a low‐damage structural system
Authors: Bianchi Simona , Ciurlanti Jonathan , Perrone Daniele , Filiatrault André , Costa Alfredo Campos , Candeias Paulo X. , Correia António A. , Pampanin Stefano 
Published: March 2021

AbstractPost‐earthquake damage reports have continuously highlighted the significant vulnerability of nonstructural elements to seismic events. Nonstructural damage has severe impact in the building recovery, increasing the socioeconomic losses even for low intensity events. In the last few years, research efforts have focused on the development of innovative nonstructural solutions, to be combined with damage‐resistant structural skeletons in order to obtain an overall high‐performance building. As part of a European Union (EU)‐funded project, the effectiveness of such integrated skeleton&envelope low‐damage system in reducing the earthquake related losses was investigated. Tridimensional shake table tests on a 1:2 scaled timber‐concrete low‐damage structural skeleton, “dressed” by different innovative nonstructural elements (glass/concrete facades, gypsum/masonry partitions), were performed at the National Laboratory for Civil Engineering (LNEC) in Lisbon, Portugal. The shake table tests were carried out at increasing seismic intensities to investigate the structural and nonstructural performance up to a higher‐than Collapse Prevention Limit State according to the Italian Code (975 years return period). This paper focuses on the dynamic behavior of nonstructural elements with detailed discussion on construction detailing, seismic demand and performance of the innovative solutions. The high performance of nonstructural elements proved the potential of the details introduced in the partitions/facades. Minimal or no damage was observed up to the end of the overall testing sequence, which reached moderate‐to‐high interstory drift ratios (more than 1.00%) ‐ typically expected to cause severe damage to traditional nonstructural partitions/infills/facades.
Value‐aware cache replacement in edge networks for Internet of Things
Authors: Peng Ting , Wang Haohao , Liang Cangming , Dong Pingping , Wei Yehua , Yu Jianping , Zhang Lianming 
Published: March 2021

AbstractWith the development of Internet of Things (IoT), massive amounts of data will be brought. By offloading caching from the cloud to the edge, edge caching technology represents a promising solution in the era of IoT to meet the delay requirements of IoT applications. An efficient cache decision and replacement strategy on edge caching devices is a key factor in ensuring the cache hit ratio. The existing cache replacement policies do not comprehensively consider the characteristics of cache files and are likely to result in cache pollution problems. In order to cache data reasonably, to improve the cache hit ratio, and to reduce the user request delay, we propose a concept of file cache value and a file cache value‐aware cache replacement (FCVACR) algorithm of the edge cache system in this article. File cache value is associated with three aspects of cache file: the file size, the file popularity, and the time of requests. The proposed FCVACR algorithm adopts the file cache value method, improves the utilization of edge caching space, and reduces the content transmission delay. Experimental results show that the proposed FCVACR algorithm has a higher cache hit ratio and lower user request delay than the classical cache replacement algorithms.
Effects of investor attention in China's commodity futures markets
Authors: Wu Ming‐Hung , Tsai Wei‐Che , Weng Pei‐Shih , Li Dan‐Yi 
Published: March 2021

AbstractThis paper analyzes the impacts of investor attention on the returns and volatility of commodity futures in China. Using online search volumes as a proxy for investor attention, we find that investor attention exhibits a positive contemporaneous relationship with returns and volatility. In addition, the online search variables are significant predictors of returns and volatility in the commodity futures markets. Moreover, as compared with personal computer searches, mobile searches have a more pronounced predictive effect on returns and volatility. Taken together, we suggest that investor attention can explain the concurrent price movement and variation in the commodity futures markets in China.