Effect of Tissue Engineering Small Vessel Scaffolds in Experimental Animals

( Hua Yong Chen ),( Shu Ling Bai ),( Ying Qing Chen ) 한국조직공학·재생의학회 2012 조직공학과 재생의학 Vol.9 No.3

Acellular xenogeneic small vessel scaffolds preliminarily eliminate the xenogeneic antigen that could induce an immune rejection. We transplanted the Wistar rat caudal artery scaffolds into Japanese white rabbit ear central arteries, and observed the changes of blood flow and vessel wall. We acquired 30 caudal arteries from 15 Wistar rats, some were directly assigned as caudal artery group, the others were disposed by 1% p-octyl polyethelene glycol phenyl ether, and were assigned as the group of tissue engineered small vessel scaffold. We collected 15 Japanese white rabbits, and utilized a pair of ear central arteries per rabbit as hosts. Through microscopic surgery, the proximal broken end of central artery was overlapped into the donor`s proximal vessel lumen by sleeve anastomosis, while the distal broken end was sutured by classical end-to-end anastomosis. The maximum patency time of small vessel scaffold was 46 hours and 47 minutes, and which of caudal vessel was 14 hours. The poor blood flow primarily was occurred in distal broken end, while proximal end was connected in pedicle graft structure. On the 10th day, tunica intima fibers in vessel scaffold were still arranged in cylindrical conformation regularly without cell adherence. On the 100th day, tunica intima fibers were still preserved completely in proximal end. The results showed that xenogeneic acellular small vessel scaffold can be transplanted into the host, and the sleeve anastomosis was significantly superior to the classical end-to-end anastomosis.

Reduction of Brain Infarct Size and Extracellular Glutamate Accumulation by Dihydrokinate in Spontaneously Hypertensive Rat after Transient Forebrain Ischemia

Yong Hua Zhang,Yong Cai Li,Zheng Hua Cai,Yang Chen 대한신경외과학회 2004 Journal of Korean neurosurgical society Vol.36 No.4

Objective : Using bilateral carotid artery occlusion, controlled hypotension and in vivo microdialysis, we evaluate the changes in extracellular concentrations of the excitatory amino acids(EAA) glutamate and aspartate in the striatum of ischemic Wistar-Kyoto rats(WKY) and spontaneously hypertensive rats (SHR), as well as the resulting changes of infarct volume and neurological deficit scores. Methods : During 30 minutes of ischemia, microdialysate concentrations of glutamate and aspartate were measured in the presence of infusion of artificial cerebrospinal fluid(aCSF) or the dihydrokinate (DHK, the GLT-1 selective nontransportable inhibitor)-containing aCSF respectively. And infarct volume of neurological deficit were measured for each groups using triphenyltetrazolium chloride(TTC) staining and neurological deficit function tests. Results : In control aCSF infusing WKY group, glutamate and aspartate concentrations increased 36-fold and 14- fold increase to baseline, respectively, and returned to baseline values on reperfusion; while in control aCSF infusing SHR group, glutamate and aspartate increased 51-fold and 25-fold increase respectively. DHK (10nM) significantly attenuated EAA increases in both experimental WKY group and SHR group compared with control (glutamate peak for WKY, 7.09±1.04 versus control, 18.48±1.87 pmol/ul; for SHR, 18.90±1.54 versus control, 40.64±2.38 pmol/ul). There is a significant improving with neurological deficit score in DHK application groups both in WKY and SHR, which was also convinced by comparison of infarct volume between experimental DHK infusing group and control. Conclusion : Our results suggest that the astrocytic glutamate transporter contributes significantly to EAA release in the early phase of ischemia and inhibition of excessive glutamate release by DHK may contribute to effective treatment in ischemia-induced brain damage.

Effect of the Oxygen Flux Ratio on the Structural and the Optical Properties of Silver-oxide Films Deposited by Using the Direct-current Reactive Magnetron Sputtering Method

Xiao-Yong Gao,Hong-Liang Feng,Zeng-Yuan Zhang,Jiao-Min Ma,Meng-Ke Zhao,Chao Chen,Jin-Hua Gu,Shi-E Yang,Yong-Sheng Chen,Jing-Xiao Lu 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.2

Using values of the oxygen flux ratio (OFR = [O2]/[Ar]) ranging from 0 to 0.5, authors deposited a series of silver-oxide (Ag_xO) films on glass substrates by direct-current reactive magnetron sputtering (DC sputtering) at a substrate temperature of 150 ℃. The effect of the OFR on the film’s structural and optical properties was systematically investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The Ag_xO films deposited clearly show an evolution of the film’s phase structure from the biphased (Ag + Ag_2O) structure to the biphased (AgO + Ag_2O) structure and then to the single-phased (Ag_2O) structure as value of the OFR increases. Accordingly, the film’s surface morphology, related to the film’s crystalline structure, clearly changes from a loose and porous surface structure to a compact surface structure and then to a pyramid-like surface structure with increasing value of the OFR. The novel porous structure may be attributed to the interruption of the silver’s growth course by the AgO on the film’s surface. Notably, a single-phased Ag_2O film is deposited by DC-sputtering at OFR = 0.5 due to the dual effects of thermal decomposition of the AgO phase and a combination reaction of AgO and Ag to Ag_2O. The oscillations both in the film’s reflectivity and transmissivity spectra are strengthened with increasing OFR, indicating an evolution from the metallic behavior of the biphased (Ag + Ag_2O) film to the dielectric behavior of the biphased (Ag_2O + AgO) film and the single-phased Ag2O film. The fitted optical absorption edges of the Ag_2O and the Ag_xO films deposited at values of the OFR of 0.5 and 0.33 are approximately 2.43 eV and 2.34 eV, respectively. The absorption edges are closely related to the direct interband transitions.

Unilateral ureteral obstruction causes gut microbial dysbiosis and metabolome disorders contributing to tubulointerstitial fibrosis

Lin Chen,Dan-Qian Chen,Jing-Ru Liu,Jun Zhang,Nosratola D. Vaziri,Shougang Zhuang,Hua Chen,Ya-Long Feng,Yan Guo,Ying-Yong Zhao 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Chronic kidney disease (CKD) increases the risk and prevalence of cardiovascular disease (CVD) morbidity and mortality. Recent studies have revealed marked changes in the composition of the microbiome and the metabolome and their potential influence in renal disease and CVD via the accumulation of microbial-derived uremic toxins. However, the effect of unilateral ureteral obstruction (UUO) on the gut microbiome and circulating metabolites is unknown. Male Sprague-Dawley rats were randomized to UUO and sham-operated control groups. Renal histology, colonic microbiota, and plasma metabolites were examined two weeks later. We employed 16S rRNA sequence and untargeted metabolomic analyses to explore the changes in colonic microbiota and plasma metabolites and their relationship with tubulointerstitial fibrosis (TIF). The UUO rats exhibited tubular atrophy and dilatation, interstitial fibrosis and inflammatory cell infiltration in the obstructed kidney. UUO rats showed significant colonic enrichment and depletion of genera. Significant differences were identified in 219 plasma metabolites involved in lipid, amino acid, and bile acid metabolism, which were consistent with gut microbiota-related metabolism. Interestingly, tryptophan and its metabolites kynurenine, 5-hydroxytryptophan and 5-hydroxytryptamine levels, which were linked with TIF, correlated with nine specific genera. Plasma tryptophan level was positively correlated with Clostridium IV, Turicibacter, Pseudomonas and Lactobacillales, and negatively correlated with Oscillibacter, Blautia, and Intestinimonas, which possess the genes encoding tryptophan synthase (K16187), indoleamine 2,3-dioxygenase (K00463) and tryptophan 2,3-dioxygenase (K00453) and their corresponding enzymes (EC:1.13.11.52 and EC:1.13.11.11) that exacerbate TIF. In conclusion, UUO results in profound changes in the gut microbiome and circulating metabolites, events that contribute to the pathogenesis of inflammation and TIF.

Synthesis and DNA-binding Properties of Trehalose-tethered Monomeric and Dimeric Berberines

Yong-Min Wang,Chun-Qiong Zhou,Jin-Xiang Chen,Wen-Hua Chen 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

Trehalose-tethered monomeric and dimeric berberines were synthesized in 50% and 30% from the reaction of berberrubine with 6-tosyl-α,α'-trehalose and 6,6'-ditosyl-α,α'-trehalose, respectively, and fully characterized by MS (HR and ESI) and NMR (1H, 13C, COSY and HSQC). Spectrophotometric and spectrofluorimetric titrations indicated that compared with berberine, trehalose-tethered monomeric berberine had comparable DNA-binding affinity toward calf-thymus DNA, whereas trehalose-spaced dimeric berberine exhibited higher DNA-binding affinity. The potential application of these conjugates is also briefly discussed.

Effects of contraction-type impeller on non-overloaded performance for low-specific-speed sewage pump

Hua Zhang,Bin Chen,Wei-dong Shi,Zhong-yong Pan,Wei-dong Cao 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

With the expansion of the engineering application of solid-liquid two-phase flow, the overload characteristics of low-specific-speedsewage pumps become an important obstacle to the development of the products. In this paper, the traditional diffusion-type impeller isutilized to carry out hydraulic design of a low-specific-speed sewage pump. And on this basis, the thickness of the blades is increased forgetting an impeller with contractive-type flow channel. It was found out that through external characteristics, the efficiency of contraction-type impeller is slightly lower than that of diffusion-type impeller, but it shows obvious non-overload performance. PIV experimentis arranged to find the inherent. The results show that although internal flow field distribution of contraction-type impeller is better thanthat of diffusion-type impeller, the severe uneven distribution of absolute velocity of the impeller outlet along the circumference is one ofmain reasons of inefficiency. In addition, another five impellers with different contraction ratio are designed to research relationship betweencontraction ratio and character of non-overload. The characteristics are predicted by CFD, and after comparing the results, it isfound out that, the smaller the contraction ratio is, the closer the condition of power extreme is to the design condition, which has importantimplications for the engineer.

Thermodynamics and Kinetics of Lysozyme Adsorption onto Two Kinds of Weak Cation Exchangers

Yong-Mei Cheng,Xiong-Hua Jin,Dong Gao,Hai-Feng Xia,Jing-Hua Chen 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5

The present work investigated the adsorption behaviors of lysozyme onto weak cation exchangers at different temperatures. The adsorption isotherm, adsorption thermodynamics and adsorption kinetics were studied. The results indicate that the adsorption of lysozyme onto acrylic acid copolymer based beads (Hydrolite D115) is spontaneous and exothermic, while that onto agarose based beads (CM Sepharose 6 Fast Flow) is also spontaneous, but endothermic. The pseudo second-order kinetic model fits well to the dynamic adsorption experimental data, and the kinetic results are also in concert with the adsorption thermodynamics.

Transverse impact characteristics of a rubber pipe expansion joint

Yong Chen,Wang Yu,ZhiYi Zhang,Hongxing Hua 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.6

The transverse impact characteristics of a rubber pipe expansion joint are studied. A pair of joints assembled end to end with an inserted middle mass is tested on a drop shock testing machine. Based on the test results, an equivalent fixed-fixed beam model with polynomial stiffness and damping is applied to predict the transverse impact response and identify the nonlinear impact parameters. The least square residual between the computed and test results is defined to drive the identification optimization. The response surface methodology in combination with the generalized reduced gradient method is used to search the best matching coefficients. Final results show that the equivalent bending stiffness of the tested rubber expansion joint gradually decreases with the transverse deformation and is greatly influenced by its internal working pressure.

Air Injection System Design Based On Critical Pore-Gas Velocity for Landfill Aeration

( Hua-yong Wu ),( Hong-tao Wang ),( Wen-jing Lu ),( Tan Chen ) 한국폐기물자원순환학회 2011 ISWA Vol.2011 No.0

A Retrospective Study of the Effect of Spinopelvic Parameters on Fatty Infiltration in Paraspinal Muscles in Patients With Lumbar Spondylolisthesis

Jia-Chen Yang,Jia-Yu Chen,Yin Ding,Yong-Jie Yin,Zhi-Ping Huang,Xiu-Hua Wu,Zu-Cheng Huang,Yi-Kai Li,Qing-An Zhu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion: FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.