bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protozoan Diversity and Biogeography
Authors: Pearson Leanne A , Neilan Brett A 
Published: May 2021

Abstract

Protozoa is an informal name used to describe a polyphyletic group of single‐celled eukaryotic organisms (protists) that feed mostly by heterotrophy. Over 26 000 morphospecies of protists have been named, spanning all modern eukaryotic supergroups. They are incredibly diverse in terms of physiology and lifestyle, which has enabled them to colonise a wide range of moist environments, including marine, freshwater and extreme habitats. Many species have evolved specialised anatomical structures for feeding, motility and exchange of genetic material. They can be free‐living, parasitic or symbiotic, or can transition between these states. Some are also capable of forming dormant cysts or spores, which enable them to resist environmental stress. Species were traditionally defined based on morphological features and modes of nutrition, which do not always correlate with phylogenetic similarity; thus, it is difficult to ascertain their true biodiversity and biogeography. However, some appear to be abundant and widespread in nature, while others are rare and limited to very specific environmental niches.

Key Concepts

‘Protozoa’ is not a formal phylogenetic taxon but is loosely used to describe diverse unicellular eukaryotic organisms (protists) with a mostly heterotrophic lifestyle.

Protists are found in virtually all moist environments on Earth, including fresh and marine water, soil, extreme environments and the fluids of plants and animals.

Protists may be free‐living, parasitic or symbiotic, or may transition between these lifestyles.

In order to persist under stressful conditions, some species may form dormant cysts or spores. These structures also enable protists to survive passive transport from one location to the next. Protists may have a variety of specialised anatomical structures for feeding, locomotion and the exchange of genetic material, including extrusomes, pseudopodia and cilia.

The taxonomy of protists was traditionally based on morphological features and nutritional mode but, has since been revised based on biochemical and genetic similarities. Many of the previously described morphospecies are actually clusters of several phylogenetically distinct entities.

As a group, protists are incredibly abundant and geographically widespread. Common species may be present in densities of tens of thousands of cells per litre of water (or gram of soil), for example. However, some species are relatively rare.

Despite their capacity for global distribution, most species display some degree of endemism.
Protein‐Coding Segments: Evolution of Exon–Intron Gene Structure
Authors: Igor Rogozin 
Published: May 2021

Abstract

Many eukaryotic genes are disrupted by noncoding regions of DNA of variable sizes called introns, giving the genes an exon–intron structure. Origin and evolution of introns is an important, long‐standing problem. The availability of multiple, complete genome sequences allows one to address many fundamental evolutionary questions. Analysis of orthologous genes from completely sequenced eukaryotic genomes revealed numerous shared intron positions in orthologous genes between animals, fungi, plants and protists. The data on intron positions were used as the starting point for evolutionary reconstruction with various phylogenetic methods. These methods reconstructed intron‐rich ancestors but in many cases inferred lineage‐specific high levels of intron loss and gain. These results indicate that numerous introns were present already at the earliest stages of evolution of eukaryotes and are compatible with the hypothesis that the original, catastrophic intron invasion accompanied the emergence of the eukaryotic cells.

Key Concepts

The exon–intron gene structure is highly dynamic.

Orthologous genes from distant eukaryotic species share up to 25–30% intron positions.

Intron gains and losses might occur during limited time spans.

The last eukaryotic common ancestor was intron rich.

In the course of evolution the splice signal shifts from exons to introns.

The scenario of the origin and evolution of introns that is best compatible with the results of comparative genomics goes as follows: self‐splicing introns since the earliest stages of life's evolution followed by numerous spliceosomal introns invading genes of the emerging eukaryotes and subsequent lineage‐specific loss and gain of spliceosomal introns.
Reproductive Strategies
Authors: Fox Gordon A 
Published: May 2021

Abstract

The ‘reproductive strategies’ of organisms – the timing and intensity of reproduction, mortality and growth in their life cycles – can have large effects on their Darwinian fitness. A ‘strategy’ in this context should be understood as a ‘syndrome’ that affects Darwinian fitness, rather than as implying conscious intent. That these strategies do evolve can be seen by considering the immense variation among species in quantities like the numbers of offspring produced, length of lifespan, age when reproduction begins, and number of reproductive bouts. Experiments have demonstrated that these traits do respond to selection. The theory of the evolution of reproductive strategies is based on the demography of populations. Making this theory useful in particular studies can depend on two tasks, both of which can be daunting. Some realism in estimating and modelling the capture and allocation of resources is necessary, as are estimates of how fitness consequences vary over time.

Key Concepts

Organisms vary considerably in their reproductive strategies, from reproducing once in a long lifespan to reproducing frequently in much shorter life spans.

The traits affecting reproductive strategies can have large effects on Darwinian fitness, and as a result, they evolve.

Availability of resources strongly constrains the evolution of reproductive strategies, causing their evolution along trade‐offs between competing demographic functions.

Contemporary theory of the evolution of reproductive strategies focuses on demographic consequences of changes in age‐ or state‐specific survival and fertility.

Changing survival or fertility involves allocating resources to traits affecting them.

A key challenge is making measurement and modelling of resources biologically reasonable.

Since the environment varies over time, fitness in the long term depends on the geometric (rather than the usual arithmetic) mean of the rate of growth.

Senescence can be a consequence of natural selection, but it does not always do so.
A Manganese Phosphate Cathode for Long‐Life Aqueous Energy Storage
Authors: Yang Duo , Song Yu , Zhang Ming‐Yue , Qin Zengming , Dong Ran , Li Cuicui , Liu Xiao‐Xia 
Published: May 2021

AbstractMn‐based materials for aqueous energy storage are reaching the capacity ceiling due to the limited Mn4+/Mn3+ redox. The disproportionation of Mn3+ often occurs, forming soluble Mn2+ and thus leading to severer capacity decays. Here, an amorphous manganese phosphate material [AMP, Na1.8Mn4O1.4(PO4)3] is fabricated using an electrochemical method for the first time. Benefitting from the open framework and the insoluble nature of Mn2+ in AMP, the Mn3+/Mn2+ and Mn4+/Mn3+ redox couples can participate in the charge storage processes. The AMP electrode shows a high capacity of 253.4 mAh g−1 (912.4 F g−1 or 912.4 C g−1) at the current density 1 A g−1 and good rate capability. Experimental results indicate AMP experiences a mixed charge storage mechanism (i.e., cation intercalation and conversion reactions) in Na2SO4 electrolyte. Besides, electrolyte engineering can effectively prevent the decomposition of AMP during cycling test, achieving capacity retention of 97% in 5000 cycles. Importantly, AMP can accommodate different cations (e.g., Mg2+, Ca2+, etc.), exhibiting great potential for aqueous energy storage.
Safeguarding Osteointegration in Diabetic Patients: A Potent “Chain Armor” Coating for Scavenging ROS and Macrophage Reprogramming in a Microenvironment‐Responsive Manner
Authors: He Qingqing , Yuan Shuai , Tang Han , Wang Si , Mu Zhixiang , Li Dize , Wang Shan , Jing Xuan , Hu Shanshan , Ji Ping , Chen Tao 
Published: May 2021

AbstractRisk of implant failure increases profoundly in patients with pre‐existing conditions (e.g., diabetes). Current therapies adopt a one‐sided focus on the direct antibacterial properties of biomaterials and osteogenesis stimulation. However, in this study it is demonstrated that a “chain armor” structure (Ce‐TA) that mainly targets the regulation of the local pathological microenvironment, provides a novel solution to scavenge reactive oxygen species (ROS) by simulating superoxide dismutase and catalase and significantly improving osteointegration under diabetic conditions. Ce‐TA based on a metal phenolic network biological functional interface is successfully constructed. Ce‐TA, an ultrathin armor structure, is biocompatible and facile. Through in vitro assays it is demonstrated that Ce‐TA reshapes the diabetic microenvironment into a regenerative one in a microenvironment‐responsive manner, where Ce‐TA regulates hypoxia‐inducible factor 1α (HIF‐1α) activity by reducing the level of mitochondrial ROS, and effectively alleviates mitochondrial dysfunction and reprogrammes macrophages to a pro‐healing state. Furthermore, it is confirmed that Ce‐TA shows excellent therapeutic effects on the reducing postoperative infection and enhances osteointegration of intra‐osseous implants in diabetic rat models. The proposed strategy opens up a promising opportunity for repurposing metals with intrinsic enzyme‐like activity for the goal of enhancing the osteointegration of devices with orthopedic and dental applications among diabetic patients.
Polyhedral Oligomeric Silsesquioxanes Based Ultralow‐k Materials: The Effect of Cage Size
Authors: Zhou Dai‐Lin , Li Jiang‐Hui , Guo Qing‐Yun , Lin Xiong , Zhang Qin , Chen Feng , Han Di , Fu Qiang 
Published: May 2021

AbstractPolyhedral oligomeric silsesquioxanes (POSS) are of considerable interest as building blocks for preparing low‐k materials. To date T8 POSS has been extensively investigated while the potential of larger POSS cages remain an unexplored area. Herein, the first known contribution to map the role of POSS cage size on the dielectric and other comprehensive properties of hybrid materials with identical chemical compositions is described. First, three vinyl POSS (T8, T10, and T12) species are isolated from a commercial POSS mixture. Then, they are converted to benzocyclobutene functionalized and thermo‐crosslinked hybrid materials. It is found that the cage size can strongly affect their k values, more importantly, showing a linear decrease while increasing the cage volumes (k = 2.24, 2.02, and 1.83 for c‐T8B8, c‐T10B10, and c‐T12B12, respectively). This finding highlights a profound influence of POSS cage changes on dielectric properties and could be used to predict ultralow‐k (1.5–1.1) materials by extrapolating to larger T14, T16, and T18 POSS cages. Meanwhile, varying the cage size has no obvious effect on the materials’ other properties, and all of them exhibit good comprehensive properties. Moreover, such low‐k values can persist at high temperature and high humidity conditions, which affords some promising (ultra)low‐k dielectrics for modern integrated circuit development.
Photo‐Triggered Shape Reconfiguration in Stretchable Reduced Graphene Oxide‐Patterned Azobenzene‐Functionalized Liquid Crystalline Polymer Networks
Authors: Cho Woongbi , Jeon Jisoo , Eom Wonsik , Lee Jae Gyeong , Kim Dong‐Gyun , Kim Yong Seok , Han Tae Hee , Wie Jeong Jae 
Published: May 2021

AbstractIn recent years, the “Kirigami” have been exploited to engineer stretchable electronics that exhibit enhanced deformability without sacrificing their mechanical and electrical properties. However, kirigami‐inspired engineering is often limited to passive mechanical stretching for 3D shape morphing. To counter this problem, in this study, azobenzene‐functionalized liquid crystalline polymer networks (azo‐LCNs) are monolithically integrated with patterned reduced graphene oxide (rGO), called azo‐LCN/rGO, to achieve on‐demand shape reconfiguration in response to external stimuli (UV, NIR, solar rays, and portable light); in addition, the azo‐LCN/rGO exhibit highly enhanced mechanical and electrical properties. The cross‐sectional area and thickness of rGO patterns are controlled using a masking technique and evaporative self‐assembly. By the spatial patterning of rGO, insulating azo‐LCNs are converted into electrically conducting structures (381.9 S cm−1). The elastic modulus of <2 µm thick azo‐LCN can be tailored in the range of 1.3–6.4 GPa by integration with rGO layers of thickness less than 2 µm. Upon UV irradiation, azo‐LCN/rGO exhibit both for/backward in‐plane bending as well as out‐of‐plane chiral twisting, thus overcoming the typical trade‐off relationship between elastic modulus and deformability. Finally, an on‐demand contactless shape reconfiguration in azo‐LCN/rGO by UV irradiation in conjunction with passive mechanical strain is demonstrated.
Metallic Plasmonic Array Structures: Principles, Fabrications, Properties, and Applications
Authors: Yang Kang , Yao Xu , Liu Bowen , Ren Bin 
Published: May 2021

AbstractThe vast development of nanofabrication has spurred recent progress for the manipulation of light down to a region much smaller than the wavelength. Metallic plasmonic array structures are demonstrated to be the most powerful platform to realize controllable light–matter interactions and have found wide applications due to their rich and tunable optical performance through the morphology and parameter engineering. Here, various light‐management mechanisms that may exist on metallic plasmonic array structures are described. Then, the typical techniques for fabrication of metallic plasmonic arrays are summarized. Next, some recent applications of plasmonic arrays are reviewed, including plasmonic sensing, surface‐enhanced spectroscopies, plasmonic nanolasing, and perfect light absorption. Lastly, the existing challenges and perspectives for metallic plasmonic arrays are discussed. The aim is to provide guidance for future development of metallic plasmonic array structures.
Repurposing Poly(3‐hexylthiophene) as a Conductivity‐Reducing Additive for Polyethylene‐Based High‐Voltage Insulation
Authors: Pourrahimi Amir Masoud , Kumara Sarath , Palmieri Fabrizio , Yu Liyang , Lund Anja , Hammarström Thomas , Hagstrand Per‐Ola , Scheblykin Ivan G. , Fabiani Davide , Xu Xiangdong , Müller Christian 
Published: May 2021

AbstractPoly(3‐hexylthiophene) (P3HT) is found to be a highly effective conductivity‐reducing additive for low‐density polyethylene (LDPE), which introduces a new application area to the field of conjugated polymers. Additives that reduce the direct‐current (DC) electrical conductivity of an insulation material at high electric fields have gained a lot of research interest because they may facilitate the design of more efficient high‐voltage direct‐current power cables. An ultralow concentration of regio‐regular P3HT of 0.0005 wt% is found to reduce the DC conductivity of LDPE threefold, which translates into the highest efficiency reported for any conductivity‐reducing additive to date. The here‐established approach, i.e., the use of a conjugated polymer as a mere additive, may boost demand in absolute terms beyond the quantities needed for thin‐film electronics, which would turn organic semiconductors from a niche product into commodity chemicals.
Organic Solar Cells with 18% Efficiency Enabled by an Alloy Acceptor: A Two‐in‐One Strategy
Authors: Liu Feng , Zhou Liang , Liu Wenrui , Zhou Zichun , Yue Qihui , Zheng Wenyu , Sun Ri , Liu Wuyue , Xu Shengjie , Fan Haijun , Feng Liheng , Yi Yuanping , Zhang Wenkai , Zhu Xiaozhang 
Published: May 2021

AbstractThe trade‐off between the open‐circuit voltage (Voc) and short‐circuit current density (Jsc) has become the core of current organic photovoltaic research, and realizing the minimum energy offsets that can guarantee effective charge generation is strongly desired for high‐performance systems. Herein, a high‐performance ternary solar cell with a power conversion efficiency of over 18% using a large‐bandgap polymer donor, PM6, and a small‐bandgap alloy acceptor containing two structurally similar nonfullerene acceptors (Y6 and AQx‐3) is reported. This system can take full advantage of solar irradiation and forms a favorable morphology. By varying the ratio of the two acceptors, delicate regulation of the energy levels of the alloy acceptor is achieved, thereby affecting the charge dynamics in the devices. The optimal ternary device exhibits more efficient hole transfer and exciton separation than the PM6:AQx‐3‐based system and reduced energy loss compared with the PM6:Y6‐based system, contributing to better performance. Such a “two‐in‐one” alloy strategy, which synergizes two highly compatible acceptors, provides a promising path for boosting the photovoltaic performance of devices.
Engineering of Active Sites in Metal–Organic Frameworks for Biodiesel Production
Authors: Cirujano Francisco G. , Dhakshinamoorthy Amarajothi 
Published: May 2021

AbstractThe production of biodiesel using solid catalysts is a sustainable methodology to renewable fuels from the valorization of biomass derived oils and fats. Here, the use of tailorable multifunctional metal–organic frameworks (MOFs) as heterogeneous catalysts for esterification/transesterification reactions is reviewed, which allows the synthesis of biodiesel molecules under broader and safer conditions. The influence of engineering of active sites at either the nodes or porous cavities in MOFs as reusable Lewis/Brönsted acid catalysts to produce higher yields of biodiesel during several reaction cycles is described. The examples described here indicate the promising activity and stability of these novel materials in the sustainable production of biofuels.
Fluorinated Chitosan Mediated Synthesis of Copper Selenide Nanoparticles with Enhanced Penetration for Second Near‐Infrared Photothermal Therapy of Bladder Cancer
Authors: Zhang Shaohua , Li Guangzhi , Deng Dashi , Dai Yizhi , Liu Zhuang , Wu Song 
Published: May 2021

AbstractThe emergence of near‐infrared‐II (NIR‐II) light activated photomedicines has extended the penetration depth for noninvasive theranostics, especially for photothermal nanomedicines. Intravesical instillation therapy of bladder cancer (BCa) is restricted greatly due to the short residence time and the low penetration ability of therapeutic agents in clinic. Therefore, improving the mucoadhesiveness and penetration of therapeutic agents are crucial factors in treatment of BCa. The development of NIR‐II light triggered photothermal transduction agents for enhanced penetration and photothermal ablation of BCa post‐intravesical instillation has not yet been investigated. Herein, Cu2‐xSe biocompatible particles are prepared through a fluorinated chitosan (FCS)‐mediated one‐pot aqueous approach, which possesses enhanced penetrating ability and high photothermal conversion capability for effective NIR‐II photothermal therapy (PTT). Owing to the outstanding transmucosal ability of FCS, FCS capped Cu2‐xSe nanoparticles exhibit much better transmucosal and penetration performance than their non‐fluorinated counterparts to significantly improve the therapeutic efficacy of NIR‐II PTT to ablate orthotopic bladder tumors. This study presents a promising phototherapy agent based on Cu2‐xSe modified with FCS for efficient NIR‐II PTT for BCa treatment post‐intravesical instillation.
Advanced Switchable Molecules and Materials for Oil Recovery and Oily Waste Cleanup
Authors: Lu Yi , Zhu Yeling , Yang Fan , Xu Zhenghe , Liu Qingxia 
Published: May 2021

AbstractAdvanced switchable molecules and materials have shown great potential in numerous applications. These novel materials can express different states of physicochemical properties as controlled by a designated stimulus, such that the processing condition can always be maintained in an optimized manner for improved efficiency and sustainability throughout the whole process. Herein, the recent advances in switchable molecules/materials in oil recovery and oily waste cleanup are reviewed. Oil recovery and oily waste cleanup are of critical importance to the industry and environment. Switchable materials can be designed with various types of switchable properties, including i) switchable interfacial activity, ii) switchable viscosity, iii) switchable solvent, and iv) switchable wettability. The materials can then be deployed into the most suitable applications according to the process requirements. An in‐depth discussion about the fundamental basis of the design considerations is provided for each type of switchable material, followed by details about their performances and challenges in the applications. Finally, an outlook for the development of next‐generation switchable molecules/materials is discussed.
Methyltransferase‐Like Protein 14 Attenuates Mitochondrial Antiviral Signaling Protein Expression to Negatively Regulate Antiviral Immunity via N6‐methyladenosine Modification
Authors: Qin Fei , Cai Baoshan , Zhao Jian , Zhang Lei , Zheng Yi , Liu Bingyu , Gao Chengjiang 
Published: May 2021

AbstractMitochondrial antiviral signaling (MAVS) protein is the core signaling adaptor in the RNA signaling pathway. Thus, appropriate regulation of MAVS expression is essential for antiviral immunity against RNA virus infection. However, the regulation of MAVS expression at the mRNA level especially at the post transcriptional level is not well‐defined. Here, it is reported that the MAVS mRNA undergoes N6‐methyladenosine (m6A) modification through methyltransferase‐like protein 14 (METTL14), which leads to a fast turnover of MAVS mRNA. Knockdown or deficiency of METTL14 increases MAVS mRNA stability, and downstream phosphorylation of TBK1/IRF3 and interferon‐β production in response to RNA viruses. Compared to wild‐type mice, heterozygotes Mettl14+/− mice better tolerate RNA virus infection. The authors' findings unveil a novel mechanism to regulate the stability of MAVS transcripts post‐transcriptionally through m6A modification.
Nano‐Scale Complexions Facilitate Li Dendrite‐Free Operation in LATP Solid‐State Electrolyte
Authors: Stegmaier Sina , Schierholz Roland , Povstugar Ivan , Barthel Juri , Rittmeyer Simon P. , Yu Shicheng , Wengert Simon , Rostami Samare , Kungl Hans , Reuter Karsten , Eichel Rüdiger‐A. , Scheurer Christoph 
Published: May 2021

AbstractDendrite formation and growth remains a major obstacle toward high‐performance all solid‐state batteries using Li metal anodes. The ceramic Li(1+x)Al(x)Ti(2−x)(PO4)3 (LATP) solid‐state electrolyte shows a higher than expected stability against electrochemical decomposition despite a bulk electronic conductivity that exceeds a recently postulated threshold for dendrite‐free operation. Here, transmission electron microscopy, atom probe tomography, and first‐principles based simulations are combined to establish atomistic structural models of glass‐amorphous LATP grain boundaries. These models reveal a nanometer‐thin complexion layer that encapsulates the crystalline grains. The distinct composition of this complexion constitutes a sizable electronic impedance. Rather than fulfilling macroscopic bulk measures of ionic and electronic conduction, LATP might thus gain the capability to suppress dendrite nucleation by sufficient local separation of charge carriers at the nanoscale.