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1.
Appl Radiat Isot ; 210: 111369, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38805983

RESUMEN

In this paper, an epithermal neutron detector suitable for the Prompt Fission Neutron (PFN) uranium logging method is designed by Monte Carlo simulation. According to the simulation results, the epithermal neutron detector composed of a 1 mm cadmium (Cd) layer, a 5 mm high-density polyethylene (HDPE) layer, and a 3He tube is sensitive to epithermal neutrons. Through the simulation test of Monte Carlo in formations with different uranium content, the results show that the uranium content in the formation has an obvious linear relationship with E/T, and the detection limit can meet the minimum standard for uranium ore detection. It meets the design expectation and provides a basis for the optimal design of an epithermal neutron detector.

2.
Rev Sci Instrum ; 95(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38477651

RESUMEN

Ultra-narrow pulses serve as critical components in numerous applications. These pulses have ultra-fast leading edges that typically function as precision trigger signals to synchronize various instruments. Ultra-narrow pulses inherently exhibit an ultra-wide bandwidth, gaining significant attention in diverse electronic systems encompassing communications, radar imaging, electronic warfare, and others. Although several techniques have been explored for generating ultra-narrow pulses, field programmable gate arrays (FPGAs) offer a promising alternative in terms of flexibility and integration. This study introduces a scalable delay pulse synchronizer method with a resolution of 23 ps. A programmable, successive, narrow pulse sequence operating at a 1-GHz repetition frequency is implemented within a monolithic FPGA. The performance of the proposed method is evaluated using an existing board with a general commercial FPGA in the laboratory. This new method presents a convenient and efficient approach of achieving ultra-narrow pulse synchronization, being applicable across various fields.

3.
Front Oncol ; 11: 634026, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33816275

RESUMEN

Nuclear Receptor Binding Protein 2 (NRBP2), one of the pseudokinases discovered during a screen of neural differentiation genes, inhibits tumor progression in medulloblastoma and hepatocellular carcinoma. However, the role and the mechanism of NRBP2 in the regulation of the progression of breast cancer (BC) have not been reported. In our study, NRBP2 was downregulated in human BC tissues compared with the corresponding normal tissues. Moreover, bioinformatics and cellular experiments illustrated that a lower level of NRBP2 contributed to a poor prognosis for patients with BC. In addition, we characterized the NRBP2-overexpressing BC cells and found that NRBP2 overexpression dramatically suppressed cell proliferation and invasion and inhibited the epithelial-mesenchymal transition (EMT) in cells in vitro, whereas knockdown of NRBP2 reversed these effects. Furthermore, overexpression of NRBP2 in the orthotopic breast tumor model significantly reduced lung metastatic nodules in nude mice. Mechanistically, NRBP2 regulated the activation of the 5'-adenosine monophosphate (AMP)-activated protein kinase/ mammalian target of rapamycin (AMPK/mTOR) signaling pathway. Moreover, the inhibition of cell proliferation, invasion and the EMT by NRBP2 overexpression was partially rescued after treatment with an AMPK inhibitor. Conversely, mTOR-specific inhibitors eliminated the effects of NRBP2 knockdown on increasing cell proliferation, invasion and the EMT, which suggested the anti-tumor effect of NRBP2, which may be partially related to the regulation of the AMPK/mTOR pathway. Taken together, NRBP2, a novel and effective prognostic indicator, inhibited the progression of BC and may become a potential therapeutic target for BC.

5.
Am J Med Sci ; 359(2): 123-129, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32039764

RESUMEN

BACKGROUND: The poor outcomes in epithelial ovarian cancer necessitate new treatments. In this work, we systematically analyzed the inhibitory effects of ivermectin and the molecular mechanism of its action in ovarian cancer. METHODS: The effects of ivermectin alone and its combination with cisplatin on growth and survival were examined using cultured ovarian cancer cells and a xenograft mouse model. The molecular mechanism of action of ivermectin, focusing on Akt/mTOR signaling, was elucidated. RESULTS: Ivermectin arrested growth in the G2/M phase and induced caspase-dependent apoptosis in ovarian cancer, regardless of specific cellular and molecular differences. Ivermectin significantly augmented the inhibitory effect of cisplatin on ovarian cancer cells in a dose-dependent manner. Mechanistically, ivermectin suppressed the phosphorylation of key molecules in the Akt/mTOR signaling pathway in ovarian cancer cells. In addition, overexpression of constitutively active Akt restored ivermectin-induced inhibition of Akt/mTOR, growth arrest and apoptosis. In an ovarian cancer xenograft mouse model, ivermectin alone significantly inhibited tumor growth. In combination with cisplatin, tumor growth was completely reversed over the entire duration of drug treatment without any toxicity. Furthermore, the concentrations of ivermectin used in our study are pharmacologically achievable. CONCLUSIONS: Our work suggests that ivermectin may be a useful addition to the treatment armamentarium for ovarian cancer and that targeting Akt/mTOR signaling is a therapeutic strategy to increase chemosensitivity in ovarian cancer.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinoma Epitelial de Ovario/tratamiento farmacológico , Neoplasias Ováricas/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Carcinoma Epitelial de Ovario/genética , Carcinoma Epitelial de Ovario/metabolismo , Carcinoma Epitelial de Ovario/patología , División Celular/efectos de los fármacos , División Celular/genética , Línea Celular Tumoral , Cisplatino/farmacología , Femenino , Fase G2/efectos de los fármacos , Fase G2/genética , Humanos , Ivermectina/farmacología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Proteínas Proto-Oncogénicas c-akt/genética , Transducción de Señal/genética , Serina-Treonina Quinasas TOR/genética , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Ultrasonics ; 101: 106031, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31550624

RESUMEN

Real-time damage evaluation is a critical step to warrant the integrity of turnout systems in railway industry. Nevertheless, existing structural health monitoring (SHM) approaches, despite their proven effectiveness in laboratory demonstration, are restricted from in-situ implementation in engineering practice. Based upon the continued endeavors of the authors in developing SHM approaches and exploring real world applications, an in-situ SHM approach, exploiting active diffuse ultrasonic waves (DUW) and a benchmark-less method, has been developed and implemented in a marshalling station in China. When trains passing a railway turnout, the train-induced loads on the rail track can lead to the growth of defects in the rail, and such growth disturbs the ultrasound traversing at the defect and gives rise to discrepancies between the DUW signals acquired before and after the train's passage. On this basis, a damage index, making use of the defect growth-induced changes in DUW signals, is proposed to identify the presence of defect. The probability of defect growth induced by the train-related load can be used to assess the severity of the defect. Via an online diagnosis system, conformance tests are implemented in Chengdu North Marshalling Station, in which defects in switch rails are identified and the health status of in-service rail tracks are continuously monitored. The results have demonstrated the effectiveness and reliability of DUW-driven SHM towards real world railway turnout applications.

7.
Hum Cell ; 33(1): 131-139, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31612313

RESUMEN

Increasing evidence demonstrates that long noncoding RNAs (lncRNAs) play an important role in the development and progression of human cancers. LncRNA LINC00470 has been reported to function as an oncogene in glioblastoma. Until now, the roles and underlying mechanisms of LINC00470 in the progression of hepatocellular carcinoma (HCC) remain unclear. Here, we found that LINC00470 was upregulated in HCC cells and tissues. High-level LINC00470 was significantly correlated with bigger tumor size, advanced TNM stage and poor prognosis in patients with HCC. Functional studies showed that knockdown of LINC00470 expression inhibited HCC cell proliferation and cell cycle progression, while overexpression of LINC00470 showed the opposite effects. Further investigation suggested that LINC00470 was associated with NF45/NF90 complex and increased its interaction with cyclin E1 mRNA, thus inhibiting the degradation of cyclin E1 mRNA. Additionally, knockdown of cyclin E1 in LINC00470-overexpressed cells abolished its promotive effects on HCC cell proliferation. In summary, our findings suggest that targeting LINC00470 could be a potential therapeutic approach in treating HCC patients.


Asunto(s)
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Proteína del Factor Nuclear 45/genética , Proteínas del Factor Nuclear 90/genética , ARN Largo no Codificante/metabolismo , Proliferación Celular/genética , Humanos
8.
Biochem Biophys Res Commun ; 521(4): 887-893, 2020 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-31711642

RESUMEN

Gastric cancer (GC) is the fourth most frequent malignancy worldwide. Recently, long noncoding RNA (lncRNA) LINC00470 has been demonstrated to play an oncogenic role in human cancer. However, the clinical significance and functional role of LINC00470 in the progression of GC is largely unknown. In this study, our findings showed that LINC00470 was significantly upregulated in GC tissues and cell lines, and correlated with distant metastasis, TNM stage and poor prognosis. Overexpression and knockdown experiments revealed its oncogenic functions on GC cell proliferation, migration and invasion. Mechanistically, LINC00470 associated with PTEN mRNA and suppressed its stability through interaction with the N6-methyladenosine (m6A) writer METTL3. We also showed that LINC00470-METTL3-mediated PTEN mRNA degradation relied on the m6A reader protein YTHDF2-dependent pathway. Taken together, LINC00470 might serve as a therapeutic target for GC patients.


Asunto(s)
Fosfohidrolasa PTEN/genética , ARN Largo no Codificante/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Adenosina/análogos & derivados , Adenosina/genética , Adenosina/metabolismo , Anciano , Línea Celular Tumoral , Movimiento Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Metiltransferasas/genética , Metiltransferasas/metabolismo , Persona de Mediana Edad , Fosfohidrolasa PTEN/metabolismo , Estabilidad del ARN , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo
10.
Appl Radiat Isot ; 150: 39-42, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31121486

RESUMEN

In the present work, a new in-situ prompt gamma-ray neutron activation analysis (PGNAA) setup was developed for the quantitative measurement of chromium (Cr) in aqueous solutions which consists of a 4" × 4″ inch Bismuth Germanate detector and a 300 mCi 241Americium-beryllium neutron source. A series of standard samples were prepared by dissolving Cr compounds in deionized water of analytical pure grade and measured using the in situ PGNAA setup. Quantitative spectrum analysis was conducted using Monte Carlo Library Least-Squares approach (MCLLS). Simulates of elemental library spectra were in silico modeled using the CEARCPG code, which was developed by Prof. Robin Gardner research group in North Carolina State University. The fitted spectra presented were in excellent agreement with the total experimental spectrum, and the correlation coefficients were all nearly 1. After applying the MCLLS approach, the minimum detectable concentration of Cr was 301.5 mg/L, better than that obtained with other setups, and the relative deviation of the Cr quantitative analysis accuracy was less than 4.09%.

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