Double-layer ion acceleration triggered by ion magnetization in expanding radiofrequency plasma sources

Ion energy distribution functions downstream of the source exit in magnetically expanding low-pressure plasmas are experimentally investigated for four source tube diameters ranging from about 5 to 15 cm. The magnetic-field threshold corresponding to a transition from a simple expanding plasma to a double layer-containing plasma is observed to increase with a decrease in the source tube diameter. The results demonstrate that for the four geometries, the double layer and the accelerated ion beam form when the ion Larmour radius in the source becomes smaller than the source tube radius, i.e., when the ions become magnetized in the source tube.This work is partially supported by a Grant-in-Aid for Young Scientists A, Grant No. 22684031, Japan. Part of this work is also supported by TEPCO Research Foundation

Factors Affecting Postoperative Hearing Results in Type IV Tympanoplasty: Preliminary Study of the Influence of External Auditory Canal Packing Material

[Background] Postoperative hearing results of type IV tympanoplasty have been shown to have poorer results than other reconstruction techniques. There are numerous reports evaluating the factors for hearing improvement. This preliminary study aimed to analyze and determine the factors that affect hearing results. [Methods] A total of 80 patients who underwent type IV tympanoplasty were evaluated to participate in this study. The medical records of the candidate patients were collected retrospectively. Fifty out of the 80 recruited patients were excluded due to the following reasons: they could not be followed-up for more than a year after the final operation, their initial surgery was not performed in our department, or they needed a revision surgery. The pre-, intra-, and postoperative factors were evaluated and analyzed using EZR software. Cases were divided into two groups according to postoperative hearing results, and each factor was analyzed univariately. The explanatory variables included in the multivariate analysis were the variables that satisfied P < 0.1 in the univariate analysis. Furthermore, all cases were divided into two groups according to the qualitative variables that showed significant difference in the multivariate analysis, and the background factors were evaluated. [Results] The results of univariate analysis showed P < 0.1 for ‘Age’ and ‘Material of external auditory canal (EAC) packing’. Multivariate analysis showed P < 0.05 for both. The comparison between the two packing material groups showed that the gauze group was more likely to have improved hearing than Spongel? group, and the ossicular chain condition of the gauze group was maintained better. [Conclusion] ‘Age’ and ‘Material of EAC packing’ were considered to be significant factors affecting the postoperative hearing results. The selection and use of packing materials that provide stability should be considered to obtain better postoperative hearing results in type IV tympanoplasty

Successful Surgical Treatment for Dysphagia Secondary to Descending Necrotizing Mediastinitis

Descending necrotizing mediastinitis (DNM) is a life-threatening disease with a high fatality rate that occurs as a complication of deep neck abscess. DNM complicated by severe dysphagia during the postoperative period has been previously reported, but there have been no published cases of surgical treatment for severe dysphagia secondary to DNM. A 63-year-old man was diagnosed with a deep neck abscess followed by DNM. The patient had dysphagia after incision and drainage of the abscess and drainage for DNM with video-assisted thoracic surgery (VATS). A comprehensive long-term physiotherapy program with a speech and language therapist did not reduce his dysphagia. Thus, the patient underwent laryngeal elevation and cricopharyngeal myotomy, which enabled oral intake. Surgery should be considered for prolonged severe restriction of laryngeal elevation and esophageal introitus opening that is unresponsive to physiotherapy with a speech and language therapist

The effect of Hangeshashinto on Oral Mucositis Caused by Induction Chemotherapy in Patients with Head and Neck Cancer

[Background] Oral mucositis (OM) is a side effect of chemotherapy in head and neck cancer. Severe OM often has a large impact on quality of life. Therefore, the treatment of OM during chemotherapy is very important. It was recently reported that Hangeshashinto (TJ-14), a Japanese traditional medicine (Kampo), is effective for OM caused by fluorinated pyrimidinebased agents used in colon cancer. We investigated the efficacy of TJ-14 for OM. [Methods] We enrolled patients with head and neck cancer who were treated with induction chemotherapy between September 2014 and March 2016. In this double-blind trial, patients were randomly assigned to the TJ-14 group or placebo group. Patients were instructed to dissolve 2.5 g of TJ-14 or placebo in 100 ml of drinking water, rinse their mouths with the solution for 30 s and then spit it out. They were not allowed to eat anything for 30 minutes before or after using the mouthwash. [Results] The incidence of ≥ grade 2 OM was 37.5% (three patients) in the TJ-14 group and 50.0% (four patients) in the placebo group, with no significant difference between the two groups. The mean day of onset was 9.7 in the TJ-14 group and 6.7 in the placebo group. The mean duration of ≥ grade 2 OM was 1.3 days in the TJ-14 group and 3.7 days in the placebo group. Thus TJ-14 significantly reduced the duration of ≥ grade 2 OM. [Conclusion] Treatment of OM with TJ-14 was associated with a statistically significant reduction in the duration of ≥ grade 2 OM compared to placebo. Gargling with TJ-14 is a safe and effective method of administering the drug to patients with head and neck cancer