Distance- and Momentum-Based Symbolic Aggregate Approximation for Highly Imbalanced Classification.

Time-series representation is the most important task in time-series analysis. One of the most widely employed time-series representation method is symbolic aggregate approximation (SAX), which converts the results from piecewise aggregate approximation to a symbol sequence. SAX is a simple and effective method; however, it only focuses on the mean value of each segment in the time-series. Here, we propose a novel time-series representation method-distance- and momentum-based symbolic aggregate approximation (DM-SAX)-that can secure time-series distributions by calculating the perpendicular distance from the time-axis to each data point and consider the time-series trend by adding a momentum factor reflecting the direction of previous data points. Experimental results for 29 highly imbalanced classification problems on the UCR datasets revealed that DM-SAX affords the optimal area under the curve (AUC) among competing time-series representation methods (SAX, extreme-SAX, overlap-SAX, and distance-based SAX). We statistically verified that performance improvements resulted in significant differences in the rankings. In addition, DM-SAX yielded the optimal AUC for real-world wire cutting and crimping process dataset. Meaningful data points such as outliers could be identified in a time-series outlier detection framework via the proposed method.

A Case of Thermal Esophageal Injury Induced by Sodium Picosulfate with Magnesium Citrate.

Although thermal esophageal injuries caused by hot food or tea have been reported, thermal esophageal injury due to sodium picosulfate with magnesium citrate (PSMC) used for bowel preparation is rarely reported. We report the case of a 56-year-old man who presented with esophageal injury after ingestion of PSMC. Instead of dissolving the PSMC in water before ingestion, he drank water immediately after swallowing PSMC powder. As soon as he drank water, he developed severe chest pain and hematemesis. Upper endoscopy revealed severe hemorrhagic, ulcerative mucosal change from upper to mid-esophagus. He was hospitalized for nine days, received conservative treatment (fasting and parenteral nutrition), and recovered without complications. When PSMC is used as a colonic cleansing agent, patients should be educated to take it after dissolving it sufficiently in 150 mL of water to avoid esophageal thermal injury.

Spin-orbit-torque engineering via oxygen manipulation.

Spin transfer torques allow the electrical manipulation of magnetization at room temperature, which is desirable in spintronic devices such as spin transfer torque memories. When combined with spin-orbit coupling, they give rise to spin-orbit torques, which are a more powerful tool for controlling magnetization and can enrich device functionalities. The engineering of spin-orbit torques, based mostly on the spin Hall effect, is being intensely pursued. Here, we report that the oxidation of spin-orbit-torque devices triggers a new mechanism of spin-orbit torque, which is about two times stronger than that based on the spin Hall effect. We thus introduce a way to engineer spin-orbit torques via oxygen manipulation. Combined with electrical gating of the oxygen level, our findings may also pave the way towards reconfigurable logic devices.

Spontaneous coronary artery dissection by intravascular ultrasound in a patient with myocardial infarction.

Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome and sudden cardiac death. The incidence, causes, pathogenesis, and treatment have not been defined clearly, but spontaneous coronary artery dissection should be considered in young patients without major cardiovascular risk factors or in patients in the peripartum period who present with acute coronary syndrome. The treatment is often challenging. Medical treatment is usually considered, and percutaneous coronary intervention or coronary artery bypass surgery may be possible in some patients. We herein report two cases of middle-aged males with myocardial infarction who were treated with percutaneous coronary angioplasty.

Transient J-Wave Appearance in the Inferior-Lateral Leads during Electrical Storm in a Patient with Brugada Syndrome.

A 67-year-old male patient was admitted with an abrupt sudden cardiac death. He represented with an extreme electrical storm of 30 times of ventricular fibrillation (VF) episodes on one day. External shocks were performed to terminate VF. Transient J-wave in the inferior-lateral leads and Brugada electrocardiography pattern on the right precordial leads appeared during the electrical storm. And J-wave disappeared after the termination of electrical storm. We report a case of the appearance of J-wave during electrical storm in a patient with Brugada syndrome.

A case of biopsy-proven chronic kidney disease on progression from acute phosphate nephropathy.

Acute phosphate nephropathy (APhN) following oral sodium phosphate solution (OSP) ingestion as a bowel purgative has been frequently reported. It was recently suggested that APhN could progress to chronic kidney disease (CKD) and a history of APhN might be considered as one of the causes of CKD. However, there are few reports proving APhN as a cause of CKD. Here, we report a case of APhN that progressed to CKD, as proven by renal biopsy.