Simulation of porous claddings using LES and URANS: A 5:1 rectangular cylinder

Mao Xu,Luca Patruno,Yuan-Lung Lo,Stefano de Miranda,Francesco Ubertini 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.35 No.1

While the aerodynamics of solid bluff bodies is reasonably well-understood and methodologies for their reliable numerical simulation are available, the aerodynamics of porous bluff bodies formed by assembling perforated plates has received less attention. The topic is nevertheless of great technical interest, due to their ubiquitous presence in applications (fences, windbreaks and double skin facades to name a few). This work follows previous investigations by the authors, aimed at verifying the consistency of numerical simulations based on the explicit modelling of the perforated plates geometry and their representation by means of pressure-jumps. In this work we further expand such investigations and, contextually, we provide insight into the flow arrangement and its sensitivity to important modelling and setup configurations. To this purpose, Unsteady Reynolds-Averaged Navier-Stokes (URANS) and Large-Eddy Simulations (LES) are performed for a 5:1 rectangular cylinder at null angle of attack. Then, using URANS, porosity and attack angle are simultaneously varied. To the authors' knowledge this is the first time in which LES are used to model a porous bluff body and compare results obtained using the explicit modelling approach to those obtained relying on pressure-jumps. Despite the flow organization often shows noticeable differences, good agreement is found between the two modelling strategies in terms of drag force.

On the numerical simulation of perforated bluff-bodies: A CFD study on a hollow porous 5:1 rectangular cylinder

Mao Xu,Luca Patruno,Yuan-Lung Lo,Stefano de Miranda,Francesco Ubertini 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.1

In this work the flow through a hollow porous 5:1 rectangular cylinder made of perforated plates is numerically investigated by means of 2D URANS based simulations. Two approaches are adopted to account for the porous surfaces: in the first one the pores are explicitly modeled, so providing a detailed representation of the flow. In the second one, the porous surfaces are modeled by means of pressure jumps, which allow to take into account the presence of pores without reproducing the flow details. Results obtained by using the two aforementioned techniques are compared aiming at evaluating differences and similarities, as well as identifying the main flow features which might cause discrepancies. Results show that, even in the case of pores remarkably smaller than the immersed body, their arrangement can lead to local mechanisms able to affect the global flow arrangement, so limiting the accuracy of pressure jumps based simulations. Despite that, time-averaged fields often show a reasonable agreement between the two approaches.

Localization and Privacy Preservation in Cognitive Radio Networks

Xu Zhang,Xia Ying,Hongrui Mao,Hae Young Bae 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

Cognitive Radio Networks (CRNs) has been considered as a key technology for future wireless communications and mobile computing. Localization of primary user is crucial in enabling several key capabilities in CRNs. In this paper, we present a survey of representative methods dealing with user localization and location privacy preservation issues and propose a taxonomy that summarizes the state-of-the-art. The objective is to provide a comprehensive analysis and guide of existing efforts around localization and location privacy preservation in cognitive radio network. This survey is intended to help researchers in quickly understanding existing works and challenges, and possible improvements to bring.

Circular RNA CREBBP modulates cartilage degradation by activating the Smad1/5 pathway through the TGFβ2/ALK1 axis

Xu Yiyang,Mao Guping,Long Dianbo,Deng Zengfa,Xin Ruobin,Zhang Ziji,Xue Ting,Liao Weiming,Xu Jie,Kang Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Osteoarthritis, characterized by articular cartilage degradation, is the leading cause of chronic disability in older adults. Studies have indicated that circular RNAs are crucial regulators of chondrocyte development and are involved in the progression of osteoarthritis. In this study, we investigated the function and mechanism of a circular RNA and its potential for osteoarthritis therapy. The expression levels of circCREBBP, screened by circular RNA sequencing during chondrogenic differentiation in adipose tissue-derived stem cells, and TGFβ2 were significantly increased in the cartilage of patients with osteoarthritis and IL-1β-induced chondrocytes. circCREBBP knockdown increased anabolism in the extracellular matrix and inhibited chondrocyte degeneration, whereas circCREBBP overexpression led to the opposite effects. Luciferase reporter assays, rescue experiments, RNA immunoprecipitation, and RNA pulldown assays confirmed that circCREBBP upregulated TGFβ2 expression by sponging miR-1208, resulting in significantly enhanced phosphorylation of Smad1/5 in chondrocytes. Moreover, intra-articular injection of adeno-associated virus-sh-circCrebbp alleviated osteoarthritis in a mouse model of destabilization of the medial meniscus. Our findings reveal a critical role for circCREBBP in the progression of osteoarthritis and provide a potential target for osteoarthritis therapy.

Surgical treatment for hepatocellular carcinoma with bile duct invasion

Xu-guang Hu,Wei Mao,Sung Yeon Hong,Bong-Wan Kim,Wei-guang Xu,Hee-Jung Wang 대한외과학회 2016 Annals of Surgical Treatment and Research(ASRT) Vol.90 No.3

Purpose: There is still some debate on surgical procedures for hepatocellular carcinoma (HCC) patients with bile duct tumor thrombi (BDTT, Ueda type 3 or 4). What is adequate extent of liver resection for curative treatment? Is extrahepatic bile duct resection mandatory for cure? The aim of this study is to answer these questions. Methods: Between February 1994 and December 2012, 877 consecutive HCC patients underwent hepatic resection at Ajou University Hospital. Thirty HCC patients (3.4%) with BDTT (Ueda type 3 or 4) were retrospective reviewed in this study. Results: In total, 20 patients enrolled in this study were divided into 2 groups: patients who underwent hemihepatectomy with extrahepatic bile duct resection (group 1, n = 10) and with only removal of BDTT (group 2, n = 10). The 1-, 3- and 5-year overall survival rates were 75.0%, 50.0%, and 27.8%, respectively. The 1-, 3-, and 5-year survival rates of group 1 were 100.0%, 80.0%, and 45.7%, and those of group 2 were 50.0%, 20.0%, and 10.0%, respectively (P = 0.014). The 1-, 3-, and 5-year recurrences free survival rates of group 1 were 90.0%, 70.0%, and 42.0%, and those of group 2 were 36.0%, 36.0%, and 0%, respectively (P = 0.014). Thrombectomy and infiltrative growth type (Ig) were found as independent prognostic factors for recurrence free survival by multivariate analysis. Thrombectomy, Ig, and high indocyanine green retention rate at 15 minutes were found as independent prognostic factors for overall survival by multivariate analysis. Conclusion: We suggest that the appropriate surgical procedure for icteric HCC patients should be comprised of ipsilateral hemihepatectomy with caudate lobectomy and extrahepatic bile duct resection.

Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements

Mao Xu,Kazuhide Matsuda 한국대기환경학회 2020 Asian Journal of Atmospheric Environment (AJAE) Vol.14 No.4

The atmospheric nitrogen compounds can serve as a nutrient; however, its excess deposition has harmful effects on terrestrial ecosystems due to acidification and eutrophication. There are still large uncertainties concerning the dry deposition process of PM2.5 nitrate in forests, even though this process affects the accuracy of chemical transport model simulations. To better understand this process, we conducted vertical profile measurements of inorganic ions in PM2.5 and SO2 above and within a forest canopy in the Field Museum Tamakyuryo site in suburban Tokyo with a particular focus on the processes observed under both daytime and nighttime and both leafy and leafless conditions. We performed two observations during leafy periods (July 21-August 1, 2015, and September 27-October 11, 2016) and one observation during a leafless period (February 23-29, 2016). To obtain daytime and nighttime vertical profiles, we set filter holders at 4 or 5 heights on an observation tower in the forest and changed the filters for each daytime and nighttime. For the PM2.5, the vertical gradients of NO3- concentration were larger than those of SO42- during both the daytime and nighttime for all observational periods, particularly during the leafy periods. In addition, the decreasing rate of NO3- in the PM2.5 within the canopy was larger than that of SO2 for some observational periods. In the daytime, the air temperature was higher near the canopy surface during the leafy period and near the ground surface during the leafless period. As also suggested by past studies, the large gradients of NO3 - in the PM2.5 during the leafy period were likely caused by the volatilization of NH4NO3 near the deposition surfaces due to the higher temperature in the daytime and the lower concentration of HNO3 caused by its fast removal during both the daytime and nighttime.

Luciferase Assay to Screen Tumour-specific Promoters in Lung Cancer

Xu, Rong,Guo, Long-Jiang,Xin, Jun,Li, Wen-Mao,Gao, Yan,Zheng, You-Xian,Guo, You-Hong,Lin, Yang-Jun,Xie, Yong-Hua,Wu, Ya-Qing,Xu, Rui-An Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Objective: Specific promoters could improve efficiency and ensure the safety of gene therapy. The aim of our study was to screen examples for lung cancer. Methods: The firefly luciferase gene was used as a reporter, and promoters based on serum markers of lung cancer were cloned. The activity and specificity of seven promoters, comprising CEACAM5 (carcinoembryonic antigen, CEA), GRP (Gastrin-Releasing Peptide), KRT19 (cytokeratin 19, KRT), SFTPB (surfactant protein B, SP-B), SERPINB3 (Squamous Cell Carcinoma Antigen, SCCA), SELP (Selectin P, Granule Membrane Protein 140kDa, Antigen CD62, GMP) and DKK1 (Dickkopf-1) promoters were compared in lung cancer cells to obtain cancer-specific examples with strong activity. Results: The CEACAM5, DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB promoters were cloned. Furthermore, we successfully constructed recombinant vector pGL-CEACAM5 (DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB) contained the target gene. After cells were transfectedwith recombinant plasmids, we found that the order of promoter activity from high to low was SERPINB3, DKK1, SFTPB, KRT19, CEACAM5, SELP and GRP and the order for promoters regarding specificity and high potential were SERPINB3, DKK1, SELP, SFTPB, CEACAM5, KRT19 and GRP. Conclusion: The approach adopted is feasible to screen for new tumour specific promoters with biomarkers. In addition, the screened lung-specific promoters might have potential for use in lung cancer targeted gene therapy research.

Prostate Cancer Risk in Relation to a Single Nucleotide Polymorphism in the Insulin-like Growth Factor-binding Protein-3 (IGFBP3) Gene: a Meta-analysis

Mao, Ye-Qing,Xu, Xin,Lin, Yi-Wei,Chen, Hong,Hu, Zheng-Hui,Xu, Xiang-Lai,Zhu, Yi,Wu, Jian,Zheng, Xiang-Yi,Qin, Jie,Xie, Li-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Insulin-like growth factor-binding protein-3 (IGFBP3) has been identified as a putative tumor suppressor with multifunctional roles in the IGF axis. Recently, there have been a growing body of studies investigating the relation between the IGFBP3 A-202C polymorphism, circulating IGFBP3 and prostate cancer risk, but their outcomes varied leading to controversy. Hence, it is necessary to perform a meta-analysis covering all eligible studies to shed a light on the association of IGFBP3 A-202C and cancer risk. Finally, we included a total of 11 relevant articles between 2003 and 2010 covering 14 case-control studies including 9,238 cases and 8,741 controls for our analysis. Our results showed that A-202C was a marginal risk factor of prostate cancer (allele contrast: OR=1.08, 95% CI :1.01-1.16; dominant model: OR=1.11, 95% CI :1.01-1.22; heterozygote codominant model: OR=1.11, 95% CI :1.03-1.18; homozygote contrast: OR=1.19, 95% CI :1.03-1.37). Stratification analysis revealed that sample size and control source were two major heterogeneous meta-factors especially in the recessive model (source: Population-based control group :p=0.30,I2=16.7%, Hospital-based control group: p=0.20, I2=30.3%; sample size: Small: p=0.22,I2= 32.8%, Medium: p=0.09,I2=48%, Large p=0.60,I2=0.0%); However, contrary to previous findings, no significance was found in racial subgroups. No significant publication bias was found in our analysis. Considering the robustness of the results and the discrepancy among some studies, there might be some unsolved confounding factors, and further more critical large studies are needed for confirmation.

MicroRNA-409-3p Inhibits Migration and Invasion of Bladder Cancer Cells via Targeting c-Met

Xin Xu,Liping Xie,Hong Chen,Yiwei Lin,Zhenghui Hu,Yeqing Mao,Jian Wu,Xianglai Xu,Yi Zhu,Shiqi Li,Xiangyi Zheng 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.1

There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may con-tribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.

Neutropenia during the First Cycle of Induction Chemotherapy Is Prognostic for Poor Survival in Locoregionally Advanced Nasopharyngeal Carcinoma: A Real-World Study in an Endemic Area

Cheng Xu,Shi-Ping Yang,Yuan Zhang,Ling-Long Tang,Guan-Qun Zhou,Xu Liu,Yan-Ping Mao,Rui Guo,Wen-Fei Li,Lei Chen,Ai-Hua Lin,Ying Sun,Jun Ma 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose The purpose of this study was to investigate the effect of neutropenia during the first cycle of induction chemotherapy (IC-1) on survival in locoregionally advanced nasopharyngeal carcinoma (LANPC). Materials and Methods Eligible patients (n=545) with LANPC receiving IC+concurrent chemoradiotherapy were included. Based on nadir neutrophil after IC-1, all patients were categorized into three groups: no/grade 1-2/grade 3-4 neutropenia. Five-year overall survival (OS) and disease-free survival (DFS) were compared between groups and subgroups stratified by IC regimen. We also explored the occurrence of IC-1–induced myelosuppression events and the minimal value of post-treatment neutrophil-to-lymphocyte ratio (post-NLRmin). Univariate/multivariate analyses were performed to investigate the effect of IC-1–induced neutropenia, timing of neutropenia, number of myelosuppression events, and high post-NLRmin on OS/DFS. Results Grade 1-2/grade 3-4 neutropenia were associated with poorer OS/DFS than no neutropenia (all p < 0.05); OS/DFS were not significantly different between patients experiencing grade 1-2 vs. 3-4 neutropenia. Neutropenia had no significant effect on OS/DFS in patients receiving docetaxel–cisplatin–5-fluorouracil (TPF). Grade 1-2 (grade 3-4) neutropenia negatively influenced OS/DFS in patients receiving cisplatin–5-fluorouracil (PF) (PF and docetaxel– cisplatin [TP]; all p < 0.05). Neutropenia, two/three myelosuppression events, and high post-NLRmin ( 1.33) was most frequent on days 5-10, second and third week of IC-1, respectively. After adjustment for covariates, IC-1–induced neutropenia, two/three myelosuppression events, and post-NLRmin  1.33 were validated as negative predictors of OS/DFS (all p < 0.05); timing of neutropenia had no significant effect. Conclusion Occurrence of neutropenia, number of myelosuppression events, and high post-NLRmin during PF/TP IC-1 have prognostic value for poor survival in LANPC.