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1.
Proc Natl Acad Sci U S A ; 121(28): e2322972121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38968116

ABSTRACT

Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.


Subject(s)
DNA Repair , Ubiquitin-Protein Ligases , Humans , DNA Breaks, Double-Stranded , Histones/metabolism , Histones/genetics , Polyubiquitin/metabolism , Tumor Suppressor p53-Binding Protein 1/metabolism , Tumor Suppressor p53-Binding Protein 1/genetics , Ubiquitin/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitination
2.
Nucleic Acids Res ; 51(18): 9733-9747, 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37638744

ABSTRACT

RAP80 has been characterized as a component of the BRCA1-A complex and is responsible for the recruitment of BRCA1 to DNA double-strand breaks (DSBs). However, we and others found that the recruitment of RAP80 and BRCA1 were not absolutely temporally synchronized, indicating that other mechanisms, apart from physical interaction, might be implicated. Recently, liquid-liquid phase separation (LLPS) has been characterized as a novel mechanism for the organization of key signaling molecules to drive their particular cellular functions. Here, we characterized that RAP80 LLPS at DSB was required for RAP80-mediated BRCA1 recruitment. Both cellular and in vitro experiments showed that RAP80 phase separated at DSB, which was ascribed to a highly disordered region (IDR) at its N-terminal. Meanwhile, the Lys63-linked poly-ubiquitin chains that quickly formed after DSBs occur, strongly enhanced RAP80 phase separation and were responsible for the induction of RAP80 condensation at the DSB site. Most importantly, abolishing the condensation of RAP80 significantly suppressed the formation of BRCA1 foci, encovering a pivotal role of RAP80 condensates in BRCA1 recruitment and radiosensitivity. Together, our study disclosed a new mechanism underlying RAP80-mediated BRCA1 recruitment, which provided new insight into the role of phase separation in DSB repair.

3.
Nano Lett ; 24(14): 4082-4090, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38526914

ABSTRACT

The generally nonpolar SrTiO3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO3/SrTiO3/PbTiO3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 µC/cm2). These values are nearly comparable to those of the strong ferroelectrics as the PbZrxTi1-xO3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

4.
Nano Lett ; 24(37): 11714-11721, 2024 Sep 18.
Article in English | MEDLINE | ID: mdl-39240781

ABSTRACT

Antiferroelectric materials have shown great potential in electronic devices benefiting from the reversible phase transition between ferroelectric and antiferroelectric phases. Understanding the dipole arrangements and clear phase transition pathways is crucial for design of antiferroelectric materials-based energy storage and conversion devices. However, the specific phase transition details remain largely unclear and even controversial to date. Here, we have grown a series of PbZrO3 on SrTiO3 substrates and elucidated the fine atom structures and phase transition pathways using atomic-resolution transmission electron microscopy. Specifically, a roadmap for ferroelectric to antiferroelectric phase transitions, here with increasing film thickness, is determined as ferroelectric rhombohedral (R3c)-ferroelectric monoclinic (Pc)-ferrielectric orthorhombic (Ima2)-antiferroelectric orthorhombic (Pbam), where Pc and Ima2 phases act as structural bridges. Moreover, the phase transition pathway is strongly related to the synergistic effect of oxygen octahedral tilting and cation displacement. These findings provide an insightful understanding for the theories and related properties of antiferroelectrics.

5.
J Cell Sci ; 135(7)2022 04 01.
Article in English | MEDLINE | ID: mdl-35297486

ABSTRACT

Vascular intimal injury initiates various cardiovascular disease processes. Exposure to subendothelial collagen can cause platelet activation, leading to collagen-activated platelet-derived microvesicles (aPMVs) secretion. In addition, vascular smooth muscle cells (VSMCs) exposed to large amounts of aPMVs undergo abnormal energy metabolism; they proliferate excessively and migrate after the loss of endothelium, eventually contributing to neointimal hyperplasia. However, the roles of aPMVs in VSMC energy metabolism are still unknown. Our carotid artery intimal injury model indicated that platelets adhered to injured blood vessels. In vitro, phosphorylated Pka (cAMP-dependent protein kinase) content was increased in aPMVs. We also found that aPMVs significantly reduced VSMC glycolysis and increased oxidative phosphorylation, and promoted VSMC migration and proliferation by upregulating phosphorylated PRKAA (α catalytic subunit of AMP-activated protein kinase) and phosphorylated FoxO1. Compound C, an inhibitor of PRKAA, effectively reversed the enhancement of cellular function and energy metabolism triggered by aPMVs in vitro and neointimal formation in vivo. We show that aPMVs can affect VSMC energy metabolism through the Pka-PRKAA-FoxO1 signaling pathway and this ultimately affects VSMC function, indicating that the shift in VSMC metabolic phenotype by aPMVs can be considered a potential target for the inhibition of hyperplasia. This provides a new perspective for regulating the abnormal activity of VSMCs after injury.


Subject(s)
Carotid Artery Injuries , Muscle, Smooth, Vascular , AMP-Activated Protein Kinases/metabolism , Animals , Blood Platelets/metabolism , Carotid Artery Injuries/genetics , Carotid Artery Injuries/metabolism , Cell Movement , Cell Proliferation , Cells, Cultured , Cyclic AMP-Dependent Protein Kinases/metabolism , Disease Models, Animal , Energy Metabolism , Humans , Hyperplasia/complications , Hyperplasia/metabolism , Hyperplasia/pathology , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Neointima/complications , Neointima/metabolism , Neointima/pathology
6.
Clin Exp Immunol ; 2024 Sep 09.
Article in English | MEDLINE | ID: mdl-39248363

ABSTRACT

Amlexanox (ALX) is a small molecule drug for the treatment of inflammatory, autoimmune, metabolic and tumor diseases. At present, there are no studies on whether ALX has a therapeutic effect on inflammatory bowel disease (IBD). In this study, we used a mouse model of dextran sulfate sodium (DSS)-induced colitis to investigate the effect of ALX targeted inhibition of TBK1 on colitis. We found that the severity of colitis in mice was correlated with TBK1 expression. Notably, although ALX inhibited the activation of the TBK1-NF-κB/TBK1-IRF3 pro-inflammatory signaling pathway, it exacerbated colitis and reduced survival in mice. The results of drug safety experiments ruled out a relationship between this exacerbating effect and drug toxicity. In addition, ELISA results showed that ALX promoted the secretion of IL-1ß and IFN-α, and inhibited the production of cytokines IL-6, TNF-α, IL-10, TGF-ß and secretory IgA. Flow cytometry results further showed that ALX promoted T cell proliferation, activation and differentiation, and thus played a pro-inflammatory role; Also, ALX inhibited the generation of dendritic cells and the polarization of macrophages to M1 type, thus exerting anti-inflammatory effect. These data suggest that the regulation of ALX on the function of different immune cells is different, so the effect on the inflammatory response is bidirectional. In conclusion, our study demonstrates that simply inhibiting TBK1 in all immune cells is not effective for the treatment of colitis. Further investigation the anti-inflammatory mechanism of ALX on dendritic cells and macrophages may provide a new strategy for the treatment of IBD.

7.
Microb Pathog ; 196: 106879, 2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39218372

ABSTRACT

Epinecidin-1 (Epi-1) is an antimicrobial peptide originated from fish with various pharmacological activities but carries the risk of acquiring resistance with long-term use. In the present study, we use L-lactic acid to enhance the antibacterial activity of synthesized Epi-1 against the aquaculture and food pathogen Aeromonas hydrophila. The results showed that 5.5 mmol/L lactic acid increased the inhibitory and bactericidal activity of 25 µmol/L Epi-1 against two strains of A. hydrophila. The laser confocal images proved that lactic acid pre-treatment improved the attachment efficiency of Epi-1 in A.hydrophila cells. In addition, lactic acid enhanced the damaging effect of Epi-1 on the cell membrane of A. hydrophila, evidenced by releasing more nucleic acids, proteins, and transmembrane pH ingredients decrease and electromotive force dissipation. SEM images showed that compared with the single Epi-1 treatment, the co-treatment of Epi-1 and lactic acid caused more outer membrane vesicles (OMVs) and more severe cell deformation. These findings proved that lactic acid could enhance the efficiency of Epi-1 against A. hydrophila and shed light on new aspects to avoid resistance of pathogens against Epi-1.

8.
Plant Cell ; 33(4): 846-864, 2021 05 31.
Article in English | MEDLINE | ID: mdl-33630094

ABSTRACT

The grass family (Poaceae) includes all commercial cereal crops and is a major contributor to biomass in various terrestrial ecosystems. The ancestry of all grass genomes includes a shared whole-genome duplication (WGD), named rho (ρ) WGD, but the evolutionary significance of ρ-WGD remains elusive. We sequenced the genome of Pharus latifolius, a grass species (producing a true spikelet) in the subfamily Pharoideae, a sister lineage to the core Poaceae including the (Panicoideae, Arundinoideae, Chloridoideae, Micrairoideae, Aristidoideae, and Danthonioideae (PACMAD) and Bambusoideae, Oryzoideae, and Pooideae (BOP) clades. Our results indicate that the P. latifolius genome has evolved slowly relative to cereal grass genomes, as reflected by moderate rates of molecular evolution, limited chromosome rearrangements and a low rate of gene loss for duplicated genes. We show that the ρ-WGD event occurred approximately 98.2 million years ago (Ma) in a common ancestor of the Pharoideae and the PACMAD and BOP grasses. This was followed by contrasting patterns of diploidization in the Pharus and core Poaceae lineages. The presence of two FRIZZY PANICLE-like genes in P. latifolius, and duplicated MADS-box genes, support the hypothesis that the ρ-WGD may have played a role in the origin and functional diversification of the spikelet, an adaptation in grasses related directly to cereal yields. The P. latifolius genome sheds light on the origin and early evolution of grasses underpinning the biology and breeding of cereals.


Subject(s)
Biological Evolution , Genome, Plant , Poaceae/genetics , Base Composition , Chromosomes, Plant , Flowers/genetics , Flowers/growth & development , Gene Duplication , Multigene Family , Phylogeny , Plant Proteins/genetics
9.
Allergy ; 79(5): 1230-1241, 2024 05.
Article in English | MEDLINE | ID: mdl-38403941

ABSTRACT

BACKGROUND: Identifying predictive biomarkers for allergen immunotherapy response is crucial for enhancing clinical efficacy. This study aims to identify such biomarkers in patients with allergic rhinitis (AR) undergoing subcutaneous immunotherapy (SCIT) for house dust mite allergy. METHODS: The Tongji (discovery) cohort comprised 72 AR patients who completed 1-year SCIT follow-up. Circulating T and B cell subsets were characterized using multiplexed flow cytometry before SCIT. Serum immunoglobulin levels and combined symptom and medication score (CSMS) were assessed before and after 12-month SCIT. Responders, exhibiting ≥30% CSMS improvement, were identified. The random forest algorithm and logistic regression analysis were used to select biomarkers and establish predictive models for SCIT efficacy in the Tongji cohort, which was validated in another Wisco cohort with 43 AR patients. RESULTS: Positive SCIT response correlated with higher baseline CSMS, allergen-specific IgE (sIgE)/total IgE (tIgE) ratio, and frequencies of Type 2 helper T cells, Type 2 follicular helper T (TFH2) cells, and CD23+ nonswitched memory B (BNSM) and switched memory B (BSM) cells, as well as lower follicular regulatory T (TFR) cell frequency and TFR/TFH2 cell ratio. The random forest algorithm identified sIgE/tIgE ratio, TFR/TFH2 cell ratio, and BNSM frequency as the key biomarkers discriminating responders from nonresponders in the Tongji cohort. Logistic regression analysis confirmed the predictive value of a combination model, including sIgE/tIgE ratio, TFR/TFH2 cell ratio, and CD23+ BSM frequency (AUC = 0.899 in Tongji; validated AUC = 0.893 in Wisco). CONCLUSIONS: A T- and B-cell signature combination efficiently identified SCIT responders before treatment, enabling personalized approaches for AR patients.


Subject(s)
Biomarkers , Desensitization, Immunologic , Pyroglyphidae , Rhinitis, Allergic , Humans , Rhinitis, Allergic/therapy , Rhinitis, Allergic/immunology , Male , Desensitization, Immunologic/methods , Animals , Female , Adult , Pyroglyphidae/immunology , Treatment Outcome , Immunoglobulin E/blood , Immunoglobulin E/immunology , Middle Aged , Young Adult , Allergens/immunology , Allergens/administration & dosage , Antigens, Dermatophagoides/immunology , Injections, Subcutaneous , Adolescent , Prognosis
10.
Langmuir ; 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39137090

ABSTRACT

Although precise regulation of the crystalline structures of metal oxides is an effective method to improve their antibacterial activities, the corresponding mechanisms involved in this process are still unclear. In this study, three kinds of cuprous oxide (Cu2O) samples with different structures of cubes, octahedra, and rhombic dodecahedra (c-Cu2O, o-Cu2O, and r-Cu2O) have been successfully synthesized and their antibacterial activities are compared. The antibacterial activities follow the order of r-Cu2O > o-Cu2O > c-Cu2O, revealing the significant dependence of the antibacterial activities on the crystalline structures of Cu2O. Quenching experiments, as well as the NBT and DPD experiments indicate that ≡CuII─OO• superoxo and ≡CuII─OOH peroxo, instead of •OH, O2•-, and H2O2, are the primary oxidizing species in the oxidative damage to E. coli. Raman analysis further confirms the presence of both ≡CuII─OO• superoxo and ≡CuII─OOH peroxo on the surface of r-Cu2O. On the other hand, the NCP experiment reveals that Cu+, instead of Cu2+, also contributes to the antibacterial process. This study provides new insight into the antibacterial mechanisms of Cu2O.

11.
BMC Infect Dis ; 24(1): 849, 2024 Aug 21.
Article in English | MEDLINE | ID: mdl-39169329

ABSTRACT

BACKGROUND: The aim of this study was to investigate the epidemiological characteristics and antibiotic resistance patterns of Ureaplasma urealyticum (UU) infection among women and children in southwest China. METHODS: A total of 8,934 specimens, including urogenital swabs and throat swabs were analyzed in this study. All samples were tested using RNA-based Simultaneous Amplification and Testing (SAT) methods. Culture and drug susceptibility tests were performed on UU positive patients. RESULTS: Among the 8,934 patients, the overall positive rate for UU was 47.92%, with a higher prevalence observed among women of reproductive age and neonates. The majority of UU positive outpatients were women of reproductive age (88.03%), while the majority of UU positive inpatients were neonates (93.99%). Overall, hospitalization rates due to UU infection were significantly higher in neonates than in women. Further analysis among neonatal inpatients revealed a higher incidence of preterm birth and low birth weight in UU positive inpatients (52.75% and 3.65%, respectively) than in UU negative inpatients (44.64% and 2.89%, respectively), especially in very preterm and extremely preterm neonates. Moreover, the incidence rate of bronchopulmonary dysplasia (BPD) among hospitalized neonatal patients was significantly higher in the UU positive group (6.89%) than in the UU negative group (4.18%). The drug susceptibility tests of UU in the neonatology, gynecology and obstetrics departments exhibited consistent sensitivity patterns to antibiotics, with high sensitivity to tetracyclines and macrolides, and low sensitivity to fluoroquinolones. Notably, UU samples collected from the neonatology department exhibited significantly higher sensitivity to azithromycin and erythromycin (93.8% and 92.9%, respectively) than those collected from the gynecology and obstetrics departments. CONCLUSIONS: This study enhances our understanding of the current epidemiological characteristics and antibiotic resistance patterns of UU infection among women and children in southwest China. These findings can aid in the development of more effective intervention, prevention and treatment strategies for UU infection.


Subject(s)
Anti-Bacterial Agents , Drug Resistance, Bacterial , Microbial Sensitivity Tests , Ureaplasma Infections , Ureaplasma urealyticum , Humans , Ureaplasma Infections/epidemiology , Ureaplasma Infections/microbiology , Ureaplasma Infections/drug therapy , Ureaplasma urealyticum/drug effects , Ureaplasma urealyticum/isolation & purification , Ureaplasma urealyticum/genetics , Female , China/epidemiology , Infant, Newborn , Anti-Bacterial Agents/pharmacology , Adult , Male , Adolescent , Infant , Middle Aged , Young Adult , Child, Preschool , Child , Prevalence
12.
J Chem Phys ; 161(7)2024 Aug 21.
Article in English | MEDLINE | ID: mdl-39145565

ABSTRACT

The elasticities of double-stranded (ds) DNA and RNA, which are critical to their biological functions and applications in materials science, can be significantly modulated by solution conditions such as ions and temperature. However, there is still a lack of a comprehensive understanding of the role of solvents in the elasticities of dsRNA and dsDNA in a comparative way. In this work, we explored the effect of ethanol solvent on the elasticities of dsRNA and dsDNA by magnetic tweezers and all-atom molecular dynamics simulations. We found that the bending persistence lengths and contour lengths of dsRNA and dsDNA decrease monotonically with the increase in ethanol concentration. Furthermore, the addition of ethanol weakens the positive twist-stretch coupling of dsRNA, while promotes the negative twist-stretch coupling of dsDNA. Counter-intuitively, the lower dielectric environment of ethanol causes a significant re-distribution of counterions and enhanced ion neutralization, which overwhelms the enhanced repulsion along dsRNA/dsDNA, ultimately leading to the softening in bending for dsRNA and dsDNA. Moreover, for dsRNA, ethanol causes slight ion-clamping across the major groove, which weakens the major groove-mediated twist-stretch coupling, while for dsDNA, ethanol promotes the stretch-radius correlation due to enhanced ion binding and consequently enhances the helical radius-mediated twist-stretch coupling.


Subject(s)
DNA , Ethanol , Molecular Dynamics Simulation , RNA, Double-Stranded , Ethanol/chemistry , DNA/chemistry , RNA, Double-Stranded/chemistry , Elasticity , Nucleic Acid Conformation
13.
J Nanobiotechnology ; 22(1): 459, 2024 Jul 31.
Article in English | MEDLINE | ID: mdl-39085911

ABSTRACT

BACKGROUND: Sunitinib is a multikinase inhibitor used to treat patients with advanced renal cell carcinoma (RCC). However, sunitinib toxicity makes it a double-edged sword. Potent immune modulation by sunitinib extends to nuclear interactions. To address these issues, there is an urgent need for delivery vectors suitable for sunitinib treatment. METHODS: We developed PEGylated liposomes as delivery vectors to precisely target sunitinib (lipo-sunitinib) to RCC tumors. Further investigations, including RNA sequencing (RNA-seq), were performed to evaluate transcriptomic changes in these pathways. DiI/DiR-labeled lipo-sunitinib was used for the biodistribution analysis. Flow cytometry and immunofluorescence (IF) were used to examine immune modulation in orthotopic RCC models. RESULTS: The evaluation of results indicated that lipo-sunitinib precisely targeted the tumor site to induce autophagy and was readily taken up by RCC tumor cells. In addition, transcriptomic assays revealed that following lipo-sunitinib treatment, autophagy, antigen presentation, cytokine, and chemokine production pathways were upregulated, whereas the epithelial-mesenchymal transition (EMT) pathway was downregulated. In vivo data provided evidence supporting the inhibitory effect of lipo-sunitinib on RCC tumor progression and metastasis. Flow cytometry further demonstrated that liposunitinib increased the infiltration of effector T cells (Teffs) and conventional type 1 dendritic cells (cDC1s) into the tumor. Furthermore, systemic immune organs such as the tumor-draining lymph nodes, spleen, and bone marrow exhibited upregulated anticancer immunity following lipo-sunitinib treatment. CONCLUSION: Our findings demonstrated that lipo-sunitinib is distributed at the RCC tumor site, concurrently inducing potent autophagy, elevating antigen presentation, activating cytokine and chemokine production pathways, and downregulating EMT in RCC cells. This comprehensive approach significantly enhanced tumor inhibition and promoted anticancer immune modulation.


Subject(s)
Autophagy , Carcinoma, Renal Cell , Kidney Neoplasms , Liposomes , Polyethylene Glycols , Sunitinib , Carcinoma, Renal Cell/drug therapy , Sunitinib/pharmacology , Autophagy/drug effects , Animals , Liposomes/chemistry , Kidney Neoplasms/drug therapy , Mice , Cell Line, Tumor , Polyethylene Glycols/chemistry , Humans , Immunomodulation/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Tissue Distribution , Epithelial-Mesenchymal Transition/drug effects , Female
14.
J Formos Med Assoc ; 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39306515

ABSTRACT

BACKGROUND: In 2022, the SARS-CoV-2 Omicron surge affected 8.8 million people in Taiwan. This study delves into how the transition from containment to mitigation strategies in COVID-19 control has altered concerns regarding transfusion safety. METHODS: Blood donations during 2020-2022 in Taiwan were included. Donation details and post-donation information (PDI) were retrieved to assess donation fluctuations and incidences of various PDI. The main effects of PDI reporting were assessed using chi-square test and logistic regression. Additionally, from April to August 2022, we collected disease information from COVID-19 donors, and tested their repository specimens for SARS-CoV-2 RNA and antibodies. RESULTS: Before 2022, when containment measures were in place, only 8 blood donors with COVID-19 reported PDI. However, by mid-2021, there was a significant decrease in blood donations. In 2022, with mitigation strategies implemented, a total of 3483 donations reported COVID-19 PDI. The incidence of all cause PDI increased from 10.5 per 10,000 donations in 2020-2021 to 29.9 per 10,000 in 2022, with nearly 70% of PDI being related to COVID-19. Female donors reported more PDI events. Additionally, the incidence significantly decreased with age. A total of 1148 repository specimens from COVID-19 donor were tested, revealing no detection of SARS-CoV-2 RNA. The seroprevalence rates of anti-nucleocapsid(N) and anti-spike(S) antibodies were 0.61% and 98.4%, respectively. CONCLUSION: Transfusion safety concerns in Taiwan progressed alongside the evolution of control strategies, with a one-year delay following the pandemic started. The absence of RNAemia among COVID-19 donors indicates that precautionary measures were commensurate with the risk.

15.
Nano Lett ; 23(14): 6602-6609, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37449842

ABSTRACT

Nontrivial polarization textures have been demonstrated in ferroelectric/dielectric superlattices, where the electrostatic, elastic, and different gradient energies compete in a delicate balance. When PbTiO3/SrTiO3 superlattices are grown on DyScO3, the coexistence of ferroelectric domains and vortex structure is observed for n = 12-20 unit cells. Here, we report an approach to achieve single-phase vortex structures in superlattices by controlling the epitaxial strain using Sr1.04Al0.12Ga0.35Ta0.50O3 substrates. The domain width follows Kittel's law with the thickness of the ferroelectric PbTiO3 layers. A phase transition from vortex to a disordered phase with temperature is characterized by the correlation length. Resonant soft X-ray diffraction circular dichroism at the titanium L-edge reveals enhanced chirality with the thickness of the ferroelectric layer. These results are supported by second-principles simulations, which demonstrate that the integrated helicity increases with n. The stabilization of chiral single-phase polar vortices in ferroelectric/dielectric superlattices can enable novel optoelectronic devices with enhanced ferroelectric-light interaction.

16.
Nano Lett ; 23(4): 1522-1529, 2023 Feb 22.
Article in English | MEDLINE | ID: mdl-36722976

ABSTRACT

Antiferroelectrics characterized by voltage-driven reversible transitions between antiparallel and parallel polarity are promising for cutting-edge electronic and electrical power applications. Wide-ranging explorations revealing the macroscopic performances and microstructural characteristics of typical antiferroelectric systems have been conducted. However, the underlying mechanism has not yet been fully unraveled, which depends largely on the atomistic processes. Herein, based on atomic-resolution transmission electron microscopy, the deterministic phase transition pathway along with the underlying lattice-by-lattice details in lead zirconate thin films was elucidated. Specifically, we identified a new type of ferrielectric-like dipole configuration with both angular and amplitude modulations, which plays the role of a precursor for a subsequent antiferroelectric to ferroelectric transformation. With the participation of the ferrielectric-like phase, the phase transition pathways driven by the phase boundary have been revealed. We provide new insights into the consecutive phase transformation in low-dimensional lead zirconate, which thus would promote potential antiferroelectric-based multifunctional devices.

17.
Molecules ; 29(14)2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39065015

ABSTRACT

Seven new lanthanide coordination polymers, namely [Ln(cpt)3H2O)]n(Ln = La (1), Pr (2), Sm (3), Eu (4), Gd (5), Dy (6), and Er (7)), which were synthesized under hydrothermal conditions using 4'-(4-(4-carboxyphenyloxy)phenyl)-4,2':6',4'-tripyridine (Hcpt) as the ligand. The crystal structures of these seven complexes were determined using single-crystal X-ray diffraction, and they were found to be isostructural, crystallizing in the triclinic P1- space group. The Ln(III) ions were nine-coordinated with tricapped trigonal prism coordination geometry. The Ln(III) cations were coordinated by carboxylic and pyridine groups from (cpt)- ligands, forming one-dimensional ring-chain structures. Furthermore, the luminescent properties of complexes 1-7 were investigated using fluorescent spectra in the solid state. The fluorescence sensing experiments demonstrated that complex 4 exhibits high selectivity and sensitivity for detecting Co2+, Cu2+ ions, and nitrobenzene. Moreover, complex 3 shows good capability for detecting Cu2+ ions and nitrobenzene. Additionally, the sensing mechanism was also thoroughly examined through theoretical calculations.

18.
Yi Chuan ; 46(5): 360-372, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38763771

ABSTRACT

In order to understand the progress and frontier in the application of BSA(bulked segregant analysis) method in crop breeding and to reflect objectively the contribution of different countries, institutions and researchers in this field at home and abroad, this study analyzed 2111 items in the WOS (Web of Science) database from 2000 to 2023 and 446 items in the CNKI (China National through Knowledge Infrastructure) database from 2003 to 2023, regarding the researches of the application of BSA in crop breeding, basing on bibliometric analysis methods using CiteSpace software including keyword co-occurrence analysis, highlight word analysis, keyword clustering analysis, clustering timeline analysis and author co-citation. The results showed that there was an consistent increasing trend in the publication number of the application of BSA in crop breeding both in the domestic and foreign journals year by year. Ranking of the top countries according to the number of publications was China, the United States and India. The Huazhong Agricultural University displayed the highest number of publications in the CNKI database, while the Chinese Academy of Agricultural Sciences was found to have the highest number of publications in the WOS database. The published articles related to the application of BSA in crop breeding abroad mainly focused on the disciplines such as plant science, agronomy, horticulture and genetics, while those in China mainly concentrated on such disciplines as plant science, plant protection, horticulture and biology. The top three authors in terms of influence in the field of appling BSA in crop breeding were Michelmore RW, Kosambi DD and Li H, while Michelmore RW, Lander ES and Li H had closer cooperations with other authors. The top three crops relating to the studies of BSA were rice(Oryza sativa), soybean(Glycine max), corn(Zea mays L.) with the hot spot traits of disease resistance and plant height domestically. The top three crops involving the studies of BSA were rice, Arabidopsis thaliana and wheat(Triticum aestivum L.) with hot spot traits of disease resistance abroad. Up to now, BSA was mainly used to localize and functionally verify the candidate genes linking target traits and the mutated genes in crops in the domestical documents, while the foreign published studies based on BSA were mainly focused on the fine mapping and functional verification of target trait genes aiming at the revelation of genetic mechanisms in crops. Research frontier analysis indicated that rice, peanuts(Arachis hypogaea L.), upland cotton(Gossypium hirsutum L.) would be the main objects of studies concerning application of BSA in crop breeding with the hot topics of crop mutants and crop metabolites in the future.


Subject(s)
Bibliometrics , Crops, Agricultural , Plant Breeding , Crops, Agricultural/genetics , Plant Breeding/methods , China
19.
Zhongguo Zhong Yao Za Zhi ; 49(10): 2689-2698, 2024 May.
Article in Zh | MEDLINE | ID: mdl-38812169

ABSTRACT

This study aims to prepare co-loaded indocyanine green(ICG) and elemene(ELE) nano-emulsion(NE) in situ gel(ICG-ELE-NE-gel) and evaluate its physicochemical properties and antitumor activity in vitro. ICG-ELE-NE-gel was prepared by aqueous phase titration and cold solution methods, followed by characterization of the morphology, particle size, corrosion, and photothermal conversion characteristics. The human breast cancer MCF-7 cells were taken as the model, combined with 808 nm laser irradia-tion. Cell inhibition rate test and cell uptake test were performed. ICG-ELE-NE was spherical and uniform in size. The average particle size and Zeta potential were(85.61±0.35) nm and(-21.4±0.6) mV, respectively. The encapsulation efficiency and drug loading rate were 98.51%±0.39% and 10.96%±0.24%, respectively. ICG-ELE-NE-gel had a good photothermal conversion effect and good photothermal stability. The dissolution of ICG-ELE-NE-gel had both temperature and pH-responsive characteristics. Compared with free ELE, ICG-ELE-NE-gel combined with near-infrared light irradiation significantly enhanced the inhibitory effect on MCF-7 cells and could be uptaken in large amounts by MCF-7 cells. ICG-ELE-NE-gel was successfully prepared, and its antitumor activity was enhanced after 808 nm laser irradiation.


Subject(s)
Breast Neoplasms , Cell Proliferation , Emulsions , Indocyanine Green , Humans , Indocyanine Green/chemistry , MCF-7 Cells , Emulsions/chemistry , Cell Proliferation/drug effects , Female , Particle Size , Gels/chemistry , Nanoparticles/chemistry , Drug Compounding/methods , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , Drug Carriers/chemistry
20.
Angew Chem Int Ed Engl ; 63(15): e202400577, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38284909

ABSTRACT

Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have exhibited encouraging oxygen reduction reaction (ORR) activity. Nevertheless, the insufficient long-term stability remains a widespread concern owing to the inevitable 2-electron byproducts, H2O2. Here, we construct Co-N-Cr cross-interfacial electron bridges (CIEBs) via the interfacial electronic coupling between Cr2O3 and Co-N-C, breaking the activity-stability trade-off. The partially occupied Cr 3d-orbitals of Co-N-Cr CIEBs induce the electron rearrangement of CoN4 sites, lowering the Co-OOH* antibonding orbital occupancy and accelerating the adsorption of intermediates. Consequently, the Co-N-Cr CIEBs suppress the two-electron ORR process and approach the apex of Sabatier volcano plot for four-electron pathway simultaneously. As a proof-of-concept, the Co-N-Cr CIEBs is synthesized by the molten salt template method, exhibiting dominant 4-electron selectively and extremely low H2O2 yield confirmed by Damjanovic kinetic analysis. The Co-N-Cr CIEBs demonstrates impressive bifunctional oxygen catalytic activity (▵E=0.70 V) and breakthrough durability including 100 % current retention after 10 h continuous operation and cycling performance over 1500 h for Zn-air battery. The hybrid interfacial configuration and the understanding of the electronic coupling mechanism reported here could shed new light on the design of superdurable M-N-C catalysts.

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