bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Aligned Bacterial Nanocellulose Films Obtained During Static Biosynthesis in a Reproducible and Straightforward Approach
Authors: Murugarren Nerea , Roig‐Sanchez Soledad , Antón‐Sales Irene , Malandain Nanthilde , Xu Kai , Solano Eduardo , Reparaz Juan Sebastian , Laromaine Anna 
Published: July 2022

AbstractBacterial nanocellulose (BNC) is usually produced as randomly‐organized highly pure cellulose nanofibers films. Its high water‐holding capacity, porosity, mechanical strength, and biocompatibility make it unique. Ordered structures are found in nature and the properties appearing upon aligning polymers fibers inspire everyone to achieve highly aligned BNC (A‐BNC) films. This work takes advantage of natural bacteria biosynthesis in a reproducible and straightforward approach. Bacteria confined and statically incubated biosynthesized BNC nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume confirmed by polarization‐resolved second‐harmonic generation signal and Small Angle X‐ray Scattering. The biosynthesis approach is improved by reusing the bacterial substrates to obtain A‐BNC reproducibly and repeatedly. The suitability of A‐BNC as cell carriers is confirmed by adhering to and growing fibroblasts in the substrate. Finally, the thermal conductivity is evaluated by two independent approaches, i.e., using the well‐known 3ω‐method and a recently developed contactless thermoreflectance approach, confirming a thermal conductivity of 1.63 W mK−1 in the direction of the aligned fibers versus 0.3 W mK−1 perpendicularly. The fivefold increase in thermal conductivity of BNC in the alignment direction forecasts the potential of BNC‐based devices outperforming some other natural polymer and synthetic materials.
The crop insurance demand response to the Wildfire and Hurricane Indemnity Program Plus
Authors: Turner Dylan , Tsiboe Francis 
Published: July 2022

AbstractPrevious literature has suggested that ad hoc disaster aid can crowd out demand for residential flood insurance. However, this phenomenon remains relatively unexplored in the agriculture insurance sector. In this paper, we focus on the most recent ad hoc disaster aid program for US agricultural producers, the Wildfire and Hurricane Indemnity Program Plus (WHIP+). Using county‐level data on WHIP+ payments, we find support for the program crowding out demand for crop insurance. However, we find the issue to be nuanced, noting that the demand response to WHIP+ payments is subject to heterogeneity across several dimensions including commodity, insurance plan, and coverage level.
Flexible drought deciduousness in a neotropical understory herb
Authors: Harenčár Julia G. , Ávila‐Lovera Eleinis , Goldsmith Gregory R. , Chen Grace F. , Kay Kathleen M. 
Published: July 2022

AbstractPremiseAdaptive divergence across environmental gradients is a key driver of speciation. Precipitation seasonality gradients are common in the tropics, yet drought adaptation is nearly unexplored in neotropical understory herbs. Here, we examined two recently diverged neotropical spiral gingers, one adapted to seasonal drought and one reliant on perennial water, to uncover the basis of drought adaptation.MethodsWe combined ecophysiological trait measurements in the field and greenhouse with experimental and observational assessments of real‐time drought response to determine how Costus villosissimus (Costaceae) differs from C. allenii to achieve drought adaptation.ResultsWe found that drought‐adapted C. villosissimus has several characteristics indicating flexible dehydration avoidance via semi‐drought‐deciduousness and a fast economic strategy. Although the two species do not differ in water‐use efficiency, C. villosissimus has a more rapid growth rate, lower leaf mass per area, lower stem density, higher leaf nitrogen, and a strong trend of greater light‐saturated photosynthetic rates. These fast economic strategy traits align with both field‐based observations and experimental dry‐down results. During drought, C. villosissimus displays facultative drought‐deciduousness, losing lower leaves during the dry season and rapidly growing new leaves in the wet season.ConclusionsWe revealed a drought adaptation strategy that has not, to our knowledge, previously been documented in tropical herbs. This divergent drought adaptation evolved recently and is an important component of reproductive isolation between C. villosissimus and C. allenii, indicating that adaptive shifts to survive seasonal drought may be an underappreciated axis of neotropical understory plant diversification.
Antheridiogen controls spatial dynamics of sex expression in naturally occurring gametophytes of the tree fern Cyathea multiflora
Authors: Harrington Aidan D. , Blake‐Mahmud Jennifer , Watkins James E. 
Published: July 2022

AbstractPremiseAntheridiogen systems are a set of pheromonal mechanisms that control sex expression in fern gametophytes. However, antheridiogen has rarely been studied outside of the laboratory, and little is known about its function in natural settings. Combining predictions based on field and laboratory study, we tested whether the sexual structure of gametophytic colonies of a tree fern were attributable to antheridiogen.MethodsGametophytic colonies of the antheridiogen‐producing tree fern Cyathea multiflora were collected at La Selva Biological Station in Costa Rica in January 2019. The sex of each gametophyte was determined, mapped, and spatial statistic approaches were used to examine the distribution of sex in each colony.ResultsIn all gametophytic colonies, males were most common, representing 62–68% of individuals. No hermaphroditic gametophytes were identified in any colony. A quadrat‐based method showed female gametophytes were not clustered in each colony, while male gametophytes were clustered. In two of the colonies, the K(r) test statistic for males was greater than expected compared to random simulations of sex expression, indicating male sex expression was spatially associated with females.ConclusionsThis study provides the first documentation of spatial sex expression in natural settings of gametophytes of an antheridiogen‐producing tree fern species. The profound impact of antheridiogen on gametophytic sex expression in field settings suggests this system is intimately tied to mating system, fitness, and genetic diversity in Cyathea multiflora.
Synthesis of Metal Xanthene‐Bridged Bis‐corroles and their Catalytic Activity in Aerobic Baeyer‐Villiger Oxidation Reaction
Authors: Tang Yan , Li Meng‐Ni , Huang Zhen‐Yu , Liu Hai‐Yang , Xiao Xin‐Yan , Zhang Si‐Quan 
Published: July 2022

AbstractThe metal (M=Co, Cu, Mn, Sn, Fe) xanthene‐bridged bis‐corroles (M2XBC) were synthesized and used for catalyzing aerobic Baeyer‐Villiger (B‐V) oxidation of cyclic ketones to corresponding lactones. It turns out iron (IV) bis‐corrole complex (Fe2XBC) exhibited excellent activity and selectivity towards the B‐V oxidation of various cyclic ketones at very low catalyst loading. The yield of ϵ‐caprolactone could reach 98% with only 0.005 mol% catalyst. The turnover number (TON) of the Fe2XBC catalyst could even be up to 17400 in a gram‐scale oxidation of cyclohexanone, showing the promising for industrial usage. Moreover, the existences of benzoyl radical and benzoylperoxy radical in the reaction were proved by ESI‐HRMS spectra and electron paramagnetic resonance (EPR) spectra. A plausible radical mechanism for the metal bis‐corrole catalyzed aerobic B‐V oxidation of cyclohexanone in the presence benzaldehyde additive was proposed.
Piezochromic Tetracoordinate Boron Complex: Blue‐Shifted and Enhanced Luminescence
Authors: Zou Junjian , Fang Yuanyuan , Shen Yunxia , Xia Yang , Wang Kai , Zhang Cheng , Zhang Yujian 
Published: July 2022

AbstractAchieving blueshifted and enhanced emission from purely organic luminophors remains a major challenge. Herein, we report a tetracoordinate boron complex with polymorphism (Y‐phase and O‐phase)‐dependent luminescence. Impressively, the Y‐phase crystals exhibited rare piezochromic luminescent properties such as pressure‐induced blue‐shifted and enhanced emission. The results of theoretical and experimental tests demonstrated that this phenomenon results from the cooperative effect between the restriction of intramolecular motions and alterable charge transfer (CT) behavior during compression. This work provides an ideal model to investigate the optoelectronic properties of boron complexes. Importantly, manipulating the CT behavior through the electrophilicity of boron atoms may become a new principle for the design of piezochromic materials with blueshifted and enhanced emission.
Direct and Selective Electrocarboxylation of Styrene Oxides with CO2 for Accessing β‐Hydroxy Acids
Authors: Zhang Ke , Ren Bai‐Hao , Liu Xiao‐Fei , Wang Lin‐Lin , Zhang Min , Ren Wei‐Min , Lu Xiao‐Bing , Zhang Wen‐Zhen 
Published: July 2022

AbstractHighly selective and direct electroreductive ring‐opening carboxylation of epoxides with CO2 in an undivided cell is reported. This reaction shows broad substrate scopes within styrene oxides under mild conditions, providing practical and scalable access to important synthetic intermediate β‐hydroxy acids. Mechanistic studies show that CO2 functions not only as a carboxylative reagent in this reaction but also as a promoter to enable efficient and chemoselective transformation of epoxides under additive‐free electrochemical conditions. Cathodically generated α‐radical and α‐carbanion intermediates lead to the regioselective formation of α‐carboxylation products.
Responsive Peptide Nanofibers with Theranostic and Prognostic Capacity
Authors: Sun Bingbing , Guo Xiaoping , Feng Mei , Cao Shoupeng , Yang Haowen , Wu Hanglong , van Stevendaal Marleen H. M. E. , Oerlemans Roy A. J. F. , Liang Jinning , Ouyang Yiqiang , van Hest Jan C. M. 
Published: July 2022

AbstractPhotodynamic therapy (PDT) is a highly promising therapeutic modality for cancer treatment. The development of stimuli‐responsive photosensitizer nanomaterials overcomes certain limitations in clinical PDT. Herein, we report the rational design of a highly sensitive PEGylated photosensitizer‐peptide nanofiber (termed PHHPEG6NF) that selectively aggregates in the acidic tumor and lysosomal microenvironment. These nanofibers exhibit acid‐induced enhanced singlet oxygen generation, cellular uptake, and PDT efficacy in vitro, as well as fast tumor accumulation, long‐term tumor imaging capacity and effective PDT in vivo. Moreover, based on the prolonged presence of the fluorescent signal at the tumor site, we demonstrate that PHHPEG6NFs can also be applied for prognostic monitoring of the efficacy of PDT in vivo, which would potentially guide cancer treatment. Therefore, these multifunctional PHHPEG6NFs allow control over the entire PDT process, from visualization of photosensitizer accumulation, via actual PDT to the assessment of the efficacy of the treatment.
Self‐Healing Fibrous Membranes
Authors: Zhu Miaomiao , Yu Jianyong , Li Zhaoling , Ding Bin 
Published: July 2022

AbstractInspired by the self‐healing function of living organisms, self‐healing materials have been developed in recent decades to very high standards. As a new direction, self‐healing fibrous membranes (SFMs) exhibit both the configuration of a porous structure and self‐healing capability within one material. Different from nonporous self‐healing materials, it is more challenging to introduce self‐healing properties to porous fibrous membrane materials owing to the more complex healing mechanism and microstructure of SFMs. This Minireview focuses on the self‐healing mechanisms, design principles, and preparation strategies of SFMs. The characteristics of SFM self‐healing performance are introduced in detail, and insights and perspectives of SFM preparation and healing mechanisms are put forward. Furthermore, remaining challenges and future developments of SFMs are presented, where the ultimate goal is the design of highly efficient self‐healing and superstable fibrous membranes.
Practical Synthesis of Chiral Allylboronates by Asymmetric 1,1‐Difunctionalization of Terminal Alkenes
Authors: Sun Caocao , Li Yuqiang , Yin Guoyin 
Published: July 2022

AbstractWe report herein a modular catalytic method for the efficient enantioselective synthesis of chiral allylboronates from abundant feedstock chemicals through an asymmetric 1,1‐difunctionalization of alkenes. This protocol is distinguished by its use of an inexpensive chiral catalyst, mild and convenient reaction conditions, wide substrate scope, scalability and practicality. The utility of this method is demonstrated by the rapid synthesis of key intermediates of complex drug molecules. Mechanistic studies reveal that β‐H elimination is a highly regioselective step and the reversible homolysis and convergance to the lower energy pre‐reductive elimination intermediate is the enantio‐determining step.
Competitive Adsorption: Reducing the Poisoning Effect of Adsorbed Hydroxyl on Ru Single‐Atom Site with SnO2for Efficient Hydrogen Evolution
Authors: Zhang Jiachen , Chen Guangbo , Liu Qicheng , Fan Chuang , Sun Dongmei , Tang Yawen , Sun Hanjun , Feng Xinliang 
Published: July 2022

AbstractRuthenium (Ru) has been theoretically considered a viable alkaline hydrogen evolution reaction electrocatalyst due to its fast water dissociation kinetics. However, its strong affinity to the adsorbed hydroxyl (OHad) blocks the active sites, resulting in unsatisfactory performance during the practical HER process. Here, we first reported a competitive adsorption strategy for the construction of SnO2nanoparticles doped with Ru single‐atoms supported on carbon (Ru SAs‐SnO2/C) via atomic galvanic replacement. SnO2was introduced to regulate the strong interaction between Ru and OHadby the competitive adsorption of OHadbetween Ru and SnO2, which alleviated the poisoning of Ru sites. As a consequence, the Ru SAs‐SnO2/C exhibited a low overpotential at 10 mA cm−2(10 mV) and a low Tafel slope of 25 mV dec−1. This approach provides a new avenue to modulate the adsorption strength of active sites and intermediates, which paves the way for the development of highly active electrocatalysts.
Dysprosium–balsalazide complex trapped between the functionalized halloysite and g‐C3N4: A novel heterogeneous catalyst for the synthesis of annulated chromenes in water
Authors: Rahimzadeh Golnaz , Tajbakhsh Mahmood , Daraie Mansoureh , Mohammadi Masoud 
Published: July 2022

In this work, a complex of dysprosium and balsalazide was trapped between the functionalized g‐C3N4 and halloysite via a simple approach. The resulting [Hal‐BS/g‐C3N4‐Dy]‐heterogenized complex was characterized using FT‐IR, SEM, EDX, elemental mapping, XRD, ICP‐OES, and TGA. The catalytic activity of [Hal‐BS/g‐C3N4‐Dy] was examined in the synthesis of an array of biologically active pyran derivatives, that is, the 2‐amino‐5,10‐dioxo‐4‐aryl‐5,10‐dihydro‐4H‐benzo[g]chromene‐3‐carbonitriles. This reaction was achieved in water as a green solvent under reflux condition. The desired products were obtained in excellent yields (up to 98%). In addition, the reusability of this novel catalyst was investigated for 8 cycles without losing catalytic activity and under the optimal reaction conditions. The ICP‐OES test demonstrated that there was no leaching of metal during the catalytic reaction, indicating the heterogeneous manner of the catalyst.
Functional core/shell PMMA/P(MMA‐co‐PDSECAE)‐SH particles with thiol groups in the shell and their adsorption of heavy metal ions
Authors: Han Lu , Li Lingxiao , Gao Rongsheng , Liu Xueyan , Kan Chengyou 
Published: July 2022

AbstractThe relationships between morphology and properties are important for functional polymer particles. In this work, stable core/shell PMMA/P(MMA‐co‐PDSECAE) (C/S) latexes with uniform particle size are first prepared through semi‐continuous soap‐free seeded emulsion polymerization of methyl methacrylate (MMA) and 2‐(((2‐[pyridin‐2‐yldisulfanyl]ethoxy)carbonyl)amino) ethyl acrylate (PDSECAE), and thiol‐functionalized core/shell PMMA/P(MMA‐co‐PDSECAE)‐SH (C/S‐SH) submicron particles (SPs) are then obtained by reduction of disulfide bonds with dithiothreitol (DTT). Adsorption behaviors of heavy metal ions on the SPs are investigated. Results show that, the C/S‐SH SPs, with more thiol groups distributed closer to the surface, have nearly twice the Pb2+ adsorption capacity of the homogeneous SPs prepared via batch emulsion polymerization. The C/S‐SH SPs show strong selective adsorption capacities toward Hg2+ and Pb2+, and maximum adsorption capacities reach 0.477 and 0.303 mmol g−1, respectively. Due to their high selectivity, adsorption capacity, specific surface area and simple preparation process, these core/shell SPs have promising applications in water treatment.
Preparation of polyimide aerogels by freeze‐extraction and chemical imidization for 3D printing
Authors: Guo Yuxiong , Qin Shiyu , Yao Xinle , Liu Sen , Ji Zhongying , Ma Zhengfeng , Wang Xiaolong 
Published: July 2022

AbstractPolyimide (PI) aerogels with excellent mechanical and thermal stability, low density, and flexibility have attracted extensive attention in recent years. However, the existing preparation method usually requires chemical pre‐crosslinking followed by supercritical drying or freeze drying, and then thermal imidization, which has the weakness of a complicated preparation method and high cost. In this study, PI aerogels were prepared by a simple method that involved freeze extraction and chemical imidization, which exhibited low density (0.14 g cm−3), high porosity (85.61%), excellent thermal stability (T5% and Tg were 418.12 and 230.60°C, respectively), shape fidelity, and compressibility. Furthermore, this method regulated the pore size, such as the macro/microstructure, and then used the PI aerogel ink to build complex architectures by 3D printing. As a proof of concept, pyramids, multilayer grids, ring‐hole disks, Chinese knots and cuboids were printed, and all of them exhibited the shape fidelity property after freeze‐extraction and chemical imidization. Therefore, we believe this novel preparation method enables significant promotion of the application potential of PI aerogels and 3D printing.
The ScMo‐350 site, Haumi, Moʻorea (Society Islands): Preliminary analysis of coastal occupation spanning the colonization phase to classic phase
Authors: Kahn Jennifer G. 
Published: July 2022

ABSTRACTIn the Society Islands, multi‐phase coastal sites with successive occupations spanning several centuries have been difficult to find and have been poorly studied, resulting in a vague understanding of this archipelago's founding cultural complex and its adaptations to specific island environments through time. Discovery and excavation of ScMo‐350, a well‐stratified coastal site in Haumi, Moʻorea, Society Islands, provides robust sample sizes for understanding the timing and function of early Māʻohi coastal settlements and their constellation of use through time. My discussion of the site focuses on four topics: methodological issues for identifying early colonization sites in Central Eastern Polynesia; site stratigraphy and dating; the timing of island colonization on Moʻorea and its comparison to the Faʻahia site on Huahine; and preliminary analysis of ScMo‐350 sub‐surface features and artifacts to understand site function and its change through time. Bayesian analysis of short‐lived samples from ScMo‐350's earliest deposits and those from the Faʻahia site are described in an effort to refine our understanding of the Society Islands’ Colonization Phase.
Querkrafttragverhalten stahlfaserverstärkter UHFB‐Biegeträger mit Kompaktquerschnitt
Authors: Metje Kevin , Leutbecher Torsten 
Published: July 2022

AbstractBei Biegeträgern aus stahlfaserverstärktem ultrahochfesten Beton (UHFB) unterscheidet sich das Querkrafttragverhalten je nach Querschnittsform. Balken mit gegliedertem Querschnitt zeigen typischerweise ein Schub‐Zug‐Versagen des dünnen Stegs. Hingegen tritt bei Balken mit Kompaktquerschnitt Biegeschubversagen auf. Somit sind Bemessungsansätze, die den Querkraftwiderstand eines Bauteils ohne Querkraftbewehrung, die Wirkung einer Vorspannung sowie Traganteile aus Bügeln und Fasern überlagern, nicht zwangsläufig auf beide Querschnittsformen gleichermaßen anwendbar. Ziel der vorliegenden Studie war es, das Querkrafttragverhalten von UHFB‐Balken mit Kompaktquerschnitt und insbesondere die Einflüsse des Fasergehalts und des Vorspanngrads auf die Entwicklung des kritischen Schubrisses und die Querkrafttragfähigkeit zu untersuchen. Hierzu wurden 22 Querkraftversuche durchgeführt. Rissbildung und ‐ausbreitung wurden mittels digitaler Bildkorrelation überwacht. In den Versuchen konnte ein deutlicher Einfluss des Fasergehalts und des Vorspanngrads auf die Schubrisskraft festgestellt werden. Die Probekörper ohne Vorspannung zeigten überwiegend ein typisches Biegeschubversagen, während bei den vorgespannten Probekörpern die Betondruckzone unter kombinierter Beanspruchung aus Biegeschub und Biegedruck versagte. Anhand der Ergebnisse wurde ein additiver Bemessungsansatz überprüft. Er liefert für alle Versuche eine konservative Abschätzung der Schubrisskraft.
Enhancing thermal stability and lytic activity of phage lysin PlyAB1 from Acinetobacter baumannii
Authors: Yuan Yingbo , Li Qingbin , Zhang Shuhang , Gu Jinhong , Huang Guangtao , Qi Qingsheng , Lu Xuemei 
Published: July 2022

AbstractWith the increasingly serious drug resistance of Acinetobacter baumannii, there is an increasingly urgent need for new antibacterial drugs. Phage lysin PlyAB1 has a bactericidal effect on drug‐resistant A. baumannii, which has the potential to replace antibiotics to fight infection caused by A. baumannii. However, its application is limited by its thermal stability and lytic activity. To solve these problems, molecular dynamics (MD) simulations combined with Hotspot wizard 3.0 were used to identify key residue sites affecting thermal stability, and evolutionary analysis combined with multiple sequence alignment was used to identify key residue sites affecting lytic activity. Four single‐point variants with significantly increased thermal stability and four single‐point variants with significantly lytic activity were obtained, respectively. Furthermore, by superimposing mutations, we obtained three double‐point variants, G100Q/K69R, G100R/K69R, and G100K/K69R, with significantly improved thermal stability and improved lytic activity. At 45°C, the lytic activity and half‐life of the optimal variant G100Q/K69R were 1.51‐ and 24‐fold higher than those of the wild PlyAB1, respectively. These results deepen our understanding of the structure and function of phage lysin and contribute to the application of phage lysin in antibiotic substitution.