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1.
Proc Natl Acad Sci U S A ; 121(12): e2309054121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38466840

RESUMO

COVID-19 forced students to rely on online learning using multimedia tools, and multimedia learning continues to impact education beyond the pandemic. In this study, we combined behavioral, eye-tracking, and neuroimaging paradigms to identify multimedia learning processes and outcomes. College students viewed four video lectures including slides with either an onscreen human instructor, an animated instructor, or no onscreen instructor. Brain activity was recorded via fMRI, visual attention was recorded via eye-tracking, and learning outcome was assessed via post-tests. Onscreen presence of instructor, compared with no instructor presence, resulted in superior post-test performance, less visual attention on the slide, more synchronized eye movements during learning, and higher neural synchronization in cortical networks associated with socio-emotional processing and working memory. Individual variation in cognitive and socio-emotional abilities and intersubject neural synchronization revealed different levels of cognitive and socio-emotional processing in different learning conditions. The instructor-present condition evoked increased synchronization, likely reflecting extra processing demands in attentional control, working memory engagement, and socio-emotional processing. Although human instructors and animated instructors led to comparable learning outcomes, the effects were due to the dynamic interplay of information processing vs. attentional distraction. These findings reflect a benefit-cost trade-off where multimedia learning outcome is enhanced only when the cognitive benefits motivated by the social presence of onscreen instructor outweigh the cognitive costs brought about by concurrent attentional distraction unrelated to learning.


Assuntos
Aprendizagem , Multimídia , Humanos , Cognição/fisiologia , Memória de Curto Prazo/fisiologia , Estudantes
2.
PLoS Pathog ; 20(1): e1011934, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38206974

RESUMO

Epstein-Barr virus (EBV) is associated with several types of human cancer including nasopharyngeal carcinoma (NPC). The activation of EBV to the lytic cycle has been observed in advanced NPC and is believed to contribute to late-stage NPC development. However, how EBV lytic cycle promotes NPC progression remains elusive. Analysis of clinical NPC samples indicated that EBV reactivation and immunosuppression were found in advanced NPC samples, as well as abnormal angiogenesis and invasiveness. To investigate the role of the EBV lytic cycle in tumor development, we established a system that consists of two NPC cell lines, respectively, in EBV abortive lytic cycle and latency. In a comparative analysis using this system, we found that the NPC cell line in EBV abortive lytic cycle exhibited the superior chemotactic capacity to recruit monocytes and polarized their differentiation toward tumor-associated macrophage (TAM)-like phenotype and away from DCs, compared to EBV-negative or EBV-latency NPC cells. EBV-encoded transcription activator ZTA is responsible for regulating monocyte chemotaxis and TAM phenotype by up-regulating the expression of GM-CSF, IL-8, and GRO-α. As a result, TAM induced by EBV abortive lytic cycle promotes NPC angiogenesis, invasion, and migration. Overall, this study elucidated the role of the EBV lytic life cycle in the late development of NPC and revealed a mechanism underlying the ZTA-mediated establishment of the tumor microenvironment (TME) that promotes NPC late-stage progression.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/genética , Monócitos/metabolismo , Neoplasias Nasofaríngeas/genética , Microambiente Tumoral
3.
Proc Natl Acad Sci U S A ; 120(43): e2219491120, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37851678

RESUMO

In conventional superconductors, electron-phonon coupling plays a dominant role in generating superconductivity. In high-temperature cuprate superconductors, the existence of electron coupling with phonons and other boson modes and its role in producing high-temperature superconductivity remain unclear. The evidence of electron-boson coupling mainly comes from angle-resolved photoemission (ARPES) observations of [Formula: see text]70-meV nodal dispersion kink and [Formula: see text]40-meV antinodal kink. However, the reported results are sporadic and the nature of the involved bosons is still under debate. Here we report findings of ubiquitous two coexisting electron-mode couplings in cuprate superconductors. By taking ultrahigh-resolution laser-based ARPES measurements, we found that the electrons are coupled simultaneously with two sharp modes at [Formula: see text]70meV and [Formula: see text]40meV in different superconductors with different dopings, over the entire momentum space and at different temperatures above and below the superconducting transition temperature. These observations favor phonons as the origin of the modes coupled with electrons and the observed electron-mode couplings are unusual because the associated energy scales do not exhibit an obvious energy shift across the superconducting transition. We further find that the well-known "peak-dip-hump" structure, which has long been considered a hallmark of superconductivity, is also omnipresent and consists of "peak-double dip-double hump" finer structures that originate from electron coupling with two sharp modes. These results provide a unified picture for the [Formula: see text]70-meV and [Formula: see text]40-meV energy scales and their evolutions with momentum, doping and temperature. They provide key information to understand the origin of these energy scales and their role in generating anomalous normal state and high-temperature superconductivity.

4.
Proc Natl Acad Sci U S A ; 119(15): e2119429119, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35377791

RESUMO

Charge density waves (CDWs) have been observed in nearly all families of copper-oxide superconductors. But the behavior of these phases across different families has been perplexing. In La-based cuprates, the CDW wavevector is an increasing function of doping, exhibiting the so-called Yamada behavior, while in Y- and Bi-based materials the behavior is the opposite. Here, we report a combined resonant soft X-ray scattering (RSXS) and neutron scattering study of charge and spin density waves in isotopically enriched La1.8−xEu0.2SrxCuO4 over a range of doping 0.07≤x≤0.20. We find that the CDW amplitude is temperature independent and develops well above experimentally accessible temperatures. Further, the CDW wavevector shows a nonmonotonic temperature dependence, exhibiting Yamada behavior at low temperature with a sudden change occurring near the spin ordering temperature. We describe these observations using a Landau­Ginzburg theory for an incommensurate CDW in a metallic system with a finite charge compressibility and spin-CDW coupling. Extrapolating to high temperature, where the CDW amplitude is small and spin order is absent, our analysis predicts a decreasing wavevector with doping, similar to Y and Bi cuprates. Our study suggests that CDW order in all families of cuprates forms by a common mechanism.

5.
New Phytol ; 242(6): 2570-2585, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38708492

RESUMO

In plant species, anthocyanin accumulation is specifically regulated by light signaling. Although the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) complex is known to control anthocyanin biosynthesis in response to light, the precise mechanism underlying this process remains largely unknown. Here, we report that Increase in BONSAI Methylation 1 (IBM1), a JmjC domain-containing histone demethylase, participates in the regulation of light-induced anthocyanin biosynthesis in Arabidopsis. The expression of IBM1 was induced by high light (HL) stress, and loss-of-function mutations in IBM1 led to accelerated anthocyanin accumulation under HL conditions. We further identified that IBM1 is directly associated with SPA1/3/4 chromatin in vivo to establish a hypomethylation status on H3K9 and DNA non-CG at these loci under HL, thereby releasing their expression. Genetic analysis showed that quadruple mutants of IBM1 and SPA1/3/4 resemble spa134 mutants. Overexpression of SPA1 in ibm1 mutants complements the mutant phenotype. Our results elucidate the significance and mechanism of IBM1 histone demethylase in the epigenetic regulation of anthocyanin biosynthesis in Arabidopsis under HL conditions.


Assuntos
Antocianinas , Proteínas de Arabidopsis , Arabidopsis , Epigênese Genética , Regulação da Expressão Gênica de Plantas , Histona Desmetilases com o Domínio Jumonji , Luz , Mutação , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Antocianinas/biossíntese , Antocianinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Mutação/genética , Cromatina/metabolismo , Metilação de DNA/genética , Histonas/metabolismo , Fenótipo
6.
Nano Lett ; 23(12): 5625-5633, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37310876

RESUMO

Kagome superconductors AV3Sb5 (A = K, Rb, Cs) provide a fertile playground for studying intriguing phenomena, including nontrivial band topology, superconductivity, giant anomalous Hall effect, and charge density wave (CDW). Recently, a C2 symmetric nematic phase prior to the superconducting state in AV3Sb5 drew enormous attention due to its potential inheritance of the symmetry of the unusual superconductivity. However, direct evidence of the rotation symmetry breaking of the electronic structure in the CDW state from the reciprocal space is still rare, and the underlying mechanism remains ambiguous. The observation shows unconventional unidirectionality, indicative of rotation symmetry breaking from six-fold to two-fold. The interlayer coupling between adjacent planes with π-phase offset in the 2 × 2 × 2 CDW phase leads to the preferred two-fold symmetric electronic structure. These rarely observed unidirectional back-folded bands in KV3Sb5 may provide important insights into its peculiar charge order and superconductivity.

7.
Phys Rev Lett ; 131(11): 116002, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37774302

RESUMO

The extremely overdoped cuprates are generally considered to be Fermi liquid metals without exotic orders, whereas the underdoped cuprates harbor intertwined states. Contrary to this conventional wisdom, using Cu L_{3}-edge and O K-edge resonant x-ray scattering, we reveal a charge order (CO) correlation in overdoped La_{2-x}Sr_{x}CuO_{4} (0.35≤x≤0.6) beyond the superconducting dome. This CO has a periodicity of ∼6 lattice units with correlation lengths of ∼20 lattice units. It shows similar in-plane momentum and polarization dependence and dispersive excitations as the CO of underdoped cuprates, but its maximum intensity differs along the c direction and persists up to 300 K. This CO correlation cannot be explained by the Fermi surface instability and its origin remains to be understood. Our results suggest that CO is prevailing in the overdoped metallic regime and requires a reassessment of the picture of overdoped cuprates as weakly correlated Fermi liquids.

8.
Phys Rev Lett ; 131(2): 026701, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37505968

RESUMO

In kagome metal CsV_{3}Sb_{5}, multiple intertwined orders are accompanied by both electronic and structural instabilities. These exotic orders have attracted much recent attention, but their origins remain elusive. The newly discovered CsTi_{3}Bi_{5} is a Ti-based kagome metal to parallel CsV_{3}Sb_{5}. Here, we report angle-resolved photoemission experiments and first-principles calculations on pristine and Cs-doped CsTi_{3}Bi_{5} samples. Our results reveal that the van Hove singularity (vHS) in CsTi_{3}Bi_{5} can be tuned in a large energy range without structural instability, different from that in CsV_{3}Sb_{5}. As such, CsTi_{3}Bi_{5} provides a complementary platform to disentangle and investigate the electronic instability with a tunable vHS in kagome metals.

9.
Langmuir ; 39(20): 6947-6956, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37172292

RESUMO

Poly(ε-caprolactone) (PCL)-incorporated lignin-chitosan biomass-based nanocomposite porous scaffolds have been effectively prepared by templating oil-in-water Pickering high internal phase emulsions (HIPEs). PCL is dissolved in oil and chitosan and lignin nanoparticles originate in water. The continuous phase of the emulsions is gelled by cross-linking of chitosan with genipin and then freeze-dried to obtain porous scaffolds. The resulting scaffolds display interconnected and tunable pore structures. An increase in PCL content increases the mechanical strength and greatly reduces the water absorption capacity of the scaffolds. Scaffolds loaded with the anti-bacterial drug enrofloxacin show a slow drug release profile, adjustable release rate, and favorable long-term anti-bacterial activity. Moreover, Pickering emulsion templates with suitable viscosity are used as 3D printing inks to construct porous scaffolds with personalized geometry. The results imply that the simplicity and versatility of the technique of combining freeze-drying with Pickering HIPE templates is a promising approach to fabricate hydrophobic biopolymer-incorporated biomass-based nanocomposite porous scaffolds for biomedical applications.

10.
J Nanobiotechnology ; 20(1): 239, 2022 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-35597946

RESUMO

High-quality cutaneous wound healing is associated with rapid wound closure and a comfortable healing process. Currently, exosomes derived from mesenchymal stem cells displayed a prominent therapeutic effect on skin wound closure. But the therapeutic approaches for wound itching are very limited in clinical. Stem cells from human exfoliated deciduous teeth (SHED) may offer a unique exosome resource for cell-free therapeutics in potential clinical applications. Here, we investigated the common mechanisms underlying wound closure and unpleasant sensation of itching, focusing on the contribution of the SHED-derived exosome to immune response and wound itching during healing. The effects of SHED-derived exosomes on inflammatory wound healing were examined using lipopolysaccharide (LPS)-induced wounds in a mouse model. We found prolonged inflammation and distinct itch responses in skin wound tissue during LPS-induced wound healing. SHED-derived exosomes facilitated LPS-induced wound closure and relieved wound itching. Therefore, they are ideal for the treatment of wound healing. Macrophages in skin wound tissues are responsible for autophagy during wound healing. Macrophage autophagy also regulates cell proliferation, migration, and neuronal signal transduction in vitro. SHED-derived exosomes containing miR-1246 enhanced autophagy by regulating macrophage function through the AKT, ERK1/2, and STAT3 signaling pathways. Thus, SHED-derived exosomes promote wound healing with less itching in an LPS-induced wound model by stimulating macrophage autophagy, which has implications for the treatment of inflammatory wound healing.


Assuntos
Exossomos , Animais , Autofagia , Exossomos/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos , Camundongos , Prurido/metabolismo , Cicatrização
11.
Strahlenther Onkol ; 197(3): 177-187, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32488293

RESUMO

OBJECTIVE: This study aimed to evaluate the quality of locally advanced nasopharyngeal carcinoma (NPC) radiotherapy plans generated by the automated planning module of a commercial treatment planning system (TPS). METHODS: Data of 30 patients with locally advanced NPC were retrospectively investigated. For each patient, volumetric modulated arc therapy (VMAT) plans with double arcs were generated manually by experienced physicists and automatically in the Pinnacle3 Auto-Planning module (Philips Medical Systems, Fitchburg, WI, USA). The anatomic distance between the second clinical target volume (CTV2) and the pons of the brainstem, and the T category of disease were factored into the evaluation. Dosimetric verification was evaluated in terms of gamma pass rate. Target coverage, sparing of organs at risk (OARs), and monitor units were evaluated and compared between the manual and automatic VMAT plans. RESULTS: Not all treatment plans fully met the dose objectives for planning target volumes (PTVs) and OARs, particularly in T4 patients. Overall, automatic VMAT provides a comparable or superior plan quality to manual VMAT in most cases. In stratified analysis, plan quality is mainly independent on T category but is also affected by anatomic distance. If the anatomic distance is less than 5 mm, the automatic VMAT plan quality is equal or even inferior to manual VMAT performed by experienced physicists. Conversely, if the anatomic distance is greater than 5 mm, the automatic VMAT plan quality is superior to manual VMAT. Gamma pass rates for quality assurance are similar between manual and automatic VMAT plans for the former case, but significantly higher in automatic VMAT for the latter. CONCLUSION: The selection of manual versus automatic VMAT planning in locally advanced NPC should be made individually based on the anatomic distance, rather than blindly and habitually, since automatic VMAT is not good enough to completely replace manual VMAT.


Assuntos
Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Estudos Retrospectivos
12.
Zhongguo Zhong Yao Za Zhi ; 46(10): 2578-2587, 2021 May.
Artigo em Zh | MEDLINE | ID: mdl-34047106

RESUMO

To systematically evaluate the clinical efficacy and safety of Compound Danshen Dripping Pills combined with conventional antihypertensive drugs in the treatment of hypertensive left ventricular hypertrophy. China National Knowledge Infrastructure(CNKI), Wanfang, VIP, PubMed, EMbase, Cochrane Library, Ovid and Web of Science databases were searched by computer to retrieve the randomized controlled trials(RCTs) of Compound Danshen Dripping Pills combined with conventional antihypertensive drugs in the treatment of hypertensive left ventricular hypertrophy from the establishment of databases to July 2020. After two researchers performed data retrieval, data extraction, and risk assessment of bias, they used RevMan 5.3 software for Meta-analysis. A total of 10 RCTs were included, with a total of 979 patients. Meta-analysis results showed that in terms of interventricular septal thickness(MD=-0.70, 95%CI[-1.15,-0.24], P=0.003), left ventricular posterior wall thickness(MD=-0.81, 95%CI[-1.41,-0.21], P=0.008), left ventricular mass index(MD=-8.75, 95%CI[-17.40,-0.10], P=0.05), systolic blood pressure(MD=-8.97, 95%CI[-13.46,-4.48], P<0.000 1), diastolic blood pressure(MD=-5.87, 95%CI[-8.39,-3.34], P<0.000 01) and left ventricular end-diastolic diameter(MD=-1.73, 95%CI[-2.38,-1.08], P<0.000 01), Compound Danshen Dripping Pills combined with conventional antihypertensive drugs was superior to conventional antihypertensive drugs. In terms of left ventricular ejection fraction(MD=0.41, 95%CI[-0.74, 1.55], P=0.49), there was no statistical difference in treatment between the two groups. Because of the small amount of literatures included in the safety aspect, it is impossible to give an accurate conclusion. The GRADE score showed that the level of evidence was low and extremely low. The results show that the Compound Danshen Dripping Pills combined with conventional antihypertensive drugs may effectively improve the clinical efficacy for hypertensive ventricular hypertrophy, and the safety needs to be further explored. Due to the low quality of the included literatures, more high-quality RCTs are needed for verification.


Assuntos
Anti-Hipertensivos , Medicamentos de Ervas Chinesas , Anti-Hipertensivos/efeitos adversos , Canfanos , China , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Panax notoginseng , Salvia miltiorrhiza , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
13.
BMC Health Serv Res ; 20(1): 430, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32423447

RESUMO

BACKGROUND: To tackle the issue with the low usage of primary healthcare service in China, it is essential to align resource distribution with the preferences of the community residents. There are few academic researches for describing residents' perceived characteristics of healthcare services in China. This study aims to investigate the preferences of healthcare services utilization in community residents and explore the heterogeneity. The findings will be useful for the policy makers to take targeted measures to tailor the provision of healthcare services. METHODS: The face-to-face interviews and surveys were conducted to elicit four key attributes (care provider; mode of services; cost; travel time) of the preference from community residents for healthcare utilization. A rational test was presented first to confirm the consistency, and then 16 pairs of choice tasks with 12 sociodemographic items were given to the respondents. Two hypothetical options for each set, without an opt-out option, were presented in each choice task. The latent class analysis (LCA) was used to analyse the data. RESULTS: Two thousand one hundred sixty respondents from 36 communities in 6 cities were recruited for our study. 2019 (93.47%) respondents completed valid discrete choice experiment (DCE) questionnaires. The LCA results suggested that four groups of similar preferences were identified. The first group (27.29%) labelled as "Comprehensive consideration" had an even preference of all four attributes. The second group (37.79%) labelled as "Price-driven" preferred low-price healthcare services. The third group labelled as "Near distance" showed a clear preference for seeking healthcare services nearby. The fourth group (34.18%) labelled as "Quality seeker" preferred the healthcare service provided by experts. Willingness to pay (WTP) results showed that people were willing to accept CNY202.12($29.37) for Traditional Chinese Medicine (TCM) services and willing to pay CNY604.31($87.81) for the service provided by experts. CONCLUSIONS: Our study qualitatively measures the distinct preferences for healthcare utilization in community residents in China. The results suggest that the care provider, mode of services, travel time and cost should be considered in priority setting decisions. The study, however, reveals substantial disagreement in opinion of TCM between different population subgroups.


Assuntos
Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Preferência do Paciente/estatística & dados numéricos , Adolescente , Adulto , China , Comportamento de Escolha , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Adulto Jovem
14.
Proc Natl Acad Sci U S A ; 111(52): 18501-6, 2014 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-25502774

RESUMO

In high-temperature cuprate superconductors, it is now generally agreed that superconductivity is realized by doping an antiferromagnetic Mott (charge transfer) insulator. The doping-induced insulator-to-superconductor transition has been widely observed in cuprates, which provides important information for understanding the superconductivity mechanism. In the iron-based superconductors, however, the parent compound is mostly antiferromagnetic bad metal, raising a debate on whether an appropriate starting point should go with an itinerant picture or a localized picture. No evidence of doping-induced insulator-superconductor transition (or crossover) has been reported in the iron-based compounds so far. Here, we report an electronic evidence of an insulator-superconductor crossover observed in the single-layer FeSe film grown on a SrTiO3 substrate. By taking angle-resolved photoemission measurements on the electronic structure and energy gap, we have identified a clear evolution of an insulator to a superconductor with increasing carrier concentration. In particular, the insulator-superconductor crossover in FeSe/SrTiO3 film exhibits similar behaviors to that observed in the cuprate superconductors. Our results suggest that the observed insulator-superconductor crossover may be associated with the two-dimensionality that enhances electron localization or correlation. The reduced dimensionality and the interfacial effect provide a new pathway in searching for new phenomena and novel superconductors with a high transition temperature.

15.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 42(4): 457-462, 2017 Apr 28.
Artigo em Zh | MEDLINE | ID: mdl-28490706

RESUMO

Many risk factors lead to hypohepatia and hepatic failure, causing people suffering from end-stage liver disease. The conventional treatment for end-stage liver disease is not good enough. Orthotopic liver transplantation is effective. However, the high cost, lack of liver source, immune rejection and other factors limit the large-scale clinical application. Thus, cell therapy is a good option. Studies on common cell sources for the treatment of liver disease and the induction of hepatocytes by embryonic stem cells or pluripotent stem cells have made progress. With the development of stem cell technology, cell transplantation has become a new option, which brings hope to people with end-stage liver diseasetransplantation has become a new option. It brings hope to people with end-stage liver disease.


Assuntos
Células-Tronco Embrionárias/transplante , Doença Hepática Terminal/terapia , Células-Tronco Pluripotentes/transplante , Transplante de Células-Tronco/tendências , Terapia Baseada em Transplante de Células e Tecidos , Terapia Genética , Hepatócitos , Humanos , Fígado/crescimento & desenvolvimento
16.
Proc Natl Acad Sci U S A ; 109(10): 3694-8, 2012 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-22355146

RESUMO

The physical property investigation (like transport measurements) and ultimate application of the topological insulators usually involve surfaces that are exposed to ambient environment (1 atm and room temperature). One critical issue is how the topological surface state will behave under such ambient conditions. We report high resolution angle-resolved photoemission measurements to directly probe the surface state of the prototypical topological insulators, Bi(2)Se(3) and Bi(2)Te(3), upon exposing to various environments. We find that the topological order is robust even when the surface is exposed to air at room temperature. However, the surface state is strongly modified after such an exposure. Particularly, we have observed the formation of two-dimensional quantum well states near the exposed surface of the topological insulators. These findings provide key information in understanding the surface properties of the topological insulators under ambient environment and in engineering the topological surface state for applications.


Assuntos
Física/métodos , Bismuto/química , Elétrons , Meio Ambiente , Lasers , Teste de Materiais , Teoria Quântica , Selênio/química , Propriedades de Superfície , Telúrio/química , Temperatura , Difração de Raios X
17.
Nat Mater ; 12(7): 605-10, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23708329

RESUMO

The recent discovery of possible high-temperature superconductivity in single-layer FeSe films has generated significant experimental and theoretical interest. In both the cuprate and the iron-based high-temperature superconductors, superconductivity is induced by doping charge carriers into the parent compound to suppress the antiferromagnetic state. It is therefore important to establish whether the superconductivity observed in the single-layer sheets of FeSe--the essential building blocks of the Fe-based superconductors--is realized by undergoing a similar transition. Here we report the phase diagram for an FeSe monolayer grown on a SrTiO3 substrate, by tuning the charge carrier concentration over a wide range through an extensive annealing procedure. We identify two distinct phases that compete during the annealing process: the electronic structure of the phase at low doping (N phase) bears a clear resemblance to the antiferromagnetic parent compound of the Fe-based superconductors, whereas the superconducting phase (S phase) emerges with the increase in doping and the suppression of the N phase. By optimizing the carrier concentration, we observe strong indications of superconductivity with a transition temperature of 65±5 K. The wide tunability of the system across different phases makes the FeSe monolayer ideal for investigating not only the physics of superconductivity, but also for studying novel quantum phenomena more generally.

18.
Acta Neurol Belg ; 124(3): 879-885, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38286872

RESUMO

BACKGROUND: Identifying reliable biomarkers for early detection and prediction of cognitive impairment in Parkinson's disease (PD) is crucial for optimal patient care. This study set out to investigate the potential of YWHAG as a diagnostic biomarker for cognitive impairment in PD. METHODS: We enrolled a total of 331 PD patients and selected 241 patients that met the criteria for cognitive impairment analysis. The patients were classified into three groups: PD-NC: PD patients with normal cognition, PD-MCI: PD patients with mild cognitive impairment, and PD-D: PD patients with dementia. ELISA was employed to assess YWHAG expression, as well as the neurofilament light chain (NfL). Additionally, cognitive impairment was evaluated using MoCA scores. Correlation analysis and receiver operating curve analysis (ROC) were performed to clarify the relationship between YWHAG expression and cognitive impairment. RESULTS: Our findings revealed a significant upregulation of YWHAG expression in both the PD-MCI and PD-D groups compared to the PD-NC group. This observation aligned with the elevated expression of NfL in the PD-MCI and PD-D groups. YWHAG and NfL expression levels displayed negative correlations with MoCA scores and positive associations with age. Furthermore, ROC curve analysis demonstrated the diagnostic efficacy of YWHAG expression in distinguishing individuals with PD-NC, PD-MCI, and PD-D. CONCLUSIONS: Our findings indicate that YWHAG could serve as a promising biomarker for cognitive impairment in PD. The upregulation of YWHAG expression in PD-MCI and PD-D groups, its association with cognitive impairment, and its correlations with MoCA scores and NfL levels support its potential clinical utility.


Assuntos
Biomarcadores , Disfunção Cognitiva , Doença de Parkinson , Humanos , Doença de Parkinson/sangue , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico , Feminino , Masculino , Disfunção Cognitiva/sangue , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Idoso , Biomarcadores/sangue , Pessoa de Meia-Idade , Proteínas de Neurofilamentos/sangue , Idoso de 80 Anos ou mais , Curva ROC
19.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1869(6): 159498, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38703945

RESUMO

The biosynthetic capability of the long-chain polyunsaturated fatty acids (LC-PUFA) in teleosts are highly diversified due to evolutionary events such as gene loss and subsequent neo- and/or sub-functionalisation of enzymes encoded by existing genes. In the present study, we have comprehensively characterised genes potentially involved in LC-PUFA biosynthesis, namely one front-end desaturase (fads2) and eight fatty acid elongases (elovl1a, elovl1b, elovl4a, elovl4b, elovl5, elovl7, elovl8a and elovl8b) from an amphidromous teleost, Ayu sweetfish, Plecoglossus altivelis. Functional analysis confirmed Fads2 with Δ6, Δ5 and Δ8 desaturase activities towards multiple PUFA substrates and several Elovl enzymes exhibited elongation capacities towards C18-20 or C18-22 PUFA substrates. Consequently, P. altivelis possesses a complete enzymatic capability to synthesise physiologically important LC-PUFA including arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) from their C18 precursors. Interestingly, the loss of elovl2 gene in P. altivelis was corroborated by genomic and phylogenetic analyses. However, this constraint would possibly be overcome by the function of alternative Elovl enzymes, such as Elovl1b, which has not hitherto been functionally characterised in teleosts. The present study contributes novel insights into LC-PUFA biosynthesis in the relatively understudied teleost group, Osmeriformes (Stomiati), thereby enhancing our understanding of the complement of LC-PUFA biosynthetic genes within teleosts.


Assuntos
Ácidos Graxos Dessaturases , Elongases de Ácidos Graxos , Ácidos Graxos Insaturados , Osmeriformes , Animais , Ácidos Graxos Insaturados/metabolismo , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/genética , Osmeriformes/metabolismo , Osmeriformes/genética , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Dessaturases/genética , Elongases de Ácidos Graxos/metabolismo , Elongases de Ácidos Graxos/genética , Filogenia , Proteínas de Peixes/metabolismo , Proteínas de Peixes/genética , Vias Biossintéticas/genética , Acetiltransferases/metabolismo , Acetiltransferases/genética
20.
ACS Nano ; 18(5): 4456-4466, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38276073

RESUMO

Metal halide perovskites offer ample opportunities to develop advanced optoelectronic devices. This work showcases that the integration of metal halide perovskites into metal oxide nanoshells with controllable interior cavities can enable water-vapor-responsive dual-mode switching of fluorescence and structural color. Through a ship-in-a-bottle method to introduce a controlled amount of CsPbBr3 into MnO2 nanoshells, we have designed CsPbBr3@MnO2 yolk-shell nanostructures, which can uptake a defined amount of water to exhibit rapid (less than 1 s) and reversible (≥100 cycles) responses in both fluorescence on-off and color change when exposed to dynamic water vapor. These responses originate from the water-triggered phase transformation of CsPbBr3 to CsPb2Br5 and the structural color change of the MnO2 shell. The altered electronic and bonding structure at the oxide-halide interface, rapid water accumulation in the yolk-shell cavity, and protective effect of the oxide shell facilitate the reversible transformations. The response characteristics of the yolk-shell nanostructures have been further demonstrated in fabricating patterned films capable of multiple fluorescence/structural color responses, highlighting their potential for applications in advanced anticounterfeiting and encryption.

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