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1.
Small ; 20(1): e2305200, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37649150

RESUMO

Artificially molding exciton flux is the cornerstone for developing promising excitonic devices. In the emerging hetero/homobilayers, the spatial separated charges prolong exciton lifetimes and create out-plane dipoles, facilitating electrically control exciton flux on a large scale, and the nanoscale periodic moiré potentials arising from twist-angle or/and lattice mismatch can substantially alter exciton dynamics, which are mainly proved in the heterostructures. However, the spatially indirect excitons dynamics in homobilayers without lattice mismatch remain elusive. Here the nonequilibrium dynamics of indirect exciton in homobilayers are systematically investigated. The homobilayers with slightly twist-angle can induce a deep moiré potential (>50 meV) in the energy landscape of indirect excitons, resulting in a strongly localized moiré excitons insulating the transport dynamics from phonons and disorder. These findings provide insights into the exciton dynamics and many-body physics in moiré superlattices modulated energy landscape, with implications for designing excitonic devices operating at room temperature.

2.
Opt Express ; 31(6): 9224-9235, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37157496

RESUMO

This paper reports a multi-functional terahertz (THz) metamaterial based on a nano-imprinting method. The metamaterial is composed of four layers: 4 L resonant layer, dielectric layer, frequency selective layer, and dielectric layer. The 4 L resonant structure can achieve broadband absorption, while the frequency selective layer can achieve transmission of specific band. The nano-imprinting method combines electroplating of nickel mold and printing of silver nano-particle ink. Using this method, the multilayer metamaterial structures can be fabricated on ultrathin flexible substrates to achieve visible light transparency. For verification, a THz metamaterial with broadband absorption in low frequency and efficient transmission in high frequency is designed and printed. The sample's thickness is about 200 µm and area is 65 × 65 mm2. Moreover, a fiber-based multi-mode terahertz time-domain spectroscopy system was built to test its transmission and reflection spectra. The results are consistent with the expectations.

3.
Phytochem Anal ; 33(2): 239-248, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34390060

RESUMO

INTRODUCTION: The roots of Stephania succifera are used in traditional medicine for the treatment of several diseases. Research on this plant has mainly focused on bioactive alkaloids from the roots, and no previous work on compounds from the abundant leaves has yet been reported. OBJECTIVE: To identify and compare alkaloidal compounds in S. succifera roots and leaves and to predict the potential bioactivity of some alkaloids. METHODS: High-performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS/MS) was employed to identify alkaloidal compounds from S. succifera. The potential targets and bioactivities of most alkaloids were predicted using the PharmMapper server. RESULTS: Fifty-six alkaloidal compounds, including protoberberine-, aporphine-, proaporphine-, benzylisoquinoline-, and lactam-type alkaloids, were identified or tentatively identified in S. succifera roots and leaves based on the HPLC-MS data. Forty-one compounds have not been previously reported in S. succifera and eight of them have not been previously reported in the literature. Twenty-four alkaloidal compounds were found in both roots and leaves. Twelve potential targets with different indications were predicted for some alkaloids. CONCLUSION: Comparison of chemical constituents and their potential bioactivities for S. succifera roots and leaves indicated that diverse bioactive alkaloids were present in the leaves as well as the roots. PharmMapper provided new directions for bioactivity screening. This study will be helpful for further understanding the medicinal components of S. succifera and the rational utilisation of plant resources.


Assuntos
Alcaloides , Stephania , Alcaloides/análise , Cromatografia Líquida de Alta Pressão/métodos , Extratos Vegetais/química , Folhas de Planta/química , Stephania/química , Espectrometria de Massas em Tandem/métodos
4.
Sensors (Basel) ; 22(18)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36146424

RESUMO

Femtosecond laser filamentation is a unique nonlinear optical phenomenon when high-power ultrafast laser propagation in all transparent optical media. During filamentation in the atmosphere, the ultrastrong field of 1013-1014 W/cm2 with a large distance ranging from meter to kilometers can effectively ionize, break, and excite the molecules and fragments, resulting in characteristic fingerprint emissions, which provide a great opportunity for investigating strong-field molecules interaction in complicated environments, especially remote sensing. Additionally, the ultrastrong intensity inside the filament can damage almost all the detectors and ignite various intricate higher order nonlinear optical effects. These extreme physical conditions and complicated phenomena make the sensing and controlling of filamentation challenging. This paper mainly focuses on recent research advances in sensing with femtosecond laser filamentation, including fundamental physics, sensing and manipulating methods, typical filament-based sensing techniques and application scenarios, opportunities, and challenges toward the filament-based remote sensing under different complicated conditions.

5.
Neurotherapeutics ; 21(4): e00353, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575503

RESUMO

Driven by the scarcity of effective treatment options in clinical settings, the present study aimed to identify a new potential target for Alzheimer's disease (AD) treatment. We focused on Lars2, an enzyme synthesizing mitochondrial leucyl-tRNA, and its role in maintaining mitochondrial function. Bioinformatics analysis of human brain transcriptome data revealed downregulation of Lars2 in AD patients compared to healthy controls. During in vitro experiments, the knockdown of Lars2 in mouse neuroblastoma cells (neuro-2a cells) and primary cortical neurons led to morphological changes and decreased density in mouse hippocampal neurons. To explore the underlying mechanisms, we investigated how downregulated Lars2 expression could impede the phosphatidylinositol 3-kinase/protein kinase B (PI3K-AKT) pathway, thereby mitigating AKT's inhibitory effect on glycogen synthase kinase 3 beta (GSK3ß). This led to the activation of GSK3ß, causing excessive phosphorylation of Tau protein and subsequent neuronal degeneration. During in vivo experiments, knockout of lars2 in hippocampal neurons confirmed cognitive impairment through the Barnes maze test, the novel object recognition test, and nest-building experiments. Additionally, immunofluorescence assays indicated an increase in p-tau, atrophy in the hippocampal region, and a decrease in neurons following Lars2 knockout. Taken together, our findings indicate that Lars2 represents a promising therapeutic target for AD.

6.
Ying Yong Sheng Tai Xue Bao ; 35(2): 480-488, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38523106

RESUMO

The construction of urban ecological green wedges, which can mitigate the heat island effect through cooling and ventilation effects, is an important way to enhance the adaptation of cities to climate change. Dynamic monitoring and periodic assessment of both the conservation status and cooling effect of ecological green wedges is a key to ensure the heat mitigation benefits. Based on multi-source remote sensing data, we systematically analyzed the land use changes of six ecological green wedges in Wuhan in 2013 and 2020 using the methods of Markov transfer matrix, land use dynamics, and comprehensive index of land use degree, and evaluated the changes in surface temperature of the ecological green wedges and their cooling island effect. Results showed that the ecological green wedges in Wuhan generally had a large amount of construction land encroaching on ecological land from 2013 to 2020, with the water decreased the most. With the continuous deterioration of ecological green wedges, their land surface temperatures showed rising trends, together with significant weakening trends in cooling island effects. Among all the six wedges, the Dadonghu, Tangxun, and Wuhu exhibited relatively better ecological conservation, slighter land use change and lower overall development degree. Qinglinghu and Houguanhu demonstrated average levels of conservation. Fuhe experienced the most severe change under the significant influence of the westward policy of Wuhan City, with the proportion of water decreasing by 7.1%, warming up by 3.00 ℃, and the largest reduction in cooling distance for the cooling island effect, amounting to about 210 m. The results provided scientific evidence for the urban heat island mitigation-oriented planning and management of ecological green wedges for Wuhan City.


Assuntos
Temperatura Alta , Água , Cidades , Temperatura , China , Monitoramento Ambiental/métodos
7.
Clin Exp Med ; 23(1): 65-78, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35103883

RESUMO

BACKGROUND AND AIMS: Several malignant solid tumors have been reported to have an abnormal expression of the long non-coding RNA CASC15 (lncRNA CASC15). However, the clinicopathologic and prognostic importance of CASC15 in solid tumors are unknown. As a result, we examined the interrelationship between CASC15, overall survival length, and clinicopathological attributes of cancers affecting humans by analyzing various studies and The Cancer Genome Atlas (TCGA) data related to CASC15 expression. METHODS: Web of Science, PubMed, Cochrane Library, Embase, Chinese WanFang, and Chinese CNKI databases were used to conduct a literature search. Hazard ratios (HRs) and Pooled odds ratios (ORs) were calculated taking 95% confidence intervals (CIs). The results of the current meta-analysis were further validated using TCGA datasets. RESULTS: A total of 12 eligible studies enrolling 767 patients were included in this meta-analysis. Findings of the analysis showed that CASC15 expression had a significant relation to the metastasis of lymph node (OR = 3.30, 95%CI = 1.88-5.81, p < 0.001), distant metastasis (OR = 2.64, 95%CI = 1.24-5.63, p = 0.012), and high TNM/clinical stage (OR = 2.67, 95%CI = 1.34-5.32, p = 0.005). Additionally, we found that a poor outcome for overall survival (OS) was predicted by an elevation in CASC15 expression (HR = 2.01, 95%CI = 1.71-2.36, p < 0.001). Further investigation of the TCGA dataset revealed that CASC15 had abnormal expression in many cancers, which at least partially validated the findings of the current meta-analysis. CONCLUSIONS: According to the latest meta-analysis and systematic review, high expression levels of CASC15 are associated with poor survival outcomes for solid tumor patients, and the use of CASC15 as a solid tumor prognostic predictor has a solid theoretical foundation.


Assuntos
Neoplasias , RNA Longo não Codificante , Humanos , Prognóstico , RNA Longo não Codificante/genética , Neoplasias/genética , Modelos de Riscos Proporcionais , Razão de Chances , Biomarcadores Tumorais/genética
8.
Cell Death Discov ; 9(1): 297, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582760

RESUMO

Cell fate and proliferation ability can be transformed through reprogramming technology. Reprogramming glioblastoma cells into neuron-like cells holds great promise for glioblastoma treatment, as it induces their terminal differentiation. NeuroD4 (Neuronal Differentiation 4) is a crucial transcription factor in neuronal development and has the potential to convert astrocytes into functional neurons. In this study, we exclusively employed NeuroD4 to reprogram glioblastoma cells into neuron-like cells. In vivo, the reprogrammed glioblastoma cells demonstrated terminal differentiation, inhibited proliferation, and exited the cell cycle. Additionally, NeuroD4 virus-infected xenografts exhibited smaller sizes compared to the GFP group, and tumor-bearing mice in the GFP+NeuroD4 group experienced prolonged survival. Mechanistically, NeuroD4 overexpression significantly reduced the expression of SLC7A11 and Glutathione peroxidase 4 (GPX4). The ferroptosis inhibitor ferrostatin-1 effectively blocked the NeuroD4-mediated process of neuron reprogramming in glioblastoma. To summarize, our study demonstrates that NeuroD4 overexpression can reprogram glioblastoma cells into neuron-like cells through the SLC7A11-GSH-GPX4 signaling pathway, thus offering a potential novel therapeutic approach for glioblastoma.

9.
Biomaterials ; 295: 122026, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36731366

RESUMO

The tumor microenvironment (TME), comprising cancer cells and stroma, plays a significant role in determining clinical outcomes, which makes targeting cancer cells in the TME an important area of research. One way in which cancer cells in the TME can be specifically targeted is by coating drug-encapsulated nanoparticles (NPs) with homotypic cancer cell membranes. However, incomplete targeting is inevitable for biomimetic nanoformulations coated with only cancer cell membranes because of the inherent heterogeneity of the TME. After observing the structural connection between glioma-associated stromal cells (GASCs) and glioma cells from a clinic, we designed a novel drug delivery system that targets the TME by coating polylactic-co-glycolic acid (PLGA) NPs with GASC-glioma cell fusion cell (SG cell) membranes. The resulting SGNPs inherited membrane proteins from both the glioma membrane and GASC membrane, significantly enhancing the tumor targeting efficiency compared to nanoformulations coated with cancer cell membranes alone. We further demonstrated that encapsulation of temozolomide (TMZ) improved the therapeutic efficacy of TMZ in both heterotopic and orthotopic glioma mouse models. Owing to its significant efficacy, our TME-targeting nanoplatform has potential for clinical applications in the treatment of various cancers.


Assuntos
Glioma , Nanopartículas , Camundongos , Animais , Microambiente Tumoral , Glioma/patologia , Sistemas de Liberação de Medicamentos/métodos , Temozolomida/uso terapêutico , Membrana Celular/metabolismo , Nanotecnologia , Nanopartículas/química , Linhagem Celular Tumoral
10.
Front Neurol ; 12: 778062, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35002929

RESUMO

Purpose: An umbrella review was conducted for comprehensively evaluating previous review-based literature together with meta-analysis of observational investigations probing correlations between migraine and medical end-point ramifications in patients. The breadth and validity of these associations were assessed. Methods: Multiple online scientific repositories (including PubMed, Medline, Embase, and Web of Science) were investigated (inception-August 2021) for related meta-analyses focusing on links between migraine and all possible health/medical ramification end-points. A summary effect size and 95% CIs were determined for each identified study with such links. Heterogeneity and small-study influence traces were also evaluated. The AMSTAR 2 platform was employed for evaluating standards of methodology, together with objective criteria, for assessing the standards of datasets from each medical end-point scrutinized in this study. Results: A total of 25 scientific reports comprising 10,237,230 participants for 49 meta-analyses of observational studies were selected. Among such 49 outcomes, 30 demonstrated statistical significance (P < 0.05). Significant associations were observed in multiple diseases, including cardiovascular/cerebrovascular, cerebral, pregnancy-related and metabolic disorders, other outcomes, and mortality. Conclusion: The results showed that migraine increased the risk of 29 health outcomes, though lowered the risk of breast cancer. However, evidence quality was graded as high only for angina. The evidence quality of ischaemic stroke, stroke, MACCE, WMAs, and asthma was graded as moderate. All remaining 24 outcomes had an evidence grade of "weak."

11.
J Chromatogr A ; 1609: 460435, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31515075

RESUMO

Azolla imbricata (Roxb.) Nakai is used as a traditional Chinese medicine. However, very limited information is available on its effective components. Traditional procedures for discovering natural bioactive compounds, especially for minor ones, are usually time-consuming and labor-intensive. Therefore, an efficient approach using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) combined with multicomponent knockout and bioactivity evaluation was developed to obtain more information about the bioactive constituents in A. imbricata. A total of 93 compounds were identified or tentatively identified, including five major components knocked out by semi-preparative HPLC and 88 minor components in the extract with the major components' knockout. These compounds involved chlorogenic acid derivatives, flavonoids, cinnamoyltyrosine derivatives, cinnamic acid derivatives, fatty acids and their derivatives, coumarins, lignans, and chromones. Eighty-two compounds have not been previously reported in the literature for this species, including a new flavanol derivative named brainin D. Among them, 64 compounds, including brainin D, exhibited antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH)-UHPLC-MS as guidance. The new antioxidant, brainin D, was concomitantly isolated and unequivocally identified by spectroscopic methods, and it showed good DPPH radical activity with an IC50 value of 9.3 ±â€¯0.6 µg/mL. In conclusion, the proposed combination approach can be used for systematic identification of minor constituents and guided isolation of new compounds from natural sources with high efficiency. The comprehensive understanding of the minor constituents and antioxidants in A. imbricata lays the foundation for further rational utilization of this medicinal herb.


Assuntos
Antioxidantes/isolamento & purificação , Bioensaio/métodos , Cromatografia Líquida/métodos , Polypodiaceae/química , Espectrometria de Massas em Tandem/métodos , Antioxidantes/análise , Compostos de Bifenilo/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Ácido Clorogênico/análise , Cinamatos/análise , Ácidos Graxos/análise , Flavonoides/análise , Picratos/química , Extratos Vegetais/química , Espectroscopia de Prótons por Ressonância Magnética
12.
J Pharm Biomed Anal ; 163: 197-203, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30317076

RESUMO

Five main components of Azolla imbricata were isolated and identified as caffeoylquinic acid derivatives, four of which were isolated from this species for the first time. The five compounds exhibited strong antioxidant activities and were used as chemical markers for quantitative analysis. A chitosan-based matrix solid-phase dispersion (MSPD) extraction coupled with high-performance liquid chromatography (HPLC) was developed for the determination of the five analytes in A. imbricata. The optimal conditions for the chitosan-based MSPD extraction were as follows: low viscosity chitosan HL-1 as the dispersant, sample-to-dispersant mass ratio of 1:1, 10 mL of a methanol-sulfuric acid aqueous solution (0.2 M) (7:3, v/v) as the elution solvent, and a grinding time of 1 min. Compared with ultrasonic assisted extraction (UAE), the chitosan-based MSPD extraction exhibited higher extraction efficiency, consumed less solvent and time, and provided a cleaner extract. Compared with C18-based MSPD, the developed method was less expensive and more environmentally-friendly. The validated MSPD-HPLC method was efficient, reliable, and applicable to the quantification of caffeoylquinic acids in A. imbricata.


Assuntos
Antioxidantes/análise , Gleiquênias/química , Extratos Vegetais/análise , Ácido Quínico/análogos & derivados , Extração em Fase Sólida/métodos , Antioxidantes/química , Antioxidantes/farmacologia , Radioisótopos de Carbono/química , Quitosana/química , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ácido Quínico/análise , Ácido Quínico/química , Ácido Quínico/farmacologia , Reprodutibilidade dos Testes , Extração em Fase Sólida/instrumentação , Solventes/química , Fatores de Tempo , Ondas Ultrassônicas
13.
Zhonghua Xin Xue Guan Bing Za Zhi ; 35(10): 893-6, 2007 Oct.
Artigo em Zh | MEDLINE | ID: mdl-18206033

RESUMO

OBJECTIVE: The aim of the study was to determine the prevalence and the distribution pattern of lesion site of intracranial vascular stenosis and to identify risk factors for the stenosis in patients with essential hypertension. METHODS: A total of 231 consecutive inpatients with essential hypertension were included in this study. Patients with the history of cerebrovascular diseases and relevant neurological symptoms were excluded. Intracranial vascular stenosis (>50% diameter reduction) was detected using CT angiography (CTA). RESULTS: Of 231 patients, 69 (29.87%) had intracranial artery stenosis. The most common stenosis site is middle cerebral artery (43.69%), followed by carotid siphon (20.39%). The stenosis in internal carotid arterial system (78.64%) was more common than in vertebrobasilar arterial system (21.56%, P < 0.05). The patients with intracranial vascular stenosis were older, had longer history of hypertension, higher levels of systolic blood pressure, higher plasma cholesterol, higher LDL-C. Lp (a), higher urinary microalbumin excretion, thicker ventricular septum, and lower levels of HDL-C than the patients without stenosis. Logistic analysis showed that systolic blood pressure (OR 1.650, 95% CI 1.134 - 2.400, P = 0.023), course of hypertension (OR 1.238, 95% CI 1.072 - 1.429, P = 0.006), LDL-C (OR 2.103, 95% CI 1.157 - 3.823, P = 0.014) and type 2 diabetes (OR 2.325, 95% CI 1.161 - 4.341, P = 0.011) were the independent risk factors of asymptomatic intracranial arterial stenosis. CONCLUSIONS: Nearly 30% inpatients with essential hypertension had asymptomatic intracranial artery stenosis. The most common site of stenosis was middle cerebral artery. Hypertension, dyslipidemia and diabetes were risk factors for the development of intracranial arterial stenosis.


Assuntos
Hipertensão/epidemiologia , Hipertensão/patologia , Doenças Arteriais Intracranianas/epidemiologia , Idoso , Angiografia Cerebral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
14.
Eur J Med Chem ; 89: 581-96, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25462267

RESUMO

By combining the scaffolds of UI-125 and Sorafenib, a series of bis-aryl ureas and amides based on 2-amino-3-purinylpyridine moiety were designed and synthesized as novel DFG-out B-Raf(V600E) inhibitors. Among them, 20c-e, 20g and 21h displayed potent antiproliferative activities against melanoma A375 (B-Raf(V600E)) cell lines with IC50 values of 3.190, 2.276, 1.856, 1.632 µM and 1.839 µM, respectively, comparable with the positive control Vemurafenib (IC50 = 3.32 µM). Selected compounds were tested for the ERK inhibition in human melanoma A375 (B-Raf(V600E)) and SK-MEL-2 (B-Raf(WT)) cell lines by Western blot. The results revealed that our compounds inhibited the proliferation of melanoma A375 cells (B-Raf(V600E)) through ERK pathway, without paradoxical activation of ERK in melanoma SK-MEL-2 cells (B-Raf(WT)). Eventually, 20g and 21h were selected to confirm their inhibitory effects on tumor growth in A375 xenograft models in mice. Compound 20g exhibited equivalent antitumor efficacy in vivo (T/C = 44.37%), compared to Sorafenib (T/C = 37.35%), by 23-day repetitive administration of a single dose of 50 mg/kg without significant body weight loss.


Assuntos
Amidas/farmacologia , Benzamidas/química , Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Purinas/química , Ureia/análogos & derivados , Ureia/farmacologia , Amidas/síntese química , Amidas/química , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas B-raf/metabolismo , Relação Estrutura-Atividade , Ureia/química
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