bluuebunny/crossref_metadata_2025 huggingface dataset:
ATP signaling in the integrative neural center of Aplysia californica
Authors: Györi János , Kohn Andrea B. , Romanova Daria Y. , Moroz Leonid L.
Published: March 2021

ATP and its ionotropic P2X receptors are components of the most ancient signaling system. However, little is known about the distribution and function of purinergic transmission in invertebrates. Here, we cloned, expressed, and pharmacologically characterized the P2X receptors in the sea slug Aplysia californica—a prominent neuroscience model. AcP2X receptors were successfully expressed in Xenopus oocytes and displayed activation by ATP with two-phased kinetics and Na+-dependence. Pharmacologically, they were different from other P2X receptors. The ATP analog, Bz-ATP, was a less effective agonist than ATP, and PPADS was a more potent inhibitor of the AcP2X receptors than the suramin. AcP2X were uniquely expressed within the cerebral F-cluster, the multifunctional integrative neurosecretory center. AcP2X receptors were also detected in the chemosensory structures and the early cleavage stages. Therefore, in molluscs, rapid ATP-dependent signaling can be implicated both in development and diverse homeostatic functions. Furthermore, this study illuminates novel cellular and systemic features of P2X-type ligand-gated ion channels for deciphering the evolution of neurotransmitters.
A selective small-molecule inhibitor of c-Met suppresses keloid fibroblast growth in vitro and in a mouse model
Authors: Choi Min-Ha , Kim Jinhyun , Ha Jeong Hyun , Park Ji-Ung
Published: March 2021

Keloids, tumor-like lesions that result from excessive scar formation, have no definitive treatment modality. Activation of c-mesenchymal-epithelial transition factor (c-Met) promotes cell proliferation and survival. Selective c-Met inhibitors, such as PHA-665752, may attenuate the activity of keloid fibroblasts and reduce keloid formation. Here, we aimed to evaluate the effect of PHA-665752, a second-generation selective small-molecule inhibitor of c-Met, on human keloid fibroblasts in vitro and in a mouse model. We performed in vitro cytotoxicity assays, scratch tests, western blotting, and immunofluorescence on human keloid fibroblasts. We also injected human fibroblasts into severe combined immunodeficient mice and measured the degree of nodule formation and skin histologic characteristics. We found that keloid fibroblast migration was inhibited by PHA-665752. Inhibitor treatment was also associated with lower expression of members of the hepatocyte growth factor/c-Met pathway, and lower fibroblast activity and collagen synthesis. In the in vivo experiments, PHA-665752—treated mice had lower nodule volumes and weights, accompanied by less inflammatory cell infiltration and collagen deposition, than those in control mice. These findings showed that although an in vivo model may not accurately represent the pathophysiology of human keloid development, PHA-665752 suppressed keloid fibroblast activity by inhibiting the c-Met—related tyrosine kinase pathway.
Effect of high proportion concentrate dietary on Yak jejunal structure, physiological function and protein composition during cold season
Authors: Jia Jianlei , Liang Chunnian , Wu Xiaoyun , Xiong Lin , Bao Pengjia , Chen Qian , Yan Ping
Published: March 2021

The current study aimed to investigate the damage of long-term high concentrate diet feeding pattern on Yak jejunal structure, physiological function and protein composition during cold season. Twelve Datong male Yak (Bos grunniens) with the same age from cold season were randomly selected and slaughtered to determine Yak jejunal digestive enzyme activity, morphology and protein composition on different feeding patterns in Tibetan Plateau. The results showed that Yak jejunum digestive enzyme activity and morphology of grazing reared group were better than those in the intensively reared group. A total of 96 differentially expressed proteins were identified by label-free Mass Spectrometry (MS), which could be concluded to two predominant themes: protein structure and inflammatory response. Nine differentially expressed proteins were correlated in Yak jejunum damage in different feeding patterns. According to this research, we found that feeding pattern resulted the differences in Yak jejunum physiological function, morphology and protein composition. This fact was confirmed long-term high dietary concentrate feeding could damage the jejunum epithelial morphology and function.
High S100A2 expression in keratinocytes in patients with drug eruption
Authors: Yoshioka Manabu , Sawada Yu , Saito-Sasaki Natsuko , Yoshioka Haruna , Hama Kayo , Omoto Daisuke , Ohmori Shun , Okada Etsuko , Nakamura Motonobu
Published: March 2021

Telaprevir used as a protease inhibitor against hepatitis C virus is frequently associated with cutaneous adverse reactions. To explore a histological biomarker of cutaneous adverse events induced by telaprevir, we systematically searched for genes that were dysregulated by telaprevir in normal human epidermal keratinocytes (NHEKs). Microarray analysis and real-time polymerase chain reaction (PCR) revealed the significant increase in the expression of S100 calcium-binding protein A2 (S100A2) gene following treatment of NHEKs with telaprevir. Immunohistochemical analysis demonstrated that the expression of S100A2 was dominant in the spinous layer of the epidermis in patients with telaprevir-mediated severe-type drug eruptions and limited to the basal layer of the epidermis in healthy subjects. Furthermore, S100A2 expression increased after treatment with trichloroethylene and other medications, and the degree of S100A2 expression correlated with the severity of cutaneous adverse events. S100A2 expression also significantly increased in the skin of patients with atopic dermatitis and psoriasis. Taken together, S100A2 is highly expressed in the epidermis under inflammatory conditions and drug eruptions and may serve as a marker for keratinocyte damage in response to any inflammatory or toxic condition.
Tert-butylhydroquinone attenuates doxorubicin-induced dysregulation of testicular cytoprotective and steroidogenic genes, and improves spermatogenesis in rats
Authors: Ujah Godwin Adakole , Nna Victor Udo , Suleiman Joseph Bagi , Eleazu Chinedum , Nwokocha Chukwuemeka , Rebene Joy Assima , Imowo Michael Umana , Obi Emmanuel Ochui , Amachree Charlette , Udechukwu Evarest Chigozie , Mohamed Mahaneem
Published: March 2021

Doxorubicin (DOX) is a broad-spectrum chemotherapeutic drug used in the treatment of cancers. It acts by generating reactive oxygen species in target cells. The actions are, however, not limited to cancerous cells as it attacks healthy cells, killing them. This study investigated the benefits of the antioxidant, tert-butylhydroquinone (tBHQ), on testicular toxicity following DOX therapy. Twenty-four adult male albino rats were assigned randomly into four groups (n = 6), namely: normal control (NC), tBHQ, DOX and tBHQ + DOX groups. tBHQ (50 mg/kg body weight in 1% DMSO) was administered orally for 14 consecutive days, while a single DOX dose (7 mg/kg body weight) was administered intraperitoneally on Day 8. DOX decreased sperm count, motility and viability, and decreased the levels of steroidogenesis-related proteins, and reproductive hormones. Furthermore, DOX decreased the expression of antioxidant cytoprotective genes, and decreased the protein level of proliferating cell nuclear antigen in the testis. Conversely, DOX increased the expression of pro-inflammatory and pro-apoptotic genes in the testis. These negative effects were ameliorated following the intervention with tBHQ. Our results suggest that tBHQ protects the testis and preserves both steroidogenesis and spermatogenesis in DOX-treated rats through the suppression of oxidative stress, inflammation and apoptosis.
Telomere lengths correlate with fitness but assortative mating by telomeres confers no benefit to fledgling recruitment
Authors: Young Rebecca C. , Kitaysky Alexander S. , Drummond Hugh M.
Published: March 2021

Assortative mating by telomere lengths has been observed in several bird species, and in some cases may increase fitness of individuals. Here we examined the relationship between telomere lengths of Blue-footed Booby (Sula nebouxii) mates, long-lived colonial seabirds with high annual divorce rates. We tested the hypothesis that interactions between maternal and paternal telomere lengths affect offspring and parental survival. We found that relative telomere lengths (RTL) were strongly positively correlated between members of a breeding pair. In addition, RTL of both parents interacted to predict fledgling recruitment, although fledglings with two very long-RTL parents performed only averagely. Telomere lengths also predicted adult survival: birds with long telomeres were more likely to survive, but birds whose mate had long telomeres were less likely to survive. Thus, having long telomeres benefits survival, while choosing a mate with long telomeres benefits reproductive output while penalizing survival. These patterns demonstrate that while a breeder's RTL predicts offspring quality, assortative mating by RTL does not enhance fitness, and a trade-off between different components of fitness may govern patterns of assortative mating by telomere length. They also illustrate how testing the adaptive value of only one parent’s telomere length on either survival or reproductive success alone may provide equivocal results.
Physiological changes and transcriptome profiling in Saccharum spontaneum L. leaf under water stress and re-watering conditions
Authors: Li Changning , Wang Zhen , Nong Qian , Lin Li , Xie Jinlan , Mo Zhanghong , Huang Xing , Song Xiupeng , Malviya Mukesh Kumar , Solanki Manoj Kumar , Li Yangrui
Published: March 2021

As the polyploidy progenitor of modern sugarcane, Saccharum spontaneum is considered to be a valuable resistance source to various biotic and abiotic stresses. However, little has been reported on the mechanism of drought tolerance in S. spontaneum. Herein, the physiological changes of S. spontaneum GXS87-16 at three water-deficit levels (mild, moderate, and severe) and after re-watering during the elongation stage were investigated. RNA sequencing was utilized for global transcriptome profiling of GXS87-16 under severe drought and re-watered conditions. There were significant alterations in the physiological parameters of GXS87-16 in response to drought stress and then recovered differently after re-watering. A total of 1569 differentially expressed genes (DEGs) associated with water stress and re-watering were identified. Notably, the majority of the DEGs were induced by stress. GO functional annotations and KEGG pathway analysis assigned the DEGs to 47 GO categories and 93 pathway categories. The pathway categories were involved in various processes, such as RNA transport, mRNA surveillance, plant hormone signal transduction, and plant-pathogen interaction. The reliability of the RNA-seq results was confirmed by qRT-PCR. This study shed light on the regulatory processes of drought tolerance in S. spontaneum and identifies useful genes for genetic improvement of drought tolerance in sugarcane.
Sediment supply dampens the erosive effects of sea-level rise on reef islands
Authors: Tuck Megan E. , Ford Murray R. , Kench Paul S. , Masselink Gerd
Published: March 2021

Large uncertainty surrounds the future physical stability of low-lying coral reef islands due to a limited understanding of the geomorphic response of islands to changing environmental conditions. Physical and numerical modelling efforts have improved understanding of the modes and styles of island change in response to increasing wave and water level conditions. However, the impact of sediment supply on island morphodynamics has not been addressed and remains poorly understood. Here we present evidence from the first physical modelling experiments to explore the effect of storm-derived sediment supply on the geomorphic response of islands to changes in sea level and energetic wave conditions. Results demonstrate that a sediment supply has a substantial influence on island adjustments in response to sea-level rise, promoting the increase of the elevation of the island while dampening island migration and subaerial volume reduction. The implications of sediment supply are significant as it improves the potential of islands to offset the impacts of future flood events, increasing the future physical persistence of reef islands. Results emphasize the urgent need to incorporate the physical response of islands to both physical and ecological processes in future flood risk models.
Comparative analysis of contributions of wet deposition and photodegradation to the removal of atmospheric BaP by MFDCCA
Authors: Liu Chunqiong , Guo Yuanyuan , Shi Kai , Zhang Jiao , Wu Bo , Du Juan
Published: March 2021

Benzo [a] pyrene (BaP) in the atmosphere possess great carcinogenic potential to human health, and the understanding of its scavenging mechanisms has attracted considerable attention. In this work, a new quantitative method is proposed to make a comparative analysis of the long-term contributions of wet deposition and photodegradation to BaP removal based on multi-fractal detrended cross-correlation analysis (MFDCCA). According to the precipitation and global solar radiation (GSR) observations from 1998 to 2016 for two urban sites (Central/Western District and TsuenWan) in Hong Kong, the wet deposition and photodegradation of BaP are analyzed. Using MFDCCA method, long-term cross-correlation between precipitation/GSR and BaP are investigated. Moreover, the differences of multifractal features in cross-correlations of precipitation-BaP and GSR-BaP system are analyzed. Strong long-term persistence is observed in the cross-correlations for precipitation-BaP system in a one-year cycle; while cross-correlations between GSR and BaP show weak persistence over the whole timescale. Based on the meteorology in Hong Kong, this difference has been discussed. Then, contributions of wet deposition and photodegradation to atmospheric BaP removal are quantified based on MFDCCA method, which are further compared between summer and winter. The comparative analysis suggests that wet deposition plays a more significant role in the removal of atmospheric BaP. Specifically, in summer, the contributions of wet deposition are twice as much as that of photodegradation for both two sites; while in winter, the contribution of photodegradation is a little higher than that of wet deposition to BaP removal. Meanwhile, for wet deposition, the contributions in summer are about ten times greater than that in winter; while for photodegradation, the difference in contributions between summer and winter are relatively smaller. Furthermore, based on sliding window technique, the temporal evolutions in the contributions of wet deposition/photodegradation to BaP removal have been presented for both two sites. On this basis, it is discovered that the comprehensive contributions of wet deposition and photodegradation peak in June, and reach their lowest levels in December for both two sites. Quantifying the contribution of meteorological factors to the removal of atmospheric BaP is help for understanding its geochemical cycle.
Author Correction: Organophosphorus diisopropylfluorophosphate (DFP) intoxication in zebrafish larvae causes behavioral defects, neuronal hyperexcitation and neuronal death
Authors: Brenet Alexandre , Somkhit Julie , Hassan-Abdi Rahma , Yanicostas Constantin , Romain Christiane , Bar Olivier , Igert Alexandre , Saurat Dominique , Taudon Nicolas , Dal-Bo Gregory , Nachon Florian , Dupuis Nina , Soussi-Yanicostas Nadia
Published: March 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Location of carbon–carbon double bonds in unsaturated lipids using microdroplet mass spectrometry
Authors: Luo Kai , Chen Hao , Zare Richard N.
Published: March 2021

Microdroplet mass spectrometry for the location of carbon–carbon double bonds in unsaturated fatty acids and lipids via ROS generation at the air–water interface.
Determination of the dispersion forces in the gas phase structures of ionic liquids using exclusively thermodynamic methods
Authors: Zaitsau Dzmitry H. , Ludwig Ralf , Verevkin Sergey P.
Published: March 2021

Dispersion interactions in the gas phase ion pairs of ionic liquids determined using purely thermodynamic methods.
Homogeneous and heterogeneous catalysts for hydrogenation of CO2 to methanol under mild conditions
Authors: Bai Shao-Tao , De Smet Gilles , Liao Yuhe , Sun Ruiyan , Zhou Cheng , Beller Matthias , Maes Bert U. W. , Sels Bert F.
Published: March 2021

This review summarizes the concepts, mechanisms, drawbacks and challenges of the state-of-the-art catalysis for CO2 to MeOH under mild conditions. Thoughtful guidelines and principles for future research are presented and discussed.
Microcalorimetric adsorption and infrared spectroscopic studies of supported Pd, Ru and Pd–Ru catalysts for the hydrogenation of aromatic rings with carboxyl groups
Authors: Zhao Shiling , Cai Jingxuan , Hou Qiumei , Zhao Danyang , Shen Jianyi
Published: March 2021

Pd–Ru/SiO2 showed special surface chemical properties that were totally different from those of Pd/SiO2 and Ru/SiO2 and exhibited high activity and selectivity for the hydrogenation of benzoic acid to cyclohexanecarboxylic acid.
Halogen bonding in uranyl and neptunyl trichloroacetates with alkali metals and improved crystal chemical formulae for coordination compounds
Authors: Savchenkov Anton V. , Uhanov Andrei S. , Grigoriev Mikhail S. , Fedoseev Aleksandr M. , Pushkin Denis V. , Serezhkina Larisa B. , Serezhkin Viktor N.
Published: March 2021

A new donor–acceptor halogen bond synthon is recognized and the notation of ligand coordination modes and crystal chemical formulae is improved.
An ultra-sensitive selective fluorescent sensor based on a 3D zinc-tetracarboxylic framework for the detection and enrichment of trace Cu2+ in aqueous media
Authors: Han Mei-Rong , Dong Wen-Xia , Feng Si-Si , Lu Li-Ping , Li Zhong-Ping
Published: March 2021

A novel fluorescent zinc-organic framework possessing free Lewis base sites for highly selective and sensitive Cu2+ sensing and enrichment in aqueous solution.
Revealing the antiaging effects of cereal- and food oil-derived active substances by a Caenorhabditis elegans model
Authors: Xu Danling , Lin Qinlu , Wu Wei , Wu Yixin , Liang Ying
Published: March 2021

Active substances extracted from cereal and oil products, indispensable parts of a human’s daily diet, remarkably affect the aging process. Caenorhabditis elegans is becoming a powerful biological system for related functional and mechanism studies.
Topological investigation of the reaction mechanism of glycerol carbonate decomposition by bond evolution theory
Authors: Adjieufack Abel Idrice , Liégeois Vincent , Mbouombouo Ndassa Ibrahim , Champagne Benoît
Published: March 2021

ELFs of glycerol carbonate and of its kinetic and thermodynamic decomposition product, 3-hydroxypropanal (+CO2).
The microstructures and mechanical properties of nanocrystalline Li2SiO3: molecular dynamics simulations
Authors: Shen Yan Hong , Yu You , Kong Xiang Gang , Deng Jiang , Tian Xiao Feng , Liang Yan Jun
Published: March 2021

The microstructures and mechanical properties of nanocrystalline Li2SiO3 have been investigated via molecular dynamics calculations.
Tuning polyoxometalate composites with carbonaceous materials towards oxygen bifunctional activity
Authors: Nagaiah Tharamani C. , Gupta Divyani , Adhikary Subhasis Das , Kafle Alankar , Mandal Debaprasad
Published: March 2021

Polyoxometalate composites with carbon nanotubes (PVIM–CoPOM/NCNT) towards oxygen bifunctional activity.
Enhancing and tuning broadband near-infrared (NIR) photoluminescence properties in Cr3+-doped Ca2YHf2Al3O12 garnet phosphors via Ce3+/Yb3+-codoping for LED applications
Authors: Zhang Qianqian , Li Guogang , Dang Peipei , Liu Dongjie , Huang Dayu , Lian Hongzhou , Lin Jun
Published: March 2021

NIR emission from 650 nm to 1100 nm in a novel Ca2YHf2Al3O12:Cr3+,Yb3+ garnet phosphor with good thermal stability and high internal quantum efficiency is designed for NIR pc-LEDs.
A novel AIE molecule as a hole transport layer enables efficient and stable perovskite solar cells
Authors: Huang Bin , Cheng Yujun , Lei Hui , Hu Lin , Li Zaifang , Huang Xuexiang , Chen Lie , Chen Yiwang
Published: March 2021

The novel AIE characteristic of the HTL improves the efficiency and stability of the PeSCs.
The link to polysulfides and their applications
Authors: Park Kun Woo , Leitao Erin M.
Published: March 2021

Inverse vulcanisation converts sulfur into polysulfide via ring opening polymerisation followed by stabilisation using a variety of different crosslinkers. The linkers dictate the properties of the materials and lead to diverse applications.
Cobalt(iii)-catalyzed redox-neutral [4+2]-annulation of N-chlorobenzamides/acrylamides with alkylidenecyclopropanes at room temperature
Authors: Ramesh Balu , Jeganmohan Masilamani
Published: March 2021

An efficient synthesis of substituted 3,4-dihydroisoquinolinones through [4+2]-annulation of N-chlorobenzamides/acrylamides with alkylidenecyclopropanes using a less expensive and air stable Co(iii) catalyst is demonstrated.
One-step hydrothermal synthesis of chiral carbon dots with high asymmetric catalytic activity for an enantioselective direct aldol reaction
Authors: Liu Shuang , He Yu , Liu Yu , Wang Shuaibin , Jian Yajun , Li Baoxin , Xu Chunli
Published: March 2021

Chiral carbon dots are prepared by a simple and one-step hydrothermal reaction at 180 °C for 2 h using citric acid and d-proline as precursors, which show high asymmetric catalytic activity for enantioselective direct aldol condensation.
Fast estimation of the internal conversion rate constant in photophysical applications
Authors: Valiev R. R. , Nasibullin R. T. , Cherepanov V. N. , Kurtsevich A. , Sundholm D. , Kurtén T.
Published: March 2021

An efficient method for estimating non-adiabatic coupling matrix elements (NACME) and rate constants for internal conversion (kIC) is presented.
Pauli-paramagnetic and metallic properties of high pressure polymorphs of BaRhO3 oxides containing Rh2O9 dimers
Authors: Injac Sean D. A. , Xu Yuanhui , Denis Romero Fabio , Shimakawa Yuichi
Published: March 2021

A new high pressure polymorph of BaRhO3 was prepared at 14 GPa and found to adopt the 6H perovskite structure. This polymorph and the 4H polymorph were investigated and determined to show Pauli paramagnetic, and metallic conduction properties.
A ferrocene-based pseudopeptide chiroptical switch
Authors: Opačak Saša , Babić Darko , Perić Berislav , Marinić Željko , Smrečki Vilko , Pem Barbara , Vinković Vrček Ivana , Kirin Srećko I.
Published: March 2021

A ferrocene pseudopeptide chiroptical switch sensitive to solvent exchange and acid addition with a response in the visible region of CD spectra.
Low valent lead and tin hydrides in reactions with heteroallenes
Authors: Weiß Sebastian , Widemann Max , Eichele Klaus , Schubert Hartmut , Wesemann Lars
Published: March 2021

Hydroelementation reactions of low valent tin and lead hydride with heteroallenes are presented.
A heavy-atom-free π-extended N-confused porphyrin as a photosensitizer for photodynamic therapy
Authors: Babu Balaji , Mack John , Nyokong Tebello
Published: March 2021

A heavy-atom-free π-extended N-confused porphyrin is reported that is suitable for use as a photosensitizer for photodynamic therapy in both the green region and therapeutic window.
Oxidative azidations of phenols and ketones using iodine azide after release from an ion exchange resin
Authors: Kösel Teresa , Dräger Gerald , Kirschning Andreas
Published: March 2021

Oxidative azidations of phenols and ketones are safely achieved by a polymer-bound analogue of iodoazide.
Dissolution behavior of precious metals and selective palladium leaching from spent automotive catalysts by trihalide ionic liquids
Authors: Van den Bossche Arne , Rodriguez Rodriguez Nerea , Riaño Sofía , Dehaen Wim , Binnemans Koen
Published: March 2021

Trichloride ionic liquids were used to increase the leaching selectivity of palladium from spent automotive catalyst with a ceramic support.
Metal free C-3 chalcogenation (sulfenylation and selenylation) of 4H-pyrido[1,2-a]pyrimidin-4-ones
Authors: Ghosh Prasanjit , Chhetri Gautam , Das Sajal
Published: March 2021

We have discovered an unprecedented metal-free route for the direct C-3 chalcogenation of various 4H-pyrido[1,2-a]pyrimidin-4-ones under mild conditions in good to excellent yields.
A green metal-free “one-pot” microwave assisted synthesis of 1,4-dihydrochromene triazoles
Authors: Alves Tânia M. F. , Jardim Guilherme A. M. , Ferreira Marco A. B.
Published: March 2021

A straightforward metal-free “one-pot” microwave procedure using PEG400 as the sole solvent in an eco-friendly process for the synthesis of 4-aryl-1,4-dihydrochromene-triazoles is described.
The structural changes in the signaling mechanism of bacteriophytochromes in solution revealed by a multiscale computational investigation
Authors: Macaluso Veronica , Salvadori Giacomo , Cupellini Lorenzo , Mennucci Benedetta
Published: March 2021

A combination of MD simulations and a polarizable QM/MM description of a bacteriophytochrome in solution reveals the changes in the chromophore-binding pocket and in the overall structure of the phytochrome involved in the signaling mechanism.
Gel-to-gel non-variant transition of an organogel caused by polymorphism from nanotubes to crystallites
Authors: Schwaller Duncan , Zapién-Castillo Samuel , Carvalho Alain , Combet Jérôme , Collin Dominique , Jacomine Leandro , Kékicheff Patrick , Heinrich Benoît , Lamps Jean-Philippe , Díaz-Zavala Nancy P. , Mésini Philippe J.
Published: March 2021

An organogel shows a gel-to-gel transition corresponding to the transformation of nanotubular aggregates into plain fibers, either by heating or aging. The domains of the existence of both gels are mapped in thec–Tphase diagram.
Optimized electron occupancy of solid-solution transition metals for suppressing the oxygen evolution of Li2MnO3
Authors: Song Erhong , Hu Yifan , Ma Ruguang , Li Yining , Zhao Xiaolin , Wang Jiacheng , Liu Jianjun
Published: March 2021

Li-rich layered cathodes based on Li2MnO3 have exhibited extraordinary promise to satisfy the rapidly increasing demand for high-energy density Li-ion batteries.
Template-free synthesis of polyacrylonitrile-derived porous carbon nanoballs on graphene for efficient oxygen reduction in zinc–air batteries
Authors: Begum Halima , Ahmed Mohammad Shamsuddin , Jung Seunghun
Published: March 2021

Introducing abundant active sites and improving their activity are two critical considerations for designing metal-free nitrogenous electrocatalysts for the oxygen reduction reaction (ORR) in energy conversion devices such as metal–air batteries and fuel cells.
Excitation energy transfer kinetics of trimeric, monomeric and subunit-depleted Photosystem I from Synechocystis PCC 6803
Authors: Akhtar Parveen , Biswas Avratanu , Kovács László , Nelson Nathan , Lambrev Petar H.
Published: March 2021

Photosystem I is the most efficient photosynthetic enzyme with structure and composition highly conserved among all oxygenic phototrophs. Cyanobacterial Photosystem I is typically associated into trimers for reasons that are still debated. Almost universally, Photosystem I contains a number of long-wavelength-absorbing ‘red’ chlorophylls (Chls), that have a sizeable effect on the excitation energy transfer and trapping. Here we present spectroscopic comparison of trimeric Photosystem I from Synechocystis PCC 6803 with a monomeric complex from the ΔpsaL mutant and a ‘minimal’ monomeric complex ΔFIJL, containing only subunits A, B, C, D, E, K and M. The quantum yield of photochemistry at room temperature was the same in all complexes, demonstrating the functional robustness of this photosystem. The monomeric complexes had a reduced far-red absorption and emission equivalent to the loss of 1.5–2 red Chls emitting at 710–715 nm, whereas the longest-wavelength emission at 722 nm was not affected. The picosecond fluorescence kinetics at 77 K showed spectrally and kinetically distinct red Chls in all complexes and equilibration times of up to 50 ps. We found that the red Chls are not irreversible traps at 77 K but can still transfer excitations to the reaction centre, especially in the trimeric complexes. Structure-based Förster energy transfer calculations support the assignment of the lowest-energy state to the Chl pair B37/B38 and the trimer-specific red Chl emission to Chls A32/B7 located at the monomer–monomer interface. These intermediate-energy red Chls facilitate energy migration from the lowest-energy states to the reaction centre.
Inhibition of SENP2-mediated Akt deSUMOylation promotes cardiac regeneration via activating Akt pathway
Authors: Chen Yijin , Xu Tong , Li Mengsha , Li Chuling , Ma Yusheng , Chen Guojun , Sun Yili , Zheng Hao , Wu Guangkai , Liao Wangjun , Liao Yulin , Chen Yanmei , Bin Jianping
Published: March 2021

Post-translational modification (PTM) by small ubiquitin-like modifier (SUMO) is a key regulator of cell proliferation and can be readily reversed by a family of SUMO-specific proteases (SENPs), making SUMOylation an ideal regulatory mechanism for developing novel therapeutic strategies for promoting a cardiac regenerative response. However, the role of SUMOylation in cardiac regeneration remains unknown. In the present study, we assessed whether targeting protein kinase B (Akt) SUMOylation can promote cardiac regeneration. Quantitative PCR and Western blotting results showed that small ubiquitin-like modifier-specific protease 2 (SENP2) is up-regulated during postnatal heart development. SENP2 deficiency promoted P7 and adult cardiomyocyte (CM) dedifferentiation and proliferation both in vitro and in vivo. Mice with SENP2 deficiency exhibited improved cardiac function after MI due to CM proliferation and angiogenesis. Mechanistically, the loss of SENP2 up-regulated Akt SUMOylation levels and increased Akt kinase activity, leading to a decrease in GSK3β levels and subsequently promoting CM proliferation and angiogenesis. In summary, inhibition of SENP2-mediated Akt deSUMOylation promotes CM differentiation and proliferation by activating the Akt pathway. Our results provide new insights into the role of SUMOylation in cardiac regeneration.
Global asymptotic stability of a general biased min‐consensus protocol
Authors: Mo Yuanqiu , Yu Lanlin , Yu Changbin
Published: March 2021

In this paper, a general biased min‐consensus protocol for continuous‐time multi‐agent systems is presented. In this protocol, agents considered as sources maintain static states, while the state of each non‐source agent evolves using a general min‐consensus‐like function, which takes the states of its neighbours and a biased term as inputs. The properties of the general function have been identified so that the proposed protocol can achieve global asymptotic stability. Unlike conventional consensus protocols where a network of agents reach an agreement on certain quantities of interest, agents under the general biased min‐consensus protocol will converge to different states but can generate various design results pertaining to complex combinatorial optimization problems, such as the shortest path problem and its variants.
Observer‐based output feedback H∞ control of two‐dimensional systems with periodic scheduling protocol and redundant channels
Authors: Li Dehao , Liang Jinling , Wang Fan
Published: March 2021

In this study, the observer‐based output feedback control problem is investigated for the two‐dimensional (2D) networked control system (NCS) in form of Fornasini–Marchesini second model. The communication from the controller to the actuator is carried out through a shared network medium, where only one signal gets the network access at each transmission instant. To avoid data collisions, the periodic scheduling protocol is employed to assign the network access priority to the actuator in chronological order. To improve the reliability of data transmission, redundant channels are applied to deliver the measurement observed by the sensor to the controller. The aim of the addressed problem is to design an observer‐based output feedback controller so that the considered 2D NCS satisfy a predefined performance index. Sufficient condition is given to ensure the performance of the closed‐loop system via the Lyapunov theory and stochastic analysis. Moreover, the observer‐based output feedback controller is designed to achieve the desired performance index, under which the controller parameters are determined by solving certain optimisation problems. Finally, a numerical example is given to demonstrate the feasibility of the proposed approach.
TESS unveils the optical phase curve of KELT-1b
Authors: von Essen C. , Mallonn M. , Piette A. , Cowan N. B. , Madhusudhan N. , Agol E. , Antoci V. , Poppenhaeger K. , Stassun K. G. , Khalafinejad S. , Tautvaišienė G.
Published: March 2021

We present the detection and analysis of the phase curve of KELT-1b at optical wavelengths, analyzing data taken by the Transiting Exoplanet Survey Satellite (TESS) during cycle 2 and sector 17. With a mass of ~27 MJup, KELT-1b is an example of a low-mass brown dwarf. Due to the high mass and close proximity of its companion, the host star exhibits a TESS light curve that shows clear ellipsoidal variations. We modeled the data with a six-component model: secondary eclipse, phase curve accounting for reflected light and thermal emission, Doppler beaming, ellipsoidal variations, stellar activity, and the primary transit. We determined the secondary eclipse depth in the TESS bandpass to be 304 ± 75 parts-per-million (ppm). In addition, we measured the amplitude of the phase curve to be 128 ± 27 ppm, with a corresponding eastward offset between the region of maximum brightness and the substellar point of 19.2 ± 9.6 degrees, with the latter showing good agreement with Spitzer measurements. We determined a day-side brightness temperature in the TESS bandpass of 3201 ± 147 K that is approximately 200 K higher than the values determined from the Spitzer 3.6 and 4.5 μm data. By combining TESS and Spitzer eclipse depths, we derived a day-side effective temperature of Teff = 3010 ± 78 K. Previously published eclipse depths in the near-infrared suggest a much higher brightness temperature and this discrepancy cannot be explained by spectral models combined with the current data. We attribute those large eclipse depths to unmodeled ellipsoidal variations, which would typically be manifested as a deeper secondary eclipse in observations with insufficient phase coverage. A one-dimensional self-consistent atmospheric model is able to explain the TESS and Spitzer day-side brightness temperatures with thermal emission alone and no reflected light. The difference between the TESS and Spitzer brightness temperatures can be explained via CO absorption due to a non-inverted temperature profile. The night side data fix an upper limit of ~2000 K on the internal temperature of KELT-1 b.
Pushing planets into an inner cavity by a resonant chain
Authors: Ataiee S. , Kley W.
Published: March 2021

Context. The orbital distribution of exoplanets indicates an accumulation of super-Earth sized planets close to their host stars in compact systems. When an inward disc-driven migration scenario is assumed for their formation, these planets could have been stopped and might have been parked at an inner edge of the disc, or be pushed through the inner disc cavity by a resonant chain. This topic has not been properly and extensively studied.

Aims. Using numerical simulations, we investigate the possibility that the inner planets in a resonant chain can be pushed into the disc inner cavity by outer planets.

Methods. We performed hydrodynamical and N-body simulations of planetary systems embedded in their nascent disc. The inner edge of the disc was represented in two different ways, resembling either a dead zone inner edge (DZ) or a disc inner boundary (IB). The main difference lies in the steepness of the surface density profile. The innermost planet always has a mass of 10 MEarth, with additional outer planets of equal or higher mass.

Results. A steeper profile is able to stop a chain of planets more efficiently than a shallower profile. The final configurations in our DZ models are usually tighter than in their IB counterparts, and therefore more prone to instability. We derive analytical expressions for the stopping conditions based on power equilibrium, and show that the final eccentricities result from torque equilibrium. For planets in thinner discs, we found, for the first time, clear signs for over-stable librations in the hydrodynamical simulations, leading to very compact systems. We also found that the popular N-body simulations may overestimate the number of planets in the disc inner cavity.
Optimization on kinematic characteristics and lightweight of a camellia fruit picking machine based on the Kriging surrogate model
Authors: Kang Di , Chen Ze Jun , Fan You Hua , Li Cheng , Mi Chengji , Tang Ying Hong
Published: March 2021

In order to achieve fully automated picking of camellia fruit and overcome the technical difficulties of current picking machinery such as inefficient service and manual auxiliary picking, a novel multi-links-based picking machine was proposed in this paper. The working principle and process of this device was analyzed. The mechanism kinematics equation was given, and the velocity executive body was obtained, as well as the acceleration. The acceleration at pivotal positions was tested in the camellia fruit forest, and the simulated results agreed well with the experimental ones. Then, the maximum acceleration of executive body and weight was considered as the optimization objective, and the rotating speed of crank, the radius and thickness of crank and the length and radius of link rod were regarded as the design variable. Based on the Kriging surrogate model, the relationship between variables and optimization objectives was built, and their interrelations were analyzed. Finally, the optimal solution was acquired by the non-dominated sorting genetic algorithm II, which resulted in the reduction of the maximum acceleration of executive body by 31.30%, as well as decrease of weight by 27.51%.
Experience in developing professional competences of social pedagogues in higher educational institutions of Kazakhstan
Authors: Magauova Akmaral , Makhambetova Zhamilya , Iskakova Aigul , Yessim Ulzhalgas , Narkulova Bakhtykul
Published: March 2021

In the era of integration, the key resource of the country is the training of professionals in the social sphere. Global trends require the development of competences among University students. The scientific novelty and theoretical significance of the study, which consists in studying the experience of training social pedagogues at higher education institutions in Kazakhstan, taking into account the modern competency-oriented paradigm of education, is justified. The authors revealed that the competency-based approach at Kazakhstani universities is implemented in accordance with the principles of the Bologna Declaration. The relationship between educational programs and professional standards in Kazakhstan is consistent with modern international documents, primarily the European qualification framework, expressed in the Dublin descriptors. The researchers describe educational programs for training social pedagogues, the typology of competences implemented in the system of professional training of future specialists is presented. It is proved that an important element of educational programs is their modular structure and calculation of the volume of academic load in ECTS credits. The authors, based on the identification of the nature and trends in the training of social pedagogues at Kazakhstani universities as well as the analysis of regulatory documents, identified the general and special in the process of developing the competences of social pedagogues and made a forecast about the need to focus on professional competences accepted by the world community.
Operating educational networks in Northern Ireland: the EQI shaped professional learning network
Authors: O’Hara Joe , Shevlin Patrick , Brown Martin , McNamara Gerry
Published: March 2021

This paper reports on the operation of the DCU Shaped Professional Learning Network (DCU SPLN), an initiative of the Centre for Evaluation Quality and Inspection (EQI) at Dublin City University. The DCU SPLN was initially established in Belfast, Northern Ireland as part of the Erasmus+ Project, 'Polycentric inspections of networks of schools', the focus of which was to provide an assessment of the potential of polycentric inspection as a tool for improving school effectiveness and outcomes. The cluster has now grown to 140 schools organised in regional clusters throughout Northern Ireland. The paper provides examples of the impact of the network on policy and practice in Northern Ireland. Firstly, it has a Hearts and Minds driving force that is centered on the ethical use of first-hand evidence to drive school improvement and associated action research. Secondly, it is underpinned by the existence and support from external agencies, in this case, researchers at EQI. Thirdly, the professional development provided to schools by EQI and subsequent adjustments by participants and advisors had a direct ongoing positive impact on improving the actual quality of learning in individual schools. Finally, one of the key learning points was the gradual transfer of responsibility for professional learning provision from the EQI researchers to the leaders and teachers involved in the cluster. The paper concludes with drawing some general conclusions about the role of networks in educational practice.
Dialogue between Moscow teachers and parents about the quality of preschool education
Authors: Shiyan Igor , Le-van Tatiana
Published: March 2021

Involvement of parents and teachers into decision making about evaluation criteria allows to establish partnership relations, confidence and awareness in implementation of preschool education programs. Such dialogue is necessary at the stage of transition to new norm, implementation of new national standards. In order to reveal the concepts of teachers and parents about good kindergarten, the research was carried out (anonymous survey using standard toolkit of European Quality Seal international project). The participants were 57 teachers and 284 parents from 26 Moscow schools with full-day preschool groups. The point of view of 18 experts in the field of preschool education was presented additionally. In general, the proposed criteria are important for respondents of all categories. Teachers demonstrate higher mean values in comparison with parents. Teachers and parents often have the same concepts about the value of these or those provisions: participation of parents in learning process as well as fee from parents are not important. Child-adult interaction, child’s well-being and safety are the main priorities. The experts partially agree with teachers and parents concerning the most and the least significant criteria: among the most important, together with well-being, individualization of education and free play time are highlighted. The survey results can provide an objective ground for dialogue between teachers, parents, and authorities both at the level of ECEC service and at municipal, regional, and federal education system levels.
Primary competencies for secondary school: psychological features of successful learning at transition grades
Authors: Yanishevskaya Maria , Vysotskaya Elena , Lobanova Anastasia
Published: March 2021

As the transition period from primary to secondary education is difficult for many students, our strive is to study the psychological features, which may scaffold student’s promotion and provide for future successful learning. We consider the educational media to be a complex system of psychological features, which depend on the content of education and the way, in which the educational process is organized. The “activity-and-content oriented” educational media devised after theoretical principles of the Developmental Instruction (Davydov), according to our hypothesis, provides sound bases for primary competencies formation, which are vital for secondary education. To test this assumption, we have diagnosed the quality of reflection, analysis, planning, model-acquisition and model-application, achieved by 204 students from two different educational media (“activity-and-content oriented” and “knowledge oriented”). For assessment purposes two diagnostic tools were used: “Transpositions” and “Moon” test. Both tests exploited contexts, which were unfamiliar to both groups of students. The results show, that students from the “activity-and-content” oriented educational media performed significantly better in most cognitive primary concepts. We consider these findings to support our major hypothesis, that educational media is a powerful source to scaffold students’ primary competencies’ formation, which in its turn provides for successful learning in secondary school.
Implementation of an individual educational route in inclusive practice
Authors: Titova Oksana , Bratkova Margarita , Karanevskaya Olga , Gravitskaya Elena , Barbakadze Irma
Published: March 2021

There is currently a trend towards an increase in the number of children with special educational needs enrolled in inclusive schools. Thus, the number of children with special educational needs enrolled in inclusive schools is growing. This is caused both by significant changes in the legal regulatory framework, including the 2012 Federal Law on Education, the adoption of the Federal State Educational Standard of Primary General Education for Children with Special Needs, etc. and by the fact that in some regions the number of specialized schools is decreasing, inclusive education becomes a more affordable option for children with special education needs. School specialists, parents, and the public engage in an active dialogue about choosing the most efficient path for an educational route for special needs children, comparing the advantages and disadvantages of inclusive and special education. The design and implementation of an individual educational route, an individual curriculum is essential for children with special needs in terms of improving the quality of education and efficiently entering social life. The relevance of the study is determined by identifying the components that facilitate and complicate, hinder the development and implementation of an individual educational route for these children in an educational organization; the determination of the content of an individual educational route based on the current situation in a practical institution considering the requirements of inclusive education. The purpose of the study is to explore the problems of developing and implementing individual educational routes for children with special needs in the context of inclusion and to determine ways to solve these problems. The key methods of the study are a questionnaire and a structured interview. The empirical data confirms the assumption that the development and implementation of an individual educational route for children with special needs in an educational organization are problematic and inefficient for several reasons. The data obtained is new since similar research results have not been found in the open sources over the past five years.