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The domestic gas storages are mainly transformed from depleted oil/gas reservoirs. However, the gas storage usually has high demands for well quality, so in principle, the gas storage should not use old wells; even if old wells are used, they must be treated properly first, and then used as gas producer or observation well on condition that their sealing performance and safety must meet the completion requirment of gas storage. Replacing the casing head is a key measure in the utilization of old wells. This paper presents the casing head structure, principles, selection and the method for replacing and installing casing head for old wells. Casing head replacement was performed on two wells and after one injection-production period, the casing was well sealed with no leaking. Through evaluating the expenses occurred, this measure saves about 50 million Yuan compared to single well year-on-year, producing remarkable economic benefits. [ABSTRACT FROM AUTHOR]

Objective: Neutrophil-to-lymphocyte ratio （NLR） and platelet-to-lymphocyte ratio （PLR） play important roles in the poor prognosis of different inflammatory and neoplastic diseases, but their effects on postoperative recurrence of chronic rhinosinusitis（CRS） are unknown. The aim of this study was to investigate the correlation between preoperative NLR and PLR and the risk of postoperative recurrence in CRS. Methods: Clinical data were collected from patients with CRS who underwent initial functional endoscopic sinus surgery from October 2018 to February 2022 at our institution. Follow-up was until February 2023, and the study endpoint was defined as patient postoperative recurrence or follow-up time up to date. The optimal preoperative NLR and PLR threshold values were obtained based on subject work curve analysis, and they were divided into high and low level subgroups, respectively, and the clinical characteristics and postoperative recurrence rates of patients were compared between groups; patients were divided into non-recurrent CRS and recurrent CRS according to their postoperative recurrence, and Kaplan-Meier survival curves and logistic regression analysis were performed to explore the correlation between NLR and PLR and CRS The correlation between NLR and PLR and postoperative recurrence was investigated by Kaplan-Meier survival curve and logistic regression analysis. Results: A total of 630 patients with CRS were included, including 382 and 140 patients with high NLR and high PLR, respectively. The postoperative recurrence rates of CRS patients in the high NLR and high PLR groups were significantly higher than those in the low NLR and low PLR groups（ P <0.05）. The recurrent CRS had higher NLR and PLR levels and higher proportion of high NLR and high PLR than the non-recurrent CRS（ P <0.05）, and similarly the duration of recurrent CRS and the rate of allergic rhinitis with recurrence were significantly higher than the non-recurrent CRS（ P <0.05）. Kaplan-Meier survival curves showed that postoperative CRS was significantly higher in the high NLR and high PLR groups compared with the low NLR and low PLR groups. recurrence was significantly higher（ P <0.05）. In addition, logistic regression analysis showed that high NLR, high PLR, disease duration, and combined allergic rhinitis were significantly associated with an increased risk of postoperative recurrence of CRS（ P <0.05）. Conclusion: Both high preoperative NLR and high PLR are independent risk factors for postoperative recurrence of CRS, and they are expected to be new indicators for postoperative prognostic assessment and risk stratification of CRS patients. In addition, disease duration and comorbid allergic rhinitis were significantly associated with the risk of postoperative recurrence of CRS., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: To transform the antimicrobial peptide fusion gene of cecropin B and rabbit NP-1(CN) into Houttuynia cordata to improve its antimicrobic capability., Method: The fusion gene of CN designed and synthesized artificially was recombined with expression vector pBI121. The recombined vector was transformed to Agrobacterium tumefaciens LBA4404, by which CN gene was transformed to the explants of H. cordata. The transgenic regeneration plantlets were selected by kanamycin and rapid screening PCR. The transgenic plants were identified by PCR-Southern of genomic DNA and RT-PCR. The disease resistances were detected by antibacterial zone trail of leaf extracts to E. coli K12 and infection by Rhizoctonia solani., Result: Gene of interesting CN was inserted into genomic DNA and expressed in transformed H, cordata, whose resistance to E. coli K12 and Rh. solani was stronger than that of the non-transformed control., Conclusion: The fusion gene CN can improve antimicrobic capability of transformed H. cordata.

Objective: To establish and evaluate the vestibular compensation model in rat., Method: The labyrinth of left ear of rat was destructed with the method of operation and chemical labyrinth destruction. After the unilateral vestibular function was lost, spontaneous nystagmus(SN), head deviation( HD) and postural asymmetries (PA) were observed at a series of time points after operation., Result: The degree of PA changed along with the time., Conclusion: Operation and chemical labyrinth destruction may provide a good method to establish the animal model of vestibular compensation.