An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Yu-Zhang Lin,Li-Bao Shi,Liang-Zhong Yao,Yi-Xin Ni,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

Chemokine Signaling Pathway Involved in CCL2 Expression in Patients with Rheumatoid Arthritis

Lin Zhang,Changyi Li,Min Yu,Jiayin Deng,Xing Lv,Jun Liu,Yu Xiao,Wenjie Yang,Yuru Zhang 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.4

Purpose: Rheumatoid arthritis (RA) is an inflammatory joint disorder, the progressionof which leads to the destruction of cartilage and bone. Chemokines are involvedin RA pathogenesis. In this study, we investigated the chemokine signaling pathway associated with CCL2 in peripheral blood (PB) and synovial tissues (ST) of RA patients based on our previous work about chemokine signaling pathway involvedin the activation of CCL2 production in collagen-induced arthritis rat ST. Materials and Methods: Total RNA was isolated from PB leukocytes and synoviumof the knee joint in both RA patients and control populations. Real-time polymerasechain reaction was used to determine CCL4, CCR5, c-Jun, c-Fos, and CCL2 expressions. Serum level of CCL2 was assessed by enzyme-linked immunosorbent assay, and the production of CCL2 in ST was analyzed immunohistochemically. Results: The expressions of CCL4, CCR5, c-Jun, c-Fos, and CCL2 messenger RNA in RA patients were significantly higher than those in healthy controls, both in ST and on PB leukocyte. Serum CCL2 levels were elevated in RA patients. Histological examination of rheumatoid joints revealed extensive CCL2 expression in RA ST. Conclusion: CCL2, CCL4, c-Jun, c-Fos, and CCR5 may play an important role in the recruitment of PB leukocytes into the RA joints. These data provide evidence that the chemokine signaling pathway is involved in CCL2 expression in RA patient tissues, which may contribute to chronic inflammation associated with RA. Targetingthis signaling pathway may provide a novel therapeutic avenue in RA.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Lin, Yu-Zhang,Shi, Li-Bao,Yao, Liang-Zhong,Ni, Yi-Xin,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

Elevated FBXL6 expression in hepatocytes activates VRK2-transketolase-ROS-mTOR-mediated immune evasion and liver cancer metastasis in mice

Zhang Jie,Lin Xiao-Tong,Yu Hong-Qiang,Fang Lei,Wu Di,Luo Yuan-Deng,Zhang Yu-Jun,Xie Chuan-Ming 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Metastatic hepatocellular carcinoma (HCC) is the most lethal malignancy and lacks effective treatment. FBXL6 is overexpressed in human hepatocellular carcinoma (HCC), but whether this change drives liver tumorigenesis and lung metastasis in vivo remains unknown. In this study, we aimed to identify FBXL6 (F-Box and Leucine Rich Repeat Protein 6) as a key driver of HCC metastasis and to provide a new paradigm for HCC therapy. We found that elevated FBXL6 expression in hepatocytes drove HCC lung metastasis and was a much stronger driver than Kras mutation (KrasG12D/+;Alb-Cre), p53 haploinsufficiency (p53+/-) or Tsc1 loss (Tsc1fl/fl;Alb-Cre). Mechanistically, VRK2 promoted Thr287 phosphorylation of TKT and then recruited FBXL6 to promote TKT ubiquitination and activation. Activated TKT further increased PD-L1 and VRK2 expression via the ROS-mTOR axis, leading to immune evasion and HCC metastasis. Targeting or knockdown of TKT significantly blocked FBXL6-driven immune evasion and HCC metastasis in vitro and in vivo. Notably, the level of active TKT (p-Thr287 TKT) was increased and was positively correlated with the FBXL6 and VRK2 expression levels in HCC patients. Our work provides novel mechanistic insights into FBXL6-driven HCC metastasis and suggests that targeting the TKT-ROS-mTOR-PD-L1/VRK2 axis is a new paradigm for treating patients with metastatic HCC with high FBXL6 expression.

Risk Factors for Cervical Cancer in Rural Areas of Wuhan China: a Matched Case-control Study

Zhang, Bin,Zhou, Ai-Fen,Zhu, Chang-Cai,Zhang, Ling,Xiang, Bing,Chen, Zhong,Hu, Rong-Hua,Zhang, Ya-Qi,Qiu, Lin,Zhang, Yi-Ming,Xiong, Chao-Du,Du, Yu-Kai,Shi, Yu-Qin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

Recombinant Human Thioredoxin-1 Protects Macrophages from Oxidized Low-Density Lipoprotein-Induced Foam Cell Formation and Cell Apoptosis

Zhang, Hui,Liu, Qi,Lin, Jia-Le,Wang, Yu,Zhang, Ruo-Xi,Hou, Jing-Bo,Yu, Bo The Korean Society of Applied Pharmacology 2018 Biomolecules & Therapeutics(구 응용약물학회지) Vol.26 No.2

Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and apoptosis play critical roles in the pathogenesis of atherosclerosis. Thioredoxin-1 (Trx) is an antioxidant that potently protects various cells from oxidative stress-induced cell death. However, the protective effect of Trx on ox-LDL-induced macrophage foam cell formation and apoptosis has not been studied. This study aims to investigate the effect of recombinant human Trx (rhTrx) on ox-LDL-stimulated RAW264.7 macrophages and elucidate the possible mechanisms. RhTrx significantly inhibited ox-LDL-induced cholesterol accumulation and apoptosis in RAW264.7 macrophages. RhTrx also suppressed the ox-LDL-induced overproduction of lectin-like oxidized LDL receptor (LOX-1), Bax and activated caspase-3, but it increased the expression of Bcl-2. In addition, rhTrx markedly inhibited the ox-LDL-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38 mitogen-activated protein kinases (MAPK). Furthermore, anisomycin (a p38 MAPK activator) abolished the protective effect of rhTrx on ox-LDL-stimulated RAW264.7 cells, and SB203580 (a p38 MAPK inhibitor) exerted a similar effect as rhTrx. Collectively, these findings indicate that rhTrx suppresses ox-LDL-stimulated foam cell formation and macrophage apoptosis by inhibiting ROS generation, p38 MAPK activation and LOX-1 expression. Therefore, we propose that rhTrx has therapeutic potential in the prevention and treatment of atherosclerosis.

Scutellaria Extract Decreases the Proportion of Side Population Cells in a Myeloma Cell Line by Down-regulating the Expression of ABCG2 Protein

Lin, Mei-Gui,Liu, Li-Ping,Li, Chen-Yin,Zhang, Meng,Chen, Yuling,Qin, Jian,Gu, Yue-Yu,Li, Zhi,Wu, Xin-Lin,Mo, Sui-Lin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background and Aims: Scutellaria is one of the most popular traditional Chinese herbal remedies against various human diseases, including cancer. In this study, we examined the active effects of Scutellaria extract and its main flavonoid constituents on the proportion of side population cells within human multiple myeloma cell line RPMI8226 in vitro and explored the potential molecular mechanisms involved. Materials and Methods: The contents of flavonoids in ethanolic extract of Scutellaria baicalensis Georgi were determined using high performance liquid chromatography. The antiproliferative effect of the ethanolic extract on RPMI-8226 was determined by CCK assay. Apoptosis was measured by annexin combining with propidium iodide in a flow cytometer. Cell cycle analysis was performed by propidium iodide staining in combination with flow cytometry analysis. Hoechst 33342 exclusion assay was used for the identification of side population within RPMI8226 cells. The expression of ABCG2 protein was assessed by Western blotting assay. Results: The content of major flavonoids constitutents of Scutellaria extract was baicalin (10.2%), wogonoside (2.50%), baicalein (2.29%), and wogonin (0.99%), respectively. The crude Scutellaria extract did not show significant anti-proliferative effect, apoptosis induction and cell cycle arrest in RPMI-8226 within the concentrations of $1-75{\mu}g/mL$. However, the ethanolic extract, baicalein, wogonin and baicalin reduced the side population cells in RPMI-8226, and data showed that baicalein and wogonin had stronger inhibitory effects. Correspondingly, they also exhibited significant effects on decreasing the expression level of ABCG2 protein in RPMI-8226 in vitro. Conclusions: Our results for the first time demonstrated a novel mechanism of action for Scutellaria extract and its main active flavonoids, namely targeting SP cells by modulating the expression of ABCG2 protein. This study provides an insight for new therapeutic strategies targeting cancer stem cells of multiple myeloma.

Low-voltage-drive and high output current ZnO thin-film transistors with sputtering SiO2 as gate insulator

L. Zhang,J. Li,X.W. Zhang,D.B. Yu,H.P. Lin Khizar-ul-Haq,X.Y. Jiang,Z.L. Zhang 한국물리학회 2010 Current Applied Physics Vol.10 No.5

Low-voltage-drive ZnO thin-film transistors (TFTs) with room-temperature radio frequency magnetron sputtering SiO2 as the gate insulator were fabricated successfully on the glass substrate. The ZnO-TFT operates in the enhancement mode with a threshold voltage of 4.2 V, a field effect mobility of 11.2 ㎠/V s, an on/off ratio of 3.1 × 106 and a subthreshold swing of 0.61 V/dec. The drain current can reach to 1 mA while the gate voltage is only of 12 V and drain voltage of 8 V. The C–V characteristics of a MOS capacitor with the structure of ITO/SiO2/ZnO/Al was investigated. The carrier concentration ND in the ZnO active layer was determined, the calculated ND is 1.81 × 1016 cm−3, which is the typical value of undoped ZnO film used as the channel layer for ZnO-TFT devices. The experiment results show that SiO2 film is a promising insulator for the low voltage and high drive capability oxide TFTs.

Electrospun Polyphenylquinoxaline Ultrafine Non-woven Fibrous Membranes with Excellent Thermal and Alkaline Resistance: Preparation and Characterization

Chen-yu Guo,Lu-meng Yin,Jin-gang Liu,Xin-ke Wang,Na Zhang,Lin Qi,Yan Zhang,Xiao Wu,Xiu-min Zhang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.12

A series of polyphenylquinoxaline (PPQ) ultrafine non-woven fibrous membranes have been first successfullyprepared via the electrospinning procedure with the soluble PPQ solutions as the starting materials. For this purpose, variousorgano-soluble PPQ resins were synthesized via the one-step high temperature polycondensation procedure from thearomatic ether-bridged bis(α-diketone) and bis(o-diamine) monomers. Flexible ether linkages and pendant bulky phenylsubstituents endowed the PPQ resins good solubility in polar aprotic solvents. The high-molecular-weight PPQ resins weredissolved in N-methyl-2-pyrrolidone (NMP) to afford the PPQ electrospinning solution except PPQ-Ia derived from 4,4'-oxydibenzil (ODB) and 3,3'-diaminobenzidine (DAB) due to the limited solubility in the solvent. All the derived PPQultrafine non-woven fibrous membranes maintained good structure integrity after hydrolysis aging either at room temperature(25 oC) for 72 h or at refluxing temperature (100 oC) for 24 h in an aqueous sodium hydroxide (NaOH) solution at a solidcontent of 20 wt%. Comparatively, the polyimide (PI) reference electrospun membrane (PI-ref) derived from 1,2,4,5-pyrromellitic anhydride (PMDA) and 4,4'-oxydianiline (ODA) lost its original structure only after boiling in the same NaOHsolution within 3 h. In addition, the developed PPQ ultrafine non-woven fibrous membranes exhibited good thermal stabilitywith the 5 % weight loss temperatures (T5%) higher than 555.0 oC in nitrogen and glass transition temperatures (Tg) in therange of 248.1-266.1 oC, respectively.

Chemically Modified Sepharose as Support for the Immobilization of Cholesterol Oxidase

( Hai Lin Yang ),( Yi Chen ),( Yu Xin ),( Ling Zhang ),( Yu Ran Zhang ),( Wu Wang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.9

Because the cholesterol oxidase from Brevibacterium sp. M201008 was not as stable as the free enzyme form, it had been covalently immobilized onto chemically modified Sepharose particles via N-ethyl-N`-3-dimethylaminopropyl carbodiimide. The optimum immobilization conditions were determined, and the immobilized enzyme activity obtained was 12.01 U/g Sepharose-ethylenediamine. The immobilization of the enzyme was characterized by Fourier transform infrared spectroscopy. The immobilized enzyme exhibited the maximal activity at 35oC and pH 7.5, which was unchanged compared with the free form. After being repeatedly used 20 times, the immobilized enzyme retained more than 40.43% of its original activity. The immobilized enzyme showed better operational stability, including wider thermal and pH ranges, and retained 62.87% activity after 20 days of storage at 4oC, which was longer than the free enzyme.