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Nasopharyngeal carcinoma (NC) poses a threat to the life of patients. Long non- coding RNA (LncRNA) is a novel kind of non-coding RNA, which plays a pivotal role through sponge microRNA (miRNA). Abnormal expression of small nucleolar RNA host gene 8 (SNHG8) is involved in various tumors; however, the role of SNHG8 in NC remains unknown. Quantitative real-time PCR (qRT-PCR) and Western blotting was employed to detect the expression levels of SNHG8, miR-588, and high mobility group A2 (HMGA2). Cell proliferation, migration, and invasion were analyzed by CCK-8 and transwell assays. miR-588 binding sites in SNHG8 were predicted by LncBase analysis. Luciferase reporter and RNA pull-down assay were used to confirm the interaction of SNHG8 and miR-588. SNHG8 was highly expressed in NC cells. The prognosis of the patients with NC in the high expression levels of SNHG8 was poorer than that in the low expression levels. The expression of SNHG8 was closely related to tumor size, TNM stage, and distal metastasis. Knockdown of SNHG8 inhibited cell proliferation, migration, and invasion of NC. SNHG8 targeted miR-588. Inhibition of miR-588 could partially reverse the knockdown of SNHG8 in NC cells, and miR-588 targeted HMGA2. In conclusion, SNHG8 promotes proliferation, migration, and invasion of NC cells through miR- 588/HMGA2 in NC as an oncogene. Key words: SNHG8, cell proliferation, cell migration and invasion, nasopharyngeal carcinoma, miR-588, HMGA2, oncogene. Le carcinome nasopharynge (CN) constitue une menace pour le pronostic vital des patients. L'ARN long non codant (LncRNA) est une nouvelle sorte d'ARN non codant, qui joue un role pivot par l'intermediaire du miARN eponge. L'expression anormale de SNHG8 joue un role dans diverses tumeurs. Cependant, le role de SNHG8 dans le CN demeure inconnu. A l'aide des techniques de PCR quantitatif par transcriptase inverse et d'immunobuvardage de Western, nous avons decele les taux d'expression de SNHG8, du miR-588 et de HMGA2. Nous avons etudie la proliferation, la migration et l'invasion des cellules a l'aide des epreuves CCK-8 et de transwell. Il etait possible de predire les sites de liaison du miR-588 avec SNHG8 a l'aide de l'analyse de la LncBase. A l'aide des epreuves de rapporteur par la luciferase et d'immunoprecipitation (<< pull-down >>) de l'ARN, nous avons confirme l'interaction entre SNHG8 et le miR-588. Les resultats ont montre que SNHG8 etait fortement exprime dans les cellules de CN. Le pronostic des patients atteints de CN presentant des taux d'expression de SNHG8 eleves etait moins favorable qu'avec de faibles taux d'expression. L'expression de SNHG8 etait etroitement liee a la taille de la tumeur, au stade TNM et a la presence de metastases a distance. La repression (<< knockdown >>) de SNHG8 permettait d'inhiber la proliferation, la migration et l'invasion des cellules de CN. SNHG8 ciblait le miR-588. L'inhibition du miR-588 pouvait inverser partiellement la repression de SNHG8 dans les cellules de CN. Le MiR-588 ciblait HMGA2. En conclusion, SNHG8 favorise la proliferation, la migration et l'invasion des cellules du CN par l'intermediaire du complexe miR-588/HMGA2 en tant qu'oncogene dans le CN. [Traduit par la Redaction] Mots-cles: SNHG8, proliferation, migration et invasion cellulaires, carcinome nasopharynge, miR-588, HMGA2, oncogene., Introduction Nasopharyngeal carcinoma (NC) is a malignant tumor that occurs at the top and side walls of the nasopharyngeal cavity. It is one of the malignant tumors with high incidence, [...]

Silicon nitride (Si 3 N 4) has excellent thermostability, low density, corrosion resistance, high mechanical strength. Therefore, it is widely used in the aerospace and military field. Femtosecond laser ablation is a potential method to fabricate micro features on silicon nitride surfaces, however thermal accumulation effect is a non-negligible challenge. In this paper, a comprehensive investigation of laser ablation of silicon nitride under different auxiliary processing environments were conducted in ambient air, water-confined environment and low temperature, accompanied with analysis of ablation depth, surface roughness, SEM topography and EDS detection. The experimental results showed that the laser ablation performed in ambient air would form obvious ablation depth, the depth would increase with number of ablation layers increased, but its surface roughness would be lager due to the thermal accumulation effect. The laser machining in low temperature could suppress the plasma shielding effect, enlarge ablation depth and reduce the degree of thermal damage. Besides that, it could also reduce the oxidation and surface roughness. The water-confined laser ablation could restrain the oxidation effectively, but it caused bubbles attaching on the machined surface, distortion of machined region, decreasing of material removal rate and other negative phenomena either. Moreover, the surface roughness increased and laser ablation depth decreased with the scanning speed increasing. Hence, femtosecond laser ablation under low temperature could improve the surface quality and reduce the thermal accumulation effect significantly. [ABSTRACT FROM AUTHOR]