Catalyst design, measurement guidelines, and device integration for H2O2 electrosynthesis from oxygen reduction

The electrosynthesis of H2O2 via a two-electron pathway oxygen reduction reaction (2e??? ORR) has emerged as a promising way of carbon-free and on-site production of H2O2. Active and selective electrocatalysts for the 2e??? ORR are essential for achieving high O2-to-H2O2 conversion efficiency. In this review, we present the recent progress in the development of 2e??? ORR electrocatalysts including Pt-group-metal (PGM) and non-PGM atomically dispersed catalysts and metal-free heteroatom-doped carbons. The impact of the active sites and interface structures on the electrocatalytic process is summarized. Benchmarking of the electrocatalytic activities in terms of O2-to-H2O2 mass activity and site-normalized activity is presented to understand the current status of advancement and to provide an insight into possible future research directions. In addition, some guidelines and pitfalls in typical laboratory measurements for assessing 2e??? ORR performance are proposed. Finally, recent advances in high-current-density H2O2 electrosynthesis reactors and devices that exploit electrosynthesized H2O2 are introduced

Predictors of Successful Trial without Catheter for Postoperative Urinary Retention Following Non-Urological Surgery

Purpose To investigate the success rate of trial without catheter (TWOC) for postoperative urinary retention (POUR) after non-urological surgery and to determine predictors of successful TWOC. Methods A total of 104 patients who underwent non-urological surgery and were referred to the department of urology for POUR were included in this retrospective study. All eligible patients underwent indwelling catheterization as an initial treatment and then TWOC was performed 3 to 7 days later. POUR was defined as micturition difficulty with greater than 400 mL of postvoid residual (PVR) urine volume measured by catheterization after non-urological surgery. Successful TWOC was defined as voiding with less than 100 mL of PVR urine volume. Predictive factors were identified by multivariate regression analysis. All definitions corresponded to recommendations of the International Continence Society. Results The mean age of the patients was 65.2 (range, 23 to 92) years. There were 45 male and 59 female patients. Intraoperative indwelling catheterization was performed in 69 (66.3%) patients. Mean duration of indwelling catheterization for POUR was 5.0 (range, 3.0 to 7.0) days and 83 (79.8%) patients received medication with an alpha-blocker. A successful TWOC was observed in 70 (67.4%) patients. The mean age of the patients with failure of TWOC was significantly higher than that of the patients with successful TWOC. The percentages of female patients, spinal surgery, and prone position during surgery in patients with unsuccessful TWOC were higher than in those with successful TWOC. In the multivariate logistic regression analysis, age and location of surgery (spine vs. non-spine) were the independent predictors of successful TWOC for POUR. Conclusions Our data suggest that older age and spinal surgery may be important risk factors for failure of TWOC for POUR after non-urological surgery. Thus, adequate prevention measures may be necessary for POUR after non-urological surgery, especially in patients with these risk factors

Glutaric Aciduria Type 1 in Korea: Report of Two Novel Mutations

Glutaric aciduria type I (GA I) is an autosomal recessive disorder caused by a deficiency of glutaryl-CoA dehydrogenase. Although over 400 patients confirmed as GA I have been reported, reports from the Asian population had contributed to the minor proportion. We recently diagnosed two cases of GA I confirmed with mutational analysis. Here, we present their rather atypical clinical presentations with genetic characteristics for the first time in Korea. Profound developmental delay from birth, association of hearing loss, and neurological improvement after surgical intervention, were considered to be different clinical features from most reported cases. One patient was a compound heterozygote for p.Ser139Leu and p.Asp220Tyr, and the other for p.Ser139Leu and Glu160X. The mutations of the two alleles (p.Asp220Tyr and p.Glu160X) were novel and reports of p.Ser139Leu were rare both in Western and other Asian populations. These might suggest different genetic spectrum of Korean GA I patients

Assessment of Bone Quality using Finite Element Analysis Based upon Micro-CT Images

BACKGROUND: To evaluate the feasibility of a micro-image based finite element model to determine the efficacy of sequential treatments on the bone quality in a rat osteoporosis model. METHODS: Rat osteoporosis and treated osteoporosis models were established with the bone loss, restore and maintain concept. Thirty Sprague-Dawley rats were used in this study. A sham operation or ovariectomy was performed at 20 weeks after birth, which was followed by the respective sequential trials as follows: (1) sham-operation only, (2) ovariectomy only, (3) ovariectomized rats with parathyroid hormone maintenance, (4) ovariectomized rats treated with PTH for 5 weeks and then withdrawal, (5) ovariectomized rats treated with PTH for 5 weeks and then with 17 beta-estradiol, and (6) ovariectomized rats treated with parathyroid hormone for 5 weeks and then treated with zoledronate. The histomorphometry indices were determined using the micro-images from a micro-computed tomogram. Finite element analysis was carried out to determine the mechanical properties (Stiffness and Young's modulus) of the vertebra bodies. The differences in properties between the groups were compared using ANOVA and a Bonferroni's multiple group comparison procedure. RESULTS: The histomorphometry and mechanical properties were significantly better in groups (3) and (6) than in the groups (1) and (2) (p < 0.05). The stiffness (sigma(s)) and Young's modulus (E) was highest in group (3) following by group (6). CONCLUSIONS: Finite element analysis based on micro-images provides a useful tool that reflects the changes in micro-structural and mechanical properties of a rat vertebral body with the bone loss, restore and maintain concept.ope

Electroless Gold Plating on Aluminum Patterned Chips for CMOS-based Sensor Applications

We presented an approach for the activation of aluminum Al alloy using palladium Pd and the subsequent gold Au electroless plating ELP for complementary metal oxide semiconductor CMOS -based sensor applications. In this study, CMOS process compatible Al patterned chips were used as substrates for easy incorporation with existing CMOS circuits. To improve the contact resistance that arose from the Schottky barrier between the metal electrodes and the single-walled carbon nanotubes SWCNTs , electroless deposition of gold that has a higher work function than Al was adopted because the SWCNTs has p-type semiconductor properties. Each step of the Au ELP procedure was studied under various bath temperatures, immersion times, and chemical concentrations. Fine Pd particles were homogeneously distributed on the Al surface by the Pd activation process at room temperature. Au ELP allowed selective deposition of the Au film on the activated Al surface only. The SWCNT networks formed on the Au plated chip by a dip-coating method showed improved contact resistance and resistance variation between the Au electrode and SWCNTs. We also tried SWCNT decoration with the Au particle using the upper Au ELP method, which was expected to be applied in various areas including field-effect transistors and sensor devices.This work was supported by the Nano Systems Institute-National Core Research Center NSI-NCRC program of NRF and the TDPAF, Ministry for Agriculture, Forestry and Fisheries, Republic of Korea

Screening of Brain Metastasis with Limited Magnetic Resonance Imaging (MRI): Clinical Implications of Using Limited Brain MRI During Initial Staging for Non-small Cell Lung Cancer Patients

The purpose of this prospective study was to determine whether using magnetic resonance imaging (MRI) for early screening for brain metastases (BM) can improve quality of life, survival in patients with non-small cell lung cancer (NSCLC). The study group comprised 183 patients newly diagnosed with NSCLC. All patients underwent limited brain MRI and routine workups. The control group comprised 131 patients with NSCLC who underwent limited brain MRI only if they had neurologic symptoms. The incidence of BM was 20.8% (38/183) in the study group and 4.6% (6/131) in the control group. The rate of upstaging based on the MRI data was 13.5% (15/111) overall and 15.9% (11/69) in patients that had been considered initially to be resectable surgically. There was no significant difference in survival outcome between the groups. Patients who had BM alone had a greater overall survival time (49 weeks) than those who had multiple systemic metastases (27 weeks; p=0.0307). In conclusions, limited brain MRI appears to be a useful, cost-effective method to screen for BM at the time of initial staging. And it may facilitate timely treatment of patients with NSCLC and improve their survival and quality of life

Efficacy and Tolerability of Peginterferon Alpha Plus Ribavirin in the Routine Daily Treatment of Chronic Hepatitis C Patients in Korea: A Multi-Center, Retrospective Observational Study

Background/Aims: We aimed to evaluate the efficacy and safety of peginterferon plus ribavirin for chronic hepatitis C (CHC) patients under real life setting in Korea. Methods: We retrospectively analyzed the medical records of 758 CHC patients treated with peginterferon plus ribavirin between 2000 and 2008 from 14 university hospitals in the Gyeonggi-Incheon area in Korea. Results: Hepatitis C virus (HCV) genotype 1 was detected in 61.2% of patients, while genotype 2 was detected in 35.5%. Baseline HCV RNA level was &gt;= 6x10(5) IU/mL in 51.6% of patients. The sustained virological response (SVR) rate was 59.6% regardless of genotype; 53.6% in genotype 1 and 71.4% in genotype 2/3. On multivariate analysis, male gender (p=0.011), early virological response (p&lt;0.001), genotype 2/3 (p&lt;0.001), HCV RNA &lt;6x10(5) IU/mL (p=0.005) and adherence to the drug &gt;80% of the planned dose (p&lt;0.001) were associated with SVR. The rate of premature discontinuation was 35.7%. The main reason for withdrawal was intolerance to the drug due to common adverse events or cytopenia (48.2%). Conclusions: Our data suggest that the efficacy of peginterferon and ribavirin therapy in Koreans is better in Koreans than in Caucasians for the treatment of CHC, corroborating previous studies that have shown the superior therapeutic efficacy of this regimen in Asians.This study was supported by the Korean Association for the Study of the Liver in 2009