Objective To compare the gingival retraction effect of Er:YAG laser gingival retraction method and gingival retraction cord. Methods One hundred teeth requiring sub-gingival margin single-crown restoration in Stomatological Hospital of Shanxi Medical University were selected and randomly assigned to Group A and Group B with 50 teeth in each group. Group A and Group B were given gingival retraction cord and Er:YAG laser gingival retraction method. The satisfaction evaluation on gingival retraction effects and the number of patients feeling pain or discomfort during opera-tion were compared between the two groups. Gingival bleeding index (GBI) and periodontal pocket depth (PD) were ap-plied to evaluate the impact of the two methods on periodontal health. Results The two groups had no statistical differ-ence with regard to tooth preparation, impression and model satisfaction (P>0.05). Group B had significantly better gin-gival hemostasis effects than Group A (P<0.05). Group B had fewer patients with pain (12%) than Group A (92%) (P<0.05). There was statistical difference with regard to GBI value and PD value before and after treatment for each method and between two methods(P<0.05). Conclusion Both gingival extraction methods can achieve excellent gingival extraction effects. Er:YAG laser gingival extraction method can reduce gingival bleeding, cause less pain on patients during operation, and have less impact on periodontal health.

Objective:To evaluate the value of B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E mutation detection in the differentiating malignant from benign with Bethesda system for reporting thyroid cytopathology (BSRTC) categories Ⅰ and Ⅲ nodules. Methods:From January 2019 to December 2020, a total of 264 nodules from 263 patients (79 males, 184 females; median age 46 years) were retrospectively enrolled and all patients underwent BRAF V600E mutation detection, fine-needle aspiration cytology (FNAC) and thyroid nodulectomy in the Affiliated Drum Tower Hospital of Nanjing University Medical School. Thirteen nodules of 12 patients had repeat aspirate samples and 51 nodules were examined with multiple genes assay in formalin fixed paraffin embedded tissues. Taken the postoperative histopathological results as the gold standard, the diagnostic efficiency of BRAF V600E mutation was analyzed by comparing the results of multiple genes assay and BRAF V600E mutation detection of repeated puncture samples. Results:Of 264 nodules, 230 were malignant (papillary thyroid cancer (PTC)) and 34 were benign, with BSRTC categories Ⅰ (nondiagnostic) and Ⅲ (follicular lesion) nodules of 58 and 206. The sensitivities of BRAF V600E mutation detection in BSRTC categories Ⅰ and Ⅲ nodules were 77.1%(37/48) and 78.0%(142/182), the specificities were 9/10 and 91.7%(22/24), the positive predictive values were 97.4%(37/38) and 98.6%(142/144), the negative predictive values were 45.0%(9/20) and 35.5%(22/62), and the accuracy rates were 79.3%(46/58) and 79.6%(164/206). The diagnostic concordance of BRAF V600E mutation detection was 90.2%(46/51) in the preoperative and postoperative samples of 51 nodules with preoperative BRAF V600E wild type but postoperative pathology confirmed as PTC and was 11/13 in repeat puncture samples. Conclusion:BRAF V600E mutation detection is an effective diagnostic method for BSRTC categories Ⅰ and Ⅲ nodules.

December 2019 witnessed the outbreak of COVID-19 in Wuhan and spread of the epidemic across the country. As a provincial designated hospital for critical patients, the First Affiliated Hospital of Zhejiang University responded rapidly since then by advocating the four-concentration principles, namely " concentrating patients, experts, resources and treatment" . In its rescue of critical patients, the hospital formulated comprehensive emergency plans, optimized hospital-wide resources, effectively arranged rescue spacing, established medical echelons, and implemented multi-disciplinary strategy. These efforts ensured efficient rescue and treatment, achieving a cure rate up to 98.7% of such patients, with no deaths.