Effects of Polymerization and Spinning Conditions on Mechanical Properties of PAN Precursor Fibers

Qi-Feng Qin,Yong-Qiang Dai,Kai Yi,Li Zhang,Seung-Kon Ryu,Ri-Guang Jin 한국탄소학회 2010 Carbon Letters Vol.11 No.3

PAN precursor fibers were produced via wet-spinning process, and effects of polymerization and spinning processes, especially the stretching process, were investigated on mechanical properties and micro-morphologies of precursor fibers. An increase in molecular weight, dope solid and densification and a decrease in surface defects were possible by controlling polymerization temperature, the number of heating rollers for densification and the jet stretch ratio, which improved the mechanical properties of precursor fibers. The curves for strength, modulus, tensile power and diameter as a function of stretch ratio can be divided into three stages: steady change area, little change area and sudden change area. With the increase of stretch ratio, the fiber diameter became smaller, the degree of crystallization increased and the structure of precursor fibers became compact and homogeneous, which resulted in the increase of strength, modulus and tensile power of precursor fibers. Empirical relationship between fiber strength and stretch ratio was studied by using the sub-cluster statistical theory. It was successfully predicted when the strengths were 0.8 GPa and 1.0 GPa under a certain technical condition, the corresponding stretch ratio of the fiber were 11.16 and 12.83 respectively.

Total ginsenosides suppress monocrotaline-induced pulmonary hypertension in rats: involvement of nitric oxide and mitogen-activated protein kinase pathways

Qin, Na,Yang, Wei,Feng, Dongxu,Wang, Xinwen,Qi, Muyao,Du, Tianxin,Sun, Hongzhi,Wu, Shufang The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.3

Background: Ginsenosides have been shown to exert beneficial pharmacological effects on the central nervous, cardiovascular, and endocrine systems. We sought to determine whether total ginsenosides (TG) inhibit monocrotaline (MCT)-induced pulmonary hypertension and to elucidate the underlying mechanism. Methods: MCT-intoxicated rats were treated with gradient doses of TG, with or without $N^G$-nitro-$\small{L}$-arginine methyl ester. The levels of molecules involving the regulation of nitric oxide and mitogen-activated protein kinase pathways were determined. Results: TG ameliorated MCT-induced pulmonary hypertension in a dose-dependent manner, as assessed by the right ventricular systolic pressure, the right ventricular hypertrophy index, and pulmonary arterial remodeling. Furthermore, TG increased the levels of pulmonary nitric oxide, endothelial nitric oxide synthase, and cyclic guanosine monophosphate. Lastly, TG increased mitogen-activated protein kinase phosphatase-1 expression and promoted the dephosphorylation of extracellular signal-regulated protein kinases 1/2, p38 mitogen-activated protein kinase, and c-Jun NH2-terminal kinase 1/2. Conclusion: TG attenuates MCT-induced pulmonary hypertension, which may involve in part the regulation of nitric oxide and mitogen-activated protein kinase pathways.

IL-33 promotes IL-10 production in macrophages: a role for IL-33 in macrophage foam cell formation

Hai-Feng Zhang,Mao-Xiong Wu,Yong-Qing Lin,Shuang-Lun Xie,Tu-Cheng Huang,Pin-Ming Liu,Ru-Qiong Nie,Qin-Qi Meng,Nian-Sang Luo,Yang-Xin Chen,Jing-Feng Wang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

We evaluated the role of IL-10- in IL-33-mediated cholesterol reduction in macrophage-derived foam cells (MFCs) and the mechanism by which IL-33 upregulates IL-10. Serum IL-33 and IL-10 levels in coronary artery disease patients were measured. The effects of IL-33 on intra-MFC cholesterol level, IL-10, ABCA1 and CD36 expression, ERK 1/2, Sp1, STAT3 and STAT4 activation, and IL-10 promoter activity were determined. Core sequences were identified using bioinformatic analysis and sitespecific mutagenesis. The serum IL-33 levels positively correlated with those of IL-10. IL-33 decreased cellular cholesterol level and upregulated IL-10 and ABCA1 but had no effect on CD36 expression. siRNA-IL-10 partially abolished cellular cholesterol reduction and ABCA1 elevation by IL-33 but did not reverse the decreased CD36 levels. IL-33 increased IL-10 mRNA production but had little effect on its stability. IL-33 induced ERK 1/2 phosphorylation and increased the luciferase expression driven by the IL-10 promoter, with the highest extent within the − 2000 to − 1752 bp segment of the 5′-flank of the transcription start site; these effects were counteracted by U0126. IL-33 activated Sp1, STAT3 and STAT4, but only the STAT3 binding site was predicted in the above segment. Site-directed mutagenesis of the predicted STAT3-binding sites (CTGCTTCCTGGCAGCAGAA→CTGCCTGGCAGCAGAA) reduced luciferase activity, and a STAT3 inhibitor blocked the regulatory effects of IL-33 on IL-10 expression. Chromatin immunoprecipitation (CHIP) confirmed the STAT3-binding sequences within the − 1997 to − 1700 and − 1091 to − 811 bp locus regions. IL-33 increased IL-10 expression in MFCs via activating ERK 1/2 and STAT3, which subsequently promoted IL-10 transcription and thus contributed to the beneficial effects of IL-33 on MFCs.

Predicting connection integrity with consideration of thermo stress

Yong Qin Cheng,Shuo Qiong Liu,Feng Zhong Qi,Hui Ting Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

In the conventional gas seal analysis of special threaded joints, the influence of temperature stress caused by the difference between formation temperature and fluid temperature in casing is often neglected. However, the influence mechanism of temperature stress is prerequisite information for accurately predicting the safe operating conditions that prevent a premium connection from being damaged. In this paper, we propose a model that includes these effects to predict the safe operating pressures and temperatures that will prevent seal failure. For the temperature stress, we propose a finite element model of thermal solid coupling. Subsequent stress changes are evaluated by a fully coupled model of thermal solid coupling to analyze the mechanical behavior of the premium connection. We predict the safe operating envelope (SOE) for premium connection failures caused by pressure and temperature perturbations after make-up. Our model predicts that radial pressure is a key factor for connection failure, especially for rapid temperature changes. If the formation temperature is high and the casing fluid temperature is low, the influence of temperature stress will increase under this working condition, resulting in an increase in the probability of failure of premium connections. Compared with conventional premium connection models, the model of thermal solid coupling predicts a smaller SOE when heating the internal casing fluid and a larger envelope when cooling the internal casing fluid. Finally, the heating rate was considered with respect to field applications. The heating rate was also considered, and slower heating/cooling rates can prevent damage to the seal integrity. Finally, the model was applied to explain several laboratory and field experiments and achieved good matches.

Human Recombinant Endostatin Combined with Cisplatin Based Doublets in Treating Patients with Advanced NSCLC and Evaluation by CT Perfusion Imaging

Zhang, Feng-Lin,Gao, Er-Yun,Shu, Rong-Bao,Wang, Hui,Zhang, Yan,Sun, Peng,Li, Min,Tang, Wei,Jiang, Bang-Qin,Chen, Shuang-Qi,Cui, Fang-Bo Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Aims: To study the effectiveness of human recombinant endostatin injection (Endostar(R)) combined with cisplatin doublets in treating advanced non-small cell lung cancer (NSCLC), and to evaluate outcome by CT perfusion imaging. Methods: From April 2011 to September 2014, 76 patients with advanced NSCLC who were treated with platinum-based doublets were divided into group A (36 patients) and group B (40 patients). Endostar(R) 15mg/day was administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A, and combined with chemotherapy from the first day in Group B. Endostar(R) in the two groups was injected intravenously for 14 days. Results: Treatment effectiveness in the two groups differed with statistical significance (p<0.05). Effectiveness evaluated by CT perfusion imaging, BF, BV, MTT and PS also demonstrated significant differences (all p<0.05). Adverse reactions in the two groups did not significantly vary (p> 0.05). Conclusions: The response rate with Endostar(R) administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A was better than Endostar(R) combined with chemotherapy from the first day, and CT perfusion imaging could be a reasonable method for evaluation of patient outcomes.

Purification and Cloning of an Extracellular Serine Protease from the Nematode-Trapping Fungus Monacrosporium cystosporium

( Jin Kui Yang ),( Feng Ping Ye ),( Qi Li Mi ),( Song Qing Tang ),( Juan Li ),( Ke Qin Zhang ) 한국미생물 · 생명공학회 2008 Journal of microbiology and biotechnology Vol.18 No.5

In-Situ Dehydration Test of Shield Spoil in Mudstone and Pebble Soil Composite Stratum

Dongping Zhao,Sixun Wen,Qi He,Feng Wang,Baihao Zhang,Zhuyan Wang,Huachang Fang,Ye Qin 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1

When earth pressure balance (EPB) shield machine is driving in mudstone sand pebble composite stratum, it will produce a large amount of spoil with high water content. The high moisture content of spoil not only increases the difficulty and cost of transportation, but also easily leads to environmental pollution problems. In this paper, based on the shield tunnel project of Chengdu Metro Line 30, the hydraulic characteristic of shield spoil was tested, and on this basis, laboratory tests of shield spoil dehydration were carried out according to the designed precipitation scheme. The results show that: 1) The moisture content of the EPB shield spoil in the mudstone sand pebble composite stratum is as high as 55.2%, and its permeability coefficient is basically the same as that of silt, and the shield residue has the condition of in-situ dehydration. 2) The dehydration amount and residue moisture content of spoil in slope-type spoil pit showed a linear relationship with time, and the dehydration rate is slow and the total precipitation is less. In other schemes, the dehydration amount and water content of spoil increase rapidly in the first 24 hours and slowly in the later period. 3) Considering the total amount and speed of dehydration within 24 hours, the dehydration effect of spoil pit is ranked from high to low: 3D gravel cage wall spoil pit > 3D spoil pit with vacuum pumping > 3D permeable stone spoil pit > 3D spoil pit > Slope-type spoil pit. 4) 3D gravel cage wall spoil pit has high dewatering efficiency, and vacuum pumping can assist the discharge of water. It is recommended to use 3D gravel cage wall spoil pit and vacuum pumping scheme for on-site EPB tunnel spoil dewatering.

Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi in Captive Non-Human Primates in Qinling Mountains

Shuai-Zhi Du,Guang-Hui Zhao,Jun-Feng Shao,Yan-Qin Fang,Ge-Ru Tian,Long-Xian Zhang,Rong-Jun Wang,Hai-Yan Wang,Meng Qi,San-Ke Yu 대한기생충학열대의학회 2015 The Korean Journal of Parasitology Vol.53 No.4

LY294002 Induces G0/G1 Cell Cycle Arrest and Apoptosis of Cancer Stem-like Cells from Human Osteosarcoma Via Down-regulation of PI3K Activity

Gong, Chen,Liao, Hui,Wang, Jiang,Lin, Yang,Qi, Jun,Qin, Liang,Tian, Lin-Qiang,Guo, Feng-Jing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Osteosarcoma, the most common primary mesenchymal malignant tumor, usually has bad prognosis in man, with cancer stem-like cells (CSCs) considered to play a critical role in tumorigenesis and drug-resistance. It is known that phosphatidylinositol 3-kinase (PI3K) is involved in regulation of tumor cell fates, such as proliferation, cell cycling, survival and apoptosis. Whether and how PI3K and inhibitors might cooperate in human osteosarcoma CSCs is still unknown. We therefore evaluated the effects of LY294002, a PI3K inhibitor, on the cell cycle and apoptosis of osteosarcoma CSCs in vitro. LY294002 prevented phosphorylation of protein kinase B (PKB/Akt) by inhibition of PI3K phosphorylation activity, thereby inducing G0/G1 cell cycle arrest and apoptosis in osteosarcoma CSCs. Further studies also demonstrated that apoptosis induction by LY294002 is accompanied by activation of caspase-9, caspase-3 and PARP, which are involved in the mitochondrial apoptosis pathway. Therefore, our results indicate PI3K inhibitors may represent a potential strategy for managing human osteosarcoma via affecting CSCs.

Anti-tumor Activity and Apoptosis-regulation Mechanisms of Bufalin in Various Cancers: New Hope for Cancer Patients

Yin, Pei-Hao,Liu, Xuan,Qiu, Yan-Yan,Cai, Jian-Feng,Qin, Jian-Min,Zhu, Hui-Rong,Li, Qi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

The induction of apoptosis in target cells is a key mechanism for most anti-tumor therapies. Bufalin is a cardiotonic steroid that has the potential to induce differentiation and apoptosis of tumor cells. Research on bufalin has so far mainly involved leukemia, prostate cancer, gastric cancer and liver cancer, and has been confined to in vitro studies. The bufadienolides bufalin and cinobufagin have been shown to induce apoptosis in a wide spectrum of cancer cell. The present article reviews the anticancer effects of bufalin. It induces apoptosis of lung cancer cells via the PI3K/Akt pathway and also suppressed the proliferation of human non-small cell lung cancer A549 cell line in a time and dose dependent manner. Bufalin, bufotalin and gamabufotalin, key bufadienolides, significantly sensitize human breast cancer cells with differing ER-alpha status to apoptosis induction by the TNF-related apoptosis-inducing ligand (TRAIL). In addition, bufadienolides induce prostate cancer cell apoptosis more significantly than that in breast epithelial cell lines. Similar effects have been observed with hepatocellular carcinoma (HCC) but the detailed molecular mechanisms of inducing apoptosis in this case are still unclear. Bufalin exerts profound effects on leukemia therapy in vitro. Results of multiple studies indicate that bufalin has marked anti-tumor activities through its ability to induce apoptosis. Large-scale randomized, double-blind, placebo or positive drug parallel controlled studies are now required to confirm the efficacy and apoptosis-inducing potential of bufalin in various cancers in the cliniucal setting.