Effect of Varying the Semiconducting/Metallic Tube Ratio on the Performance of Mixed Single-Walled Carbon Nanotube Network Gas Sensors

The sensing properties of mixed networks consisting of semiconducting and metallic single-walled carbon nanotubes (SWCNTs) have been found to largely vary depending on the ratio of semiconducting to metallic tubes. Solution-deposited 99% semiconductor-enriched nanotube networks exhibited a sensitivity of 1.908%/ppm, whereas the unenriched 66% and 90% enriched samples exhibited a sensitivity of 0.027%/ppm and 0.113%/ppm, respectively. These results suggest that it is extremely important to minimize the metallic pathways to achieve high sensitivity. After an oxygen plasma treatment, the unenriched 66% sample exhibited a 526% increase in sensitivity (0.142%/ppm) compared to the untreated one, whereas the 90% device demonstrated a sensitivity of 1.521%/ppm, which corresponds to an improvement in the sensitivity of 13.5 times the pristine 90% sample. In addition, the plasma-treated sensors exhibited a much faster response time than the untreated one. The significant improvement in the performance of the highly enriched network sensors was explained by the large increase in the anchoring sites for ammonia molecules on the surface of the semiconducting single-walled CNTs and the faster charge transfer from absorbed molecules

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

Predictors of cervical myelopathy and hydrocephalus in young children with achondroplasia

Background Cervical myelopathy and hydrocephalus occasionally occur in young children with achondroplasia. However, these conditions are not evaluated in a timely manner in many cases. The current study presents significant predictors for cervical myelopathy and hydrocephalus in young children with achondroplasia. Methods A retrospective analysis of 65 patients with achondroplasia who visited Seoul National University Childrens Hospital since 2012 was performed. The patients were divided into groups according to the presence of cervical myelopathy and hydrocephalus, and differences in foramen magnum parameters and ventricular parameters by magnetic resonance imaging between groups were analyzed. Predictors for cervical myelopathy and hydrocephalus were analyzed, and the cut-off points for significant ones were calculated. Results The group with cervical myelopathy showed foramen magnum parameters that indicated significantly lower cord thickness than in the group without cervical myelopathy, and the group with hydrocephalus showed significantly higher ventricular parameters and Posterior indentation grade than the group without hydrocephalus. Cord constriction ratio (OR 5199.90, p = 0.001) for cervical myelopathy and Frontal horn width (OR 1.14, p = 0.001) and Posterior indentation grade (grade 1: OR 9.25, p = 0.06; grade 2: OR 18.50, p = 0.01) for hydrocephalus were significant predictors. The cut-off points for cervical myelopathy were Cord constriction ratio of 0.25 and FM AP of 8 mm (AUC 0.821 and 0.862, respectively) and Frontal horn width of 50 mm and Posterior indentation grade of 0 (AUC 0.788 and 0.758, respectively) for hydrocephalus. Conclusion Cord constriction ratio for cervical myelopathy and Frontal horn width and Posterior indentation grade for hydrocephalus were significant predictors and may be used as useful parameters for management. Posterior indentation grade may also be used to determine the treatment method for hydrocephalus

Enhancement of phase separation in the InGaN layer for self-assembled In-rich quantum dots

The enhancement of phase separation in the InGaN layer grown on a GaN layer with a rough surface was investigated for the formation of self-assembled In-rich quantum dots(QDs) in the InGaN layer. Transmission electron microscopy images showed that In-rich QDs with a size of 2–5 nm were formed even in an InGaN layer with a low indium content, and a layer thickness less than the critical thickness. The room-temperature photoluminescence(PL) spectrum of this layer showed emission peaks corresponding to In-rich QDs. The temperature-dependent PL spectra showed dominant peak shifts to the lower energy side, indicating that the self-assembled In-rich QDs are formed in the InGaN layer grown on a rough GaNsurface and that the carriers are localized in In-rich QDs

The role of adjuvant pelvic radiotherapy in rectal cancer with synchronous liver metastasis: a retrospective study

<p>Abstract</p> <p>Background</p> <p>Synchronous liver metastases are detected in approximately 25% of colorectal cancer patients at diagnosis. The rates of local failure and distant metastasis are substantial in these patients, even after undergoing aggressive treatments including resection of primary and metastatic liver tumors. The purpose of this study was to determine whether adjuvant pelvic radiotherapy is beneficial for pelvic control and overall survival in rectal cancer patients with synchronous liver metastasis after primary tumor resection.</p> <p>Methods</p> <p>Among rectal cancer patients who received total mesorectal excision (TME) between 1997 and 2006 at Yonsei University Health System, eighty-nine patients diagnosed with synchronous liver metastasis were reviewed. Twenty-seven patients received adjuvant pelvic RT (group S + R), and sixty-two patients were managed without RT (group S). Thirty-six patients (58%) in group S and twenty patients (74%) in group S+R received local treatment for liver metastasis. Failure patterns and survival outcomes were analyzed.</p> <p>Results</p> <p>Pelvic failure was observed in twenty-five patients; twenty-one patients in group S (34%), and four patients in group S+R (15%) (<it>p </it>= 0.066). The two-year pelvic failure-free survival rates (PFFS) of group S and group S+R were 64.8% and 80.8% (<it>p </it>= 0.028), respectively, and the two-year overall survival rates (OS) were 49.1% and 70.4% (<it>p </it>= 0.116), respectively. In a subgroup analysis of fifty-six patients who received local treatment for liver metastasis, the two-year PFFS were 64.9% and 82.9% (<it>p </it>= 0.05), respectively; the two-year OS were 74.1% and 80.0% (<it>p </it>= 0.616) in group S (n = 36) and group S+R (n = 20), respectively.</p> <p>Conclusions</p> <p>Adjuvant pelvic RT significantly reduced the pelvic failure rate but its influence on overall survival was unclear. Rectal cancer patients with synchronous liver metastasis may benefit from adjuvant pelvic RT through an increased pelvic control rate and improved quality of life.</p

Synthesis of large-area multilayer hexagonal boron nitride for high material performance

Although hexagonal boron nitride (h-BN) is a good candidate for gate-insulating materials by minimizing interaction from substrate, further applications to electronic devices with available two-dimensional semiconductors continue to be limited by flake size. While monolayer h-BN has been synthesized on Pt and Cu foil using chemical vapour deposition (CVD), multilayer h-BN is still absent. Here we use Fe foil and synthesize large-area multilayer h-BN film by CVD with a borazine precursor. These films reveal strong cathodoluminescence and high mechanical strength (Young’s modulus: 1.16±0.1 TPa), reminiscent of formation of high-quality h-BN. The CVD-grown graphene on multilayer h-BN film yields a high carrier mobility of ~24,000 cm[superscript 2] V[superscript −1] s[superscript −1] at room temperature, higher than that (~13,000 [superscript 2] V[superscript −1] s[superscript −1]) with exfoliated h-BN. By placing additional h-BN on a SiO[subscript 2]/Si substrate for a MoS[subscript 2] (WSe[subscript 2]) field-effect transistor, the doping effect from gate oxide is minimized and furthermore the mobility is improved by four (150) times.Korea Institute of Science and Technology. Institutional ProgramNational Science Foundation (U.S.) (STC Center for Integrated Quantum Materials Grant DMR-1231319)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologie

Protective Effect of the Fruit Hull of Gleditsia sinensis on LPS-Induced Acute Lung Injury Is Associated with Nrf2 Activation

The fruit hull of Gleditsia sinensis (FGS) has been prescribed as a traditional eastern Asian medicinal remedy for the treatment of various respiratory diseases, but the efficacy and underlying mechanisms remain poorly characterized. Here, we explored a potential usage of FGS for the treatment of acute lung injury (ALI), a highly fatal inflammatory lung disease that urgently needs effective therapeutics, and investigated a mechanism for the anti-inflammatory activity of FGS. Pretreatment of C57BL/6 mice with FGS significantly attenuated LPS-induced neutrophilic lung inflammation compared to sham-treated, inflamed mice. Reporter assays, semiquantitative RT-PCR, and Western blot analyses show that while not affecting NF-κB, FGS activated Nrf2 and expressed Nrf2-regulated genes including GCLC, NQO-1, and HO-1 in RAW 264.7 cells. Furthermore, pretreatment of mice with FGS enhanced the expression of GCLC and HO-1 but suppressed that of proinflammatory cytokines in including TNF-α and IL-1β in the inflamed lungs. These results suggest that FGS effectively suppresses neutrophilic lung inflammation, which can be associated with, at least in part, FGS-activating anti-inflammatory factor Nrf2. Our results suggest that FGS can be developed as a therapeutic option for the treatment of ALI