East Japan Railway (Japan)

It is becoming increasingly important to investigate not only micro-/macrovascular complications, but also comorbidities associated with diabetes. In the Asahi Diabetes Complications Study (Asahi Study), in addition to micro-/macrovascular complications, the onset and progression of dementia and sarcopenia were also investigated in patients with diabetes. The Asahi Study is a prospective 8-year observational cohort study of subjects with diabetes receiving outpatient care at the Institute of Medical Science, Asahi Life Foundation. Participants were enrolled between November 2014 and December 2017. The baseline data include the age, HbA1c level, and median duration of diabetes. In addition, medication use, prevalence of micro-/macrovascular complications, and presence/absence of malignant neoplasms were also assessed. A total of 49 patients with type 1 DM (T1DM group) and 791 patients with type 2 DM (T2DM group) were enrolled in the study. The mean age was 58.4 years in the T1DM group and 64.9 years in the T2DM group. Other baseline characteristics (T1DM/T2DM) were: mean HbA1c 7.5%/7.0%; median duration of diabetes 23 years/18 years. In regard to medication history, in the T2DM group, 57.3% were receiving oral hypoglycemic agents, 5.6% were receiving injectable GLP-1 receptor agonists, and 28.4% were receiving insulin therapy. The prevalences of microvascular complications, macrovascular complications, and malignant neoplasms were approximately 30-50%, 10%, and 7%, respectively, in the study participants. This 8-year observation study may offer valuable insights into the relationship between risk factor management and development of diabetic complications/comorbidities in persons with diabetes.

Unpleasant odors in restrooms in railway stations and on trains are one of the objects of many complaints from railway customers. Therefore, countermeasures to reduce these unpleasant odors are required. In railway station restrooms, we are investigating the sources of ammonia, one of the main compounds responsible for unpleasant odors in public restrooms. To conduct this investigation, we developed a prototype of a portable, highly sensitive ammonia measuring instrument. We used this instrument to search for sources of ammonia in men's railway station restrooms and confirmed the difference in concentration of ammonia depending on cleaning methods and seasons. In addition, we verified the effectiveness of countermeasures implemented by cleaning companies to reduce unpleasant odors.

Although recent research aims to extend the lifespan and reduce the maintenance requirements of railway electrical equipment, it remains difficult to quantitatively predict and evaluate equipment deterioration caused by corrosion and wear. In this study, we analyzed and evaluated the deterioration trends of messenger wires and hinged cantilevers in Shinkansen power facilities, where corrosion is the main deterioration factor. Messenger wires and hinged cantilevers are important components around the contact wire. A common issue with both is that, although the deterioration state of the equipment should be managed as a key indicator, the deterioration state in tunnels has not been evaluated. Therefore, in this study, the corrosion tendency of galvanized steel, which is the main material for both, was evaluated. No significant galvanization corrosion was observed, except in equipment directly exposed to water leakage. This indicates that if direct water leakage can be controlled, galvanized steel can be used continuously for more than 40 years.

Tsunami evacuation planning is a critical and urgent social issue that requires consideration of traffic impediments and road blockages caused by earthquakes and flooding. Traditional pedestrian evacuation models have focused primarily on micro-scale environments spanning a few dozen meters within buildings, limiting their applicability to tsunami scenarios involving travel over hundreds of meters. This study aims to (1) extend a cell FD-based dynamic traffic distribution model into a zonal MFD-based model and (2) apply it to pedestrian traffic to construct an optimization model that outputs efficient evacuation directions. Focusing on real local cities in Japan, we compare optimal solutions for different pedestrian evacuation direction scenarios. The results confirm that if pedestrians can preemptively understand multiple safe evacuation routes, rather than relying solely on the nearest facilities, efficient directional guidance that reduces congestion can be achieved.

Abstract Background: The association between decreased zinc and poor glycemic control has been revealed in diabetic patients. However, the involvement of zinc in glucose metabolism in healthy, non-diabetic individuals remains unclear. Methods: Company T employees and their spouses who underwent the milestone-age health checkups at the Tokyo Health Service Association were recruited in the study (n=533). The following variables were obtained from blood and urine samples and questionnaires: three zinc measures (serum zinc, urinary zinc, and zinc intake); two obesity-related measures (visceral fat and adiponectin); three insulin-related measures (insulin, HOMA-β, and HOMA-IR); and two glucose-related measures (fasting plasma glucose and HbA1c). Results: Correlation analysis between zinc measures revealed a significant correlation between serum zinc and urinary zinc, but not between the other pairs. Correlation analysis between zinc measures and obesity-, insulin-, and glucose-related measures revealed weak but significant correlations between serum zinc and adiponectin and HbA1c, as well as between urinary zinc and fasting plasma glucose and HbA1c. A path analysis using structural equation modeling confirmed that serum zinc was directly linked to urinary zinc and adiponectin, which affected blood glucose levels (HbA1c) directly and indirectly by influencing insulin secretion function (HOMA-β). Conclusion: This is the first study to statistically demonstrate the pathway linking zinc to blood glucose levels in healthy, non-diabetic adults using objective measurement data. Lower serum zinc levels were associated with lower adiponectin levels and lower insulin secretory function, resulting in higher blood glucose levels.

AimThis study aims to evaluate the associations between the copper/zinc (Cu/Zn) ratio and inflammatory biomarkers and the incidence of chronic kidney disease (CKD) in individuals with type 2 diabetes and to validate our previous cross-sectional study using the baseline data of this study.MethodsWe conducted a prospective, observational study of 416 individuals with type 2 diabetes without CKD. We used multivariable Cox proportional hazard models to determine the HRs for CKD incidence. The Cu/Zn ratio and soluble tumor necrosis factor-α receptor 1 (sTNFαR1) concentrations (pg/mL) were analyzed as continuous variables and as categories classified according to each cutoff value for detecting CKD. The high-sensitivity C-reactive protein (hsCRP) concentrations between these categories were compared.ResultsCKD was identified in 165 participants. The Cu/Zn ratio and sTNFαR1 concentrations were identified as significant predictors, independent of each other, after full adjustment (P = 0.048 and P = 0.006, respectively). Compared to the Cu/Zn <1.281 and sTNFαR1 <1081 group, the HRs for the CKD incidence were significantly higher in the Cu/Zn <1.281 and sTNFαR1 ≥1081 group (HR 2.06, 95% CI 1.34-3.26) and even higher in the Cu/Zn ≥1.281 and sTNFαR1 ≥1081 group (3.29, 1.97-5.50) after full adjustment. The hsCRP concentrations were significantly highest in the Cu/Zn ≥1.281 and sTNFαR1 ≥1081 group compared with the other three groups (all P < 0.05) and were significantly higher in the Cu/Zn ≥1.281 and sTNFαR1 <1081 group and in the Cu/Zn <1.281 and sTNFαR1 ≥1081 group compared with those in the Cu/Zn <1.281 and sTNFαR1 <1081 group (both P < 0.05).ConclusionsThe Cu/Zn ratio and sTNFαR1 concentrations are independent predictors of the incidence of CKD in individuals with type 2 diabetes. Furthermore, under elevated sTNFαR1 concentrations, an increase in the Cu/Zn ratio may further aggravate inflammation and accelerate the incidence of CKD in individuals with type 2 diabetes. These new findings are supported by the results from our previous cross-sectional study.

In DC-electrified railway, when the substation output voltage is high, the train voltage increases, and light-load regenerative brake control is activated, resulting in a decrease in the regenerative energy. When the substation output voltage is low, the main circuit loss and power loss increase owing to the increase in the acceleration time and current. Therefore, the substation output voltage that maximizes the energy-saving effect is determined by the trade-off relationship between regenerative energy and consumed energy. The purpose of this study is to focus on the correlation between the regenerative vehicle FC voltage and regenerative energy reduction and its position dependence, and to propose a method for determining the output voltage of multiple substations that can maximize the regenerative power beyond substations. The proposed method reduces the number of voltage parameters, which contributes to a considerable reduction in the number of simulations.

A fishway is a structure that aids fish migration by preventing the blockage of migration paths by dams. However, excessive water through a dam’s gate prevents fish from reaching the fishway. We hypothesized that fishways are sensitive to dams, especially those with independent gates to release water downstream in different spatial patterns. To test this, the sensitivity of fishways to the coordinated operation of multiple gates was investigated via controlled systematic gate manipulation. By manipulating dam gates, we aimed to obtain hydraulic phenomena that circumvent the obstacles to fishways. Numerical model simulations and actual dam discharge experiments showed that releasing water from a gate near fishways facilitated continuity between the downstream regions and fishways, eliminating circulating eddy flows at the fishway entrance. For biovalidation, Oncorhynchus keta was radio-tagged and released ∼1 km downstream of the dam after applying the existing (circulation flow) and new operation methods (no circulation flow). The arrival rate to the fishway was only 40% in the presence and 100% in the absence of circulating flow; this corroborates our hypothesis by showing that changing the dam’s flow release pattern to eliminate circulating flow ensured hydraulic continuity between the mainstream river region and fishways, benefiting fish passage.

本研究の目的は、東京都港区のTAKANAWA GATEWAY CITYにおけるデジタルツインによる「防災エリアマネジメントDX」によって得られた知見を共有することである。膨大なCAD/BIMデータから3次元都市空間情報を開発し、国土交通省が開発した都市空間情報基盤であるPLATEAUと統合し、屋内外の避難シミュレーション環境と3Dモデルを組み合わせた。また、一連のシステムが都市再生安全保証計画の改定に資することを確認した。加えて、本研究の実績は、エリアマネジメントのインフラとしても考えることができる。