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The wetting of (100), (110) and (111) MgAl 2 O 4 single crystals by molten Al at 1073–1273 K in vacuum was investigated using a dispensed sessile drop method to determine the effect of the substrate orientation on the wettability and reaction in this system. This system is non-wetting in nature. The initial contact angles are generally in the range of 96–106°, slightly decreasing with increasing temperature but without significant dependence on the MgAl 2 O 4 surface orientation. However, the interfacial reaction is sensitive to the MgAl 2 O 4 surface orientation and temperature. No reaction product was observed at 1073 K while the thickness of the Al 2 O 3 product layer was in the order of (100) > (110) > (111) at 1173 K and 1273 K. During the reactive wetting process, significant reconstruction and "whisker growth" occurred at the periphery of the triple line due to the stress created at the substrate surface as a result of volume change between the reactant and product, and the morphology of the "whiskers" was closely related to the MgAl 2 O 4 crystal orientation. The formation of these "whiskers" not only affected the wetting behavior but also weakened the dependence of the wettability on the MgAl 2 O 4 surface orientation. [ABSTRACT FROM AUTHOR]

The black soil of Northeast China is sticky and agglomerates easily, which often adheres to the surface of a traditional furrow opener during the furrowing process. In this paper, biomimetic design principles in resistance-reducing, anti-adhesion and resistance-reducing mechanism of biomimetic disc furrow opener were studied. Nine kinds of singular convex hull, nine kinds of singular wedge and nine kinds of mixed convex hull and wedge structural biomimetic disc furrow opener were designed, and the furrowing process with the soil simulated by finite element method (FEM).Three types of biomimetic disc furrow opener with less resistance were manufactured by laser processing for comparative test in soil bin based on the simulation results. The test results showed that the resistance of the biomimetic disc furrow opener was less than that of the ordinary disc. The soil-disc stress, influence of biomimetic structures, moisture content and furrow speeds on resistance were discussed. The resistance-reducing rate of D-BC-3 reached the maximum value 15.36% at the furrow speed of 0.6 m/s and the soil moisture content of 20%. It is believed that the biomimetic design principles can provide the significant inspirations for the future design of disc furrow opener with drag reduction.

Objective: To research the role of lymph tracers to protect parathyroid in surgery for papillary thyroid carcinoma., Methods: Patients with papillary thyroid carcinoma who met selected criteria were enrolled in this study. Patients were divided into carbon nanoparticle group, methylene blue group, and conventional surgery group., Results: No significant complication occurred in the patients of carbon nanoparticle and methylene blue groups. In carbon nanoparticle group, methylene blue group and conventional surgery group, the mean numbers of parathyroid glands detected during surgery were 3.1 ± 0.3, 2.9 ± 0.4 and 2.3 ± 0.3 (F = 3.78, P < 0.01) , the rates that parathyroid was cut mistakenly were 1.37% (2/146) , 2.62% (2/97) and 7.14% (6/84) respectively (χ(2) = 17.372, P < 0.05) ; and the incidence of postoperative hypocalcemia were 10.4% (5/48) , 9.1% (3/33) and 17.5% (7/40,χ(2) = 0.671, P = 0.037) ., Conclusion: Thyroid lymphography technique is helpful to protect from the injury to the parathyroid glands in surgery.

Objective: To evaluate the necessity of drainage after thyroidectomy for benign thyroid disorders., Methods: A total of 272 patients who underwent thyroidectomy for benign thyroid disorders were randomly divided into drainage group or non-drainage group. Operating time, postoperative stay time in hospital, comfort of neck assessed by visual analogue scale (VAS) on postoperative day (POD) 0 and POD1 were and the incidence of complications, including post-thyroidectomy bleeding, hematoma, seroma, wound infection, hoarseness, and hypoparathyroidism, were assessed and compared between two groups., Results: Both groups were similar in the mean age, the sex ratio and the underwent procedure types. There was no significant difference in the mean operating time between two groups (87.5 ± 32.0) min and (93.8 ± 30.1) min (t = 0.12, P = 0.45). The mean postoperative hospital stay time of non-drainage group (1.9 ± 0.3) d was significantly shorter than that of drainage group (2.6 ± 0.6) d (t = 1.45, P = 0.02). The mean VAS scores of neck comfort on POD0 and POD1 in non-drainage group were significantly high than those in non-drainage group(t = 2.67, P = 0.03 and t = 0.33, P = 0.006). There were no significant difference in postoperative complications, including permanent hoarseness and hypoparathyroidism, between two groups., Conclusions: No drainage after thyroidectomy for benign thyroid disorders does not increase postoperative complications, with the increase in postoperative neck comfort, the decrease in hospital stay time and potential wound infections. The routine drainage is not necessary after thyroid surgery for benign disorders.