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Development of a High-Speed and Precision Micro- Spindle for Micro-Cutting
Wei Liu,Zhixiong Zhou,Xiangming Huang,Zhi-Jian He,Yong Du 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.
Mechanical micromachining using micro-machine tools is very competitive in manufacturing geometrically complex 3D micro-partsin various engineering materials with advantages of small space, energy-efficient, low equipment production and operation costs. Askey components of micro-machine tools, micro-spindles directly determine the performance of micro-machine tools and theapplication and development of mechanical micromachining technology. This study proposes a novel design concept of the separatelyspindle and tool and one-piece tool/rotor structure for micro-spindles, whose micro-tool can maintain good rotational accuracy athigh rotational speeds. In the principle prototype micro-spindle, an air driven turbine was used as power spindle. The design andoptimization of the micro-spindle were conducted. The fabrication and evaluation of the prototype micro-spindle were presented. Theresults of the principle prototype micro-spindle were analyzed and some efforts for the subsequent micro-spindle were proposed.
Chemical Constituents from the Aerial Parts of Isodon coetsa and their Cytotoxicity
Wei Zhao,Jian Xin Pu,Xue Du,Yong Zhao,Fei He,Hai Bo Zhang,Yong Bo Xue,Wei Lie Xiao,Han Dong Sun,Ying Li Wu,Guo Qiang Chen 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.12
Three new compounds (1-3), including a neolignan, a triterpenoid, and a diterpenoid, together with twenty known compounds (4-23), were isolated from the aerial parts of Isodon coetsa. Their structures and relative configurations were elucidated on the basis of spectroscopic data. Compounds 1, 3, 5-9, 11-13, 16-17, and 19-23 were evaluated for their cytotoxicity against HT-29, BEL-7402, and SK-OV-3 human tumor cell lines. Compound 7 showed significant inhibitory effects on all three types of cells, with IC50 values of 2.52, 3.06, 2.14 μM, respectively.
Wei, Guo,Nie, Ming-Ming,Shen, Xiao-Jun,Xue, Xu-Chao,Ma, Li-Ye,Du, Cheng-Hui,Wang, Shi-Liang,Bi, Jian-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1
Objective: To observe local and systemic toxicity after sustained-release 5-fluorouracil (5-Fu) implantation in canine peritoneum and para-aortic abdominalis and the changes of drug concentration in the local implanted tissue with time. Methods: 300 mg sustained-release 5-Fu was implanted into canine peritoneum and para-aorta abdominalis. Samples were taken 3, 5, 7 and 10 days after implantation for assessment of changes and systemic reactions. High performance liquid chromatography was applied to detect the drug concentrations of peritoneal tissue at different distances from the implanted site, lymphatic tissue of para-aortic abdominalis, peripheral blood and portal venous blood. Results: 10 days after implantation, the drug concentrations in the peritoneum, lymphatic tissue and portal vein remained relatively high within 5 cm of the implanted site. There appeared inflammatory reaction in the local implanted tissue, but no visible pathological changes such as cell degeneration and necrosis, and systemic reaction like anorexia, nausea, vomiting and fever. Conclusions: Sustained-release 5-Fu implantation in canine peritoneum and para-aortic abdominalis can maintain a relatively high tumour-inhibiting concentration for a longer time in the local implanted area and portal vein, and has mild local and systemic reactions. Besides, it is safe and effective to prevent or treat recurrence of gastrointestinal tumours and liver metastasis.
Synthesis of S-adenosyl-L-methionine in Escherichia coli
Xiao-Nan Wei,Minjie Cao,Jian Li,Huan Li,Yi Song,Cuihong Du 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.6
S-adenosyl-L-methionine (SAM) is an importantphysiological metabolite in vivo and may be useful inmedicines. SAM is produced from L-methionine and ATPcatalyzed by S-adenosyl-L-methionine synthetase (SAMS)in vivo. In this study, the gene encoding SAMS was clonedand a genetically engineered Escherichia coli (E. coli)BL21(pET-28a-SAMS) was constructed. The recombinantSAMS with a molecular mass of approximately 46 kDawas expressed by inducing the engineered E. coli usingisopropyl-β-D-1-thiogalactopyranoside (IPTG) as an inducer. To produce SAM using a low-cost, nontoxic and highperformanceexpression system, lactose was used as asubstitute for IPTG to induce BL21(pET-28a-SAMS). Byoptimizing the expression conditions, the concentration ofSAM produced by the engineered E. coli was 48 mg/L in theculture medium supernatant. To increase the concentrationof SAM produced, a coupled system was constructedconsisting of E. coli BL21(pET-28a-SAMS) and Saccharomycescerevisiae (S. cerevisiae) JM-310. In this coupled system,ATP generated from S. cerevisiae was provided to E. colifor producing a higher concentration of SAM. The SAMconcentration in the coupled system reached 1.7 g/L. SAMwas purified by a weak acid cationic exchange resin D113,and a simple and economical purification procedure forSAM isolation was achieved. SAM was confirmed byHigh Performance Liquid Chromatography-tandem MassSpectrometry analysis. Our study provides a feasible andconvenient approach to produce SAM.
Exosomes derived from miR-214-3p overexpressing mesenchymal stem cells promote myocardial repair
Wenwu Zhu,Qingjie Wang,Jian Zhang,Ling Sun,Xiu Hong,Wei Du,Rui Duan,Jianguang Jiang,Yuan Ji,Haoran Wang,Bing Han 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00
Aims Exosomes are known as nanovesicles that are naturally secreted, playing an essential role in stem-mediated cardioprotection. This study mainly focused on investigating if exosomes derived from miR-214 overexpressing mesenchymal stem cells (MSCs) show more valid cardioprotective ability in a rat model of acute myocardial infarction (AMI) and its potential mechanisms. Methods Exosomes were isolated from control MSCs (Ctrl-Exo) and miR-214 overexpressing MSCs (miR-214OE-Exo) and then they were delivered to cardiomyocytes and endothelial cells in vitro under hypoxia and serum deprivation (H/SD) condition or in vivo in an acutely infarcted Sprague-Dawley rat heart. Regulated genes and signal pathways by miR-214OE-Exo treatment were explored using western blot analysis and luciferase assay. Results in vitro , miR-214OE-Exo enhanced migration, tube-like formation in endothelial cells. In addition, miR-214OE-Exo ameliorated the survival of cardiomyocytes under H/SD. In the rat AMI model, compared to Ctrl-Exo, miR-214OE-Exo reduced myocardial apoptosis, and therefore reduced infarct size and improved cardiac function. Besides, miR-214OE-Exo accelerated angiogenesis in peri-infarct region. Mechanistically, we identified that exosomal miR-214-3p promoted cardiac repair via targeting PTEN and activating p-AKT signal pathway. Conclusion Exosomes derived from miR-214 overexpressing MSCs have greatly strengthened the therapeutic efficacy for treatment of AMI by promoting cardiomyocyte survival and endothelial cell function.
The Lymphotoxin-α 252 A>G Polymorphism and Breast Cancer: A Meta-analysis
Zhou, Ping,Huang, Wei,Chu, Xing,Du, Liang-Feng,Li, Jian-Ping,Zhang, Chun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5
Objective: The aim of this meta-analysis is to evaluate associations between LTA-252 A>G and breast cancer (BC). Methods: Electronic searches of several databases were conducted for all online publications. A total of 7 studies involving 4,625 BC patients and 4,373 controls were identified. Results: This meta-analysis showed no significant association between the LTA-252 A>G polymorphism and BC in overall or Caucasian populations. However, a positive association was found limited to Asian populations. Conclusion: Although there was no significant association found between the LTA-252 A>G polymorphism and BC overall, a positive association was found in Asian populations.
Wu, Bing-Li,Luo, Lie-Wei,Li, Chun-Quan,Xie, Jian-Jun,Du, Ze-Peng,Wu, Jian-Yi,Zhang, Pi-Xian,Xu, Li-Yan,Li, En-Min Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12
Background: Fascin, an actin-bundling protein forming actin bundles including filopodia and stress fibers, is overexpressed in multiple human epithelial cancers including esophageal squamous cell carcinoma (ESCC). Previously we conducted a microarray experiment to analyze fascin knockdown by RNAi in ESCC. Method: In this study, the differentially expressed genes from mRNA expression profilomg of fascin knockdown were analyzed by multiple bioinformatics methods for a comprehensive understanding of the role of fascin. Results: Gene Ontology enrichment found terms associated with cytoskeleton organization, including cell adhesion, actin filament binding and actin cytoskeleton, which might be related to fascin function. Except GO categories, the differentially expressed genes were annotated by 45 functional categories from the Functional Annotation Chart of DAVID. Subpathway analysis showed thirty-nine pathways were disturbed by the differentially expressed genes, providing more detailed information than traditional pathway enrichment analysis. Two subpathways derivated from regulation of the actin cytoskeleton were shown. Promoter analysis results indicated distinguishing sequence patterns and transcription factors in response to the co-expression of downregulated or upregulated differentially expressed genes. MNB1A, c-ETS, GATA2 and Prrx2 potentially regulate the transcription of the downregulated gene set, while Arnt-Ahr, ZNF42, Ubx and TCF11-MafG might co-regulate the upregulated genes. Conclusions: This multiple bioinformatic analysis helps provide a comprehensive understanding of the roles of fascin after its knockdown in ESCC.
Three New 11,20-Epoxy-ent-kauranoids from Isodon rubescens
Xu Liu,Ji Zhou Wu,Rui Zhan,Wei Guang Wang,Xue Du,Yan Li,Peng Zhang,Jian Xin Pu,Han Dong Sun 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12
Three rare and new 11,20-epoxy-ent-kaurane diterpenoids, named jianshirubesins D-F (1-3), along with one known analogue (4), were isolated from the aerial parts of Isodon rubescens. Their structures were established by analysis of spectroscopic data. Found in the MTT assay to evaluate the cytotoxicity of compounds 1, 2, and 4, only 1 could selectively inhibit certain cell lines from proliferating. In addition, a simple structure-activity relationship discussion might suggest a new bioactive moiety, different from the α,β-unsaturated ketone group.