Thermal and Mechanical Response of Soil and Tunnel during Replacement of Shield Tail Brush by Freezing Method

Xu-Yang Wang,Da-Jun Yuan,Da-Long Jin,Wei-Lin Su 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.5

In the long-distance shield tunneling process, the shield tail brush needs to be replaced after wear failure, especially in cross-river and cross-sea tunnel projects. Taking the shield tail brush replacement project of Qingchun Road tunnel in Hangzhou, China as the research background, a three-dimensional sequential thermo-mechanical coupled numerical simulation was carried out to study the shield tail brush replacement with liquid nitrogen freezing by ABAQUS software. The development of temperature fields and displacement fields of soil, and the deformations of the tunnel sections along the longitudinal direction induced by freezing were obtained. The numerical model was further validated by site measurement. In addition, the effects of the frozen wall thickness, buried depth, excavation radius, and coefficients of linear thermal expansion of soils on the frost heave were studied.

Prognostic Significance of Overexpression of EZH2 and H3k27me3 Proteins in Gastric Cancer

He, Long-Jun,Cai, Mu-Yan,Xu, Guo-Liang,Li, Jian-Jun,Weng, Zi-Jin,Xu, Da-Zhi,Luo, Guang-Yu,Zhu, Sen-Lin,Xie, Dan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

The enhancer of zeste homolog 2 (EZH2) methyl transferase and histone 3 lysine 27 (H3K27me3) protein can repress gene transcription, and their aberrant expression has been observed in various human cancers. This study determined their expression levels in gastric cancer tissues with reference to clinicopathological features and patient survival. We collected 117 gastric cancer and corresponding normal tissues for immunohistochemistry analysis. In gastric cancers, 82/117 (70.1%) were positive for EZH2 and 66/117 (56.4%) for H3K27me3 proteins in contrast to only 5.41% and 7.25% of normal gastric mucosa specimens, respectively. Kaplan-Meier survival data showed the average overall and disease-free survival of EZH2 high expression patients was 25.2 and 20.2 months, respectively, shorter than that with EZH2 low expression (40.5 and 35.9 months). The average overall survival and disease-free survival of high H3K27me3 expression patients was 23.4 and 17.4 months, shorter than without H3K27me3 expression (37.6 and 34.5 months). The average overall survival and disease-free survival of patients with both EZH2 and H3K27me3 expression was 18.8 and 12.9 months, respectively, shorter than that with either alone (34.7 and 31.2 months) or with low levels of both (43.9 and 39.9 months). Multivariate Cox regression analysis showed that H3K27me3 and EZH2 expression, tumor size differentiation and clinical stage were all independent prognostic factors for predicting patient survival. This study demonstrated that detection of both EZH2 and H3K27me3 proteins can predict poor survival of gastric cancer patients, superior to single protein detection. In addition, H3K27me3 and EZH2 protein expression could predict lymph node metastasis.

A novel method for the discrimination of Hawthorn and its processed products using an intelligent sensory system and artificial neural networks

Da-Shuai Xie,Wei Peng,Jun-Cheng Chen,Liang Li,Chong-Bo Zhao,Shi-Long Yang,Min Xu,Chun-Jie Wu,Li Ai 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

Hawthorn (CFS) has commonly been applied as an important traditional Chinese medicine and food for thousands of years. The raw material of CFS is commonly processed by stir-frying to obtain yellow (CFY), dark brown (CFD), and carbon dark (CFC) colored products, which are used for different clinical uses. In this study, an intelligent sensory system (ISS) was used to obtain the color, gas, and flavor samples data, which were further employed to develop a novel and accurate method for the identification of CFS and its processed products using principal component analysis. Moreover, this research developed a model of an artificial neural network, which could be used to predict the total organic acid, total flavonoids, citric acid, hyperin, and 5-hydroxymethyl furfural via determination of the color, odor, and taste of a sample. In conclusion, the ISS and the artificial neural network are useful tools for rapid, accurate, and effective discrimination of CFS and its processed products.

Heavy concrete shielding properties for carbon therapy

Jin-Long Wang,Jiade J Lu,Da-Jun Ding,Wen-Hua Jiang,Ya-Dong Li,Rui Qiu,Hui Zhang,Xiao-Zhong Wang,Huo-Sheng Ruan,Yan-Bing Teng,Xiao-Guang Wu,Yun Zheng,Zi-Hao Zhao,Kai-Zhong Liao,Huan-Cheng Mai,Xiao-Dong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

A novel method for the discrimination of Hawthorn and its processed products using an intelligent sensory system and artificial neural networks

Xie, Da-Shuai,Peng, Wei,Chen, Jun-Cheng,Li, Liang,Zhao, Chong-Bo,Yang, Shi-Long,Xu, Min,Wu, Chun-Jie,Ai, Li 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

Hawthorn (CFS) has commonly been applied as an important traditional Chinese medicine and food for thousands of years. The raw material of CFS is commonly processed by stir-frying to obtain yellow (CFY), dark brown (CFD), and carbon dark (CFC) colored products, which are used for different clinical uses. In this study, an intelligent sensory system (ISS) was used to obtain the color, gas, and flavor samples data, which were further employed to develop a novel and accurate method for the identification of CFS and its processed products using principal component analysis. Moreover, this research developed a model of an artificial neural network, which could be used to predict the total organic acid, total flavonoids, citric acid, hyperin, and 5-hydroxymethyl furfural via determination of the color, odor, and taste of a sample. In conclusion, the ISS and the artificial neural network are useful tools for rapid, accurate, and effective discrimination of CFS and its processed products.

Mesenchymal-to-epithelial transition of osteoblasts induced by Fam20c knockout

Geng Ya-Wei,Zhang Zhen,Jin Han,Da Jun-Long,Zhang Kai,Wang Jian-Qun,Guo Yu-Yao,Zhang Bin,Li Ying 한국유전학회 2022 Genes & Genomics Vol.44 No.2

Background: Fam20c is intimately related to tissue development and diseases. At present, it has been reported that Fam20c regulates the mineralization of osteoblasts, but there are few reports on other effects. Objective: To study the effect of Fam20c on osteoblasts by knocking out the Fam20c gene. Methods: Fam20c knockout osteoblasts were constructed by transfecting mouse osteoblasts with lentivirus. The proliferation, migration and mineralization of Fam20c knockout cells were detected by CCK-8, scratch test and alizarin red staining assays. The subcellular structure was observed by transmission electron microscopy. RT-PCR was used to detect the differential expression of mesenchymal-to-epithelial transition (MET)-related marker genes and core transcription factors. The differential expression of MET-related proteins was detected by immunofluorescence or Western blot. Transcriptome analysis of Fam20c knockout osteoblasts was performed, and real-time PCR was used to verify transcriptome analysis related to MET. Results: The proliferation ability of osteoblasts was not significantly changed after Fam20c deletion, but the migration ability and mineralization ability were significantly weakened. There were tight junctions between Fam20c knockout cells. The expression of mesenchymal cell marker genes and core transcription factors was significantly decreased, and the expression of epithelial cell marker genes was significantly increased. The expression of mesenchymal cell marker proteins was significantly decreased, and the expression of epithelial cell marker proteins was significantly increased. Multiple signalling molecules and pathways involved in MET have changed. Conclusions: Knockdown of Fam20c resulted in MET. Fam20c affects the transcription of key factors in osteoblast MET.

Hydrogen sulfide alleviates hypothyroidism-induced myocardial fibrosis in rats through stimulating autophagy and inhibiting TGF-β1/Smad2 pathway

Xiong Song,Liangui Nie,Junrong Long,Junxiong Zhao,Xing Liu,Liuyang Wang,Da Liu,Sen Wang,Shengquan Liu,Jun Yang 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.1

Hypothyroidism alone can lead to myocardial fibrosis and result in heart failure, but traditional hormone replacement therapy does not improve the fibrotic situation. Hydrogen sulfide (H2S), a new gas signaling molecule, possesses antiinflammatory, antioxidant, and anti-fibrotic capabilities. Whether H2S could improve hypothyroidism-induced myocardial fibrosis are not yet studied. In our study, H2S could decrease collagen deposition in the myocardial tissue of rats caused by hypothyroidism. Furthermore, in hypothyroidism-induced rats, we found that H2S could enhance cystathionine-gamma-lyase (CSE), not cystathionine β-synthase (CBS), protein expressions. Finally, we noticed that H2S could elevate autophagy levels and inhibit the transforming growth factor-β1 (TGF-β1) signal transduction pathway. In conclusion, our experiments not only suggest that H2S could alleviate hypothyroidism- induced myocardial fibrosis by activating autophagy and suppressing TGF-β1/ SMAD family member 2 (Smad 2) signal transduction pathway, but also show that it can be used as a complementary treatment to conventional hormone therapy.

Numerical study on conjugate heat transfer in a liquid-metal-cooled pipe based on a four-equation turbulent heat transfer model

Li Xian-Wen,Su Xing-Kang,Gu Long,Wang Xiang-Yang,Fan Da-Jun 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5

Conjugate heat transfer between liquid metal and solid is a common phenomenon in a liquid-metalcooled fast reactor's fuel assembly and heat exchanger, dramatically affecting the reactor’s safety and economy. Therefore, comprehensively studying the sophisticated conjugate heat transfer in a liquidmetal-cooled fast reactor is profound. However, it has been evidenced that the traditional Simple Gradient Diffusion Hypothesis (SGDH), assuming a constant turbulent Prandtl number (Prt, usually 0.85 - 1.0), is inappropriate in the Computational Fluid Dynamics (CFD) simulations of liquid metal. In recent decades, numerous studies have been performed on the four-equation model, which is expected to improve the precision of liquid metal’s CFD simulations but has not been introduced into the conjugate heat transfer calculation between liquid metal and solid. Consequently, a four-equation model, consisting of the Abe k ε turbulence model and the Manservisi kq εq heat transfer model, is applied to study the conjugate heat transfer concerning liquid metal in the present work. To verify the numerical validity of the four-equation model used in the conjugate heat transfer simulations, we reproduce Johnson’s experiments of the liquid lead-bismuth-cooled turbulent pipe flow using the four-equation model and the traditional SGDH model. The simulation results obtained with different models are compared with the available experimental data, revealing that the relative errors of the local Nusselt number and mean heat transfer coefficient obtained with the four-equation model are considerably reduced compared with the SGDH model. Then, the thermal-hydraulic characteristics of liquid metal turbulent pipe flow obtained with the four-equation model are analyzed. Moreover, the impact of the turbulence model used in the four-equation model on overall simulation performance is investigated. At last, the effectiveness of the four-equation model in the CFD simulations of liquid sodium conjugate heat transfer is assessed. This paper mainly proves that it is feasible to use the four-equation model in the study of liquid metal conjugate heat transfer and provides a reference for the research of conjugate heat transfer in a liquidmetal-cooled fast reactor

Physical properties and chemical composition of the cores in the California molecular cloud

Zhang, Guo-Yin,Xu, Jin-Long,Vasyunin, A. I.,Semenov, D. A.,Wang, Jun-Jie,Dib, Sami,Liu, Tie,Liu, Sheng-Yuan,Zhang, Chuan-Peng,Liu, Xiao-Lan,Wang, Ke,Li, Di,Wu, Zhong-Zu,Yuan, Jing-Hua,Li, Da-Lei,Gao, Springer-Verlag 2018 Astronomy and astrophysics Vol.620 No.-

<P><I>Aims.</I> We aim to reveal the physical properties and chemical composition of the cores in the California molecular cloud (CMC), so as to better understand the initial conditions of star formation.</P><P><I>Methods.</I> We made a high-resolution column density map (18.2′′) with <I>Herschel</I> data, and extracted a complete sample of the cores in the CMC with the fellwalker algorithm. We performed new single-pointing observations of molecular lines near 90 GHz with the IRAM 30m telescope along the main filament of the CMC. In addition, we also performed a numerical modeling of chemical evolution for the cores under the physical conditions.</P><P><I>Results.</I> We extracted 300 cores, of which 33 are protostellar and 267 are starless cores. About 51% (137 of 267) of the starless cores are prestellar cores. Three cores have the potential to evolve into high-mass stars. The prestellar core mass function (CMF) can be well fit by a log-normal form. The high-mass end of the prestellar CMF shows a power-law form with an index <I>α</I> = −0.9 ± 0.1 that is shallower than that of the Galactic field stellar mass function. Combining the mass transformation efficiency (<I>ε</I>) from the prestellar core to the star of 15 ± 1% and the core formation efficiency (CFE) of 5.5%, we suggest an overall star formation efficiency of about 1% in the CMC. In the single-pointing observations with the IRAM 30m telescope, we find that 6 cores show blue-skewed profile, while 4 cores show red-skewed profile. [HCO<SUP>+</SUP>]/[HNC] and [HCO<SUP>+</SUP>]/[N2H<SUP>+</SUP>] in protostellar cores are higher than those in prestellar cores; this can be used as chemical clocks. The best-fit chemical age of the cores with line observations is ~5 × 10<SUP>4</SUP> yr.</P>

Sagittal Pelvic Radius in Low-Grade Isthmic Lumbar Spondylolisthesis of Chinese Population

Zhao, Yang,Shen, Cai-Liang,Zhang, Ren-Jie,Cheng, Da-Wei,Dong, Fu-Long,Wang, Jun The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.3

Objective : To investigate the variation of pelvic radius and related parameters in low-grade isthmic lumbar spondylolisthesis. Methods : Seventy-four patients with isthmic lumbar spondylolisthesis and 47 controls were included in this study. There were 17 males and 57 females between 30 and 66 years of age, including 30 with grade I slippages and 44 grade II slippages; diseased levels included 34 cases on L4 and 40 cases on L5. Thoracic kyphosis (TK), the pelvic radius (PR), the pelvic angle (PA), pelvic morphology (PR-S1), and total lumbopelvic lordosis (PR-T12) were assessed from radiographs. Results : Statistically significant differences were found for the PA, PR-T12, and PR-S1 ($24.5{\pm}6.6^{\circ}$, $83.7{\pm}9.8^{\circ}$, and $25.4{\pm}11.2^{\circ}$, respectively) of the patients with spondylolisthesis and the healthy volunteers ($13.7{\pm}7.8^{\circ}$, $92.9{\pm}9.2^{\circ}$, and $40.7{\pm}8.9^{\circ}$, respectively). The TK/PR-T12 ratios were between 0.15 and 0.75. However, there were no differences in all the parameters between the L4 and L5 spondylolysis subgroups (p>0.05). The TK and PR-S1 of grade II were less than grade I, but the PA was greater. The PR-T12 of female patients were less than male patients, but the PA was greater (p<0.05). Conclusion : Pelvic morphology differed in patients with low-grade isthmic lumbar spondylolisthesis compared to controls. Gender and the grade of slippage impacted the sagittal configuration of the pelvis, but the segment of the vertebral slip did not. Overall, the spine of those with spondylolisthesis remains able to maintain sagittal balance despite abnormal pelvic morphology.