Practical Calculation Method for the Short‑Circuit Current of Power Grids with High Temperature Superconducting Fault Current Limiters

Hai‑feng Hong,Meng‑ze Yu,Xiao‑hui Zhang,Jia‑jia Huan,Yu Sui,Xian‑xian Pan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2

With the expansion of the power grid scale and the enhancement of network structure interconnection, the short-circuit current of power grids is increasingly close to the upper capacity limit of circuit breakers. The fault current limiter is efective in suppressing the short-circuit current of power grids, and with the mature development of superconducting technology, high-temperature superconducting fault current limiters (HTS-FCLs) have been widely used in power grids. Due to the nonlinear impedance–current characteristic of HTS-FCLs, the traditional short-circuit current calculation method is inapplicable to power grids with HTS-FCLs. First, based on the establishment of the electromechanical transient model and the short-circuit calculation model, the short-circuit current calculation procedure for power grids with HTS-FCLs is proposed. Second, the calculation methods for three-phase and single-phase short-circuit currents at the substation bus in power grids with HTS-FCLs are analyzed. Finally, three-phase and single-phase short-circuit currents at the 500 kV Xijiang substation bus in the Guangdong power grid are calculated as the study case. Simulation results show that compared with the situation where there is no HTS-FCL installed, the short-circuit current on the 500 kV bus decreases from 65.34 to 58.31 kA in terms of the three-phase short-circuit fault, and decreases from 54.56 to 46.62 kA in terms of the single-phase short-circuit fault, thus verifying the efectiveness and practicability of HTS-FCLs in suppressing the short-circuit current, which is signifcant for the safe, stable and reliable operation of the power grid.

Protective efficacy of a high-growth reassortant swine H3N2 inactivated vaccine constructed by reverse genetic manipulation

Feng Wen,Ji-Hong Ma,Hai Yu,Fu-Ru Yang,Meng Huang,Yan-Jun Zhou,Ze-Jun Li,Guangzhi Tong 대한수의학회 2014 JOURNAL OF VETERINARY SCIENCE Vol.15 No.3

Novel reassortant H3N2 swine influenza viruses (SwIV)with the matrix gene from the 2009 H1N1 pandemic virushave been isolated in many countries as well as duringoutbreaks in multiple states in the United States, indicatingthat H3N2 SwIV might be a potential threat to public health. Since southern China is the world’s largest producer of pigs,efficient vaccines should be developed to prevent pigs fromacquiring H3N2 subtype SwIV infections, and thus limit thepossibility of SwIV infection at agricultural fairs. In thisstudy, a high-growth reassortant virus (GD/PR8) wasgenerated by plasmid-based reverse genetics and tested as acandidate inactivated vaccine. The protective efficacy of thisvaccine was evaluated in mice by challenging them withanother H3N2 SwIV isolate [A/Swine/Heilongjiang/1/05(H3N2) (HLJ/05)]. Prime and booster inoculation withGD/PR8 vaccine yielded high-titer serum hemagglutinationinhibiting antibodies and IgG antibodies. Completeprotection of mice against H3N2 SwIV was observed, withsignificantly reduced lung lesion and viral loads invaccine-inoculated mice relative to mock-vaccinatedcontrols. These results suggest that the GD/PR8 vaccine mayserve as a promising candidate for rapid intervention ofH3N2 SwIV outbreaks in China.

Investigation of Microstructural Evolution and Electrical Properties for Ni-Sn Transient Liquid-Phase Sintering Bonding

Hong-Liang Feng,Ji-Hua Huang,Jian Yang,Shao-Kun Zhou,Rong Zhang,Yue Wang,Shu-Hai Chen 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.6

Ni/Ni-Sn/Ni sandwiched simulated package structures weresuccessfully bonded under low temperature and low pressure byNi-Sn transient liquid-phase sintering bonding. The results showthat, after isothermally holding for 240 min at 300 °C and 180 minat 340 °C, Sn was completely transformed into Ni3Sn4 intermetalliccompounds. When the Ni3Sn4 phases around Ni particles werepressed together, the porosity of the bonding layer increased, whichobviously differed from the normal sintering densification process. With further analysis of this phenomenon, it was found that largevolume shrinkage (14.94% at 340 °C) occurred when Ni reactedwith Sn to form Ni3Sn4, which caused void formation. Amechanistic model of the microstructural evolution in the bondinglayer was proposed. Meanwhile, the resistivity of the bonding layerwas measured and analyzed by using the four-probe method; themicrostructural evolution was well reflected by the resistivity ofthe bonding layer. The relationship between the resistivity andmicrostructure was also discussed in detail.

Enhancing mucosal immunity in mice by recombinant adenovirus expressing major epitopes of porcine circovirus-2 capsid protein delivered with cytosine-phosphate-guanosine oligodeoxynucleotides

Hong-tao Chang,Xiu-yuan He,Yu-Feng Liu,Lu Chen,Quan-hai Guo,Qiu-ying Yu,Jun Zhao,Xin-wei Wang,Xia Yang,Chuan-qing Wang 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.3

A recombinant replication-defective adenovirus expressingthe major epitopes of porcine circovirus-2 (PCV-2) capsidprotein (rAd/Cap/518) was previously constructed and shownto induce mucosal immunity in mice following intranasaldelivery. In the present study, immune responses induced byintranasal immunization with a combination of rAd/Cap/518and cytosine-phosphate-guanosine oligodeoxynucleotides(CpG ODN) were evaluated in mice. The levels ofPCV-2-specific IgG in serum and IgA in saliva, lung, andintestinal fluids were significantly higher in the groupimmunized with rAd/Cap/518 and CpG ODN than animalsimmunized with rAd/Cap/518 alone. The frequencies ofIL-2-secreting CD4+ T cells and IFN-γ-producing CD8+ T cellswere significantly higher in the combined immunizationgroup than mice immunized with rAd/Cap/518 alone. Thefrequencies of CD3+, CD3+CD4+CD8−, and CD3+CD4−CD8+T cells in the combined immunization group were similar tothat treated with CpG ODN alone, but significantly higherthan mice that did not receive CpG ODN. PCV-2 load afterchallenge in the combined immunization group wassignificantly lower than that in the phosphate-buffered salineplacebo group and approximately 7-fold lower in the grouptreated with CpG ODN alone. These results indicate thatrAd/Cap/518 combined with CpG ODN can enhance systemicand local mucosal immunity in mice, and represent apromising synergetic mucosal vaccine against PCV-2.

IQGAP1 is overexpressed in hepatocellular carcinoma and promotes cell proliferation by Akt activation

Feng Chen,Zhi Chen,Hai-Hong Zhu,Lin-Fu Zhou,Shan-Shan Wu,Jing Wang 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.7

The scaffold protein IQGAP1 shows elevated levels in several cancer types, but its expression in hepatocellular carcinoma is unknown. We found that 58%of human hepatocellular carcinoma tissue samples had increased IQGAP1 expression compared to adjacent normal tissue. Overexpressing IQGAP1 raised the in vivo tumorigenicity of hepatocellular carcinoma cells, and forced overexpression of IQGAP1 in vitro stimulated cell proliferation. Cell growth was reduced by knockdown or mutation of IQGAP1, or by treatment of cells with a phosphotidylinositol 3-kinase inhibitor. To determine the mechanism by which IQGAP1 overexpression affected hepatocellular carcinoma cells,we confirmed its interaction in these cells with mammalian target of rapamycin (mTOR), a serine/threonine kinase that integrates signals about nutrient and energy status with downstream effectors that influence cell division. In addition, we discovered a new interaction involving IQGAP1, mTOR and Akt, which is a downstream target of mTOR. Akt phosphorylation on Ser-473, which is catalyzed by mTOR and required for Akt activation, increased with increasing amounts of IQGAP1, and decreased with IQGAP1 mutation. We hypothesize that IQGAP1 is a scaffold that facilitates mTOR and Akt interaction.

Multiple Impairments in Male Reproduction 1 (mimr1), a Novel Male-Sterile Mutant of Arabidopsis thaliana, Shows Several Defects in Male Reproductive Development

Hai-Yan Chen,Yue-Feng Guan,Xue-Yong Huang,Yu-Ting Wu,Fen-Fei Wang,Ju-Fang Gao,Que Zhou,Zhong-Nan Yang,Jia-Yao Liu,Hong-Xia Zhang 한국식물학회 2012 Journal of Plant Biology Vol.55 No.3

We have characterized a new male-sterile mutant in Arabidopsis that exhibits conditional sterility but has restored fertility when drought-stressed. This mutant,multiple impairments in male reproduction 1 (mimr1),shows pleiotropic defects in both vegetative and reproductive development. Examination with dissecting and scanning electron microscopes revealed that its pollen grains are not effectively released from the anther locule after dehiscence, and anther differentiation is defective. Growth of the style and stamen filaments are also abnormal. Histological analysis demonstrated that these phenomena are due not only to a noticeably reduced extension of the stamen but also greater elongation of the pistil. Genetic analysis indicated that mimr1 is a single locus recessive nuclear mutant. The mutation can be mapped to a locus strongly linked to a 1200-kb region on Chromosome 3. Meta-analysis of expression patterning presented several candidate genes in that region. No mutants with similar phenotypes have previously been reported, suggesting that mimr1 is a novel male-sterile locus. Characterization of MIMR1 will provide further insights into the molecular basis for the development of plant reproductive organs.

A novel M2e-multiple antigenic peptide providing heterologous protection in mice

Feng Wen,Ji-Hong Ma,Hai Yu,Fu-Ru Yang,Meng Huang,Yan-Jun Zhou,Ze-Jun Li,Xiu-Hui Wang,Guo-Xin Li,Yi-Feng Jiang,Wu Tong,Guangzhi Tong 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

Swine influenza viruses (SwIVs) cause considerable morbidity and mortality in domestic pigs, resulting in a significant economic burden. Moreover, pigs have been considered to be a possible mixing vessel in which novel strains loom. Here, we developed and evaluated a novel M2e-multiple antigenic peptide (M2e-MAP) as a supplemental antigen for inactivated H3N2 vaccine to provide cross-protection against two main subtypes of SwIVs, H1N1 and H3N2. The novel tetra-branched MAP was constructed by fusing four copies of M2e to one copy of foreign T helper cell epitopes. A high-yield reassortant H3N2 virus was generated by plasmid based reverse genetics. The efficacy of the novel H3N2 inactivated vaccines with or without M2e-MAP supplementation was evaluated in a mouse model. M2e-MAP conjugated vaccine induced strong antibody responses in mice. Complete protection against the heterologous swine H1N1 virus was observed in mice vaccinated with M2e-MAP combined vaccine. Moreover, this novel peptide confers protection against lethal challenge of A/Puerto Rico/8/34 (H1N1). Taken together, our results suggest the combined immunization of reassortant inactivated H3N2 vaccine and the novel M2e-MAP provided cross-protection against swine and human viruses and may serve as a promising approach for influenza vaccine development.

Ginsenoside Rg5 overcomes chemotherapeutic multidrug resistance mediated by ABCB1 transporter: in vitro and in vivo study

Feng, Sen-Ling,Luo, Hai-Bin,Cai, Liang,Zhang, Jie,Wang, Dan,Chen, Ying-Jiang,Zhan, Huan-Xing,Jiang, Zhi-Hong,Xie, Ying The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.2

Background: Multidrug resistance (MDR) to chemotherapy drugs remains a major challenge in clinical cancer treatment. Here we investigated whether and how ginsenoside Rg5 overcomes the MDR mediated by ABCB1 transporter in vitro and in vivo. Methods: Cytotoxicity and colon formation as well as the intracellular accumulation of ABCB1 substrates were carried out in MDR cancer cells A2780/T and A549/T for evaluating the reversal effects of Rg5. The expressions of ABCB1 and Nrf2/AKT pathway were determined by Western blotting. An A549/T cell xenograft model was established to investigate the MDR reversal activity of Rg5 in vivo. Results: Rg5 significantly reversed ABCB1-mediated MDR by increasing the intracellular accumulation of ABCB1 substrates without altering protein expression of ABCB1. Moreover, Rg5 activated ABCB1 ATPase and reduced verapamil-stimulated ATPase activity, suggesting a high affinity of Rg5 to ABCB1 binding site which was further demonstrated by molecular docking analysis. In addition, co-treatment of Rg5 and docetaxel (TXT) suppressed the expression of Nrf2 and phosphorylation of AKT, indicating that sensitizing effect of Rg5 associated with AKT/Nrf2 pathway. In nude mice bearing A549/T tumor, Rg5 and TXT treatment significantly suppressed the growth of drug-resistant tumors without increase in toxicity when compared to TXT given alone at same dose. Conclusion: Therefore, combination therapy of Rg5 and chemotherapy drugs is a strategy for the adjuvant chemotherapy, which encourages further pharmacokinetic and clinical studies.

Effects of Age, Breast Density and Volume on Breast Cancer Diagnosis: A Retrospective Comparison of Sensitivity of Mammography and Ultrasonography in China's Rural Areas

Wang, Feng-Liang,Chen, Fei,Yin, Hong,Xu, Nan,Wu, Xiao-Xiang,Ma, Jing-Jing,Gao, Shen,Tang, Jin-Hai,Lu, Cheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Purpose: Mammography has been confirmed as the only effective mode to improve the prognosis of patients with breast cancer in Western developed countries, but might not be a good choice in other areas of the world. One of the major challenges in China is to determine an optimal imaging modality for breast cancer screening. This study was designed to clarify the sensitivity of ultrasonography compared with that of mammography in rural China. Methods: We retrospectively studied the sensitivity of mammography and ultrasonography based on 306 breast cancer patients detected by the program of "screening for cervical cancer and breast cancer" performed in Chinese rural areas between January 2009 and December 2011, and analyzed the effects of age, breast density and volume on the sensitivity. Results: Stratified analysis showed that the sensitivity of breast ultrasonography was significantly higher than that of mammography in premenopausal patients (81.4% vs. 61.1%, p=0.02), in women ${\leq}$ 55 years of age (82.2% vs. 63.4%, p<0.01), in the high breast density group (American College of Radiology [ACR] levels 3-4) (85.9% vs. 60.6%, p<0.01) and in the small breast volume group (${\leq}$ 400 ml) (87.1% vs. 66.7%, p<0.01). Age had a significant effect on sensitivity of mammography (breast density and volume-adjusted odds ratio, 6.39; 95% confidence interval, 2.8-14.4 in age group > 55 compared to age group ${\leq}$ 45), but not that of ultrasonography. Neither breast density nor volume had significant effect on sensitivity of mammography or ultrasonography. Conclusions: Ultrasonography is more sensitive than mammography in detecting breast cancer in women under 55 year-old Chinese, especially in those with high-density and relatively small breasts.

IQGAP1 is overexpressed in hepatocellular carcinoma and promotes cell proliferation by Akt activation

Chen, Feng,Zhu, Hai-Hong,Zhou, Lin-Fu,Wu, Shan-Shan,Wang, Jing,Chen, Zhi Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.7

The scaffold protein IQGAP1 shows elevated levels in several cancer types, but its expression in hepatocellular carcinoma is unknown. We found that 58% of human hepatocellular carcinoma tissue samples had increased IQGAP1 expression compared to adjacent normal tissue. Overexpressing IQGAP1 raised the in vivo tumorigenicity of hepatocellular carcinoma cells, and forced overexpression of IQGAP1 in vitro stimulated cell proliferation. Cell growth was reduced by knockdown or mutation of IQGAP1, or by treatment of cells with a phosphotidylinositol 3-kinase inhibitor. To determine the mechanism by which IQGAP1 overexpression affected hepatocellular carcinoma cells, we confirmed its interaction in these cells with mammalian target of rapamycin (mTOR), a serine/threonine kinase that integrates signals about nutrient and energy status with downstream effectors that influence cell division. In addition, we discovered a new interaction involving IQGAP1, mTOR and Akt, which is a downstream target of mTOR. Akt phosphorylation on Ser-473, which is catalyzed by mTOR and required for Akt activation, increased with increasing amounts of IQGAP1, and decreased with IQGAP1 mutation. We hypothesize that IQGAP1 is a scaffold that facilitates mTOR and Akt interaction.