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1.
Mol Cell ; 79(2): 320-331.e9, 2020 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-32645369

RESUMEN

Valosin-containing protein (VCP)/p97 is an AAA-ATPase that extracts polyubiquitinated substrates from multimeric macromolecular complexes and biological membranes for proteasomal degradation. During p97-mediated extraction, the substrate is largely deubiquitinated as it is threaded through the p97 central pore. How p97-extracted substrates are targeted to the proteasome with few or no ubiquitins is unknown. Here, we report that p97-extracted membrane proteins undergo a second round of ubiquitination catalyzed by the cytosolic ubiquitin ligase RNF126. RNF126 interacts with transmembrane-domain-specific chaperone BAG6, which captures p97-liberated substrates. RNF126 depletion in cells diminishes the ubiquitination of extracted membrane proteins, slows down their turnover, and dramatically stabilizes otherwise transient intermediates in the cytosol. We reconstitute the reubiquitination of a p97-extracted, misfolded multispanning membrane protein with purified factors. Our results demonstrate that p97-extracted substrates need to rapidly engage ubiquitin ligase-chaperone pairs that rebuild the ubiquitin signal for proteasome targeting to prevent harmful accumulation of unfolded intermediates.


Asunto(s)
Proteínas de la Membrana/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteína que Contiene Valosina/metabolismo , Catálisis , Citosol/metabolismo , Células HEK293 , Humanos , Chaperonas Moleculares/metabolismo , Pliegue de Proteína , Proteolisis , Solubilidad , Ubiquitinación
2.
Anal Chem ; 96(18): 7091-7100, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38663871

RESUMEN

Detection of intracellular miRNAs, especially sensitive imaging of in vivo miRNAs, is vital to the precise prediction and timely prevention of tumorgenesis but remains a technical challenge in terms of nuclease resistance and signal amplification. Here, we demonstrate a gold nanoparticle-based spherical nucleic acid-mediated spatial matching-guided nonenzymatic DNA circuit (SSDC) for efficient screening of intracellular miRNAs and, in turn, finding cancerous tissues in living organisms before the appearance of clinical symptoms. Due to the substantially enhanced nuclease resistance, the false positive signal is avoided even in a complex biological medium. Target miRNA can straighten out the hairpin DNA probe to be linear, allowing the probe to penetrate into the internal region of a core/shell DNA-functionalized signal nanoampfilier and initiate a strand displacement reaction, generating an amplified fluorescence signal. The detection limit is as low as 17 pM, and miRNA imaging is in good accordance with the gold standard polymerase chain reaction method. The ability to image intracellular miRNAs is substantially superior to that of conventional fluorescence in situ hybridization techniques, making in vivo SSDC-based imaging competent for the precise prediction of tumorigenesis. By intratumoral chemotherapy guided by SSDC-based imaging, tumorigenesis and progression are efficiently controlled before the onset of clinical symptoms.


Asunto(s)
Oro , Nanopartículas del Metal , MicroARNs , Humanos , MicroARNs/análisis , Oro/química , Nanopartículas del Metal/química , Animales , Invasividad Neoplásica , ADN/química , Ratones , Neoplasias , Sondas de ADN/química
3.
Small ; : e2306257, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38377302

RESUMEN

Due to the disadvantages of poor targeting, slow action, and low effectiveness of current commonly used cancer treatments, including surgery, chemotherapy, and radiotherapy, researchers have turned to DNA as a biomaterial for constructing drug delivery nanocarriers. DNA is favored for its biocompatibility and programmability. In order to overcome the limitations associated with traditional drug delivery systems (DDSs), researchers have developed smart-responsive DNA DDSs that can control drug release in response to specific physical or chemical stimuli at targeted sites. In this review, a summary of multiple targeted ligand structures is provided, various shapes of stable DNA nanomaterials, and different stimuli-responsive drug release strategies in DNA DDSs. Specifically, targeted cell recognition, in vivo stable transport, and controlled drug release of smart DDSs are focused. Finally, the further development prospects and challenges of clinical application of DNA nanomaterials in the field of smart drug delivery are discussed. The objective of this review is to enhance researchers' comprehension regarding the potential application of DNA nanomaterials in precision drug delivery, with the aim of expediting the clinical implementation of intelligent DDSs.

4.
Chembiochem ; : e202400328, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38742991

RESUMEN

Baeyer-Villiger monooxygenases belong to a family of flavin-binding proteins that catalyze the Baeyer-Villiger (BV) oxidation of ketones to produce lactones or esters, which are important intermediates in pharmaceuticals or sustainable materials. Phenylacetone monooxygenase (PAMO) from Thermobifida fusca with moderate thermostability catalyzes the oxidation of aryl ketone substrates, but is limited by high specificity and narrow substrate scope. In the present study, we applied loop optimization by loop swapping followed by focused saturation mutagenesis in order to evolve PAMO mutants capable of catalyzing the regioselective BV oxidation of cyclohexanone and cyclobutanone derivatives with formation of either normal or abnormal esters or lactones. We further modulated PAMO to increase enantioselectivity. Crystal structure studies indicate that rotation occurs in the NADP-binding domain and that the high B-factor region is predominantly distributed in the catalytic pocket residues. Computational analyses further revealed dynamic character in the catalytic pocket and reshaped hydrogen bond interaction networks, which is more favorable for substrate binding. Our study provides useful insights for studying enzyme-substrate adaptations.

5.
Chembiochem ; 25(9): e202400069, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38504591

RESUMEN

Arylalkylamine N-acetyltransferase (AANAT) serves as a key enzyme in the biosynthesis of melatonin by transforming 5-hydroxytryptamine (5-HT) to N-acetyl-5-hydroxytryptamine (NAS), while its low activity may hinder melatonin yield. In this study, a novel AANAT derived from Sus scrofa (SsAANAT) was identified through data mining using 5-HT as a model substrate, and a rational design of SsAANAT was conducted in the quest to improving its activity. After four rounds of mutagenesis procedures, a triple combinatorial dominant mutant M3 was successfully obtained. Compared to the parent enzyme, the conversion of the whole-cell reaction bearing the best variant M3 exhibted an increase from 50 % to 99 % in the transformation of 5-HT into NAS. Additionally, its catalytic efficiency (kcat/Km) was enhanced by 2-fold while retaining the thermostability (Tm>45 °C). In the up-scaled reaction with a substrate loading of 50 mM, the whole-cell system incorporating variant M3 achieved a 99 % conversion of 5-HT in 30 h with an 80 % yield. Molecular dynamics simulations were ultilized to shed light on the origin of improved activity. This study broadens the repertoire of AANAT for the efficient biosynthesis of melatonin.


Asunto(s)
N-Acetiltransferasa de Arilalquilamina , Serotonina , N-Acetiltransferasa de Arilalquilamina/metabolismo , N-Acetiltransferasa de Arilalquilamina/genética , N-Acetiltransferasa de Arilalquilamina/química , Serotonina/metabolismo , Serotonina/química , Serotonina/biosíntesis , Animales , Acetilación , Ingeniería de Proteínas , Porcinos
6.
Int Microbiol ; 27(1): 277-290, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37316617

RESUMEN

BACKGROUND: Polymyxin B is considered a last-line therapeutic option against multidrug-resistant gram-negative bacteria, especially in COVID-19 coinfections or other serious infections. However, the risk of antimicrobial resistance and its spread to the environment should be brought to the forefront. METHODS: Pandoraea pnomenusa M202 was isolated under selection with 8 mg/L polymyxin B from hospital sewage and then was sequenced by the PacBio RS II and Illumina HiSeq 4000 platforms. Mating experiments were performed to evaluate the transfer of the major facilitator superfamily (MFS) transporter in genomic islands (GIs) to Escherichia coli 25DN. The recombinant E. coli strain Mrc-3 harboring MFS transporter encoding gene FKQ53_RS21695 was also constructed. The influence of efflux pump inhibitors (EPIs) on MICs was determined. The mechanism of polymyxin B excretion mediated by FKQ53_RS21695 was investigated by Discovery Studio 2.0 based on homology modeling. RESULTS: The MIC of polymyxin B for the multidrug-resistant bacterial strain P. pnomenusa M202, isolated from hospital sewage, was 96 mg/L. GI-M202a, harboring an MFS transporter-encoding gene and conjugative transfer protein-encoding genes of the type IV secretion system, was identified in P. pnomenusa M202. The mating experiment between M202 and E. coli 25DN reflected the transferability of polymyxin B resistance via GI-M202a. EPI and heterogeneous expression assays also suggested that the MFS transporter gene FKQ53_RS21695 in GI-M202a was responsible for polymyxin B resistance. Molecular docking revealed that the polymyxin B fatty acyl group inserts into the hydrophobic region of the transmembrane core with Pi-alkyl and unfavorable bump interactions, and then polymyxin B rotates around Tyr43 to externally display the peptide group during the efflux process, accompanied by an inward-to-outward conformational change in the MFS transporter. Additionally, verapamil and CCCP exhibited significant inhibition via competition for binding sites. CONCLUSIONS: These findings demonstrated that GI-M202a along with the MFS transporter FKQ53_RS21695 in P. pnomenusa M202 could mediate the transmission of polymyxin B resistance.


Asunto(s)
Burkholderiaceae , Escherichia coli , Polimixina B , Polimixina B/farmacología , Escherichia coli/genética , Islas Genómicas , Simulación del Acoplamiento Molecular , Aguas del Alcantarillado , Proteínas de Transporte de Membrana/genética , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana
7.
Environ Res ; 245: 117901, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38092235

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) are significant petroleum pollutants that have long-term impacts on human health and ecosystems. However, assessing their toxicity presents challenges due to factors such as cost, time, and the need for comprehensive multi-component analysis methods. In this study, we utilized network toxicity models, enrichment analysis, and molecular docking to analyze the toxicity mechanisms of PAHs at different levels: compounds, target genes, pathways, and species. Additionally, we used the maximum acceptable concentration (MAC) value and risk quotient (RQ) as an indicator for the potential ecological risk assessment of PAHs. The results showed that higher molecular weight PAHs had increased lipophilicity and higher toxicity. Benzo[a]pyrene and Fluoranthene were identified as core compounds, which increased the risk of cancer by affecting core target genes such as CCND1 in the human body, thereby influencing signal transduction and the immune system. In terms of biological species, PAHs had a greater toxic impact on aquatic organisms compared to terrestrial organisms. High molecular weight PAHs had lower effective concentrations on biological species, and the ecological risk was higher in the Yellow River Delta region. This research highlights the potential application of network toxicity models in understanding the toxicity mechanisms and species toxicity of PAHs and provides valuable insights for monitoring, prevention, and ecological risk assessment of these pollutants.


Asunto(s)
Contaminantes Ambientales , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Humanos , Hidrocarburos Policíclicos Aromáticos/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Ecosistema , Contaminantes Ambientales/toxicidad , Contaminantes Ambientales/análisis , Petróleo/toxicidad , Petróleo/análisis , Simulación del Acoplamiento Molecular , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Medición de Riesgo , China , Sedimentos Geológicos/análisis
8.
J Appl Toxicol ; 44(2): 152-164, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37655586

RESUMEN

Nano-titanium dioxide (TiO2 NPs) is widely used for its extremely high stability, corrosion resistance, and photocatalytic properties and has penetrated into various fields of production and life. Assessing its toxicity to different organs should be a key part of preclinical toxicity assessment of TiO2 NPs, which is relatively incomprehensive yet. Therefore, this review focuses on the toxic effects of TiO2 NPs on various organs in mammals and biological mechanisms from different organs. The commonality of toxic effects on various target organs reflected in tissue structure damage and dysfunction, such as liver damage and dysfunction; pulmonary fibrosis; and renal impairment (including hematuria and nephritis); damage of brain tissue and neurons; alteration of intestinal villi; and weight loss. And effects on the reproductive system are affected by different sexes, including ovarian dysfunction, testicular development damage, and sperm viability reduction. We believe that the toxic mechanisms of TiO2 NPs in target organs have commonalities, such as oxidative stress, inflammatory responses, and organelle damage. However, different target organ toxicities also have their specificities. TiO2 NPs disturb the intestinal flora and cause undesirable changes in feces products. And in spleen are infiltration of neutrophils and lymphadenopathy and eventually immune deficiency. Although the toxic pathways are different, but there may be a close link between the different toxic pathways. In this article, the main manifestations of the toxic effects of titanium dioxide nanoparticles on major mammalian organs are reviewed, in order to provide basic data for their better application from a medical perspective.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Animales , Masculino , Semen , Estrés Oxidativo , Nanopartículas/toxicidad , Titanio/toxicidad , Titanio/química , Nanopartículas del Metal/toxicidad , Mamíferos
9.
Artículo en Inglés | MEDLINE | ID: mdl-38734936

RESUMEN

Rheumatoid arthritis (RA) is an idiopathic and chronic autoimmune disease for which there are currently no effective treatments. Oxypeucedanin hydrate (OXH) is a natural coumarin known for its potent anti-inflammatory properties. However, further investigations are needed to determine its therapeutic efficacy in treating RA. In this study, we evaluate the anti-inflammatory activity of OXH by treating LPS-induced RAW264.7 macrophages. Our results show that OXH treatment reverses the changes in iNOS, COX-2, IL-1ß, IL-6, and TNF-α levels. Additionally, OXH reduces ROS production. Further analysis reveals that OXH suppresses the activation of the NF-κB/MAPK pathway. CETSA results show that OXH competes with LPS for binding to the TLR4/MD2 complex. MST experiments demonstrate the specific affinity of OXH for the TLR4/MD2 complex, with a Kd value of 33.7 µM. Molecular docking analysis suggests that OXH binds to the pocket of the TLR4/MD2 complex and interacts with specific amino acids, such as GLY-343, LYS-388, and PHE-345. Molecular dynamics simulations further confirm this conclusion. Finally, we investigate the potential of OXH in treating RA using a collagen-induced arthritis (CIA) model in rats. OXH effectively ameliorates the symptoms of CIA, including improving body weight, reducing swelling and redness, increasing talus volume, and decreasing bone erosion. OXH also decreases the mRNA levels of pro-inflammatory factors in synovial tissue. Transcriptome enrichment analysis and western blot analysis confirm that OXH suppresses the NF-κB/MAPK pathway, which is consistent with our in vitro findings.

10.
Proc Natl Acad Sci U S A ; 118(6)2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33526684

RESUMEN

Spin-momentum locking, a manifestation of topological properties that governs the behavior of surface states, was studied intensively in condensed-matter physics and optics, resulting in the discovery of topological insulators and related effects and their photonic counterparts. In addition to spin, optical waves may have complex structure of vector fields associated with orbital angular momentum or nonuniform intensity variations. Here, we derive a set of spin-momentum equations which describes the relationship between the spin and orbital properties of arbitrary complex electromagnetic guided modes. The predicted photonic spin dynamics is experimentally verified with four kinds of nondiffracting surface structured waves. In contrast to the one-dimensional uniform spin of a guided plane wave, a two-dimensional chiral spin swirl is observed for structured guided modes. The proposed framework opens up opportunities for designing the spin structure and topological properties of electromagnetic waves with practical importance in spin optics, topological photonics, metrology and quantum technologies and may be used to extend the spin-dynamics concepts to fluid, acoustic, and gravitational waves.

11.
Chem Biodivers ; : e202401093, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38867371

RESUMEN

Two previously undescribed coumarins (1-2) were isolated from the root of Notopterygium incisum. The structures of new findings were elucidated by analyses of spectral evidences in HRESIMS, NMR, as well as ICD. The absolute configurations were further confirmed by chemical calculations. 1-2 exhibits obviously anti-inflammatory activity by inhibiting the expression of inflammatory mediators (COX-2, iNOS), as well as reducing the release of NO and the accumulation of ROS in cells. Western blotting analysis revealed that 2 could inhibit the PI3K/AKT pathway by reducing the expression of p-PI3K and p-AKT.

12.
Environ Toxicol ; 39(3): 1388-1401, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37986241

RESUMEN

Silver is usually loaded on nano-titanium dioxide (TiO2 ) through photodeposition method to enhance visible-light catalytic functions for environment purification. However, little is known about how the toxicity changes after silver doping and how the physicochemical properties of loaded components affect nanocomposite toxicity. In this study, Ag-TiO2 with different sizes and contents of silver particles were obtained by controlling photodeposition time (PDT) and silver addition amount. Pro-inflammatory and pro-fibrogenic responses of these photocatalysts were evaluated in male C57BL/6J murine lung. As a result, silver was well assembled on TiO2 , promoting visible-light catalytic activity. Notably, the size of silver particles increased with PDT. Meanwhile, toxicity results showed that pure TiO2 (P25) mainly caused neutrophil infiltration, while 2 wt/wt% silver-loaded TiO2 recruited more types of inflammatory cells in the lung. Both of them caused the increase of proinflammatory cytokines while decreasing the anti-inflammatory cytokine in bronchoalveolar lavage fluid. However, 2 wt/wt% silver doping also accelerated the lung pro-fibrogenic response of photocatalysts in the subacute phase from evidence of collagen deposition and hydroxyproline concentrations. Mechanistically, the overactivation of TGFBR2 receptors in TGF-ß/smads pathways by silver-loaded TiO2 rather than pure TiO2 may be the reason why silver-loaded TiO2 can promote pro-fibrogenic effect response. Intriguingly, the increased toxicity caused by silver doping can be rescued by increasing the size of the loaded silver or decreasing the silver amount. These results may be important for the new understanding of the toxicity of TiO2 -based photocatalysts.


Asunto(s)
Nanopartículas del Metal , Plata , Ratones , Masculino , Animales , Plata/química , Nanopartículas del Metal/química , Pulmón , Líquido del Lavado Bronquioalveolar , Titanio/química , Citocinas
13.
J Environ Manage ; 360: 121137, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38796874

RESUMEN

Understanding the relationship between hydrological connectivity (HC) and water level (WL) is crucial for effective water resource management and wetland restoration. However, current knowledge regarding this relationship is limited. This study proposed an integrated nonstationary and uncertain analysis framework (INUAF) to investigate the HC-WL relationship with reference to the Baiyangdian wetland, which is a fragmented wetland in North China. With the INUAF, the interannual and intra-annual variations of both HC and WL were examined, together with the wavelet coherence and lag effects between the two variables at multiple scales. The results highlighted marked nonstationarity in HC, WL, and the relationship between them. Scale-dependent lag effects revealed that HC lags WL by 37 days (131 days) at the 1 a scale (4 a scale), and leads WL by 190 days at the 8 a scale, indicating a complex coupled relationship between HC and WL. Additionally, the INUAF was applied to evaluating the uncertainty in the response of lagged HC to varied WL. Results indicated that every 0.2-m increase in WL led to a 2.2%-2.4% higher probability of maintaining high HC for WL between 6.0 and 8.0 m, but a 10%-11% higher probability for WL between 8.0 and 9.0 m. We suggest that a WL of > 8.4 m would produce a probability of > 50% for achieving high HC. These findings provide valuable insights into the HC-WL relationship and could contribute to wetland restoration efforts.


Asunto(s)
Hidrología , Humedales , China , Incertidumbre , Agua
14.
Angew Chem Int Ed Engl ; 63(12): e202319913, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38284290

RESUMEN

Authentic surface structures under reaction conditions determine the activity and selectivity of electrocatalysts, therefore, the knowledge of the structure-activity relationship can facilitate the design of efficient catalyst structures for specific reactivity requirements. However, understanding the relationship between a more realistic active surface and its performance is challenging due to the complicated interface microenvironment in electrocatalysis. Herein, we proposed a standard research paradigm to effectively decipher the structure-activity relationship in electrocatalysis, which is exemplified in the CO2 electroreduction over SnO2 . The proposed practice has aided in discovering authentic/resting surface states (Sn layer) of SnO2 accountable for the electrochemical CO2 reduction reaction (CO2 RR) performance under electrocatalytic conditions, which then is corroborated in the subsequent CO2 RR experiments over SnO2 with different morphologies (nanorods, nanoparticles, and nanosheets) in combination with in situ characterizations. This proposed methodology is further extended to the SnO electrocatalysts, providing helpful insights into catalytic structures. It is believed that our proposed standard research paradigm is also applicable to other electrocatalytic systems, in the meantime, decreases the discrepancy between theory and experiments, and accelerates the design of catalyst structures that achieve sustainable performance for energy conversion.

15.
BMC Microbiol ; 23(1): 134, 2023 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-37193944

RESUMEN

BACKGROUND: Arsenic (As) with various chemical forms, including inorganic arsenic and organic arsenic, is the most prevalent water and environmental toxin. This metalloid occurs worldwide and many of its forms, especially arsenite [As(III)], cause various diseases including cancer. Organification of arsenite is an effective way for organisms to cope with arsenic toxicity. Microbial communities are vital contributors to the global arsenic biocycle and represent a promising way to reduce arsenite toxicity. METHODS: Brevundimonas sp. M20 with arsenite and roxarsone resistance was isolated from aquaculture sewage. The arsHRNBC cluster and the metRFHH operon of M20 were identified by sequencing. The gene encoding ArsR/methyltransferase fusion protein, arsRM, was amplified and expressed in Escherichia coli BL21 (DE3), and this strain showed resistance to arsenic in the present of 0.25-6 mM As(III), aresenate, or pentavalent roxarsone. The methylation activity and regulatory action of ArsRM were analyzed using Discovery Studio 2.0, and its functions were confirmed by methyltransferase activity analysis and electrophoretic mobility shift assays. RESULTS: The minimum inhibitory concentration of the roxarsone resistant strain Brevundimonas sp. M20 to arsenite was 4.5 mM. A 3,011-bp arsenite resistance ars cluster arsHRNBC and a 5649-bp methionine biosynthesis met operon were found on the 3.315-Mb chromosome. Functional prediction analyses suggested that ArsRM is a difunctional protein with transcriptional regulation and methyltransferase activities. Expression of ArsRM in E. coli increased its arsenite resistance to 1.5 mM. The arsenite methylation activity of ArsRM and its ability to bind to its own gene promoter were confirmed. The As(III)-binding site (ABS) and S-adenosylmethionine-binding motif are responsible for the difunctional characteristic of ArsRM. CONCLUSIONS: We conclude that ArsRM promotes arsenite methylation and is able to bind to its own promoter region to regulate transcription. This difunctional characteristic directly connects methionine and arsenic metabolism. Our findings contribute important new knowledge about microbial arsenic resistance and detoxification. Future work should further explore how ArsRM regulates the met operon and the ars cluster.


Asunto(s)
Arsénico , Arsenicales , Arsenitos , Roxarsona , Arsénico/metabolismo , Arsenitos/farmacología , Arsenitos/metabolismo , Secuencia de Bases , Escherichia coli/genética , Escherichia coli/metabolismo , Metilación , Roxarsona/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Arsenicales/metabolismo , Arsenicales/farmacología , Operón , Metiltransferasas/genética , Metionina , Regulación Bacteriana de la Expresión Génica , Transactivadores/genética
16.
Phys Chem Chem Phys ; 25(39): 26906-26916, 2023 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-37786394

RESUMEN

Sodium-rich anti-perovskites have unique advantages in terms of composition tuning and electrochemical stability when used as solid-state electrolytes in sodium-ion batteries. However, their Na+ transport mechanism is not clear and Na+ conductivity needs to be improved. In this paper, we investigate the stability, elastic properties and Na+ transport mechanisms of both the double anti-perovskite Na3S0.5O0.5I and anti-perovskite Na3OI. The results indicate that the NaI Schottky defect is the most favorable intrinsic defect for Na+ transport and due to the substitution of S2- for O2-, Na3S0.5O0.5I has stronger ductility and higher Na+ conductivity compared to Na3OI, despite the electrochemical window being slightly narrower. Divalent alkaline earth metal dopants can increase the Na+ vacancy concentration, while impeding Na+ migration. Among the dopants, Sr2+ and Ca2+ are the optimal dopants for Na3S0.5O0.5I and Na3OI, respectively. Notably, the Na+ conductivity of the non-stoichiometric Na3S0.5O0.5I at room temperature is 1.2 × 10-3 S cm-1, indicating its great potential as a solid-state electrolyte. Moreover, strain effect calculations show that biaxial tensile strain is beneficial for Na+ transport. Our work reveals the sodium-ion transport mechanism and elastic properties of double anti-perovskites, which is of great significance for the development of solid-state electrolytes.

17.
Phytopathology ; 113(5): 858-865, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-35906768

RESUMEN

Gummy stem blight (GSB), caused by Didymella bryoniae, is a devastating fungal disease of melon worldwide. Breeding GSB-resistant cultivars with host resistance genes is considered the most economic and effective strategy to control this disease. In this study, 260 melon germplasm resources were screened for resistance to GSB, and an inbred line, H55R, that exhibited immunity to GSB was identified. To further understand the resistance mechanism of H55R against GSB, an F2 population was obtained from a cross between the GSB-susceptible line A15 and H55R, and genetic analysis indicated that the GSB resistance in H55R was controlled by a single dominant gene, tentatively named Gsb-7(t). The Gsb-7(t) gene was finally delimited to a 140-kb interval on chromosome 7 using bulked segregant analysis and chromosome walking strategies. Ten putative genes were annotated in this region that contains a wall-associated receptor kinase (WAK) gene MELO3C010403. The MELO3C010403 gene contains two alternative transcripts, MELO3C010403-T1 and MELO3C010403-T2, with five and seven nonsynonymous mutation sites, respectively. Gene expression analysis showed that expression of MELO3C010403-T2 but not MELO3C010403-T1 was significantly induced by D. bryoniae at 24 h postinoculation, indicating that the MELO3C010403-T2 transcript of MELO3C010403 was the most likely candidate gene of Gsb-7(t). Our results offer new genetic resources and will be helpful for the development of GSB-resistant melon cultivars in the future.


Asunto(s)
Cucurbitaceae , Cucurbitaceae/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Fitomejoramiento , Resistencia a la Enfermedad/genética
18.
J Chem Phys ; 159(2)2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37428063

RESUMEN

Due to high ion conductivity, low cost, and adjustable composition, antiperovskite has attracted much attention as a potentially useful material in solid-state batteries. Compared with simple antiperovskite, Ruddlesden-Popper (R-P) antiperovskite is an updated material, which is not only more stable but also reported to significantly enhance conductivity when added to simple antiperovskite. However, systematic theoretical research on R-P antiperovskite is scarce, hindering its further development. In this study, the recently reported easily synthesized R-P antiperovskite LiBr(Li2OHBr)2 is calculated for the first time. Comparative calculations were conducted on the transport performance, thermodynamic properties, and mechanical properties of H-rich LiBr(Li2OHBr)2 and H-free LiBr(Li3OBr)2. Our results indicate that due to the presence of protons, LiBr(Li2OHBr)2 is more prone to defects, and synthesizing more LiBr Schottky defects can improve its Li-ion conductivity. Young's modulus of the LiBr(Li2OHBr)2 is as low as 30.61 GPa, which is beneficial for its application as a sintering aid. However, the calculated Pugh's ratio (B/G) of 1.28 and 1.50, respectively, indicates that R-P antiperovskites LiBr(Li2OHBr)2 and LiBr(Li3OBr)2 exhibit mechanical brittleness, which is not conducive to its application as solid electrolytes. Through quasi-harmonic approximation, we found that the linear thermal expansion coefficient of LiBr(Li2OHBr)2 is 2.07 × 10-5 K-1, which is more advantageous in matching electrodes than LiBr(Li3OBr)2 and even simple antiperovskites. Overall, our research provides comprehensive insights into the practical application of R-P antiperovskite in solid-state batteries.

19.
Gen Physiol Biophys ; 42(4): 385, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37449323

RESUMEN

The article "The circRNA-MYLK plays oncogenic roles in the Hep-2 cell line by sponging microRNA-145-5p" by Yao Chen, Yanmei Wang, Congcong Li, Xuechang Li, Tiejun Yuan, Shuqin Yang and Xiaoyan Sun, published in Gen. Physiol. Biophys. 39(3), 2020, pp. 229-237 (doi: 10.4149/gpb_2019060) has been retracted by agreement between the author(s) and journal's Editor in Chief, Prof. Dr. Lubica Lacinova, and AEPresss, s.r.o.. The corresponding author Xiaoyan Sun asked to retract this manuscript as there were some substantial problems in it, which needed more time and research to solve and can more fully re-examine and revise his research results.The authors were not available for a final confirmation of the retraction.

20.
Neuroimage ; 259: 119420, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-35777634

RESUMEN

Multimodal neuroimaging plays an important role in neuroscience research. Integrated noninvasive neuroimaging modalities, such as magnetoencephalography (MEG), electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), allow neural activity and related physiological processes in the brain to be precisely and comprehensively depicted, providing an effective and advanced platform to study brain function. Noncryogenic optically pumped magnetometer (OPM) MEG has high signal power due to its on-scalp sensor layout and enables more flexible configurations than traditional commercial superconducting MEG. Here, we integrate OPM-MEG with EEG and fNIRS to develop a multimodal neuroimaging system that can simultaneously measure brain electrophysiology and hemodynamics. We conducted a series of experiments to demonstrate the feasibility and robustness of our MEG-EEG-fNIRS acquisition system. The complementary neural and physiological signals simultaneously collected by our multimodal imaging system provide opportunities for a wide range of potential applications in neurovascular coupling, wearable neuroimaging, hyperscanning and brain-computer interfaces.


Asunto(s)
Interfaces Cerebro-Computador , Magnetoencefalografía , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Electroencefalografía , Humanos , Magnetoencefalografía/métodos , Neuroimagen
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