Chung-Ang University

About: Chung-Ang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Thin film. The organization has 13381 authors who have published 26978 publications receiving 416735 citations. The organization is also known as: CAU & Chung.

Effects of one- and two-dimensional carbon hybridization of PEDOT:PSS on the power factor of polymer thermoelectric energy conversion devices

Abstract: We investigated the thermoelectric properties of polymer composites based on a conducting polymer and carbon materials with various dimensionalities. PEDOT:PSS as a conducting polymer matrix was successfully hybridized with graphene sheets and multi-walled carbon nanotubes through in situ polymerization of 3,4-ethlyenedioxythiophene monomers in an aqueous solution in the presence of the carbon materials dispersed by using a polymeric dispersant. The hybrid structures of PEDOT:PSS, graphene, and carbon nanotubes in the composite showed an electrical conductivity, Seebeck coefficient, and power factor of 689 S cm−1, 23.2 μV K−1, and 37.08 μW mK−2, respectively, values that are much higher than those of pristine PEDOT:PSS, PEDOT:PSS/graphene, or PEDOT:PSS/carbon-nanotube composites. The thermoelectric figure of merit increased from 0.017 in the pristine PEDOT:PSS to 0.031 in the composite, corresponding to an 80% enhancement. We believe that the enhanced thermoelectric performance comes from the synergic effects of multi-component systems with excellent electrical bridging and electronic coupling between PEDOT and carbon materials.

Block-Copolymer-Assisted One-Pot Synthesis of Ordered Mesoporous WO3−x/Carbon Nanocomposites as High-Rate-Performance Electrodes for Pseudocapacitors

Abstract: An ordered mesoporous tungsten-oxide/carbon (denoted as m-WO3−x-C-s) nanocomposite is synthesized using a simple one-pot method using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) as a structure-directing agent. The hydrophilic PEO block interacts with the carbon and tungsten precursors (resol polymer and WCl6), and the PS block is converted to pores after heating at 700 °C under a nitrogen flow. The m-WO3−x-C-s nanocomposite has a high Brunauer–Emmett–Teller (BET) surface area and hexagonally ordered pores. Because of its mesoporous structure and high intrinsic density of tungsten oxide, this material exhibits a high average volumetric capacitance and gravimetric capacitance as a pseudocapacitor electrode. In comparison with reduced mesoporous tungsten oxide (denoted as m-WO3−x-h), which is synthesized by a tedious hard template approach and further reduction in a H2/N2 atmosphere, m-WO3−x-C-s shows a high capacitance and enhanced rate performance, as confirmed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The good performance of m-WO3−x-C-s is attributed to the high surface area arising from the mesoporous structure, the large interconnected mesopores, and the low internal resistance from the well-dispersed reduced tungsten oxide and amorphous carbon composite structure. Here, the amorphous carbon acts as an electrical pathway for effective pseudocapacitor behavior of WO3-x.

Pretreatment with Cisplatin Enhances E7-Specific CD8+ T-Cell–Mediated Antitumor Immunity Induced by DNA Vaccination

Abstract: Purpose: Because the combination of multiple modalities for cancer treatment is more likely to generate more potent therapeutic effects for the control of cancer, we have explored the combination of chemotherapy using cisplatin, which is routinely used in chemotherapy for advanced cervical cancer, with immunotherapy using DNA vaccines encoding calreticulin (CRT) linked to human papillomavirus type 16 E7 antigen (CRT/E7) in a preclinical model. Experimental Design: We characterized the combination of cisplatin with CRT/E7 DNA vaccine using different regimen for its potential ability to generate E7-specific CD8+ T-cell immune responses as well as antitumor effects against E7-expressing tumors. Results: Our results indicate that treatment of tumor-bearing mice with chemoimmunotherapy combining cisplatin followed by CRT/E7 DNA generated the highest E7-specific CD8+ T-cell immune response and produced the greatest antitumor effects and long-term survival as well as significant levels of E7-specific tumor-infiltrating lymphocytes compared with all the other treatment regimens. Furthermore, we found that treatment with cisplatin leads to the cell-mediated lysis of E7-expressing tumor cells in vitro and increased number of E7-specific CD8+ T-cell precursors in tumor-bearing mice. In addition, we observed that E7-specific CD8+ T cells migrate to and proliferate in the location of TC-1 tumors in mice treated with cisplatin. Conclusions: Thus, our data suggest that chemoimmunotherapy using cisplatin followed by CRT/E7 DNA vaccine is an effective treatment against E7-expressing tumors and may potentially be translated into the clinical arena.

Disc height and segmental motion as risk factors for recurrent lumbar disc herniation.

Abstract: STUDY DESIGN Retrospective review and multivariate analysis OBJECTIVES Recurrent lumbar disc herniation (rLDH) is a repeated disc herniation at a previously operated disc level in patients who experienced a pain-free interval of at least 6 months after surgery We investigated whether the preoperative radiologic biomechanical factors (disc height index [DHI] and sagittal range of motion [sROM]) have any effect on rLDH SUMMARY OF BACKGROUND DATA rLDH has been reported in 5% to 15% of patients There have been many studies suggesting various risk factors for rLDH, such as disc degeneration, trauma, age, smoking, gender, and obesity However, these factors did not reflect a biomechanical effect on the affected joint directly Investigation of DHI and sROM would be helpful to understand the biomechanical impact on the occurrence of rLDH METHODS This study enrolled 157 patients who underwent surgery for L4-L5 LDH We divided the patients into the recurrent and the nonrecurrent group and compared their clinical parameters (age, sex, body-mass index, symptom duration, diabetes, smoking, herniation type, preoperative visual analogue scale) and preoperative radiologic parameters (disc degeneration, DHI, sROM) RESULTS rLDH occurred at 408+/-155 months (7-70 months) after primary surgery Mean DHI was 037+/-009 and 029+/-009 in the recurrent and the nonrecurrent group, respectively (P<005) Mean sROM was 113 degrees+/-29 degrees and 59 degrees+/-37 degrees in the recurrent and the nonrecurrent group, respectively (P<005) Both smoking and disc degeneration were related with the development of rLDH (P<005) CONCLUSION Together with our data, DHI and sROM showed a significant correlation with the incidence of recurrent lumbar disc herniation, suggesting that preoperative biomechanical conditions of the spine can be an important pathogenic factor in the site of lumbar disc surgery