Micro/nano Mechanical Machining Technique Based on the Normal Force Control

Yong-Da Yan 한국생산제조학회 2018 한국생산제조시스템학회 학술발표대회 논문집 Vol.2018 No.10

Polymer Nanostructured Components Machined Directly by the Atomic Force Microscopy Scratching Method

Yong Da Yan,Da Wei Gao,Zhen Jiang Hu,Xue Sen Zhao,Jiu Chun Yan 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

This study aims to machine complex three dimensional nano-structures on polymer surfaces directly using the Atomic Force Microscopy (AFM)-based nano-mechanical processing method. Processing parameters including the normal load, the feed rate, the machining speed and the scanning direction are optimized by the Taguchi method. Their effects on the machined depth and the surface roughness of the machined structures are analyzed. Meanwhile, the AFM PZT tube is controlled to achieve the tip’s three-dimensional motions in space. Using the optimized processing parameters, three-dimensional nanostructures on the surface of PMMA are directly fabricated. It is a novel low-cost manufacturing method for machining complex three-dimensional nano-structures or nano parts on polymer surfaces directly.

Molecular dynamics simulation of tensile behavior of diffusion bonded Ni/Al nanowires

Zhenjiang Hu,Junjie Zhang,Yong Da Yan,Jiuchun Yan,Tao Sun,김동철,강성원 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.1

Interfaces play key roles in determining mechanical properties of materials. In current work we perform molecular dynamics simulations of diffusion bonding to evaluate the effect of temperature on the morphology of the Ni/Al interface and the strength of the diffusion bonded Ni/Al nanowires. The centro-symmetry parameter is adopted to identify defect atoms generated. Simulation results show that the thickness of the Ni/Al interface has strong dependence on the temperature of diffusion bonding. Following uniaxial tension tests indicate that the yield strength of Ni/Al nanowires is smaller than both the single crystalline Ni and Al nanowires, because of the Ni/Al interface acting as dislocation source and the mobilization of pre-existing dislocations at high temperature. It is shown that the mechanical properties of diffusion bonded Ni/Al nanowires strongly depend on the temperature.

Nonviral delivery systems for antisense oligonucleotide therapeutics

Si Huang,Xin-Yan Hao,Yong-Jiang Li,Jun-Yong Wu,Da-Xiong Xiang,Shilin Luo 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Antisense oligonucleotides (ASOs) are an important tool for the treatment of many genetic disorders. However, similar to other gene drugs, vectors are often required to protect them from degradation and clearance, and to accomplish their transport in vivo. Compared with viral vectors, artificial nonviral nanoparticles have a variety of design, synthesis, and formulation possibilities that can be selected to accomplish protection and delivery for specific applications, and they have served critical therapeutic purposes in animal model research and clinical applications, allowing safe and efficient gene delivery processes into the target cells. We believe that as new ASO drugs develop, the exploration for corresponding nonviral vectors is inevitable. Intensive development of nonviral vectors with improved delivery strategies based on specific targets can continue to expand the value of ASO therapeutic approaches. Here, we provide an overview of current nonviral delivery strategies, including ASOs modifications, action mechanisms, and multi-carrier methods, which aim to address the irreplaceable role of nonviral vectors in the progressive development of ASOs delivery.

Keratin/PEO/hydroxyapatite Nanofiber Membrane with Improved Mechanical Property for Potential Burn Dressing Application

Jie Fan,Tong-da Lei,Meng-Yan Yu,Yong-Heng Wang,Fu-Yuan Cao,Qingqi Yang,Faming Tian,Yong Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

Keratin, as a promising substitute for tissue engineering due to its excellent biocompatibility and bioactivity, is used to combine one or more other polymers together. However, compound nanofibers with high keratin content (normally>90 wt.%) may result in the poor elongation of nanofiber membranes such as wound dressing. In this work, different ratios of hydroxyapatites (HA) modified by sodium hexametaphosphate were blended with keratin/polyethylene oxide (PEO) spinning solution to produce reinforced keratin blend nanofiber nonwoven membranes as a potential candidate wound dressing. The tensile strength of keratin blend nanofiber membrane with 15 % modified HA addition was two times higher than that without HA. The morphologies and chemical structure of keratin/PEO/HA nanofiber membranes were investigated using SEM, FTIR, and TG. The biocompatibility and the burn repairing performance of keratin/PEO/HA nanofiber mat were also investigated by cell culture and animal burn model. The results showed that the Keratin/PEO/HA nanofiber membranewas beneficial to enhance the proliferation of L929 cell, exhibiting an advantages in reducing inflammatory response in the infective stage and enhancing skin repairing process in the following recover stages. Our data suggested that keratin/PEO/HA nanofiber membrane could serve as a promising burn dressing for treatment of the skin burn.

A novel panel of serum miR-21/miR-155/miR-365 as a potential diagnostic biomarker for breast cancer

Ji-Guang Han,Yong-Dong Jiang,Chun-Hui Zhang,Yan-Mei Yang,Da Pang,Yan-Ni Song,Guo-Qiang Zhang 대한외과학회 2017 Annals of Surgical Treatment and Research(ASRT) Vol.92 No.2

Purpose: Insufficient sensitivity and specificity prevent the use of most existing biomarkers for early detection of breast cancer. Recently, it was reported that serum microRNAs (miRNAs) may be potential biomarkers in many cancer diseases. In this study, we investigated whether serum levels of 5 miRNAs including miR-21, miR-125b, miR-145, miR-155, and miR-365 could discriminate breast cancer patients and healthy controls. Methods: Serum levels of miRNAs were measured by using quantitative real-time polymerase chain reaction in 99 breast cancer patients and 21 healthy controls. The abundance change of serum miRNAs were also evaluated following surgical resection in 20 breast cancer patients. Receiver operating characteristic (ROC) curve analysis was performed to assess the sensitivity and specificity of miRNAs as diagnostic biomarkers. Results: Serum levels of miR-21 and miR-155 was significantly higher, while miR-365 was significantly lower in breast cancer as compared with healthy controls. The serum levels of miR-21 and miR-155 significantly decreased following surgical resection. Additionally, the serum level of miR-155 at stages I and II was significantly higher compared to stage III. The serum miR-145 level was remarkably higher in progesterone receptor (PR)-positive patients than PR-negative. The positivity of miR-21, miR-155, and miR-365 was high compared to CA 153 and CEA in breast cancer. ROC curve analyses of a combination of miR-21, miR-155, and miR-365 yielded much higher area under curve and enhanced sensitivity and specificity in comparison to each miRNA alone. Conclusion: The combination of serum miR-21/miR-155/miR-365 may potentially serve as a sensitive and specific biomarker that enables differentiation of breast cancer from healthy controls.

In Vivo Biocompatibility and Improved Compression Strength of Reinforced Keratin/Hydroxyapatite Scaffold

Jie Fan,Meng-Yan Yu,Tong-da Lei,Yong-Heng Wang,Fu-Yuan Cao,Xiao Qin,Yong Liu 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.2

A rapid freezing/lyophilizing/reinforcing process is suggested to fabricate reinforced keratin/hydroxyapatite (HA) scaffold with improved mechanical property and biocompatibility for tissue engineering. The keratin, extracted from human hair, and HA mixture were rapidly frozen with liquid nitrogen and then lyophilized to prepare keratin/HA laminar scaffold. The scaffold was then immersed in PBS for reinforcement treatment, and followed by a second lyophilization to prepare the reinforced keratin/HA scaffold. The morphology, mechanical, chemical, crystal and thermal property of the keratin/HA scaffold were investigated by SEM, FTIR, XRD, DSC, respectively. The results showed that the keratin/HA scaffold had a high porosity of 76.17 ± 3%. The maximum compressive strength and compressive modulus of the reinforced scaffold is 0.778 and 3.3 MPa respectively. Subcutaneous implantation studies in mice showed that in vivo the scaffold was biocompatible since the foreign body reaction seen around the implanted scaffold samples was moderate and became minimal upon increasing implantation time. These results demonstrate that the keratin/HA reinforced scaffold prepared here is promising for biomedical utilization.

Ameliorative effects of atractylodin on intestinal inflammation and co-occurring dysmotility in both constipation and diarrhea prominent rats

Changchun Yu,Yuan Lin,Yong-jian Xiong,Da-peng Chen,Yanli Li,Bin Xu,Zeyao Tang,Chunling Jiang,Li Wang 대한약리학회 2017 The Korean Journal of Physiology & Pharmacology Vol.21 No.1

Intestinal disorders often co-occur with inflammation and dysmotility. However, drugs which simultaneously improve intestinal inflammation and cooccurring dysmotility are rarely reported. Atractylodin, a widely used herbal medicine, is used to treat digestive disorders. The present study was designed to characterize the effects of atractylodin on amelioration of both jejunal inflammation and the co-occurring dysmotility in both constipation-prominent (CP) and diarrheaprominent (DP) rats. The results indicated that atractylodin reduced proinflammatory cytokines TNF-α, IL-1β, and IL-6 in the plasma and inhibited the expression of inflammatory mediators iNOS and NF-kappa B in jejunal segments in both CP and DP rats. The results indicated that atractylodin exerted stimulatory effects and inhibitory effects on the contractility of jejunal segments isolated from CP and DP rats respectively, showing a contractile-state-dependent regulation. Atractylodininduced contractile-state-dependent regulation was also observed by using rat jejunal segments in low and high contractile states respectively (5 pairs of low/ high contractile states). Atractylodin up-regulated the decreased phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK), and MLCK mRNA expression in jejunal segments of CP rats and down-regulated those increased parameters in DP rats. Taken together, atractylodin alleviated rat jejunal inflammation and exerted contractile-state-dependent regulation on the contractility of jejunal segments isolated from CP and DP rats respectively, suggesting the potential clinical implication for ameliorating intestinal inflammation and co-occurring dysmotility.

Antisurvivin oligonucleotides inhibit growth and induce apoptosis in human medullary thyroid carcinoma cells

Zhen-Xian Du,Hai-Yan Zhang,Da-Xin Gao,Hua-Qin Wang,Yong-Jun Li,Guo-Liang Liu 생화학분자생물학회 2006 Experimental and molecular medicine Vol.38 No.3

apoptosis protein (IAP) family, which is known to be over-expressed in various carcinomas and associated with their biologically aggressive characteristics. The aim of this study was to investigate survivin expression in human medullary thyroid carcinoma (MTC) and a MTC cell line TT, correlate suvivin expression with clinicopathologic features of MTC, and test effects of antisurvivin oligonucleotides (ASODNs) on growth and apoptosis of TT cells. Survivin expression was immunohistochemically determined in formalin-fixed and paraffinembedded specimens obtained from 10 cases of normal thyroid (NT) and 10 cases of MTC, and in TT cells. In TT cells, we confirmed survivin expression and its down-regulation by ASODNs using RT-PCR and Western blot analyses, and investigated effects of ASODNs on viability and growth by MTT assay and apoptosis by apoptotic analyses including DNA laddering assay, acridine orange/ethidium bromide staining and flow cytometric cell cycle analysis. Immunohistochemical analysis showed high survivin expression in MTC and TT cells, whereas no immunoreactivity was detectable in NT. Statistical analyses revealed no significant correlation of survivin expression with the clinicopathologic features of MTC. In TT cells, survivin expression at both mRNA and protein levels was confirmed and could be down-regulated by ASODNs concomitant with decrease in viability and growth, and increase in apoptosis. Our results suggest that survivin plays an important role in MTC independent of the conventional clinicopathologic factors, and ASODNs is a promising survivin- targeted gene therapy for MTC.

Genetic diversity and population structure of the amylolytic yeast Saccharomycopsis fibuligera associated with Baijiu fermentation in China

Wang Ju-Wei,Han Pei-Jie,Han Da-Yong,Zhou Sen,Li Kuan,He Peng-Yu,Zhen Pan,Yu Hui-Xin,Liang Zhen-Rong,Wang Xue-Wei,Bai Feng-Yan 한국미생물학회 2021 The journal of microbiology Vol.59 No.8

The amylolytic yeast Saccharomycopsis fibuligera is a predominant species in starters and the early fermentation stage of Chinese liquor (Baijiu). However, the genetic diversity of the species remains largely unknown. Here we sequenced the genomes of 97 S. fibuligera strains from different Chinese Baijiu companies. The genetic diversity and population structure of the strains were analyzed based on 1,133 orthologous genes and the whole genome single nucleotide polymorphisms (SNPs). Four main lineages were recognized. One lineage contains 60 Chinese strains which are exclusively homozygous with relatively small genome sizes (18.55–18.72 Mb) and low sequence diversity. The strains clustered in the other three lineages are heterozygous with larger genomes (21.85–23.72 Mb) and higher sequence diversity. The genomes of the homozygous strains showed nearly 100% coverage with the genome of the reference strain KPH12 and the sub-genome A of the hybrid strain KJJ81 at the above 98% sequence identity level. The genomes of the heterozygous strains showed nearly 80% coverage with both the sub-genome A and the whole genome of KJJ81, suggesting that the Chinese heterozygous strains are also hybrids with nearly 20% genomes from an unidentified source. Eighty-three genes were found to show significant copy number variation between different lineages. However, remarkable lineage specific variations in glucoamylase and α-amylase activities and growth profiles in different carbon sources and under different environmental conditions were not observed, though strains exhibiting relatively high glucoamylase activity were mainly found from the homozygous lineage.