Astaxanthin, Histone Deacetylase 9, and Metabolic and Inflammatory Diseases in Obesity

Siqi Hu,Hyunju Kang,Minkyung Bae,Yoojin Lee,Mi-Bo Kim,Tho Pham,Young-Ki Park,Ji-Young Lee 한국식품영양과학회 2019 한국식품영양과학회 학술대회발표집 Vol.2019 No.10

Failure Envelopes of Bucket Foundations for Offshore Wind Turbinesunder Combined Loading Including Torsion

Siqi Li,Yuan Wang,Qing-wen Li,Jing-qi Huang,Jin-hui Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.12

The loading condition of bucket foundations for offshore wind turbines is very complicated and often under combined loading, but the torsion is always ignored. So, it is necessary to investigate the failure envelopes including torsion of bucket foundations. Under the premise of validating the reliability of the numerical model by comparing with other published data, failure envelopes in each loading space are obtained and the applicability of swipe test for the determination of H-T failure envelope and M-T failure envelope of bucket foundations is explored. The impacts of torsion and aspect ratio on the combined bearing capacities are studied. While revealing the law of impacts, equations are proposed to determine the respective failure envelopes and evaluate the combined bearing capacities. The V-H-M-T failure envelope can reveal the torsion effect on envelope under traditional V-H-M loading, the results show that the normalized V-H-M failure envelopes under different torsions almost coincide, torsion effect can be easily considered according to this characteristic.

Determining Osteogenic Differentiation Efficacy of Pluripotent Stem Cells by Telomerase Activity

Siqi Zhang,Yuhua Sun,Yi Sui,Yan Li,Zuyuan Luo,Xiao Xu,Ping Zhou,Shicheng Wei 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.6

BACKGROUND: Bone tissue engineering based on pluripotent stem cells (PSCs) is a new approach to deal with bone defects. Protocols have been developed to generate osteoblasts from PSCs. However, the low efficiency of this process is still an important issue that needs to be resolved. Many studies have aimed to improve efficiency, but developing accurate methods to determine efficacy is also critical. Studies using pluripotency to estimate efficacy are rare. Telomerase is highly associated with pluripotency. METHODS: We have described a quantitative method to measure telomerase activity, telomeric repeat elongation assay based on quartz crystal microbalance (QCM). To investigate whether this method could be used to determine the efficiency of in vitro osteogenic differentiation based on pluripotency, we measured the pluripotency pattern of cultures through stemness gene expression, proliferation ability and telomerase activity, measured by QCM. RESULTS: We showed that the pluripotency pattern determined by QCM was similar to the patterns of proliferation ability and gene expression, which showed a slight upregulation at the late stages, within the context of the general downregulation tendency during differentiation. Additionally, a comprehensive gene expression pattern covering nearly every stage of differentiation was identified. CONCLUSION: Therefore, this assay may be powerful tools for determining the efficiency of differentiation systems based on pluripotency. In this study, we not only introduce a new method for determining efficiency based on pluripotency, but also provide more information about the characteristics of osteogenic differentiation which help facilitate future development of more efficient protocols.

Design and Analysis of a Plane Vibration-based Electromagnetic Generator Using a Magnetic Spring and Ferrofluid

Siqi Wang,Decai Li 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.5

This paper describes the design and characterization of a plane vibration-based electromagnetic generator that is capable of converting low-frequency vibration energy into electrical energy. A magnetic spring is formed by a magnetic attractive force between fixed and movable permanent magnets. The ferrofluid is employed on the bottom of the movable permanent magnet to suspend it and reduce the mechanical damping as a fluid lubricant. When the electromagnetic generator with a ferrofluid of 0.3 g was operated under a resonance condition, the output power reached 0.27 mW, and the power density of the electromagnetic generator was 5.68 μW/cm2. The electromagnetic generator was also used to harvest energy from human motion. The measured average load powers of the electromagnetic generator from human waist motion were 0.835 mW and 1.3 mW during walking and jogging, respectively.

Identification of drug target candidates of the swine pathogen Actinobacillus pleuropneumoniae by construction of protein–protein interaction network

Siqi Li,Zhipeng Su,Chengjun Zhang,Zhuofei Xu,Xiaoping Chang,Jiawen Zhu,Ran Xiao,Lu Li,Rui Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae has led to severe economic losses in the pig industry worldwide. A. pleuropneumoniae displays various levels of antimicrobial resistance, leading to the dire need to identify new drug targets. Protein–protein interaction (PPI) network can aid the identification of drug targets by discovering essential proteins during the life of bacteria. The aim of this study is to identify drug target candidates of A. pleuropneumoniae from essential proteins in PPI network. The homologous protein mapping method (HPM) was utilized to construct A. pleuropneumoniae PPI network. Afterwards, the subnetwork centered with H-NS was selected to verify the PPI network using bacterial two-hybrid assays. Drug target candidates were identified from the hub proteins by analyzing the topology of the network using interaction degree and homologous comparison with the pig proteome. An A. pleuropneumoniae PPI network containing 2737 non-redundant interaction pairs among 533 proteins was constructed. These proteins were distributed in 21 COG functional categories and 28 KEGG metabolic pathways. The A. pleuropneumoniae PPI network was scale free and the similar topological tendencies were found when compared with other bacteria PPI network. Furthermore, 56.3% of the H-NS subnetwork interactions were validated. 57 highly connected proteins (hub proteins) were identified from the A. pleuropneumoniae PPI network. Finally, 9 potential drug targets were identified from the hub proteins, with no homologs in swine. This study provides drug target candidates, which are promising for further investigations to explore lead compounds against A. pleuropneumoniae.

Batch Fabrication and Characterization of ZnO/PLGA/PCL Nanofiber Membranes for Antibacterial Materials

Siqi Li,Jing Yin,Lan Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

As biomaterials with excellent biocompatibility, biodegradation and low toxicity, poly(ε-caprolactone) (PCL) andpoly(lactic-co-glycolic acid) (PLGA) are extensively applied as wound dressing and surgical suture in biomedical field. Inthis paper, an oblique section free surface electrospinning (OSFSE) apparatus was utilized to prepare high-quality and highoutputZnO/PLGA/PCL nanofiber membranes (NFMs) for antibacterial materials, which could significantly increase theproduction of ZnO/PLGA/PCL NFMs from 0.01-0.1 g/h of traditional electrospinning to 30.84 g/h of OSFSE. The influencesof the weight proportion of PLGA and PCL on the viscosity and conductivity of electrospinning solutions along with theyield, morphology and wettability of PLGA/PCL NFMs were researched, and the optimum weight ratio of 6:4 wasdetermined. Then the effects of ZnO contents on the electrospinning solution properties as well as the yield, morphology,structure, wettability, mechanical property and antibacterial performance of ZnO/PLGA/PCL NFMs with the optimal ratio ofPLGA and PCL were studied. The results illustrated that additive nano-ZnO could improve markedly the antibacterial effectof NFMs, and the NFMs with 3 wt% nano-ZnO had excellent antibacterial effect on Escherichia coli (95.3 %) andStaphylococcus aureus (95.7 %).

Comparison of Endocrine Therapies in Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Negative Locally Advanced or Metastatic Breast Cancer: A Network Meta-Analysis

Siqi Liu,Xin Sun,Xiaohui Xu,Fangcai Lin 한국유방암학회 2020 Journal of breast cancer Vol.23 No.5

We aimed to explore what kind of endocrine treatments are optimal for hormone receptor-positive and human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer in some specific clinical situations. We searched randomized controlled trials in Embase, Medline, the Cochrane library, and PubMed from inception to April 1, 2020 and performed a network meta-analysis based on a Bayesian fixed-effects model. Progression-free survival (PFS) with hazard ratios and corresponding 95% confidence interval was defined as the primary endpoint, while overall survival (OS), objective response rate (ORR), clinical benefit rate and serious adverse events were used as secondary endpoints. A total of 35 studies involving 12,285 patients and 24 treatment options were included. In general, most co-treatment options prolonged PFS compared to single-agent therapy, of which aromatase inhibitor (AI) plus everolimus and fulvestrant plus palbociclib were probably the most effective agents, and the latter had the best safety record. However, despite the superior efficacy of fulvestrant plus capecitabine for PFS and OS, palpable toxic effects have been demonstrated for this treatment, so its application must be scrupulously considered. The results of subgroup analysis indicated that fulvestrant combined with palbociclib improved prognosis for phosphatidylinositol 3-kinase (PI3K)-mutated patients, PI3K-unmutated patients, patients with endocrine therapy resistance, and visceral metastatic patients, while no obvious improvement was detected in OS. Moreover, the efficacy of fulvestrant plus cyclin-dependent kinase 4/6 (CDK4/6) inhibitors was slightly better than that of AI plus CDK4/6 inhibitors, while AI plus everolimus was more efficacious than fulvestrant combined with everolimus in terms of PFS, OS, and ORR. In conclusion, our results provide moderate evidence that fulvestrant plus palbociclib and AI plus everolimus were the most effective treatments, while the efficacy and safety of fulvestrant plus palbociclib was obviously superior in some specific clinical situations.

Effect of aberrantly methylated androgen receptor target gene PCDH7 on the development of androgen-independent prostate cancer cells

Siqi Xu,Xiaoyan Wu,Zhihua Tao,Hongsheng Li1,Chenliang Fan,Songjin Chen,Jianwei Guo,Yao Ning,Xuqi Hu 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Androgen-independent prostate cancer (AIPC) is an extremely malignant tumor developed from the androgen dependent (ADPC). However, the mechanism of transition process from ADPC to AIPC remains unknown. Objective Here we aimed to identify the androgen receptor (AR) target gene and its roles in AIPC. Methods Target genes of AR were identified by ChIP-seq in AIPC cells. AR target gene PCDH7 was detected by real time PCR and western blot. Methylation of PCDH7 was measured by bisulfite sequencing and bisulfite amplicon sequencing. Cell growth, invasion and apoptosis were measured by CCK-8, transwell and flow cytometry, respectively. Results AR was significantly enriched in the upstream of PCDH7 gene. The expression of PCDH7 was significantly decreased, while the methylation of PCDH7 was increased in the AIPC cells compared to the ADPC cells. DNA methyltransferase inhibitor significantly suppressed the methylation and increased the mRNA and protein level of PCDH7. Moreover, overexpression of DNMT1 remarkably reduced the mRNA and protein level of PCDH7. DNA methyltransferase inhibitor decreased the cell growth and invasion while promote the cell apoptosis in the AIPC cells. AR significantly target PCDH7, whose hypermethylation may repress cell growth and invasion, and promote apoptosis in AIPC. Conclusions This study might provide a novel potential target for the treatment of AIPC.

Histone Deacetylase 9: Its Role in the Pathogenesis of Diabetes and Other Chronic Diseases

Siqi Hu,조은희,이지영 대한당뇨병학회 2020 Diabetes and Metabolism Journal Vol.44 No.2

As a member of the class IIa histone deacetylases (HDACs), HDAC9 catalyzes the deacetylation of histones and transcription factors, commonly leading to the suppression of gene transcription. The activity of HDAC9 is regulated transcriptionally and posttranslationally. HDAC9 is known to play an essential role in regulating myocyte and adipocyte differentiation and cardiac muscle development. Also, recent studies have suggested that HDAC9 is involved in the pathogenesis of chronic diseases, including cardiovascular diseases, osteoporosis, autoimmune disease, cancer, obesity, insulin resistance, and liver fibrosis. HDAC9 modulates the expression of genes related to the pathogenesis of chronic diseases by altering chromatin structure in their promotor region or reducing the transcriptional activity of their respective transcription factors. This review summarizes the current knowledge of the regulation of HDAC9 expression and activity. Also, the roles of HDAC9 in the pathogenesis of chronic diseases are discussed, along with potential underlying mechanisms.

Non-square colour image scrambling based on two-dimensional Sine-Logistic and Henon map

( Siqi Zhou ),( Feng Xu ),( Ping Ping ),( Zaipeng Xie ),( Xin Lyu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.12

Image scrambling is an important technology in information hiding, where the Arnold transformation is widely used. Several researchers have proposed the application of Henon map in square image scrambling, and certain improved technologies require scrambling many times to achieve a good effect without resisting chosen-plaintext attack although it can be directly applied to non-square images. This paper presents a non-square image scrambling algorithm, which can resist chosen-plaintext attack based on a chaotic two-dimensional Sine Logistic modulation map and Henon map (2D-SLHM). Theoretical analysis and experimental results show that the proposed algorithm has advantages in terms of key space, efficiency, scrambling degree, ability of anti-attack and robustness to noise interference.