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Due to complex structure, large scale, and cold climate, the temperature field and stress field during construction of BoYi Station is different with ordinary mass concrete. Therefore the corresponding crack prevention method must be explored. In order to simulate the complicated construction course, cold climate, multiple materials and unusual structure, a finite element program is adopted. In 5 numerical simulation cases, different temperature control methods are tried to decrease the tensile stress of mass concrete. Based on the simulation analysis and combined with the engineering experience, the scheme and indexes of temperature control and crack prevention are recommended. The mainly measures are controlling pouring temperature, insulation of concrete surface, pipe cooling, block partition and extra steel bar reinforcement. The values of temperature indexes are sharply lower than that of ordinary hydropower station mass concrete. The suggested measures and indexes in this paper, which are various with season, structure position and material, may provide some reference to similar large hydropower station workshop in cold area.

Objective: This systematic review and meta‐analysis aimed to evaluate the risk of malignant sinonasal inverted papilloma (SNIP) according to the type of human papilloma virus (HPV) infection. Methods: The databases of PubMed, EmBase, and Web of Science were searched for studies that reported the risk of malignant SNIP in patients infected by specific types of HPV. The quantitative analyses for pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results: Twenty‐six molecular epidemiological studies that recruited a total of 900 patients with SNIP were selected for the final meta‐analysis. The summary ORs indicated that HPV‐6 (OR: 2.02; 95% CI: 0.47–8.61; P =.343), HPV‐11 (OR: 0.86; 95% CI: 0.26–2.89; P =.806), and HPV‐6/11 (OR: 1.44; 95% CI: 0.59–3.53; P =.426) infections were not associated with the risk of malignant SNIP. However, the risk of malignant SNIP was increased in patients infected with HPV‐16 (OR: 8.51; 95% CI: 3.36–21.59; P <.001), HPV‐11/16 (OR: 7.95; 95% CI: 1.13–56.01; P =.038), HPV‐18 (OR: 23.26; 95% CI: 5.27–102.73; P <.001), and HPV‐16/18 (OR: 24.34; 95% CI: 5.74–103.18; P <.001). Conclusions: This study found that patients infected with HPV types 16, 11/16, 18, and 16/18 were associated with an increased risk of malignant SNIP. However, patients infected with HPV types 6, 11, and 6/11 did not have a significant risk of malignant SNIP. Laryngoscope, 131:1200–1205, 2021 [ABSTRACT FROM AUTHOR]