bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconstructed Water Oxidation Electrocatalysts: The Impact of Surface Dynamics on Intrinsic Activities
Authors: Selvam N. Clament Sagaya , Du Lijie , Xia Bao Yu , Yoo Pil J. , You Bo
Published: October 2020

Electroreduction of small molecules such as H2O, CO2, and N2 for producing clean fuels or valuable chemicals provides a sustainable approach to meet the increasing global energy demands and to alleviate the concern on climate change resulting from fossil fuel consumption. On the path to implement this purpose, however, several scientific hurdles remain, one of which is the low energy efficiency due to the sluggish kinetics of the paired oxygen evolution reaction (OER). In response, it is highly desirable to synthesize high‐performance and cost‐effective OER electrocatalysts. Recent advances have witnessed surface reconstruction engineering as a salient tool to significantly improve the catalytic performance of OER electrocatalysts. In this review, recent progress on the reconstructed OER electrocatalysts and future opportunities are discussed. A brief introduction of the fundamentals of OER and the experimental approaches for generating and characterizing the reconstructed active sites in OER nanocatalysts are given first, followed by an expanded discussion of recent advances on the reconstructed OER electrocatalysts with improved activities, with a particular emphasis on understanding the correlation between surface dynamics and activities. Finally, a prospect for clean future energy communities harnessing surface reconstruction‐promoted electrochemical water oxidation will be provided.
Isotope Effect in the Magneto‐Optoelectronic Response of Organic Light‐Emitting Diodes Based on Donor–Acceptor Exciplexes
Authors: Liu Xiaojie , Popli Henna , Kwon Ohyun , Malissa Hans , Pan Xin , Park Bumwoo , Choi Byoungki , Kim Sunghan , Ehrenfreund Eitan , Boehme Christoph , Vardeny Z. Valy
Published: October 2020

The isotope effect is studied in the magneto‐electroluminescence (MEL) and pulsed electrically detected magnetic resonance of organic light‐emitting diodes based on thermally activated delayed fluorescence (TADF) from donor–acceptor exciplexes that are either protonated (H) or deuterated (D). It is found that at ambient temperature, the exchange of H to D has no effect on the spin‐dependent current and MEL responses in the devices. However, at cryogenic temperatures, where the reverse intersystem crossing (RISC) from triplet to singlet exciplex diminishes, a pronounced isotope effect is observed. These results show that the RISC process is not governed by the hyperfine interaction as thought previously, but proceeds through spin‐mixing in the triplet exciplex. The observations are corroborated by electrically detected transient spin nutation experiments that show relatively long dephasing time at ambient temperature, and interpreted in the context of a model that involves exchange and hyperfine interactions in the spin triplet exciplex. These findings deepen the understanding of the RISC process in TADF materials.
Hydrogen‐Bonding‐Assisted Cationic Aqua Palladium(II) Complex Enables Highly Efficient Asymmetric Reactions in Water
Authors: Kitanosono Taku , Hisada Tomoya , Yamashita Yasuhiro , Kobayashi Shū
Published: October 2020

Metal‐bound water molecules have recently been recognized as a new facet of soft Lewis acid catalysis. Herein, a chiral palladium aqua complex was constructed that enables carbon–hydrogen bonds of indoles to be functionalized efficiently. We embraced a chiral 2,2′‐bipyridine as both ligand and hydrogen‐bond donor to configure a robust, yet highly Lewis acidic, chiral aqua complex in water. Whereas the enantioselectivity could not be controlled in organic solvents or under solvent‐free conditions, the use of aqueous environments allowed the σ‐indolylpalladium intermediates to react efficiently in a highly enantioselective manner. This work thus describes a potentially powerful new approach to the transformation of organometallic intermediates in a highly enantioselective manner under mild reaction conditions.
Structural Basis of the Modulation of the Voltage‐Gated Calcium Ion Channel Cav1.1 by Dihydropyridine Compounds**
Authors: Gao Shuai , Yan Nieng
Published: October 2020

1,4‐Dihydropyridines (DHP), the most commonly used antihypertensives, function by inhibiting the L‐type voltage‐gated Ca2+ (Cav) channels. DHP compounds exhibit chirality‐specific antagonistic or agonistic effects. The structure of rabbit Cav1.1 bound to an achiral drug nifedipine reveals the general binding mode for DHP drugs, but the molecular basis for chiral specificity remained elusive. Herein, we report five cryo‐EM structures of nanodisc‐embedded Cav1.1 in the presence of the bestselling drug amlodipine, a DHP antagonist (R)‐(+)‐Bay K8644, and a titration of its agonistic enantiomer (S)‐(−)‐Bay K8644 at resolutions of 2.9–3.4 Å. The amlodipine‐bound structure reveals the molecular basis for the high efficacy of the drug. All structures with the addition of the Bay K8644 enantiomers exhibit similar inactivated conformations, suggesting that (S)‐(−)‐Bay K8644, when acting as an agonist, is insufficient to lock the activated state of the channel for a prolonged duration.
Investigating the effect of silver nanorods embedded in polydimethylsiloxane matrix using nanoindentation and its use for flexible electronics
Authors: Maithani Yogita , Mehta Bodh Raj , Singh Jitendra Pratap
Published: October 2020

The stretchable electrodes with excellent flexibility, electrical conductivity, and mechanical durability are the most fundamental components in the emerging and exciting field of flexible electronics. This article proposes a method for fabrication of such a stretchable electrode by embedding silver nanorods (AgNRs) into a polydimethylsiloxane (PDMS) matrix that is grown by a unique glancing angle deposition technique. The surface, mechanical, and electrical properties of PDMS are significantly changed after embedding the AgNRs in it. The results show that surface roughness and polarity increase after AgNRs are embedded in the PDMS matrix. Elastic modulus (E) and hardness (H) decrease with an increase in the indentation load as a result of the indentation depth effect. Due to strong interfacial adhesion of AgNRs embedded in the PDMS matrix, the E and H of nanocomposite are increased by 167.6 and 93.3% compared with PDMS film, respectively. Furthermore, the AgNRs‐PDMS film has an electrical resistivity value in the order of 10−7 Ωm. It remains conductive during various mechanical strains such as bending, twisting, and stretching, which is demonstrated using a light‐emitting diode circuit. Simultaneously, the antimicrobial activity of silver could make it a promising candidate for wearable electronics.
Quaternized poly (2,6‐dimethyl‐1,4‐phenylene oxide) crosslinked by tertiary amine and siloxane for anion exchange membranes
Authors: Ding Ao , Zhou Jinyue , Cheng Xiangze , Shen Chunhui , Gao Shanjun
Published: October 2020

A series of tertiary amine and siloxane crosslinked composite anion exchange membranes were prepared by incorporating 2‐(3,4‐epoxycyclohexyl) ethyltrimethoxysilane (EHTMS) and N,N,N′,N′‐Tetramethyl‐1,6‐hexanediamine (TMHDA) into N‐Methyldiethanolamine (MDEA)‐functionalized poly (2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) backbone via sol‐gel process. The resultant membranes named as AEM‐X (X = 1, 2, 3, 4), which own a three‐dimensional (3D) cross‐linking structure, exhibit superior swelling resistance, mechanical properties, even the thermal stability is up to 220°C. Compared with AEM‐1 (contains no crosslinker), the swelling ratio of AEM‐2 obviously decreases by 10.2% at 80°C, while the OH− conductivity of AEM‐2 has a merely 1.9% decline (20.6 mS cm−1) at 80°C and can maintain 67% of its initial value in a 2 M aqueous NaOH at 80°C for 240 h. The simultaneous introduction of inorganic siloxane and organic linear crosslinker provides a new idea for the preparation of anion exchange membranes with largely improvement in dimensional stability and alkali resistance while the ionic conductivity is kept at comparatively high level.
An efficient protocol for functional studies of apple transcription factors using a glucocorticoid receptor fusion system
Authors: Estevan Joan , Gómez‐Jiménez Sara , Falavigna Vítor da Silveira , Camuel Alicia , Planel Lisa , Costes Evelyne , Andrés Fernando
Published: October 2020

Premise

We report a protocol for studying the function of apple (Malus ×domestica) transcription factors based on the glucocorticoid receptor (GR) system, which allows the dexamethasone (DEX)‐mediated activation of plant transcription factors to monitor the expression levels of their potential target genes.

Methods and Results

Apple leaves are transformed with a vector that allows the expression of the studied transcription factor (i.e., FLOWERING LOCUS C [MdFLC]) fused to GR. Calli derived from the transformed leaves are treated with DEX and cycloheximide, a protein synthesis inhibitor. Compared with other methods, combining the GR system with cycloheximide treatments enables the differentiation between direct and indirect transcription factor target genes. Finally, the expression levels of putative MdFLC target genes are quantified using quantitative reverse transcription PCR.

Conclusions

We demonstrate the efficiency of our GR system to study the function of apple transcription factors. This method is accessible to any laboratory familiar with basic molecular cloning procedures and the apple leaf–mediated agro‐transformation technique.
Topographical and structural characterization of the V1–V2 transition zone in the visual cortex of the long‐finned pilot whale Globicephala melas (Traill, 1809)
Authors: Graïc Jean‐Marie , Peruffo Antonella , Grandis Annamaria , Cozzi Bruno
Published: October 2020

The visual system of cetaceans is at best poorly understood. With a handful of electrophysiological studies and a limited number of histological preparations from well‐preserved specimen, the investigation of the principles underlying the cortical organization in cetaceans remains a challenge. In the course of our current investigation, we identified the transition from V2 to V1 in the long‐finned pilot whale Globicephala melas, only recognizable through immunocytochemistry, and a similar if not homologue transition in the sheep Ovis aries. Our results emphasize the importance of differential pattern recognition in which the application of different markers uncovers a diversity in a delphinid’s cortex, formerly widely considered as uniform and archetypal. In fact, the evidence that we present suggests the existence of relatively unacknowledged areas beyond the well‐known sensory territories in cetaceans.
Non‐minimal state space model predictive control using Laguerre functions for reference tracking
Authors: Liu Meng , Wu Hao , Wang Jun , Wang Changlin
Published: October 2020

This paper presents a new design of model predictive control which combines non‐minimal state space (NMSS) and Laguerre functions. The utilization of NMSS omits the observer design process and brings convenience to multi‐input, multi‐output systems with time delay. But the dimensions of NMSS are high, which is harmful to online computation. The use of Laguerre functions helps reduce the data required in the optimization algorithm and makes up for the deficiency of NMSS. A modified solution for the optimal tracking problem using NMSS and Laguerre functions is proposed. Although the choice of the parameters in Laguerre functions needs experiments and experience, the method presented in this paper brings convenience to MPC design. Simulation results show that this approach not only reduces the computing effort without sacrificing the control performance significantly, but also has a good robustness to interference when tracking.
Study of the Synthesis and Properties of Ir(III) Complexes Based on Phosphine Carbonylimide Derivative as Auxiliary Ligand
Authors: Guo Qing‐Mei , Huang Guo‐Li , Yin Xin‐Ying , Bian Jian‐Jian , Li Xiao‐Mei , Teng Ming‐Yu
Published: October 2020

Three iridium complexes of (dfppy)2Ir(DAPB), (dfppy)2Ir(DAPB), and (dfppy)2Ir(DAPB) were synthesized by using phosphine carbonylimide derivative as auxiliary ligand and fluoro−/trifluoromethyl substituted 2‐phenylpyridine derivatives as primary ligands. Their quantum efficiency range from 19.4% to 38.5%, and show strong rigidochromic effect. The maximum emission wavelengths of solid‐state fluorescence have remarkable red shifts from 39 to 55 nm compared with these in CH2Cl2.
Pharmacokinetics and tissue distribution study of obtusifolin in rats by liquid chromatography–tandem mass spectrometry
Authors: Huang Zhu , Sun Qiao , Hao Wenwen , Zhao Junyu
Published: October 2020

This paper reports the validation of an assay for obtusifolin based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) and its application to a preclinical pharmacokinetic study in rats. After sample preparation of plasma and tissue homogenates by protein precipitation, the analyte and internal standard (IS) were separated by a reversed‐phase chromatographic system in a run time of 5.0 min and detected by negative ion electrospray ionization followed by selected reaction monitoring of the precursor‐to‐product ion transitions at m/z 283.0–268.1 for obtusifolin and m/z 329.0–314.1 for IS. The assay was linear in the concentration range 1.0–500 ng/ml with the LLOQ of 1.0 ng/ml. In the pharmacokinetic study of an intragastric administration of 1.3 mg/kg obtusifolin, the maximum plasma concentration of obtusifolin was 152.5 ± 62.3 ng/ml, reached at 0.39 ± 0.17 h. The AUC0–t and AUC0–∞ were 491.8 ± 256.7 and 501.7 ± 256.7 ng × h/ml, respectively, with an elimination half‐life of 3.1 ± 0.7 h. Obtusifolin was rapidly distributed into tissues, with the highest distribution in the liver and less in the brain. These results will give some insights for further pharmacological investigation of obtusifolin.
Plasma amino acid metabolomic pattern in heart failure patients with either preserved or reduced ejection fraction: The relation to established risk variables and prognosis
Authors: Saleem Tahia H. , Algowhary Magdy , Kamel Fatma Elzahraa M , El‐Mahdy Reham I
Published: October 2020

Communication between amino acids (AAs) and heart failure (HF) is unclear. We evaluate the plasma metabolomic profile of AAs in HF and its subgroups and association with clinical features. This is a case–control study in which 90 patients with HF, 63 with reduced ejection fraction (HFrEF) and 27 with preserved ejection fraction (HFpEF), were compared with 60 controls. The quantitative measurement of plasma concentrations of AA metabolites was performed using an AA analyzer. Compared with controls, HF patients had significantly higher levels of nine AAs and significantly lower levels of seven AAs. Leu, phenylalanine (Phe), and methionine (Met) were the independent predictors of HF that remained significant after adjustment for confounding factors in multivariate analysis. There was a significant difference in 10 AAs and some clinical features between HFpEF and HFrEF. The plasma levels of six AAs were significantly increased across the different New York Heart Association (NYHA) classes, (class II, class III, class IV) but they were not predictor of reduced EF and NYHA in multivariate regression analysis. There were significant associations between Leu, Phe, and Met with cardiovascular risk variables and prognosis. In conclusion, plasma Leu, Phe, and Met provide early prediction and prognostic values of HF. The plasma AAs could have significant impact on the risk‐stratifying HFrEF and HFpEF and NYHA functional class but do not predict them.
Comparative pharmacokinetics of seven bioactive components in normal, sham‐operated, and myocardial ischemia–reperfusion injury rats after oral administration of the Salvia Miltiorrhiza–Moutan Cortex herb pair
Authors: Yang Haotian , Qiu Bo , Xue Chaojun , Guo Caihui , Dong Zhanjun
Published: October 2020

Recently the Salvia Miltiorrhiza–Moutan Cortex (SM‐MC) herb pair is considered as a promising Chinese medicinal mixture exhibiting a range of pharmacological activities, including treating cardiovascular disease due to its unique composition. In this study, we conducted the comparative pharmacokinetic analysis of seven main bioactive components of SM‐MC in a different model rat. A straightforward ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) strategy that could simultaneously evaluate the levels of seven compounds was used to ensure the reliability of these pharmacokinetic analyses in rat plasma. The rat plasma samples were collected from normal, sham‐operated, and myocardial ischemia–reperfusion injury (MIRI) groups at predetermined time points after the administration of SM‐MC. The main pharmacokinetic parameters were detected and calculated. We successfully assessed the maximum concentration (Cmax), time to Cmax (Tmax), the elimination rate constant (λz), total half‐life (t1/2), total body clearance (CL), and the area under the concentration–time curve from 0 to last sampling time (AUC0–t) and extrapolated to infinity (AUC0–∞). To sum up, an optimized UPLC‐MS/MS approach that could be used to rapidly, simultaneously, and sensitively detect seven bioactive compounds derived from SM‐MC extract preparations was successfully developed, which may offer a pharmacokinetic basis for preclinical and clinical studies of SM‐MC herb pair for treating MIRI.
Verbascum nigrum: Cytotoxicity Evaluation in A431 Epidermoid Carcinoma Cells and Untargeted LC‐HR‐MS/MS Metabolite Profiling
Authors: Iliescu Iolanda Alca , Peter Samuel , Albert Ina , Skalicka‐Woźniak Krystyna , Miron Anca , Luca Simon Vlad , Wolfram Evelyn
Published: October 2020

The crude methanolic extract obtained from Verbascum nigrum aerial parts (VNE) and its six fractions (VNF1–VNF6) were initially screened regarding their effects on the viability of immortalized HaCaT keratinocytes and A431 epidermoid carcinoma cells (MTT assay, 24 h). None of the tested samples affected the viability of HaCaT cells in a concentration range of 25–150 μg/mL. VNE and VNF4 exhibited significant cytotoxic effects in A431 cells, with IC50 values of 81.92 and 12.27 μg/mL, respectively; the selectivity index was higher than 10 for VNF4. The untargeted LC/HR‐MS/MS metabolite profiling led to the tentative annotation of a total number of 23 compounds. Of these, VNE comprised mainly iridoid glycosides (harpagoside, laterioside, acylated aucubin derivatives), whereas VNF4 showed a high abundance of triterpene saponin glycosides (ilwensisaponins A and C, songarosaponins A and B), constituents known for their selective cytotoxic potential.
Highly Active and Stable Palladium Catalysts Supported on Surface‐modified Ceria Nanowires for Lean Methane Combustion
Authors: Wu Mingwei , Li Wenzhi , Ogunbiyi Ajibola T. , Guo Ge , Xue Fengyang , Chen Kun , Zhang Baikai
Published: October 2020

An efficient strategy was presented to synthesize highly active palladium catalyst supported on ceria nanowires modified by organosilanes (abbreviated as Pd/CeO2NWs@SiO2) for lean methane combustion. It is found that such a surface‐modified strategy can significantly improve the dispersion of surface palladium species and strengthen the concentration of active surface‐adsorbed oxygen species via reconstructing the surface microenvironment, invoking an efficient performance for methane oxidation. Under the space velocity of 60,000 mLg−1h−1, 0.5 wt% Pd/CeO2NWs@SiO2 displayed extraordinary catalytic activity with 90 % conversion rate at a temperature of around 327 °C, far lower than that of pristine Pd/CeO2NWs (378 °C) under the same conditions. What's more, unexpected stability was observed under high temperature and the presence of water vapor conditions owing to the intense metal support interaction of Pd/CeO2NWs@SiO2 catalyst. The possible reaction mechanism of lean methane oxidation was probed by in situ DRIFT spectra. It is observed that the pivotal intermediate products (carbonate and carbon oxygenates) generated on Pd/CeO2NWs@SiO2 surface are more readily decomposed into CO2. Importantly, the silicon hydroxyl groups (Si−OH) formed during the reaction can efficiently restrict the generation of the stable Pd(OH)x phase and release more active sites to facilitate the catalytic performance. This study provides a convenient method to design the highly reactive and durable palladium‐based catalyst for methane combustion.
Freestanding Nanolayers of a Wide‐Gap Topological Insulator through Liquid‐Phase Exfoliation
Authors: Lê Anh Mai , Potapov Pavel , Wolf Daniel , Lubk Axel , Glatz Bernhard , Fery Andreas , Doert Thomas , Ruck Michael
Published: October 2020

The layered salt Bi14Rh3I9 is a weak three‐dimensional (3D) topological insulator (TI), that is, a stack of two‐dimensional (2D) TIs. It has a wide non‐trivial band gap of 210 meV, which is generated by strong spin‐orbit coupling, and possesses protected electronic edge‐states. In the structure, charged layers of
(Bi4Rh)3I]2+ honeycombs and
Bi2I8]2− chains alternate. The non‐trivial topology of Bi14Rh3I9 is an inherent property of the 2D intermetallic fragment. Here, the exfoliation of Bi14Rh3I9 was performed using two different chemical approaches: (a) through a reaction with n‐butyllithium and poly(vinylpyrrolidone), (b) through a reaction with betaine in dimethylformamide at 55 °C. The former yielded few‐layer sheets of the new compound Bi12Rh3I, while the latter led to crystalline sheets of Bi14Rh3I9 with a thickness down to 5 nm and edge‐lengths up to several ten microns. X‐ray diffraction and electron microscopy proved that the structure of Bi14Rh3I9 remained intact. Thus, it was assumed that the particles are still TIs. Dispersions of these flakes now allow for next steps towards the envisioned applications in nanoelectronics, such as the study of quantum coherence in deposited films, the combination with superconducting particles or films for the generation of Majorana fermions, or studies on their behavior under the influence of magnetic or electric fields or in contact with various materials occurring in devices. The method presented generally allows to exfoliate layers with high specific charges and thus the use of layered starting materials beyond van der Waals crystals.
Effect of the cooling temperature of a PET sheet on the crystallinity and mould removal time for thermoforming applications
Authors: Erchiqui Fouad , Annasabi Zouheir , Kaddami Hamid , Ben Hamou Karima , Ngoma Guyh‐Dituba
Published: October 2020

In thermoforming process, the mechanical and thermal properties induced in the moulded product depend, on one hand, on the type of polymer material, and, on the other, on the two following processing conditions: (a) the optical and the thermal properties of the infrared ovens, and (b) the temperature and mechanical properties of the mould. In addition, for semi‐crystalline polymers, the quality of product also depends on the crystallization processes. In this paper, the effect of the cooling temperature on a semi‐crystalline polymers sheet, heated beforehand by infrared radiation, on crystallinity is numerically analyzed. For this, the energy equation is coupled to the kinetics of the polymer. For this purpose, the heat equation is expressed in terms of enthalpy, and its numerical resolution is carried out using the 3D finite element method. An example of a polyethylene terephthalate (PET) sheet is presented.
Compound lower limb vibration training rehabilitation robot
Authors: Yin Qiang , Hu Ao , Li Qian , Wei Xin , Yang Hongjun , Wang Beihai , Zhang Guoquan
Published: October 2020

This paper uses a bionic lower limb rehabilitation mechanism combined with a running frame structure to simulate human gait movement for lower limb rehabilitation training. The vibration excited by the vertical vibration module causes the muscle to oscillate, and the mechanical vibration excites the neuromuscular system to obtain corresponding rehabilitation functions. The robot system is modeled in three dimensions, and the static analysis and modal analysis of the running frame are carried out. The mechanism and application of vertical vibration in the key technology are clarified, and the vibration element in the vertical vibration device is analyzed. The vibration theory is deduced, and the vibration displacement figure is drawn using simulation software. The related cooperative vibration spring has also been analyzed with single‐degree‐of‐freedom damping vibration, and the spring's center of mass movement, momentum, and position changes over time are illustrated. The design of the robot system solves the current situation of single movement of the lower limb rehabilitation robot and unsatisfactory rehabilitation effect, laying a foundation for the practical application of the subsequent lower limb rehabilitation robot system.
Enhanced Photochromism of Diarylethene Induced by Excitation of Localized Surface Plasmon Resonance on Regular Arrays of Gold Nanoparticles
Authors: Yasukuni Ryohei , Félidj Nordin , Boubekeur‐Lecaque Leïla , Lau‐Truong Stéphanie , Aubard Jean
Published: October 2020

Localized surface plasmon resonance (LSPR) excitation on the photochromic reaction of a diarylethene derivative (DE) was studied by surface enhanced Raman scattering (SERS). UV and visible light irradiations transform reversibly DE between open‐form (OF) and closed‐form (CF) isomers, respectively. A mixture of PMMA and DE (either OF or CF isomer) was spin‐coated onto gold nanorods (GNRs) arrays, designed by electron beam lithography, with two localized surface plasmon resonances (LSPR) at distinct wavelengths, due to their anisotropy. The photochromic reaction rates from CF to OF isomers, under LSPR excitation, were monitored from SERS spectral changes under different polarizations, on the same GNR substrate to compare the effect of LSPR field strength. It appears that the photoisomerization rate was faster when LSPR was excited with the polarization parallel to the GNR long axis. The present results highlight a potential genuine mechanism, from near field LSPR excitation, involved in the photochromic enhancement of diarylethene photochromes.
Preparation Process and Growth Mechanism Analysis of Phenylacetyl‐7‐Aminodeacetoxycephalosporanic Acid Crystals with Controllable Morphology
Authors: Han Kang , Liu Baoshu , Zhang Zhefan , Li Zhengjie , Sun Hua
Published: October 2020

A recrystallization process for phenylacetyl‐7‐aminodeacetoxycephalosporanic acid (phenylacetyl‐7‐ADCA) is used to obtain the monoclinic and tetragonal crystal forms. The purity of the process product is 99.7%, which is much higher than the 97.1% of the raw material, while the median (D50) particle size is larger (144 µm) and the diameter span (DS) is reduced from 10.478 (raw material) to 2.070 (new process product). The results show that in water–ethanol systems when the mole fraction of water is less than 0.5, the products obtained are long rod‐shaped, while when the mole fraction of water is greater than 0.5, lamellar crystal products are obtained. The growth mechanism of phenylacetyl‐7‐ADCA with different habits is analyzed by Materials Studio molecular simulation software. The results show that a large number of oxygen and nitrogen atoms at both ends of the crystal are exposed to the crystal surfaces during the cooling recrystallization process and it is easy to form hydrogen bonds with free phenylacetyl‐7‐ADCA. Therefore, the crystal surfaces at both ends grow fastest and tend to disappear eventually. This work may provide a preparation process and simulation method for phenylacetyl‐7‐ADCA crystals, which would help improve the quality of cephalosporins.
p‐CuInS2/n‐Polymer Semiconductor Heterojunction for Photoelectrochemical Hydrogen Evolution
Authors: Chae Sang Youn , Lee Myeongjae , Je Kim Min , Cho Jeong Ho , Kim BongSoo , Joo Oh‐Shim
Published: October 2020

An inorganic p‐type CuInS2 semiconductor was combined with the semiconducting polymer of PNDI3OT‐Se1 and PNDI3OT‐Se2 with different HOMO/LUMO levels for photoelectrochemical hydrogen production. Charge transfer behaviors at polymer/CuInS2 junctions were investigated by electrochemical impedance spectroscopy. The heterojunction of p‐CuInS2 and n‐type polymer (both PNDI3OT‐Se1 and Se2) successfully made p‐n junctions and showed improved charge transfer. However, we found that higher HOMO levels of polymer than valence band maximum (VBM) of CuInS2 spurred charge recombination at interfaces. As a result, CuInS2/PNDI3OT‐Se1/TiO2/Pt, which has suitable energy levels matched between PNDI3OT‐Se1 and CuInS2, shows photocurrent (−15.67 mA cm−2) improved concretely when compared to a CuInS2/TiO2/Pt photoelectrode (−7.11 mA cm−2) at 0.0 V vs. RHE applied potential. Additionally, the photoelectrochemical stability of CuInS2/PNDI3OT‐Se1/TiO2/Pt photoelectrode was also investigated.
Selective Conversion of CO2 into para‐Xylene over a ZnCr2O4‐ZSM‐5 Catalyst
Authors: Gao Weizhe , Guo Lisheng , Cui Yu , Yang Guohui , He Yingluo , Zeng Chunyang , Taguchi Akira , Abe Takayuki , Ma Qingxiang , Yoneyama Yoshiharu , Tsubaki Noritatsu
Published: October 2020

An oxide‐zeolite (ZnCr2O4‐ZSM‐5) catalyst for directly converting CO2 to aromatics was designed and developed. It showed high PX/X (the C‐mol ratio of p‐xylene to all xylene) and PX/aromatics (the C‐mol ratio of p‐xylene to aromatics) ratios, which reached 97.3 and 63.9 %, respectively.
Biobased Aldehydes from Fatty Epoxides through Thermal Cleavage of β‐Hydroxy Hydroperoxides**
Authors: De Dios Miguel Thomas , Duc Vu Nam , Lemaire Marc , Duguet Nicolas
Published: October 2020

The ring‐opening of epoxidized methyl oleate by aqueous H2O2 has been studied using tungsten and molybdenum catalysts to form the corresponding fatty β‐hydroxy hydroperoxides. It was found that tungstic acid and phosphotungstic acid gave the highest selectivities (92–93 %) towards the formation of the desired products, thus limiting the formation of the corresponding fatty 1,2‐diols. The optimized conditions were applied to a range of fatty epoxides to give the corresponding fatty β‐hydroxy hydroperoxides with 30–80 % isolated yields (8 examples). These species were fully characterized by 1H and 13C NMR spectroscopy and HPLC‐HRMS, and their stability was studied by differential scanning calorimetry. The thermal cleavage of the β‐hydroxy hydroperoxide derived from methyl oleate was studied both in batch and flow conditions. It was found that the thermal cleavage in flow conditions gave the highest selectivity towards the formation of aldehydes with limited amounts of byproducts. The aldehydes were both formed with 68 % GC yield, and nonanal and methyl 9‐oxononanoate were isolated with 57 and 55 % yield, respectively. Advantageously, the overall process does not require large excess of H2O2 and only generates water as a byproduct.
Projected climate change threatens significant range contraction of Cochemiea halei (Cactaceae), an island endemic, serpentine‐adapted plant species at risk of extinction
Authors: Breslin Peter B. , Wojciechowski Martin F. , Albuquerque Fabio
Published: October 2020

Aim

Threats faced by narrowly distributed endemic plant species in the face of the Earth's sixth mass extinction and climate change exposure are especially severe for taxa on islands. We investigated the current and projected distribution and range changes of Cochemiea halei, an endemic island cactus. This taxon is of conservation concern, currently listed as vulnerable on the International Union for the Conservation of Nature Red List and as a species of special concern under Mexican federal law. The goals of this study are to (a) identify the correlations between climate variables and current suitable habitat for C. halei; (b) determine whether the species is a serpentine endemic or has a facultative relationship with ultramafic soils; and (c) predict range changes of the species based on climate change scenarios.

Location

The island archipelago in Bahía Magdalena on the Pacific coast, Baja California Sur, Mexico.

Methods

We used temperature and precipitation variables at 30‐arc second resolution and soil type, employing multiple species distribution modeling methods, to identify important climate and soil conditions driving current habitat suitability. The best model of current suitability is used to predict possible effects of four climate change scenarios based on best‐case to worst‐case representative concentration pathways, with projected climate data from two general circulation models, over two time periods.

Main conclusions

The occurrence of the species is found to be strongly correlated with ultramafic soils. The most important climate predictor for habitat suitability is annual temperature range. The species is predicted to undergo range contractions from 21% to 53%, depending on the severity and duration of exposure to climate change. The broader implications for a wide range of narrowly adapted, threatened, and endemic plant species indicate an urgent need for threat assessment based on habitat suitability and climate change modeling.
Life history shifts in an exploited African fish following invasion by a castrating parasite
Authors: Gabagambi Nestory Peter , Skorping Arne , Chacha Mwita , Jonathan Kihedu Kwendwa , Mennerat Adele
Published: October 2020

Evolutionary theory predicts that infection by a parasite that reduces future host survival or fecundity should select for increased investment in current reproduction. In this study, we use the cestode Ligula intestinalis and its intermediate fish host Engraulicypris sardella in Wissman Bay, Lake Nyasa (Tanzania), as a model system. Using data about infection of E. sardella fish hosts by L. intestinalis collected for a period of 10 years, we explored whether parasite infection affects the fecundity of the fish host E. sardella, and whether host reproductive investment has increased at the expense of somatic growth. We found that L. intestinalis had a strong negative effect on the fecundity of its intermediate fish host. For the noninfected fish, we observed an increase in relative gonadal weight at maturity over the study period, while size at maturity decreased. These findings suggest that the life history of E. sardella has been shifting toward earlier reproduction. Further studies are warranted to assess whether these changes reflect plastic or evolutionary responses. We also discuss the interaction between parasite and fishery‐mediated selection as a possible explanation for the decline of E. sardella stock in the lake.
How the ecology and evolution of the COVID‐19 pandemic changed learning
Authors: Lashley Marcus A. , Acevedo Miguel , Cotner Sehoya , Lortie Christopher J.
Published: October 2020

The coronavirus disease 2019 (COVID‐19) pandemic introduced an abrupt change in human behavior globally. Here, we discuss unique insights the pandemic has provided into the eco‐evolutionary role of pathogens in ecosystems and present data that indicates the pandemic may have fundamentally changed our learning choices. COVID‐19 has indirectly affected many organisms and processes by changing the behavior of humans to avoid being infected. The pandemic also changed our learning behavior by affecting the relative importance of information and forcing teaching and learning into a framework that accommodates human behavioral measures to avoid disease transmission. Not only are these indirect effects on the environment occurring through a unique mechanistic pathway in ecology, the pandemic along with its effects on us provides a profound example of the role risk can play in the transmission of information between the at risk. Ultimately, these changes in our learning behavior led to this special issue “Taking learning online in Ecology and Evolution.” The special issue was a call to the community to take learning in new directions, including online and distributed experiences. The topics examined include a significant component of DIY ecology and evolution that is experiential but done individually, opportunities to use online tools and apps to be more inclusive, student‐focused strategies for teaching online, how to reinvent conferences, strategies to retain experiential learning safely, emerging forms of teaching such as citizen science, apps and podcasting, and ideas on how to accommodate ever changing constraints in the college classroom, to name a few. The collective consensus in our fields is that these times are challenging but we can continue to improve and innovate on existing developments, and more broadly and importantly, this situation may provide an opportunity to reset some of the existing practices that fail to promote an effective and inclusive learning environment.
From nuclear energy developmental state to energy transition in South Korea: The role of the political epistemic community
Authors: Lee Taedong
Published: October 2020

Why did previous Korean governments adopt nuclear energy as a baseline for electricity generation and promote the exportation of nuclear energy? Why did the current Korean government dramatically change its energy policy to energy transition and postnuclear energy in 2017? How did politicians, bureaucrats, industries, civil society organizations, and political epistemic communities interact in the nuclear energy policymaking process? This study addresses contemporary changes in Korean nuclear energy policy by applying the concepts “nuclear energy developmental state” and “political epistemic community.” This paper attempts to identify the relevant actors in state transition, interactive matrices in policymaking processes, and the mechanisms by which the energy baseline has shifted. A comprehensive analysis of the President's National Policy Priority Agenda, National Energy Basic Plans, the Basic Plan of Long‐Term Electricity Supply and Demand, meeting minutes of relevant government committees, and interview data of relevant actors facilitates understanding of the formation, evolution, and transformation of the contemporary state of nuclear energy throughout different political administrations, including the Lee (2008–2012), Park (2013–2016), and Moon administrations (2017–Present). I argue that political coalitions are integral in nuclear energy policy change in specific and general energy policy. Compared to highlighted agents such as bureaucrats, antinuclear movements, and epistemic communities, the political epistemic community—closely connecting knowledge, value, and power—plays a role in developing different types of political coalitions through nuclear energy decision‐making. During the Lee and Park administrations, a nuclear energy developmental state emerged with a strong coalition between politicians, bureaucrats, and the nuclear industry with support from the nuclear energy epistemic community. However, the Moon administration is characterized by a different coalition that includes politicians, civil society organizations, and the postnuclear energy epistemic community, which propels energy transition from nuclear energy to a decentralized renewable energy system.
Changing dynamics of the nuclear energy policy‐making process in Japan
Authors: Kikuchi Masao
Published: October 2020

To improve the effectiveness of environmental policy and governance, recent theoretical and empirical research increasingly suggests the adoption of multi‐level and more participatory policy‐making processes over traditionally centralized policy‐making processes. This article takes the Fukushima nuclear crisis of 2011 as a prime example in an attempt to assess the changing dynamics of the nuclear energy policy‐making process in Japan. To explore the changing dynamics, the paper focuses on the roles of the judicial branch and local governments in the nuclear energy policy‐making process. Nuclear energy policy in Japan has evolved along with industrial policies for economic growth. Before the Fukushima crisis, neither the judicial branch nor local governments were regarded as influential actors in nuclear energy policy‐making. The judicial branch basically supported government policy in litigation brought by civic groups. Local governments in rural areas tried to attract nuclear power plant construction because of promised subsidies from the national government and a solid tax base from construction and jobs. However, after the Fukushima crisis, both judicial branches and local governments became more influential in the nuclear energy policy‐making process. Local and high courts now actively issue injunctions against the reoperation of nuclear power plants. In gubernatorial or mayoral elections of local governments where nuclear power plants are located, candidates are politically pressured to express their stance on nuclear power plants more explicitly than in the past. Anti‐nuclear civic groups are also gradually changing the focus of their lobbying efforts to local elections.
Diazanorbornene: A Valuable Synthon towards Carbocycles and Heterocycles
Authors: Preethalayam Preethanuj , Jijy E. , Prakash Praveen , Chand Sarngadharan Sarath , Vijayan Ajesh , Radhakrishnan K. V. , John Jubi
Published: October 2020

Desymmetrization of meso compounds is well recognized as a powerful method for delivering biologically relevant molecular skeletons in a few synthetic steps. Heterobicyclic olefins are a class of meso compounds which exhibit exceptional reactivity due to their high ring strain originating from the unfavorable bond angles and eclipsing interactions. Extensive research was carried out towards the synthetic transformations of oxa‐, aza‐, and diazanorbornenes/norbornadienes for the synthesis of a wide variety of carbocycles and heterocycles in a single step, most importantly in a stereo‐ and chemo‐selective manner. This review summarizes the relevant aspects of diazanorbornene reactivity which will inspire the synthetic community for exploiting these highly strained bicyclic systems for the creation of extensive libraries of novel structurally and biologically interesting molecules. The review is divided into several sections based on the type of reactions that diazanorbornenes are subjected to.
Microfluidic Setup for Simultaneous Separation and Electrochemical Determination of Hg2+ and Ag+ Ions in Water
Authors: Di Masi Sabrina , Laschi Serena , Pennetta Antonio , Faraoni Paola , Ranaldi Francesco , De Benedetto Giuseppe Egidio , Malitesta Cosimino
Published: October 2020

Here is presented a setup made of a combination of an injection valve, a hand‐made chromatographic microcolumn and an electrochemical detector for the simultaneous separation of Hg2+ and Ag+ ions in water. The microcolumns were packed with exchanger resin and used for the separation of Hg2+ and Ag+ ions, whereas a screen‐printed carbon electrode (SPCE) was the amperometric detector. The performances of the SPCE towards ions were firstly studied in a FIA setup. The efficiency of ion separation was then evaluated. The reproducibility, stability, and the regeneration of the obtained microcolumns were also studied and discussed.
The Effects of Solvent on Doctor‐Bladed Perovskite Light Absorber under Ambient Process Condition for Multiple‐Cation Mixed Halide Perovskites
Authors: Huang Kuo-Wei , Li Ming-Hsien , Wu Shih-Hsiung , Chiu Pei-Ting , Chen Jen-An , Chen Yu-Hung , Lin Chen-Fu , Tung Yung-Liang , Chen Peter
Published: October 2020

A doctor‐blading process for the fabrication of triple‐cation halide‐perovskite thin films using eco‐friendly solvents under ambient conditions is demonstrated. An eco‐friendly perovskite precursor composed of γ‐butyrolactone (GBL)/dimethylsulfoxide (DMSO)/isopropanol (IPA) mixture is used. The coordination between PbI2 and DMSO effectively suppresses the perovskite crystal grow rate which results in a dense and uniform film. However, the intermediate DMSO–PbI2 phase residual has a negative impact on the perovskite film quality. The amount of residues, the trap‐state defect density, the perovskite film uniformity, and the device performance can be considerably affected by adding IPA in the precursor due to its capability to facilitate DMSO evaporation. Heating post‐treatment on the top side of the film homogenizes the evaporation rate of the air–liquid surface which leads to a larger grain size and unbroken film. The device using perovskite solution with GBL/DMSO/IPA mixture as solvent achieves a decent power conversion efficiency (PCE) of 12.3% with a Voc of 1.01 V and a Jsc of 19.3 mA cm−2. The bare device retains 76.5% of its original PCE after 25 days under ambient environment at 35 °C, with 35–40% relative humidity. A large‐size device with an active area of 2.4 cm2 delivers a PCE of 8.52%.
lncRNA HOTAIR knockdown suppresses gastric cancer cell biological activities
Authors: Chao Pan , Yongheng Feng , Jin Zhou , Yu Zhu , Shiyong Yang , Kunxing Yang , Yong Ma
Published: October 2020

The aim of this study was to characterize the involvement of long noncoding RNA HOTAIR in gastric cancer development. Measurement of HOTAIR and miRNA‐206 expression by in situ hybridization (ISH) and analyzed for the correlation between HOTAIR and miRNA‐206 in gastric cancer tissues. To evaluate the effects of HOTAIR in gastric cancer, MTT assay, flow cytometry, transwell, and wound healing assays were applied. To explain the mechanism behind HOTAIR's involvement, the expression of proteins related to it was also measured by Western blotting. Finally, correlations among related factors were determined by a luciferase target experiment. HOTAIR expression significantly increased, and miRNA‐206 expression significantly decreased in cancer tissues (p < .01 and p < .001, respectively); HOTAIR knockdown suppressed cell viability, increased cell apoptosis by maintaining cells in the G1 phase, and inhibited cell invasion and migration by regulating miRNA‐206 expression (p < .01 or p < .001). Meanwhile, with HOTAIR knockdown, CCND1 and CCND2 protein expressions were significantly suppressed, whereas miRNA‐206 expression increased (p < .01 or p < .001). HOTAIR was shown to target miRNA‐206 and miRNA‐206 targeted CCND1 and CCND2. HOTAIR knockdown had antitumor effects by suppressing CCND1 and CCND2 expression by stimulating miRNA‐206 in gastric cancer in vitro study.
Resisting ableism in deliberately developmental organizations: A discursive analysis of the identity work of employees with disabilities
Authors: Kwon Chang‐kyu
Published: October 2020

People with disabilities, an understudied population in human resource development, are often constructed as deficient and unproductive in the workplace. Such a phenomenon can largely be attributed to ableism, which is intensified by the widespread organizational emphasis on productivity. With the recognition of people with disabilities as political agents, this study examined the discursive practices of employees with disabilities in Deliberately Developmental Organizations (DDOs). DDOs as a research site were purposefully selected given their commitment to employees' continuous learning, growth, and development distinct from productivity as the main organizing principle. The critical discourse analysis of seven employees with disabilities in DDOs revealed two ways in which the participants countered the negative stereotypes associated with them: (a) the participants resisted ableism by openly communicating the scope of their ability, and (b) the participants resisted ableism by stepping outside the category of people with disabilities. These two radical ways in which the participants challenged ableism by drawing upon the empowering discursive resources in DDOs did not have ableism's reproducing effects and therefore illuminates the potential of continuing to research DDOs as a promising alternative organizational space for inclusion. This study expands our knowledge of disability identity in the workplace by highlighting that a DDO culture provides a unique context under which the distinct identity work of employees with disabilities can be observed and theorized.