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1.
Small Methods ; : e2400258, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38962863

RESUMO

Nanoengineering polar oxide films have attracted great attention in energy storage due to their high energy density. However, most of them are deposited on thick and rigid substrates, which is not conducive to the integration of capacitors and applications in flexible electronics. Here, an alternative strategy using van der Waals epitaxial oxide dielectrics on ultra-thin flexible mica substrates is developed and increased the disorder within the system through high laser flux. The introduction of defects can efficiently weaken or destroy the long-range ferroelectric ordering, ultimately leading to the emergence of a large numbers of weak-coupling regions. Such polarization configuration ensures fast polarization response and significantly improves energy storage characteristics. A flexible BiFeO3-BaTiO3 (BF-BT) capacitor exhibits a total energy density of 43.5 J cm-3 and an efficiency of 66.7% and maintains good energy storage performance over a wide temperature range (20-200 °C) and under large bending deformation (bending radii ≈ 2 mm). This study provides a feasible approach to improve the energy storage characteristics of dielectric oxide films and paves the way for their practical application in high-energy density capacitors.

2.
Front Psychol ; 15: 1290793, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38836237

RESUMO

Background: Investigating the effects of monetary incentives on dishonest behavior provides valuable insights into human integrity and ethical decision-making processes. This study is conducted through the lens of self-concept maintenance theory. Aim: The aim of this study is to examine the influence of different types of rewards (score-based vs. monetary) and their magnitude on dishonest behavior within a gender judgment task. Method: Using a quantitative experimental design, this study involved 116 participants who were randomly assigned to conditions that differed in reward type (score or money) and magnitude (10 yuan vs. 50 yuan). Dishonest behavior was assessed using a gender judgment task with mechanisms to simulate conditions conducive to planned cheating. Results: Results revealed significant differences in dishonesty rates between score and money conditions, with a higher proportion of dishonest participants observed in the score condition compared to the money condition. The timing of initial cheating was earlier in the score condition compared to the money condition. No significant differences were found in the proportion of dishonest participants, the cheating rate, or the timing of initial cheating across reward levels within either condition. The rate of cheating increased over time, suggesting a temporal dynamic in unethical decision making. Conclusion: The study demonstrates that the nature of rewards significantly influences the likelihood of dishonest behavior, with intangible score-based rewards facilitating rationalizations for dishonesty more readily than tangible financial incentives. These findings enrich the understanding of moral psychology by highlighting the complex interplay between reward types, ethical rationalization, and the dynamics of dishonest behavior.

3.
Immunology ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38840413

RESUMO

Lung adenocarcinoma (LUAD) is the most prevalent subtype of lung cancer, and the early detection and diagnosis of this disease are crucial in reducing mortality rates. The timely diagnosis of LUAD is essential for controlling tumour development and enabling early surgical treatment. GPR56 is a vital G protein-coupled receptor and its role in T lymphocytes has received considerable attention. However, its function in B cells remains unclear. This study aimed to investigate the significance of GPR56 in LUAD. We found that GPR56 exhibited a significant increase in circulating plasmablasts and a decrease in new memory B cells. GPR56 expression in B cells was significantly reduced after LPS stimulation and the proportion of HLA-DR+ and CD40+ proportions were also decreased in GPR56+ B cells after stimulation. Additionally, GPR56 exhibited significant down-regulation in circulating B cell subsets of early-stage LUAD patients, and there were significant correlations between GPR56+ B cell subsets and tumour markers. In conclusion, GPR56 could reflect the hypoactivation state of B cells and the decreased proportion of GPR56+ B cell subset in LUAD patients can signify the active humoral immunity in vivo. The expression of GPR56 in B cells could potentially hold value in the early diagnosis of LUAD.

4.
J Leukoc Biol ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38833584

RESUMO

As one molecule related to cytotoxicity, surface expression of C-X3-C motif receptor 1 (CX3CR1) was highly correlated with intracellular granzyme B (GZMB) in NK and cytolytic T cells. However, the expression of CX3CR1 and GZMB in B cells has not been clarified, and their clinical significance in systemic lupus erythematosus (SLE) remains unclear. This study aimed to clarify the changes and clinical significance of peripheral blood B cells expressing GZMB and/or CX3CR1 in SLE. Peripheral blood was collected from 39 SLE patients and 48 healthy controls. We found that GZMB and CX3CR1 expression varied in different B-cell subsets, with plasmablasts possessing the highest positive percentages, consistent with bioinformatics prediction. GZMB+ and CX3CR1+ percentages in circulating B cells and plasmablasts were increased in SLE patients. CX3CR1 was upregulated on B cells after in vitro stimulation. Notch intracellular domain (NICD) expression was significantly decreased in plasmablasts of SLE patients and CX3CR1 in plasmablasts was downregulated with the addition of JAG1. In conclusion, GZMB and CX3CR1 were increased in B cells and in plasmablasts of SLE patients and CX3CR1 was negatively regulated by Notch signal in plasmablasts, which may be involved in SLE pathogenesis.

5.
Adv Mater ; : e2403929, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744294

RESUMO

2D polarization materials have emerged as promising candidates for meeting the demands of device miniaturization, attributed to their unique electronic configurations and transport characteristics. Although the existing inherent and sliding mechanisms are increasingly investigated in recent years, strategies for inducing 2D polarization with innovative mechanisms remain rare. This study introduces a novel 2D Janus state by modulating the puckered structure. Combining scanning probe microscopy, transmission electron microscopy, and density functional theory calculations, this work realizes force-triggered out-of-plane and in-plane dipoles with distorted smaller warping in GeSe. The Janus state is preserved after removing the external mechanical perturbation, which could be switched by modulating the sliding direction. This work offers a versatile method to break the space inversion symmetry in a 2D system to trigger polarization in the atomic scale, which may open an innovative insight into configuring novel 2D polarization materials.

6.
Front Psychol ; 15: 1379705, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784620

RESUMO

Background: The exploration of personality traits in relation to psychological constructs has become increasingly relevant in understanding the mental health of university students (the emerging adulthood). Studies have focused on how dimensions intersect with various psychological parameters. Aim: The study aims to identify distinct personality profiles among university students based on Eysenck's personality dimensions and investigate how these profiles differ across psychological constructs. Method: A quantitative methodology was utilized, involving 708 university students from Wenzhou and Nanjing in China as participants. The research employed the Eysenck Personality Questionnaire along with other psychological measures. Latent Profile Analysis was applied to categorize the participants into distinct personality profiles. Results: Four distinct personality profiles emerged: 'The Reserved Analyst,' 'The Social Diplomat,' 'The Unconventional Pragmatist,' and 'The Impulsive Truth-Teller.' Significant differences were found among these profiles on various psychological constructs. 'The Social Diplomat' exhibited the most adaptive psychological profile, with higher cognitive reappraisal (F = 45.818, p < 0.001, η2 = 0.163), meaning in life (F = 17.764, p < 0.001, η2 = 0.070), and positive coping (F = 40.765, p < 0.001, η2 = 0.148) compared to other profiles. Conversely, 'The Reserved Analyst' showed higher intolerance of uncertainty (F = 13.854, p < 0.001, η2 = 0.056) and state anxiety (F = 26.279, p < 0.001, η2 = 0.101). Conclusion: This study enriches the understanding of personality traits in relation to psychological constructs within the context of university student populations. By identifying distinct personality profiles, it lays the groundwork for developing tailored mental health strategies that cater to the specific needs of different student groups.

7.
Sci Adv ; 10(22): eadk9928, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820158

RESUMO

The proton-electron coupling effect induces rich spectrums of electronic states in correlated oxides, opening tempting opportunities for exploring novel devices with multifunctions. Here, via modest Pt-aided hydrogen spillover at room temperature, amounts of protons are introduced into SmNiO3-based devices. In situ structural characterizations together with first-principles calculation reveal that the local Mott transition is reversibly driven by migration and redistribution of the predoped protons. The accompanying giant resistance change results in excellent memristive behaviors under ultralow electric fields. Hierarchical tree-like memory states, an instinct displayed in bio-synapses, are further realized in the devices by spatially varying the proton concentration with electric pulses, showing great promise in artificial neural networks for solving intricate problems. Our research demonstrates the direct and effective control of proton evolution using extremely low electric field, offering an alternative pathway for modifying the functionalities of correlated oxides and constructing low-power consumption intelligent devices and neural network circuits.

8.
Eur J Immunol ; 54(5): e2350739, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38461541

RESUMO

Using data from single-cell RNA sequencing and flow cytometry, we initially examined the expression of FCRL3, finding it to be elevated and positively associated with TIGIT expression in the regulatory T cells of patients with systemic lupus erythematosus. This also suggests that the co-expression of FCRL3 and TIGIT warrants further attention.


Assuntos
Lúpus Eritematoso Sistêmico , Receptores Imunológicos , Linfócitos T Reguladores , Humanos , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/genética , Linfócitos T Reguladores/imunologia , Regulação para Cima/imunologia , Feminino , Masculino , Adulto
9.
Int Immunopharmacol ; 126: 111231, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38016349

RESUMO

OBJECTIVE: This study investigated CX3CR1 expression in human peripheral blood T lymphocytes and their subsets, exploring changes in SLE patients and its diagnostic potential. METHODS: Peripheral blood samples from 31 healthy controls and 50 SLE patients were collected. RNA-Seq data from SLE patient PBMCs were used to analyze CX3CR1 expression in T cells. Flow cytometry determined CX3CR1-expressing T lymphocyte subset proportions in SLE patients and healthy controls. Subset composition and presence of GZMB, GPR56, and perforin in CX3CR1+ T lymphocytes were analyzed. T cell-clinical indicator correlations were assessed. ROC curves explored CX3CR1's diagnostic potential for SLE. RESULTS: CX3CR1+CD8+ T cells exhibited higher GPR56, perforin, and GZMB expression than other T cell subsets. The proportion of CX3CR1+ was higher in TEMRA and lower in Tn and TCM. PMA activation reduced CX3CR1+ T cell proportions. Both RNA-Seq and flow cytometry revealed elevated CX3CR1+ T cell proportions in SLE patients. Significantly lower perforin+ and GPR56+ proportions were observed in CX3CR1+CD8+ T cells in SLE patients. CX3CR1+ T cells correlated with clinical indicators. CONCLUSION: CX3CR1+ T cells display cytotoxic features, with heightened expression in CD8+ T cells, particularly in adult SLE patients. Increased CX3CR1 expression in SLE patient T cells suggests its potential as an adjunctive diagnostic marker for SLE.


Assuntos
Antineoplásicos , Lúpus Eritematoso Sistêmico , Adulto , Humanos , Perforina/genética , Perforina/metabolismo , Regulação para Cima , Subpopulações de Linfócitos T , Linfócitos T CD8-Positivos , Antineoplásicos/metabolismo , Citometria de Fluxo , Receptor 1 de Quimiocina CX3C/metabolismo
10.
J Am Chem Soc ; 145(49): 26791-26798, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-37972388

RESUMO

Knot-like structures were found to have interesting magnetic properties in condensed matter physics. Herein, we report on topologically chiral molecular knots as efficient spintronic chiral material. The discovery of the chiral-induced spin selectivity (CISS) effect opens the possibility of manipulating the spin orientation with soft materials at room temperature and eliminating the need for a ferromagnetic electrode. In the chiral molecular trefoil knot, there are no stereogenic carbon atoms, and chirality results from the spatial arrangements of crossings in the trefoil knot structures. The molecules show a very high spin polarization of nearly 90%, a conductivity that is higher by about 2 orders of magnitude compared with that of other chiral small molecules, and enhanced thermal stability. A plausible explanation for these special properties is provided, combined with model calculations, that supports the role of electron-electron interaction in these systems.

11.
Vet Microbiol ; 285: 109872, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37690146

RESUMO

Vaccines are widely used to prevent Newcastle disease virus (NDV). Under the pressure of immunization, NDVs with mutations among epitopes of F and HN protein were isolated, which indicates that the efficiency of vaccine may decrease in terms of preventing emerged NDV. However, the lack of evidences to support whether these mutations contribute to antigenic mutation and immune escape in NDV leading to the controversy that the matched vaccine is more effective than the mismatched vaccine. In this study, a genotype VII velogenic NDV strain (C22) was isolated from a vaccinated farm in Tibet, China. We found that this strain was close to NDV from east China, but it had a specific mutation (K138R) in one epitope (131DYIGGIGKE139) of HN protein. This mutation might change the interaction between amino acids in stalk-head link region of HN protein and then induce the specific antibody to worse recognize the C22 strain, but it did not alter viral virulence and growth ability. Then, the C22 strain was attenuated via modification of the F protein cleavage site to generate a matched vaccine. Comparing to a mismatched vaccine (LaSota), this matched vaccine showed advantages in inhibiting viral shedding and tissue damage. However, both vaccines induced chicken to generate similar level of neutralizing antibodies against C22, C22mut (R138K) and LaSota. These results suggest that the epitope mutation is insufficient to help NDV escaping neutralizing antibodies of vaccinated chicken, supporting that the merits of NDV matched vaccine are not totally related to humoral immunity.


Assuntos
Doença de Newcastle , Vacinas Virais , Animais , Vírus da Doença de Newcastle , Hemaglutininas/genética , Neuraminidase/genética , Tibet , Proteína HN/genética , Vacinas Virais/genética , Galinhas , Proteínas Virais/genética , Anticorpos Neutralizantes/genética , China , Variação Antigênica , Epitopos/genética , Anticorpos Antivirais , Genótipo
12.
Immunol Invest ; 52(7): 879-896, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37642473

RESUMO

OBJECTIVE: To investigate the expression of layilin (LAYN) in human circulating monocytes and lymphocytes and its clinical significance in systemic lupus erythematosus (SLE). METHODS: Blood samples were collected from 51 SLE patients and 50 healthy controls. Flow cytometry was used to analyze LAYN in lymphocytes and monocyte subsets. Functionally characterized molecules including human HLA, CD74 and CD62L were studied in LAYN+ monocytes. A correlation analysis was conducted between LAYN-related subsets and clinical indicators of SLE such as anti-double-stranded DNA and complements levels. ROC curves were used to explore the potential clinical diagnostic value of LAYN in SLE. RESULTS: LAYN was significantly higher in monocytes than in lymphocytes and higher in CD14+CD16+ monocytes than in CD14-CD16+ and CD14+CD16- monocytes. CD74 was upregulated and CD62L was downregulated in LAYN+ monocytes compared with LAYN- monocytes. The absolute number of LAYN+ monocytes was increased in SLE patients, and the median fluorescence intensity of HLA was decreased. LAYN+ monocytes were positively correlated with complement C4, while decreased CD62L+ percentages in LAYN+ monocytes were negatively correlated with C4. The ROC analysis revealed that the area under the curve (AUCs) for CD62L+ percentages in LAYN+ monocytes, LAYN+ lymphocyte numbers, and LAYN+ monocyte numbers to distinguish SLE from healthy individuals were 0.6245, 0.6196 and 0.6173, respectively. CONCLUSION: LAYN is differentially expressed in monocytes and their subpopulations and has corresponding functional differences. Changes in LAYN expression on monocytes are associated with complement C4 levels in SLE patients. These suggest that LAYN may be involved in the pathogenesis of SLE. ABBREVIATION: ANOVA: analysis of variance; anti-dsDNA: anti-double-stranded DNA; anti-ENA: anti-extractable nuclear antigen; anti-SSA: anti-Sjogren syndrome A; anti-SSB: anti-Sjogren syndrome B; anti-U1RNP: anti-U1 ribonucleoprotein; AUC: area under the ROC curve; CBC: complete blood count; CD62L: L-selectin; CD74/Ii: MHC class II invariant chain; CD44/HCAM: homing cell adhesion molecule; cMos: classical monocytes; CRP: C-reactive protein; CXCR2: C-X-C motif chemokine receptor 2; CXCR4: C-X-C motif chemokine receptor 4; ESR: erythrocyte sedimentation rate; HCs: healthy controls; HA: hyaluronan; HLA: human leukocyte antigen; Ig: immunoglobulin; iMos: intermediate monocytes; LAYN: layilin; MFI: median fluorescence intensity; MIF: migration inhibitory factor; ncMos: nonclassical monocytes; PBMCs: peripheral blood mononuclear cells; ROC: receiver operating characteristic curve; SLE: systemic lupus erythematosus; SLEDAI, SLE disease activity index; Treg: regulatory T cells; WBCs: white blood cells.


Assuntos
Lúpus Eritematoso Sistêmico , Monócitos , Humanos , Leucócitos Mononucleares , Complemento C4 , Anticorpos Antinucleares , Receptores de Quimiocinas , Lectinas Tipo C
13.
Microbiol Spectr ; 11(3): e0402422, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37036344

RESUMO

When it comes to the prevention of clinical signs and mortality associated with infection of the Newcastle disease virus (NDV), vaccination has been very effective. However, recent evidence has proven that more highly virulent strains are emerging that bypass existing immune protection and pose a serious threat to the global poultry industry. Here, a novel rescued adenovirus 5-coexpressed chicken granulocyte monocyte colony-stimulating factor (ChGM-CSF) bio-adjuvant and C22-hemagglutinin-neuraminidase (HN) boosted chickens' immunological genetic resistance and thus improved the immunological effectiveness of the critical new-generation vaccine in vitro and in vivo. Accordingly, the hemagglutination inhibition (HI) titers (log2) of the recombinant adenovirus (rAdv)-ChGM-CSF-HN-immunized chickens had greater, more persistent, and longer-lasting NDV-specific antibodies than the La Sota and rAdv-HN-inoculated birds. Moreover, humoral and adaptive immunological conditions were shown to be in harmony after rAdv-ChGM-CSF-HN inoculation and uniformly enhanced the expression of alpha interferon (IFN-α), IFN-ß, IFN-γ, interleukin-1ß (IL-1ß), IL-2, IL-16, IL-18, and IL-22. Postchallenge, the control challenge (CC), wild-type adenovirus (wtAdv), and rAdv-ChGM-CSF groups developed unique NDV clinical manifestations, significant viral shedding, high tissue viral loads, gross and microscopic lesions, and 100% mortality within 7 days. The La Sota, rAdv-HN, and rAdv-ChGM-CSF-HN groups were healthy and had 100% survival rates. The rAdv-ChGM-CSF-HN group swiftly regulated and stopped viral shedding and had lower tissue viral loads than all groups at 5 days postchallenge (dpc). Thus, the antiviral activity of ChGM-CSF offered robust immune protection in the face of challenge and reduced viral replication convincingly. Our advance innovation concepts, combining ChGM-CSF with a field-circulating strain epitope, could lead to the development of a safe, genotype-matched, universal transgenic vaccine that could eradicate the disease globally, reducing poverty and food insecurity. IMPORTANCE We studied the biological characterization of the developed functional synthetic recombinant adenoviruses, which showed a high degree of safety, thermostability, and genetic stability for up to 20 passages. It was demonstrated through both in vitro and in vivo testing that the immunogenicity of the proposed vaccine, which uses the T2A peptide from the Thosea asigna virus capsid protein supported by glycine and serine, helps with efficiency to generate a multicistronic vector, enables expression of two functional proteins in rAdv-ChGM-CSF-HN, and is superior to that of comparable vaccines. Additionally, adenovirus can be used to produce vaccines matching the virulent field-circulating strain epitope. Because there is no preexisting human adenoviral immunity detected in animals, the potency of adenoviral vaccines looks promising. Also, it ensures that the living vector does not carry the resistance gene that codes for the kanamycin antibiotic. Accordingly, a human recombinant adenoviral vaccine that has undergone biological improvements is beneficial and important.


Assuntos
Infecções por Adenoviridae , Doença de Newcastle , Doenças das Aves Domésticas , Vacinas Virais , Humanos , Animais , Vírus da Doença de Newcastle/genética , Galinhas , Neuraminidase , Hemaglutininas , Doença de Newcastle/prevenção & controle , Adenoviridae , Antivirais , Monócitos , Vacinas Virais/genética , Vacinas Sintéticas , Genótipo , Anticorpos Antivirais , Fatores Estimuladores de Colônias/genética , Granulócitos
14.
Tree Physiol ; 43(6): 965-978, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-36864631

RESUMO

Many studies have investigated the photoprotective and photosynthetic capacity of plant leaves, but few have simultaneously evaluated the dynamic changes of photoprotective capacity and photosynthetic maturation of leaves at different developmental stages. As a result, the process between the decline of photoprotective substances and the onset of photosynthetic maturation during plant leaf development are still poorly understood, and the relationship between them has not been quantitatively described. In this study, the contents of photoprotective substances, photosynthetic pigment content and photosynthetic capacity of leaves at different developmental stages from young leaves to mature leaves were determined by spatio-temporal replacement in eight dominant tree species in subtropical evergreen broadleaved forests. The correlation analysis found that the data sets of anthocyanins, flavonoids, total phenolics and total antioxidant capacity were mainly distributed on one side of the symmetry axis (y = x), while the data sets of flavonoids, total phenolics and total antioxidant capacity were mainly distributed on both sides of the symmetry axis (y = x). In addition, the content of photoprotective substances in plant leaves was significantly negatively correlated with photosynthetic pigment content and photosynthetic capacity but was significantly positively correlated with dark respiration rate (Rd). When chlorophyll accumulated to ~50% of the final value, the photoprotective substance content and Rd of plant leaves reached the lowest level, and anthocyanins disappeared completely; in contrast, the photosynthetic capacity reached the highest level. Our results suggest that anthocyanins mainly play a light-shielding role in the young leaves of most plants in subtropical forests. In addition, 50% chlorophyll accumulation in most plant leaves was the basis for judging leaf photosynthetic maturity. We also believe that 50% chlorophyll accumulation is a critical period in the transition of plant leaves from high photoprotective capacity (high metabolic capacity, low photosynthetic capacity) to low photoprotective capacity (low metabolic capacity, high photosynthetic capacity).


Assuntos
Antocianinas , Árvores , Árvores/metabolismo , Antocianinas/metabolismo , Antioxidantes/metabolismo , Fotossíntese , Florestas , Clorofila/metabolismo , Folhas de Planta
15.
ACS Appl Mater Interfaces ; 14(32): 36825-36833, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35929806

RESUMO

Ferroelectric solid solutions with composition near the morphotropic phase boundary (MPB) have gained extensive attention recently due to their excellent ferroelectric and piezoelectric properties. Here, we have demonstrated a strategy to realize the controllable preparation of BiFeO3-BaTiO3 (BF-BT) epitaxial films near the MPB. A series of high-quality BF-BT films were fabricated by pulsed laser deposition via adjusting oxygen partial pressure (PO2) using a BF-BT ceramic target. A continuous transition from rhombohedral to tetragonal phase was observed upon increasing PO2. Particularly, the film with a pure tetragonal phase exhibited a large remnant polarization of ∼90.6 µC/cm2, while excellent piezoelectric performance with an ultrahigh strain (∼0.48%) was obtained in the film with coexisting rhombohedral and tetragonal phases. The excellent ferroelectric and piezoelectric properties endow the BF-BT system near the MPB with great application prospects in lead-free electronic devices.

16.
Nano Lett ; 22(12): 4792-4799, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35639474

RESUMO

HfO2-based films with high compatibility with Si and complementary metal-oxide semiconductors (CMOS) have been widely explored in recent years. In addition to ferroelectricity and antiferroelectricity, flexoelectricity, the coupling between polarization and a strain gradient, is rarely reported in HfO2-based films. Here, we demonstrate that the mechanically written out-of-plane domains are obtained in 10 nm Hf0.5Zr0.5O2 (HZO) ferroelectric film at room temperature by generating the stress gradient via the tip of an atomic force microscope. The results of scanning Kelvin force microscopy (SKPM) exclude the possibility of flexoelectric-like mechanisms and prove that charge injection could be avoided by mechanical writing and thus reveal the true polarization state, promoting wider flexoelectric applications and ultrahigh-density storage of HZO thin films.

17.
Research (Wash D C) ; 2022: 9847949, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35265849

RESUMO

A novel class of polymers and oligomers of chiral folding chirality has been designed and synthesized, showing structurally compacted triple-column/multiple-layer frameworks. Both uniformed and differentiated aromatic chromophoric units were successfully constructed between naphthyl piers of this framework. Screening monomers, catalysts, and catalytic systems led to the success of asymmetric catalytic Suzuki-Miyaura polycouplings. Enantio- and diastereochemistry were unambiguously determined by X-ray structural analysis and concurrently by comparison with a similar asymmetric induction by the same catalyst in the asymmetric synthesis of a chiral three-layered product. The resulting chiral polymers exhibit intense fluorescence activity in a solid form and solution under specific wavelength irradiation.

18.
ACS Nano ; 16(1): 1308-1317, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-34978807

RESUMO

Searching van der Waals ferroic materials that can work under ambient conditions is of critical importance for developing ferroic devices at the two-dimensional limit. Here we report the experimental discovery of electric-field-induced reversible antiferroelectric (AFE) to ferroelectric (FE) transition at room temperature in van der Waals layered α-GeSe, employing Raman spectroscopy, transmission electron microscopy, second-harmonic generation, and piezoelectric force microscopy consolidated by first-principles calculations. An orientation-dependent AFE-FE transition provides strong evidence that the in-plane (IP) polarization vector aligns along the armchair rather than zigzag direction in α-GeSe. In addition, temperature-dependent Raman spectra showed that the IP polarization could sustain up to higher than 700 K. Our findings suggest that α-GeSe, which is also a potential ferrovalley material, could be a robust building block for creating artificial 2D multiferroics at room temperature.

19.
Chemistry ; 28(7): e202200183, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35092103

RESUMO

Invited for the cover of this issue are Guigen Li's groups at Texas Tech University and Nanjing University. The cover artwork shows that chirality patterns exist from universal to molecular levels showing light emission properties. Read the full story of multilayer 3D chirality and its asymmetric catalytic synthesis at 10.1002/chem.202104102.


Assuntos
Polímeros , Catálise , Humanos
20.
Chemistry ; 28(7): e202104102, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34962686

RESUMO

Unprecedented chiral multilayer folding 3D polymers have been assembled and regulated by uniform and differentiated aromatic chromophore units between naphthyl piers. Screening catalysts, catalytic systems and monomers were proven to be crucial for asymmetric catalytic Suzuki-Miyaura polycouplings for this assembly. X-ray crystallography of the corresponding dimers and trimers revealed the absolute configuration and the intermolecular packing pattern. Up to 61 960 Mw /41 900 Mn and m/z 4317 for polymers and oligomers, as confirmed by gel permeation chromatography (GPC) and MALDI-TOF MS, indicated that these frameworks were composed of multiple stacked layers. The resulting multiple π-assemblies exhibited remarkable optical properties in aggregated states (photoluminescence in solids and aggregation-induced emission in solutions), as well as reversible redox properties in electrochemical performance.


Assuntos
Polímeros , Catálise , Cromatografia em Gel , Cristalografia por Raios X
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