ABSTRACT
An efficient copper-mediated ortho-C(sp2)-H thiolation of aromatic amides directed by a novel directing group [4-chloro-2-(1H-pyrazol-1-yl)phenyl]amine has been developed without the need of other additives or oxidants, allowing for an increased usefulness. With the high compatibility of sterically demanding substrates, this reaction is scalable and can tolerate a wide scope of functional groups to provide alkyl and aryl thioethers in good to excellent yields (up to 93%). Furthermore, the protocol has been successfully implemented for the selenylation as well.
ABSTRACT
The mechanical properties of the Al-Mg alloy can be enhanced by adding metallic elements, but a continuous distribution of precipitates at grain boundaries leads to intergranular corrosion during sensitization treatment. In the present work, Mn, Zn additions, water cooling and furnace cooling were executed to investigate their effects on the mechanical and corrosion properties of the Al-4.6Mg alloy. Our results show that adding Mn to Al-4.6Mg alloys may produce grain refinement and dispersion strengthening, increasing tensile strength and hardness. The presence of Mn did not affect the corrosion resistance of Al-Mg alloys. Adding Zn to the Al-4.6Mg alloy increased tensile strength and hardness, but decreased corrosion resistance. Combined, the addition of Mn and Zn to the Al-4.6Mg alloy exhibited the highest tensile strength and hardness, but seriously reduced corrosion resistance. Furnace cooling substituted for water quenching could avoid intergranular corrosion, but slightly decreased the tensile strength and hardness by 7.0% and 6.8%, respectively.
ABSTRACT
BACKGROUND: In this study, we investigated the clinical significance of endobronchial ultrasound elastography for differentiating malignant and benign intrathoracic lymph nodes. METHODS: A meta-analysis was performed to evaluate the sensitivity and specificity of endobronchial ultrasound elastography in diagnosing intrathoracic lymph nodes. Publications before October 1, 2017, were included for analysis. Sensitivity, specificity, and other variables were pooled using the bivariate mixed-effects regression model. RESULTS: Seven studies met the inclusion criteria and were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio was 0.93 (95% confidence interval [CI], 0.85 to 0.97), 0.85 (95% CI, 0.78 to 0.90), 6.3 (95% CI, 4.2 to 9.2), 0.08 (95% CI, 0.04 to 0.18), and 74 (95% CI, 33 to 168), respectively. The summary receiver operating characteristic curve was 0.93 (95% CI, 0.91 to 0.95). CONCLUSIONS: The results revealed endobronchial ultrasound elastography is a new technique with high sensitivity and specificity. It has a fine performance in diagnosing intrathoracic lymph nodes.