The beneficial effect of ginsenosides extracted by pulsed electric field against hydrogen peroxide-induced oxidative stress in HEK-293 cells

Di Liu,Ting Zhang,Zhifei Chen,Ying Wang,Shuang Ma,Jiyun Liu,Jingbo Liu 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.2

Background: Ginsenosides are the main pharmacological components of Panax ginseng root, which are thought to be primarily responsible for the suppressing effect on oxidative stress. Methods: 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorption capacity were applied to evaluate the antioxidant activities of the ginsenosides. Human embryonic kidney 293 (HEK-293) cells were incubated with ginsenosides extracted by pulsed electric field (PEF) and solvent cold soak extraction (SCSE) for 24 h and then the injury was induced by 40mM H2O2. The cell viability and surface morphology of HEK-293 cells were studied using MTS assay and scanning electron microscopy, respectively. Dichloro-dihydro-fluorescein diacetate fluorescent probe assay was used to measure the level of intracellular reactive oxygen species. The intracellular antioxidant activities of ginsenosides were evaluated by cellular antioxidant activity assay in HepG2 cells. Results: The PEF extracts displayed the higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and stronger oxygen radical absorption capacity (with an oxygen radical absorption capacity value of 14.48 4.04mM TE per mg/mL). The HEK-293 cell model also suggested that the protective effect of PEF extracts was dose-dependently greater than SCSE extracts. Dichloro-dihydro-fluorescein diacetate assay further proved that PEF extracts are more active (8% higher than SCSE extracts) in reducing intracellular reactive oxygen species accumulation. In addition, scanning electron microscopy images showed that the HEK-293 cells, which were treated with PEF extracts, maintained more intact surface morphology. Cellular antioxidant activity values indicated that ginsenosides extracted by PEF had stronger cellular antioxidant activity than SCSE ginsenosides extracts. Conclusion: The present study demonstrated the antioxidative effect of ginsenosides extracted by PEF in vitro. Furthermore, rather than SCSE, PEF may be more useful as an alternative extraction technique for the extraction of ginsenosides with enhanced antioxidant activity.

The beneficial effect of ginsenosides extracted by pulsed electric field against hydrogen peroxide-induced oxidative stress in HEK-293 cells

Liu, Di,Zhang, Ting,Chen, Zhifei,Wang, Ying,Ma, Shuang,Liu, Jiyun,Liu, Jingbo The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.2

Background: Ginsenosides are the main pharmacological components of Panax ginseng root, which are thought to be primarily responsible for the suppressing effect on oxidative stress. Methods: 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorption capacity were applied to evaluate the antioxidant activities of the ginsenosides. Human embryonic kidney 293 (HEK-293) cells were incubated with ginsenosides extracted by pulsed electric field (PEF) and solvent cold soak extraction (SCSE) for 24 h and then the injury was induced by $40{\mu}M$ $H_2O_2$. The cell viability and surface morphology of HEK-293 cells were studied using MTS assay and scanning electron microscopy, respectively. Dichloro-dihydro-fluorescein diacetate fluorescent probe assay was used to measure the level of intracellular reactive oxygen species. The intracellular antioxidant activities of ginsenosides were evaluated by cellular antioxidant activity assay in HepG2 cells. Results: The PEF extracts displayed the higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and stronger oxygen radical absorption capacity (with an oxygen radical absorption capacity value of $14.48{\pm}4.04{\mu}M\;TE\;per\;{\mu}g/mL$). The HEK-293 cell model also suggested that the protective effect of PEF extracts was dose-dependently greater than SCSE extracts. Dichloro-dihydro-fluorescein diacetate assay further proved that PEF extracts are more active (8% higher than SCSE extracts) in reducing intracellular reactive oxygen species accumulation. In addition, scanning electron microscopy images showed that the HEK-293 cells, which were treated with PEF extracts, maintained more intact surface morphology. Cellular antioxidant activity values indicated that ginsenosides extracted by PEF had stronger cellular antioxidant activity than SCSE ginsenosides extracts. Conclusion: The present study demonstrated the antioxidative effect of ginsenosides extracted by PEF in vitro. Furthermore, rather than SCSE, PEF may be more useful as an alternative extraction technique for the extraction of ginsenosides with enhanced antioxidant activity.

Visualizing the National Security Information Science Knowledge Network in China

Liu Di,Hua Minchao 아시아사회과학학회 2020 Jornal of Asia Social Science Vol.1 No.3

In order to better understand the development process and role of national security information in the field of national security research, this paper analyzes the scientific atlas of national security information from the perspective of overall national security concept, and concludes that the disciplines involved in studying national security issues under overall national security concept include ideological and political theory courses, national security science, security management, national security information science, etc., It points out that the continuous integration of related disciplines promotes the emergence of national security information science as a separate discipline, and points out the research trend of national security information under overall national security concept.

Elucidating Bottlenecks to the Efficient Preparation of AB₅-Hexamer Mucosal Adjuvant Protein LTm by Genetic Engineering

( Di Liu ),( Fabiao Hu ),( Wenpeng Wang ),( Dong Wu ),( Xiujuan He ),( Wenyun Zheng ),( Haipeng Liu ),( Xingyuan Ma ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.8

Escherichia coli heat-labile enterotoxin (LT) and its non-toxic mutant (LTm) are well-known powerful mucosal adjuvants and immunogens. However, the yields of these adjuvants from genetically engineered strains remain at extremely low levels, thereby hindering their extensive application in fundamental and clinical research. Therefore, efficient production of these adjuvant proteins from genetically engineered microbes is a huge challenge in the field of molecular biology. In order to explore the expression bottlenecks of LTm in E. coli, we constructed a series of recombinant plasmids based on various considerations and gene expression strategies. After comparing the protein expression among strains containing different recombinant plasmids, the signal sequence was found to be critical for the expression of LTm and its subunits. When the signal sequence was present, the strong hydrophobicity and instability of this amino acid sequence greatly restricted the generation of subunits. However, when the signal sequence was removed, abundantly expressed subunits formed inactive inclusion bodies that could not be assembled into the hexameric native form, although the inclusion body subunits could be refolded and the biological activity recovered in vitro. Therefore, the dilemma choice of signal sequence formed bottlenecks in the expression of LTm. These results reveal the expression bottlenecks of LTm, provide guidance for the preparation of LTm and its subunits, and certainly help to promote efficient preparation of this mucosal adjuvant protein.

Hierarchical hollow urchin-like structured MnO2 microsphere/carbon nanofiber composites as anode materials for Li-ion batteries

Di Liu,최원묵 한국물리학회 2019 Current Applied Physics Vol.19 No.6

In this work, novel hollow urchin-like MnO2 microspheres (u-MnO2), consisting of a hollow core with nanotubes, are synthesized by a simple hydrothermal process. The morphology of the MnO2 structures could be tuned from round particles to a hierarchical hollow urchin structure by controlling the hydrothermal reaction time, with no need for surfactant or templates. The nanostructures of the obtained u-MnO2 are characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The X-ray diffraction (XRD) pattern of the u-MnO2 reveals a tetragonal structure of α-MnO2. The carbon nanofibers (CNFs) are uniformly deposited on u-MnO2 to improve the electrical conductivity and to utilize the hierarchical architecture of u-MnO2. As the anode electrode of Li-ion batteries, the u-MnO2/CNFs nanocomposites exhibit discharge capacity of 988 mAh·g−1 after 100 cycles with a good rate capability. The superior electrochemical performances of the u- MnO2/CNFs nanocomposites can be attributed to the hierarchical urchin-like structures and the superior electrical conductivity of the nanocomposites, which can facilitate fast electron and ion transport and accommodate a large volume change during charge/discharge.

RB1 Polymorphism Contributes to the Efficacy of Platinum-Taxanes in Advanced Squamous Cell Lung Cancer

Liu, Di,Xu, Wen,Zhang, Zhi-Wei,Qian, Ji,Zheng, Hui,Zhang, Jie,Su, Bo Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: RB1 (retinoblastoma 1) was reportedly one of the major determinative factors for sensitivity to taxanes in previous studies. In this study, we investigated the influence of RB1 single nucleotide polymorphisms (SNPs) on the efficacy of platinum-taxane regimens in advanced NSCLC patients. Materials and Methods: 234 cases of patients with advanced NSCLC who were treated with first-line platinum-taxane agents were enrolled in this study. Genomic DNA was extracted from patients' peripheral blood samples using a QIAamp DNA Maxi Kit, and genotyped by iSelect HD Bead-Chip. Results: Regression analyses were conducted through the univariate and multivariate Cox proportional hazards model in the 234 patients. The results showed that of the eight RB1 tagSNPs, only rs4151510 was a positive predictive factor for the advanced NSCLC patients treated with platinum taxanes regimen. The patients with G/G genotype of RB rs4151510 had longer overall survival (OS) than the non-G/G genotype (p=0.018). The histology was also correlated with OS in the whole advanced NSCLC patients. Three tagSNPs of RB1, rs4151510, rs4151465, rs9568036 were significantly associated with OS in the advanced NSCLC patients with squamous cell histology using Kaplan-Meier overall survival analysis stratified by histology. Conclusions: RB1 genomic variants were correlated with the efficacy of platinum-taxanes regimen. RB rs4151510 is an independent factor of the prognosis of NSCLC patients receiving platinum-taxane chemotherapy.

FOLLOW-UP OBSERVATIONS TOWARD PLANCK COLD CLUMPS WITH GROUND-BASED RADIO TELESCOPES

LIU, TIE,WU, YUEFANG,MARDONES, DIEGO,KIM, KEE-TAE,MENTEN, KARL M.,TATEMATSU, KEN,CUNNINGHAM, MARIA,JUVELA, MIKA,ZHANG, QIZHOU,GOLDSMITH, PAUL F,LIU, SHENG-YUAN,ZHANG, HUA-WEI,MENG, FANYI,LI, DI,LO, NA The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature (< 14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from a mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.

Mechanical Response of Barricade to Coupled THMC Behavior of Cemented Paste Backfill

Di Wu,Wentao Hou,Shuai Liu,Huaibin Liu 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

Cemented paste backfill (CPB), which is prepared by mixing tailings, binder and water, is widely used in underground mines for waste management and ground control. Since the CPB is delivered into mined-out areas in the form of fluid, a barricade needs to be constructed for retaining it during the process of its filling and hardening. Therefore, the barricade should have enough mechanical stability to ensure the safety of the backfill operation. The behavior of CPB, which is influenced by the thermal, hydraulic, mechanical and chemical (THMC) coupled processes, acts on the barricade and thus affects its mechanical response. In the present study, a numerical model is developed to predict and analyze the barricade mechanical performance in response to the coupled THMC behavior of CPB. The validity of the proposed model is then verified against two field case studies. Acceptable agreement between the model prediction results and in situ monitoring data proves the capability of the developed model in simulating the barricade pressure and displacement. Then, the validated model is used to investigate the effect of filling strategy on the barricade displacement. The obtained results can contribute to a better understanding of the barricade performance under various backfill conditions.

한국과 중국의 실시간 참여 예능 프로그램 비교

Liu Mu Di 한국문화예술경영학회 2019 문화예술경영학연구 Vol.12 No.1

사람들은 일방적인 전파방식에 만족하지 않고 이미 내려진 결론을 수동적으로 받아들이기를 꺼려한다. 사람들의증가하는 요구 중 하나는 전파에 직접 참여하는 것이고 자신의 의견과 생각을 전파 중에 발표하는 것이다. 이런 표현의 욕구는 TV 프로그램에서 시청자들의 참여의식으로 나타났다. 시청자의 강한 참여의식 요구는 직접적인 프로그램의 방송과정에 참여하는 것이다. 이로 인해 TV 프로그램의 일방적 전파방식은 양방향 전파방식으로 바뀌었다. 예능 프로그램 제작팀도 시청자들의 참여의식이 강해지는 것을 의식하기 시작하여 시청자 참여기회를 확대하고있다. 예능 프로그램은 시청자의 요구에 맞춰 다양한 참여 방식을 제공하고, 참여하려는 시청자들의 욕구를 자극하며참여 열기를 높이고 있다. 시청자들의 참여는 예능 프로그램의 발전을 촉진시키고, 시청률을 높이며, 예능 프로그램의 이익을 증가시킨다. 본 논문은 시청자의 실시간 참여를 중점적으로 연구한다. 한중 양국의 비교를 통해 양국 예능프로그램의 시청자가 실시간으로 참여하는 사례를 살펴본다. 예능 프로그램 시청자가 실시간으로 프로그램에 참여하는 과정과 그에 따른 효과를 알아보고자 한다.

Gap junction blockage promotes cadmium-induced apoptosis in BRL 3A derived from Buffalo rat liver cells

Di Hu,Hui Zou,Tao Han,Junze Xie,Nannan Dai,Liling Zhuo,Jianhong Gu,Jianchun Bian,Yan Yuan,Xuezhong Liu,Zongping Liu 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

Gap junctions mediate direct communication between cells; however, toxicological cascade triggered by nonessential metals can abrogate cellular signaling mediated by gap junctions. Although cadmium (Cd) is known to induce apoptosis in organs and tissues, the mechanisms that underlie gap junction activity in Cd-induced apoptosis in BRL 3A rat liver cells has yet to be established. In the present study, we showed that Cd treatment decreased the cell index (a measure of cellular electrical impedance) in BRL 3A cells. Mechanistically, we found that Cd exposure decreased expression of connexin 43 (Cx43), increased expression of p-Cx43 and elevated intracellular free Ca2+ concentration, corresponding to a decrease in gap junctional intercellular communication. Gap junction blockage pretreatment with 18b-glycyrrhizic acid (GA) promoted Cd-induced apoptosis, involving changes in expression of Bax, Bcl-2, caspase-3 and the mitochondrial transmembrane electrical potential (Δym). Additionally, GA was found to enhance ERK and p38 activation during Cd-induced activation of mitogen-activated protein kinases, but had no significant effect on JNK activation. Our results indicated the apoptosis-related proteins and the ERK and p38 signaling pathways may participate in gap junction blockage promoting Cd-induced apoptosis in BRL 3A cells.