Ultrasonic assisted tungsten inert gas (U-TIG) welding method was developed. Both U-TIG and conventional TIG welding of AISI 304 stainless steel with 5 mm thickness were experimentally studied in this paper. The results show that the penetration depth is increased up to 300% for weld made with U-TIG welding compared with conventional TIG welding. Ultrasonic energy enhances arc push force, causes a continual high frequency oscillation in the arc plasma and increases welding penetration. These effects are thought to be responsible for enhancing the welding efficiency and improving the appearance of stainless steel weld joints.
BackgroundSmoking is the leading cause of COPD. Exploring molecular markers and understanding the pathogenic mechanisms of smoking-related COPD are helpful for early clinical diagnosis and treatment of the disease. This study aims to identify specific circulating microRNAs (miRNAs) from the blood of COPD patients with a long history of smoking.MethodsBlood samples from four different groups were collected, and miRNA microarray was performed. Differential expression of miRNAs was verified by quantitative polymerase chain reaction. In vitro, THP-1 cells were cultured and stimulated with cigarette smoke extract (CSE) or transfected with miR-149-3p inhibitor/mimics. Protein levels of Toll-like receptor 4 (TLR-4) and nuclear factor κB (NF-κB) were detected using Western blot and immunofluorescence. Interleukin (IL)-1β and tumor necrosis factor (TNF)-α levels were determined by an enzyme-linked immunosorbent assay.ResultsmiRNA profiling revealed that the expression of 56 miRNAs was changed between the four groups. Expression of miR-149-3p in group C (non-smoker non-COPD) was higher than in group S (smoker non-COPD), S-COPD (smoker with stable COPD) and AE-COPD (smoker with acute exacerbation COPD). CSE stimulation down-regulated the expression of miR-149-3p and up-regulated the TLR-4 and NF-κB levels in THP-1 cells. Transfecting miR-149-3p inhibitors in THP-1 cells also increased the expression of its target genes. Furthermore, overexpression of miR-149-3p inhibited the TLR-4/NF-κB signaling pathways and reduced the secretion of IL-1β and TNF-α.ConclusionThis study found that smoking can induce differential expression of circulating miR-NAs, such as down-regulation of miR-149-3p. Reducing miR-149-3p may increase the inflammatory response in COPD patients through the regulation of the TLR-4/NF-κB signaling pathway.
Superhydrophobic surfaces have been intensively investigated for applications requiring self-cleaning and corrosion resistance. The techniques used to fabricate such a coating tend to be costly, time and energy consuming; further surface modification steps are often needed. In this study, a superhydrophobic composite electrodeposit based on a tungsten disulphide nanoparticles dispersed in nickel on a mild steel substrate was successfully developed. At room temperature, the deposit showed a water contact angle of 158.3 deg and sliding angle of 7.7 deg. The effects of operational parameters on surface morphology and superhydrophobicity are discussed. Compared to the substrate, the robust surface of the asprepared coatings exhibited good self-cleaning and corrosion resistance, providing potential for industrial applications.
We demonstrate a high-power red-green-blue laser source based on the quasi-phase-matching and intermittent oscillating dual-wavelength laser technique. A cascaded LiTaO3 superlattice was used to achieve the generation of red light at 660 nm, green light at 532 nm, and blue light at 440 nm to obtain the output of red-green-blue laser light from a diode-side-pumped Q-switched intermittent oscillating dual-wavelength Nd:YAG laser. The average output power of red-green-blue of 1.01 W was achieved under the total fundamental power of 5.1 W, which corresponds to the conversion efficiency of 20%.
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