Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Nano Lett ; 23(11): 5334-5341, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37205726

RESUMO

Interest in ZrTe5 has been reinvigorated in recent years owing to its potential for hosting versatile topological electronic states and intriguing experimental discoveries. However, the mechanism of many of its unusual transport behaviors remains controversial: for example, the characteristic peak in the temperature-dependent resistivity and the anomalous Hall effect. Here, through employing a clean dry-transfer fabrication method in an inert environment, we successfully obtain high-quality ZrTe5 thin devices that exhibit clear dual-gate tunability and ambipolar field effects. Such devices allow us to systematically study the resistance peak as well as the Hall effect at various doping densities and temperatures, revealing the contribution from electron-hole asymmetry and multiple-carrier transport. By comparing with theoretical calculations, we suggest a simplified semiclassical two-band model to explain the experimental observations. Our work helps to resolve the longstanding puzzles on ZrTe5 and could potentially pave the way for realizing novel topological states in the two-dimensional limit.

2.
Oxid Med Cell Longev ; 2021: 6966394, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34795842

RESUMO

Subarachnoid hemorrhage (SAH) is a cerebrovascular disease associated with high morbidity and mortality. CXCR4 provides neuroprotective effects, which can alleviate brain injury and inflammation induced by stroke. Previous studies have suggested that CXCR4 reduces the pyroptosis of LPS-stimulated BV2 cells. The purpose of this study was to evaluate the antipyroptosis effects and mechanisms of CXCR4 after SAH. SAH animal model was induced via endovascular perforation. A total of 136 male Sprague-Dawley rats were used. Recombinant human cysteine-X-cysteine chemokine ligand 12 (rh-CXCL-12) was administered intranasally at 1 h after SAH induction. To investigate the underlying mechanism, the inhibitor of CXCR4, AMD3100, was administered intraperitoneally at 1 h before SAH. The neurobehavior tests were assessed, followed by performing Western blot and immunofluorescence staining. The Western blot results suggested that the expressions of endogenous CXCL-12, CXCR4, and NLRP1 were increased and peaked at 24 h following SAH. Immunofluorescence staining showed that CXCR4 was expressed on neurons, microglia, and astrocytes. Rh-CXCL-12 treatment improved the neurological deficits and reduced the number of FJC-positive cells, IL-18-positive neurons, and cleaved caspase-1(CC-1)-positive neurons after SAH. Meanwhile, rh-CXCL-12 treatment increased the levels of CXCL-12 and CXCR4, and reduced the levels of NLRP1, IL-18, IL-1ß, and CC-1. Moreover, the administration of AMD3100 abolished antipyroptosis effects of CXCL-12 and its regulation of CXCR4 post-SAH. The CXCR4/NLRP1 signaling pathway may be involved in CXCL-12-mediated neuronal pyroptosis after SAH. Early administration of CXCL-12 may be a preventive and therapeutic strategy against brain injury after SAH.


Assuntos
Lesões Encefálicas/prevenção & controle , Quimiocina CXCL12/administração & dosagem , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Piroptose , Receptores CXCR4/metabolismo , Hemorragia Subaracnóidea/complicações , Animais , Lesões Encefálicas/etiologia , Lesões Encefálicas/metabolismo , Lesões Encefálicas/patologia , Quimiocina CXCL12/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Inflamação/etiologia , Inflamação/metabolismo , Inflamação/patologia , Inflamação/prevenção & controle , Masculino , Proteínas do Tecido Nervoso/genética , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Receptores CXCR4/genética , Transdução de Sinais
3.
Sensors (Basel) ; 20(5)2020 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-32121445

RESUMO

The proper utilization of road information can improve the performance of relay-node selection methods. However, the existing schemes are only applicable to a specific road structure, and this limits their application in real-world scenarios where mostly more than one road structure exists in the Region of Interest (RoI), even in the communication range of a sender. In this paper, we propose an adaptive relay-node selection (ARNS) method based on the exponential partition to implement message broadcasting in complex scenarios. First, we improved a relay-node selection method in the curved road scenarios through the re-definition of the optimal position considering the distribution of the obstacles. Then, we proposed a criterion of classifying road structures based on their broadcast characteristics. Finally, ARNS is designed to adaptively apply the appropriate relay-node selection method based on the exponential partition in realistic scenarios. Simulation results on a real-world map show that the end-to-end broadcast delay of ARNS is reduced by at least 13.8% compared to the beacon-based relay-node selection method, and at least 14.0% compared to the trinary partitioned black-burst-based broadcast protocol (3P3B)-based relay-node selection method. The broadcast coverage is increased by 3.6-7% in curved road scenarios, with obstacles benefitting from the consideration of the distribution of obstacles. Moreover, ARNS achieves a higher and more stable packet delivery ratio (PDR) than existing methods profiting from the adaptive selection mechanism.

4.
Int J Psychol ; 51(2): 156-62, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25622795

RESUMO

In this study, a priming Stroop paradigm was used to determine whether stereotype activation is unintentional. Priming conditions (priming/no-priming) and the relationship between priming and target (consistent/inconsistent/no-relation) were the independent variables; accuracy, reaction time and N400 amplitude were used as dependent variables. The reaction time revealed that stereotype activation is, to some extent, unintentional. Furthermore, the event-related potenial (ERP) results showed that N400 amplitude was larger for inconsistent conditions than for consistent conditions. This result supported the notion that stereotype activation is an unintentional and automatic process.


Assuntos
Comportamento , Potenciais Evocados , Estereotipagem , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
5.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 32(1): 99-103, 2007 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-17344596

RESUMO

OBJECTIVE: To determine the effect of tanshinone IIA on the growth and apoptosis in human hepatoma cell line HepG2. METHODS: The human hepatoma cell line HepG2 was treated with tanshinone IIA at various concentrations for 72 h. The inhibition of proliferation was measured by MTT assay and apoptosis-related alterations in morphology measured by cytochemical staining (HT33258). DNA fragmentation was evaluated by agarose gel electrophoresis. Apoptotic rate and cell arrest were quantified by flow cytometry (FCM). RESULTS: Tanshinone IIA inhibited the growth of HepG2 in a time- and dose- dependent manner. The semi-inhibitory concentration (IC50) value after the treatment with tanshinone IIA on HepG2 for 24, 48 and 72 h were 14.7, 7.4, and 3.9 microg/ mL, respectively. After the treatment with 0.5 - 10 microg/mL tanshinone IIA for 72 h, the formation of apoptotic bodies was observed. DNA ladder was shown in agarose gel electrophoresis, in addition to the cells treated by 1.0 microg/mL tanshinone IIA . The apoptotic rates at 0.5, 1.0, 2.0, 5.0, and 10.0 microg/mL for 72 h were 20.32%+/-2.16%, 28.0%+/-2.35%, 33.87%+/-3.43%, 46.73%+/-4.08% and 57.85%+/-3.74%, respectively, which were all significantly higher than those of the control group (P<0.05). CONCLUSION: Tanshinone IIA can inhibit the proliferation of human hepatoma cell line HepG2 in a time- and dose- dependent manner, and the mechanism of growth inhibition of human hepatoma cells may be related to the induction of apoptosis.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fenantrenos/farmacologia , Abietanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Citometria de Fluxo , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Microscopia de Fluorescência , Fatores de Tempo
6.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 30(3): 315-7, 2005 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-16045022

RESUMO

OBJECTIVE: To explore the levels of sex hormones in female patients with systemic lupus erythematosus (SLE) and its role in the genesis of SLE. METHODS: The serum levels of estradiol, estriol, testosterone, progesterone, and prolactin were determined by electro-chemiluminescence immunoassay in 98 female patients with SLE and compared with those of 38 healthy women. RESULTS: The serum levels of estradiol, estriol, progesterone, and prolactin were significantly higher than those in the healthy women (P <0.05). The serum levels of estradiol, progesterone, and prolactin in patients with SLE in 25 to 34 year old group were higher than the other age groups and the control group (P < 0.05), and the serum levels of estradiol and prolactin in patients with active phase of SLE were significantly higher than those in patients with stable phase of SLE (P <0.05). CONCLUSION: The levels of sex hormones have a close corretation with the genesis and development of SLE.


Assuntos
Hormônios Esteroides Gonadais/sangue , Lúpus Eritematoso Sistêmico/sangue , Adolescente , Adulto , Estradiol/sangue , Estriol/sangue , Feminino , Humanos , Lúpus Eritematoso Sistêmico/etiologia , Pessoa de Meia-Idade , Progesterona/sangue , Prolactina/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA