Applicability research of round tube CHF mechanistic model in rod bundle channel

Liu, Wei,Peng, Shinian,Shan, Jianqiang,Jiang, Guangming,Liu, Yu,Deng, Jian,Hu, Ying Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.2

In view of the complex geometric structure of the rod bundle channel and the limitation of the current CHF visualization experiment technology, it is very difficult to obtain the rod bundle CHF mechanism directly through the phenomenon of the rod bundle CHF visualization experiment. In order to obtain the applicable CHF mechanism assumption for rod bundle channel, firstly, five most representative DNB type round tube CHF mechanistic models are obtained with evaluation and screening. Then these original round tube CHF mechanistic models based on inlet conditions are converted to local conditions and coupled with subchannel analysis code ATHAS. Based on 5 × 5 full-length rod bundle CHF experimental data independently developed by Nuclear Power Institute of China (NPIC), the applicability research of each model for CHF prediction performance in rod bundle channel is carried out, and the commonness and difference of each model are comparatively studied. The CHF mechanism assumption of superheated liquid layer depletion that is most likely to be applicable for the rod bundle channel is selected and two directions that need to be improved are given. This study provides a reference for the development of CHF mechanistic model in rod bundle channel.

Email Spam Filtering Based on the MNMF Algorithm

Zun-xiong Liu,Shan-shan Tian,Zhi-qiang Huang,Jiang-wei Liu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.1

Content-based email spam filtering is a challenging problem in which emails are often represented as high-dimensional data. This paper proposes an approach to email spam filtering based on max-margin semi-NMF (MNMF). MNMF combines the ideas of semi-NMF and max-margin and performs dimension reduction and classification simultaneously. In MNMF, we employ the same approach as Semi-NMF to update the coefficient matrix (while the other parameters are fixed) instead of quadratic programming. Simulation experiments were performed on two public Chinese email corpuses. The results show that MNMF is much faster and performs much better than support vector machine (SVM) classifiers that use features extracted by principal component analysis or linear discriminant analysis, and the MNMF method also outperforms SVM classification schemes in combination with feature extractions based on NMF and Semi-NMF

Inhibition of cancer cell growth and migration by dihydroxynaphthyl aryl ketones

Wei Xiong,Yun-Feng Li,Shan Liu,Ting Chen,Hong-Tao Zhang,Zhi-Bin Yang,Ying-Ying Ding,De-Pei Gao,Guan-Shun Wang,Jian Dong,Jian Dong 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.4

Dihydroxynaphthyl aryl ketones 1-5 exhibit activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules making them potential anticancer drugs. Therefore, analogues 1-5 have been evaluated for their cytotoxic activity against the cancer cell lines DU-145 (prostate), T24 (bladder) and MCF-7 (breast). notable differences in biological activity were observed for compounds 1-5, most likely related to the nature of the aryl substituent bonded to the carbonyl group. among the tested compounds, only compound 5 showed selectivity for cancer cells over healthy, non-transformed cells. T24 cancer cells treated with compound 5 presented a concentration-dependent decrease in cell proliferation and a loss of migration ability. The cytotoxicity of compounds 1-5 on the selected cell-based assays is discussed in terms of it lipophilicity and polarizability parameters.

Anti-HIV-1 Activity of Lignans from the Fruits of Schisandra rubriflora

Wei-Lie Xiao,Rui-Rui Wang,Wei Zhao,Ren-Rong Tian,Shan-Zhai Shang,Liu-Meng Yang,Jian-Hong Yang,Jian-Xin Pu,Yong-Tang Zheng,Han-Dong Sun 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2-8) . The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1-5 and 7-8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1IIIB induced syncytium formation with EC50 values in the range of 2.26~20.4 μg/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1IIIB inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.

Effects of postharvest chilling and heating treatments on the sensory quality and antioxidant system of daylily flowers

Wei Liu,Juhua Zhang,Qun Zhang,Yang Shan 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.5

Temperature is the most important factor that affects the metabolism of harvested plants. The aim of this study was to investigate the influence and mechanisms of temperature on the antioxidant system in fresh-cut daylily flowers (Hemerocallis lilioasphodelus L.; used for food consumption) during storage. Daylily flowers were harvested and immediately treated by either chilling at 5 °C for 5 days, or by heating with 50 °C hot air for 5 min, then stored at 20 °C for 5 days. The chilling and heating treatments maintained the organoleptic quality and enhanced the antioxidant system of cut daylily flowers. However, different reactions of the antioxidant system were observed under the different temperature treatments. The chilling treatment dramatically enhanced the activities of superoxide dismutase, ascorbate peroxidase, peroxidase, and phenylalanine ammonia lyase, while it decreased the activity of lipoxygenase. Meanwhile, the heating treatment enhanced catalase activity and decreased polyphenol oxidase activity. In addition, the heating treatment reduced the O2− production rate and H2O2 content compared to the control. Changes in membrane permeability, total phenolic content, total flavonoid content, and diphenyl-1-picrylhydrazyl clearance activity showed no significant difference between the chilling and heating treatments, owning to the steady content of phenolic and flavonoid compounds and the delay in the generation of quinones. Thus, our results indicate that cold and heat treatments can impact the preservation of harvested daylilies used for food consumption.

ApCYP4C6 participates in the metabolism of glucosinolates in pea aphids Acyrthosiphon pisum

Liu Lei,Wang Wen-Jun,Song Li-Wen,Wu Yi-Ting,Wei Jiang-Wen,Wang Sen-Shan,Zhou Jing-Jiang 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.1

Cytochrome P450 enzymes play a key role in the metabolism of plant allelochemicals of herbivorous insects. Here, we investigated the role of cytochrome P450 enzyme genes in the metabolism of glucosinolates in the pea aphids. The results showed that compared with the control untreated group, the transcription levels of two cytochrome P450 enzyme genes, ApCYP4C6 and ApCYP4C7, were significantly increased at 24 h and 48 h after glucosinolates treatment. Furthermore, after the aphids were treated with dsCYP4C6 (double stranded CYP4C6) for 48 h, the expression level of ApCYP4C6 in the aphids was significantly decreased, and its mortality was significantly increased by glucosinolates comparing with that of the dsGFP group. The present study demon strated that ApCYP4C6 was involved in the metabolism of glucosinolates by the pea aphids and contributed to further understanding the role of P450 genes in the tolerance of the pea aphids to plant secondary metabolites.

Family of boost and buck‑boost converters with continuous input current and reduced semiconductor count for hybrid energy systems

Shan Miao,Xinyuan Luo,Wei Liu,Yang Jin 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

Power converters are the key link to realize energy transfer from hybrid energy systems (HESs) to loads. In this paper, a family of boost and buck-boost DC-DC converters that is highly desirable for HESs is proposed and analyzed. The proposed converters possess continuous input currents that can realize small input current ripples and avoid the use of large input filters. Besides, the semiconductor counts of the proposed converters are low. Two of the converters employ single-switch doublediode while the other two adopt single-switch triple-diode. The reduced semiconductor counts greatly improve converter efficiency and system reliability. In addition, these boost and buck-boost converters have high voltage-boosting capabilities, and wide voltage gain ranges can be achieved when they are applied to HESs. Theoretical analyses and an experimental prototype are used to verify the characteristics and effectiveness of these converters.

UNUSUAL ELECTROCHEMICAL RESPONSE OF ELECTROCHEMICAL ETCHING ON MULTIWALLED CARBON NANOTUBES

JIAN-SHAN YE,GUANGQUAN MO,WEI DE ZHANG,XIAO LIU,FWU-SHAN SHEU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.6

Multiwalled carbon nanotubes (MWNTs) can be etched at potentials more positive than 1.7 V versus Ag/AgCl (3 M KCl) in 0.2 M HNO3. The electrochemically etched MWNTs show an increase in electrochemical impedance and sluggish electron transfer kinetics, and lose the electrocatalytic effects toward the oxidation of glucose, H2O2, uric acid (UA) and L-ascorbic acid (L-AA). Transmission electron microscope (TEM) images reveal that the nanotube tips are cut off by electrochemical oxidation. This may lead to the degradation of electrocatalytic ability in the MWNTs. Furthermore, the current response after different electrochemically etched cycles shows that the electrocatalytic ability of the MWNTs toward different molecules can be tuned by etched cycles. For example, five etched cycles leads to the total disappearance of the oxidative response to L-AA, with the remaining over 50% of the UA current response in the L-AA and UA mixture. Thus, electrochemical etching is a simple yet novel way to tune the electrocatalytic reactivity and improve the selectivity of the MWNTs.

Parecoxib: an Enhancer of Radiation Therapy for Colorectal Cancer

Xiong, Wei,Li, Wen-Hui,Jiang, Yong-Xin,Liu, Shan,Ai, Yi-Qin,Liu, Rong,Chang, Li,Zhang, Ming,Wang, Xiao-Li,Bai, Han,Wang, Hong,Zheng, Rui,Tan, Jing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: To study the effect of parecoxib, a novel cyclooxygenase-2 selective inhibitor, on the radiation response of colorectal cancer (CRC) cells and its underlying mechanisms. Materials and Methods: Both in vitro colony formation and apoptosis assays as well as in vivo mouse xenograft experiments were used to explore the radiosensitizing effects of parecoxib in human HCT116 and HT29 CRC cells. Results: Parecoxib sensitized CRC cells to radiation in vitro with a sensitivity enhancement ratio of 1.32 for HCT116 cells and 1.15 for HT29 cells at a surviving fraction of 0.37. This effect was partially attributable to enhanced apoptosis induction by parecoxib combined with radiation, as illustrated using an in vitro apoptosis assays. Parecoxib augmented the tumor response of HCT116 xenografts to radiation, achieving growth delay more than 20 days and an enhancement factor of 1.53. In accordance with the in vitro results, parecoxib combined with radiation resulted in less proliferation and more apoptosis in tumors than radiation alone. Radiation monotherapy decreased microvessel density (MVD) and microvessel intensity (MVI), but increased the hypoxia level in xenografts. Parecoxib did not affect MVD, but it increased MVI and attenuated hypoxia. Conclusions: Parecoxib can effectively enhance radiation sensitivity in CRC cells through direct effects on tumor cells and indirect effects on tumor vasculature.

Microarray Analysis of Long Non-coding RNA Expression Profile Associated with 5-Fluorouracil-Based Chemoradiation Resistance in Colorectal Cancer Cells

Xiong, Wei,Jiang, Yong-Xin,Ai, Yi-Qin,Liu, Shan,Wu, Xing-Rao,Cui, Jian-Guo,Qin, Ji-Yong,Liu, Yan,Xia, Yao-Xiong,Ju, Yun-He,He, Wen-Jie,Wang, Yong,Li, Yun-Fen,Hou, Yu,Wang, Li,Li, Wen-Hui Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Preoperative 5-fluorouracil (5-FU)-based chemoradiotherapy is a standard treatment for locally advanced colorectal cancer (CRC). However, CRC cells often develop chemoradiation resistance (CRR). Recent studies have shown that long non-coding RNA (lncRNA) plays critical roles in a myriad of biological processes and human diseases, as well as chemotherapy resistance. Since the roles of lncRNAs in 5-FU-based CRR in human CRC cells remain unknown, they were investigated in this study. Materials and Methods: A 5-FU-based concurrent CRR cell model was established using human CRC cell line HCT116. Microarray expression profiling of lncRNAs and mRNAs was undertaken in parental HCT116 and 5-FU-based CRR cell lines. Results: In total, 2,662 differentially expressed lncRNAs and 2,398 mRNAs were identified in 5-FU-based CRR HCT116 cells when compared with those in parental HCT116. Moreover, 6 lncRNAs and 6 mRNAs found to be differentially expressed were validated by quantitative real time PCR (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for the differentially expressed mRNAs indicated involvement of many, such as Jak-STAT, PI3K-Akt and NF-kappa B signaling pathways. To better understand the molecular basis of 5-FU-based CRR in CRC cells, correlated expression networks were constructed based on 8 intergenic lncRNAs and their nearby coding genes. Conclusions: Changes in lncRNA expression are involved in 5-FU-based CRR in CRC cells. These findings may provide novel insight for the prognosis and prediction of response to therapy in CRC patients.