Screening, Characterization, and Cloning of a Solvent-Tolerant Protease from Serratia marcescens MH6

( Mao Hua Wan ),( Wu Bin ),( Wei Ren ),( Bing Fang He ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.5

Genetic Diversity and Geographical Differentiation of Desmodium triflorum (L.) DC. in South China Revealed by AFLP Markers

Mao-feng Yue,Ren-chao Zhou,Ye-lin Huang,Guo-rong Xin,Su-hua Shi,Li Feng 한국식물학회 2010 Journal of Plant Biology Vol.53 No.2

High levels of genetic variation enable species to adapt to changing environments and provide plant breeders with the raw materials necessary for artificial selection. In the present study, six AFLP primer pairs were used to assess the genetic diversity of Desmodium triflorum (L.)DC. from 12 populations in South China. A high percentage of polymorphic loci (P=76.16%) and high total gene diversity (HT=0.310) were found, indicating that the genetic diversity of D. triflorum is high at the species level. Genetic diversity was also relatively high at the population level (P=55.85%, He=0.230). The coefficient of gene differentiation among populations (GST) was 0.255, indicating that while most genetic diversity resided within populations, there was also considerable differentiation among populations. AMOVA also indicated 24.29% of the total variation to be partitioned among populations (ΦST=0.243). UPGMA clustering analysis based on genetic distances showed that the 12 populations could be separated into three subgroups: an eastern, a western, and a central-southern subgroup. However, a Mantel test revealed no significant correlation (r=0.286, p=0.983)between the geographical distances and genetic distances separating these populations; mountain barriers to gene flow and human disturbance may have confounded these correlations. The present study has provided some fundamental genetic data that will be of use in the exploitation of D. triflorum.

Experimental and analytical investigation on RC columns with distributed-steel bar

Mao Ye,Yinpei Pi,Min Ren 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

Distributed-Steel Bar Reinforced Concrete (DSBRC) columns, a new and innovative construction technique for composite steel and concrete material which can alleviate the difficulty in the arrangement of the stirrup in the column, were studied experimentally and analytically in this paper. In addition, an ordinary steel Reinforced Concrete (SRC) column was also tested for comparison purpose. The specimens were subjected to quasi-static load reversals to model the earthquake effect. The experimental results including the hysteresis curve, resistance recession, skeleton curves and ductility ratio of columns were obtained, which showed well resistant-seismic behavior for DSBRC column. Meanwhile a numerical three-dimensional nonlinear finite-element (FE) analysis on its mechanical behavior was also carried out. The numerically analyzed results were then compared to the experimental results for validation. The parametric studies and investigation about the effects of several critical factors on the seismic behavior of the DSBRC column were also conducted, which include axial compression ratios, steel ratio, concrete strength and yield strength of steel bar.

A κ-Carrageenase from a Newly Isolated Pseudoalteromonas-like Bacterium, WZUC10

Mao-hong Zhou,Jian-she Ma,Jun Li,Hai-ren Ye,Ke-xin Huang,Xiao-wei Zhao 한국생물공학회 2008 Biotechnology and Bioprocess Engineering Vol.13 No.5

A bacterial strain able to produce k-carrageenase, designated WZUC10, was isolated from a live specimen of the red alga Plocamium telfairiae collected in the East China Sea. The phylogenetic evidence and phenotypic features indicate that this strain belongs to the genus Pseudoalteromonas. WZUC10 requires NaCl for growth and k-carrageenan to induce k-carrageenase synthesis; galactose and lactose do not induce it. The optimal growth temperature is 23~27°C. The secreted enzyme, which has a molecular mass of 45 kDa, breaks down k-carrageenan into k-neocarratetraose sulfate and larger oli-gosaccharides with a repeating β-D-Galp4S-(1→4)-α-D-AnGalp structure, but cannot degrade k-neocarratetraose sulfate or k-neocarrahexaose sulfate into k-neocarrabiose sulfate. The enzyme retains 90% of its activity after 2 h at 40°C and is com-pletely inactivated after 7.5 min at 70°C. The enzyme’s optimal temperature is 30°C and its optimal pH is 7.5. The enzyme-catalyzed reaction follows Michaelis-Menten kinetics, with the Michaelis constant (Km) and the turnover number (k) being 0.015 mM and 125 s-¹, respectively. WZUC10 produces 50 U/mL k-carrageenase after cultivation at 25°C for 35 h on a me-dium containing 80 g/L glucose, 5 g/L corn steep liquor, 3 g/L k-carrageenan, and 15 g/L NaCl. k-Neocarratetraose sulfate was prepared simply with precipitation by ethanol:water (5:1, v/v).

Effect of Rapid Chilling on Beef Quality and Cytoskeletal Protein Degradation in M. longissimus of Chinese Yellow Crossbred Bulls

Mao, Yanwei,Zhang, Yimin,Liang, Rongrong,Ren, Lulu,Zhu, He,Li, Ke,Zhu, Lixian,Luo, Xin Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.8

The objective of this study was to investigate the effect of rapid chilling (RC) on beef quality and the degradation of cytoskeletal proteins. Twenty Chinese Yellow crossbred bulls were selected and randomly divided into two groups. RC and conventional chilling (CC) were applied to left and right sides of the carcasses respectively after slaughtering. To determine whether electrical stimulation (ES) treatment can alleviate the potential hazard of RC on meat quality, ES was applied to one group. The effects of RC and ES were determined by meat color, shear force and cytoskeletal protein degradation postmortem (PM). The results showed that RC decreased beef tenderness at 1 d and 3 d postmortem, but had no detrimental effect on meat color. Western blotting showed that RC decreased the degradation rate of desmin and troponin-T, but the effects weakened gradually as postmortem aging extended. Degradation rates of both desmin and troponin-T were accelerated by ES. The combination of RC and ES could improve beef color, accelerate degradation rate of cytoskeletal protein and improve beef tenderness.

Isolation and Characterization of a Novel Heterotrophic Nitrifying and Aerobic Denitrifying Bacterium Pseudomonas stutzeri KTB for Bioremediation of Wastewater

Mao-hong Zhou,Hai-ren Ye,Xiao-wei Zhao 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.2

A novel heterotrophic nitrifying and aerobicdenitrifying bacterium, KTB, was isolated from activatedsludge flocci collected from a biological aerated filteraccording to the modified Takaya method and identified asPseudomonas stutzeri by 16S rDNA gene sequence analysis. When shaking-cultured in the presence of 4.331 mmol/L ofnitrate, 4.511 mmol/L of nitrite and 4.438 mmol/L ofammonium, the strain grew fast, with μmax being 0.42, 0.45,and 0.56/h, and displayed high nitrogen removal efficiency,with nitrogen removal rate being 0.239, 0.362, and 0.361mmol/L/h and nitrogen removal ratio being 99.1, 100.0,and 100.0% in 18 h, respectively. The removal mainlyoccurred in the logarithmic phase. Nitrite accumulation didnot affect denitrification performance. Nitrate concentrationwas below the detectable limit during the whole growthcycle when ammonium was used as sole nitrogen source. It tolerated high DO level and exhibited excellent aggregationability. A possible pathway involved in the nitrogenremoval process, which demonstrated a full nitrificationand denitrification route, was speculated. The strain mightbe a great candidate for biological removal of nitrogencompounds from wastewater.

Experimental and analytical investigation on RC columns with distributed-steel bar

Ye, Mao,Pi, Yinpei,Ren, Min Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

Distributed-Steel Bar Reinforced Concrete (DSBRC) columns, a new and innovative construction technique for composite steel and concrete material which can alleviate the difficulty in the arrangement of the stirrup in the column, were studied experimentally and analytically in this paper. In addition, an ordinary steel Reinforced Concrete (SRC) column was also tested for comparison purpose. The specimens were subjected to quasi-static load reversals to model the earthquake effect. The experimental results including the hysteresis curve, resistance recession, skeleton curves and ductility ratio of columns were obtained, which showed well resistant-seismic behavior for DSBRC column. Meanwhile a numerical three-dimensional nonlinear finite-element (FE) analysis on its mechanical behavior was also carried out. The numerically analyzed results were then compared to the experimental results for validation. The parametric studies and investigation about the effects of several critical factors on the seismic behavior of the DSBRC column were also conducted, which include axial compression ratios, steel ratio, concrete strength and yield strength of steel bar.

Surgical management of inflammatory bowel disease in China: a systematic review of two decades

( Qiao Yu ),( Ren Mao ),( Lei Lian ),( Siew Chien Ng ),( Shenghong Zhang ),( Zhihui Chen ),( Yanyan Zhang ),( Yun Qiu ),( Baili Chen ),( Yao He ),( Zhirong Zeng ),( Shomron Ben-horin ),( Xinming Song 대한장연구학회 2016 Intestinal Research Vol.14 No.4

Background/Aims: The past decades have seen increasing incidence and prevalence of inflammatory bowel disease (IBD) in China. This article aimed to summarize the current status and characteristics of surgical management for IBD in China. Methods: We searched PubMed, Embase, and Chinese databases from January 1, 1990 to July 1, 2014 for all relevant studies on the surgical treatment IBD in China. Eligible studies with sufficient defined variables were further reviewed for primary and secondary outcome measures. Results: A total of 74 studies comprising 2,007 subjects with Crohn`s disease (CD) and 1,085 subjects with ulcerative colitis (UC) were included. The percentage of CD patients misdiagnosed before surgery, including misdiagnosis as appendicitis or UC, was 50.8%±30.9% (578/1,268). The overall postoperative complication rate was 22.3%±13.0% (267/1,501). For studies of UC, the overall postoperative complication rate was 22.2%±27.9% (176/725). In large research centers (n>50 surgical cases), the rates of emergency operations for CD (P =0.032) and in-hospital mortalities resulting from both CD and UC were much lower than those in smaller research centers (n≤50 surgical cases) (P =0.026 and P <0.001, respectively). Regarding the changes in CD and UC surgery over time, postoperative complications (P =0.045 for CD; P =0.020 for UC) and postoperative in-hospital mortality (P =0.0002 for CD; P =0.0160 for UC) both significantly improved after the year 2010. Conclusions: The surgical management of IBD in China has improved over time. However, the rates of misdiagnosis and postoperative complications over the past two decades have remained high. Large research centers were found to have relatively better capacity for surgical management than the smaller ones. Higher quality prospective studies are needed in China. (Intest Res 2016;14:322-332)

A study on the improvements of geotechnical properties of in-situ soils by grouting

Chang, Muhsiung,Mao, Tze-wen,Huang, Ren-chung Techno-Press 2016 Geomechanics & engineering Vol.10 No.4

This paper discusses improvements of compressibility, permeability, static and liquefaction strengths of in-situ soils by grouting. Both field testing and laboratory evaluation of the on-site samples were conducted. The improvement of soils was influenced by two main factors, i.e., the grout materials and the injection mechanisms introduced by the field grouting. On-site grout mapping revealed the major mechanism was fracturing accompanied with some permeation at deeper zones of sandy soils, where long-gel time suspension grout and solution grout were applied. The study found the compressibility and swelling potential of CL soils at a 0.5 m distance to grout hole could be reduced by 25% and 50%, respectively, due to the grouting. The effect on hydraulic conductivity of the CL soils appeared insignificant. The grouting slightly improved the cohesion of the CL soils by 10~15 kPa, and the friction angle appeared unaffected. The grouting had also improved the cohesion of the on-site SM soils by 10~90 kPa, while influences on the friction angle of soils were uncertain. Liquefaction resistances could be enhanced for the sandy soils within a 2~3 m extent to the grout hole. Average improvements of 40% and 20% on the liquefaction resistance were achievable for the sandy soils for earthquake magnitudes of 6 and ${\geq}7.5$, respectively, by the grouting.

폴리(스티렌-이소부틸렌-스티렌) 삼중블록 공중합체의 합성, 분석 및 혈액적합성

Wen Li Guo,Ping Ren,Yi Bo Wu,Shu Xin Li,Jing Mao,Fei Xiao,Kang Li 한국고분자학회 2011 폴리머 Vol.35 No.1

The synthesis of well-defined poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock copolymers was accomplished by cationic sequential block copolymerization of isobutylene (IB) with styrene (St) using 1,4-di(2-chloro-2-propyl)benzene (DCC)/TiCl4 /2,6-di-tert-butylpyridine(DtBP) as an initiating system in methyl chloride (CH3Cl)/methylcyclohexane(MeChx) (50/50 v/v) solvent mixture at -80 ℃. The triblock copolymers exhibited excellent thermoplastic and elastomeric characteristics. Tensile strengths and Shore hardness increased with increasing polystyrene (PS) content, while elongation at break decreased. The blood-compatibility of SIBS was assessed by SEM observation of the platelet adhesion, blood clotting time and haemolysis ratio. The haemolysis ratios were below 5% which met the medical materials standard. The platelet adhesion test further indicated that SIBS block copolymers had a good blood compatibility.