bluuebunny/crossref_metadata_2025_split huggingface dataset:
Post‐Permian Radiation
Authors: Foster William J , Twitchett Richard J 
Published: April 2021

Abstract

The post‐Permian radiation is the diversification of the modern evolutionary fauna in the aftermath of the end‐Permian mass extinction. This radiation was ‘delayed’ due to the magnitude of species loss, persistent environmental stress and subsequent biotic crises associated with the extinction event. Investigating the post‐Permian radiation is, however, confounded by issues with the quality of the Early Triassic fossil record. Since the low level of post‐extinction diversity has not been recorded since the Ordovician, an expectation is that the post‐Permian radiation would record large‐scale adaptations and the evolution of novel body plans. Globally, however, the extinction did not cause a reduction in the number of ecological lifestyles, and the post‐Permian radiation was seeded by an ecological diverse group of survivors. Groups that radiated into vacant ecospace include the bivalves, which diversified to dominate benthic habitats; the Scleractinia, which replaced the Palaeozoic reef‐building metazoans and the reptiles that became top marine predators.

Our understanding of the post‐Permian radiation is hampered by the poor Early Triassic fossil record.

The end‐Permian mass extinction event is the most severe extinction event known from the fossil record.

The post‐Permian radiation was delayed due to ecological and environmental changes associated with the mass extinction event.

The mass extinction did not cause the extinction of ecological lifestyles, and the post‐Permian radiation was at low taxonomic levels.

The post‐Permian radiation caused a marked change in the evolutionary trajectory of almost all animal groups and led to fundamental changes in the functioning of marine ecosystems.
Ecological Character Displacement
Authors: Grant Peter R 
Published: April 2021

Abstract

Some morphological differences between closely related species living in the same environment have been enhanced by natural selection resulting from competition for resources or from negative effects of interbreeding. These evolutionary changes are known as ecological and reproductive character displacement, respectively. Ecological character displacement helps us to understand how complex communities are built up from simpler ones through ecological adjustments of the constituent species. It also may be involved in the late stages in speciation when formerly allopatric populations come together in sympatry. There are few cases of ecological character displacement in nature where the evidence is sufficiently strong to demonstrate evolution by natural selection and to rule out alternative explanations of the causes. These have been supplemented by experiments: there is scope and need for more.

Key Concepts

Character displacement is a process of evolutionary divergence of coexisting species.

Competition for resources, such as food, gives rise to natural selection.

Competition is reduced as a result of character displacement.

Closely related species differ in morphology more in sympatry than in allopatry.

Experiments attempt to recreate conditions that are conducive to character displacement in nature.

Solitary species are released from competition and broaden their ecological niches.

Character displacement helps to explain how complex communities of potential competitors develop from simple ones.

Character displacement is one of several types of evolutionary adjustments made by coexisting species.

Its signature should be seen most clearly in young adaptive radiations.

The main question about character displacement is not whether it occurs but how important it is.
Biotic Recoveries from Mass Extinction Events
Authors: Darroch Simon AF 
Published: April 2021

Abstract

The recoveries following mass extinctions are prolonged (∼10
4
–10
6
years) intervals characterised by recovering biodiversity and rapid turnover in community composition, along with a more gradual re‐establishment of Earth systems functioning – a process termed ‘Earth systems succession’. Recent data reveal that recovery intervals differ substantially between the ‘Big Five’ mass extinction events and are typically biogeographically complex, with substantial differences in rates of taxonomic and ecological recovery among different biological groups, environments and latitudes. Although there is some suggestion that the duration of recovery intervals is controlled by environmental factors (e.g. local persistence of the extinction triggers themselves), other work instead hints at ecological interactions and community dynamics as dominant influences. The recovery intervals following a small number of mass extinction events lead to permanent macroecological and ‐evolutionary changes, thus profoundly influencing the history of life and leaving a unique signature in the present‐day structure of the biosphere.

Key Concepts

The ‘Big 5’ mass extinctions had unique sets of extinction triggers and drivers, which produced unique patterns of extinction selectivity and thus unique patterns of recovery in the aftermath.

Recovery from mass extinction can be measured either in terms of raw diversity or in terms of ecosystem structure/function. These two facets of recovery can be decoupled.

Recovery intervals are characterised by rapid turnover in community composition; the structure and composition of these communities can, in turn, affect and control recovering Earth systems functioning.

Rates and patterns of recovery are typically highly heterogeneous, with substantial differences between taxonomic groups, environments and geographic location.

Recovery intervals following a few specific mass extinction events coincided with fundamental and permanent changes in macroecological and ‐evolutionary patterns.
Novel Authentic and Ultrafast Organic Photorecorders Enhanced by AIE‐Active Polymer Electrets via Interlayer Charge Recombination
Authors: Ke Chun‐Yao , Chen Mei‐Nung , Chen Mu‐Huai , Li Yen‐Ting , Chiu Yu‐Cheng , Liou Guey‐Sheng 
Published: April 2021

AbstractOrganic photonic memory, featuring a variety of glamorously light‐driven characteristics, is rapidly growing into an indispensable building block for next‐generation optical communication systems. However, the ambiguity of their operating mechanism associated with the limitation of photoadaptive materials as an electronics promoter results in the slow development of photonic transistor‐based devices. In this study, the conjugated polymers composed of donor–acceptor motifs with typical aggregation‐induced emission (AIE) behaviors are designed and successfully discover high‐performance photoprogrammable memory. Moreover, the mechanism of photoboosted recording behavior, attributed to the recombination of the formed interlayer excitons right after simultaneous excitation without applying vertical and parallel electric‐field at the interface in‐between active semiconductor and AIE polymers, is cautiously corroborated by steady‐state PL and pulse PL measurements. The AIE‐polymer memory devices perform ultrafast photoresponse time of 0.1 ms, an outstanding current switch ratio up to 106, and retention stability over 40 000 s without significant dissipation. Furthermore, photoresponsive AIE‐polymer electrets not only modulate the memory performance through the emission wavelength but easily switch storage behavior of nonvolatile memory from flash to WORM by adjusting the torsion‐angle through the motif of the donor and acceptor moieties. These findings open an avenue for designing conjugated polymer electret for ultrafast optical storage devices.
Highly Luminescent and Patternable Block Copolymer Templated 3D Perovskite Films
Authors: Li Chongyuan , Chen Yu , Liu Fengcai , Liu Kai , Li Xiaoguo , Zhang Xin , Zhang Haijuan , Shi Zejiao , Chen Wei , Ahmed Irfan , Arshid Numan , Wang Jiao , Sun Zhengyi , Xiong Shisheng , Zhan Yiqiang 
Published: April 2021

AbstractThe rapid development of lead halide perovskite light emitting diodes (PeLED) provides bright prospects for future lighting and display applications. However, the lack of efficient blue light emission, the insufficient device stability, and the shortage of convenient patterning methods greatly impede the development of PeLED applications. In this work, a feasible two‐step fabrication method combined with a block copolymer (BCP) template is introduced to fabricate high quality CH3NH3PbBrxCl3−x 3D perovskite film. The BCP‐templated CH3NH3PbBr3 film possesses a state‐of‐the‐art photoluminescence quantum yield (PLQY) of 62% in the champion sample (58% average PLQY) and an outstanding stability at room temperature. Using halide‐free lead acetate trihydrate as the lead source, the color of the photoluminescence can be tuned easily from green to blue by simply controlling the Cl/Br ratio in the second step. A sky‐blue emission is obtained from a CH3NH3PbBr1.5Cl1.5 perovskite film with a PLQY of 23 ± 2%. The two‐step fabrication approach can also enable straightforward patterning, as demonstrated with inkjet printing and Chinese calligraphy.
Controlled‐release urea improved cotton productivity and nitrogen use efficiency in China: A meta‐analysis
Authors: Tian Xiaofei , Fan Zhen , Zhao Youxin , Sun Shuchen , Li Tingting , Yu Na , Zhai Sheng 
Published: April 2021

AbstractThe use of controlled‐release urea (CRU) is recommended to improve crop productivity without compromising environmental quality, but the overall effects on cotton (Gossypium hirsutum L.) growth are not well studied. A meta‐analysis was conducted to evaluate the effectiveness and potential role of CRU in improving cotton productivity in China. The results indicated that CRU increased cotton yield by 9.8% and nitrogen use efficiency (NUE) by 19.4% relative to urea at equal N rates, although the increase in yield was not statistically significant. Cotton yield increases were greater in sandy‐textured soil than in loam or clay soil, and in experiments sustained for more than 2 yr than in experiments sustained for 1 yr. In addition, the increase in NUE with CRU was enhanced at medium (170 < N ≤ 220 kg N ha−1) and high N rates (>220 kg N ha−1), at high CRU blending ratios (≥70%) and in soils with pH >7.5. These results demonstrate that CRU should be more widely used for cotton production in China, especially in sandy‐textured soil with increased N application.
Paraxial Propagation Properties of Radially Polarized Odd‐Pearcey Gaussian Beams in Free Space
Authors: Fang Mingyue , Liao Xiang , Zhao Jiajia , Xu Chuangjie , Zhang Yixiao , Wu You , Deng Dongmei 
Published: April 2021

AbstractA new type of radially polarized odd‐Pearcey Gaussian beam (RPOPGB) whose paraxial propagation in free space is studied analytically and numerically, is introduced. Intriguingly, the energy of RPOPGBs is found to auto‐focus several times with the Gaussian beam waist radius increasing to some certain extents. Furthermore, RPOPGBs exhibit a special transversal intensity distribution that has an optical trap in the center. During the propagation, at first the RPOPGBs' two main lobes auto‐focus toward the center with side lobes, and then the two main lobes separate after the end of auto‐focusing. The Poynting vectors prove that the energy variation of the lobes maintains excellent central symmetry throughout the propagation. In addition, the fractional vortices are observed from the angular momentum and phase. These findings will be of potential use to particle capture.
Novel Anthracycline Utorubicin for Cancer Therapy
Authors: Simón‐Gracia Lorena , Sidorenko Valeria , Uustare Ain , Ogibalov Ivan , Tasa Andrus , Tshubrik Olga , Teesalu Tambet 
Published: April 2021

AbstractNovel anticancer compounds and their precision delivery systems are actively developed to create potent and well‐tolerated anticancer therapeutics. Here, we report the synthesis of a novel anthracycline, Utorubicin (UTO), and its preclinical development as an anticancer payload for nanocarriers. Free UTO was significantly more toxic to cultured tumor cell lines than the clinically used anthracycline, doxorubicin. Nanoformulated UTO, encapsulated in polymeric nanovesicles (polymersomes, PS), reduced the viability of cultured malignant cells and this effect was potentiated by functionalization with a tumor‐penetrating peptide (TPP). Systemic peptide‐guided PS showed preferential accumulation in triple‐negative breast tumor xenografts implanted in mice. At the same systemic UTO dose, the highest UTO accumulation in tumor tissue was seen for the TPP‐targeted PS, followed by nontargeted PS, and free doxorubicin. Our study suggests potential applications for UTO in the treatment of malignant diseases and encourages further preclinical and clinical studies on UTO as a nanocarrier payload for precision cancer therapy.
Mixed‐Valence Compounds as Polarizing Agents for Overhauser Dynamic Nuclear Polarization in Solids**
Authors: Gurinov Andrei , Sieland Benedikt , Kuzhelev Andrey , Elgabarty Hossam , Kühne Thomas D. , Prisner Thomas , Paradies Jan , Baldus Marc , Ivanov Konstantin L. , Pylaeva Svetlana 
Published: April 2021

AbstractHerein, we investigate a novel set of polarizing agents—mixed‐valence compounds—by theoretical and experimental methods and demonstrate their performance in high‐field dynamic nuclear polarization (DNP) NMR experiments in the solid state. Mixed‐valence compounds constitute a group of molecules in which molecular mobility persists even in solids. Consequently, such polarizing agents can be used to perform Overhauser‐DNP experiments in the solid state, with favorable conditions for dynamic nuclear polarization formation at ultra‐high magnetic fields.
Molecular Weight Engineering in High‐Performance Ambipolar Emissive Mesopolymers
Authors: Guo Xiaofei , Zhang Yihan , Hu Yongxu , Yang Jiaxin , Li Yang , Ni Zhenjie , Dong Huanli , Hu Wenping 
Published: April 2021

AbstractMesopolymers with high solubility, free of structural defects, and negligible batch‐to‐batch variation open a new avenue for organic optoelectronics. Organic light emitting transistors that combine the functions of organic light‐emitting diodes and organic field‐effect transistors. However, charge transport ability and light emitting strength are contradictory within one conjugated polymer. Herein, three low‐molecular‐weight mesopolymers with thienopyrroledione–benzothiadiazole repeating units (meso‐TBTF) were obtained. The mesopolymers show strong solid‐state emission and high ambipolar carrier mobility. The molecular weights of meso‐TBTF can be tuned by polymerization temperature. The mesopolymers have photoluminescence quantum yields (PLQY) of about 50 % in solution and 10 % in solid state. Polymer light emitting diodes of this material are fabricated to explore its potential use in optoelectronic devices.
Microstructural, mechanical and tribological performances of copper foam modified CFRP composite for pantograph strip
Authors: Wang Pei , Jia Yunchao , Li Yilong , Liu Yanyan , Hao Zhenhua , Deng Guanyu , Wang Long 
Published: April 2021

AbstractA novel pantograph strip of copper mesh modified carbon fiber reinforced polymer (CFRP) composite was fabricated by impregnating copper foam with the resin mixture of carbon fiber and flaky graphite, following by mold hot‐pressing technology. Microstructure, mechanical strength, electric conductivity, friction, and wear behaviors of the composite were investigated and analyzed to explore the fracture failure and wear mechanisms. The results show that the composite obtains much lower electric resistance than that of the pure carbon strip used in China's high‐speed railway. Adding carbon fiber can improve impact strength and wear resistance considerably, but has little effect on anti‐friction performance. The electric resistance and tribological performances are graphite dependent, reduced electric resistance and friction coefficient can be obtained with the increase of flaky graphite from 0 to 15 wt% while negligible changes of impact strength and wear rate are found. However, further increasing the flaky graphite to 20 wt%, the wear rate reveals a dramatic rise. High content of flaky graphite contributes to the formation of thick tribolayer with unconsolidated structure. And the tribolayer is easy to curl and worn off from the wear surface, leading to severe wear of the composite during the current carrying friction tests.
Air‐breathing ecology ofArapaimasp.: Conservation implications for an imperilled fish
Authors: Stokes Gretchen L. , Castello Leandro , Petersen Thiago A. , Cooke Steven J. , Power Michael , Zuanon Jansen , Martins Eduardo G. 
Published: April 2021

AbstractArapaima (Arapaimasp.) are highly overexploited fish endemic to the Amazon basin. Because the fish are obligate air‐breathers, it is possible to use surface‐breathing events to count individuals visually for population censuses important for conservation, yet uncertainties remain about body size and environmental influences on air‐breathing intervals, and thus count accuracy.This study examined relationships between breathing intervals and environmental parameters (e.g. water temperature and transparency) and body size for radio‐tagged arapaima (n = 12) in an upland river‐floodplain (Lake Ayapuá, Amazonas, Brazil). Generalized additive mixed models were used to evaluate environmental, size, and behavioural correlates of breathing intervals.Temperature was the most influential predictor of air‐breathing intervals, followed by body size. The shortest breathing intervals were associated with consecutive ‘aggressive’ breaths while the longest breathing intervals had consecutive ‘calm’ breaths. Type of breath, size, and temperature predictors revealed that breathing intervals ranged from 4 to 46 min and were not significantly different among life stages ( = 15.9 min for sub‐adults and adults (>1 m); = 14.8 min for juveniles (<1 m)).Whereas the current population census method uses fish counts in 20‐min intervals, this study found that 15% of observed breaths, and two thirds of fish, took longer than 20 min to breathe. These findings were obtained in relatively cool‐water environments, so it is recommended that future population census methods consider water temperature (e.g. extend intervals used for counts in cooler waters), which may improve the accuracy of census counts and thus further enhance arapaima conservation efforts.This study demonstrated an effective method in which fundamental biological information is used to inform and improve population census methods for an imperilled fish in a region where traditional stock assessment is ineffective. Similar approaches for adaptive stock assessments could be applied to improve conservation of other air‐breathing fishes (e.g. lungfishes) globally.
Conversion of five proluciferin esters by human cytochrome P450 enzymes
Authors: Sharma Shishir , Sharma Sangeeta Shrestha , Zhang Xue , Bureik Jan‐Philipp , Sorensen Erik J. , Bureik Matthias 
Published: April 2021

AbstractBackgroundProbe substrates are an important tool for activity monitoring of human drug metabolizing enzymes such as cytochromes P450 (CYPs).Brief MethodsIn the present study we have tested human CYPs for metabolization of five proluciferin ester substrates which had previously only been known to be hydroxylated by CYP26A1.Major ResultsIt was found that these substrates were converted by another 21 human CYPs, which belong to the CYP families 1 to 4, 7, and 26. Thus, 66 new pairs of enzyme and substrate were identified. Correlation analysis indicated the presence of three distinct sets of enzymes with high similarity in their activity profiles that encompass a total of 16 individual enzymes.ConclusionsSome of these newly identified correlations may serve as a starting point for further study of those human CYPs whose activities are not yet satisfactorily understood.
Mn3−xFexO4 Hollow Nanostructures for High‐Performance Asymmetric Supercapacitor Applications
Authors: Tan Xueling , Wang Ruonan , Liu Xiaofei , Wang Wei , Cao Lixin , Dong Bohua 
Published: April 2021

AbstractDesign of hollow nanostructure and controllable phase of mixed metal oxides for improving performance in supercapacitor applications is highly desirable. Here we demonstrate the rational design and synthesis of Mn3−xFexO4 hollow nanostructures for supercapacitor applications. Owing to high porosity and the specific surface area that provides more active sites for electrochemical reactions, the electrochemical performance of Mn3−xFexO4 hollow nanostructure substantially enhanced comparing with pristine Mn3O4. Particularly, in 1.0 M KOH electrolyte, Mn0.16Fe2.84O4 with a typical diameter of 20 nm exhibits excellent specific capacitance of 2675, 2320, 1662, 987 F g−1 at current densities of 1, 2, 5, 10 A g−1, respectively, which is significantly superior to those of other transition metal oxides. Besides, an asymmetric supercapacitor is assembled by using Mn0.16Fe2.84O4 and activated carbon as a positive and a negative electrode, respectively. Electrochemical results indicate a high energy density of 42 Wh kg−1 at a power density of 0.75 kW kg−1, which makes this hollow nanostructure a highly promising electrode for achieving high‐performance next‐generation supercapacitors.
From BN‐Naphthalenes to Benzoborole Dianions
Authors: Zhu Dezhao , Guo Lulu , Li Jianfeng , Cui Chunming 
Published: April 2021

AbstractThe synthesis of benzoborole dianions by alkali metal reduction of BN‐naphthalene derivatives via a ring‐contraction strategy has been developed. Reduction of 1‐alkynyl 2,1‐benzazaborine 1 a in Et2O led to the elimination of alkynyllithium with the formation of 1‐amino‐1‐benzoborole trilithium salt 2 a, whereas reduction of 1‐phenyl 2,1‐benzazaborine 1 c in THF yielded 1‐phenyl‐1‐benzoborole dilithium salt 2 c with the elimination of ArNHLi. The trilithium and dilithium salts 2 a and 2 c have been fully characterized. Treatment of trilithium salt 2 a with Et3NHCl led to the selective protonation of the amino lithium to afford the dilithium salt 2 aH, which could be cleanly oxidized to 1‐amino‐1‐benzoborole 3 in an excellent yield. Reaction of 1‐phenyl‐1‐benzoborole dilithium salt 2 c with MeI yielded the lithium borate 4 c, which is luminescent both in solution and in the solid state.
Surfing the Third Wave of Ionic Liquids: A Brief Review on the Role of Surface‐Active Ionic Liquids in Drug Development and Delivery
Authors: Silva Ana Teresa , Teixeira Cátia , Marques Eduardo F. , Prudêncio Cristina , Gomes Paula , Ferraz Ricardo 
Published: April 2021

AbstractThe relevance of ionic liquids (ILs) is now well established in many fields, as their unique properties make them appealing as 1) greener alternatives to organic solvents (first‐generation ILs), 2) tunable task‐specific materials (second‐generation ILs), and 3) multifunctional players in life and pharmaceutical sciences (third‐generation ILs). This third wave of ILs encompasses a wide range of compounds, from bioactive molecules with single or even dual therapeutic action, to potential ingredient molecules for drug formulation and transport systems. In this context, the focus of this review is the emergent role of surface‐active ionic liquids (SAILs) in drug development and delivery.