bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous switching of two different CO2-switchable amines in the same solution
Authors: Sanger Matthew , Barker Daniel , Jessop Philip G.
Published: April 2024

The application or removal of CO2 can simultaneously trigger the switching of two different amines, but only if limitations on basicity and concentration are met.
Computational insights into the binding modes, keto–enol tautomerization and stereo-electronically controlled decarboxylation of oxaloacetate in the active site of macrophomate synthase
Authors: Li Xinyi , Zhang Fa-Guang , Ma Jun-An , Liu Yongjun
Published: April 2024

QM/MM calculations revealed dominant binding modes, keto–enol tautomerization and decarboxylation of oxaloacetate in the active site of macrophomate synthase. The water-assisted tautomerization was calculated to be easier than decarboxylation.
Nickel-embedded zeolite subcrystal catalyst: rapid enhancement of activity and metal impurity resistance in the hydrodesulfurization of 4,6-dimethyldibenzothiophene
Authors: Tan Zhichao , Du Ke , Sheng Zhizheng , Li Wanyi , Zhu Huihong , Gao Lou , Li He , Tang Yi , Zhang Yahong
Published: April 2024

Ni nanoparticles embedded in an Al-containing MFI zeolite subcrystal (<7 nm) lead to superior hydrodesulfurization activity and exceptional resistance to Ni/V metal impurities.
Epitaxial heterointerfacial electron bridge synchronizes oxygen evolution activity and stability on a layered double hydroxide surface
Authors: Wang Jia , Zhao Zelin , Guo Min , Xiao Liang , Tang Haolin , Li Jiantao , Kou Zongkui , Li Junsheng
Published: April 2024

Scalable green hydrogen production via electrocatalytic water splitting is largely restricted by the insufficient activity and stability of oxygen evolution reaction (OER) catalysts at the anode.
Plant phytochemicals as bio-responsive compounds in smart packaging for food spoilage detection: a comprehensive review
Authors: Akhila Konala , Ramakanth Dakuri , Lakshman Rao Lingala , Singh Suman , Gaikwad Kirtiraj K.
Published: April 2024

With growing consumer concern for eating fresh and nutritious food, there arises a demand for freshness indicators to build consumer trust and brand value.
High-protein high-konjac glucomannan diets changed glucose and lipid metabolism by modulating colonic microflora and bile acid profiles in healthy mouse models
Authors: Xu Yetong , Zhou Chengyu , Zong Minyue , Zhu Junwei , Guo Xutong , Sun Zhihong
Published: April 2024

Dietary protein and fiber contents showed interactions in signaling pathways related to lipid and glucose metabolism and the inflammatory status of mice.
Punicic acid ameliorates obesity-related hyperlipidemia and fatty liver in mice via regulation of intestinal flora and lipopolysaccharide-related signaling pathways
Authors: Chen Liping , Lei Yifan , Lu Changxin , Liu Dingyang , Ma Wenyu , Lu Hengqian , Wang Yongzhong
Published: April 2024

Punicic acid ameliorates obesity-related hyperlipidemia and fatty liver in mice via regulation of intestinal flora and lipopolysaccharide-related TLR4/MyD88/NF-κB and TLR4/IL-22/STAT3 signaling pathways.
Comparative analysis of tropomyosin allergenicity in three different species of molluscs: insights into the role of amino acid composition in IgE epitopes
Authors: Han Xinyu , He Xinrong , Wang Xinya , Luo Lianzhong , Li Yubao , Lai Dong , Liu Hong , Liu Jingwen , Rao Shitao , Liu Guangming
Published: April 2024

Compared to the other two TM variants (ATM and MTM), HTM exhibited lower allergenicity and elicited a lower IL-4/IFN-γ ratio due to its higher proportion of non-polar amino acids and a lower number of polar hydrogen bonds in IgE epitopes.
Hydride-free reduction of propargyl electrophiles: a nickel-catalyzed photoredox strategy for allene synthesis
Authors: Hu Tingjun , Fagué Vincent , Bouyssi Didier , Monteiro Nuno , Amgoune Abderrahmane
Published: April 2024

Herein we report a photocatalytic reduction of propargyl carbonates to allenes mediated by a nickel molecular catalyst without any hydride source. The reduction process is enabled by the amine that plays a dual role as a reductant and a proton source.
Advances in electrosynthesis for a greener chemical industry
Authors: Chen Season S. , Glezakou Vassiliki-Alexandra , Holewinski Adam , Lopez-Ruiz Juan , Tessonnier Jean-Philippe
Published: April 2024

This themed collection gathers together articles on advances in electrosynthesis for a greener chemical industry.
Integrated high performance microfluidic organic analysis instrument for planetary and space exploration
Authors: Butterworth Anna L. , Golozar Matin , Estlack Zachary , McCauley Jeremy , Mathies Richard A. , Kim Jungkyu
Published: April 2024

This work presents the design, fabrication, and automation of our space flight-format microfabricated sample processing and capillary electrophoresis analysis instrument.
Design, docking optimization, and evaluation of biotin-PEG4-1,8-naphthalimide as a potent and safe antitumor agent with dual targeting of ferroptosis and DNA
Authors: Wang Qi , Liang Si-Min , Mao Zhi-Chen , Ma Xian-Li , Wei Jian-Hua , Huang Ri-Zhen , Zhang Ye
Published: April 2024

A set of biotin-polyethylene glycol (PEG)-naphthalimide derivatives 4a–4h with dual targeting of ferroptosis and DNA were designed and optimized using docking simulation as antitumor agents.
Hydroquinone colorimetric sensing based on core–shell structured CoFe2O4@N-GQDs@CeO2 nanocomposites as oxidase mimics
Authors: Lei Xuefang , Li Yujin , Guo Peiqing , Qiu Mingzhu , Meng Rang , Li Shaohui , Zhang Dongxia , Chen Nali , Zhou Xibin
Published: April 2024

The core–shell structured CoFe2O4@N-GQDs@CeO2 nanocomposites were successfully synthesized by co-precipitation method, and CeO2 was uniformly dispersed on the shell layer with the help of nitrogen-doped graphene quantum dots (N-GQDs).
A novel electrochemical biosensor based on WO3@AuNPs and HBP@BIBB macromolecule-triggered ATRP for DR1 detection
Authors: Cui Xiaojing , Zhang Yaping , Zhang Hanmeng , Yang Huaixia , Liu Yanju , Si Fuchun
Published: April 2024

An electrochemical sensor for DR1 detection based on WO3@AuNPs and the HBP@BIBB macromolecule-initiated ATRP signal amplification strategy was constructed.
Light-driven dynamical tuning of the thermal conductivity in ferroelectrics
Authors: Cazorla Claudio , Bichelmaier Sebastian , Escorihuela-Sayalero Carlos , Íñiguez Jorge , Carrete Jesús , Rurali Riccardo
Published: April 2024

Dynamical tuning of the thermal conductivity is critical for the development of novel phononic devices. Here, we show that such a control can be efficiently achieved in a wide class of ferroelectrics by a photoinduced phase transition.
A water mediated multicomponent reaction for the synthesis of novel spirooxindole derivatives and their antifungal activity
Authors: Zhang Min , Shi Liang , Chen Li , Liu Zhengyu , Zhao Ting , Zhu Chunyin , Yang Liuqing
Published: April 2024

A total of 27 novel spirooxindoles were synthesized through a water mediated three-component reaction of isatin, 4-aminocoumarin, and 1,3-cyclodicarbonyl compounds. Several compounds showed excellent antifungal activity against Physalospora piricola.
BODIPY(aryl)iodonium salts in the efficient synthesis of diversely functionalized BODIPYs and selective detection of serum albumin
Authors: Kumar Bintu , Bhatta Anindita , Saraf Prakriti , Pandurang Taur Prakash , Rangan Krishnan , Sarkar Madhushree , Mitra Sivaprasad , Kumar Dalip
Published: April 2024

Using readily available BODIPY and iodoarenes various BODIPY(aryl)iodonium salts were prepared and successfully utilized for the direct syntheses of functionalized BODIPYs, bis-BODIPYs and for the selective detection of serum protein.
Integrating multiple regulatory strategies: phase, morphology and interface engineering to construct a hierarchical Ni2P–MoS2/rGO heterostructure catalyst for efficient oxygen reduction reaction
Authors: Wang Xinyi , Jin Jing , Gao Zeyuan , Hou Li , Tao Xiwen , Wang Jing , Zhao Yueqi , Gao Faming
Published: April 2024

Two-dimensional (2D) molybdenum disulfide (MoS2) with a large surface area and unique electronic properties has emerged as a promising noble metal-free catalyst for electrochemical energy storage/conversion applications.
Improved antioxidative and antibacterial activity of epigallocatechin gallate derivative complexed by zinc cations and chitosan
Authors: Zhao Jingjing , Qian Dou , Zhang Luyang , Wang Xiao , Zhang Jianfeng
Published: April 2024

Preparation of EGCG–Zn–CS using Microwave Irradiation method with excellent biological activity.
Preparation of a novel antibacterial magnesium carbonate coating on a titanium surface and its in vitro biocompatibility
Authors: Xiang Shougang , Zhang Chengdong , Guan Zhenju , Li Xingping , Liu Yumei , Feng Gang , Luo Xuwei , Zhang Bo , Weng Jie , Xiao Dongqin
Published: April 2024

We report deposition of a MgCO3 coating on titanium surfaces using a hydrothermal method, followed by hydrogen peroxide treatment. The coating demonstrated antibacterial properties and enhanced osteogenic differentiation of BMSC.
Cyanoremediation of heavy metals (As(v), Cd(ii), Cr(vi), Pb(ii)) by live cyanobacteria (Anabaena variabilis, and Synechocystis sp.): an eco-sustainable technology
Authors: Hossain Md. Sabbir , Okino Tatsufumi
Published: April 2024

Cyanoremediation of heavy metals by surface adsorption of live cyanobacteria represents a promising technique for wastewater treatment.
Multiscale mechanical characterization of biobased photopolymers towards sustainable vat polymerization 3D printing
Authors: Lublin Derek , Hao Taige , Malyala Raj , Kisailus David
Published: April 2024

In vat polymerization (VP) 3D printing, there is an urgent need to expand characterization efforts for resins derived from natural resources to counter the increasing consumption of fossil fuels required to synthesize conventional monomers.
Novel pyrazole and imidazolone compounds: synthesis, X-ray crystal structure with theoretical investigation of new pyrazole and imidazolone compounds anticipated insecticide’s activities against targeting Plodia interpunctella and nilaparvata lugens
Authors: Shalaby Mona A. , BinSabt Mohammad H. , Rizk Sameh A. , Fahim Asmaa M.
Published: April 2024

In this study, (2-propoxyphenyl)(3-(p-tolyl)oxiran-2-yl)methanone was synthesised by oxidizing the double bond of the respective chalcone via the Weitz–Scheffer epoxidation reaction. The insecticidal activities of the newly synthesized compounds were tested with computional investigation.
UV-assisted synthesis of ultra-small GO–Austar for efficient PTT therapeutic architectonic construction
Authors: Gao Ang , Pei Lijia , Liu Guan , Chen Yunsheng , Zhang Amin , Cui Daxiang
Published: April 2024

UV-assisted synthesis GO–Austar complexes accomplished synergistic gastric cancer photothermal therapy.
Enhanced microwave absorption performance of Fe3Al flakes by optimizing the carbon nanotube coatings
Authors: Luo Xixi , Xie Hui , Cao Jing , Lu Yaru , Tao Shiping , Meng Zhixing , Pu Lingna , Sun Liyang , He Pengjia , Liu Ziyan
Published: April 2024

Fe3Al is a good magnetic loss absorber for microwave absorption.
LC-MS/DIA-based strategy for comprehensive flavonoid profiling: an Ocotea spp. applicability case
Authors: Alves Matheus Fernandes , Katchborian-Neto Albert , Bueno Paula Carolina Pires , Carnevale-Neto Fausto , Casoti Rosana , Ferreira Miller Santos , Murgu Michael , de Paula Ana Claudia Chagas , Dias Danielle Ferreira , Soares Marisi Gomes , Chagas-Paula Daniela Aparecida
Published: April 2024

A user-friendly LC-MS data-independent acquisition-based strategy using open software for access to the flavonoid content of complex mixtures.
Siloxide tripodal ligands as a scaffold for stabilizing lanthanides in the +4 oxidation state
Authors: Tricoire Maxime , Hsueh Fang-Che , Keener Megan , Rajeshkumar Thayalan , Scopelliti Rosario , Zivkovic Ivica , Maron Laurent , Mazzanti Marinella
Published: April 2024

Robust arene-anchored polydentate siloxide ligands allow to control unwanted ligand rearrangements for the isolation of Tb(iv) complexes thus enabling the use of the Tb(iii)/Tb(iv) couple for the separation of Tb from the neighboring Dy ion.
A tin analogue of propadiene with cumulated CSn double bonds
Authors: Sugamata Koh , Asakawa Teppei , Minoura Mao
Published: April 2024

The first stable linear 2-stannapropadiene has been synthesized. The inert-pair effect favors Sn2+, but silyl substituents can counter it, enabling the isolation of 2-stannapropadiene with a Sn4+.
Electrocatalytic functional group conversion-based carbon resource upgrading
Authors: Si Di , Teng Xue , Xiong Bingyan , Chen Lisong , Shi Jianlin
Published: April 2024

The reported electrocatalytic upgrading reactions of carbon resources are summarized in four categories based on the types of functional groups from the aspects of activation, cleavage and formation of chemical bonds.
Wide band gap selenide infrared nonlinear optical materials AIIMg6Ga6Se16 with strong SHG responses and high laser-induced damage thresholds
Authors: Wang Linan , Chu Dongdong , Yang Zhihua , Li Junjie , Pan Shilie
Published: April 2024

Three double alkaline-earth metal selenides AIIMg6Ga6Se16 (AII = Ca, Sr, Ba) with excellent optical properties have been rationally designed, and fabricated by high temperature solid-state reactions.
An anthraquinone-based bismuth–iron metal–organic framework as an efficient photoanode in photoelectrochemical cells
Authors: Shi Cai , Gomez-Mendoza Miguel , Gómez de Oliveira Eloy , García-Tecedor Miguel , Barawi Mariam , Esteban-Betegón Fátima , Liras Marta , Gutiérrez-Puebla Enrique , Monge Angeles , de la Peña O'Shea Víctor A. , Gándara Felipe
Published: April 2024

A new metal–organic framework formed by iron and bismuth, and an anthraquinone linker is demonstrated to be an efficient photoanode in photoelectrochemical cells. An intermediate anion radical is generated under visible light, with a long lifetime.
Iron promoted end-on dinitrogen-bridging in heterobimetallic complexes of uranium and lanthanides
Authors: Jori Nadir , Moreno Juan J. , Shivaraam R. A. Keerthi , Rajeshkumar Thayalan , Scopelliti Rosario , Maron Laurent , Campos Jesús , Mazzanti Marinella
Published: April 2024

End-on bridging dinitrogen binding to U(iii), Ln(iii) and Ln(ii) is favoured for the iron-bound N2 compared to free N2, resulting in increased N2 activation with increasing Ln Lewis acidity with a back-bonding contribution only found for U(iii).
Highly stereoselective α-glycosylation with GalN3donors enabled collective synthesis of mucin-related tumor associated carbohydrate antigens
Authors: Shou Kunxiu , Zhang Yunqin , Ji Yujie , Liu Bin , Zhou Qingli , Tan Qiang , Li Fuying , Wang Xiufang , Lu Gang , Xiao Guozhi
Published: April 2024

Collective synthesis of mucin-related tumor associated carbohydrate antigens has been achievedviathis new α-glycosylation method with GalN3donors, which features mild conditions, broad substrate scope, high yields and stereoselectivities.
Unraveling the mechanisms of triplet state formation in a heavy-atom free photosensitizer
Authors: Fay Thomas P. , Limmer David T.
Published: April 2024

Triplet excited states play a pivotal role in photosensitizers. Detailed simulations reveal how these states are formed efficiently in heavy-atom free systems.
Self-powered triboelectric nanogenerator with enhanced surface charge density for dynamic multidirectional pressure sensing
Authors: Wu Jiaqi , Zhang Yu , Zheng Xin Ting
Published: April 2024

A self-powered triboelectric nanogenerator based pressure sensor (STEPs) is developed via material doping and morphology tuning to achieve sensitive multidirectional sensing, showing great potential for motion monitoring and human–machine interactions.
Coated electrodes for liquid thermoelectric conversion devices to enhance Fe2+/Fe3+ redox kinetics
Authors: Aiba Touya , Inoue Dai , Moritomo Yutaka
Published: April 2024

A graphite-dispersion coated electrode enhances the output power of a LTE by 37.5% as compared with that of a LTE composed of a conventional graphite sheet.
Upcycling of low value end-of-life cathode material into next generation cathode materials
Authors: Madge R. , Jarvis A. , Lima da Silva W. , Driscoll L. L. , Anderson P. A. , Slater P. R.
Published: April 2024

Low value Mn based spinel from an EOL EV battery is selectively leached and upcycled to higher value next generation cathode materials.
Synthesis of efficient submicron γ-AlON Mn2+, Mg2+ phosphors for mini-LEDs by a coprecipitation precursor method
Authors: Su Zhezhe , Wang Yuhua , Seto Takatoshi
Published: April 2024

The coprecipitation precursor (COP) method was employed to prepare a narrow band green phosphor, γ-AlON Mn2+, Mg2+, for mini-LED displays.
Synergistic action of synthetic peptides and amphotericin B causes disruption of the plasma membrane and cell wall in Candida albicans
Authors: Souza Thayna A.M. , Mello Erica O. , Taveira Gabriel B. , Moreira Felipe F. , Seabra Sergio Henrique , Carvalho André O. , Gomes Valdirene M.
Published: April 2024

The objective of this work was to evaluate the combination of synthetic peptides based on the γ-core motif of defensin PvD1 with amphotericin B (AmB) at different concentrations against Candida albicans. We applied the checkerboard assay using different concentrations of the commercial drug AmB and the synthetic peptides γ31-45PvD1++ and γ33-41PvD1++ against C. albicans, aiming to find combinations with synergistic interactions. Between these two interactions involving γ31-45PvD1++ and AmB, an additive effect was observed. One such interaction occurred at concentrations of 0.009 µM of peptide γ31-45PvD1++ and 13.23 µM of AmB and another condition of 0.019 µM of peptide γ31-45PvD1++ and 6.61 µM of AmB. The other two concentrations of the interaction showed a synergistic effect in the combination of synthetic peptide γ31-45PvD1++ and AmB, where the concentrations were 1.40 µM peptide γ31-45PvD1++ and 0.004 µM AmB and 0.70 µM γ31-45PvD1++ peptide and 0.002 µM AmB. We proceeded with analysis of the mechanism of action involving synergistic effects. This examination unveiled a range of impactful outcomes, including the impairment of mitochondrial functionality, compromise of cell wall integrity, DNA degradation, and a consequential decline in cell viability. We also observed that both synergistic combinations were capable of causing damage to the plasma membrane and cell wall, causing leakage of intracellular components. This discovery demonstrates for the first time that the synergistic combinations found between the synthetic peptide γ31-45PvD1++ and AmB have an antifungal effect against C. albicans, acting on the integrity of the plasma membrane and cell wall.
The molecular mechanisms driving Plasmodium cell division
Authors: Guttery David S. , Zeeshan Mohammad , Holder Anthony A. , Tewari Rita
Published: April 2024

Malaria, a vector borne disease, is a major global health and socioeconomic problem caused by the apicomplexan protozoan parasite Plasmodium. The parasite alternates between mosquito vector and vertebrate host, with meiosis in the mosquito and proliferative mitotic cell division in both hosts. In the canonical eukaryotic model, cell division is either by open or closed mitosis and karyokinesis is followed by cytokinesis; whereas in Plasmodium closed mitosis is not directly accompanied by concomitant cell division. Key molecular players and regulatory mechanisms of this process have been identified, but the pivotal role of certain protein complexes and the post-translational modifications that modulate their actions are still to be deciphered. Here, we discuss recent evidence for the function of known proteins in Plasmodium cell division and processes that are potential novel targets for therapeutic intervention. We also identify key questions to open new and exciting research to understand divergent Plasmodium cell division.
Solid-state nuclear magnetic resonance in the structural study of polyglutamine aggregation
Authors: van der Wel Patrick C.A.
Published: April 2024

The aggregation of proteins into amyloid-like fibrils is seen in many neurodegenerative diseases. Recent years have seen much progress in our understanding of these misfolded protein inclusions, thanks to advances in techniques such as solid-state nuclear magnetic resonance (ssNMR) spectroscopy and cryogenic electron microscopy (cryo-EM). However, multiple repeat-expansion-related disorders have presented special challenges to structural elucidation. This review discusses the special role of ssNMR analysis in the study of protein aggregates associated with CAG repeat expansion disorders. In these diseases, the misfolding and aggregation affect mutant proteins with expanded polyglutamine segments. The most common disorder, Huntington's disease (HD), is connected to the mutation of the huntingtin protein. Since the discovery of the genetic causes for HD in the 1990s, steady progress in our understanding of the role of protein aggregation has depended on the integrative and interdisciplinary use of multiple types of structural techniques. The heterogeneous and dynamic features of polyQ protein fibrils, and in particular those formed by huntingtin N-terminal fragments, have made these aggregates into challenging targets for structural analysis. ssNMR has offered unique insights into many aspects of these amyloid-like aggregates. These include the atomic-level structure of the polyglutamine core, but also measurements of dynamics and solvent accessibility of the non-core flanking domains of these fibrils' fuzzy coats. The obtained structural insights shed new light on pathogenic mechanisms behind this and other protein misfolding diseases.
3D shape knowledge graph for cross‐domain 3D shape retrieval
Authors: Chang Rihao , Ma Yongtao , Hao Tong , Wang Weijie , Nie Weizhi
Published: April 2024

The surge in 3D modelling has led to a pronounced research emphasis on the field of 3D shape retrieval. Numerous contemporary approaches have been put forth to tackle this intricate challenge. Nevertheless, effectively addressing the intricacies of cross‐modal 3D shape retrieval remains a formidable undertaking, owing to inherent modality‐based disparities. The authors present an innovative notion—termed “geometric words”—which functions as elemental constituents for representing entities through combinations. To establish the knowledge graph, the authors employ geometric words as nodes, connecting them via shape categories and geometry attributes. Subsequently, a unique graph embedding method for knowledge acquisition is devised. Finally, an effective similarity measure is introduced for retrieval purposes. Importantly, each 3D or 2D entity can anchor its geometric terms within the knowledge graph, thereby serving as a link between cross‐domain data. As a result, the authors’ approach facilitates multiple cross‐domain 3D shape retrieval tasks. The authors evaluate the proposed method's performance on the ModelNet40 and ShapeNetCore55 datasets, encompassing scenarios related to 3D shape retrieval and cross‐domain retrieval. Furthermore, the authors employ the established cross‐modal dataset (MI3DOR) to assess cross‐modal 3D shape retrieval. The resulting experimental outcomes, in conjunction with comparisons against state‐of‐the‐art techniques, clearly highlight the superiority of our approach.
An optimal calibration factor for mutual information effective SINR mapping scheme in 5G NR
Authors: Kim Hyeongseok , Seol Kwon , Kim Jeongchang
Published: April 2024

In this letter, an optimal calibration factor for mutual information effective signal‐to‐interference‐plus‐noise ratio (SINR) mapping (MIESM) scheme in fifth‐generation new radio (5G NR) is provided. By applying the optimal calibration factor to the MIESM scheme, the estimation accuracy of the effective SINR can be improved. The optimal calibration factor minimizes the mean squared error (MSE) of the difference between the estimated effective SINR and the required SNR under additive white Gaussian noise (AWGN) at a block error rate (BLER) of 10%. Simulation results show that the optimized MIESM scheme outperforms the non‐optimized MIESM scheme.
Milne‐Hamming discretized zeroing neural networks for solving time‐varying linear systems
Authors: Chen Xi , Kong Ying , Zeng Xuxiang , Yin Jiayue
Published: April 2024

Time‐varying linear systems (TVLS) is a vital mathematical problem in many engineering fields. In this letter, a Milne‐Hamming discretized zeroing neural networks (MHDZNN) is presented to solve the TVLS, where high accurate convergence is got by combing Milne‐Hamming (MH) method. Theoretical analyses of its convergence and precision are discussed to illustrate the validity of the Milne‐Hamming DZNN (MHDZNN). Furthermore, numerical experiments compared with the two existing DZNN models are simulated to verify the superiority of the proposed MHDZNN model.
Towards an antibacterial self‐healing coating based on linseed oil/ZnO nanoparticles repair agent, encapsulated in polyurea formaldehyde microcapsules
Authors: Karampoor Mohammad Reza , Bahrami Abbas , Atapour Masoud
Published: April 2024

This research aims at investigating the idea of anti‐bacterial self‐healing coatings based on polyurea formaldehyde microcapsules (MCs), with the repair agent being ZnO‐containing linseed oil. ZnO nanoparticles were added to the repair agent with the idea of developing an antibacterial coating. The idea was to entrap some ZnO nanoparticles inside microcapsules, aiming for some local release of ZnO nanoparticles where the coating is damaged. The corrosion resistances of the coatings were studied using the Tafel polarization test. The structure of the coating samples was evaluated using a scanning electron microscope. To check the antibacterial properties of ZnO‐containing self‐healing samples, Escherichia coli and Staphylococcus aureus bacteria were used. Results showed that ZnO nanoparticles were distributed not only inside microcapsules but also over the walls, inferring that overall protection can also be attained in addition to local anti‐bacterial performance. Results showed that the proposed multi‐functional coating has promising antibacterial and self‐healing responses.
JADES
Authors: Maiolino Roberto , Übler Hannah , Perna Michele , Scholtz Jan , D’Eugenio Francesco , Witten Callum , Laporte Nicolas , Witstok Joris , Carniani Stefano , Tacchella Sandro , Baker William M. , Arribas Santiago , Nakajima Kimihiko , Eisenstein Daniel J. , Bunker Andrew J. , Charlot Stéphane , Cresci Giovanni , Curti Mirko , Curtis-Lake Emma , de Graaff Anna , Egami Eiichi , Ji Zhiyuan , Johnson Benjamin D. , Kumari Nimisha , Looser Tobias J. , Maseda Michael , Nelson Erica , Robertson Brant , Rodríguez Del Pino Bruno , Sandles Lester , Simmonds Charlotte , Smit Renske , Sun Fengwu , Venturi Giacomo , Williams Christina C. , Willmer Christopher N. A.
Published: April 2024

Finding the first generation of stars formed out of pristine gas in the early Universe, known as Population III (PopIII) stars, is one of the most important goals of modern astrophysics. Recent models have suggested that PopIII stars may form in pockets of pristine gas in the halo of more evolved galaxies. We present NIRSpec integral field spectroscopy and micro-shutter array spectroscopic observations of the region around GN-z11, an exceptionally luminous galaxy atz = 10.6, that reveal a greater than 5σdetection of a feature consistent with being HeIIλ1640 emission at the redshift of GN-z11. The very high equivalent width of the putative HeII emission in this clump (log(EWrest(HeII)/Å) = 1.79−0.25+0.15) and a lack of metal lines can be explained in terms of photoionisation by PopIII stars, while photoionisation by PopII stars is inconsistent with the data. The high equivalent width would also indicate that the putative PopIII stars likely have an initial mass function with an upper cutoff reaching at least 500M⊙. The PopIII bolometric luminosity inferred from the HeII line would be ∼7 × 109 L⊙, which would imply a total stellar mass formed in the burst of ∼2 × 105 M⊙. We find that photoionisation by the active galactic nucleus (AGN) in GN-z11 cannot account for the HeII luminosity observed in the clump but can potentially be responsible for an additional HeII emission observed closer to GN-z11. We also consider the possibility of in situ photoionisation by an accreting direct collapse black hole hosted by the HeII clump. We find that this scenario is less favoured, but it remains a possible alternative interpretation. We also report the detection of a Lyαhalo stemming out of GN-z11 and extending out to ∼2 kpc as well as resolved funnel-shaped CIII emission likely tracing the ionisation cone of the AGN.
Ancient stellar populations in the outskirts of nearby grand-design spirals: Investigation of their star formation histories
Authors: Lofaro Cristina Maria , Rodighiero Giulia , Enia Andrea , Werle Ariel , Bisigello Laura , Cassata Paolo , Casasola Viviana , Renzini Alvio , Scaloni Letizia , Bianchetti Alessandro
Published: April 2024

Context. The main sequence (MS) of star-forming galaxies (SFGs) is the tight relation between the galaxy stellar mass (M⋆) and its star formation rate (SFR) and was observed up to z ∼ 6. The MS relation can be used as a reference for understanding the differences among galaxies, which are characterised by different rates of stellar production (starbursts, SFGs, and passive galaxies), and those inside a galaxy that is made up of different components (bulge, disk, and halo). To investigate peculiar features found in our galaxies sample in more depth, we focus here on their star formation history (SFH).

Aims. The SFHs are a fundamental tool for revealing the galaxy path from the earlier stages of formation to the present time. The various phases of galaxy evolution are imprinted on the source spectrum globally and locally. Thus, we are able to interpret the dynamical origin of the spirals quantitatively and distinguish between in situ or ex situ formation processes.

Methods. We performed a spectral energy distribution fitting procedure that accounted for the energetic balance between UV (observed) and far-IR (optically obscured) radiation on a sample of eight nearby face-on grand-design spiral galaxies from the DustPedia sample. This approach allowed us to study the spatially resolved MS of the sample and to recover the past SFH by accounting for attenuation due to the presence of dust. By exploiting the BAGPIPES code, we constrained the SFHs for each galaxy with a delayed exponentially declining model to derive their mass-weighted age (tMW).

Results. The spiral galaxies in our sample have similar radial tMW trends overall. A central old region (tMW up to ∼7 Gyr, consistent with the presence of a bulge for various systems) is followed by younger regions in which the disks are still forming stars (tMW ∼ 4 Gyr). At larger distances from the centre of the galaxies, tMW increases mildly in general. Strikingly, in two galaxies (NGC4321 and NGC5194), we found a steep increase in tMW that reached levels similar to those of the bulge. These old stellar populations in the very galaxy outskirts, which are also detectable as “quenched rings” below the spatially resolved MS, is unexpected. We discuss their potential origin by considering the different gas phases (HI and H2) of the source with the most prominent quenched ring, NGC4321, and argue for two main possibilities: (1) some environmental effect (e.g. starvation) could affect the outer edge of the galaxies or (2) the circumgalactic medium of sources outside of high-density clusters might have stopped to supply pristine gas to the galaxy (e.g. if its specific angular moment is too high for being accreted).
Onset of penumbra formation
Authors: García-Rivas M. , Jurčák J. , Bello González N. , Borrero J. M. , Schlichenmaier R. , Lindner P.
Published: April 2024

Context. Fully fledged penumbrae have been widely studied both observationally and theoretically. Yet the relatively fast process of penumbra formation has not been studied closely with high spatial resolution.

Aims. We investigate the stages previous to and during the formation of penumbral filaments in a developing sunspot.

Methods. We analysed Milne-Eddington inversions from spectro-polarimetric data of the leading sunspot of NOAA 11024 during the development of its penumbra. We focused on selected areas of this protospot in which segments of penumbra develop.

Results. We find that few types of distinctive flow patterns develop at the protospot limb and centre sides previous to penumbra formation. The flow in the centre side is often characterised by a persistent (> 20 min) inflow-outflow pattern extending radially over 4 arcsec at the direct periphery of the protospot umbra. This inflow-outflow system often correlates with elongated granules, as seen in continuum intensity maps, and is also coupled with magnetic bipolar patches at its edges, as seen in magnetograms. The field is close to horizontal between the bipolar patches, which is indicative of its possible loop configuration. All of these aspects are analogous to observations of magnetic flux emergence. In the protospot limb side, however, we observed a mostly regular pattern associated with small granules located near the protospot intensity boundary. Locally, an inflow develops adjacent to an existing penumbral segment, and this inflow is correlated with a single bright penumbral filament that is brighter than filaments containing the Evershed flow. All investigated areas at the centre and limb side eventually develop penumbral filaments with an actual Evershed flow that starts at the umbral boundary and grows outwards radially as the penumbral filaments become longer in time.
Narrow absorption lines from intervening material in supernovae
Authors: González-Gaitán Santiago , Gutiérrez Claudia P. , Anderson Joseph P. , Morales-Garoffolo Antonia , Galbany Lluis , Goswami Sabyasachi , Mourão Ana M. , Mattila Seppo , Sullivan Mark
Published: April 2024

Narrow absorption features in nearby supernova (SN) spectra are a powerful diagnostic of the slow-moving material in the line of sight: they are extensively used to infer dust extinction from the host galaxies, and they can also serve in the detection of circumstellar material originating from the SN progenitor and present in the vicinity of the explosion. Despite their wide use, very few studies have examined the biases of the methods to characterize narrow lines, and not many statistical analyses exist. This is the first paper of a series in which we present a statistical analysis of narrow lines of SN spectra of various resolutions. We developed a robust automated methodology to measure the equivalent width (EW) and velocity of narrow absorption lines from intervening material in the line of sight of SNe, including Na I D, Ca II H&K, K I, and diffuse interstellar bands. We carefully studied systematic biases in heterogeneous spectra from the literature by simulating different signal-to-noise, spectral resolution, size and orientation of the slit, and we present the real capabilities and limitations of using low- and mid-resolution spectra to study these lines. In particular, we find that the measurement of the EW of the narrow lines in low-resolution spectra is highly affected by the evolving broad P-Cygni profiles of the SN ejecta, both for core-collapse and type Ia SNe, inducing a conspicuous apparent evolution. Such pervading non-physical evolution of narrow lines might lead to wrong conclusions on the line-of-sight material, for example concerning circumstellar material ejected from the SN progenitors. We thus present an easy way to detect and exclude those cases to obtain more robust and reliable measurements. Finally, after considering all possible effects, we analysed the temporal evolution of the narrow features in a large sample of nearby SNe to detect any possible variation in their EWs over time. We find no time evolution of the narrow line features in our large sample for all SN types.
Cosmic hide and seek: The volumetric rate of X-ray quasi-periodic eruptions
Authors: Arcodia R. , Merloni A. , Buchner J. , Baldini P. , Ponti G. , Rau A. , Liu Z. , Nandra K. , Salvato M.
Published: April 2024

Multiwavelength extragalactic nuclear transients, particularly those detectable as multi-messengers, are among the primary drivers for the next-generation observatories. X-ray quasi-periodic eruptions (QPEs) are the most recent and perhaps most peculiar addition to this group. Here, we report a first estimate of the volumetric rate of QPEs based on the first four discoveries with the eROSITA X-ray telescope onboard the Spectrum Roentgen Gamma observatory. Under the assumption, supported by a suite of simulated light curves, that these four sources sample the intrinsic population somewhat homogeneously, we correct for their detection efficiency and compute a QPE abundance of Rvol = 0.60−0.43+4.73 × 10−6 Mpc−3 above an intrinsic average log L0.5−2.0 keVpeak > 41.7. Since the exact lifetime of QPEs (τlife) is currently not better defined than between a few years or few decades, we convert this to a formation rate of ℛvol/τlife ≈ 0.6 × 10−7(τlife/10 yr)−1 Mpc−3 yr−1. As a comparison, this value is a factor ∼10 τlife times smaller than the formation rate of tidal disruption events. The origin of QPEs is still debated, although lately most models suggest that they are the electromagnetic counterpart of extreme mass ratio inspirals (EMRIs). In this scenario, the QPE rate would thus be the first ever constraint (i.e. a lower limit) to the EMRI rate from observations alone. Future discoveries of QPEs and advances in their theoretical modeling will consolidate or rule out their use for constraining the number of EMRIs detectable by the LISA mission.
A proposal to improve the accuracy of cosmological observables and address the Hubble tension problem
Authors: Foidl Horst , Rindler-Daller Tanja
Published: April 2024

Context. Cosmological observational programs often compare their data not only with Λ cold dark matter (ΛCDM), but also with extensions applying dynamical models of dark energy (DE), whose time-dependent equation of state (EoS) parameters w differ from that of a cosmological constant. We found a degeneracy in the customary computational procedure for the expansion history of cosmological models once dynamical models of DE models were applied. This degeneracy, given the Planck-based Hubble constant H0, provides an infinite number of cosmological models reproducing the Planck-measured cosmic microwave background (CMB) spectrum, including the one with a cosmological constant. Moreover, this degeneracy biases the comparison of ΛCDM with dynamical DE extensions.

Aims. We present a complementary computational approach, that breaks this degeneracy in the computation of the expansion history of models with a dynamical DE component: the “fixed early densities (EDs)” approach evolves cosmological models from the early Universe to the present, in contrast to the customary “fixed H0” approach, which evolves cosmological models in reverse order. Although there are no equations to determine these EDs from first principles, we find they are accurately approximated by the ΛCDM model.

Methods. We implemented a refined procedure, applying both approaches, in an amended version of the code CLASS, where we focused on representative dynamical DE models using the Chevallier-Polarski-Linder (CPL) parametrization, studying cases with monotonically increasing and decreasing w over cosmic time.

Results. Our results reveal that a dynamical DE model with a decreasing w of the form w(a) = − 0.9 + 0.1(1 − a) could provide a resolution to the Hubble tension problem. Moreover, we find that combining the fixed EDs approach and the customary fixed H0 approach, while requesting to yield consistent results and being in agreement with observations across cosmic time, can serve as a kind of consistency check for cosmological models with a dynamical model of DE. Finally, we argue that implementing our proposed consistency check for cosmological models within current Markov chain Monte Carlo (MCMC) methods will increase the accuracy of inferred cosmological parameters significantly, in particular for extensions to ΛCDM.

Conclusions. Using our complementary computational scheme, we find characteristic signatures in the late expansion histories of cosmological models, allowing a phenomenological discrimination of DE candidates and a possible resolution to the Hubble tension, by ongoing and future observational programs.
Stellar obliquity measurements of six gas giants
Authors: Zak J. , Bocchieri A. , Sedaghati E. , Boffin H. M. J. , Prudil Z. , Skarka M. , Changeat Q. , Pascale E. , Itrich D. , Ivanov V. D. , Vitkova M. , Kabath P. , Roth M. , Hatzes A.
Published: April 2024

One can infer the orbital alignment of exoplanets with respect to the spin of their host stars using the Rossiter-McLaughlin effect, thereby giving us the chance to test planet formation and migration theories and improve our understanding of the currently observed population. We analyzed archival HARPS and HARPS-N spectroscopic transit time series of six gas giant exoplanets on short orbits, namely WASP-77 Ab, WASP-101b, WASP-103b, WASP-105b, WASP-120b, and WASP-131b. We find a moderately misaligned orbit for WASP-101b (λ = 34° ± 3) and a highly misaligned orbit for WASP-131b (λ = 161° ± 5), while the four remaining exoplanets appear to be aligned: WASP-77 Ab (λ = −8°−18+19), WASP-103b (λ = −2°−36+35), WASP-105b (λ = −14°−24+28), and WASP-120b (λ = −2° ± 4). For WASP-77 Ab, we are able to infer its true orbital obliquity (Ψ = 48°−21+22). We additionally performed transmission spectroscopy of the targets in search of strong atomic absorbers in the exoatmospheres, but were unable to detect any features, most likely due to the presence of high-altitude clouds or Rayleigh scattering muting the strength of the features. Finally, we comment on future perspectives on studying these planets with upcoming space missions to investigate their evolution and migration histories.
Determining stellar accretion rates from Paα and Brβ emission lines with JWST NIRSpec
Authors: Rogers Ciarán , de Marchi Guido , Brandl Bernhard
Published: April 2024

In this Letter, we present the first systematic spectroscopic measurements of the near-infrared (NIR) hydrogen recombination lines Paschen alpha (Paαλ = 1.875 μm) and Brackett beta (Brβλ = 2.626 μm), produced by pre-main-sequence (PMS) stars. Such stars include T Tauri and Herbig AeBe stars, located in the massive Galactic star-forming region NGC 3603. We used measurements obtained from JWST NIRSpec, using multi-object spectroscopy (MOS) mode. Based on the existing empirical relations between Lacc and LBrγ from the literature, we used our new measurements to formulate, for the first time, an empirical relationship between the accretion luminosity, Lacc, of the stars and the line luminosities, Lline, of both Paα and Brβ. These relationships are: log10(Lacc/L⊙) = 1.42(±0.18) × log10(LPaα/L⊙ + 3.33(±0.42) and log10(Lacc/L⊙) = 1.47(±0.18) × log10(LBrβ/L⊙) + 4.60(±0.57). These new relationships are key to establishing rough estimates of the accretion rates for large samples of PMS stars with JWST.
Gastrointestinale Symptome als Ausdruck einer komplizierten Malaria tropica
Authors: Kästner Matthias , Hemmer Christoph Josef , Reisinger Emil Christian
Published: April 2024

Anamnese Eine 42-jährige Patientin stellte sich wegen seit 2 Tagen bestehendem starkem Erbrechen, Durchfall, Fieber und Schüttelfrost vor. Zwei Wochen zuvor war die Patientin von einer Safari aus Tansania zurückgekehrt. Eine Chemoprophylaxe gegen Malaria hatte sie nicht eingenommen.

Untersuchungen und Diagnose Der Nachweis von Plasmodium falciparum führte zur Diagnose einer Malaria tropica. Das Blutbild zeigte eine Thrombozytopenie, die Sonografie eine Splenomegalie. Die Kriterien für eine komplizierte Malaria waren nicht erfüllt.

Therapie und Verlauf Die Patientin erhielt zunächst Atovaquon/Proguanil oral. Die Tabletten wurden nach Einnahme wiederholt erbrochen. Daher wurde die Therapie auf Artesunat i. v. umgestellt und die Patientin wurde auf der Intensivstation überwacht. Innerhalb von 22 Stunden sank die Parasitämie von 2,8 % auf 1,0 %. Die Therapie konnte nach 3 Tagen Artesunat i. v. mit Atovaquon/Proguanil oral zu Ende geführt werden und die Beschwerden klangen ab.

Folgerung Ausgeprägte gastrointestinale Symptome können auf ein drohendes Organversagen hinweisen. Eine an sich unkomplizierte Malaria mit anhaltendem Erbrechen sollte daher – wie die komplizierte Malaria – intravenös behandelt werden, und die Patienten sollten intensiv überwacht werden. Anhaltendes Erbrechen bei Malaria tropica ist als mögliches Kriterium für eine komplizierte Malaria anzusehen.
Was wissen Sie über … Trauma und Angststörungen?
Authors: Schmid Eva C.
Published: April 2024

Liebe Leser, testen Sie Ihr Wissen und frischen Sie Ihre Kenntnisse auf. Bitte kreuzen Sie jeweils eine Antwort an. Viel Spaß beim Beantworten wünscht Ihnen HP Eva C. Schmid!
Im Stressmodus
Authors: Schmid Eva C.
Published: April 2024

Für Angst- oder Paniksymptome müssen nicht allein psychische Faktoren verantwortlich sein. Auch eine Vielzahl von organischen Erkrankungen kann zu solchen Symptomen führen, was zunächst oft übersehen wird. Wechselwirkungen von körperlichen und psychogenen Ursachen erschweren die Abgrenzung. Umso wichtiger ist es, differenzialdiagnostisch physische Faktoren in Betracht zu ziehen und abzuklären. Am häufigsten treten Ängste im Zusammenhang mit Herz- und Lungenerkrankungen, hormonellen Störungen oder als unerwünschte Nebenwirkungen von Medikamenten auf.
Ashwagandha (Withania somnifera)
Authors: Siddique Anwar
Published: April 2024

Ashwagandha ist Sanskrit und bedeutet „Pferdegeruch“. Der wissenschaftliche Name dieser Pflanze ist Withania somnifera. Sie gehört zur Familie der Nachtschattengewächse (Solanaceae), wie Kartoffel, Aubergine, Tomate, Bittersüßer Nachtschatten (Solanum dulcamara) und Tollkirsche (Atropa belladonna). Bei uns wird Ashwagandha auch Indischer Ginseng, Schlafbeere oder winter cherry genannt.