Advanced Materials Research Vol. 773

Abstract: In this paper, the batch rectification operation is adopted to keep distillate constituting constant high vacuum, in the operation process, the operation of variable reflux ratio is carries out. Through studying the relational system of reflux ratio, column top product composition, rectification time and theoretical plate number, when the concentration of citronellal extract column product is 99%, the appropriate reflux ratio is 0.8-15, and the graphic method is used to design13 pieces of theoretical plate number of citronellal extract column, providing powerful data support for the process design of citronellal extract column.

Abstract: In this paper, the superoxide dismutase from Martianus dermestoides is purified by the following methods: heat treatment, polyethylene concentration, Sephadex G-75 gel filtration, and DEAE-Sepharose FF ion exchange chromatography. The result shows that the purification multiple is 3.86, the activation yield is 21.89% and the specific activation of the enzyme is 447.6 U/mg. The purified SOD appears to be a sole protein on SDS-PAGE and the molecular weight is estimated to be 40.58 kDa. H₂O₂ can obviously inhibit the enzyme activation and CHCl₃-CH₃CH₂OH only demonstrates basically no inhibitory effect. The type of the dermestoides SOD might be Cu/Zn-SOD. After purification, some enzymatic characterizations of the SOD are studied. The optimum reaction temperature of purified SOD is 50°C. The optimum reaction pH value of purification is 6. The dermestoide SOD has a preferable stability below 50°C and at pH values between 5-8.

Abstract: Objective To investigate the expression of HIF-la in entochondrostosis,and to study its role in the process of vascular intrusion.Methods The morphology change in rats femoral bone development were observed using HE staining method.The protein expression Of HIF-Ia and VEGF in femoral bone was detected by immunohistochemistry,and the mRNA expression of HIF-Ia and VEGF was detected by reverse transcription-polymerase chain reaction (RT-PCR) method.Results: Many cartilage cells were seen in femoral bone at the 1st day after the birth;many vessels began to invade at the 7th dayfat the 13th day,the cartilage matrix began to calcification,vessels and cartilage cells were reduced.The protein expression of HIF-la and VEGF was increased at the 7th daywhile decreased at the 13th day.The mRNA expression of HIF-la and VEGF went up to the maximum at 7th day the time,and then decreased.Conclusion During femoral bone development,hypoxia may induce HIF-I expression,then activates its downstream gene VEGF expression,which would induce the intrusion of exogenous vascular.Promote endochondral osteogenesis.

Abstract: The membrane-aerated bioreactor (MABR) was specially designed to evaluate its suitability for the treatment of an artificial sewage in laboratory. The paper presented the configuration of the MABR, the effect of variation of partial oxygen pressures on treatment efficiency (COD, NH₄⁺-N, NO₃^--N), and the theoretical analysis on COD efficiency. The partial oxygen pressures were changed to investigate experimentally its influence on the removal of COD, NH₄⁺-N and NO₃^--N. Results showed that when partial oxygen pressures was below 40KPa, COD and NH₄⁺-N removal efficiency increased with its increasing, meanwhile, nitrification was the main control process in simultaneous nitrification and denitrification (SND); with partial oxygen pressures above 40KPa, the COD and NH₄⁺-N removal efficiency wasnt affected by it, and denitrification became the main control process in SND. However, denitrification would be restrained if the partial oxygen pressure overtops a certain value. The partial oxygen pressure had more significant influence on COD than NH₄⁺-N removal efficiencies. The reaction rate of COD remove in the MABR had zero-order reaction characteristics.

Abstract: Activated sludge process has been applied worldwide in municipal and industrial wastewater treatment practices. Excess sewage sludge, produced in sedimentation after wastewater bio-treatment, is an inevitable by-product of wastewater treatment processes. In any case sludge treatment and disposal should always be considered as an integral part of treatment of wastewater. Currently, the most widely available options in the world are the agriculture utilization, the waste disposal sites, the land reclamation and restoration, the incineration and other novel uses. Extracellular polymeric substances (EPS), as high-molecular weight compounds are secreted by activated sludge microorganisms, which can significantly influence the physicochemical properties and function of activated sludge flocs. Because of the crucial roles of EPS, many researchers have been made to explore their chemical compositions and physicochemical properties. Polysaccharides, humic substances and proteins are usually found to be the major components of EPS. The present paper sought to review past and future trends in sludge handling, focusing mainly at the organic matters.

Abstract: Panax ginseng (C.A.Meyer), belonging to Araliaceae family Panax category, has important commercial value and are used in worldwide. Ginsenosides, the major bioactive ingredients of P. ginseng, are classified into two groups by the skeleton of aglycones, namely dammarane-type and oleanane-type. Dammarane-type ginsenosides dominate over oleanane-type not only in amount but also in structural varieties. Here, we cloned and identified the Dammarenediol-II synthase gene named PNA encoding encoding enzymes catalyzed 2,3-oxidosqualene to dammarendediol-II by RT-PCT.we established PNA RNAi transgenic. The RT-PCT and HPLC analysis of the final products of protopanaxadiol-type and protopanaxatrio-type ginsenosides showed a result that declined level of protopanaxadiol-type and protoanaxatriol-type ginsenosides, and increased phytosterol content.

Abstract: Ginsenosides, the major bioactive ingredients of P. ginseng can improve the anti-disease abilities of human being, and generate significant social and economic benefits. However, along with gradually or rapidly or dramatically increasing demand of the ginsenosides, extensive studies have focused on regulating the ginsenoside biosynthetic pathway on a genetic level. This review provides the latest research progress on biosynthetic pathway of ginsenosides, including the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathway, which is newly discovered and located in P. ginseng. Moreover, it also indicated lanosterol synthase metabolic flux present in P. ginseng.

Abstract: Ginsenosides, the major bioactive ingredients of P. ginseng can improve the anti-disease abilities of human being, and generate significant social and economic benefits. However, along with gradually or rapidly or dramatically increasing demand of the ginsenosides, extensive studies have focused on regulating the ginsenoside biosynthetic pathway on a genetic level. In this article, ginsenoside biosynthesis of key enzyme genes are described, including squalene synthase (SS), squalene epoxidase (SE), oxidosqualene cyclase (OSC), dammarenediol synthase (DS), β-amyrin synthase (β-AS), lanosterol synthase (LAS), cycloartenol synthase (CAS) and P450. Additionally, this review critically analyzes and evaluates the background and theoretical basis of the previous researches, as well as the deficiencies of these researches.

Abstract: The microscopic structure Cu₄₆Zr₄₆Al₈ alloys were investigated by means of molecular dynamics simulations. This work gives the structure properties including partial pair-correlation function, pair analysis technique and Voronoi indices, and the temperature dependence. The simulated pair-correlation function is consistent well with the experimental one. We found that the the fractions of icosahedra and the distorted icosahedra increase with the decreasing temperature and become into the dominant clusters in the bulk metallic glass. At the meanwhile, we found that the icosahedra and the distorted icosahedra around Cu, Zr and Al are different. The Cu-center and Al-center icosahedra and the distorted icosahedra increase with the decreasing temperature, but The Zr-center icosahedra and the distorted icosahedra decrease with the decreasing temperature.

Abstract: The formability performance of automobile steel is one of the most important factors of product. This work presents the formability behavior of high strength automobile sheet metal by hole-expanding test. The test principle and experiment procedural are introduced. The average expansion ratio of 30 selected samples was 109%. The fracture appearance of two deviant samples and a normal one are compared and analyzed. The initial manufacturing flaw and low dimple concentration level are the possible reasons for the remote date.