赤外によるCH 3OH-T 2O系の分解過程の研究

The decomposition process in the MeOH-T2O system was studied over a period of 10 months by infrared spectroscopy. The main product was CO with a small amount of CH4 and HCO2 Me. The process was kineticly analyzed, which clarifying that the decomposition of MeOH and CO almost obeys first- and second-order kinetics, respectively. The G value derived for decomposition was -3.5 for MeOH and -11 for CO. These values are different from those received from radiolysis. The reason for this will be discussed

赤外スペクトルによる[Co(en-d 4)_3]Cl_3・3T_2Oのβ放射線分解の研究

β-Radiolysis of [Co(en-d4)3]Cl3・3T2O was studied under a mild condition by means of infrared spectroscopy over a period of 8 months. The spectra became complex due to the appearance of many new bands in the initial process. This is explained in terms of the exchange reaction in hydrogen isotopes between water and ethylenediamine. It was found that ethylenediamine decomposed by ～50% in 100 days, forming ammonia coordinated to a Co2+ ion and an ammonium ion. On the other hand, a Co (Ⅲ) ammine complex, acetylene and so on were not found. A scheme for the β-radiolysis is proposed

赤外分光法による[Co(en)_3]Cl_3・3T_2Oの分解過

The decomposition of [Co(en)3]Cl3・3T2O over a period of 5 months was studied by infrared spectroscopy. The spectrum changed drastically with the disappearance of the bands due to ethylenediamine and the appearance of some new bands. The decomposition process of en → 2NH3+HCCH was analyzed using two models regarding the concentration of T2O. These reveal that about one thousand ethylenediamines decompose due to one β particle in the initial state

Impact of age at diagnosis of head and neck cancer on incidence of metachronous cancer

Abstract Background Metachronous cancer in patients with head and neck cancer (HNC) is common and is associated with a poor prognosis. We aimed to evaluate the incidence of metachronous cancer at different sites according to age at diagnosis of index HNC. Methods We collected data on 2011 patients with oral cancer, oropharynx cancer, hypopharyngeal cancer, and laryngeal cancer as index cancers using the Osaka International Cancer Institute Cancer Registry database between 2005 and 2016. Among these, we analyzed 1953 patients after excluding 5 patients who were not followed-up and 53 patients with simultaneous multiple index cancers. We evaluated the cumulative incidence of metachronous cancer in the esophagus, lung, and other sites according to age at diagnosis of the index HNC using the Kaplan–Meier method. Multivariate logistic regression analysis was performed to identify factors that influenced the incidence of metachronous cancers following HNC. Results The cumulative incidence of metachronous esophageal cancer in young patients (< 65 years) was significantly higher than that in old patients (≥ 65 years) (12.1% vs 8.5% at 5 years, and 16.5% vs 11.2% at 10 years; p = 0.015). On the other hand, the cumulative incidence of the other cancers in young patients was significantly lower than that in old patients (7.8% vs 12.2% at 5 years, and 13.9% vs 15.3% at 10 years; p = 0.017). The cumulative incidence of lung cancer was not significance according to age at diagnosis of the index HNC. In the multivariate analysis, histological type (squamous cell carcinoma) and lesion location (hypopharynx and larynx) were independently associated with metachronous cancers. Moreover, age at diagnosis of the index HNC (< 65 years), histological type (squamous cell carcinoma) and lesion location (hypopharynx) were significant predictors of metachronous esophageal cancer incidence and lesion location (hypopharynx) was a significant predictor of metachronous lung cancer incidence. Conclusion Risk stratification of metachronous cancers with age and other predictors may help to properly manage patients with HNC. Trial registration The present study is a non-intervention trial