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Objective To provide a theoretical basis for optimizing and improving the culture medium of Yersinia pestis, the effects of different species and different concentrations of animal blood on the growth of Yersinia pestis were investigated. Methods Ten kinds of animal blood including rat blood, rabbit blood and guinea pig blood at four concentrations of 0. 1 %, 0. 5 %, 1 % and 2 % were used as blood stimulators to culture Yersinia pestis in the medium. The culture results were observed and the corresponding statistical analysis was carried out. Results The effect of 10 kinds of animal blood on the number of Yersinia pestis colonies at 1 % concentration was different (P = 0. 015 < 0. 05), and pig blood was better than chicken blood (P = 0. 026 < 0. 05). The effect of four concentrations of pig blood on the number of Yersinia pestis colonies was statistically significant (P = 0. 037 < 0. 05), and it was better than the blank at 1 % concentration (P = 0. 002 < 0. 05). The effects of ten kinds of animal blood at four concentrations on the length of Yersinia pestis were statistically significant (P < 0. 001). The difference in the effect of four concentrations of blood on the length of Yersinia pestis in ten animals was also statistically significant (P < 0. 001). Conclusion When observing the number of colonies, the optimal choice is 1% pig blood. In addition, low concentration and easy - to - obtain blood stimulants can be selected as far as possible. To cultivate a better length of Yersinia pestis, the optimal choice is 0. 1% rabbit blood, which can achieve the desired experimental results and save costs. In addition, using the Herxheimer s sensitive medium with only blood stimulator to culture Yersinia pestis, the characteristics of the strain will not undergo L 一 type transformation, and the overall characteristics of the strain are stable, which is of great significance for the stable passage and preservation of the strain. [ABSTRACT FROM AUTHOR]

目的　总结 1例酒精性肝硬化并发食管胃静脉曲张出血 (EVB) 伴早期食管癌的治疗方法。方法　回顾 性分析1例酒精性肝硬化并发 EVB 伴早期食管癌患者的临床资料，总结其治疗方案。结果　患者中年男性，因“黑 便 2 d，腹痛、呕血5 h”入院，既往有“酒精性肝硬化，食管静脉曲张 (重度) ，门脉高压性胃病”病史 2 年余，“食管中上 段黏膜病变，早癌可能”病史 2 年余，“胃底静脉曲张组织胶注射”手术史4月余，“内镜下食管曲张静脉套扎术”手术 史9 d，饮酒史 30 余年，平均每日饮酒量折合乙醇约 200 g。入院后行急诊内镜检查提示急性上消化道出血，未见明 显活动性出血，给予药物止血、输血、保肝及营养支持等治疗。首次入院3个月后患者返院复查，明确诊断为肝硬化 失代偿期、门静脉高压、EVB、早期食管癌，既往有 EVB 史，符合经颈静脉肝内门体静脉分流术 (TIPSS) 手术适应证， 有内镜黏膜下剥离术 (ESD) 手术指征。排除禁忌证，于首次入院 3个月后行 TIPSS，术后随访 2月余，首次入院 4个 月胃镜检查显示曲张静脉直径较前缩小。排除禁忌证，于首次入院 6 个月行食管静脉曲张内镜下预防性套扎术，套 扎后接着进行早期食管癌 ESD，手术顺利，术后随访 10 个月，病情稳定。结论　对于肝硬化并发EVB伴早期食管癌 的患者，在对黏膜病变处采取内镜治疗等手术操作前可先行 TIPSS，TIPSS 可同时改善食管和胃底静脉的曲张程度， 能减少内镜手术中及术后再出血风险。 [ABSTRACT FROM AUTHOR]

In the modular multilevel converter based multi-terminal DC (MMC-MTDC) system, the virtual synchronous generator (VSG) control cannot take into account the problem of DC voltage fluctuation regulation when maintaining the frequency stability of the AC grid. The U 2 -P DC voltage droop control was introduced into the VSG controller for the receiving-end converter in the MMC-MTDC system, and the VSG control with additional DC voltage was obtained. This control can not only realize the frequency adjustment in the AC region, but also control the DC voltage. By analyzing the influence of moment of inertia in VSG on the frequency response of AC grid, an adaptive virtual moment of inertia adjustment method based on fuzzy control was designed on the basis of additional DC voltage VSG control. By flexibly adjusting the virtual inertia, the converter shows smoother and faster dynamic response performance in the process of supporting frequency fluctuation. The effectiveness of the proposed strategy is verified on the MATLAB/ Simulink simulation platform, which shows that the proposed strategy can adjust the frequency and DC voltage at the same time and can show better frequency dynamic response performance. [ABSTRACT FROM AUTHOR]