Ken-Ichi Tanaka

Background/Objectives: Postoperative analgesia is important for reducing biologically invasive reactions to surgery. In Japan, postoperative analgesia, including indices of analgesia, has not been adequately addressed. This study aimed to determine the relationship between postoperative pain and postoperative course and the importance of analgesia for early recovery. Methods: Patients who underwent any of seven surgical procedures in gastrointestinal, thoracic, and cardiac surgery were enrolled. The primary endpoint was a median Prince Henry Pain Scale score from postoperative days 1 to 3. Secondary endpoints were the quality of recovery on postoperative day 7 (Quality of Recovery-15 [QoR-15]) and the length of postoperative hospital stay. Results: Median postoperative pain levels among surgeries were 3 on day 1, 2 on days 2 and 3, 1 on day 7, and 1 at discharge. In both univariate and multivariate analyses, the use of postoperative epidural analgesia and intravenous patient-controlled analgesia (IV-PCA) were significant predictors of early postoperative pain. Only early postoperative pain was a significant predictor of QoR-15 score. Regular use of acetaminophen, early postoperative pain, no appetite, and postoperative complications were significant in affecting the length of postoperative hospital stay. In the comparison of early postoperative pain according to whether epidural analgesia and IV-PCA were used, the group that used both methods had the least pain. Conclusions: In Japan, early postoperative pain persists after major surgical procedures and affects postoperative quality of recovery and length of hospital stay. The use of epidural analgesia, IV-PCA, or both appeared to be effective in overcoming early postoperative pain, thereby enhancing early postoperative recovery.

The seasonal incidence of acute abdomens, such as appendicitis, is reportedly more common in summer but is reported less frequently in Asia. Additionally, seasonal variations in the severity of acute abdomens have been evaluated insufficiently. This study evaluated the seasonal variations in the incidence and severity of acute abdomens in Japan. This retrospective observational study used a multicenter database containing data from 42 acute hospitals in Japan. We included all patients diagnosed with acute appendicitis, diverticulitis, cholecystitis, and cholangitis between January 2011 and December 2019. Baseline patient data included admission date, sequential organ failure assessment score, presence of sepsis, and disseminated intravascular coagulation. We enrolled 24,708 patients with acute abdomen. Seasonal admissions for all four acute abdominal diseases were the highest in summer [acute appendicitis, (OR = 1.35; 95% CI = 1.28–1.43); diverticulitis, (OR = 1.23; 95% CI = 1.16–1.31; cholecystitis (OR = 1.23; 95% CI = 1.11–1.36); and cholangitis (OR = 1.23; 95% CI = 1.12–1.36)]. The proportion of patients with sepsis and disseminated intravascular coagulation as well as the total SOFA score for each disease, did not differ significantly across seasons. Seasonal variations in disease severity were not observed.

We have developed an encryption method using a computer-generated hologram (CGH) embedded in a dithered image. First, confidential information is converted into a CGH. Next, the CGH data undergo two separate dithering processes in parallel: one corresponding to CGH white pixels and one corresponding to CGH black pixels. The results from both processes are used to form a dither matrix for creating the final dithered and encoded image. In this way, confidential information can be embedded into the image. The confidential information can be extracted using a technique similar to CGH optical reconstruction.

Hydrogen storage by calcium nitride or magnesium nitride has been undertaken by the use of ammonia, in which the possibility of ammonia as a vector for hydrogen carriers has been studied. When the calcium imide ornitride obtained by thermal decomposition of calcium amide dispersed on active carbon (AC) was brought into contact with ammonia gas (300 Torr) at room temperature, NH3 uptake readily occurred. When the sample after NH3 uptake was heated, the absorbed ammonia was released in the form of hydrogen and nitrogen. The ammonia is possibly absorbed in the form of the decomposed state in the imide ornitride. This type of hydrogen storage has been extensively studied and characterized.For magnesium nitride, ammonia was absorbed and desorbed without the decomposition.

Recently, renewable energy technologies such as wind turbine generators and photovoltaic (PV) systems have been introduced as distributed generations (DGs). Connections of a large amount of distributed generations may cause voltage deviation beyond the statutory range in distribution systems. A reactive power control of DGs can be a solution of this problem, and it also has a possibility to reduce distribution loss. In this paper, we propose a control methodology of voltage profile in a distribution system using reactive power control of inverters interfaced with DGs and tap changing transformers. In the proposed method, a one‐day schedule of voltage references for the control devices are determined by an optimization technique based on predicted values of load demand and PV power generation. Reactive power control of interfaced inverters is implemented within the inverter capacity without reducing active power output. The proposed method accomplishes voltage regulation within the acceptable range and reduction of distribution loss. The effectiveness of the proposed method is confirmed by simulations. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.