Flower-like MoS2 Nanospheres: A Promising Material with Good Microwave Absorption Property in the Frequency Range of 8.2–12.4 GHz

XIAOLEI SU,Jing Ning,YAN JIA,Yi Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.7

MoS2 nanospheres have been synthesized by a hydrothermal method at various reaction times using sodium molybdate and thioacetamide as the sulfur source and reducing agent, respectively. The prepared MoS2 nanospheres have been characterized by XRD, SEM and vector network analyzer, respectively. Results show that the prepared MoS2 samples were the flower-like nanospheres and the powder size increased with increasing reaction time. The real part (ε') and imaginary part (ε") of permittivity of the prepared MoS2 nanospheres increased as the reaction time increased initially and decreased afterwards. When the reaction time was 20 h, the ε' and ε" reached the maximum values, 8.25–8.05 and 4.1–3.85, respectively. The minimum reflection loss value of -45 dB was achieved at 8.3 GHz for the synthesized MoS2 nanospheres with reaction time of 16 h. All the samples with matching thicknesses of 2–4mm presented wider effective absorption bandwidths (RL < -10 dB) in the frequency range of 8.2–12.4 GHz.

EFFECT OF REACTION TIME ON MICROSTRUCTURE, DIELECTRIC PROPERTY AND MICROWAVE ABSORPTION PROPERTY OF Cu-DOPED SiC NANOPOWDER

XIAOLEI SU,YONGSHENG TAN,YAN JIA,KAILI ZHAO,SONGTAO LIU,XINHAI HE,CHONG FU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.2

Cu-doped SiC nanopowders have been prepared via combustion synthesis of the silicon andcarbon system in a 0.1 MPa nitrogen atmosphere under di®erent reaction time, using copper asthe dopant and PTFE as the chemical activator, respectively. X-ray di®raction, scanning elec-tronic microscope and Raman spectra have been used to characterize the phase and morphologyof prepared nanopowders. Results indicate that the lattice constant of prepared Cu-doped SiCnanopowder decreases with extending reaction time. The prepared nanopowders have ¯nespherical particles and narrow particle size distribution and the particle size increases withincreasing reaction time. The electric permittivities of prepared Cu-doped SiC nanopowders inthe frequency range of 8.2 – 12.4 GHz have been determined. The real part " 0, imaginary part " 00and dielectric loss tg ? of complex permittivity decrease with increasing reaction time. All pre-pared Cu-doped SiC nanopowder exhibits good microwave absorption property in the frequencyrange of 8.2 – 12.4 GHz.

Dependence assessment in human reliability analysis under uncertain and dynamic situations

Xianghao Gao,Xiaoyan Su,Hong Qian,Xiaolei Pan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

Since reliability and security of man-machine system increasingly depend on reliability of human, humanreliability analysis (HRA) has attracted a lot of attention in many fields especially in nuclear engineering. Dependence assessment among human tasks is a important part in HRA which contributes to anappropriate evaluation result. Most of methods in HRA are based on experts’ opinions which are subjectiveand uncertain. Also, the dependence influencing factors are usually considered to be constant,which is unrealistic. In this paper, a new model based on DempstereShafer evidence theory (DSET) andfuzzy number is proposed to handle the dependence between two tasks in HRA under uncertain anddynamic situations. First, the dependence influencing factors are identified and the judgments on thefactors are represented as basic belief assignments (BBAs). Second, the BBAs of the factors that varyingwith time are reconstructed based on the correction BBA derived from time value. Then, BBAs of allfactors are combined to gain the fused BBA. Finally, conditional human error probability (CHEP) isderived based on the fused BBA. The proposed method can deal with uncertainties in the judgments anddynamics of the dependence influencing factors. A case study is illustrated to show the effectiveness andthe flexibility of the proposed method.

Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

Jiang Liu,Rong Xu,Xiaolei He,Reyina Wufuli,Ying Su,Lili Ma,Ru Chen,Zhongcheng Han,Fang Wang 대한위암학회 2019 Journal of gastric cancer Vol.19 No.4

Purpose: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer. Materials and Methods: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed. Results: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739–1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481–1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179–0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019–4.837; P=0.049). Conclusions: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

Xu, Rong,He, Xiaolei,Wufuli, Reyina,Su, Ying,Ma, Lili,Chen, Ru,Han, Zhongcheng,Wang, Fang,Liu, Jiang The Korean Gastric Cancer Association 2019 Journal of gastric cancer Vol.19 No.4

Purpose: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer. Materials and Methods: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed. Results: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739-1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481-1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179-0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019-4.837; P=0.049). Conclusions: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

Degradation characteristic of TiO_2-chitosan adsorbent on Rhodamine B and purification of industrial wastewater

Xin Zhang,Haijia Su,Xiaolei Zhao 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.5

Based on biosorption and photodegradation coupling technology, a novel adsorbent, which not only adsorbs the heavy metal ions but also degrades organic compound, was prepared by immobilization of nano-TiO_2 on chitosan matrix. Degradation characteristic of Rhodamine B (Rh.B) was investigated by TiO_2-chitosan adsorbents. The results showed that degradation ratio reached 94.3% by 0.2 g adsorbents under ultraviolet radiation light (UV) at initial Rh.B concentration of 10 mg/L and optimal pH of 9.0. Degradation and adsorption behavior characteristics were discussed in the presence of binary pollutants (Rh.B and Ag^+). The coexistence of Ag+ intensely inhibited the degradation ability of Rh.B. Higher Ag^+ concentration weakened the degradation ability. However, Rh.B did not affect the adsorption capacity of Ag^+. Moreover, TiO_2-chitosan adsorbent contributed to a higher degradation ability of organic pollutants in practical wastewater. Degradation capacity of contaminants in paper-making wastewater reached 60.8 mg/g at the initial COD concentration of 2,000 mg/L.

Handling dependencies among performance shaping factors in SPAR-H through DEMATEL method

Xu Zhihui,Shang Shuwen,Su Xiaoyan,Qian Hong,Pan Xiaolei 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.8

The Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method is a widely used method in human reliability analysis (HRA). Performance shaping factors (PSFs) refer to the factors that may influence human performance and are used to adjust nominal human error probabilities (HEPs) in SPAR-H. However, the PSFs are assumed to be independent, which is unrealistic and can lead to unreasonable estimation of HEPs. In this paper, a new method is proposed to handle the dependencies among PSFs in SPAR-H to obtain more reasonable results. Firstly, the dependencies among PSFs are analyzed by using decision-making trial and evaluation laboratory (DEMATEL) method. Then, PSFs are assigned different weights according to their dependent relationships. Finally, multipliers of PSFs are modified based on the relative weights of PSFs. A case study is illustrated that the proposed method is effective in handling the dependent PSFs in SPAR-H, where the duplicate calculations of the dependent part can be reduced. The proposed method can deal with a more general situation that PSFs are dependent, and can provide more reasonable results.

Major ginsenosides from Panax ginseng promote aerobic cellular respiration and SIRT1-mediated mitochondrial biosynthesis in cardiomyocytes and neurons

Huang, Qingxia,Lou, Tingting,Lu, Jing,Wang, Manying,Chen, Xuenan,Xue, Linyuan,Tang, Xiaolei,Qi, Wenxiu,Zhang, Zepeng,Su, Hang,Jin, Wenqi,Jing, Chenxu,Zhao, Daqing,Sun, Liwei,Li, Xiangyan The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

Background: Aerobic cellular respiration provides chemical energy, adenosine triphosphate (ATP), to maintain multiple cellular functions. Sirtuin 1 (SIRT1) can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) to promote mitochondrial biosynthesis. Targeting energy metabolism is a potential strategy for the prevention and treatment of various diseases, such as cardiac and neurological disorders. Ginsenosides, one of the major bioactive constituents of Panax ginseng, have been extensively used due to their diverse beneficial effects on healthy subjects and patients with different diseases. However, the underlying molecular mechanisms of total ginsenosides (GS) on energy metabolism remain unclear. Methods: In this study, oxygen consumption rate, ATP production, mitochondrial biosynthesis, glucose metabolism, and SIRT1-PGC-1α pathways in untreated and GS-treated different cells, fly, and mouse models were investigated. Results: GS pretreatment enhanced mitochondrial respiration capacity and ATP production in aerobic respiration-dominated cardiomyocytes and neurons, and promoted tricarboxylic acid metabolism in cardiomyocytes. Moreover, GS clearly enhanced NAD⁺-dependent SIRT1 activation to increase mitochondrial biosynthesis in cardiomyocytes and neurons, which was completely abrogated by nicotinamide. Importantly, ginsenoside monomers, such as Rg1, Re, Rf, Rb1, Rc, Rh1, Rb2, and Rb3, were found to activate SIRT1 and promote energy metabolism. Conclusion: This study may provide new insights into the extensive application of ginseng for cardiac and neurological protection in healthy subjects and patients.