A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria

The version of record of this article, first published in Gastric Cancer, is available online at Publisher’s website: https://doi.org/10.1007/s10120-024-01511-8.Background: We developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system. Methods: We used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort. Results: LNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76–0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70–0.85) (P = 0.006, DeLong’s test). Conclusions: Our ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria. Mini-abstract: We developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria

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

Molecular dynamics study of ionomer and water adsorption at carbon support materials

Molecular dynamics simulations were applied to unravel the microscopic structure of Nafion ionomer and water adsorbed at graphitized carbon sheets. The considered molecular model resembles microscopic interfaces at which current generation proceeds in catalyst layers of polymer electrolyte fuel cells. The analysis of equilibrated interfacial configurations shows that Nafion ionomer forms a thin adhesive film on the graphite sheet. At low water content, water molecules form clusters around sulfonic acid groups. At high water content, a continuous water film wets the ionomer surface. The structural analysis of this model did not provide any evidence for interconnected water clusters existing inside the ionomer film, which implies that hydronium ion transport will occur mainly along hydrated ionomer surfaces.Des simulations de dynamique mol\ue9culaire ont \ue9t\ue9 appliqu\ue9es pour \ue9lucider la structure microscopique de l\u2019ionom\ue8re Nafion et de l\u2019eau adsorb\ue9s \ue0 la surface de feuillets de graph\ue8ne. Le mod\ue8le mol\ue9culaire \ue0 l'\ue9tude ressemble \ue0 des interfaces microscopiques o\uf9 se d\ue9roule la g\ue9n\ue9ration de courant dans les couches catalytiques des piles \ue0 combustible \ue0 membrane \ue9changeuse de protons. L\u2019analyse des configurations \ue9quilibr\ue9es des interfaces montre que l\u2019ionom\ue8re Nafion forme une couche adh\ue9sive mince sur le graph\ue8ne. \uc0 une teneur en eau faible, les mol\ue9cules d\u2019eau forment des agr\ue9gats autour des groupes d\u2019acide sulfonique. \uc0 une teneur en eau \ue9lev\ue9e, une couche uniforme d\u2019eau mouille la surface de l\u2019ionom\ue8re. L\u2019analyse structurale de ce mod\ue8le n\u2019a pas permis de prouver l\u2019existence d\u2019une interconnexion entre les agr\ue9gats de mol\ue9cules d\u2019eau \ue0 l\u2019int\ue9rieur de la couche d\u2019ionom\ue8re, ce qui laisse entendre que le transport des ions oxonium se produira principalement \ue0 la surface des ionom\ue8res hydrat\ue9s.Peer reviewed: YesNRC publication: Ye

Mechanical Cardiopulmonary Resuscitation and Hospital Survival Among Adult Patients With Nontraumatic Out‐of‐Hospital Cardiac Arrest Attending the Emergency Department: A Prospective, Multicenter, Observational Study in Japan (SOS‐KANTO [Survey of Survivors after Out‐of‐Hospital Cardiac Arrest in Kanto Area] 2012 Study)

Background: Mechanical cardiopulmonary resuscitation (mCPR) for patients with out‐of‐hospital cardiac arrest attending the emergency department has become more widespread in Japan. The objective of this study is to determine the association between the mCPR in the emergency department and clinical outcomes. Methods and Results: In a prospective, multicenter, observational study, adult patients with out‐of‐hospital cardiac arrest with sustained circulatory arrest on hospital arrival were identified. The primary outcome was survival to hospital discharge. The secondary outcomes included a return of spontaneous circulation and successful hospital admission. Multivariate analyses adjusted for potential confounders and within‐institution clustering effects using a generalized estimation equation were used to analyze the association of the mCPR with outcomes. Between January 1, 2012 and March 31, 2013, 6537 patients with out‐of‐hospital cardiac arrest were eligible; this included 5619 patients (86.0%) in the manual CPR group and 918 patients (14.0%) in the mCPR group. Of those patients, 28.1% (1801/6419) showed return of spontaneous circulation in the emergency department, 20.4% (1175/5754) had hospital admission, 2.6% (168/6504) survived to hospital discharge, and 1.2% (75/6419) showed a favorable neurological outcome at 1 month after admission. Multivariate analyses revealed that mCPR was associated with a decreased likelihood of survival to hospital discharge (adjusted odds ratio, 0.40; 95% confidence interval, 0.20–0.78; P=0.005), return of spontaneous circulation (adjusted odds ratio, 0.71; 95% confidence interval, 0.53–0.94; P=0.018), and hospital admission (adjusted odds ratio, 0.57; 95% confidence interval, 0.40–0.80; P=0.001). Conclusions: After accounting for potential confounders, the mCPR in the emergency department was associated with decreased likelihoods of good clinical outcomes after adult nontraumatic out‐of‐hospital cardiac arrest. Further studies are needed to clarify circumstances in which mCPR may benefit these patients