bluuebunny/crossref_metadata_2025 huggingface dataset:
Struktur subjektiver Theorien über Musikalität und Validierung eines Messinstruments
Authors: Eisinger Miriam
Published: August 2021

Musiker*innen werden geboren, nicht gemacht. Diese Überzeugung findet sich häufig in der allgemeinen Bevölkerung, bei vielen Musiker*innen und auch Musiklehrpersonen. Im Rahmen dieser Überzeugung wird Musikalität als angeboren und unveränderbar angesehen. Solch eine stabile Subjektive Theorie über Musikalität steht im Gegensatz zu einer dynamischen Subjektiven Theorie über Musikalität, bei der musikalische Fähigkeiten als veränderbar und erlernbar betrachtet werden. Eine dynamische Subjektive Theorie über Musikalität ist jedoch ein entscheidender Faktor dafür, dass Personen ihr musikalisches Potential entfalten können. Um die Subjektiven Theorien über Musikalität empirisch erfassen zu können, war das Ziel der vorliegenden Studie die Struktur der Subjektiven Theorien in der Domäne Musik mithilfe eines englisch- und eines deutschsprachigen Messinstruments zu überprüfen. Dafür wurde ein für den Musikbereich adaptiertes Selbstauskunftsinventar von englischen (n = 595, 71,6 % weiblich, M = 13,49, SD = 1,74) und deutschen (n = 385, 53,2 % weiblich, M = 10,51, SD = 0,71) Schüler*innen ausgefüllt. Die Ergebnisse der Reliabilitätsüberprüfungen und der konfirmatorischen Faktorenanalyse sprechen für ein multidimensionales, hierarchisches Konstrukt, welches zwei Faktoren zweiter Ordnung enthält (Entity und Incremental), und weiter differenziert zwischen der Ursache und der Veränderbarkeit von Musikalität mit vier Faktoren erster Ordnung (Learning vs. Gift und Improvement vs. Stable). Durch das Messinstrument können bei zukünftigen (Langzeit-) Untersuchungen individuelle Unterschiede in der Entwicklung musikalischer Subjektiver Theorien von Schüler*innen aufgedeckt und der Einfluss der Subjektiven Theorien über Musikalität auf die allgemeine musikalische Entwicklung untersucht werden.
Performance Preparation, Anxiety, and the Teacher. Experiences of Adolescent Pianists
Authors: Ryan Charlene , Boucher Hélène , Ryan Gina
Published: August 2021

The purpose of this study was to examine the experiences of adolescent pianists in their private lessons and solo performances in regard to concert preparation and music performance anxiety (mpa). A particular focus was placed on the student-teacher relationship and the potential role of teachers in students’ preparation, experience, and anxiety in performance situations. 62 piano students completed questionnaires pertaining to their private lessons, teacher, and performance experiences, as well as two inventories—one pertaining to self-esteem and the other on music performance anxiety. Results indicate that self-esteem and practice are significant predictors of mpa, with self-esteem having the most notable effect. Almost half of the participants reported feeling nervous in their lessons at least some of the time. Most students noted that their teachers encourage them to perform; however, only half reported that their teachers address performance preparation issues. Less than half were reported to discuss memorization strategies or management of mpa with students, or to hold practice-performance classes. Implications for music educators and future research directions are discussed.
Induire une écoute audiotechnique au moyen de la stéréophonie monumentale. Musique pour les premiers spectacles son et lumière1
Authors: Goldman Jonathan
Published: August 2021

Écouter le son spatialisé au moyen d’appareils électroniques constitue une des nouvelles expériences arrivées au lendemain de la Seconde Guerre mondiale. En ce qui concerne l’histoire de cette nouvelle forme d’écoute audiotechnique en France, l’une des manifestations du son stéréophonique qui a eu le plus d’impact auprès du public fut sans doute les spectacles son et lumière, dont le premier de l’histoire eut lieu en 1952 au château de Chambord, avec une musique signée Maurice Jarre. La partie sonore de ce spectacle était le fruit d’un dispositif stéréophonique inédit. Les spectacles son et lumière ont initié de nombreux auditeurs à une nouvelle forme d’écoute directionnelle, une habileté exploitée ensuite par une génération de compositeurs d’avant-garde. Cet article se penche sur la dimension musicale de ces spectacles afin de mesurer leur impact sur l’entraînement de l’oreille du public général à la musique qui conquit l’espace au moyen de la stéréophonie.
Dynamic study of a new five-dimensional conservative hyperchaotic system with wide parameter range
Authors: Zhang Ze-Feng , Huang Li-Lian , Xiang Jian-Hong , Liu Shuai ,   College of Information and Communication Engineering, Harbin Engineering University, Harbin 150001, China,   MIIT Key Laboratory of Advanced Marine Communication and Information Technology, Harbin Engineering University, Harbin 150001, China
Published: August 2021

Conservative systems have no attractors. Therefore, compared with common dissipative systems, conservative systems have good ergodicity, strong pseudo-randomness and high security performance, thereby making them more suitable for applications in chaotic secure communication and other fields. Owing to these features, a new five-dimensional conservative hyperchaotic system with a wide parameter range is designed. Firstly, the Hamiltonian energy and Casimir energy are analyzed, showing that the new system satisfies the Hamiltonian energy conservation and can generate chaos. Next, the dynamic analysis is carried out, including conservativeness proof, equilibrium point analysis, Lyapunov exponential spectrum, and bifurcation diagrams analysis, thereby proving that the new system has the characteristics of conservative system and can always maintain a hyperchaotic state in a wide parameter range. At the same time, the phase diagram and Poincaré section diagram of the new system in a wide parameter range are compared. The results show that the randomness and ergodicity of the system are enhanced with the increase of parameters. Then, the NIST test shows that the chaotic random sequences generated by the new system in a wide parameter range have strong pseudo-randomness. Finally, the circuit simulation and hardware circuit experiment of the conservative hyperchaotic system are carried out, which proves that the new system has good ergodicity and realizability.
Integrated simulation of plasma current profile in HL-2A high confinement mode(H mode)
Authors: Zhang Hong-Ming , Wu Jing , Li Jia-Xian , Yao Lie-Ming , Xu Jiang-Cheng , Wu Yan-Zhan , Liu Qi-Yan , Guo Peng-Cheng ,   School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China,   Fusion Research Institute, Southwestern Institute of Physics, Chengdu 610225, China
Published: August 2021

The plasma current (Ip), magnetic field (B), and safety factor distribution (q profile) of the HL-2A tokamak device are crucial to monitoring the steady-state operational scenarios (in high confinement mode, H mode). Based on real experimental data and integrated modeling simulation method (OMFIT), the plasma parameters’ profiles such as magnetic field configuration and current density profiles in H mode were reconstructed. By building up an integrated simulation platform for dynamic equilibrium configuration, and combining the rapid workflow processing method and experimental data with integrated simulation models, the ion and electron temperature, density, and current density profiles were obtained. The integration simulation platform was established to reconstruct the internal magnetic surface configuration, the plasma boundary parameter distribution, the ion/electron temperature, current density, and the q profile. The Ohmic current, bootstrap current, and radio-frequency current profiles with its fractions were calculated. The width of the pedestal region was about 7.52 cm according to our simulation results. It was found that the pressure gradient changes its direction at radial coordinate ρ(r/a) = 0.1 and reaches its maximum value near ρ = 0.7, which may be the internal transport barrier (ITB) configuration caused by negative shear. The profile reconstruction and real-time monitoring of the physical parameters are conducive to evaluating the quality of H mode discharge experiment and can assist in the steady-state operation of advanced operating modes such as HL-2M high normalized beta (βn) discharge.
The development of active binocular vision under normal and alternate rearing conditions
Authors: Klimmasch Lukas , Schneider Johann , Lelais Alexander , Fronius Maria , Shi Bertram Emil , Triesch Jochen
Published: August 2021

The development of binocular vision is an active learning process comprising the development of disparity tuned neurons in visual cortex and the establishment of precise vergence control of the eyes. We present a computational model for the learning and self-calibration of active binocular vision based on the Active Efficient Coding framework, an extension of classic efficient coding ideas to active perception. Under normal rearing conditions with naturalistic input, the model develops disparity tuned neurons and precise vergence control, allowing it to correctly interpret random dot stereograms. Under altered rearing conditions modeled after neurophysiological experiments, the model qualitatively reproduces key experimental findings on changes in binocularity and disparity tuning. Furthermore, the model makes testable predictions regarding how altered rearing conditions impede the learning of precise vergence control. Finally, the model predicts a surprising new effect that impaired vergence control affects the statistics of orientation tuning in visual cortical neurons.
An in vitro stem cell model of human epiblast and yolk sac interaction
Authors: Mackinlay Kirsty ML , Weatherbee Bailey AT , Souza Rosa Viviane , Handford Charlotte E , Hudson George , Coorens Tim , Pereira Lygia V , Behjati Sam , Vallier Ludovic , Shahbazi Marta N , Zernicka-Goetz Magdalena
Published: August 2021

Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.
KLF10 integrates circadian timing and sugar signaling to coordinate hepatic metabolism
Authors: Ruberto Anthony A , Gréchez-Cassiau Aline , Guérin Sophie , Martin Luc , Revel Johana S , Mehiri Mohamed , Subramaniam Malayannan , Delaunay Franck , Teboul Michèle
Published: August 2021

The mammalian circadian timing system and metabolism are highly interconnected, and disruption of this coupling is associated with negative health outcomes. Krüppel-like factors (KLFs) are transcription factors that govern metabolic homeostasis in various organs. Many KLFs show a circadian expression in the liver. Here, we show that the loss of the clock-controlled KLF10 in hepatocytes results in extensive reprogramming of the mouse liver circadian transcriptome, which in turn alters the temporal coordination of pathways associated with energy metabolism. We also show that glucose and fructose induce Klf10, which helps mitigate glucose intolerance and hepatic steatosis in mice challenged with a sugar beverage. Functional genomics further reveal that KLF10 target genes are primarily involved in central carbon metabolism. Together, these findings show that in the liver KLF10 integrates circadian timing and sugar metabolism-related signaling, and serves as a transcriptional brake that protects against the deleterious effects of increased sugar consumption.
Insulin-producing β-cells regenerate ectopically from a mesodermal origin under the perturbation of hemato-endothelial specification
Authors: Liu Ka-Cheuk , Villasenor Alethia , Bertuzzi Maria , Schmitner Nicole , Radros Niki , Rautio Linn , Mattonet Kenny , Matsuoka Ryota L , Reischauer Sven , Stainier Didier YR , Andersson Olov
Published: August 2021

To investigate the role of the vasculature in pancreatic β-cell regeneration, we crossed a zebrafish β-cell ablation model into the avascular npas4l mutant (i.e. cloche). Surprisingly, β-cell regeneration increased markedly in npas4l mutants owing to the ectopic differentiation of β-cells in the mesenchyme, a phenotype not previously reported in any models. The ectopic β-cells expressed endocrine markers of pancreatic β-cells, and also responded to glucose with increased calcium influx. Through lineage tracing, we determined that the vast majority of these ectopic β-cells has a mesodermal origin. Notably, ectopic β-cells were found in npas4l mutants as well as following knockdown of the endothelial/myeloid determinant Etsrp. Together, these data indicate that under the perturbation of endothelial/myeloid specification, mesodermal cells possess a remarkable plasticity enabling them to form β-cells, which are normally endodermal in origin. Understanding the restriction of this differentiation plasticity will help exploit an alternative source for β-cell regeneration.
How will mosquitoes adapt to climate warming?
Authors: Couper Lisa I , Farner Johannah E , Caldwell Jamie M , Childs Marissa L , Harris Mallory J , Kirk Devin G , Nova Nicole , Shocket Marta , Skinner Eloise B , Uricchio Lawrence H , Exposito-Alonso Moises , Mordecai Erin A
Published: August 2021

The potential for adaptive evolution to enable species persistence under a changing climate is one of the most important questions for understanding impacts of future climate change. Climate adaptation may be particularly likely for short-lived ectotherms, including many pest, pathogen, and vector species. For these taxa, estimating climate adaptive potential is critical for accurate predictive modeling and public health preparedness. Here, we demonstrate how a simple theoretical framework used in conservation biology—evolutionary rescue models—can be used to investigate the potential for climate adaptation in these taxa, using mosquito thermal adaptation as a focal case. Synthesizing current evidence, we find that short mosquito generation times, high population growth rates, and strong temperature-imposed selection favor thermal adaptation. However, knowledge gaps about the extent of phenotypic and genotypic variation in thermal tolerance within mosquito populations, the environmental sensitivity of selection, and the role of phenotypic plasticity constrain our ability to make more precise estimates. We describe how common garden and selection experiments can be used to fill these data gaps. Lastly, we investigate the consequences of mosquito climate adaptation on disease transmission using Aedes aegypti-transmitted dengue virus in Northern Brazil as a case study. The approach outlined here can be applied to any disease vector or pest species and type of environmental change.
Receptor repertoires of murine follicular T helper cells reveal a high clonal overlap in separate lymph nodes in autoimmunity
Authors: Niebuhr Markus , Belde Julia , Fähnrich Anke , Serge Arnauld , Irla Magali , Ellebrecht Christoph T , Hammers Christoph M , Bieber Katja , Westermann Jürgen , Kalies Kathrin
Published: August 2021

Follicular T helper cells (Tfh) are a specialized subset of CD4 effector T cells that are crucial for germinal center (GC) reactions and for selecting B cells to undergo affinity maturation. Despite this central role for humoral immunity, only few data exist about their clonal distribution when multiple lymphoid organs are exposed to the same antigen (Ag) as it is the case in autoimmunity. Here, we used an autoantibody-mediated disease model of the skin and injected one auto-Ag into the two footpads of the same mouse and analyzed the T cell receptor (TCR)β sequences of Tfh located in GCs of both contralateral draining lymph nodes. We found that over 90% of the dominant GC-Tfh clonotypes were shared in both lymph nodes but only transiently. The initially dominant Tfh clonotypes especially declined after establishment of chronic disease while GC reaction and autoimmune disease continued. Our data demonstrates a dynamic behavior of Tfh clonotypes under autoimmune conditions and emphasizes the importance of the time point for distinguishing auto-Ag-specific Tfh clonotypes from potential bystander activated ones.
Non-linear genetic diversity and notable population differentiation caused by low gene flow of bermudagrass [Cynodon dactylon(L.) Pers.] along longitude gradients
Authors: Zhang Jing-Xue , Wang Miaoli , Fan Jibiao , Guo Zhi-Peng , Guan Yongzhuo , Qu Gen , Zhang Chuan-Jie , Guo Yu-Xia , Yan Xuebing
Published: August 2021

Background

Environmental variation related to ecological habitat is the main driver of plant adaptive divergence. Longitude plays an important role in the formation of plant population structure, indicating that environmental differentiation can significantly shape population structure.

Methods

Genetic diversity and population genetic structure were estimated using 105 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. A total of 249C. dactylon(L.) Pers. (common bermudagrass) individuals were sampled from 13 geographic sites along the longitude (105°57′34″–119°27′06″E).

Results

There was no obvious linear trend of intra-population genetic diversity along longitude and the intra-population genetic diversity was not related to climate in this study. Low gene flow (Nm = 0.7701) meant a rich genetic differentiation among populations ofC. dactylonalong longitude gradients. Significantly positive Mantel correlation (r = 0.438,P= 0.001) was found between genetic distance and geographical interval while no significant partial Mantel correlation after controlling the effect of mean annual precipitation, which indicated geographic distance correlated with mean annual precipitation affect genetic distance. The genetic diversity ofC. dactylonwith higher ploidy level was higher than that with lower ploidy level and groups of individuals with higher ploidy level were separated further away by genetic distance from the lower ploidy levels. Understanding the different genetic bases of local adaptation comparatively between latitude and longitude is one of the core findings in the adaptive evolution of plants.
Assessment of Cage Culture Practices in Chandil Reservoir, Jharkhand
Authors: Kumari Shweta , Sharma Arpita , Choudhary Arup Kumar , Ananthan P. S. , Ojha S. N. , Sharma Rama , Landge Asha
Published: August 2021

The present study was carried out in Chandil reservoir which is situated in Saraikela-Kharsawan district, Jharkhand and has 933 cages installed for fish culture. The objective of the study was to assess cage culture practices in this reservoir. The assessment was done using the NFDB guidelines of cage culture in inland open water bodies of India using 15 parameters. Interviews with officials of Department of Fisheries and fishers was done to enquire if the guidelines were followed using a 3 point scale. This was corroborated by observation and field visits, so as to adopt the triangulation method. It was found that 66.67% of the guidelines were being followed fully. However, 33.33% of guidelines like water quality, cage maintenance, fish health monitoring, use of safety measures and environment precaution and assessment, guidelines were partly followed due to certain reasons. Accordingly suggestions have been provided. It was concluded that the cage culture practices followed in Chandil reservoir is good. Improvements can be done on those parameters where guidelines are being partly followed.
The Role of Certain Congenital Infections in Aplastic Anemia and Prognostic Value of Fetal Hemoglobin as a Follow-Up Marker
Authors: Sheta Enas Ahmed , El-Hawary Eslam El-Sayed , Elbendary Amal Saeid , Shebl Shebl Said
Published: August 2021

Background: TORCH infection has a role in aplastic anemia (AA). Fetal hemoglobin may be high in certain acquired hematological conditions such as aplastic anemia. We conducted this study to evaluate the correlation between certain congenital infections and severity of aplastic anemia and to study fetal Hb as a follow up marker during treatment of aplastic anemia. The aim of study was to correlation between certain congenital infection and severity of aplastic anemia and to study of hemoglobin F (HbF) as a follow up marker during treatment of aplastic anemia.

Methods: Our prospective study was conducted on 20 children aged up to 18 years diagnosed with aplastic anemia following either bone marrow aspiration or biopsy that proves bone marrow hypocellularity with absence infiltrative BM disease or inherited BM disease recruited from Pediatric Hematology-Oncology Unit of Tanta University Hospital. Patients were classified according to level of HbF in to high HbF group and normal HbF group.

Results: TORCH infections were detected in certain numbers of patients . HbF decreased in high HbF group after treatment. There was significant increase in CBC parameters in high HbF group than normal HbF group after treatment. There was insignificant decrease in mortality in high HbF group than normal HbF group. Mild to moderate cases were significantly higher with TORCH IgM +ve cases

Conclusions: Acquired AA is associated with TORCH infection. In treated cases of AA, improvement of hematological parameters is associated with high HbF and from these results, it can be used as a prognostic marker to monitor the successful response of these cases to the used line of treatment.
Changes Associated with Treatment of Plasmodium berghei Infected Mice with Momordica charantia, Xylopia aethiopica and Entandrophragma angolense Leaf Extract
Authors: Kareem Fatai A. , Owolabi Opeyemi J. , Alabi Mutiu A. , Ogunsuyi Omotola B. , AbdulKadir Sofiyat F. , Obatoye Ayodeji O.
Published: August 2021

Aim: Leaves of plants have been useful in the treatment of various diseases and infections. The study aims at determining the nephrotoxicity, hepatotoxicity, and hematological effect of Momordica charantia, Xylopia aethiopica, and Entandrophragma angolense on the Plasmodium berghei infected mice.

Study Design: The plants’ leaves were air-dried and extracted. Forty-two Swiss male mice, 18 to 25 g, were grouped into six of seven mice each. Group I was uninfected but were administered with normal saline for four days, Group II to VI were all infected with P. berghei and administered with normal saline, 300 mg/b.w. of M. charantia leaf extract, 300 mg/b.w. of E. angolense leaf extract, 300 mg/b.w. of X. aethiopica leaf extract and 40 mg/b.w. of chloroquine injection for four days, respectively.

Results: The treatment groups showed a lower level of toxicity when compared with chloroquine treatment. X. aethiopica has the greatest positive impact on the PCV level of the experimental animals of its treated group compared with other groups.

Conclusion: Our findings confirmed the antimalarial potential of X. aethiopica and thus can be used to treat malaria without anemia as a side effect.
A Case Report on Late-onset Friedrich's Ataxia and Response on Parkinsonism Treatment
Authors: Gupta Uma Datta , Chowdhury Tutul
Published: August 2021

Friedrich's ataxia is a progressive neurodegenerative disease that affects the posterior cord of the spinal tract. We present a case of an 83-year-old male with resting tremor and rigidity that had gradually worsened over the past few years. The patient has been diagnosed with Friedrich's ataxia. Unlike typical Friedrich ataxia, this patient does not have a shortened life expectancy. There is a small percentage of atypical patients demonstrate late-onset of disease, isolated spastic paraparesis without ataxia, and retained or exacerbated deep tendon reflex. Although there is no association between Parkinson's disease and Friedrich's ataxia; in our case, treatment of tremor and rigidity improves the patient's quality of life.
Iron, Nitrogen Co‐Doped Carbon Spheres as Low Cost, Scalable Electrocatalysts for the Oxygen Reduction Reaction
Authors: Feng Jingyu , Cai Rongsheng , Magliocca Emanuele , Luo Hui , Higgins Luke , Romario Giulio L. Fumagalli , Liang Xiaoqiang , Pedersen Angus , Xu Zhen , Guo Zhenyu , Periasamy Arun , Brett Dan , Miller Thomas S. , Haigh Sarah J. , Mishra Bhoopesh , Titirici Maria‐Magdalena
Published: August 2021

Atomically dispersed transition metal‐nitrogen‐carbon catalysts are emerging as low‐cost electrocatalysts for the oxygen reduction reaction in fuel cells. However, a cost‐effective and scalable synthesis strategy for these catalysts is still required, as well as a greater understanding of their mechanisms. Herein, iron, nitrogen co‐doped carbon spheres (Fe@NCS) have been prepared via hydrothermal carbonization and high‐temperature post carbonization. It is determined that FeN4 is the main form of iron existing in the obtained Fe@NCS. Two different precursors containing Fe2+ and Fe3+ are compared. Both chemical and structural differences have been observed in catalysts starting from Fe2+ and Fe3+ precursors. Fe2+@NCS‐A (starting with Fe2+ precursor) shows better catalytic activity for the oxygen reduction reaction. This catalyst is studied in an anion exchange membrane fuel cell. The high open‐circuit voltage demonstrates the potential approach for developing high‐performance, low‐cost fuel cell catalysts.
Scalable, Template Driven Formation of Highly Crystalline Lead‐Tin Halide Perovskite Films
Authors: Xi Jun , Duim Herman , Pitaro Matteo , Gahlot Kushagra , Dong Jingjin , Portale Giuseppe , Loi Maria Antonietta
Published: August 2021

Low bandgap lead‐tin halide perovskites are predicted to be candidates to maximize the performance of single junction and tandem solar cells based on metal halide perovskites. In spite of the tremendous progress in lab‐scale device efficiency, devices fabricated with scalable techniques fail to reach the same efficiencies, which hinder their potential industrialization. Herein, a method is proposed that involves a template of a 2D perovskite deposited with a scalable technique (blade coating), which is then converted in situ to form a highly crystalline 3D lead‐tin perovskite. These templated grown films are alloyed with stoichiometric ratio and are highly oriented with the (l00) planes aligning parallel to the substrate. The low surface/volume ratio of the obtained single‐crystal‐like films contributes to their enhanced stability in different environments. Finally, the converted films are demonstrated as active layer for solar cells, opening up the opportunity to develop this scalable technique for the growth of highly crystalline hybrid halide perovskites for photovoltaic devices.
Multifunctional Superelastic Cellulose Nanofibrils Aerogel by Dual Ice‐Templating Assembly
Authors: Qin Hengfei , Zhang Yifan , Jiang Jungang , Wang Lili , Song Mingyao , Bi Ran , Zhu Penghui , Jiang Feng
Published: August 2021

A superelastic aerogel with fast shape recovery performance from large compressive strain is highly desired for numerous applications such as thermal insulation in clothing, high‐sensitive sensors, and oil contaminant removal. Fabrication of superelastic cellulose nanofibrils (CNF) aerogels is challenging as the CNF can assemble into non‐elastic sheet‐like cell walls. Here, a dual ice‐templating assembly (DITA) strategy is proposed that can control the assembly of CNF into sub‐micrometer fibers by extremely low temperature freezing (–196 °C), which can further assemble into an elastic aerogel with interconnected sub‐micron fibers by freezer freezing (−20 °C) and freeze drying. The CNF aerogel from the DITA process demonstrates isotropic superelastic behavior that can recover from over 80% compressive strain along both longitudinal and cross‐sectional directions, even in an extremely cold liquid nitrogen environment. The elastic CNF aerogel can be easily modified by chemical vapor deposition of organosilane, demonstrating superhydrophobicity (164° water contact angle), high liquid absorption (489 g g−1 of chloroform absorption capacity), self‐cleaning, thermal insulating (0.023 W (mK)−1), and infrared shielding properties. This new DITA strategy provides a facile design of superelastic aerogels from bio‐based nanomaterials, and the derived high performance multifunctional elastic aerogel is expected to be useful for a wide‐range of applications.
Rational Cathode Design for High‐Power Sodium‐Metal Chloride Batteries
Authors: Graeber Gustav , Landmann Daniel , Svaluto‐Ferro Enea , Vagliani Fabrizio , Basso Diego , Turconi Alberto , Heinz Meike V. F. , Battaglia Corsin
Published: August 2021

The transition from fossil fuels to renewable energy sources requires economic, high‐performance electrochemical energy storage. High‐temperature sodium‐metal chloride batteries combine long cycle and calendar life, with high specific energy, no self‐discharge, and minimum maintenance requirements, while employing abundant raw materials. However, large‐scale deployment in mobility and stationary storage applications is currently hindered by high production cost of the complex, commercial tubular cells and limited rate capability. The present study introduces sodium‐metal chloride cells with a simple, planar architecture that provide high specific power while maintaining the inherent high specific energy. Rational cathode design, considering critical transport processes and the effect of cathode composition on the cell resistance, enables the development of high‐performance cells with average discharge power of 1022 W kg−1 and discharge energy per cycle of 258 Wh kg−1 on cathode composite level, shown over 140 cycles at an areal capacity of 50 mAh cm−2. This corresponds to a 3.2C discharge over 80% of full charge. Compared to the best performing planar sodium‐metal chloride cells with similar cycling stability and mass loading in the literature, the presented performance represents an increase in specific power by more than a factor of four, while also raising the specific energy by 74%.
Improving the Stability of Non‐Noble‐Metal M–N–C Catalysts for Proton‐Exchange‐Membrane Fuel Cells through M–N Bond Length and Coordination Regulation
Authors: Miao Zhengpei , Wang Xiaoming , Zhao Zhonglong , Zuo Wenbin , Chen Shaoqing , Li Zhiqiang , He Yanghua , Liang Jiashun , Ma Feng , Wang Hsing‐Lin , Lu Gang , Huang Yunhui , Wu Gang , Li Qing
Published: August 2021

An effective and universal strategy is developed to enhance the stability of the non‐noble‐metal M–Nx/C catalyst in proton exchange membrane fuel cells (PEMFCs) by improving the bonding strength between metal ions and chelating polymers, i.e., poly(acrylic acid) (PAA) homopolymer and poly(acrylic acid–maleic acid) (P(AA‐MA)) copolymer with different AA/MA ratios. Mössbauer spectroscopy and X‐ray absorption spectroscopy (XAS) reveal that the optimal P(AA‐MA)–Fe–N catalyst with a higher Fe3+–polymer binding constant possesses longer FeN bonds and exclusive Fe–N4/C moiety compared to PAA–Fe–N, which consists of ≈15% low‐coordinated Fe–N2/N3 structures. The optimized P(AA‐MA)–Fe–N catalyst exhibits outstanding ORR activity and stability in both half‐cell and PEMFC cathodes, with the retention rate of current density approaching 100% for the first 37 h at 0.55 V in an H2–air fuel cell. Density functional theory (DFT) calculations suggest that the Fe–N4/C site could optimize the difference between the adsorption energy of the Fe atoms on the support (Ead) and the bulk cohesive energy (Ecoh) relative to Fe–N2/N3 moieties, thereby strongly stabilizing Fe centers against demetalation.
Fused‐Silica 3D Chiral Metamaterials via Helium‐Assisted Microcasting Supporting Topologically Protected Twist Edge Resonances with High Mechanical Quality Factors
Authors: Köpfler Julian , Frenzel Tobias , Schmalian Jörg , Wegener Martin
Published: August 2021

It is predicted theoretically that a 1D diatomic chain of 3D chiral cells can support a topological bandgap that allows for translating a small time‐harmonic axial movement at one end of the chain into a resonantly enhanced large rotation of an edge state at the other end. This edge state is topologically protected such that an arbitrary mass of a mirror at the other end does not shift the eigenfrequency out of the bandgap. Herein, this complex 3D laser‐beam‐scanner microstructure is realized in fused‐silica form. A novel microcasting approach is introduced that starts from a hollow polymer cast made by standard 3D laser nanoprinting. The cast is evacuated and filled with helium, such that a highly viscous commercial glass slurry is sucked in. After UV curing and thermal debinding of the polymer, the fused‐silica glass is sintered at 1225 °C under vacuum. Detailed optical measurements reveal a mechanical quality factor of the twist‐edge resonance of 2850 at around 278 kHz resonance frequency under ambient conditions. The microcasting approach can likely be translated to many other glasses, to metals and ceramics, and to complex architectures that are not or not yet amenable to direct 3D laser printing.
Highly Efficient and Robust Broadband Nano‐VO2(M) Saturable Absorber for Nonlinear Optics and Ultrafast Photonics
Authors: Wang Fang , Chen Haobin , Lan Dongfang , Zhang Fan , Sun Yue , Zhang Xuenan , Li Shuguang , Cheng Tonglei
Published: August 2021

The metal‐to‐insulator transition behavior and the fast and reversible phase transition behavior in vanadium dioxide (VO2) have attracted widespread attention to study various potential applications. However, few studies have been focused on its nonlinear properties and applications in the pulsed laser field. Here, the authors report the design and synthesis of monoclinic nano‐VO2(M) saturable absorber with broadband absorption which spans the entire near‐infrared region, and high optical nonlinearity which is much higher than those of carbon nanomaterials, gold nanocrystals, and Cu1.8S nanocrystals, as measured in the same condition. The nano‐VO2(M) optical modulators are integrated into the fiber laser cavities, and demonstrate wideband Q‐switching operations at 1, 1.56, and 2 µm and mode‐locking operation at 2 µm, with a pulse duration of 765 fs. This work first reveals the outstanding nonlinear optical properties of nano‐VO2(M) and lays a foundation for its development in advanced nonlinear optical and photonic devices.
Encapsulating Cobalt Nanoparticles in Interconnected N‐Doped Hollow Carbon Nanofibers with Enriched CoNC Moiety for Enhanced Oxygen Electrocatalysis in Zn‐Air Batteries
Authors: Lu Qi , Wu Han , Zheng Xuerong , Chen Yanan , Rogach Andrey L. , Han Xiaopeng , Deng Yida , Hu Wenbin
Published: August 2021

Rational design of bifunctional efficient electrocatalysts for both oxygen reduction (ORR) and oxygen evolution reactions (OER) is desirable—while highly challenging—for development of rechargeable metal–air batteries. Herein, an efficient bifunctional electrocatalyst is designed and fabricated by encapsulating Co nanoparticles in interconnected N‐doped hollow porous carbon nanofibers (designated as Co@N‐C/PCNF) using an ultrafast high‐temperature shock technology. Benefiting from the synergistic effect and intrinsic activity of the CoNC moiety, as well as porous structure of carbon nanofibers, the Co@N‐C/PCNF composite shows high bifunctional electrocatalytic activities for both OER (289 mV at 10 mA cm−2) and ORR (half‐wave potential of 0.85 V). The CoNC moiety in the composite can modulate the local environmental and electrical structure of the catalysts, thus optimizing the adsorption/desorption kinetics and decreasing the reaction barriers for promoting the reversible oxygen electrocatalysis. Co@N‐C/PCNF‐based aqueous Zn–air batteries (AZAB) provide high power density of 292 mW cm−2, and the assembled flexible ZAB can power wearable devices.
Nonlinear Behavior of Dendritic Polymer Networks for Reservoir Computing
Authors: Petrauskas Lautaro , Cucchi Matteo , Grüner Christopher , Ellinger Frank , Leo Karl , Matthus Christian , Kleemann Hans
Published: August 2021

Organic electrochemical devices are an emerging class of devices with synaptic properties that might allow for the implementation of next‐generation neuromorphic circuits for power‐efficient computing. Here, a brain‐inspired neural network approach, namely reservoir computing, which relies on a nonlinear transformation of a low‐dimensional input signal onto a high‐dimensional output space for information processing is utilized. The implementation of reservoir computing using dendritic networks of polymeric fibers is demonstrated and the nonlinear response of the polymer networks are analyzed and the sources of nonlinearity are identified. Furthermore, by adding a delayed feedback loop to the reservoir, it is proven that such a network can undergo a bifurcation into a chaotic state, proving sufficient complexity of the system for advanced classification tasks with time‐dependent data. Ultimately, a classification task is carried out and the accuracy is compared of the classification of different degrees of complexity of the system, showing an increase in accuracy from 60% for the base network to 80% when the delayed feedback loop is incorporated.
Design and Construction of Deformable Heaters: Materials, Structure, and Applications
Authors: Hu Zhiqiang , Zhou Jian , Fu Qiang
Published: August 2021

Conventional heaters have evolved from traditional rigid heaters to flexible heaters, stretchable heaters, and deformable heaters for the development of soft electronics. Film‐based or filament‐based heaters can be designed and engineered to fulfill the deformable, adaptable and stretchable applications. Compared with conventional heaters, deformable heaters can maintain stable electrothermal property even with large deformation. Based on this, deformable heaters have shown great potential to be used in the field of Internet of Things and work together with other electronic devices. This review summarizes the structure design strategies to achieve deformable heaters. Parameters, such as electrical conductivity, stretchability, thermal capacity, and thermal diffusivity, play essential roles in the effective design and development of heating devices. New methodologies and fabrication processes are developed to obtain deformable heaters that are expected to be highly conductive, adaptable, and conformable, as well as can be readily integrated with wearable fabrics. This review introduces the latest advances from conventional heaters to deformable heaters, emphasizing key recent developments on methodologies and fabrication processes and strategies geared toward applications in electronic skin, healthcare, deicing, sensors, and actuators. The challenges in this area are critically evaluated, and the perspectives for developing future deformable heaters are presented.
Current State‐of‐the‐Art in the Interface/Surface Modification of Thermoelectric Materials
Authors: He Shiyang , Lehmann Sebastian , Bahrami Amin , Nielsch Kornelius
Published: August 2021

Thermoelectric (TE) materials are prominent candidates for energy converting applications due to their excellent performance and reliability. Extensive efforts for improving their efficiency in single‐/multi‐phase composites comprising nano/micro‐scale second phases are being made. The artificial decoration of second phases into the thermoelectric matrix in multi‐phase composites, which is distinguished from the second‐phase precipitation occurring during the thermally equilibrated synthesis of TE materials, can effectively enhance their performance. Theoretically, the interfacial manipulation of phase boundaries can be extended to a wide range of materials. High interface densities decrease thermal conductivity when nano/micro‐scale grain boundaries are obtained and certain electronic structure modifications may increase the power factor of TE materials. Based on the distribution of second phases on the interface boundaries, the strategies can be divided into discontinuous and continuous interfacial modifications. The discontinuous interfacial modifications section in this review discusses five parts chosen according to their dispersion forms, including metals, oxides, semiconductors, carbonic compounds, and MXenes. Alternatively, gas‐ and solution‐phase process techniques are adopted for realizing continuous surface changes, like the core–shell structure. This review offers a detailed analysis of the current state‐of‐the‐art in the field, while identifying possibilities and obstacles for improving the performance of TE materials.
Biokatalytische C3‐Indol‐Methylierung – ein nützliches Werkzeug für die naturstoffinspirierte stereoselektive Synthese von Pyrroloindolen
Authors: Schneider Pascal , Henßen Birgit , Paschold Beatrix , Chapple Benjamin P. , Schatton Marcel , Seebeck Florian P. , Classen Thomas , Pietruszka Jörg
Published: August 2021

Die enantioselektive Synthese bioaktiver Verbindungen, die ein Pyrroloindolgerüst tragen, ist oft aufwändig. Im Gegensatz dazu sind mehrere S‐Adenosylmethionin (SAM)‐abhängige Methyltransferasen bekannt, die stereo‐ und regioselektive Methylierungen an der C3‐Position verschiedener Indole durchführen und damit eine direkte Bildung des gewünschten Pyrroloindolgerüsts ermöglichen. Hier wird die SAM‐abhängige Methyltransferase PsmD aus Streptomyces griseofuscus, ein Schlüsselenzym in der Biosynthese von Physostigmin, im Detail charakterisiert. Die biochemischen Eigenschaften von PsmD und ihr Substratspektrum werden aufgezeigt. Die enzymatische Methylierung im präparativen Maßstab, einschließlich der SAM‐Regeneration, wurde für drei ausgewählte Substrate nach einer Design‐of‐Experiment‐Optimierung erreicht.
Stable Anion‐Derived Solid Electrolyte Interphase in Lithium Metal Batteries
Authors: Li Tao , Zhang Xue‐Qiang , Yao Nan , Yao Yu‐Xing , Hou Li‐Peng , Chen Xiang , Zhou Ming‐Yue , Huang Jia‐Qi , Zhang Qiang
Published: August 2021

High‐energy‐density lithium (Li) metal batteries are severely hindered by the dendritic Li deposition dictated by non‐uniform solid electrolyte interphase (SEI). Despite its unique advantages in improving the uniformity of Li deposition, the current anion‐derived SEI is unsatisfactory under practical conditions. Herein regulating the electrolyte structure of anions by anion receptors was proposed to construct stable anion‐derived SEI. Tris(pentafluorophenyl)borane (TPFPB) anion acceptors with electron‐deficient boron atoms interact with bis(fluorosulfonyl)imide anions (FSI−) and decrease the reduction stability of FSI−. Furthermore, the type of aggregate cluster of FSI− in electrolyte changes, FSI− interacting with more Li ions in the presence of TPFPB. Therefore, the decomposition of FSI− to form Li2S is promoted, improving the stability of anion‐derived SEI. In working Li | LiNi0.5Co0.2Mn0.3O2 batteries under practical conditions, the anion‐derived SEI with TPFPB undergoes 194 cycles compared with 98 cycles of routine anion‐derived SEI. This work inspires a fresh ground to construct stable anion‐derived SEI by manipulating the electrolyte structure of anions.
Sustainable Pd(OAc)2/Hydroquinone Cocatalyst System for Cis‐Selective Dibenzoyloxylation of 1,3‐Cyclohexadiene
Authors: Stamoulis Alexios G. , Geng Peng , Schmidt Michael A. , Eastgate Martin D. , Borovika Alina , Fraunhoffer Kenneth J. , Stahl Shannon S.
Published: August 2021

The 1,4‐diacyloxylation of 1,3‐cyclohexadiene (CHD) affords valuable stereochemically defined scaffolds for natural product and pharmaceutical synthesis. Existing cis‐selective diacyloxylation protocols require superstoichiometric quantities of benzoquinone (BQ) or MnO2, which limit process sustainability and large‐scale application. In this report, reaction development and mechanistic studies are described that overcome these limitations by pairing catalytic BQ with tert‐butyl hydroperoxide as the stoichiometric oxidant. Catalytic quantities of bromide enable a switch from trans to cis diastereoselectivity. A catalyst with a 1:2 Pd:Br ratio supports high cis selectivity while retaining good rate and product yield. Further studies enable replacement of BQ with hydroquinone (HQ) as a source of cocatalyst, avoiding the handling of volatile and toxic BQ in large‐scale applications.
Enantioselective Total Synthesis of (+)‐Garsubellin A
Authors: Jang Dongseok , Choi Minchul , Chen Jinglong , Lee Chulbom
Published: August 2021

Garsubellin A is a meroterpene capable of enhancing the enzyme choline acetyltransferase whose decreased level is believed to play a central role in the symptoms of Alzheimer's disease. Due to the potentially useful biological activity together with the novel bridged and fused cyclic molecular architecture, garsubellin A has garnered substantial synthetic interest, but its absolute stereostructure has been undetermined. We report here the first enantioselective total synthesis of (+)‐garsubellin A. Our synthesis relies on stereoselective fashioning of a cyclohexanone framework and double conjugate addition of 1,2‐ethanedithiol that promotes aldol cyclization to build the bicyclic [3.3.1] skeleton. The twelve‐step, protecting group‐free synthetic route has enabled the syntheses of both the natural (−)‐garsubellin A and its unnatural (+)‐antipode for biological evaluations.
Visible‐Light‐Driven Catalytic Deracemization of Secondary Alcohols
Authors: Zhang Zhikun , Hu Xile
Published: August 2021

Deracemization of racemic chiral compounds is an attractive approach in asymmetric synthesis, but its development has been hindered by energetic and kinetic challenges. Here we describe a catalytic deracemization method for secondary benzylic alcohols which are important synthetic intermediates and end products for many industries. Driven by visible light only, this method is based on sequential photochemical dehydrogenation followed by enantioselective thermal hydrogenation. The combination of a heterogeneous dehydrogenation photocatalyst and a chiral molecular hydrogenation catalyst is essential to ensure two distinct pathways for the forward and reverse reactions. These reactions convert a large number of racemic aryl alkyl alcohols into their enantiomerically enriched forms in good yields and enantioselectivities.