Numerical simulation of slit wall effect on the Taylor vortex flow with radial temperature gradient

Dong Liu,Chang-qing Chao,Fang-neng Zhu,Xi-qiang Han,Chengtang Liu 한국유체기계학회 2015 International journal of fluid machinery and syste Vol.8 No.4

Numerical simulation was applied to investigate the Taylor vortex flow inside the concentric cylinders with a constant radial temperature gradient. The reliability of numerical simulation method was verified by the experimental results of PIV. The radial velocity and temperature distribution in plain and 12-slit model at different axial locations were compared, and the heat flux distributions along the inner cylinder wall at different work conditions were obtained. In the plain model, the average surface heat flux of inner cylinder increased with the inner cylinder rotation speed. In slit model, the slit wall significantly changed the distribution of flow field and temperature in the annulus gap, and the radial flow was strengthen obviously , which promoted the heat transfer process at the same working condition.

Rubrofusarin-6-β-gentiobioside inhibits lipid accumulation and weight gain by regulating AMPK/mTOR signaling

Han, Yo-Han,Kee, Ji-Ye,Park, Seong-Hwan,Mun, Jeong-Geon,Jeon, Hee-Dong,Park, Jinbong,Zou, Qin-Peng,Liu, Xiang-Qian,Hong, Seung-Heon Elsevier 2019 Phytomedicine Vol.62 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Although rubrofusarin-6-β-gentiobioside (RFG), which is a component of <I>Cassiae tora</I> seed, could likely regulate hyperlipidemia, its anti-obesity effect and related mechanism have not been elucidated.</P> <P><B>Purpose</B></P> <P>The aim of this study was to examine whether RFG can ameliorate obesity and the mechanism of lipid accumulation regulated by RFG.</P> <P><B>Study design</B></P> <P>In <I>in vitro</I> experiments, we confirmed the anti-adipogenic effect of RFG using 3T3-L1 cells and human adipose mesenchymal stem cells (hAMSCs). To confirm the anti-obesity effect, High-Fat Diet (HFD)-induced obese mice were selected as a model.</P> <P><B>Methods</B></P> <P>We investigated anti-adipogenic effects of RFG using MTS assay, Oil Red O Staining, real-time RT-PCR, western blot analysis, and immunofluorescence staining. The anti-obesity effect of RFG was confirmed in HFD-induced mice model using hematoxylin and eosin staining and serum analysis.</P> <P><B>Results</B></P> <P>RFG inhibited lipid accumulation in 3T3-L1 cells and hAMSCs by reducing expression of mammalian targets of rapamycin (mTOR), peroxisome proliferator-activated receptor (PPAR)γ, and CCAAT-enhancer binding protein (C/EBP)α. RFG phosphorylated AMP-activated protein kinase (AMPK) in a liver kinase B (LKB) 1-independent manner. Moreover, the anti-adipogenic effect of RFG was blocked by AMPK inhibitor. These results suggest that RFG inhibits lipid accumulation via AMPK signaling. Furthermore, RFG reduced the body weight, size of epididymal white adipose tissue (eWAT), and fatty liver in the mice. RFG also suppressed levels of adipogenic factors PPARγ, C/EBPα, FAS, LPL, and aP2) by activating AMPK in the eWAT and liver.</P> <P><B>Conclusion</B></P> <P>RFG can ameliorate obesity, and thus, could be used as a therapeutic agent for treating obesity.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Centrifuge Model Tests and Numerical Simulations of the Landslide Evolution Process

Han-Dong Liu,Jia-Xing Chen,Wen-Xi Han,Ye Wu,Dong-Dong Li 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.6

Centrifuge model tests and numerical simulations were performed to study the landslide evolution process and failure mechanism. A TLJ-500 geotechnical centrifuge was used for the experiments and landslide deformation and stress was monitored using high-precision differential displacement sensors and earth pressure micro-sensors. Discrete element numerical simulations were performed using PFC2D based on the experimental results. The findings show that the landslide evolution process can be divided into three stages: 1) compaction and consolidation; 2) uniform deformation; and 3) accelerated deformation and failure. The numerical simulation results verify the distinct stage characteristics of the landslide evolution process. According to the migration of microscopic soil mass particles within the landslide, stage 3) can be further divided into a deformation development stage and instability and failure stage. The simulation displacement monitoring curves and displacement map show distinct deformation characteristics and displacement indicators from stages 2) to 3) and from the deformation development stage to the instability and failure stage. The experimental and numerical results reveal the landslide failure mechanism: the upper part of the landslide thrusts and slides; the middle part squeezes; the lower part collapses; and shear plane penetration leads to landslide failure.

An Epigenetic Mechanism Underlying Doxorubicin Induced EMT in the Human BGC-823 Gastric Cancer Cell

Han, Rong-Fei,Ji, Xiang,Dong, Xing-Gao,Xiao, Rui-Jing,Liu, Yan-Ping,Xiong, Jie,Zhang, Qiu-Ping Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.10

The epithelial to mesenchymal transition (EMT) is a key step during embryonic morphogenesis and plays an important role in drug resistance and metastasis in diverse solid tumors. We previously reported that 48 h treatment of anti-cancer drug doxorubicin could induce EMT in human gastric cancer BGC-823 cells. However, the long term effects of this transient drug treatment were unknown. In this study we found that after 48 h treatment with $0.1{\mu}g/ml$ doxorubicin, most cells died during next week, while a minor population of cells survived and formed colonies. We propagated the surviving cells in drug free medium and found that these long term cultured drug survival cells (abbreviated as ltDSCs) retained a mesenchymal-like cell morphology, and expressed high levels of EMT-related molecules such as vimentin, twist and ${\beta}$-catenin. The expression of chromatin reprogramming factors, Oct4 and c-myc, were also higher in ltDSCs than parental cells. We further demonstrated that the protein level of p300 was upregulated in ltDSCs, and inhibition of p300 by siRNA suppressed the expression of vimentin. Moreover, the ltDSCs had higher colony forming ability and were more drug resistant when compared to parental cells. Our results suggested that an epigenetic mechanism is involved in the EMT of ltDSCs.

LKB1/AMPK/mTOR Signaling Pathway in Non-small-cell Lung Cancer

Han, Dong,Li, Shao-Jun,Zhu, Yan-Ting,Liu, Lu,Li, Man-Xiang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Links between cancer and metabolism have been suggested for a long time but compelling evidence for this hypothesis came from the recent molecular characterization of the LKB1/AMPK signaling pathway as a tumor suppressor axis. Besides the discovery of somatic mutations in the LKB1 gene in certain type of cancers, a critical emerging point was that the LKB1/AMPK axis remains generally functional and could be stimulated by pharmacological molecules such as metformin in cancer cells. In addition, AMPK plays a central role in the control of cell growth, proliferation and autophagy through the regulation of mTOR activity, which is consistently deregulated in cancer cells. Targeting of AMPK/mTOR is thus an attractive strategy in the development of therapeutic agents against non-small-cell lung cancer (NSCLC). In this review, the LKB1/AMPK/mTOR signaling pathway is described, highlighting its protective role, and opportunities for therapeutic intervention, and clinical trials in NSCLC.

mRNA Expression and Clinical Significance of ERCC1, BRCA1, RRM1, TYMS and TUBB3 in Postoperative Patients with Non-Small Cell Lung Cancer

Han, Yi,Wang, Xiao-Bin,Xiao, Ning,Liu, Zhi-Dong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Background: To explore mRNA expression and clinical significance of ERCC1, BRCA1, RRM1, TYMS and TUBB3 genes in tumor tissue of postoperative patients with non-small cell lung cancer (NSCLC). Materials and Methods: Sixty NSCLC patients undergoing radical operation in our hospital from Nov., 2011 to Jun., 2012 were selected. Plasmid standards of ERCC1, BRCA1, RRM1, TYMS and TUBB3 were established and standard curves were prepared by SYBR fluorescent real-time quantitative PCR analysis. Samples from tumor centers were taken to detect mRNA expression of ERCC1, BRCA1, RRM1, TYMS and TUBB3 genes in cancerous tissue during operation. The total mRNA expression quantities were compared according to different clinical characteristics. Results: The total expression quantities of 5 genotypes from high to low were ERCC1>RRM1>TUBB3>TYMS>BRCA1 in turn. By pairwise comparisons, other differences showed statistical significance (p<0.05 or p<0.01) except for TYMS and TUBB3 (p>0.05); the low expression rates from high to low were ERCC1>TYMS>TUBB3>TUBB3>RRM1>BRCA1 in turn. The expression quantities of BRCA1, RRM1 and TYMS in males, smokers and patients without adenocarcinoma were all significantly higher than that in females, non-smokers and patients with adenocarcinoma, and significant differences were present (p<0.05 or p<0.01). In terms of pathological staging, the expression quantities of BRCA1, RRM1 and TYMS in phases IIa~IIb and IIIa~IIIb had a tendency to be greater than in phases I and IV. Conclusions: Resistance to chemotherapy and sensitivity to targeted therapy differ among patients with NSCLC. Differences in gene expression in different individuals were also revealed. Only according to personalized detection results can individualized therapeutic regimens be worked out, which is a new direction for oncotherapy.

Durable Hydrophilic Modification of Wool Scales with Reactive Surfactants in Saturated Neutral Salt System

Han Tian,Baojiang Liu,Xia Dong,Qiangqiang Zhao,Jinxin He 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

In this study, a new reactive surfactant was synthesized from cyanuric chloride and Jeffamine ED-600 or ED-2003,and then applied to the pre-reduced wool fabric in saturated neutral salt solution at low temperature. This treatment conditioninhibited the wool swelling, making the surfactant mainly covalently bond on the scales of wool. The structure of surfactantwas confirmed by 13C NMR, and the modified wool fabrics were characterized by FTIR-ATR, XPS, and SEM after carefullywashing with acetone and water. The wettability, liquid transport ability, antistatic and mechanical properties of the modifiedwool fabrics were also investigated. The results suggested that this modification method could significantly improve thehydrophilicity of wool surface, enhance the transport ability of liquid through the fabric and increase the antistatic propertiesof the fabric under low humidity conditions. Importantly, the modified fabric has robust washing fastness, with no seriousdamage to wool.

Cytisine, a Partial Agonist of α4β2 Nicotinic Acetylcholine Receptors, Reduced Unpredictable Chronic Mild Stress-Induced Depression-Like Behaviors

Han, Jing,Wang, Dong-sheng,Liu, Shui-bing,Zhao, Ming-gao The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.3

Cytisine (CYT), a partial agonist of ${\alpha}4{\beta}2-nicotinic$ receptors, has been used for antidepressant efficacy in several tests. Nicotinic receptors have been shown to be closely associated with depression. However, little is known about the effects of CYT on the depression. In the present study, a mouse model of depression, the unpredictable chronic mild stress (UCMS), was used to evaluate the activities of CYT. UCMS caused significant depression-like behaviors, as shown by the decrease of total distances in open field test, and the prolonged duration of immobility in tail suspension test and forced swimming test. Treatment with CYT for two weeks notably relieved the depression-like behaviors in the UCMS mice. Next, proteins related to depressive disorder in the brain region of hippocampus and amygdala were analyzed to elucidate the underlying mechanisms of CYT. CYT significantly reversed the decreases of 5-HT1A, BDNF, and mTOR levels in the hippocampus and amygdala. These results imply that CYT may act as a potential anti-depressant in the animals under chronic stress.

Synthesis of Sc and V-doped TiO2 nanoparticles and photodegradation of rhodamine-B

Dong Ri Zhang,Hai Lan Liu,Shun Yu Han,Wen Xiang Piao 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.6

Anatase TiO2 nanoparticles doped with Sc and V were synthesized and their photocatalytic activities were evaluated through the photodegradation of rhodamine-B under UV irradiation. TiO2 shows the highest photocatalytic activity and Sc doped TiO2 and V doped TiO2 show lower photocatalytic activity than TiO2. In contrast, Sc and V codoped TiO2 shows no any photocatalytic activity. The reasons for the decrease in photocatalytic activity is due to the presence of surficial Sc2O3 islands covering the reactive sites for Sc doped TiO2 and the increased e-/h+ pair recombination resulted from the high level substitutional V(IV) ions for V doped TiO2, respectively.

Diffusion-Weighted Imaging for the Left Hepatic Lobe has Higher Diagnostic Accuracy for Malignant Focal Liver Lesions

Han, Xue,Dong, Yin,Xiu, Jian-Jun,Zhang, Jie,Huang, Zhao-Qin,Cai, Shi-Feng,Yuan, Xian-Shun,Liu, Qing-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: This study was conducted to investigate whether apparent diffusion coefficient (ADC) measurements by dividing the liver into left and right hepatic lobes may be utilized to improve the accuracy of differential diagnosis of benign and malignant focal liver lesions. Materials and Methods: A total of 269 consecutive patients with 429 focal liver lesions were examined by 3-T magnetic resonance imaging that included diffusion-weighted imaging. For 58 patients with focal liver lesions of the same etiology in left and right hepatic lobes, ADCs of normal liver parenchyma and focal liver lesions were calculated and compared using the paired t-test. For all 269 patients, ADC cutoffs for focal liver lesions and diagnostic accuracy in the left hepatic lobe, right hepatic lobe and whole liver were evaluated by receiver operating characteristic curve analysis. Results: For the group of 58 patients, mean ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. For differentiating malignant lesions from benign lesions in all patients, the sensitivity and specificity were 92.6% and 92.0% in the left hepatic lobe, 94.4% and 94.4% in the right hepatic lobe, and 90.4% and 94.7% in the whole liver, respectively. The area under the curve of the right hepatic lobe, but not the left hepatic lobe, was higher than that of the whole liver. Conclusions: ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. Optimal ADC cutoff for focal liver lesions in the right hepatic lobe, but not in the left hepatic lobe, had higher diagnostic accuracy compared with that in the whole liver.