RESUMEN
To improve the surface roughness of SKD61 die steel and reduce the secondary overflow of the molten pool, a steady magnetic field-assisted laser polishing method is proposed to study the effect of steady magnetic field on the surface morphology and melt pool flow behavior of SKD61 die steel. Firstly, a low-energy pulsed laser is used for the removal of impurities from the material surface; then, the CW laser, assisted by steady magnetic field, is used to polish the rough surface of SKD61 die steel to reduce the material surface roughness. The results show that the steady magnetic field-assisted laser polishing can reduce the surface roughness of SKD61 die steel from 6.1 µm to 0.607 µm, which is a 90.05% reduction compared with the initial surface roughness. Furthermore, a multi-physical-field numerical transient model involving heat transfer, laminar flow and electromagnetic field is established to simulate the flow state of the molten pool on the surface of the SKD61 die steel. This revealed that the steady magnetic field is able to inhibit the secondary overflow of the molten pool to improve the surface roughness of SKD61 slightly by reducing the velocity of the molten pool. Compared with the molten pool depth obtained experimentally, the molten pool depth simulation was 65 µm, representing an error 15.0%, thus effectively demonstrating the accuracy of the simulation model.
RESUMEN
In order to explore the clamping fatigue properties of shrink-fit holders, ANSYS software was used in this study to analyze the thermal and contact stresses during the clamping process of the shrink-fit holder, and the fatigue analysis was performed by selecting the dangerous areas based on the two stresses. A numerical control shrink-fit holder clamping fatigue test device was manufactured, and the automatic clamping of the shrink-fit holder was executed in this study. After 500 clamping repetitions, a milling test was carried out on the shrink-fit bracket. By collecting the vibration signal of the workpiece during processing and measuring the change in the surface roughness of the workpiece, and then analyzing the change in the machining performance of the shrink-fit holder under different clamping times, we were able to compare and verify the accuracy of the finite element fatigue analysis.
RESUMEN
It was shown in this study that knockdown of ClC-3 expression by ClC-3 siRNA prevented the activation of hypotonicity-induced chloride currents, and arrested cells at the G0/G1 phase in nasopharyngeal carcinoma CNE-2Z cells. Reconstitution of ClC-3 expression with ClC-3 expression plasmids could rescue the cells from the cell cycle arrest caused by ClC-3 siRNA treatments. Transfection of cells with ClC-3 siRNA decreased the expression of cyclin D1, cyclin dependent kinase 4 and 6, and increased the expression of cyclin dependent kinase inhibitors (CDKIs), p21 and p27. Pretreatments of cells with p21 and p27 siRNAs depleted the inhibitory effects of ClC-3 siRNA on the expression of CDK4 and CDK6, but not on that of cyclin D1, indicating the requirement of p21 and p27 for the inhibitory effects of ClC-3 siRNA on CDK4 and CDK6 expression. ClC-3 siRNA inhibited cells to progress from the G1 phase to the S phase, but pretreatments of cells with p21 and p27 siRNAs abolished the inhibitory effects of ClC-3 siRNA on the cell cycle progress. Our data suggest that ClC-3 may regulate cell cycle transition between G0/G1 and S phases by up-regulation of the expression of CDK4 and CDK6 through suppression of p21 and p27 expression.
Asunto(s)
Carcinoma/genética , Canales de Cloruro/genética , Ciclina D1/genética , Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 6 Dependiente de la Ciclina/genética , Neoplasias Nasofaríngeas/genética , Carcinoma/patología , Ciclo Celular/genética , Línea Celular Tumoral , Canales de Cloruro/antagonistas & inhibidores , Ciclina D1/antagonistas & inhibidores , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patología , ARN Interferente Pequeño/genética , Fase S/genética , Activación Transcripcional/genéticaRESUMEN
The aim of this study was to investigate the relationship between the acetylcholine concentration in the blood and gelsenicine-induced death in mice. Kunming mice were given intraperitoneal injections of normal saline, gelsenicine or different doses of acetylcholine chloride. Atropine was given to the mice which received gelsenicine or medium dose acetylcholine chloride injection. The blood was sampled immediately when the mice died or survived for 20 min after injection. The acetylcholine concentration and acetylcholinesterase activity in the blood were measured by the testing kits, and the mortality was calculated and analyzed. The results showed that half lethal dose of gelsenicine (0.15 mg/kg) reduced the acetylcholinesterase activity and increased the blood acetylcholine concentration. The blood acetylcholine concentration of the dead mice in the gelsenicine group was increased to 43.0 µg/mL (from 31.1 µg/mL in the control), which was lower than that (53.9 µg/mL) of the dead mice in the medium dose acetylcholine chloride group, but almost equal to that (42.7 µg/mL) of the survival mice in the medium dose acetylcholine chloride group. Atropine could successfully rescue the mice from acetylcholine poisoning, but its efficiency of rescuing the mice from gelsenicine intoxication was weak. These results suggest that gelsenicine can inhibit acetylcholinesterase activity and increase blood acetylcholine concentration, but the accumulation of acetylcholine may not be the only or main cause of the death induced by gelsenicine in mice.
Asunto(s)
Muerte , Acetilcolina , Animales , Alcaloides Indólicos , RatonesRESUMEN
STUDY QUESTION: Is chloride channel-3 (ClC-3) involved in regulating the biological behavior of endometrial stromal cells (ESCs)? SUMMARY ANSWER: ClC-3 promotes endometriotic cell migration and invasion. WHAT IS KNOWN ALREADY: ClC-3 plays a significant role in the migration and invasion of various kinds of cells. STUDY DESIGN, SIZE, DURATION: An ITALIC! in vitro investigation of the effect of ClC-3 on the migration and invasion of ectopic ESCs from patients with endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The ectopic and eutopic endometrial samples from 43 female patients with endometriosis and the endometrial samples from 39 non-endometriotic female patients were collected. Primary cells from these samples were isolated and cultured. Real-time RT-PCR, immunohistochemistry and western blot were used to detect the expression of ClC-3 and matrix metalloproteinase 9 (MMP-9). Small interfering RNA (siRNA) technology was employed to knock down ClC-3 expression. The migration and invasion ability of ESCs was measured by the transwell assay with uncoated or Matrigel-coated membranes. MAIN RESULTS AND THE ROLE OF CHANCE: The expression of ClC-3 mRNA and proteins was significantly up-regulated in the ectopic tissues from endometriotic patients, while that in the eutopic endometrial tissues of the same patients did not significantly differ from that in non-endometriotic patients. The migration and invasion ability and MMP-9 expression was increased in the ESCs from ectopic endometrial tissues. The knockdown of ClC-3 expression by ClC-3 siRNA inhibited ESC migration and invasion and attenuated the expression of MMP-9. ClC-3 expression level was well-correlated to the clinical characteristics and symptoms of endometriosis patients, including infertility, dysmenorrhea, chronic pelvic pain, dyspareunia and diameter of endometriosis lesion. LIMITATIONS, REASONS FOR CAUTION: Further studies are needed to examine the regulatory mechanism of estrogen on ClC-3 expression of ESCs. WIDER IMPLICATIONS OF THE FINDINGS: ClC-3 is involved in the migration and invasion processes of ESCs and can regulate MMP-9 expression. Up-regulation of ClC-3 expression may contribute to endometriosis development by regulating MMP-9 expression. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Natural Science Foundation of China (81173064, 81272223, 81273539), the Ministry of Education of China (20124401110009), the Natural Science Foundation of Guangdong Province (S2011010001589) and the Science and Technology Programs of Guangdong (2013B051000059), Guangzhou (2013J500015) and Dongguan (2011108102006). The authors have no conflict of interest.