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Table of Content

    25 May 2006, Volume 34 Issue 5
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    Safety Management Engineering
    Quantitative Risk Assessment of Liquefied Chlorine Leakage Accident via SAFETI
    Chen Guo-hua Liang Tao Zhang Hui Yah Wei-wen Chen Qing-guang
    2006, 34(5):  103-108. 
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    Based on the analysis of safety status and the statistic of accidents in the storage and transportation of lique-fled chlorine,the hazard characteristics of chlorine and the poison fatalness caused by the leakage in the storage and transportation of liquefied chlorine are analyzed,with the quantitative risk-analyzing software SAFETI(Software for Assessment of Flammable,Explosive and Toxic Impacts)in the DNV being adopted.Then,the types of leakage accidents that may happen in the storage and transportation of liquefied chlorine are summed up,and a quantitative assessment for the toxic consequence and risk in a liquefied chlorine tanker leakage is carried out using SAFETI,with the relevant assessment models being established.By the proposed models,the consequences and risks of accidents are forecasted and simulated,and the hazard degree and rang,as well as the individual risk and societal risk caused by the accidents are simulated in the form of graphs and reports,which helps forecast and prevent leak-age accidents in practice and helps reduce personnel casualty and property loss.

    Engineering Applications of TNO Multi-Emnergy Method in VCE Simulation Assessment
    Zhang Rui-hua Chen Guo-hua Zhang Hui Chen Qing-guang Yah Wei-wen
    2006, 34(5):  109-114. 
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    This paper focuses on the engineering applications of TNO(The Netherlands Organization)Multi-Energy method,analyzes the existing problems and provides corresponding solutions to improve the applicability of the method,in addition to the rules to select the strength grade of explosion source.In order to avoid the error due to the manual reading from blast wave curves,the characteristic curves of TNO blast wave are replaced by their fitting expressions,and some of the expressions resulting in big eror are modified.Moreover,according to the overpres-sure causing injury to the lung and the eardrum,as well as the fitting expressions of the characteristic curves,the expressions describing diferent injury distances are deduced by ineans of the iteration method and the least square method and are further verified.It is shown that the proposed expressions are feasible in engineering because their formats are simple and few inputs are needed.

    Materials Science & Technology
    Synthesis and All-Optical Switching Efect of Polymer Containing Pseudo-Stilbene Chromophores
    Wu Shui-zhu Gong Shuai Zhu Hong-ping Yang Yang She Wei-long Luo Duan-bin
    2006, 34(5):  81-85. 
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    First,a new pseudo-stilbene chromophore was synthesized and the corresponding monomer was obtained by means of acylation reaction.Next,a kind of polymer with pseudo-stilbene chromophores as the side groups was prepared by the radical polymerization of the above-mentioned monomer and acrylate monomer.Then,the chromo-phore monomer and the coresponding polymer were structurally characterized using HNMR,FTIR and UV-Vis spectroscopy.Finally,the all-optical switching effect of the polymer was experimentally investigated.The results indicate that,with the iradiation of pump beam,the repetition of trans-cis-trans photoisomerization of pseudo-stil-bene groups leads to a photoinduced anisotropy in the polymer,and that the all-optical switching effect can be realized with a low optical driving power of 8 mW .

    Investigation into Surface Properties of Superfine M aterials via Photon-Detecting Analytics
    Bi Shu Zhou Xi-ya Guo Guo-zhang Xie Xian-de
    2006, 34(5):  86-89. 
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    The particle size distributions and morphologies of two self-prepared superfine materials,that is,the SH-perfine heavy calcium carbonate powder and the PVC plastic membrane modified with superfine heavy calcium car-bonate powder,were investigated by means of the photon-detecting analytics.The corresponding results are then compared with those obtained by the traditional micro.zone analytics.SEM.The results indicate that the photon detection with dynamic light scattering is suitable for the analysis of particle size distribution of sub-micro superfine materials,while the laser condensing and focusing scanner with plane digital image are more suitable for the investigation of the dispersion of superfine material in plastic,as compared with SEM.Thus,a new analytical method is proposed for the investigation of surface properties of superfine materials.

    Efect of Microwave Heating and Doped ZrO2 on Phase Transformation from γ-Al2 O3→α-Al2 O3
    Zhou Xi-ya Bi Shu Fan Bo
    2006, 34(5):  90-93. 
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    The processing conditions r the phase transformation from γ-Al2 O3to α-Al2 O3caused by the common heating and microwave heating methods were analyzed by means of X—ray diffraction,with an enhancement of phase transform ation caused by microwave heating being revealed.The efect of doped ZrO2 on the phase transform ation was also studied.It is found that,compared with the common heating,microwave heating makes the phase transtbr-marion from γ-Al2 O3to α-Al2 O3happen at a lower temperature with higher speed,and that ZrO2 hinders the phase transform ation caused by microwave heating.

    Properties of Natural Rubber/Black Carbon Composite Modified with M aleic Anhydride
    Dong Zhi-xian Jia De-min Zhou Yan-hao
    2006, 34(5):  94-98. 
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    Natural rubber(NR)was grafted with maliec anhydride(MAH)monomer on a tow-roll mill,respec-tively with benzyl peroxide(BPO)and dicumyl peroxide(DCP)as the initiator.Then,the modified NR was mixed with high-abrasion black carbon(HAF)to prepare NR/HAF composite with excellent properties.The pro.perties of the prepared composite were also tested and discussed.The results indicate that the prepared NR/HAF composite modified with MAH is of good thermal stability even at high temperature and excellent mechanical proper.ties,especially with a MAH/DCP mass ratio of 1.0:0.5.and that DCP is better than BPO in initiating ability.Also,SEM photographs show that the dispersion and combination of HAF to NR matrix are improved due to the modification.

    Fractal Dimension of Size Distribution of Particle Group in Porous M edium Clay
    Hu Xiao-fang Hu Da-wei Wu Cheng-bao
    2006, 34(5):  99-102. 
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    The fractal dimension of size distribution of particles in porous medium clay is a index preferably reflecting the size distribution and space-packing capability of clay particles,which has been used to denote the capabili-ties of water holding and packing for soil.In this paper,a model that is appropriates for the calculation of fractal di-mension with digital micro-analysis is established,and a new method to calculate the fractal dimension is proposed-with some types of clays in South China as the porous medium samples.The results show that the value of fractal di-mension obtained by the proposed method ranges from 2.270 8 to 2.948 3,which accord with that obtained by oth.ers methods.Thus,great correctness and practicability of the proposed model and method are reveled,and a new method and coresponding criterion are presented for the evaluation or soil texture and the investigation into the packing and rheological capabilities,etc.

    Environment Science & Technology
    Stoichiometric Analysis of Combined Reaction of Anaerobic Ammonia Oxidation with Denitrificati0n
    Zhou Shao-qi
    2006, 34(5):  1-4. 
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    The progress in the research on anaerobic ammonia oxidation(ANAMMOX)is briefly reviewed,and the combined reaction of ANAMMOX with denitrifieation in the condition of organic carbon source is discussed.The electronic stoichiometric equations of ANAMMOX and the denitrification with glucose as the organic carbon are then derived.The electronic stoichiometric analyses demonstrate that the ANAMMOX process benefits from the simuha.neous denitrification because CO2,produced from organic carbon in the denitrification process can be used by ANAM MOX bacteria in the same bioreactor.and that the nitrate produced in the ANAMMOX process can be used by deni.trification bacteria.However,H+ is produced in both ANAMMOX and denitrification processes.As a result.the pH value tends to increase with the development of bio-reaction,which accords well with the reported experimental results.

    Correlation Between Particles with Satellite Droplet Structure and Haze
    Qian Gong-wang Zhao Ling-xia
    2006, 34(5):  5-10. 
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    The single aerosol particle in the haze in Guangzhou,which was size-fractionated into the coarse part (radius R>1.0 μm)and the fine part(radius R≤1.0 μm),was collected on the electron microscope screen for morphological analysis using transmission electron microscope.By the comparison of the shape of single aerosol par-ticle before and after the haze,apparent difference is revealed,and good correlation between the particles with sa-tellite droplet structure and the haze is demonstrated.Moreover,an increase in the number of acidic particles dur-ing the formation of haze is observed.

    Distribution of Alkylphenols in Surface W ater and Sediments flro m LinRg dinRg 1B5ay
    Chen Bing Mai Bi-xian Yang Qing-shu Duan Jing-chun Sheng Guo-ying Fu Jia-no
    2006, 34(5):  11-14. 
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    The alkylphenol(AP)in the surface water and sediments from Lingding Bay is determined by means of GC-MS method.The results show that 11 water samples out of 12 are polluted by AP,with the highest content up to 46 ng/L,that all the sediment samples contain AP with the content of 61 to 1236 ng/g,and that Macao Harbor is most seriously polluted,the AP content in the surface water in Lingding Bay seaward decreasing while that in the sediments seaward increasing to a maximum near Hong Kong,which is similar to the variation of total organic car-bon(TOC)content in the sediments.Furthermore,a remarkable correlation between AP content and TOC content is revealed by means of linear regression analysis.

    Analysis of Interlamellar Structure of Xinjiang Vermiculite Modified by Pillared Quaternary Ammonium with Diferent Chain Length
    Wu PING-xiao Li Rong Dang Zhi
    2006, 34(5):  15-19,37. 
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    In order to investigate the reaction mechanism of organic pillared hydrobiotite,a hydrobiotite from Weili.Xinjiang,that is,a vermiculite-phlogopite interstratified mineral.was modified by cationic surfactants of quaternary ammonium with different alkyl chain length.The complexes were then tested by X-ray diffraction and infrared spec-trum.The effects of the crystallization degree,the uniformity of charge distribution.the surrounding hydration cat-ion and the pillaring mode of organic molecule on the interlamellar space of hydrobiotite were finallv discussed.The results show that the quaternary ammonium cations(C12TA+ ,C14TA+)with short alkyl chain only react with the hydration cation in the interlamerllar space of hydrobiotite,while those with long chain(C16TA+ ,C18 TA+ )first react with the hydration cation,then with the kalium cation in phlogopite interlayer.

    Characteristics and Afecting Factors of Phosphorus Removal in Sequencing-Batch Biofilm Reactor
    Fang Qian Wei Chao-hai Zhang Chao-sheng Zhang Ke-fang Rong Hong-wei
    2006, 34(5):  20-25. 
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    In the biofilm reactor with continuous flow,the removal eficiency of phosphorus is very low,while those of organics and nitrogen are very high.In order to solve these problems,an alternating anaerobic/aerobic sequen-cing-batch biofilm reactor(SBBR)was built up.By reasonably controlling the anaerobic and aerobic time,the municipal wastewater in Guangzhou with low carbon content was then treated,and the eficiency and characteristics of phosphorus removal were investigated.The results show that the mass concentration of total phosphorus(TP)in the effluent reaches 0.085~0.5 mg/L at a influent TP content of 1.65~7.10ms/L.and that the removal rate reaches more than 90% .Moreover.by the further analyses of the characteristics and controlling factors of anaerobic and aerobic phases in SBBR,it is concluded that the alternating anaerobic/aerobic process is the prerequisite of effective phosphorus removal,that the maximum valid amount of released anaerobic phosphorus is key to the efficiently removal of phosphorus in SBBR due to the good correlation among the valid phosphorus release,the organic removal and the phosphorous removal eficiency.

    Mechanical Engineering
    Numerical Simulation of One-Path Neck·Spinning of Oblique Tubes
    Xia Qin-xiang Liang Bai-xiang Cheng Xiu-quan Ruan Feng
    2006, 34(5):  115-121. 
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    In order to investigate the mechanism of non-axisymmetric spinning and provide accordance for the corre-sponding parameter optimization and process design,a finite-element analytical(FEA)model is established based on the 3 D elastic·-plastic theory to numerically simulate the neck·-spinning process of oblique tubes by the FEA MSC.MARC software.The characteristics of metal flow and the distributions of the stress and the strain in the onepath spinning aye then obtained,and the potential defects and defect areas in the spinning are forecasted.Both the simulative and the experimental results show that the distributions of the deformed mesh,the stress,the strain and the thickness of the workpiece are all asymmetric due to the oblique spinning,that the distributions of the principal stresses and strains in the circumferential direction are sinusoidal or cosinoidal functions,and that,in the spinning,severe thinning occurs near the initial spinning area due to the leaning of workpiece towards the zero region,that is,the dangerous region where breaking may occur.

    Vibration Response of Transmission System of Helical Gear Manufactured by W arm Compaction Powder M etallurgy
    Zhou Zhao-yao Xie Hai-dong Xia Wei
    2006, 34(5):  122-126. 
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    The helical gears manufactured by WaDTI compaction powder metallurgy are of good wearability and low cost.This paper first proposes an integrated dynamic model based on the finite element method,in which the gear pair,the transmission shaft,the bearing and the gearbox are all taken into consideration.By using the finite-ele-ment analyzing software MSC.Nastran.che vibration response of the transmission system of powder metallurgy helical gear with dynamic excitation is then calculated,and the results are compared with those of 38 CrMoAI gear sys-tem.Vibration experiments are finally caried out to verify the correctness of the proposed model.By the abovementioned work,a~undation for the design of transmission system with powder metallurgy helical gears is thus laid.

    Biological Engineering
    Enhancement of Anaerobic Granulation for Sludge by Continuously Adding Bioflocculan
    Wang Jing-song Hu Yong-you Wu Chun-de
    2006, 34(5):  26-32. 
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    Upflow anaerobic sludge blanket(UASB)reactors were operated at(35±1)℃ for 102 days to re-veal the effect of bioflocculant on the anaerobic granulation of sludge during the treatment of low-strength wastewater.The results indicate that the addition of bioflocculant or cationic polyacrylamide(PAM)markedly accelerates the anaerobic granulation,that Reactor 1(R1)with the addition of bioflocculant is of all organic loading rate(OLR)of 3.8g/(L·d)(calculated as the loading of COD on the reactor per liter per day)in 43 days,while Reactor 2(R2)with the addition of cationic PAM and the control reactor 3(R3)reach the same value respectively in 44 and 98 days,that the granules developed in R1 exhibit better settleability and methano.genic activity than those in R2,and that the COD removal efficiencies of R1，,R2 and R3 respectively reach 94.5% ,91.7% and 84.0% when the experiments have been finished.

    Production of Ethanol by Fermentation of Xylose Using Candida sp.
    Lin Ying Zhang Ju-bao Xiang Zhu-fang
    2006, 34(5):  33-37. 
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    Ethanol was produced by the fermentation of xylose using Candida sp.1 779A, and the effects of the aeration level,the initial substrate pH value and the xylose mass concentration on the fermentation were investiga.ted.The results indicate that,when the temperature and the rotating speed are kept constant respectively at 30℃ and 150 r/rain,the fermentation should be carried out in a semi．aerobic condition，with an initia1 pH value 0f 5.0.an optimal xylose content of 60 g/L and a maximum conversion rate of 62.1% .Moreover.a glucose efect on the fermentation is revealed- the ethanol yield from the mixed sugars with a glucose/xylose mass ratio of 3:1 is 57. 6% higher than that from xylose only.

    Growth and M etabolism Characteristics of Panax Cells in Bioreactor
    Wu Zhen-qiang Teng Wei-lan Kwong C Wu Jian-yong
    2006, 34(5):  38-42. 
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    This paper deals with the growth and metabolism characteristics of Panax ginseng cells in a 2.4-L stirring tank bioreactor.The results show that the duration of the 3 phases during the culture of cell suspension is related to the inoculum size,the initial nutrient concentration,the feeding of nutrients and the culture conditions such as tern.perature and dissolved oxygen,that the maximum cell yield reaches about 1 2 g/L for batch culture or 35 g/L for fed.batch culture in dry weight,that the saponin content of ceils quicklY increases in the bloom phase and keeps on in.creasing until the early stage of the declining phase,with a maximum saponin content of about 60～70 g/kg in dry weight,that the conductance value of cell suspension decreases from more than 8000 μS to less than 600 μS with the growth of cells,but increases when the cells autolyze,and that part of cells turns red in the later culture.which has no apparent effect on the saponin content.It thus concluded that the conductance can be used as one of the factors to estimate the growing state and can help guide the controlling and ending of the cuhure.Moreover,he harvest time of cells should be controlled in the early stage of the declining phase.

    Agrobacterium tumefaciens-Mediated Genetic Transformation of Roselle Cell
    Xie Xiu-zhen Lin Qiao-hui Guo Cheng-shuan Guo Yong
    2006, 34(5):  43-47,52. 
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    By using Agrobacterium tumefaciens strains LBA4404 and EHA 105 as the donor strains.the cotyledon and hypocotyl of sterile seedling of roselle as the recipient materials.the basic conditions for the genetic transforma.tion of Roselle cell in vitro were investigated.Then a high-efficiency genetic transformation system was established ,by which two transgenic Roselle cell lines that stably express the activity of neomycin phosphotI_ans rase Ⅱ were ob tained.The results of β-glucuronidase histochemical assay and PC R amplification demonstrate that the overall trans-form ation rate of the explant reaches 29.4% ,and that,as compared with the strain of EHA105.the strain of LBA4404 is more suitable for the transform ation of Roselle explants because no acetosyringone is needed

    Optimized Conditions for Producing Epothilone via Fermentation of Sorangium cellulosum
    Luo Li-xin Wang Wei Lu Yi-ming Pan Li Sa Si-lin Kong Jun-wen
    2006, 34(5):  48-52. 
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    This paper focuses on the production of epothilone,a kind of secondary anti-cancer metabolite fermented by Sorangium cellulosum DSM 11999.The results show that,respectively with potato starch and peptone as the car bon source and the nitrogen source,and with the addition of MnCl4,EDTA-Fe-Na,K2HPO4 ,ZnCl2,CuSO4 and growth factor alanine,epothilone can be produced via the fermentation of Sorangium cellulosum DSM1 1999 in the late exponential phase at 25 oC ．with a yield increased by 22.5% .

    Inhibition of Tyrosinase Activity by Vanillin
    Gong Sheng-zhao Yang Zhuo-ru Cheng Jiang
    2006, 34(5):  53-57. 
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    The inhibitory effect of vanillin on the activities of monophenolase and diphenolase contained in tyrosinase was studied by means of the enzymological kinetic method in a Na2HPO4-NaH2 PO4 buffer solution with pH 6.8 at 25 ℃.The results show that the activities of both monophenolase and diphenolase are inhibited by vanillin.with the vanillin concentration leading to 50% of inhibitmy rate(IC5o)respectively being 2.7 and 4.1 mmol/L,that vanillin extends the lag time of monophenolase for oxidation from 1.1 to 3 min in a vanillin concentration of 4 mmol/L.and that the inhibitory efect of vanillin on diphenolase is in a mixed mode.which is proved by Lineweaver-Burk plots.Moreover,the inhibiting constants for the inhibitor binding with free enzyme and enzyme—substrate complex are respectively 3.48 and 15.1 mmo1/L.

    Biology Science
    Efect of Augmenter of Liver Regeneration on Na+，K+-ATPase Activity of HepG2 Cell
    Lin Ying Tong Ming-hua Kong Xiang-ping Liang Shi-zhong
    2006, 34(5):  58-62. 
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    The effect of recombinant augmenter of liver regeneration(ALR)on the proliferation of HepG2 cell was investigated by the MTY(Thiazolyl blue)assay,and the activity of the Na ,K -ATPase was measured by an in-organic phosphorus spectrophotometer.Then,the phosphorylation of Na+,K+-ATPase was discussed by means of protein immunoblot.The results show that recombinant ALR promotes the proliferation of HepG2 cell in vitro.As for the mechanism.the stimulation of Na+,K+-ATPase in HepG2 cell caused by ALR accords with the Michaelis-Menten equation model.Moreover,ALR improves the turnover rate of Na+,K+-ATPase-the value of Vmax increases from(0.84±0.11)μmol/(mg·min)to(1.68±0.07)μmol/(mg·min)(P<0.01)and that of Km decreases from(23.54±0.12)mmol/L to(20.86±0.13)mmol/L(P>0.05).Also,the resuhs demonstrate that the phosphorylation of serine or threonine is key to the stimulation of Na+,K+-ATPase.A dose-time dependence of the phosphorylation of Na+,K+-ATPase in HepG2 cell stimulated by ALR is finally revealed by means of protein im-munoblot.

    Biological Engineering
    Efect of CpG DNA on CD4+ and CD8+ T Lymphocyte Subpopulations in Blood of Newborn Piglet
    Zhang Ling-hua Guo Yong Tian Xing-shan Zhou Feng-zheng
    2006, 34(5):  63-67. 
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    The effect of immunostimulatory CpG 0lig0de0 ynucle0tides(CpG ODN)on CD4 and CD8 T lympho-cyte subpopulations in the blood of newborn piglets was investigated with or without pseudorabies attenuated(PSA) vaccine．Experimental results suggest that the CD4+ /CD8+ ratio decreases with the age of newbom pigs inoculated with the vaccine only，but keeps steady in pigs treated with CpG ODN and PSA vaccine(P>0．05)，that CpG ODN can effectively prevent the decrease in the proportion of CIM T cell caused by PSA vaccine，and that high titer of PSA specific antibody can be tested in the serum of newborn piglets immunized by both PSA vaccine and CpG ODN(P<0．05)．All these indicate that CpG ODN can greatly enhance the immune response of animals．

    Enzymatic Transesteri6catiOn of Waste Oil Under Ultrasonic Irradiation
    Wu Hong zong Min-hua Lou Wen-yong Chen Zhi-fen
    2006, 34(5):  68-71. 
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    Aiming at the Novozym 435-catalyzed transesteri cation of waste oil in a solvent-free system under ultra.sonic irradiation.the effects of ultrasonic power and radiation mode on the reaction rate and the operation stability were investigated.It is found that the reaction rate of Novozym 435.catalyzed transesterification of waste oiL is remarkably accelerated by pretreatment of enzyme with uhrasonic irradiation at 20 kHz.80 W for 30 min.and that Novozym 435 pretreated with uhrasonic irradiation is of good operation stability because its activity weakens little even after 10 batch operations.

    Biology Science
    Stability of Basic Fibroblast Growth Factor with Acid-Induced Site-Directed Mctor with Am ino tation
    Xie Qiu-ling Zhang Ling Hong An
    2006, 34(5):  72-75,126. 
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    In order to improve the stability of basic fibroblast growth factor(bFGF)in vitro,the bioactivity,the heparin affinity,the aggregation degree and the corresponding aggregation component in wild human bFGF (hb FGF)and its mutant whose Cys78 and Cys 96 mutated to Ser were analyzed and compared,followed by the investi-gation into the electrostatic potential distribution and the solvent.accessible surface area of two bFGF protein mono.mers.The results indicate that the bioactivity and heparin afinity of the mutated hbFGF keep constant while the aggregation degree of the mutated bFGF in vitro decreases although the electrostatic potential distribution and solvent.accessible surface area of hbFGF mutant dimer are similar to those of wild hbFGF dimer.All these reveal that the Cys78 and Cys 96 mutation plays an important role in the covalent interaction of hbFGF but has no obvious
    effect on the non.covalent interaction.

    Biological Engineering
    Stability of Potential Probiotic Lactobacillus rhamnosus in Soy Cheese
    Liu Dong-mei Li Li Liang Shi-zhong Yang Xiao-quan
    2006, 34(5):  76-80. 
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    The incubation conditions of LaetobaciUus rhamnosus 6013 in MRS broth were investigated and the stability of the strain in the pmcessing of soy cheese was evaluated.An anaerobical incubation at 37 ℃ for 48 h was then determined as the optimal condition for the culture of the strain.in which excellent inhibitory efect of the culture supernatant on Staphylococcus aureus,Bacillus cereus and Salmonella typhimurium was revealed.Then,a bacterium-fermented soy cheese was prepared from soy milk treated with bacterial starter cultures(DH1,GH4)and L.rhamnosus 6013.It is found that the viable count of the strain reaches 108 ~109 CFU/mL after ferm entati0n for 6h,that the pH value slightly decreases and the viable count achieves 107 CFU/g after storage at 10℃for 30 days, while the viable counts of DH l and GH4 are all 106CFU/g, and that,when the NaCl content of brine is 20.00~40.oo g/L，little efect of L．rhamnosus 6013 on the survivability is observed．A1l these indicate that the potential probiotic strain L．rhamnosus 6013 can withstand the processing of soy cheese and has no negative effect on the ferm entation of soy cheese．

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