Synthesis of Metal Oxide Decorated Polycarboxyphenyl Polymer-Grafted Multiwalled Carbon Nanotube Composites by a Chemical Grafting Approach for Supercapacitor Application

We present grafting of polycarboxyphenyl polymer on the surface of multiwalled carbon nanotube (MWCNT) via a free radical polymerization and subsequent anchoring of the metal oxide nanoparticles for the evaluation of their potential applicability to supercapacitor electrodes. Here, metal oxide nanoparticles, Fe3O4 and Sm2O3, were created after the oxidation of metal precursors Sm(NO3)3 and FeCl2, respectively, and attached on the surface of polycarboxyphenyl-grafted MWCNT (P-CNT) in aqueous medium. This approach shows a potential for enhancing the dispersion of Fe3O4 and Sm2O3 nanoparticles on the wall of P-CNT. The structure and morphological characteristics of the purified MWCNT, P-CNT, and metal oxide-anchored polycarboxyphenyl-grafted MWCNT (MP-CNT) nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The electrochemical performance of the purified MWCNT electrode, P-CNT electrode, and MP-CNT electrodes was tested by cyclic voltammetry (CV) and galvanostatic charge discharge in a 1.0 M H2SO4 aqueous electrolyte. The results showed that the specific capacitance of the purified MWCNT was 45.3 F/g at the scan rate of 5 mV/s and increased to 54.1 F/g after the modification with polycarboxyphenyl polymer. Further modification of P-CNT with Sm2O3 and Fe3O4 improved the specific capacitance of 65.84 F/g and 173.38 F/g, respectively, at the same scan rate

Enhancement on Radon Adsorption Property of GAC using Nano-size Carbon Colloids

Granular activated carbon (GAC) is well-known as an efficient adsorbent against a number of gaseous pollutants. Radon is one of those pollutants, and radon has been classified as the second leading cause of lung cancer in USA. This study was to enhance the radon removal efficiency with applying nano-technology. Nano-size carbon colloids (NCC) was produced through electrolysis which is simple and cheap. NCC was used for impregnation with activated carbon. Surface areas of both NCC-treated and non-treated activated carbon did not show a significant difference. However, the results of radon removal efficiency show that impregnated carbon with NCC could capture about 1.3 ~ 2 times of more radon gas compared to non-treated activated carbon. It is assumed that nano-size carbon colloids might have filled up meso-pores, and meso-pores turned into micro-pores eventually. Because meso-pores initially accounted for large portion of whole pores, more radon could be captured to NCC-impregnated activated carbon. Keywords: Radon, Nano-Size Carbon Collid, Activated Carbo

Toward Green Synthesis of Graphene Oxide Using Recycled Sulfuric Acid via Couette-Taylor Flow

Developing eco-friendly and cost-effective processes for the synthesis of graphene oxide (GO) is essential for its widespread industrial applications. In this work, we propose a green synthesis technique for GO production using recycled sulfuric acid and filter-processed oxidized natural graphite obtained from a Couette-Taylor flow reactor. The viscosity of reactant mixtures processed from Couette-Taylor flow was considerably lower (???200 cP at 25 ??C) than that of those from Hummers' method, which enabled the simple filtration process. The filtered sulfuric acid can be recycled and reused for the repetitive GO synthesis with negligible differences in the as-synthesized GO qualities. This removal of sulfuric acid has great potential in lowering the overall GO production cost as the amount of water required during the fabrication process, which takes a great portion of the total production cost, can be dramatically reduced after such acid filtration. The proposed eco-friendly GO fabrication process is expected to promote the commercial application of graphene materials into industry shortly

Stress-induced nuclear translocation of CDK5 suppresses neuronal death by downregulating ERK activation via VRK3 phosphorylation

Although extracellular signal-related kinase 1/2 (ERK 1/2) activity is generally associated with cell survival, prolonged ERK activation induced by oxidative stress also mediates neuronal cell death. Here we report that oxidative stress-induced cyclin-dependent kinase 5 (CDK5) activation stimulates neuroprotective signaling via phosphorylation of vaccinia-related kinase 3 (VRK3) at Ser 108. The binding of vaccinia H1-related (VHR) phosphatase to phosphorylated VRK3 increased its affinity for phospho-ERK and subsequently downregulated ERK activation. Overexpression of VRK3 protected human neuroblastoma SH-SY5Y cells against hydrogen peroxide (H2O2)-induced apoptosis. However the CDK5 was unable to phosphorylate mutant VRK3, and thus the mutant forms of VRK3 could not attenuate apoptotic process. Suppression of CDK5 activity results in increase of ERK activation and elevation of proapoptotic protein Bak expression in mouse cortical neurons. Results from VRK3-deficient neurons were further confirmed the role of VRK3 phosphorylation in H2O2-evoked ERK regulation. Importantly, we showed an association between phospho-VRK3 levels and the progression of human Alzheimer’s disease (AD) and Parkinson’s disease (PD). Together our work reveals endogenous protective mechanism against oxidative stress-induced neuronal cell death and suggest VRK3 as a potential therapeutic target in neurodegenerative diseases.1186Ysciescopu

Quadruple 9-mer-based protein binding microarray with DsRed fusion protein

<p>Abstract</p> <p>Background</p> <p>The interaction between a transcription factor and DNA motif (<it>cis</it>-acting element) is an important regulatory step in gene regulation. Comprehensive genome-wide methods have been developed to characterize protein-DNA interactions. Recently, the universal protein binding microarray (PBM) was introduced to determine if a DNA motif interacts with proteins in a genome-wide manner.</p> <p>Results</p> <p>We facilitated the PBM technology using a DsRed fluorescent protein and a concatenated sequence of oligonucleotides. The PBM was designed in such a way that target probes were synthesized as quadruples of all possible 9-mer combinations, permitting unequivocal interpretation of the <it>cis</it>-acting elements. The complimentary DNA strands of the features were synthesized with a primer and DNA polymerase on microarray slides. Proteins were labeled via N-terminal fusion with DsRed fluorescent protein, which circumvents the need for a multi-step incubation. The PBM presented herein confirmed the well-known DNA binding sequences of Cbf1 and CBF1/DREB1B, and it was also applied to elucidate the unidentified <it>cis</it>-acting element of the OsNAC6 rice transcription factor.</p> <p>Conclusion</p> <p>Our method demonstrated PBM can be conveniently performed by adopting: (1) quadruple 9-mers may increase protein-DNA binding interactions in the microarray, and (2) a one-step incubation shortens the wash and hybridization steps. This technology will facilitate greater understanding of genome-wide interactions between proteins and DNA.</p

An 18-year experience of tracheoesophageal fistula and esophageal atresia

PurposeTo determine the clinical manifestations and outcomes of patients with tracheoesophageal fistula (TEF) and esophageal atresia (EA) born at a single neonatal intensive care unit.MethodsA retrospective analysis was conducted for 97 patients with confirmed TEF and EA who were admitted to the neonatal intensive care unit between 1990 and 2007.ResultsThe rate of prenatal diagnosis was 12%. The average gestational age and birth weight were 37+2 weeks and 2.5±0.7 kg, respectively. Thirty-one infants were born prematurely (32%). Type C was the most common. The mean gap between the proximal and distal esophagus was 2 cm. Esophago-esophagostomy was performed in 72 patients at a mean age of 4 days after birth; gastrostomy or duodenostomy were performed in 8 patients. Forty patients exhibited vertebral, anorectal, cardiac, tracheoesophageal, renal, limb (VACTERL) association with at least 2 combined anomalies, and cardiac anomaly was the most common. The most common post-operative complications were esophageal stricture followed by gastroesophageal reflux. Balloon dilatation was performed for 1.3 times in 26 patients at a mean age of 3 months. The mortality and morbidity rates were 24% and 67%, respectively, and the most common cause of death was sepsis. The weight of approximately 40% patients was below the 10th percentile at 2 years of age.ConclusionMortality and morbidity rates of patients with TEF and EA are high as compared to those of infants with other neonatal surgical diseases. Further efforts must be taken to reduce mortality and morbidity and improve growth retardation

A Case of Hepatocellular Carcinoma Within Hepatocellular Adenoma in a Non-Cirrhotic Male

Hepatocellular adenoma (HA) is a benign hepatic lesion that predominantly occurs in young women. Most hepatocellular carcinomas (HCC) arise in a cirrhotic liver during the fifth or sixth decades. There have been several reported cases of HCC developing from HA in female patients. However, there are rare cases about HCC arising in HA in a non-cirrhotic male patient. We have recently encountered a 53-year-old man who had a liver mass in a non-cirrhotic liver, and the liver mass was compatible with HA on the pre-operative computed tomography. The mass was completely resected and the histopathology revealed a focus of HCC arising in HA. We report here on this case along with a brief review of the relevant literature