144 research outputs found

    Incipient piezoelectrics and electrostriction behavior in Sn-doped Bi-1/2( Na0.82K0.18)(1/2) TiO3 lead-free ceramics

    Get PDF
    Dielectric, ferroelectric, piezoelectric, and strain properties of lead-free Sn-doped Bi-1/2(Na0.82K0.18)(1/2)TiO3 (BNKT) were investigated. A crossover from a nonergodic relaxor to an ergodic relaxor state at room temperature, accompanied by a giant electric-field-induced strain, was observed at 5 at. % Sn doping. Switching dynamics monitored during a bipolar poling cycle manifested that the observed giant strain originates from incipient piezoelectricity. When Sn doping level reached 8 at. %, BNKT exhibited an electrostrictive behavior with a highly temperature-insensitive electrostrictive coefficient of Q(11) = 0.023 m(4)open3

    Ring-Type Rotary Ultrasonic Motor Using Lead-free Ceramics

    Get PDF
    Ultrasonic motors provide high torques and quick responses compared to their magnetic counterparts; therefore, they are widely used in small-scale applications such as mobile phones, microrobots, and auto-focusing modules in digital cameras. To determine the feasibility of lead-free piezoceramics for ultrasonic motor applications, we fabricated a ring-type piezoceramic with a KNN-based lead-free piezoceramic (referred to as CZ5), intended for use in an auto-focusing module of a digital camera. The vibration of the lead-free stator was observed at 45.1kHz. It is noteworthy that the fully assembled lead-free ultrasonic motor exhibited a revolution speed of 5-7 rpm, even though impedance matching with neighboring components was not considered. This result suggests that the tested KNN-based piezoceramic has great potential for use in ultrasonic motor applications, requiring minimal modifications to existing lead-based systems.ope

    Central Pontine Myelinolysis in a Patient with Acute Lymphoblastic Leukemia after Hematopoietic Stem Cell Transplantation: A Case Report

    Get PDF
    We describe a 37-yr-old man who developed central pontine myelinolysis (CPM) after allogeneic hematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukemia. After HSCT, desquamation developed on the whole body accompanied by hyperbilirubinemia. The liver biopsy of the patient indicated graft-versus-host disease-related liver disease, and the dose of methylprednisolone was increased. Then, the patient developed altered mentality with eye ball deviation to the left, for which electroencephalogram and magnetic resonance imaging (MRI) scans were done. Brain MRI scan demonstrated the imaging findings consistent with central pontine myelinolysis and extrapontine myelinolysis. He did not have any hyponatremia episode during hospitalization prior to the MRI scan. To the best of our knowledge, presentation of CPM after allogeneic HSCT is extremely rare in cases where patients have not exhibited any episodes of significant hyponatremia. We report a rare case in which hepatic dysfunction due to graft-versus-host disease has a strong association with CPM after HSCT

    Effects and Safety of Gyejibongnyeong-Hwan on Dysmenorrhea Caused by Blood Stagnation: A Randomized Controlled Trial

    Get PDF
    Objective. This study was a multicenter, randomized, double-blind, and controlled trial with two parallel arms: the GJBNH group and the placebo group. This trial recruited 100 women aging 18 to 35 years with primary dysmenorrhea caused by blood stagnation. The investigational drugs, GJBNH or placebo, were administered for two menstrual periods (8 weeks) to the participants three times per day. The participants were followed up for two menstrual cycles after the administration. Results. The results were analyzed by the intention-to-treat (ITT) dataset and the per-protocol (PP) dataset. In the ITT dataset, the change of the average menstrual pain VAS score in the GJBNH group was statistically significantly lower than that in the control group. Significant difference was not observed in the SF-MPQ score change between the GJBNH group and the placebo group. No significant difference was observed in the PP analyses. In the follow-up phase, the VAS scores of the average menstrual pain and the maximum menstrual pain continually decreased in the placebo group, but they increased in the GJBNH group. Conclusion. GJBNH treatment for eight weeks improved the pain of the dysmenorrhea caused by blood stagnation, but it should be successively administered for more than two menstrual cycles. Trial Registration. This trial is registered with Current Controlled Trials no. ISRCTN30426947

    Perinatal Outcome in Twin Pregnancies Complicated by Gestational Diabetes Mellitus: A Comparative Study

    Get PDF
    The purpose of this study is to compare perinatal outcomes of twin pregnancies complicated by gestational diabetes (GDM) with those unaffected by GDM. A total of 1,154 twin pregnancies who delivered at Cheil General Hospital, between January 1998 and December 2002 were recruited to participate in a retrospective analysis. Out of these twin pregnancies, 37 women were had GDM. Four pregnancies exposed to GDM were excluded due to the loss of medical records; therefore 33 twin pregnancies exposed to GDM were enrolled. We matched the GDM pregnancies with pregnancies unaffected by GDM in a 1:2 ratio; therefore there were 33 GDM/66 without GDM who delivered during the study period. Our findings show that there were no significant differences including birth weight, Apgar score, respiratory distress syndrome, meconium aspiration pneumonia, transient tachypnea of new born, hyperbilirubinemia, hypoglycemia, hypocalcemia and congenital anomalies. Therefore, well controlled GDM may not increase perinatal complications in twin pregnancies. Careful pregnancy management and fetal surveillance in twin pregnancies is important to decrease perinatal complications and maintain a sound pregnancy and healthy offspring

    Autophagy deficiency leads to protection from obesity and insulin resistance by inducing Fgf21 as a mitokine

    Get PDF
    Despite growing interest and a recent surge in papers, the role of autophagy in glucose and lipid metabolism is unclear. We produced mice with skeletal muscle–specific deletion of Atg7 (encoding autophagy-related 7). Unexpectedly, these mice showed decreased fat mass and were protected from diet-induced obesity and insulin resistance; this phenotype was accompanied by increased fatty acid oxidation and browning of white adipose tissue (WAT) owing to induction of fibroblast growth factor 21 (Fgf21). Mitochondrial dysfunction induced by autophagy deficiency increased Fgf21 expression through induction of Atf4, a master regulator of the integrated stress response. Mitochondrial respiratory chain inhibitors also induced Fgf21 in an Atf4-dependent manner. We also observed induction of Fgf21, resistance to diet-induced obesity and amelioration of insulin resistance in mice with autophagy deficiency in the liver, another insulin target tissue. These findings suggest that autophagy deficiency and subsequent mitochondrial dysfunction promote Fgf21 expression, a hormone we consequently term a 'mitokine', and together these processes promote protection from diet-induced obesity and insulin resistance

    Favorable short-term oncologic outcomes following laparoscopic surgery for small T4 colon cancer: a multicenter comparative study

    Get PDF
    Background Laparoscopic surgery for T4 colon cancer may be safe in selected patients. We hypothesized that small tumor size might preoperatively predict a good laparoscopic surgery outcome. Herein, we compared the clinicopathologic and oncologic outcomes of laparoscopic and open surgery in small T4 colon cancer. Methods In a retrospective multicenter study, we reviewed the data of 449 patients, including 117 patients with tumors ≤ 4.0 cm who underwent surgery for T4 colon cancer between January 2014 and December 2017. We compared the clinicopathologic and 3-year oncologic outcomes between the laparoscopic and open groups. Survival curves were estimated using the Kaplan–Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox proportional hazards model. A p < 0.05 was considered statistically significant. Results Blood loss, length of hospital stay, and postoperative morbidity were lower in the laparoscopic group than in the open group (median [range], 50 [0–700] vs. 100 [0–4000] mL, p < 0.001; 8 vs. 10 days, p < 0.001; and 18.0 vs. 29.5%, p = 0.005, respectively). There were no intergroup differences in 3-year overall survival or disease-free survival (86.6 vs. 83.2%, p = 0.180, and 71.7 vs. 75.1%, p = 0.720, respectively). Among patients with tumor size ≤ 4.0 cm, blood loss was significantly lower in the laparoscopic group than in the open group (median [range], 50 [0–530] vs. 50 [0–1000] mL, p = 0.003). Despite no statistical difference observed in the 3-year overall survival rate (83.3 vs. 78.7%, p = 0.538), the laparoscopic group had a significantly higher 3-year disease-free survival rate (79.2 vs. 53.2%, p = 0.012). Conclusions Laparoscopic surgery showed similar outcomes to open surgery in T4 colon cancer patients and may have favorable short-term oncologic outcomes in patients with tumors ≤ 4.0 cm.This work was supported by the Clinical Research Program of the National Cancer Center (grant number NCC 2011520-1)

    Patient Descriptions of Rectal Effluents May Help to Predict the Quality of Bowel Preparation With Photographic Examples

    Get PDF
    Background/AimsPrevious studies have suggested a weak correlation between self-reported rectal effluent status and bowel preparation quality. We aim to evaluate whether photographic examples of rectal effluents could improve the correlation between patient descriptions of rectal effluents and bowel preparation quality.MethodsBefore colonoscopy, patients were asked to describe the nature of their last three rectal effluents. Photographic examples of rectal effluents were provided as a reference for scoring. Bowel preparation was subsequently assessed by a single endoscopist using a global preparation assessment scale. Preparation outcomes were grouped into two levels (excellent to good vs. fair to inadequate). Both univariate and multivariate logistic regression models were used to find any association between bowel preparation quality and patient characteristics.ResultsA total of 138 patients completed the questionnaires. The mean age was 56.5±10.4 years. The mean sum of the last three rectal effluent scores was 5.9±2.0. Higher rectal effluent scores (odds ratio [OR], 0.82; P=0.043) and the presence of diverticula (OR, 0.16; P<0.001) were risk factors for suboptimal preparation.ConclusionsPhotographic example-guided patient descriptions of rectal effluents showed a statistically significant association with bowel preparation quality. However, clinical significance seemed to be low. The presence of diverticula was an independent predictive factor for suboptimal bowel preparation quality

    Kidney Health Plan 2033 in Korea: bridging the gap between the present and the future

    Get PDF
    In response to the increase in the prevalence of chronic kidney disease (CKD) in Korea, the growth of patients requiring renal replacement therapy and the subsequent increase in medical costs, the rapid expansion of patients with end-stage kidney disease (ESKD), and the decrease in patients receiving home therapy, including peritoneal dialysis, the Korean Society of Nephrology has proclaimed the new policy, Kidney Health Plan 2033 (KHP 2033). KHP 2033 would serve as a milestone to bridge the current issues to a future solution by directing the prevention and progression of CKD and ESKD, particularly diabetic kidney disease, and increasing the proportion of home therapy, thereby reducing the socioeconomic burden of kidney disease and improving the quality of life. Here, we provide the background for the necessity of KHP 2033, as well as the contents of KHP 2033, and enlighten the Korean Society of Nephrology’s future goals. Together with patients, healthcare providers, academic societies, and national policymakers, we need to move forward with goal-oriented drive and leadership to achieve these goals
    corecore