RESUMO
Coal spontaneous combustion risk assessment is a global technical challenge for the sustainable development of deep mining technology, and C2H4 is a key indicator for early warning of coal spontaneous combustion. Tunable diode laser absorption spectroscopy (TDLAS) has the advantages of high selectivity, high sensitivity, high accuracy and real-time on-line measurement, and it can detect multiple gases simultaneously, so it has significant advantages in the accurate detection of coal spontaneous combustion indicator gases. To address the problem of cross-interference between the near-infrared absorption lines of CH4 and C2H4, which are the indicator gases of spontaneous combustion in coal, a multi-line fitting method was proposed in this study to calibrate the concentration of C2H4. The high-precision Environics2000 automatic standard gas dispenser from the United States, which has a built-in CPU computer control and data control and processing system, was used. Its gas concentration accuracy: ± 1.0%, gas flow accuracy: ± 1.0%, gas repeatability accuracy: ± 1.0%, flow linearity accuracy: ± 0.5%, and inlet operating pressure: minimum 10 psig (0.67 bar) ~ 75 psig (5.04 bar). The measured and simulated WMS-2f/1f signals were multilinearly fitted using a multilinear fitting algorithm and wavelength modulation spectroscopy (WMS), and the measurement of C2H4 concentration was achieved based on the extracted spectral line information. The results show that the maximum relative error of C2H4 concentration measurement is 2.40%, which is 54% lower than that of the conventional 2f peak measurement method, thus demonstrating the effectiveness of the multilinear fitting algorithm in the inversion of C2H4 concentration under the interference of absorption lines. In addition, this study has far-reaching implications for the application of TDLAS technology in the accurate detection of coal spontaneous combustion indicator gases.
RESUMO
OBJECTIVE: MicroRNAs (miRNAs) are endogenous, non-coding small RNAs, which play an important part in regulating organismal and pathological processes. Previous studies have shown that miRNA-199 acts as a tumor suppressor gene. However, we aimed to explore the characteristics and function of miRNA-199 in lung cancer (LCa), so as to further study its relationship with clinicopathological parameters and prognosis. PATIENTS AND METHODS: Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect miRNA-199 expression in 75 pairs of LCa tissues and normal adjacent tissues. In addition, the relationship between miRNA-199 expression and pathological features along with the prognosis of LCa patients were investigated. Besides, the expression level of miRNA-199 in LCa cells was further validated by qRT-PCR. In addition, miRNA-199 overexpression expression model was constructed in LCa cell lines H1299 and SPCA1. Cell counting kit-8 (CCK-8), cell cloning experiments, transwell invasion and migration assays were performed to analyze the effect of miRNA-199 on the biological function of LCa cells. Finally, the potential mechanism was explored using Western blot. RESULTS: qRT-PCR results displayed that the expression level of miRNA-199 in LCa tissues was significantly lower than that of the normal tissues. Compared with patients with high miRNA-199 expression, patients with lowly-expressed miRNA-199 had higher rates of lymph node metastases and distant metastases, and their overall survival rates were lower. In addition, the proliferation, invasion and metastasis of the miRNA-199 overexpression group were significantly increased than that in the negative control group. Western Blot results showed that the expression of key proteins in the EMT pathway, such as N-cadherin, Vimentin, ß-catenin and MMP9 significantly increased in miRNA-199 overexpression group. Moreover, we also found that miRNA-199 and RGS17 have mutual regulation, which inhibited the malignant progression of LCa. CONCLUSIONS: miRNA-199 expression was down-regulated in LCa and was significantly associated with LCa stage, distant metastasis, and poor prognosis. Besides, miRNA-199 may inhibit the malignant progression of LCa by interacting with RGS17.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Metástase Linfática/genética , MicroRNAs/metabolismo , Proteínas RGS/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Estimativa de Kaplan-Meier , Pulmão/patologia , Pulmão/cirurgia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Estadiamento de Neoplasias , Pneumonectomia , Prognóstico , RNA Interferente Pequeno/metabolismo , Taxa de SobrevidaRESUMO
OBJECTIVE: This paper was to construct three-dimensional finite element model of rat molar, and to access mechanical stress distribution in the tooth and periodontia. METHODS: The first maxillary molar of adult rat was moved for 2 weeks with initial force of 40 g and 100 g. The histological specimen of tooth and surrounding structures were sectioned serially at 4 microns-thick slices in the coronary direction. The section's microscopic photographic images were made every 140 microns. The structural information of images was traced and fed into computer for three-dimensional reconstruction of the structure and finite element model. RESULTS: The stress distribution in periodontia which lies between tooth and alveolar bone was very complicated. CONCLUSION: The three-dimensional finite element model of rat molar is simple, precise, and effective for analyzing stress in tooth and periodontia.
