bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Lead Halide Perovskites to Lead‐Free Metal Halide Perovskites and Perovskite Derivatives
Authors: Xiao Zewen , Song Zhaoning , Yan Yanfa 
Published: January 2019

AbstractDespite the exciting progress on power conversion efficiencies, the commercialization of the emerging lead (Pb) halide perovskite solar cell technology still faces significant challenges, one of which is the inclusion of toxic Pb. Searching for Pb‐free perovskite solar cell absorbers is currently an attractive research direction. The approaches used for and the consequences of Pb replacement are reviewed herein. Reviews on the theoretical understanding of the electronic, optical, and defect properties of Pb and Pb‐free halide perovskites and perovskite derivatives are provided, as well as the experimental results available in the literature. The theoretical understanding explains well why Pb halide perovskites exhibit superior photovoltaic properties, but Pb‐free perovskites and perovskite derivatives do not.
Synthesis of (2H)‐Indazoles from Azobenzenes Using Paraformaldehyde as a One‐Carbon Synthon
Authors: Chun Rina , Kim Saegun , Han Sang Hoon , Han Sangil , Lee Suk Hun , Mishra Neeraj Kumar , Jung Young Hoon , Kim Hyung Sik , Kim In Su 
Published: January 2019

AbstractRhodium(III)‐catalyzed hydroxymethylation followed by intramolecular annulation of azobenzenes using paraformaldehyde as a valuable C1‐feedstock is described. The method is readily extended to the coupling reaction between azobenzenes and trifluoroacetaldehyde. This transformation efficiently produces a range of C3‐unsubstituted and C3‐trifluoromethylated (2H)‐indazoles, which are important targets in the development of novel bioactive compounds. Excellent chemoselectivity and functional group tolerance were observed. The synthetic transformation of C3‐unsubstituted (2H)‐indazoles highlights the utility of the developed method.magnified image
Recent Progress in Catalytic Oxidative Transformations of Alcohols by Supported Gold Nanoparticles
Authors: Hui Yonghai , Zhang Shiqi , Wang Wentao 
Published: January 2019

AbstractCatalytic oxidative transformations of alcohols constitute one of the greatly important protocols for the synthesis of various aldehydes, ketones, acids, imines, amides, etc. that are required to make drug intermediates, food additives, plastics, detergents and cosmetics. The potential of gold nanoparticles (Au NPs) in catalytic oxidation reactions is generally competent owing to their tendency to activate oxygen. Supports play a conspicuous and increasingly important role not only in the preparation and stabilization of Au NPs, but also can address the issues of sustainability by facilitating separation and reusability of the catalyst. This review aims to systematically discuss the impressive developments in catalytic oxidative transformations of alcohols promoted by supported Au NPs in the last five years. These Au NPs exhibit unique electronic properties and crystal structures, which gives us an excellent opportunity to correlate atomic structure with intrinsic catalytic properties over Au NPs. The effect of a support on the significant properties of Au NPs in terms of catalytic activity, selectivity, recyclability, and stability is discussed at length. The tentative reaction mechanisms and the structure‐performance relationships are also discussed at appropriate places, which will provide some clues for the design of efficient Au NPs‐based catalysts.magnified image
Revisiting Primary Particles in Layered Lithium Transition‐Metal Oxides and Their Impact on Structural Degradation
Authors: Lee Seung‐Yong , Park Gyeong‐Su , Jung Changhoon , Ko Dong‐Su , Park Seong‐Yong , Kim Hee Goo , Hong Seong‐Hyeon , Zhu Yimei , Kim Miyoung 
Published: January 2019

AbstractLayered lithium transition‐metal oxide materials, e.g., Li(Ni1−x−yCoxMny)O2 (NCM) and Li(Ni1−x−yCoxAly)O2, are the most promising candidates for lithium‐ion battery cathodes. They generally consist of ≈10 µm spherical particles densely packed with smaller particles (0.1–1 µm), called secondary and primary particles, respectively. The micrometer‐ to nanometer‐sized particles are critical to the battery performance because they affect the reaction capability of the cathode. Herein, the crystal structure of the primary particles of NCM materials is revisited. Elaborate transmission electron microscopy investigations reveal that the so‐called primary particles, often considered as single crystals, are in fact polycrystalline secondary particles. They contain low‐angle and exceptionally stable special grain boundaries (GBs) presumably created during aggregation via an oriented attachment mechanism. Therefore, this so‐called primary particle is renamed as primary‐like particle. More importantly, the low‐angle GBs between the smaller true primary particles cause the development of nanocracks within the primary‐like particles of Ni‐rich NCM cathodes after repetitive electrochemical cycles. In addition to rectifying a prevalent misconception about primary particles, this study provides a previously unknown but important origin of structural degradation in Ni‐rich layered cathodes.
Nature Driven Bio‐Piezoelectric/Triboelectric Nanogenerator as Next‐Generation Green Energy Harvester for Smart and Pollution Free Society
Authors: Maiti Sandip , Karan Sumanta Kumar , Kim Jin Kon , Khatua Bhanu Bhusan 
Published: January 2019

AbstractElectronics wastes (e‐wastes) are the major concern in the rapid expansion of smart/wearable/portable electronics in modern high‐tech society. Informal processing and enormous gathering of e‐wastes can lead to adverse human/animal health effects and environmental pollution worldwide. Currently, these issues are a big headache and require the scientific community to develop effective green energy harvesting technologies using biodegradable/biocompatible materials. Piezoelectric/triboelectric nanogenerators (PNGs/TNGs) are considered one of the most promising renewable green energy sources for the conversion of mechanical/biomechanical energies into electricity. However, organic/inorganic material based PNGs/TNGs are very much incompatible, and considered e‐wastes for their non‐biodegradability. This review covers potential uses of biodegradable/biocompatible materials which are wasted every day as nature driven material based bio‐nanogenerators with a particular focus on their applications in flexible PNGs/TNGs fabrication. Structural investigation and possible working principles are described first in order to outline the basic mechanism of bio‐inspired materials behind energy harvesting. Then, energy harvesting abilities and the mechanical sensing of bio‐inspired integrated flexible devices are discussed under various mechanical/biomechanical activities. Finally, their potential applications in various flexible, wearable, and portable electronic fields are demonstrated. These bio‐inspired energy harvesting devices can make huge changes in fields as diverse as portable electronics, in vitro/in vivo biomedical applications, and many more.
Construction of Hierarchical K1.39Mn3O6 Spheres via AlF3 Coating for High‐Performance Potassium‐Ion Batteries
Authors: Zhao Shuoqing , Yan Kang , Munroe Paul , Sun Bing , Wang Guoxiu 
Published: January 2019

AbstractPotassium‐ion batteries are attracting great interest for emerging large‐scale energy storage owing to their advantages such as low cost and high operational voltage. However, they are still suffering from poor cycling stability and sluggish thermodynamic kinetics, which inhibits their practical applications. Herein, the synthesis of hierarchical K1.39Mn3O6 microspheres as cathode materials for potassium‐ion batteries is reported. Additionally, an effective AlF3 surface coating strategy is applied to further improve the electrochemical performance of K1.39Mn3O6 microspheres. The as‐synthesized AlF3 coated K1.39Mn3O6 microspheres show a high reversible capacity (about 110 mA h g−1 at 10 mA g−1), excellent rate capability, and cycling stability. Galvanostatic intermittent titration technique results demonstrate that the increased diffusion kinetics of potassium‐ion insertion and extraction during discharge and charge processes benefit from both the hierarchical sphere structure and surface modification. Furthermore, ex situ X‐ray diffraction measurements reveal that the irreversible structure evolution can be significantly mitigated via surface modification. This work sheds light on rational design of high‐performance cathode materials for potassium‐ion batteries.
Isocyanide‐Based Multicomponent Reactions: A Concise Approach to 2‐Amino‐3‐perfluoroalkylfurans Using Methyl Perfluoroalk‐2‐ynoates as Fluorinated Building Blocks
Authors: Wang Yedong , Tao Lili , Chen Jie , He Weimin , Deng Hongmei , Shao Min , Zhang Hui , Cao Weiguo 
Published: January 2019

AbstractSynthesis of 2‐amino‐3‐perfluoroalkylfurans has been accomplished by isocyanide‐based multicomponent reactions. Using methyl perfluoroalk‐2‐ynoates as the fluorinated build blocks in combination with isocyanides and aromatic aldehydes in one‐pot at room temperature, the perfluoroalkyl‐substituted 2‐aminofurans were obtained in good to excellent yields.
Synthesis of cardanol‐based phthalonitrile monomer and its copolymerization with phenol–aniline‐based benzoxazine
Authors: Chen Yu‐Peng , Dayo Abdul Qadeer , Zhang Hui‐Yan , Wang An‐ran , Wang Jun , Liu Wen‐bin , Yang Yan , Qin Qi‐Rui , Yang Yu‐Gang 
Published: January 2019

ABSTRACTThe cardanol‐based phthalonitrile (PN) monomer was successfully produced via the nucleophilic substitution reaction of cardanol with 4‐nitrophthalonitrile in potassium carbonate media. The conventional methods were employed to predict the chemical structure. The influence of long alkyl chains of cardanol was observed on the thermomechanical properties, recorded values were much below than the poly(Baph) standards. However, the thermal stabilities were recorded in good agreement to PN resin values. Furthermore, the 100 kGy dose of Co60 irradiation does not show any remarkable changes in the studied properties. The copolymers from P‐a benzoxazine and cardanol‐based PN (CPN) on the different wt % blending were prepared. The curing behavior and mechanism of the monomer blends were analyzed. The curing of CPN was improved in the presence of active hydrogen produced from the P‐a polymerization. The T
g and thermal properties of the copolymer were much better than the neat poly(P‐a). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47505.
Synthesis and Investigation of Phthalazinones as Antitubercular Agents
Authors: Santoso Kristiana T. , Cheung Chen‐Yi , Hards Kiel , Cook Gregory M. , Stocker Bridget L. , Timmer Mattie S. M. 
Published: January 2019

AbstractA series of 2‐ and 7‐substituted phthalazinones was synthesised and their potential as anti‐tubercular drugs assessed via Mycobacterium tuberculosis (mc26230) growth inhibition assays. All phthalazinones tested showed growth inhibitory activity (MIC <100 μm), and those compounds containing lipophilic and electron‐withdrawing groups generally exhibited better anti‐tubercular activity. Several lead compounds were identified, including 7‐((2‐amino‐6‐(4‐fluorophenyl)pyrimidin‐4‐yl)amino)‐2‐heptylphthalazin‐1(2H)‐one (MIC=1.6 μm), 4‐tertbutylphthalazin‐2(1H)‐one (MIC=3 μm), and 7‐nitro‐phthalazin‐1(2H)‐one (MIC=3 μm). Mode of action studies indicated that selected pyrimidinyl‐phthalazinones may interfere with NADH oxidation, however, the mode of action of the lead compound is independent of this enzyme. MIC=minimum inhibitory concentration.
Dermoscopic clues in the skin lesions of secondary syphilis
Authors: Mathur Mahesh , Acharya Prakash , Karki Alina , Shah Jyoti , KC Nisha 
Published: January 2019

Key Clinical MessageSecondary syphilis may have a varied clinical presentation and might pose a diagnostic difficulty when a typical history is absent. We describe the dermoscopic clues of the skin lesions at different stages of the disease which could culminate to a proper diagnosis.
Highly Active and Stable Carbon Nanosheets Supported Iron Oxide for Fischer‐Tropsch to Olefins Synthesis
Authors: Zhou Yunyun , Natesakhawat Sittichai , Nguyen‐Phan Thuy‐Duong , Kauffman Douglas R. , Marin Chris M. , Kisslinger Kim , Lin Ruoqian , Xin Huolin L. , Stavitski Eli , Attenkofer Klaus , Tang Yijie , Guo Yisong , Waluyo Iradwikanari , Roy Amitava , Lekse Jonathan W. , Yu Yang , Baltrus John , Lu Yu , Matranga Christopher , Wang Congjun 
Published: January 2019

AbstractLight olefins production utilizes the energy intensive process of steam cracking. Fischer‐Tropsch to olefins (FTO) synthesis potentially offers a more sustainable alternative. Here we show a promising FTO catalyst comprised of iron oxide nanoparticles supported on carbon nanosheets (CNS) fabricated from the carbonization of potassium citrate, which incorporates well dispersed K‐promoter throughout the CNS support. This catalyst exhibits, to the best of our knowledge, the highest iron time yield of 1790–1990 μmolCO/gFe ⋅ s reported in the literature, 41 % light olefins selectivity, and over 100 hours stable activity, making it one of the best performing FTO catalysts. Detailed characterization illustrates that the CNS support facilitates iron oxide reduction to metallic iron, leading to efficient transformation to the active iron carbide phase during FTO reaction. Since K is a commonly used promoter, our K‐promoted CNS support potentially has broad utility beyond the FTO reactions demonstrated in the current study.
Carbon‐Derived Supports for Palladium Nanoparticles as Catalysts for Carbon‐Carbon Bonds Formation
Authors: Gholinejad Mohammad , Naghshbandi Zhwan , Nájera Carmen 
Published: January 2019

AbstractThe review considers the variety allotropes of carbon to be used as supports for palladium and investigation of the resulting catalysts for carbon‐carbon forming reactions with focus on the catalyst recovery and effect of the solvent, base and catalyst loading in the efficiency of reactions. Specially, carbon nanotubes, C60 and graphene allowed the covalent functionalization with different ligands for palladium facilitating a lower leaching. Magnetic iron nanoparticles can be easily covered by charcoal, graphene oxide and carbon quantum dots facilitating the recovery of the supported catalyst. These heterogeneous catalysts are able to activate even aryl chlorides in cross‐coupling reactions such as Suzuki‐Miyaura, Mizoroki‐Heck and Sonogashira‐Hagihara in organic but also in aqueous media. All these features favoured the applicability of the materials for industrial processes.
Matrix Coordination Induced Emission in a Three‐Dimensional Silver Cluster‐Assembled Material
Authors: Wei Zhong , Wu Xiao‐Hui , Luo Peng , Wang Jia‐Yin , Li Kai , Zang Shuang‐Quan 
Published: January 2019

AbstractInvited for the cover of this issue is the group of Kai Li and Shuang‐Quan Zang at Zhengzhou University. The image depicts how the quantum yield of an organic ligand is enhanced through immobilization in a rigid MOF containing silver–chalcogenolate clusters. Read the full text of the article at 10.1002/chem.201805381.
MicroRNAs 342 and 450 together with NOX‐4 activity and their association with coronary artery disease in diabetes
Authors: Seleem Mae , Shabayek Marwa , Ewida Heba A. 
Published: January 2019

AbstractBackgroundDysregulation of miRNAs has been associated with many clinical conditions, including coronary artery disease (CAD). MiRNAs roles in patients with type 2 diabetes mellitus (T2D) with or without CAD, however, have not been clearly understood. Therefore we studied the expression of miRNAs 342 and 450 and the activity of the NADPH oxidase 4 (NOX‐4), and their association with anthropometric and biochemical parameters of hyperglycaemia and dyslipidaemia.Subjects and MethodsBlood was collected from 200 outpatient subjects, divided into four groups of 50 individuals including control, T2D, CAD, and T2D with CAD. CAD was further divided based on CAD with angina, CAD clots, and CAD ischaemia to differentiate the primary cause of CAD. We measured the miRNAs 342 and 450 expression and NOX‐4 activity, in addition to routine parameters.ResultsThe expression of miRNAs 342 and 450 and NOX‐4 activity was significantly different between groups. Furthermore, they presented significant correlations with routine parameters, providing evidence of a potentially beneficial role in stratifying the risk for CAD in patients with T2D.ConclusionThe results of this study suggest that the expression of miRNAs 342 and 450 and NOX‐4 activity may help identify those individuals with T2D at high risk for developing CAD as well as the prognosis in those with established CAD.
Asymmetric introgression between fishes in the Red River basin of Texas is associated with variation in water quality
Authors: Alex Sotola V. , Ruppel David S. , Bonner Timothy H. , Nice Chris C. , Martin Noland H. 
Published: January 2019

AbstractWhen ecologically divergent taxa encounter one another, hybrid zones can form when reproductive isolation is incomplete. The location of such hybrid zones can be influenced by environmental variables, and an ecological context can provide unique insights into the mechanisms by which species diverge and are maintained. Two ecologically differentiated species of small benthic fishes, the endemic and imperiled prairie chub,Macrhybopsis australis, and the shoal chub,Macrhybopsis hyostoma, are locally sympatric within the upper Red River Basin of Texas. We integrated population genomic data and environmental data to investigate species divergence and the maintenance of species boundaries in these two species. We found evidence of advanced‐generation asymmetric hybridization and introgression, with shoal chub alleles introgressing more frequently into prairie chubs than the reciprocal. Using a Bayesian Genomic Cline framework, patterns of genomic introgression were revealed to be quite heterogeneous, yet shoal chub alleles were found to have likely selectively introgressed across species boundaries significantly more often than prairie chub alleles, potentially explaining some of the observed asymmetry in hybridization. These patterns were remarkably consistent across two sampled geographic regions of hybridization. Several environmental variables were found to significantly predict individual admixture, suggesting ecological isolation might maintain species boundaries.
Seed germination responses to seasonal temperature and drought stress are species‐specific but not related to seed size in a desert steppe: Implications for effect of climate change on community structure
Authors: Yi Fengyan , Wang Zhaoren , Baskin Carol C. , Baskin Jerry M. , Ye Ruhan , Sun Hailian , Zhang Yuanyuan , Ye Xuehua , Liu Guofang , Yang Xuejun , Huang Zhenying 
Published: January 2019

AbstractInvestigating how seed germination of multiple species in an ecosystem responds to environmental conditions is crucial for understanding the mechanisms for community structure and biodiversity maintenance. However, knowledge of seed germination response of species to environmental conditions is still scarce at the community level. We hypothesized that responses of seed germination to environmental conditions differ among species at the community level, and that germination response is not correlated with seed size. To test this hypothesis, we determined the response of seed germination of 20 common species in the Siziwang Desert Steppe, China, to seasonal temperature regimes (representing April, May, June, and July) and drought stress (0, −0.003, −0.027, −0.155, and −0.87 MPa). Seed germination percentage increased with increasing temperature regime, but Allium ramosum, Allium tenuissimum, Artemisia annua, Artemisia mongolica, Artemisia scoparia, Artemisia sieversiana, Bassia dasyphylla, Kochia prastrata, and Neopallasia pectinata germinated to >60% in the lowest temperature regime (April). Germination decreased with increasing water stress, but Allium ramosum, Artemisia annua, Artemisia scoparia, Bassia dasyphylla, Heteropappus altaicus, Kochia prastrata, Neopallasia pectinata, and Potentilla tanacetifolia germinated to near 60% at −0.87 MPa. Among these eight species, germination of six was tolerant to both temperature and water stress. Mean germination percentage in the four temperature regimes and the five water potentials was not significantly correlated with seed mass or seed area, which were highly correlated. Our results suggest that the species‐specific germination responses to environmental conditions are important in structuring the desert steppe community and have implications for predicting community structure under climate change. Thus, the predicted warmer and dryer climate will favor germination of drought‐tolerant species, resulting in altered proportions of germinants of different species and subsequently change in community composition of the desert steppe.
Variation in spawning phenology within salmon populations influences landscape‐level patterns of brown bear activity
Authors: Deacy William W. , Leacock William B. , Stanford Jack A. , Armstrong Jonathan B. 
Published: January 2019

AbstractAnimal consumers track spatial variation in resource phenology (i.e., resource waves) to prolong their access to ephemeral foods. While recent work has revealed how animals move across landscapes to exploit phenological variation among discrete foraging patches, much less is known about how variation nested within patches influences the spatiotemporal pattern of foraging opportunities and the behavior of consumers. Local, within‐patch, variation in phenology influences levels of resource ephemerality and could dictate how frequently consumers must move to continuously exploit a pulsed food source. Here, we explore how within‐site (stream) phenological variation relates to the duration of salmon (Oncorhynchus nerka) runs and its consequences for brown bear (Ursus arctos middendorffi) foraging behavior. We accurately quantified salmon run duration across a large number of spawning streams (21 site‐year combinations). We found that salmon run duration varied threefold among spawning sites and that the source of prolonged runs was within‐site variation in spawning phenology (i.e., the timing of arrival at spawning grounds). Although the estimated reproductive lifespan varied among sites, a simulation suggested that reproductive lifespan has little influence on salmon run duration. Salmon run duration strongly predicted the duration of site occupancy by bears, demonstrating that phenological variation within salmon populations compliments among‐population variation to alleviate time constraints on salmon consumption. To explore whether within‐population variation in salmon phenology was related to spatial variation in habitat conditions (as is the case with among‐population phenological variation), we monitored water temperature, salmon availability, and bear activity across a longitudinal gradient in Connecticut Creek, the study stream with the most prolonged salmon run. Spawn timing varied spatially, occurring first in cold headwater reaches and later in warmer downstream reaches. Patterns of bear presence closely tracked this spawning sequence, suggesting they “surf salmon waves” not only across landscapes but also within spawning sites. However, a coarser analysis across multiple sites suggests phenological variation within salmon populations may not always be spatially structured. Our results demonstrate one way in which local variation in phenology can influence consumer foraging behavior, highlighting the need to understand the causes and consequences of phenological variation at multiple scales.