bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Progress in Active Mechanical Metamaterials and Construction Principles
Authors: Qi Jixiang , Chen Zihao , Jiang Peng , Hu Wenxia , Wang Yonghuan , Zhao Zeang , Cao Xiaofei , Zhang Shushan , Tao Ran , Li Ying , Fang Daining
Published: October 2021

Active mechanical metamaterials (AMMs) (or smart mechanical metamaterials) that combine the configurations of mechanical metamaterials and the active control of stimuli‐responsive materials have been widely investigated in recent decades. The elaborate artificial microstructures of mechanical metamaterials and the stimulus response characteristics of smart materials both contribute to AMMs, making them achieve excellent properties beyond the conventional metamaterials. The micro and macro structures of the AMMs are designed based on structural construction principles such as, phase transition, strain mismatch, and mechanical instability. Considering the controllability and efficiency of the stimuli‐responsive materials, physical fields such as, the temperature, chemicals, light, electric current, magnetic field, and pressure have been adopted as the external stimuli in practice. In this paper, the frontier works and the latest progress in AMMs from the aspects of the mechanics and materials are reviewed. The functions and engineering applications of the AMMs are also discussed. Finally, existing issues and future perspectives in this field are briefly described. This review is expected to provide the basis and inspiration for the follow‐up research on AMMs.
Miniaturized Self‐Resonant Micro Coil Array with A Floating Structure for Wireless Multi‐Channel Transmission
Authors: Jun Byoung Ok , Kim Han‐Joon , Heo Su Jin , Kim Jonghyeun , Yang Jae Hoon , Kim Seunguk , Kim Kyungtae , Jin Woo‐Cheol , Choi Ji‐Woong , Jang Jae Eun
Published: October 2021

Micro size antennas have significant merits due to the small size effect, enabling new device concepts. However, the low‐quality factor (Q‐factor), the large size of impedance matching components, and the poor selectivity of the multi‐array design remain challenging issues. To solve these issues, a floating coil structure stacked on a loop micro‐antenna is suggested. Various floating coil designs are prepared with appropriate matching conditions at specific target frequencies, using an easy fabrication process without the need for additional space. A simple one‐loop antenna design shows a higher Q‐factor than other, more complicated designs. The micro‐sized loop antenna with the 80 µm trace width design exhibits the highest Q‐factor, around 31 within 7 GHz. The 8 different floating coil designs result in high‐frequency selectivity from 1 to 7 GHz. The highest selectivity contrast and WPT efficiency are above 7 and around 1%, respectively. Considering the size of the antenna, the efficiency is not low, mainly due to the good matching effect with the high Q‐factor of the floating coil and the loop antenna. This micro‐antenna array concept with high integration density can be applied for advanced wireless neural stimulation or in wireless pixel array concepts in flexible displays.
Dendritic Organic Electrochemical Transistors Grown by Electropolymerization for 3D Neuromorphic Engineering
Authors: Janzakova Kamila , Ghazal Mahdi , Kumar Ankush , Coffinier Yannick , Pecqueur Sébastien , Alibart Fabien
Published: October 2021

One of the major limitations of standard top‐down technologies used in today's neuromorphic engineering is their inability to map the 3D nature of biological brains. Here, it is shown how bipolar electropolymerization can be used to engineer 3D networks of PEDOT:PSS dendritic fibers. By controlling the growth conditions of the electropolymerized material, it is investigated how dendritic fibers can reproduce structural plasticity by creating structures of controllable shape. Gradual topologies evolution is demonstrated in a multielectrode configuration. A detailed electrical characterization of the PEDOT:PSS dendrites is conducted through DC and impedance spectroscopy measurements and it is shown how organic electrochemical transistors (OECT) can be realized with these structures. These measurements reveal that quasi‐static and transient response of OECTs can be adjusted by controlling dendrites’ morphologies. The unique properties of organic dendrites are used to demonstrate short‐term, long‐term, and structural plasticity, which are essential features required for future neuromorphic hardware development.
Phonon‐Related Monochromatic THz Radiation and its Magneto‐Modulation in 2D Ferromagnetic Cr2Ge2Te6
Authors: Cheng Long , Li Huiping , Lin Gaoting , Yan Jian , Zhang Lei , Yang Cheng , Tong Wei , Ren Zhuang , Zhu Wang , Cong Xin , Gao Jingjing , Tan Pingheng , Luo Xuan , sun Yuping , Zhu Wenguang , Sheng Zhigao
Published: October 2021

Searching multiple types of terahertz (THz) irradiation source is crucial for the THz technology. In addition to the conventional fermionic cases, bosonic quasi‐/particles also promise energy‐efficient THz wave emission. Here, by utilizing a 2D ferromagnetic Cr2Ge2Te6 crystal, first a phonon‐related magneto‐tunable monochromatic THz irradiation source is demonstrated. With a low‐photonic‐energy broadband THz pump, a strong THz irradiation with frequency ≈0.9 THz and bandwidth ≈0.25 THz can be generated and its conversion efficiency could even reach 2.1% at 160 K. Moreover, it is intriguing to find that such monochromatic THz irradiation can be efficiently modulated by external magnetic field below 160 K. According to both experimental and theoretical analyses, the emergent THz irradiation is identified as the emission from the phonon‐polariton and its temperature and magnetic field dependent behaviors confirm the large spin‐lattice coupling in this 2D ferromagnetic crystal. These observations provide a new route for the creation of tunable monochromatic THz source which may have great practical interests in future applications in photonic and spintronic devices.
Destructive Photon Echo Formation in Six‐Wave Mixing Signals of a MoSe2Monolayer
Authors: Hahn Thilo , Vaclavkova Diana , Bartos Miroslav , Nogajewski Karol , Potemski Marek , Watanabe Kenji , Taniguchi Takashi , Machnikowski Paweł , Kuhn Tilmann , Kasprzak Jacek , Wigger Daniel
Published: October 2021

Monolayers of transition metal dichalcogenides display a strong excitonic optical response. Additionally encapsulating the monolayer with hexagonal boron nitride allows to reach the limit of a purely homogeneously broadened exciton system. On such a MoSe2‐based system, ultrafast six‐wave mixing spectroscopy is performed and a novel destructive photon echo effect is found. This process manifests as a characteristic depression of the nonlinear signal dynamics when scanning the delay between the applied laser pulses. By theoretically describing the process within a local field model, an excellent agreement with the experiment is reached. An effective Bloch vector representation is developed and thereby it is demonstrated that the destructive photon echo stems from a destructive interference of successive repetitions of the heterodyning experiment.
Floral traits differentiate pollination syndromes and species but fail to predict the identity of floral visitors to Castilleja
Authors: Hilpman Evan T. , Busch Jeremiah W.
Published: October 2021

Premise

Animal pollination is critical to plant reproduction and may cause convergent evolution of pollination syndromes. Pollination syndromes in Castilleja have been distinguished based on floral traits and historical observations of floral visitors. Here we addressed these questions: (1) Can pollination syndromes be distinguished using floral morphological traits or volatile organic compound emissions? (2) Is there significant variation in floral traits within a pollination syndrome at the level of populations or species? (3) Do pollination syndromes predict the most frequent floral visitor to Castilleja?

Methods

Floral traits and visitation were measured for five co‐occurring Castilleja species (C. applegatei, C. linariifolia, C. miniata, C. nana, and C. peirsonii), representing three pollination syndromes (bee, fly, and hummingbird), at four sites in the Sierra Nevada Mountains. We used nonmetric multidimensional scaling (NMDS) and multiple linear regressions to address key questions in the differentiation of Castilleja and floral visitors.

Results

Our analyses revealed that both morphological traits and floral VOCs can be used to distinguish between some pollination syndromes and Castilleja species. Morphological traits defined pollination syndromes reliably, but within the hummingbird syndrome, there was also significant variation among populations and species. Pollination syndrome was a poor predictor of visitors to Castilleja.

Conclusions

Floral trait differentiation among Castilleja individuals reflects both taxonomy and pollination syndromes. Differentiation was generally more evident in morphological traits compared to VOCs. Furthermore, a priori notions of pollination syndromes in this system are overly simplistic and fail to predict which animals most frequently visit Castilleja in natural populations.
Optical Singularity Built on Tiny Holes
Authors: Zhou Changda , Mou Zhen , Lu Peiyao , Teng Shuyun
Published: October 2021

Singular optics is a branch of modern optics, and it usually refers to various singularities including phase, polarization, and energy flux singularities. Lots of excellent researches in foundation and application fields relate to optical singularities. Nanotechnology enables the manipulation of optical singularities in nanometer scale. Metasurfaces consisting of nanoscatterers have aroused intensive interest in recent years because of the ultrathin structure and the powerful light manipulation ability. Optical singular fields generated by metasurfaces built on tiny holes attract much attention. The recent research progress about the optical singular fields in nanoscale is provided here and the physical mechanism of the formation of optical singularities including phase singularity, polarization singularity, and hybrid singularity are discovered in terms of tiny holes. The beneficial reference is provided here to investigate the related works, and the applications of optical singularities in nanometer scale are promoted.
Tailoring the Electronic Structure of an Atomically Dispersed Zinc Electrocatalyst: Coordination Environment Regulation for High Selectivity Oxygen Reduction
Authors: Jia Yaling , Xue Ziqian , Yang Jun , Liu Qinglin , Xian Jiahui , Zhong Yicheng , Sun Yamei , Zhang Xiuxiu , Liu Qinghua , Yao Daoxin , Li Guangqin
Published: October 2021

Accurately regulating the selectivity of the oxygen reduction reaction (ORR) is crucial to renewable energy storage and utilization, but challenging. A flexible alteration of ORR pathways on atomically dispersed Zn sites towards high selectivity ORR can be achieved by tailoring the coordination environment of the catalytic centers. The atomically dispersed Zn catalysts with unique O‐ and C‐coordination structure (ZnO3C) or N‐coordination structure (ZnN4) can be prepared by varying the functional groups of corresponding MOF precursors. The coordination environment of as‐prepared atomically dispersed Zn catalysts was confirmed by X‐ray absorption fine structure (XAFs). Notably, the ZnN4 catalyst processes a 4 e− ORR pathway to generate H2O. However, controllably tailoring the coordination environment of atomically dispersed Zn sites, ZnO3C catalyst processes a 2 e− ORR pathway to generate H2O2 with a near zero overpotential and high selectivity in 0.1 M KOH. Calculations reveal that decreased electron density around Zn in ZnO3C lowers the d‐band center of Zn, thus changing the intermediate adsorption and contributing to the high selectivity towards 2 e− ORR.
Photokatalytische gem‐Difluorolefinierungsreaktionen durch eine formale C−C‐Kupplungs/Defluorierungsreaktion mit Diazoacetaten
Authors: Li Fang , Pei Chao , Koenigs Rene M.
Published: October 2021

Die Photolyse von Diazoalkanen zur Durchführung von Singulett‐Carbentransferreaktionen gefärbter Diazoalkane hat in letzter Zeit großes Interesse in der organischen Synthese geweckt. Hier beschreiben wir einen photokatalytischen Ansatz, der den Zugang zu Triplettcarbenen über Energietransfer ermöglicht, um hocheffiziente gem‐Difluorolefinierungsreaktionen mit α‐Trifluormethylstyrolen durchzuführen. Die Verwendung eines tertiären Amins erwies sich als entscheidend, um diesen ungewöhnlichen Reaktionsweg zu erschließen und unerwünschte Cyclopropanierungsreaktionen zu verhindern. Das Amin erleichtert zudem die finale Abstraktion von Fluorid zum gem‐Difluorolefinen (43 Beispiele, bis zu 88 % Ausbeute), was durch experimentelle und theoretische mechanistische Studien gestützt wird. Wir haben diese Synthesemethode mit einem breiten Substratspektrum untersucht, das von einfachen Olefinen und heterocyclischen Olefinen bis hin zur Funktionalisierung pharmazeutisch relevanter Bausteine reicht.
Anthraquinone Covalent Organic Framework Hollow Tubes as Binder Microadditives in Li−S Batteries
Authors: Guo Can , Liu Ming , Gao Guang‐Kuo , Tian Xi , Zhou Jie , Dong Long‐Zhang , Li Qi , Chen Yifa , Li Shun‐Li , Lan Ya‐Qian
Published: October 2021

The exploration of new application forms of covalent organic frameworks (COFs) in Li−S batteries that can overcome drawbacks like low conductivity or high loading when typically applied as sulfur host materials (mostly ≈20 to ≈40 wt % loading in cathode) is desirable to maximize their low‐density advantage to obtain lightweight, portable, or high‐energy‐density devices. Here, we establish that COFs could have implications as microadditives of binders (≈1 wt % in cathode), and a series of anthraquinone‐COF based hollow tubes have been prepared as model microadditives. The microadditives can strengthen the basic properties of the binder and spontaneously immobilize and catalytically convert lithium polysulfides, as proved by density functional calculations, thus showing almost doubly enhanced reversible capacity compared with that of the bare electrode.
Planar Chirality: A Mine for Catalysis and Structure Discovery
Authors: López Rosa , Palomo Claudio
Published: October 2021

Planar chirality is one of the most fascinating expressions of chirality, which is exploited by nature to lock three‐dimensional chiral conformations and, more recently, by chemists to create new chiral reagents, catalysts, and functional organic materials. Nevertheless, the shortage of procedures able to induce and secure asymmetry during the generation of these unique chiral entities has dissuaded chemists from exploiting their structural properties. This Minireview intends to illustrate the limited but remarkable catalytic methods that have been reported for the production of planar chirality in strained molecules and serve as a source of inspiration for the development of new unconventional procedures, which are expected to appear in the near future.
Maximizing Electroactive Sites in a Three‐Dimensional Covalent Organic Framework for Significantly Improved Carbon Dioxide Reduction Electrocatalysis
Authors: Han Bin , Jin Yucheng , Chen Baotong , Zhou Wei , Yu Baoqiu , Wei Chuangyu , Wang Hailong , Wang Kang , Chen Yanli , Chen Banglin , Jiang Jianzhuang
Published: October 2021

Synthesis of functional 3D COFs with irreversible bond is challenging. Herein, 3D imide‐bonded COFs were constructed via the imidization reaction between phthalocyanine‐based tetraanhydride and 1,3,5,7‐tetra(4‐aminophenyl)adamantine. These two 3D COFs are made up of interpenetratedptsnetworks according to powder X‐ray diffraction and gas adsorption analyses. CoPc‐PI‐COF‐3 doped with carbon black has been employed to fabricate the electrocatalytic cathode towards CO2reduction reaction within KHCO3aqueous solution, displaying the Faradaic efficiency of 88–96 % for the CO2‐to‐CO conversion at the voltage range of ca. −0.60 to −1.00 V (vs. RHE). In particular, the 3D porous structure of CoPc‐PI‐COF‐3 enables the active electrocatalytic centers occupying 32.7 % of total cobalt‐phthalocyanine subunits, thus giving a large current density (jCO) of −31.7 mA cm−2at −0.90 V. These two parameters are significantly improved than the excellent 2D COF analogue (CoPc‐PI‐COF‐1, 5.1 % and −21.2 mA cm−2).
Pullulan/polyHEMA cryogels: Synthesis, physicochemical properties, and cell viability
Authors: Ustürk Selma , Altundag Ergul Mutlu , Yilmaz Elvan
Published: October 2021

Pullulan/polyHEMA cryogels were synthesized using epichlorohydrin (ECH) and ethylene glycol dimethacrylate (EGDMA) as crosslinkers. The dried cryogels were characterized by FTIR spectroscopy for chemical structure. Thermal analysis provided evidence for different microstructures of the samples synthesized. Water contact angle (WCA) value measured as 80.56° for the pullulan/ECH/polyHEMA/polyEGDMA IPN sample reveal a more hydrophobic surface compared to the pullulan/ECH/polyHEMA graft copolymer with 18.32° WCA. Scanning electron microscopy analysis of the IPN sample gives an average pore size 72.6 μm, while the graft copolymer contains pores of average size of 100.5 μm. Swelling and degradation kinetics studied by gravimetric method reveal that the samples act as degradable hydrogels in aqueous media with equilibrium swelling capacities of 75%–100% at pH 7.4. Cell viability of pullulan/ECH/polyHEMA/polyEGDMA IPN cryogel for colon carcinoma cell lines (HCT‐116) investigated by MTT assay demonstrate that it is non‐toxic and allows cell proliferation with 159 ± 25.52% cell viability in 9 days.
Incorporation of alkyl‐functionalized silica nanoparticles into hydrophilic epoxy and hydrophobic polystyrene matrices
Authors: Lee Bo‐Young , Park Seoungju , Chung Dae‐Won , Jang Keon‐Soo
Published: October 2021

The homogeneous dispersion of nanosized fillers in a polymeric matrix is crucial for improving the mechanical and thermal properties of composites. In this study, the dispersity of silica nanoparticles (SNPs) in the hydrophilic epoxy and hydrophobic polystyrene (PS) matrices was examined. As the unmodified SNPs were hydrophilic, they dispersed well in the epoxy matrix, but agglomerated in the PS matrix. We also explored the effects of different aliphatic chain lengths (hydrophilic vs. hydrophobic: unmodified, methyl, propyl, and octyl) on the dispersity of nanoparticles in the polymer. The alkyl‐functionalized SNPs were more uniformly dispersed than the unmodified SNPs in the PS matrix. Comparing the different alkyl chains, the propyl‐functionalized SNPs exhibited the most homogeneous dispersion in the polymer, thereby increasing the mechanical properties. The octyl‐functionalized SNPs agglomerated slightly, which might be due to their chain interaction (entanglement). The size of SNPs was controlled (60, 120, and 180 nm) via sol–gel synthesis, and the SNP with the smallest diameter (60 nm) showed the slight enhancement in mechanics and dispersion compared with SNPs with diameters of 120 and 180 nm. The SNP size, hydrophilicity, functionality, and aliphatic chain length on SNP surfaces investigated in this study can be useful for various nanocomposite applications.
Rational Design of Chrysene‐Based Hybridized Local and Charge‐Transfer Molecules as Efficient Non‐Doped Deep‐Blue Emitters for Simple‐Structured Electroluminescent Devices
Authors: Chawanpunyawat Thanyarat , Chasing Pongsakorn , Nalaoh Phattananawee , Maitarad Phornphimon , Sudyodsuk Taweesak , Promarak Vinich
Published: October 2021

Herein, we present a molecular design of chrysene‐based deep‐blue emissive materials (TC, TpPC, TpXC, and TmPC), in which chrysene as a core is functionalized with different triphenylamine moieties to realize a fine‐tuning deep‐blue fluorescence with superior electroluminescent (EL) performance. The photophysical analyses and density functional theory (DFT) calculations disclose that TC, TpPC, and TpXC possess HLCT characteristics with intense deep‐blue emission in the solid‐state, good hole‐transporting ability, and high thermal and electrochemical stabilities. They are successfully employed as non‐doped emitters in simple structured OLEDs (ITO/PEDOT : PSS : NF/emitter/TPBi/LiF : Al). In particular, TC‐based device emits a deep‐blue light with an emission peak at 446 nm and CIE color coordinates of (0.148, 0.096), a maximum external quantum efficiency (EQEmax) of 4.31%, and a low turn‐on voltage of 2.8 V.
Gram‐scale synthesis of nitrogen‐doped carbon dots from locusts for selective determination of sunset yellow in food samples
Authors: Su Ke , Xiang Guoqiang , Jin Xinrong , Wang Xin , Jiang Xiuming , He Lijun , Zhao Wenjie , Sun Yaming , Cui Chen
Published: October 2021

Locust powder was converted into water‐soluble fluorescent nitrogen‐doped carbon dots (N‐CDs) with gram‐scale yield through a self‐exothermic reaction between nitric acid and diethylenetriamine (DETA) within 10 min. The morphology, elemental information, and optical properties of the N‐CDs were characterized using high‐resolution transmission electron microscopy, X‐ray photoelectron spectroscopy, and Fourier‐transform infrared, ultraviolet–visible and fluorescence spectroscopy. Spectroscopic investigation indicated that the fluorescence emission behaviour of N‐CDs is excitation wavelength dependent, with the strongest emission peak at 470 nm using a 390 nm excitation wavelength. The strong absorption peak of sunset yellow (SY) at 482 nm overlaps substantially with the blue emission peak (470 nm) of N‐CDs. This enables the fluorescence emission of N‐CDs to be obviously quenched by SY through the inner filter effect. There was a good linear relationship between the fluorescence quenching degree and the concentrations of SY within the range 0.5–40 μM. The detection limit of developed fluorescence assay for SY is 28 nM, and the relative standard deviation is 2.3% (c = 10 μM). The N‐CDs derived from locusts by the self‐exothermic reaction are highly selective and sensitive fluorescent probes for SY, which were applied to the fluorescence sensing of SY in different food samples with satisfactory results.
On the Savéant's Concerted/Stepwise Model. The Electroreduction of Halogenated Naphthalene Derivatives as a Case Study
Authors: Stefani Andrea , Giurlani Walter , Bonechi Marco , Marchetti Andrea , Preda Giovanni , Pasini Dario , Innocenti Massimo , Fontanesi Claudio
Published: October 2021

The electroreduction mechanism of 1‐Br‐2‐naphtol and 1‐I‐2‐naphtol, and of two inherently chiral BINOL derivatives ([1,1′‐Binaphthalene]‐2,2′‐diol, 6,6′‐dibromo and 1,1′‐Binaphthalene,6,6′‐dibromo‐2,2′‐dimethoxy; in the following named P1 and P2, respectively), is characterized by means of an integrated electrochemical and theoretical approach. The experimental characterization is based on cyclic voltammetry measurements. The experimental results indicate that the carbon halogen bond dissociates, following the electron uptake, with the formation of an insoluble final product (electro‐polymerization). The reduction mechanism is assessed and disassembled at a molecular level by using DFT based quantum mechanical calculations. Both steady state, equilibrium, and kinetic (molecular dynamics, MD, DRC calculations) properties are calculated. A consistent picture is obtained by the comparison between experimental and theoretical results, indicating that the carbon‐halogen bond dissociates following the first electron uptake, with a stepwise mechanism.
A stabilized finite volume element method for solving Poisson–Nernst–Planck equations
Authors: Li Jiao , Ying Jinyong
Published: October 2021

One difficulty in solving the Poisson–Nernst–Planck (PNP) equations used for studying the ion transport in channel proteins is the possible convection‐dominant problem in the Nernst–Planck equations. In this paper, to overcome this issue, considering the general mixed boundary conditions of concentration functions on the interface, a novel stabilized finite volume element method based on the standard weak formulation to solve the steady‐state PNP equations is proposed and analyzed. Numerical tests on four ion‐channel proteins served as benchmark with varying boundary conditions in a certain range show that the new stabilized technique not only improves the robustness of the new PNP solver, but also makes the computed (especially the maximal) concentration values much more reasonable.
Limited‐transpiration rate and plant conductance in a diverse sweet corn population
Authors: Jafarikouhini Nahid , Sinclair Thomas R. , Resende Marcio F. R.
Published: October 2021

Limited‐transpiration rate at elevated vapor pressure deficit (VPD) can allow soil water conservation for use during late‐season drought, but it can also result in decreased crop yields under well‐watered conditions because of restricted crop gas exchange. Previous studies with sweet corn (Zea mays L.) have found the limited‐transpiration rate was quite common among commercial cultivars even though sweet corn is commonly grown under well‐watered conditions. This study was undertaken to identify possible genetic sources of sweet corn that were not encumbered by the limited‐transpiration trait. Additionally, data were obtained to compare the plant hydraulic conductance among the lines. Among the 26 sweet corn lines included in this study, only eight did not express the limited‐transpiration trait. Four of the lines not expressing the limited‐transpiration (IL395a, IL543c, P39, and SD245) had stomata vapor conductance values over the range of tested VPD similar to the values expressed by many of the limited‐transpiration lines only at low VPD. The eight lines not expressing the limited‐transpiration trait tended to have low plant hydraulic conductance. For those lines expressing the limited‐transpiration trait, there was a correlation between the VPD at initiation of limited transpiration and plant hydraulic conductance. Expression of the limited‐transpiration traits proved, however, to be temperature sensitive in 7 of 18 tested lines expressing the trait at 32 °C because they failed to express the trait at 38 °C. The genetic variation in expression of the limited‐transpiration trait and plant hydraulic conductance identified in this study offers specific candidate inbred lines that could be used as genetic resources for improving sweet corn growth and yield for well‐watered environments.
Sustainable Routes for the Synthesis of Renewable Adipic Acid from Biomass Derivatives
Authors: Lang Man , Li Hao
Published: October 2021

Adipic acid (AA) is a key industrial dicarboxylic acid intermediate used in nylon manufacturing. Unfortunately, the traditional process technology is accompanied by serious environmental pollution. Given the growing demand for adipic acid and the desire to reduce its negative impact on the environment, considerable efforts have been devoted to developing more green and friendly routes. This Review is focused on the latest advances in the sustainable preparation of AA from biomass‐based platform molecules, including 5‐hydroxymethylfufural, glucose, γ‐valerolactone, and phenolic compounds, through biocatalysis, chemocatalysis, and the combination of both. Additionally, the development of state‐of‐the‐art catalysts for different catalytic systems systematically is discussed and summarized, as well as their reaction mechanisms. Finally, the prospects for all preparation routes are critically evaluated and key technical challenges in the development of green and sustainable processes for the manufacture of AA are highlighted. It is hoped that the green adipic acid synthesis pathways presented can provide insights and guidance for further research into other industrial processes for the production of nylon precursors in the future.
Quasi‐Parallel NiFe Layered Double Hydroxide Nanosheet Arrays for Large‐Current‐Density Oxygen Evolution Electrocatalysis
Authors: Ye Qinglan , Li Lingfeng , Li Hangyang , Gu Xiangyang , Han Boming , Xu Xuetang , Wang Fan , Li Bin
Published: October 2021

Designing advanced electrocatalysts for oxygen evolution at large current density (>500 mA cm−2) is critical to practical water splitting applications. Herein, a novel quasi‐parallel NiFe layered double hydroxide (NiFe LDH) nanosheet arrays with pattern alignment on Ni foam was developed. The initial α‐Ni(OH)2 layer induced effective coprecipitation between Ni2+ and Fe3+ for the formation of LDH phase, guaranteeing the electronic pulling effect among metal cations and enhancing the interaction between active materials and substrate for excellent adhesion and electrical conductivity. Quasi‐parallel NiFe LDH nanoarrays exhibited outstanding oxygen evolution activity with a small Tafel slope of 30.1 mV dec−1 and overpotentials of 196, 255, and 284 mV at a current density of 10, 500, and 1000 mA cm−2 in 1.0 m KOH solution, respectively, and high stability over 40 h at 750 mA cm−2. This work presents a new strategy towards fabricating electrode materials with exceptional performance.
A novel method to standardise serum IgA measurements shows an increased prevalence of IgA deficiency in young children with recurrent respiratory tract infections
Authors: Koenen Mischa H , Bosma Madeleen , Roorda Udo A , Wopereis Fabiënne MY , Roos Anja , van der Vries Erhard , Bogaert Debby , Sanders Elisabeth AM , Boes Marianne , Heidema Jojanneke , van Montfrans Joris M , Balemans Walter AF , van Holten Thijs C , Verhagen Lilly M
Published: October 2021

Objectives

While physicians are often confronted with immunoglobulin A (IgA) deficiency in children with recurrent infections, the clinical relevance of this finding is unclear. Large‐scale studies examining the significance of IgA deficiency in children are hampered by differences in techniques for measuring IgA and the physiological increase of IgA with age. Both result in a variety of reference values used for diagnosing IgA deficiency. We propose a new laboratory‐independent method to accurately compare IgA measurements in children of varying ages.

Methods

We present a method to standardise IgA values for age and laboratory differences. We applied this method to a multicentre case–control study of children under the age of seven suffering from recurrent respiratory tract infections (rRTI, cases) and children who had IgA measured as part of coeliac disease screening (controls). We defined IgA deficiency as serum IgA measurements < 2.5% for age‐specific reference values.

Results

We developed reference values for IgA for seven age groups and five different laboratory assays. Using these reference values, IgA measurements from 417 cases and 224 controls were standardised to compare groups. In children aged 2 years and older, IgA deficiency was observed in 2.9% (7/242) of cases and 0% (0/189) of controls (P = 0.02).

Conclusion

We present a method to compare IgA values in cohorts that vary in age and laboratory assay. This way, we showed that IgA deficiency was more prevalent in children with rRTI compared with controls. This implicates that IgA deficiency may be a clinically relevant condition, even in young children.
The role of olfactory cues in mother–pup, groupmate, and sex recognition of lesser flat‐headed bats, Tylonycteris pachypus
Authors: Liang Jie , Yang Jian , Chen Yi , Zhang Libiao
Published: October 2021

Tylonycteris pachypus is a gregarious bat species with tens of individuals in a colony. The mechanisms by which mother bats recognize their pups and adult bats recognize each other are not clear. We hypothesized that such recognition is achieved by chemical discrimination and performed experiments to test the hypothesis. Results showed that mother bats were much more attracted to the scent from their own pups. For adult bats, females were attracted to the scent from both male and female groupmates but had a higher preference to the scent from female than from male groupmates. Male bats were much more attracted to the scent from male groupmates while showed no preference to the scent from female groupmates. Within a group, both female and male bats had no difference in preference to the scent from the same or opposite sex. These results suggest that mother–pup and groupmate recognition of T. pachypus can be achieved by olfactory cues.
Plant–herbivore interactions: Combined effect of groundwater level, root vole grazing, and sedge silicification
Authors: Borowski Zbigniew , Zub Karol , Sulwiński Marcin , Suska‐Malawska Małgorzata , Konarzewski Marek
Published: October 2021

Accumulation of silica (Si) by plants can be driven by (1) herbivory pressure (and therefore plant–herbivore interactions), (2) geohydrological cycles, or (3) a combination of (1) and (2), with (1–3) possibly affecting Si concentration with a 1‐year delay.

To identify the relative significance of (1–3), we analyzed the concentration of Si in fibrous tussock sedge (Carex appropinquata), the population density of the root vole (Microtus oeconomus), and the groundwater level, over 11 years.

The largest influence of autumn Si concentration in leaves (Sileaf) was on the level of the current‐year groundwater table, which was positive and accounted for 13.3% of its variance. The previous year's vole population density was weakly positively correlated with Sileaf, and it alone explained 9.5% of its variance.

The only variable found to have a positive, significant effect on autumn Si concentration in rhizomes (Sirhiz) was the current‐year spring water level, explaining as much as 60.9% of its variance.

We conclude that the changes in Si concentration in fibrous tussock sedge are predominantly driven by hydrology, with vole population dynamics being secondary.

Our results provide only partial support for the existence of plant–herbivore interactions, as we did not detect the significant effects of Si tussock concentration on the vole density dynamics. This was mainly due to the low level of silicification of sedges, which was insufficient to impinge herbivores.

Future studies on plant–herbivore interactions should therefore aim at disentangling whether anti‐herbivore protection is dependent on threshold values of herbivore population dynamics. Furthermore, studies on Si accumulation should focus on the effect of water‐mediated Si availability.
High‐Voltage Aqueous Zinc Batteries Achieved by Tri‐functional Metallic Bipolar Electrodes
Authors: Liu Chang , Chi Xiaowei , Yang Cheng , Liu Yu
Published: October 2021

Aqueous rechargeable zinc batteries are very attractive for energy storage applications due to their low cost and high safety. However, low operating voltages limit their further development. For the first time, this work proposes a unique approach to increase the voltages of aqueous zinc batteries by using tri‐functional metallic bipolar electrode with good electrochemical activity and ultrahigh electronic conductivity, which not only participates in redox reactions, but also functions as an electrical highway for charge transport. Furthermore, bipolar electrode can replace expensive ion selective membrane to separate electrolytes with different pH; thus, redox couples with higher potential in acid condition and couple with lower potential in alkaline condition can be employed together, leading to high voltages of aqueous zinc batteries. Herein, two types of metallic bipolar electrodes of Cu and Ag are utilized based on three kinds of aqueous zinc batteries: Zn–MnO2, Zn–I2, and Zn–Br2. The voltage of aqueous Zn–MnO2 battery is raised to 1.84 V by employing one Cu bipolar electrode, which shows no capacity attenuation after 3500 cycles. Moreover, the other Ag bipolar electrode can be adopted to successfully construct Zn–I2 and Zn–Br2 batteries exhibiting much higher voltages of 2.44 and 2.67 V, which also show no obvious capacity degradation for 1000 and 800 cycles, representing decent cycle stability. Since bipolar electrode can be applied in a large family of aqueous batteries, this work offers an elaborate high‐voltage concept based on tri‐functional metallic bipolar electrode as a model system to open a door to explore high‐voltage aqueous batteries.
Green finance for soft power: An analysis of China's green policy signals and investments in the Belt and Road Initiative
Authors: Nedopil Christoph
Published: October 2021

In this paper, I study why and how China uses green overseas finance in its Belt and Road Initiative (BRI) to build soft power. I apply Miskimmon et al.’s framework, which postulates that soft power is built on ‘signals' and ‘action’: I study eleven relevant Chinese BRI government and sector‐led signals in green BRI development and analyze Chinese green versus non‐green energy investments as actions. I find that Chinese regulators and financial institutions have provided multiple signals for greening finance in the BRI, while green finance action is insufficient with continued sponsoring of non‐green investments. The paper concludes that green finance is a tool for China to build soft power in the BRI, but it is applied insufficiently due to a lack of green finance action. The paper also finds that insufficient strength of soft power signals can lead to a dichotomy between soft power signals and action with possible negative consequences for soft power.
Mortality risk in chronic Chagas cardiomyopathy: a systematic review and meta‐analysis
Authors: Chadalawada Sindhu , Rassi Anis , Samara Omar , Monzon Anthony , Gudapati Deepika , Vargas Barahona Lilian , Hyson Peter , Sillau Stefan , Mestroni Luisa , Taylor Matthew , da Consolação Vieira Moreira Maria , DeSanto Kristen , Agudelo Higuita Nelson I. , Franco‐Paredes Carlos , Henao‐Martínez Andrés F.
Published: October 2021

Aims

This study aimed to estimate the annual mortality risk and its determinants in chronic Chagas cardiomyopathy.

Methods and results

We conducted a systematic search in MEDLINE, Web of Science Core Collection, Embase, Cochrane Library, and LILACS. Longitudinal studies published between 1 January 1946 and 24 October 2018 were included. A random‐effects meta‐analysis using the death rate over the mean follow‐up period in years was used to obtain pooled estimated annual mortality rates. Main outcomes were defined as all‐cause mortality, including cardiovascular, non‐cardiovascular, heart failure, stroke, and sudden cardiac deaths. A total of 5005 studies were screened for eligibility. A total of 52 longitudinal studies for chronic Chagas cardiomyopathy including 9569 patients and 2250 deaths were selected. The meta‐analysis revealed an annual all‐cause mortality rate of 7.9% [95% confidence interval (CI): 6.3–10.1; I2 = 97.74%; T2 = 0.70] among patients with chronic Chagas cardiomyopathy. The pooled estimated annual cardiovascular death rate was 6.3% (95% CI: 4.9–8.0; I2 = 96.32%; T2 = 0.52). The annual mortality rates for heart failure, sudden death, and stroke were 3.5%, 2.6%, and 0.4%, respectively. Meta‐regression showed that low left ventricular ejection fraction (coefficient = −0.04; 95% CI: −0.07, −0.02; P = 0.001) was associated with an increased mortality risk. Subgroup analysis based on American Heart Association (AHA) classification revealed pooled estimate rates of 4.8%, 8.7%, 13.9%, and 22.4% (P < 0.001) for B1/B2, B2/C, C, and C/D stages of cardiomyopathy, respectively.

Conclusions

The annual mortality risk in chronic Chagas cardiomyopathy is substantial and primarily attributable to cardiovascular causes. This risk significantly increases in patients with low left ventricular ejection fraction and those classified as AHA stages C and C/D.
Levosimendan‐induced venodilation is mediated by opening of potassium channels
Authors: Burkhoff Daniel , Rich Stuart , Pollesello Piero , Papp Zoltán
Published: October 2021

Unique vascular responses adhere to the cardiovascular efficacy of the inodilator levosimendan. In particular, selective venodilation appears to explain its clinical benefit during pulmonary hypertension complicated by heart failure with preserved ejection fraction. Vasodilators increase vessel diameter in various parts of the vascular system to different degrees and thereby influence blood pressure, its distribution, and organ perfusion depending on their mechanisms of action. Levosimendan and its long‐lived active metabolite OR‐1896 mobilize a set of vasodilatory mechanisms, that is, the opening of the ATP‐sensitive K+ channels and other K+ channels on top of a highly selective inhibition of the phosphodiesterase III enzyme. A vessel‐specific combination of the above vasodilator mechanisms—in concert with cardiac effects and cardiovascular reflex regulations—illustrates the pharmacological profile of levosimendan in various cardiovascular disorders. While levosimendan has been known to be an inotrope, its properties as an activator of ATP‐sensitive K+ channels have gone largely ignored with respect to clinical applications. Here, we provide a summary of what is known about the ATP‐sensitive K+ channel properties in preclinical studies and now for the first time, its ATP‐sensitive K+ channel properties in a clinical trial.
Efficacy and safety of intermittent repeated levosimendan infusions in advanced heart failure patients: the LAICA study
Authors: García‐González Martín J. , Aldea Perona Ana , Lara Padron Antonio , Morales Rull José Luis , Martínez‐Sellés Manuel , de Mora Martin Manuel , López Díaz Javier , López Fernandez Silvia , Ortiz Oficialdegui Pilar , Jiménez Sosa Alejandro
Published: October 2021

Aims

The aim of the LAICA study was to evaluate the long‐term effectiveness and safety of intermittent levosimendan infusion in patients with advanced heart failure (AdHF).

Methods and results

This was a multicentre, randomized, double‐blind, placebo‐controlled clinical trial of intermittent levosimendan 0.1 μg/kg/min as a continuous 24‐h intravenous infusion administered once monthly for 1 year in patients with AdHF. The primary endpoint [incidence of rehospitalization (admission to the emergency department or hospital ward for >12 h) for acute decompensated HF or clinical deterioration of the underlying HF] occurred in 23/70 (33%) of the levosimendan group (Group I) and 12/27 (44%) of the placebo group (Group II) (P = 0.286). The incidence of hospital readmissions for acute decompensated HF (Group I vs. Group II) at 1, 3, 6, and 12 months was 4.2% vs. 18.2% (P = 0.036); 12.8% vs. 33.3% (P = 0.02); 25.7% vs. 40.7% (P = 0.147); 32.8% vs. 44.4% (P = 0.28), respectively. In a secondary pre‐specified time‐to‐event analysis no differences were observed in admission for acute decompensated HF between patients treated with levosimendan compared with placebo (hazard ratio 0.66; 95% CI, 0.32–1.32; P = 0.24). Cumulative incidence for the aggregated endpoint of acute decompensation of HF and/or death at 1 and 3 months were significatively lower in the levosimendan group than in placebo group [5.7% vs. 25.9% (P = 0.004) and 17.1% vs. 48.1% (P = 0.001), respectively], but not at 6 and 12 months [34.2% vs. 59.2% (P = 0.025); 41.4% vs. 66.6% (P = 0.022), respectively]. Survival probability was significantly higher in patients who received levosimendan compared with those who received placebo (log rank: 4.06; P = 0.044). There were no clinically relevant differences in tolerability between levosimendan and placebo and no new safety signals were observed.

Conclusions

In our study, intermittent levosimendan in patients with AdHF produced a statistically non‐significant reduction in the incidence of hospital readmissions for acute decompensated HF, a significantly lower cumulative incidence of acute decompensation of HF and/or death at 1 and 3 month of treatment and a significant improvement in survival during 12 months of treatment.
The benefits of sacubitril–valsartan in patients with acute myocardial infarction: a systematic review and meta‐analysis
Authors: Xiong Bo , Nie Dan , Qian Jun , Yao Yuanqing , Yang Gang , Rong Shunkang , Zhu Que , Du Yun , Jiang Yonghong , Huang Jing
Published: October 2021

Aims

We aimed to investigate whether sacubitril–valsartan could further improve the prognosis, cardiac function, and left ventricular (LV) remodelling in patients following acute myocardial infarction (AMI).

Methods and results

We searched the PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) from inception to 10 May 2021 to identify potential articles. Randomized controlled trials (RCTs) meeting the inclusion criteria were included and analysed. Thirteen RCTs, covering 1358 patients, were analysed. Compared with angiotensin‐converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB), sacubitril–valsartan did not significantly reduced the cardiovascular mortality [risk ratio (RR) 0.65, 95% confidence interval (CI) 0.22 to 1.93, P = 0.434] and the rate of myocardial reinfarction (RR 0.65, 95% CI 0.29 to 1.46, P = 0.295) of patients following AMI, but the rate of hospitalization for heart failure (HF) (RR 0.48, 95% CI 0.35 to 0.66, P < 0.001) and the change of LV ejection fraction (LVEF) [weighted mean difference (WMD) 5.49, 95% CI 3.62 to 7.36, P < 0.001] were obviously improved. The N‐terminal pro‐brain natriuretic peptide (NT‐ProBNP) level (WMD −310.23, 95% CI −385.89 to −234.57, P < 0.001) and the LV end‐diastolic dimension (LVEDD) (WMD −3.16, 95% CI −4.59 to −1.73, P < 0.001) were also significantly lower in sacubitril–valsartan group than in ACEI/ARB group. Regarding safety, sacubitril–valsartan did not increase the risk of hypotension, hyperkalaemia, angioedema, and cough.

Conclusions

This meta‐analysis suggests that early administration of sacubitril–valsartan may be superior to conventional ACEI/ARB to decrease the risk of hospitalization for HF, improve the cardiac function, and reverse the LV remodelling in patients following AMI.
The National Comprehensive Governance for epilepsy prevention and control in China
Authors: Li Shichuo , Wang Yuping , Wang Wenzhi , Zhou Dong , Zhang Hui , Duan Lirong , Ding Ding , Jiang Yuwu , Wang Yi , Liu Xiaoyan , Hong Zhen
Published: October 2021

This article describes “the national comprehensive governance for epilepsy prevention and control in China” as an example of a strategic working program for the prevention and control of epilepsy at a national level. The comprehensive governance includes 10 key elements: epilepsy centers' consortium and three tier diagnosis/treatment network; rural and urban community projects on epilepsy care; awareness, publicity, and education; big data platform; development of telemedicine; team and capacity building; strengthening epilepsy research; developing and strengthening partnership; coordination with government; and international collaboration.
Biomaterials and nanomedicine for bone regeneration: Progress and future prospects
Authors: Zhou Jun , Zhang Zhongyang , Joseph John , Zhang Xingcai , Ferdows Bijan Emiliano , Patel Dylan Neal , Chen Wei , Banfi Giuseppe , Molinaro Roberto , Cosco Donato , Kong Na , Joshi Nitin , Farokhzad Omid C. , Corbo Claudia , Tao Wei
Published: October 2021

Bone defects pose a heavy burden on patients, orthopedic surgeons, and public health resources. Various pathological conditions cause bone defects including trauma, tumors, inflammation, osteoporosis, and so forth. Auto‐ and allograft transplantation have been developed as the most commonly used clinic treatment methods, among which autologous bone grafts are the golden standard. Yet the repair of bone defects, especially large‐volume defects in the geriatric population or those complicated with systemic disease, is still a challenge for regenerative medicine from the clinical perspective. The fast development of biomaterials and nanomedicine favors the emergence and promotion of efficient bone regeneration therapies. In this review, we briefly summarize the progress of novel biomaterial and nanomedical approaches to bone regeneration and then discuss the current challenges that still hinder their clinical applications in treating bone defects.