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Sample records for optimized liquid culture

  1. Optimization of liquid overlay technique to formulate heterogenic 3D co-cultures models.

    Science.gov (United States)

    Costa, Elisabete C; Gaspar, Vítor M; Coutinho, Paula; Correia, Ilídio J

    2014-08-01

    Three-dimensional (3D) cell culture models of solid tumors are currently having a tremendous impact in the in vitro screening of candidate anti-tumoral therapies. These 3D models provide more reliable results than those provided by standard 2D in vitro cell cultures. However, 3D manufacturing techniques need to be further optimized in order to increase the robustness of these models and provide data that can be properly correlated with the in vivo situation. Therefore, in the present study the parameters used for producing multicellular tumor spheroids (MCTS) by liquid overlay technique (LOT) were optimized in order to produce heterogeneous cellular agglomerates comprised of cancer cells and stromal cells, during long periods. Spheroids were produced under highly controlled conditions, namely: (i) agarose coatings; (ii) horizontal stirring, and (iii) a known initial cell number. The simultaneous optimization of these parameters promoted the assembly of 3D characteristic cellular organization similar to that found in the in vivo solid tumors. Such improvements in the LOT technique promoted the assembly of highly reproducible, individual 3D spheroids, with a low cost of production and that can be used for future in vitro drug screening assays.

  2. Medium Optimization for Exopolysaccharide Production in Liquid Culture of Endophytic Fungus Berkleasmium sp. Dzf12

    Directory of Open Access Journals (Sweden)

    Peiqin Li

    2012-09-01

    Full Text Available Berkleasmium sp. Dzf12, an endophytic fungus from Dioscorea zingiberensis, is a high producer of spirobisnaphthalenes with various bioactivities. The exopolysaccharide (EPS produced by this fungus also shows excellent antioxidant activity. In this study, the experimental designs based on statistics were employed to evaluate and optimize the medium for EPS production in liquid culture of Berkleasmium sp. Dzf12. For increasing EPS yield, the concentrations of glucose, peptone, KH2PO4, MgSO4∙7H2O and FeSO4∙7H2O in medium were optimized using response surface methodology (RSM. Both the fractional factorial design (FFD and central composite design (CCD were applied to optimize the main factors which significantly affected EPS production. The concentrations of glucose, peptone and MgSO4∙7H2O were found to be the main effective factors for EPS production by FFD experimental analysis. Based on the further CCD optimization and RSM analysis, a quadratic polynomial regression equation was derived from the EPS yield and three variables. Statistical analysis showed the polynomial regression model was in good agreement with the experimental results with the determination coefficient (adj-R2 as 0.9434. By solving the quadratic regression equation, the optimal concentrations of glucose, peptone and MgSO4∙7H2O for EPS production were determined as 63.80, 20.76 and 2.74 g/L, respectively. Under the optimum conditions, the predicted EPS yield reached the maximum (13.22 g/L. Verification experiment confirmed the validity with the actual EPS yield as 13.97 g/L, which was 6.29-fold in comparison with that (2.22 g/L in the original basal medium. The results provide the support data for EPS production in large scale and also speed up the application of Berkleasmium sp. Dzf12.

  3. Optimization of liquid culture conditions of Philippine wild edible mushrooms as potential source of bioactive lipids

    Science.gov (United States)

    With remarkable bioactivities and delightful taste, mushrooms have been a commercial nutraceutical around the world. Mushrooms are cultivated on solid materials. Here we report the successful cultivation of four Philippine edible mushrooms in liquid medium. This work highlights the optimal liquid cu...

  4. Production of fosmid genomic libraries optimized for liquid culture recombineering and cross-species transgenesis.

    Science.gov (United States)

    Ejsmont, Radoslaw Kamil; Bogdanzaliewa, Maria; Lipinski, Kamil Andrzej; Tomancak, Pavel

    2011-01-01

    Genomic DNA libraries are a valuable source of large constructs that can contain all the regulatory elements necessary for recapitulating wild-type gene expression when introduced into animal genomes as a transgene. Such clones can be directly used in complementation studies. In combination with recombineering manipulation, the tagged genomic clones can serve as faithful in vivo gene activity reporters that enable studies of tissue specificity of gene expression, subcellular protein localization, and affinity purification of complexes. We present a detailed protocol for generating an unbiased genomic library in a custom pFlyFos vector that is optimized for liquid culture recombineering manipulation and site-specific transgenesis of fosmid-size loci across different Drosophila species. The cross-species properties of the library can be used, for example, to establish the specificity of RNAi phenotypes or to selectively introgress specific genomic loci among different Drosophila species making it an ideal tool for experimental evolutionary studies. The FlyFos system can be easily adapted to other organisms.

  5. Optimization of Large-Scale Culture Conditions for the Production of Cordycepin with Cordyceps militaris by Liquid Static Culture

    Directory of Open Access Journals (Sweden)

    Chao Kang

    2014-01-01

    Full Text Available Cordycepin is one of the most important bioactive compounds produced by species of Cordyceps sensu lato, but it is hard to produce large amounts of this substance in industrial production. In this work, single factor design, Plackett-Burman design, and central composite design were employed to establish the key factors and identify optimal culture conditions which improved cordycepin production. Using these culture conditions, a maximum production of cordycepin was 2008.48 mg/L for 700 mL working volume in the 1000 mL glass jars and total content of cordycepin reached 1405.94 mg/bottle. This method provides an effective way for increasing the cordycepin production at a large scale. The strategies used in this study could have a wide application in other fermentation processes.

  6. Optimization of Large-Scale Culture Conditions for the Production of Cordycepin with Cordyceps militaris by Liquid Static Culture

    Science.gov (United States)

    Kang, Chao; Wen, Ting-Chi; Kang, Ji-Chuan; Meng, Ze-Bing; Li, Guang-Rong; Hyde, Kevin D.

    2014-01-01

    Cordycepin is one of the most important bioactive compounds produced by species of Cordyceps sensu lato, but it is hard to produce large amounts of this substance in industrial production. In this work, single factor design, Plackett-Burman design, and central composite design were employed to establish the key factors and identify optimal culture conditions which improved cordycepin production. Using these culture conditions, a maximum production of cordycepin was 2008.48 mg/L for 700 mL working volume in the 1000 mL glass jars and total content of cordycepin reached 1405.94 mg/bottle. This method provides an effective way for increasing the cordycepin production at a large scale. The strategies used in this study could have a wide application in other fermentation processes. PMID:25054182

  7. A novel liquid medium for the efficient growth of the salmonid pathogen Piscirickettsia salmonis and optimization of culture conditions.

    Science.gov (United States)

    Henríquez, Mirtha; González, Ernesto; Marshall, Sergio H; Henríquez, Vitalia; Gómez, Fernando A; Martínez, Irene; Altamirano, Claudia

    2013-01-01

    Piscirickettsia salmonis is the bacterium that causes Piscirickettsiosis, a systemic disease of salmonid fish responsible for significant economic losses within the aquaculture industry worldwide. The growth of the bacterium for vaccine formulation has been traditionally accomplished by infecting eukaryotic cell lines, a process that involves high production costs and is time-consuming. Recent research has demonstrated that it is possible to culture pure P. salmonis in a blood containing (cell-free) medium. In the present work we demonstrate the growth of P. salmonis in a liquid medium free from blood and serum components, thus establishing a novel and simplified bacteriological medium. Additionally, the new media reported provides improved growth conditions for P. salmonis, where biomass concentrations of approximately 800 mg cell dry weight L(-1) were obtained, about eight times higher than those reported for the blood containing medium. A 2- level full factorial design was employed to evaluate the significance of the main medium components on cell growth and an optimal temperature range of 23-27°C was determined for the microorganism to grow in the novel liquid media. Therefore, these results represent a breakthrough regarding P. salmonis research in order to optimize pure P. salmonis growth in liquid blood and serum free medium.

  8. A novel liquid medium for the efficient growth of the salmonid pathogen Piscirickettsia salmonis and optimization of culture conditions.

    Directory of Open Access Journals (Sweden)

    Mirtha Henríquez

    Full Text Available Piscirickettsia salmonis is the bacterium that causes Piscirickettsiosis, a systemic disease of salmonid fish responsible for significant economic losses within the aquaculture industry worldwide. The growth of the bacterium for vaccine formulation has been traditionally accomplished by infecting eukaryotic cell lines, a process that involves high production costs and is time-consuming. Recent research has demonstrated that it is possible to culture pure P. salmonis in a blood containing (cell-free medium. In the present work we demonstrate the growth of P. salmonis in a liquid medium free from blood and serum components, thus establishing a novel and simplified bacteriological medium. Additionally, the new media reported provides improved growth conditions for P. salmonis, where biomass concentrations of approximately 800 mg cell dry weight L(-1 were obtained, about eight times higher than those reported for the blood containing medium. A 2- level full factorial design was employed to evaluate the significance of the main medium components on cell growth and an optimal temperature range of 23-27°C was determined for the microorganism to grow in the novel liquid media. Therefore, these results represent a breakthrough regarding P. salmonis research in order to optimize pure P. salmonis growth in liquid blood and serum free medium.

  9. Optimization of the Liquid Culture Medium Composition to Obtain the Mycelium of Agaricus bisporus Rich in Essential Minerals.

    Science.gov (United States)

    Krakowska, Agata; Reczyński, Witold; Muszyńska, Bożena

    2016-09-01

    Agaricus bisporus species (J.E. Lange) Imbach one of the most popular Basidiomycota species was chosen for the research because of its dietary and medicinal value. The presented herein studies included determination of essential mineral accumulation level in the mycelium of A. bisporus, cultivated on liquid cultures in the medium supplemented with addition of the chosen metals' salts. Quantitative analyses of Zn, Cu, Mg, and Fe in liquid cultures made it possible to determine the relationship between accumulation of the selected mineral in A. bisporus mycelium and the culture conditions. Monitoring of the liquid cultures and determination of the elements' concentrations in mycelium of A. bisporus were performed using the flame technique of AAS method. Concentration of Zn in the mycelium, maintained in the medium with the addition of its salt, was in a very wide range from 95.9 to 4462.0 mg/g DW. In the analyzed A. bisporus mycelium, cultured in the medium enriched with copper salt, this metal concentration changed from 89.79 to 7491.50 mg/g DW; considering Mg in liquid cultured mycelium (medium with Mg addition), its concentration has changed from 0.32 to 10.55 mg/g DW. The medium enriched with iron salts has led to bioaccumulation of Fe in mycelia of A. bisporus. Determined Fe concentration was in the range from 0.62 to 161.28 mg/g DW. The proposed method of liquid A. bisporus culturing on medium enriched with the selected macro- and microelements in proper concentrations ratio have led to obtaining maximal growth of biomass, characterized by high efficiency of the mineral accumulation. As a result, a dietary component of increased nutritive value was obtained.

  10. Optimization of Fermentation Condition of Yeast Culture

    Institute of Scientific and Technical Information of China (English)

    WANG Qiuju; XU Li; CUI Yizhe

    2008-01-01

    Culture condition of every phase for fermentation of yeast culture was studied, and its solid and liquid conditions of elaboration were optimized to improve the total counts of living cells.Results showed that microzyme grew best at 30℃ when solid fermented,and the count of the living cells reached the tiptop with pH 5.5.The count of Candida tropicalis could reach 137.96×109 cfu·g-1,the count of Saccharomyces cerevisia could reach 134.62×109 cfu·g-1;the best liquid fermentation condition for cell-wall broken was 50℃ for 28 h,the rate of cell-wall broken could reach 80% at least;the rate of vitamin loss in yeast could be the minimun, the loss rate of vitamin B1 in Candida tropicalis and Saccharomyces cerevisiae was 8.71% and 19.54% respectively, the loss rate of vitamin B2 was 19.39% and 13.18%,respectively,and the loss rate of vitamin B6 was 6.3% and 3.04%,respectively.

  11. MARKOV CHAIN PORTFOLIO LIQUIDITY OPTIMIZATION MODEL

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    Eder Oliveira Abensur

    2014-05-01

    Full Text Available The international financial crisis of September 2008 and May 2010 showed the importance of liquidity as an attribute to be considered in portfolio decisions. This study proposes an optimization model based on available public data, using Markov chain and Genetic Algorithms concepts as it considers the classic duality of risk versus return and incorporating liquidity costs. The work intends to propose a multi-criterion non-linear optimization model using liquidity based on a Markov chain. The non-linear model was tested using Genetic Algorithms with twenty five Brazilian stocks from 2007 to 2009. The results suggest that this is an innovative development methodology and useful for developing an efficient and realistic financial portfolio, as it considers many attributes such as risk, return and liquidity.

  12. Optimization and radiation protection culture

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, In Young; Shin, Hyeong Ki; Lee, Chan Mi [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-04-15

    Safety culture or radiation protection culture is based in common on the term, 'culture'. Culture is defined as the learned, shared set of symbols and patterns of basic assumptions, which is invented, discovered, or developed by a given group as it learns to cope with its problem of external adaptation and internal integration. Safety culture generally refers to the attitude and behaviors affecting safety performance. The concept of 'Safety Culture' was introduced after the Chernobyl accident in 1986. For the accident, nuclear society reached the conclusion that the cause was the wrong management attitude of the NPP, that is, deficient 'Safety Culture'. Recently, 'Radiation Protection Culture' was introduced as the core concept of nuclear safety culture. There have been many efforts to establish definition and develop assessment tool for radiation protection culture in international level such as ICRP and IRPA as well as NRC. In the same context with the safety culture, radiation protection culture is defined as 'the core values and behaviors resulting from a collective commitment by leaders and individual's to emphasize safety over competing goals to ensure protection of people and the environment.' It is worthwhile to recognize that regulatory enforcement in establishing healthy radiation protection culture of operators should be minimized because culture is not in the domain of regulatory enforcement. However, as 'ALARA', the most important concept in radiation protection, may be successfully achieved only in well established radiation protection culture, the least regulatory intervention would be needed in promoting and nurturing radiation protection culture in licensee. In addition, the concept of radiation protection culture should be addressed in plant operational policy to achieve the goals of ALARA. The pre-condition of the successful radiation protection culture is a healthy organizational

  13. Optimization of culture conditions of Lactobacillus plantarum using cassava lees liquid%利用木薯酒糟液培养植物乳杆菌工艺条件的优化研究

    Institute of Scientific and Technical Information of China (English)

    柳树海; 陈瑾; 梅雪臣; 刘晓红; 缪礼鸿

    2013-01-01

    Increasing the viable bacteria counts of lactic acid bacteria in the medium and cutting down cost of medium production were the key of developing feeding lactic acid bacteria agent. The fermentation medium and fermentation parameters of Lactobacillus plantarum cultured in cassava lees liquid were optimized by single factor and orthogonal experiment method. The results showed that the optimum medium of Lactobacillus plantarum including cassava lees liquid 97. 75%, molasses 2%, yeast extract 0. 25%, pH5. 5 and the optimum fermentation parameters were shake cultivation at 7℃, 120 r/min for 24 h. In the end of culture, viable bacteria counts of Lactobacillus plantarum was up to 49. 0×108 cfu/ml, which was 2. 41 times of that before optimizing, and 35% higher than in the MRS medium. The results showed that it was feasible to culture Lactobacillus plantarum using cassava lees liquid.%提高培养基中乳酸菌活菌数和降低培养基生产成本是开发饲用乳酸菌剂的关键.本研究以木薯酒糟液作为培养植物乳杆菌的基础发酵培养基,通过单因子和正交试验方法,对木薯酒糟培养乳酸菌的培养基配方及发酵条件进行了优化.结果表明:植物乳杆菌最佳培养基配方为木薯酒糟液97.75%,糖蜜2.00%,酵母膏0.25%,pH值5.5.最佳培养条件为在37℃下用120 r/min摇床培养,培养时间为24 h.培养结束后培养液中乳酸菌菌体活菌数达49.0×108 cfu/ml,是未优化木薯酒糟液基础发酵培养基中活菌数的2.41倍,比MRS培养基中的活菌数高35%.表明用优化的木薯酒糟液培养基培养植物乳杆菌具有可行性.

  14. Comparison of liquid culture methods and effect of temporary

    African Journals Online (AJOL)

    star-pc

    2012-04-24

    Apr 24, 2012 ... Four different liquids, as well as solid culture methods used in shoot propagation of banana were .... forms of liquid medium application on the increase in dry matter in ... manual cutting, (2) Automation through use of liquid.

  15. [Method of producing fusarin C in perlite-liquid culture medium].

    Science.gov (United States)

    Li, G; Li, M; Ma, J

    1992-02-01

    For researching the biosynthesis labelled Fusarin C(Fc) by Fuscarium moniliforme, a more quick and convenient method of Fusarin C production and purification were established, and a good liquid culture medium consisted of different kinds organic matters (hydroxy proline, sucrose and glycerin), inorganic salts and perlite replaced corn grit medium. The perlite-liquid culture medium inoculated with the strain of F. moniliforme yields 936mg Fc/kg organic matter with in 14 days of incubation at 28 degrees C. As compared with the corn grit medium, the amount of Fc from perlite-liquid medium was more than that from corn grit medium (831mg Fc/kg corn grit). In all experiments both thin-layer chromatography and high-pressure liquid chromatography were used to confirm the presence of Fc. parameters which were important for the optimal biosynthesis of Fc included hydroxy proline and sucrose concentrations, incubated time/temperature and amount of perlite. The 40g of sucrose/L liquid culture was optimal concentration for Fusarin C production. Of three contained N-matter tested, hydroxy proline was the best sources of N-atom for Fusarin C. Under the absence of hydroxy proline, the Fc wasn't synthesized in perlite-liquid culture medium by F. moniliforme. A culture time/temperature study of Fc production was done, and the optimal Fc amounts was synthesized after incubation for 14 days at 28 degrees C on perlite-liquid culture medium.

  16. CELLULASES FROM THE BASIDIO - MYCETES CULTURAL LIQUID

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    К. G. Dreval

    2013-04-01

    Full Text Available Adsorption of cellulases on substrate taking place during the cultivation process was determined. Adsorbed enzymes can be eluted by buffer solution with high ionic strength, but for determine their activity they should be transferred into the aqueous solution. On the basis of the results a method for obtaining of cellulases preparations from cultural liquids of basidiomycetes was developed. This method is the elution of cellulases from the cultivation substrate of basidiomycetes. It was found that using of the last allows to obtain enzymatic preparations with a high degree of purification in 3 stages (salting out of proteins — dialysis — gelchromatography. Cellulase preparations received original products of basidiomycetes strains К-1, А-Дон-02, Д-1 Irpex lacteus and AnSc-1 Daedaleopsis confragosa f. confragosa were obtained. They contained different proteins, enzymes with specific peaks out of column and their activity. However, common to them was a distinct maximum of outing from the column by endoglucanases or cellobiases, which may indicate that the studied cellulolytic complexes of basidiomycetes do not contain multiple forms of cellulases with different molecular mass. This method allowed to obtain preparations with different degree of purification in comparing with the original culture filtrate 7,3 for endoglucanase and 33,3 for cellobiase of strain А-Дон-02 I. lacteus; 13,1 for endoglucanase and 25,5 for cellobiase of strain Д-1 I. lacteus; 29,9 for endoglucanase and 90,1 for cellobiase of strain К-1 I. lacteus; 2,1 for endoglucanase and 30,6 for cellobiase of strain AnSc-1 D. confragosa f. confragosa.

  17. Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

    Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated. Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid memb...

  18. Optimized liquid-liquid extractive rerefining of spent lubricants.

    Science.gov (United States)

    Kamal, Muhammad Ashraf; Naqvi, Syed Mumtaz Danish; Khan, Fasihullah

    2014-01-01

    Central composite design methodology has been employed to model the sludge yield data obtained during liquid-liquid extractive rerefining of spent lubricants using an alcohol (1-butanol) and a ketone (methyl ethyl ketone) as prospective solvents. The study has resulted in two reasonably accurate multivariate process models that relate the sludge yield (R (2) = 0.9065 and 0.9072 for alcohol and ketone, resp.) to process variables (settling time t, operating temperature T, and oil to solvent ratio r). Construction of such models has allowed the maximization of the sludge yield (more than 8% and 3% in case of alcohol and ketone, resp.) so that the extraction of useable oil components from spent lubricants can economically be performed under extremely mild conditions (t = 16.7 h, T = 10°C, and r = 2) and fairly moderate conditions (t = 26.6 h, T = 10°C, and r = 5) established for the alcohol and ketone correspondingly. Based on these performance parameters alcohol appears to be superior over ketone for this extraction process. Additionally extractive treatment results in oil stocks with lesser quantity of environmentally hazardous polyaromatic hydrocarbons that are largely left in the separated sludge.

  19. Optimized Liquid-Liquid Extractive Rerefining of Spent Lubricants

    Directory of Open Access Journals (Sweden)

    Muhammad Ashraf Kamal

    2014-01-01

    Full Text Available Central composite design methodology has been employed to model the sludge yield data obtained during liquid-liquid extractive rerefining of spent lubricants using an alcohol (1-butanol and a ketone (methyl ethyl ketone as prospective solvents. The study has resulted in two reasonably accurate multivariate process models that relate the sludge yield (R2=0.9065 and 0.9072 for alcohol and ketone, resp. to process variables (settling time t, operating temperature T, and oil to solvent ratio r. Construction of such models has allowed the maximization of the sludge yield (more than 8% and 3% in case of alcohol and ketone, resp. so that the extraction of useable oil components from spent lubricants can economically be performed under extremely mild conditions (t = 16.7 h, T=10°C, and r=2 and fairly moderate conditions (t = 26.6 h, T=10°C, and r=5 established for the alcohol and ketone correspondingly. Based on these performance parameters alcohol appears to be superior over ketone for this extraction process. Additionally extractive treatment results in oil stocks with lesser quantity of environmentally hazardous polyaromatic hydrocarbons that are largely left in the separated sludge.

  20. Optimized determination of polybrominated diphenyl ethers by ultrasound-assisted liquid-liquid extraction and high-performance liquid chromatography.

    Science.gov (United States)

    He, Kuang; Lv, YuanCai; Chen, YuanCai

    2014-10-01

    A method based on ultrasound-assisted liquid-liquid extraction and high-performance liquid chromatography has been optimized for the determination of six polybrominated diphenyl ether congeners. The optimal condition relevant to the extraction was first investigated, more than 98.7 ± 0.7% recovery was achieved with dichloromethane as extractant, 5 min extraction time, and three cycles of ultrasound-assisted liquid-liquid extraction. Then multiple function was employed to optimize polybrominated diphenyl ether detection conditions with overall resolution and chromatography signal area as the responses. The condition chosen in this experiment was methanol/water 93:7 v/v, flow rate 0.80 mL/min, column temperature 30.0°C. The optimized technique revealed good linearity (R(2) > 0.9962 over a concentration range of 1-100 μg/L) and repeatability (relative standard deviation liquid-liquid extraction coupled with high-performance liquid chromatography was effective to identify and quantify the complex polybrominated diphenyl ethers in effluent samples.

  1. Optimization of Lycopene Extraction from Tomato Cell Suspension Culture by Response Surface Methodology

    OpenAIRE

    Lu, Chi-Hua; Engelmann, Nancy J.; Lila, Mary Ann; Erdman, John W

    2008-01-01

    Radioisotope-labeled lycopene is an important tool for biomedical research but currently is not commercially available. A tomato cell suspension culture system for the production of radioisotope-labeled lycopene was previously developed in our laboratory. In the current study, the goal was to optimize the lycopene extraction efficiency from tomato cell cultures for preparatory high-performance liquid chromatography (HPLC) separation. We employed response surface methodology (RSM), which combi...

  2. Cryogenic Eyesafer Laser Optimization for Use Without Liquid Nitrogen

    Science.gov (United States)

    2014-02-01

    state laser system with an optimum operating temperature somewhat higher—ideally 125–150 K—can be identified, then a Stirling cooler can be used to...liquid cryogens. This calls for optimal performance around 125–150 K—high enough for reasonably efficient operation of a Stirling cooler . We...needed to optimize laser performance in the desired temperature range. This did not include actual use of Stirling coolers , but rather involved both

  3. Optimizing heterosurface adsorbent synthesis for liquid chromatography

    Science.gov (United States)

    Bogoslovskii, S. Yu.; Serdan, A. A.

    2016-03-01

    The structural and geometric parameters of a silica matrix (SM) for the synthesis of heterosurface adsorbents (HAs) are optimized. Modification is performed by shielding the external surfaces of alkyl-modified silica (AS) using human serum albumin and its subsequent crosslinking. The structural and geometric characteristics of the SM, AS, and HA are measured via low-temperature nitrogen adsorption. It is found that the structural characteristics of AS pores with diameters D 9 nm reduces significantly due to adsorption of albumin. It is concluded that silica gel with a maximum pore size distribution close to 5 nm and a minimal proportion of pores with D > 9 nm is optimal for HA synthesis; this allows us to achieve the greatest similarity between the chromatographic retention parameters for HA and AS. The suitability of the synthesized adsorbents for analyzing drugs in biological fluids through direct sample injection is confirmed by chromatography. It was found that the percentage of the protein fraction detected at the outlet of the chromatographic column is 98%.

  4. Optimization of liquid crystal structures for real time holography applications.

    Science.gov (United States)

    Sahraoui, B; Anczykowska, A; Bartkiewicz, S; Mysliwiec, J

    2011-11-21

    In this paper we present results of experiments designed to increase our understanding of the photorefractive effect occurring during processes of dynamic hologram generation in Hybrid Photorefractive Liquid Crystal Structures (HPLCS). We also propose equivalent mathematical model which can be used to optimize those structures in order to obtain the highest diffraction efficiency in possibly shortest time.

  5. Efficiency of neural network-based combinatorial model predicting optimal culture conditions for maximum biomass yields in hairy root cultures.

    Science.gov (United States)

    Mehrotra, Shakti; Prakash, O; Khan, Feroz; Kukreja, A K

    2013-02-01

    KEY MESSAGE : ANN-based combinatorial model is proposed and its efficiency is assessed for the prediction of optimal culture conditions to achieve maximum productivity in a bioprocess in terms of high biomass. A neural network approach is utilized in combination with Hidden Markov concept to assess the optimal values of different environmental factors that result in maximum biomass productivity of cultured tissues after definite culture duration. Five hidden Markov models (HMMs) were derived for five test culture conditions, i.e. pH of liquid growth medium, volume of medium per culture vessel, sucrose concentration (%w/v) in growth medium, nitrate concentration (g/l) in the medium and finally the density of initial inoculum (g fresh weight) per culture vessel and their corresponding fresh weight biomass. The artificial neural network (ANN) model was represented as the function of these five Markov models, and the overall simulation of fresh weight biomass was done with this combinatorial ANN-HMM. The empirical results of Rauwolfia serpentina hairy roots were taken as model and compared with simulated results obtained from pure ANN and ANN-HMMs. The stochastic testing and Cronbach's α-value of pure and combinatorial model revealed more internal consistency and skewed character (0.4635) in histogram of ANN-HMM compared to pure ANN (0.3804). The simulated results for optimal conditions of maximum fresh weight production obtained from ANN-HMM and ANN model closely resemble the experimentally optimized culture conditions based on which highest fresh weight was obtained. However, only 2.99 % deviation from the experimental values could be observed in the values obtained from combinatorial model when compared to the pure ANN model (5.44 %). This comparison showed 45 % better potential of combinatorial model for the prediction of optimal culture conditions for the best growth of hairy root cultures.

  6. Docetaxel-loaded thermosensitive liquid suppository: optimization of rheological properties.

    Science.gov (United States)

    Yeo, Woo Hyun; Ramasamy, Thiruganesh; Kim, Dong-Wuk; Cho, Hyuk Jun; Kim, Yong-Il; Cho, Kwan Hyung; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2013-12-01

    The main purpose of this work was to optimize the rheological properties of docetaxel (DCT)-loaded thermosensitive liquid suppositories for rectal administration. DCT-loaded liquid suppositories were prepared by a cold method and characterized in terms of physicochemical and viscoelastic properties. Major formulation parameters including poloxamer (P407) and Tween 80 were optimized to adjust the thermogelling and mucoadhesive properties for rectal administration. Notably, the gel strength and mucoadhesive force significantly increased with the increase in these variables. Furthermore, DCT incorporation did not alter the viscoelastic behavior, and the mean particle size of nanomicelles in it was approximately 16 nm with a distinct spherical shape. The formulation existed as liquid at room temperature and transformed into gel at physiological temperature through the reverse gelation phenomenon. Thus, DCT-loaded thermosensitive liquid suppositories [DCT/P407/P188/Tween 80 (0.25/11/15/10 %)] with optimal gel properties were easy to prepare and administer rectally, and might enable the gel to stay in the rectum without getting out from rectum.

  7. Trends in High Performance Liquid Chromatography for Cultural Heritage.

    Science.gov (United States)

    Degano, Ilaria; La Nasa, Jacopo

    2016-04-01

    The separation, detection and quantitation of specific species contained in a sample in the field of Cultural Heritage requires selective, sensitive and reliable methods. Procedures based on liquid chromatography fulfil these requirements and offer a wide range of applicability in terms of analyte types and concentration range. The main applications of High Performance Liquid Chromatography in this field are related to the separation and detection of dyestuffs in archaeological materials and paint samples by reversed-phase liquid chromatography with suitable detectors. The relevant literature will be revised, with particular attention to sample treatment strategies and future developments. Reversed phase chromatography has also recently gained increasing importance in the analysis of lipid binders and lipid materials in archaeological residues: the main advantages and disadvantages of the new approaches will be discussed. Finally, the main applications of ion chromatography and size exclusion chromatography in the field of Cultural Heritage will be revised in this chapter.

  8. Analysis and optimization of Love wave liquid sensors.

    Science.gov (United States)

    Jakoby, B; Vellekoop, M J

    1998-01-01

    Love wave sensors are highly sensitive microacoustic devices, which are well suited for liquid sensing applications thanks to the shear polarization of the wave. The sensing mechanism thereby relies on the mechanical (or acoustic) interaction of the device with the liquid. The successful utilization of Love wave devices for this purpose requires proper shielding to avoid unwanted electric interaction of the liquid with the wave and the transducers. In this work we describe the effects of this electric interaction and the proper design of a shield to prevent it. We present analysis methods, which illustrate the impact of the interaction and which help to obtain an optimized design of the proposed shield. We also present experimental results for devices that have been fabricated according to these design rules.

  9. Optimizing of Culture Conditionin Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionBioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world. 2 Rotating bioreactors2.1 Working principleThere are two kinds of horizontal rotating bioreactor: HARV(high aspect ratio vessel) and RCCS (rotary cell culture system). It is drived by step motor with horizontal rotation, the culture medium and cell is filled between ...

  10. Seed train optimization for cell culture.

    Science.gov (United States)

    Frahm, Björn

    2014-01-01

    For the production of biopharmaceuticals a seed train is required to generate an adequate number of cells for inoculation of the production bioreactor. This seed train is time- and cost-intensive but offers potential for optimization. A method and a protocol are described for the seed train mapping, directed modeling without major effort, and its optimization regarding selected optimization criteria such as optimal points in time for cell passaging. Furthermore, the method can also be applied for the set-up of a new seed train, for example for a new cell line. Although the chapter is directed towards suspension cell lines, the method is also generally applicable, e.g. for adherent cell lines.

  11. Optimal design of porous structures for the fastest liquid absorption.

    Science.gov (United States)

    Shou, Dahua; Ye, Lin; Fan, Jintu; Fu, Kunkun

    2014-01-14

    Porous materials engineered for rapid liquid absorption are useful in many applications, including oil recovery, spacecraft life-support systems, moisture management fabrics, medical wound dressings, and microfluidic devices. Dynamic absorption in capillary tubes and porous media is driven by the capillary pressure, which is inversely proportional to the pore size. On the other hand, the permeability of porous materials scales with the square of the pore size. The dynamic competition between these two superimposed mechanisms for liquid absorption through a heterogeneous porous structure may lead to an overall minimum absorption time. In this work, we explore liquid absorption in two different heterogeneous porous structures [three-dimensional (3D) circular tubes and porous layers], which are composed of two sections with variations in radius/porosity and height. The absorption time to fill the voids of porous constructs is expressed as a function of radius/porosity and height of local sections, and the absorption process does not follow the classic Washburn's law. Under given height and void volume, these two-section structures with a negative gradient of radius/porosity against the absorption direction are shown to have faster absorption rates than control samples with uniform radius/porosity. In particular, optimal structural parameters, including radius/porosity and height, are found that account for the minimum absorption time. The liquid absorption in the optimized porous structure is up to 38% faster than in a control sample. The results obtained can be used a priori for the design of porous structures with excellent liquid management property in various fields.

  12. A protocol for axenic liquid cell cultures of a woody leguminous mangrove, Caesalpinia crista, and their amino acids profiling.

    Science.gov (United States)

    Inoue, Aya; Ogita, Shinjiro; Tsuchiya, Shinpei; Minagawa, Reiko; Sasamoto, Hamako

    2015-05-01

    Callus induction, maintenance and protoplast cultures were achieved from immature seeds of a woody leguminous mangrove, Caesalpinia crista. Axenic cultures were possible during 1.5 months of pod storage in 0.1% benzalkonium chloride solution. Callus induction was achieved using 1 mL liquid medium in a 10 mL flat-bottomed culture tube. Protoplasts were isolated using Cellulase R10, Hemicellulase, and Driselase 20 in 0.6 M mannitol solution and sub-culturable calluses were obtained in 50 μL liquid medium using a 96-microplate method. The optimal hormonal concentration was 10 μM each of 2,4-dichlorophenoxyacetic acid and benzyladenine in liquid Murashige and Skoog's basal medium for both callus induction and maintenance, and protoplast cultures. Similarities and differences in amino acid profiles and culture conditions are discussed among woody mangrove species and non-mangrove leguminous species. Caesalpinia crista cultures were unique as they secreted a large amount of amino acids, including proline, into the liquid culture medium.

  13. A simple and cost effective liquid culture system for the micropropagation of two commercially important apple rootstocks.

    Science.gov (United States)

    Mehta, Mohina; Ram, Raja; Bhattacharya, Amita

    2014-07-01

    The two commercially important apple rootstocks i.e., MM106 and B9 were micropropagated using a liquid culture system. Three different strengths of 0.8% agar solidified PGR free basal MS medium were first tested to optimize the culture media for both the rootstocks. Full strength medium (MS0) supported maximum in vitro growth, multiplication, rooting and survival under field conditions as opposed to quarter and half strength media. When three different volumes of liquid MS0 were tested, highest in vitro growth, multiplication, rooting and also survival under field conditions were achieved in 20 mL liquid MS0. The cost of one litre of liquid medium was also reduced by 8 times to Rs. 6.29 as compared to solid medium. The cost of 20 mL medium was further reduced to Rs. 0.125.

  14. Optimizing settling conditions for treatment of liquid hog manure.

    Science.gov (United States)

    Trias, M; Mortula, M M; Hu, Z; Gagnon, G A

    2004-08-01

    Sedimentation is a widely used separation method for treating agricultural waste. There are several chemical and biological characteristics, which can affect the settling behavior and liquid waste. The optimization of cation balances and potential for nitrification are among these processes. In addition to sedimentation, it can also affect the dewaterability of the samples. Liquid hog manure was used during the laboratory based experiments to investigate the effects of Ca2+ and Mg2+ ions and nitrification inhibition on the overall settling and dewatering characteristics. The results indicated that settling and dewatering characteristics improved during the course of the experiments. However, the improvement in settling and dewatering characteristics was inconsistent and not statistically significant. Cation addition in aerated reactor increased the highest settling velocity (94%). The improvement in dewaterability, as quantified by capillary suction time, was also not consistent. The greatest filterability observed in the supernatant was a capillary suction time of 40 s for a M:D ratio of 2:1. Initial NH 4 + concentration was more important than the nitrification inhibitor, as the presence of nitrification inhibitor increased the nitrification rate by over 300% because of the high initial NH 4 + concentration and low volatile suspended solid. The results from these experiments provide the basis for further field evaluation of cation optimization.

  15. Skull-bound perception and precision optimization through culture.

    Science.gov (United States)

    Paton, Bryan; Skewes, Josh; Frith, Chris; Hohwy, Jakob

    2013-06-01

    Clark acknowledges but resists the indirect mind-world relation inherent in prediction error minimization (PEM). But directness should also be resisted. This creates a puzzle, which calls for reconceptualization of the relation. We suggest that a causal conception captures both aspects. With this conception, aspects of situated cognition, social interaction and culture can be understood as emerging through precision optimization.

  16. Skull-bound perception and precision optimization through culture

    DEFF Research Database (Denmark)

    Paton, Bryan; Skewes, Joshua; Frith, Chris D

    2013-01-01

    Clark acknowledges but resists the indirect mind–world relation inherent in prediction error minimization (PEM). But directness should also be resisted. This creates a puzzle, which calls for reconceptualization of the relation. We suggest that a causal conception captures both aspects. With this....... With this conception, aspects of situated cognition, social interaction and culture can be understood as emerging through precision optimization....

  17. Optimization of Lipase Production by a Rhizopus MR12 in Shake Culture

    Science.gov (United States)

    Kader, R.; Yousuf, A.; Hoq, M. M.

    Rhizopus sp. a mould of mucor family, excrete lipase when cultured on lipolytic media. The Rhizopus sp. produced a larger clear zone on tributyrin agar medium suggesting its esterase activity. It was further investigated in liquid medium in order to optimize the lipase production conditions under shake culture. Lipase production was found to be maximum with medium containing maltose (1%) and peptone (5%) as carbon and nitrogen sources, respectively with Rhizopus sp. The enzyme production was profoundly influenced by initial pH of the medium and optimum value of this parameter was found to be 6.0. Maximum enzyme production was obtained at 30°C with a shaking rate of 200 rpm. Ca2+ was found to stimulate lipase production, while it was strongly inhabited by Hg2+. Lipase production was increased about 23.7% under optimized cultivation conditions over olive oil-peptone medium.

  18. Blade Shape Optimization of Liquid Turbine Flow Sensor

    Institute of Scientific and Technical Information of China (English)

    郭素娜; 张涛; 孙立军; 杨振; 杨文量

    2016-01-01

    Based on the characteristic curve analysis, the method using 2D(K ) square difference of meter factor at different flow rates was developed to evaluate the performance of turbine flow sensor in this study. Then according to the distribution of entrance velocity, it was supposed that reducing the blade area near the tip could decrease the linearity error of a sensor. Therefore, the influence of different blade shape parameters on the performance of the sensor was investigated by combining computational fluid dynamics(CFD)simulation with experimental test. The experimental results showed that, for the liquid turbine flow sensor with a diameter of 10 mm, the linearity error was smallest, and the performance of sensor was optimal when blade shape parameter equaled 0.25.

  19. Optimization to the Culture Conditions for Phellinus Production with Regression Analysis and Gene-Set Based Genetic Algorithm.

    Science.gov (United States)

    Li, Zhongwei; Xin, Yuezhen; Wang, Xun; Sun, Beibei; Xia, Shengyu; Li, Hui; Zhu, Hu

    2016-01-01

    Phellinus is a kind of fungus and is known as one of the elemental components in drugs to avoid cancers. With the purpose of finding optimized culture conditions for Phellinus production in the laboratory, plenty of experiments focusing on single factor were operated and large scale of experimental data were generated. In this work, we use the data collected from experiments for regression analysis, and then a mathematical model of predicting Phellinus production is achieved. Subsequently, a gene-set based genetic algorithm is developed to optimize the values of parameters involved in culture conditions, including inoculum size, PH value, initial liquid volume, temperature, seed age, fermentation time, and rotation speed. These optimized values of the parameters have accordance with biological experimental results, which indicate that our method has a good predictability for culture conditions optimization.

  20. Optimal design issues of a gas-to-liquid process

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee, Ahmad

    2012-07-01

    Interests in Fischer-Tropsch (FT) synthesis is increasing rapidly due to the recent improvements of the technology, clean-burning fuels (low sulphur, low aromatics) derived from the FT process and the realization that the process can be used to monetize stranded natural gas resources. The economy of GTL plants depends very much on the natural gas price and there is a strong incentive to reduce the investment cost and in addition there is a need to improve energy efficiency and carbon efficiency. A model is constructed based on the available information in open literature. This model is used to simulate the GTL process with UNISIM DESIGN process simulator. In the FT reactor with cobalt based catalyst, Co2 is inert and will accumulate in the system. Five placements of Co2 removal unit in the GTL process are evaluated from an economical point of view. For each alternative, the process is optimized with respect to steam to carbon ratio, purge ratio of light ends, amount of tail gas recycled to syngas and FT units, reactor volume, and Co2 recovery. The results show that carbon and energy efficiencies and the annual net cash flow of the process with or without Co2 removal unit are not significantly different and there is not much to gain by removing Co2 from the process. It is optimal to recycle about 97 % of the light ends to the process (mainly to the FT unit) to obtain higher conversion of CO and H2 in the reactor. Different syngas configurations in a gas-to-liquid (GTL) plant are studied including auto-thermal reformer (ATR), combined reformer, and series arrangement of Gas Heated Reformer (GHR) and ATR. The Fischer-Tropsch (FT) reactor is based on cobalt catalyst and the degrees of freedom are; steam to carbon ratio, purge ratio of light ends, amount of tail gas recycled to synthesis gas (syngas) and Fischer-Tropsch (FT) synthesis units, and reactor volume. The production rate of liquid hydrocarbons is maximized for each syngas configuration. Installing a steam

  1. Study on the Optimization of Liquid Fermentation Culture Medium for Producing Phellinus Linteus Expolysaccharide by Response Surface Methodology%响应面法优化桑黄菌产胞外多糖液体发酵培养基的研究

    Institute of Scientific and Technical Information of China (English)

    牛广财; 朱丹; 李志江; 郭希娟; 左锋

    2009-01-01

    Liquid fermentation culture medium for producing phellinus linteus expolysac-charide was optimized by response surface methodology. The effects of carbon source, nitrogen source, metallic ions, vitamin on the yield of mycelium and expolysaccharide were studied. Based on single factor experiments, the concentration of carbon source, nitrogen source, metallic ions and vitamin was analyzed by Box-Benhnken design and response surface methodology. The results showed that the optimal culture medium was as follows: 43.608 g/L brown rice powder, 4.251 g/L soybean powder, 3.251 g/L KH_2PO_4, 325.531 μg/L V_(B2). The average yield of expolysaccharide reached 3.088 g/L after validated fermentation experiment under optimal condition.%利用响应面分析法对对桑黄菌产胞外多糖的液体发酵培养基进行了优化.研究碳源、氮源、无机盐和维生素对桑黄菌丝及胞外多糖产量的影响.在单因素筛选实验的基础上,利用Box-Benhnken设计和响应面分析法对碳源、氮源、无机盐和维生素进行分析.结果表明,桑黄菌产胞外多糖的液体发酵培养基最佳组合为:糙米粉为43.608 g/L,豆饼扮为4.251 g/L,KH_2PO_4为3.251 g/L,V_(B2)为325.531μg/L.在此条件下的验证试验表明,胞外多糖平均可达3.088 g/L.

  2. Apoptosis at inflection point in liquid culture of budding yeasts.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Hagiwara

    Full Text Available Budding yeasts are highly suitable for aging studies, because the number of bud scars (stage proportionally correlates with age. Its maximum stages are known to reach at 20-30 stages on an isolated agar medium. However, their stage dynamics in a liquid culture is virtually unknown. We investigate the population dynamics by counting scars in each cell. Here one cell division produces one new cell and one bud scar. This simple rule leads to a conservation law: "The total number of bud scars is equal to the total number of cells." We find a large discrepancy: extremely fewer cells with over 5 scars than expected. Almost all cells with 6 or more scars disappear within a short period of time in the late log phase (corresponds to the inflection point. This discrepancy is confirmed directly by the microscopic observations of broken cells. This finding implies apoptosis in older cells (6 scars or more.

  3. Optimization and Application of Liquid Chromatography Determination of Dispersive Liquid-liquid Microextraction Purified Astaxanthin in Shrimp Waste

    Institute of Scientific and Technical Information of China (English)

    ZHU Tao; ROW Kyung-ho

    2013-01-01

    A new molecularly imprinted solid-phase extraction(MISPE) monolithic cartridge was synthesized,and MISPE-DLLME(DLLME=dispersive liquid-liquid microextraction) was developed for purification of astaxanthin in shrimp waste.The eluent(methanol) from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography(HPLC) analysis.The mobile phase was methanol-acetonitrile-water-dichloromethane(85:5:5:5,volume ratio),flow rate was 0.7 mL/min and UV wavelength was 476 nm.Under optimal conditions,good linearity was obtained in a range of 0.2-200.0 μg/mL(r2=0.9998) with a limit of detection(LOD) of 0.08 μg/mL,and the extraction recoveries at three spiked levels ranged from 88.3%-92.5% with a relative standard deviation(RSD) less than 4.3%.Moreover,the mean contents of astaxanthin in the three batches of shrimp waste were 95.9,85.4 and 77.2 μg/g,respectively.This method combining the advantages of MISPE and DLLME results in high selectivity and low cost,which was applied to determining the astaxanthin level in shrimp waste samples.

  4. Hybrid Modeling and Optimization of Yogurt Starter Culture Continuous Fermentation

    Directory of Open Access Journals (Sweden)

    Silviya Popova

    2009-10-01

    Full Text Available The present paper presents a hybrid model of yogurt starter mixed culture fermentation. The main nonlinearities within a classical structure of continuous process model are replaced by neural networks. The new hybrid model accounts for the dependence of the two microorganisms' kinetics from the on-line measured characteristics of the culture medium - pH. Then the model was used further for calculation of the optimal time profile of pH. The obtained results are with agreement with the experimental once.

  5. Hyphenation of optimized microfluidic sample preparation with nano liquid chromatography for faster and greener alkaloid analysis

    NARCIS (Netherlands)

    Shen, Y.; Beek, van T.A.; Zuilhof, H.; Chen, B.

    2013-01-01

    A glass liquid–liquid extraction (LLE) microchip with three parallel 3.5 cm long and 100 µm wide interconnecting channels was optimized in terms of more environmentally friendly (greener) solvents and extraction efficiency. In addition, the optimized chip was successfully hyphenated with nano-liquid

  6. Hyphenation of optimized microfluidic sample preparation with nano liquid chromatography for faster and greener alkaloid analysis

    NARCIS (Netherlands)

    Shen, Y.; Beek, van T.A.; Zuilhof, H.; Chen, B.

    2013-01-01

    A glass liquid–liquid extraction (LLE) microchip with three parallel 3.5 cm long and 100 µm wide interconnecting channels was optimized in terms of more environmentally friendly (greener) solvents and extraction efficiency. In addition, the optimized chip was successfully hyphenated with nano-liquid

  7. OPTIMAL PORTFOLIO ON TRACKING THE EXPECTED WEALTH PROCESS WITH LIQUIDITY CONSTRAINTS

    Institute of Scientific and Technical Information of China (English)

    Luo Kui; Wang Guangming; Hu Yijun

    2011-01-01

    In this article, the authors consider the optimal portfolio on tracking the expected wealth process with liquidity constraints. The constrained optimal portfolio is first formulated as minimizing the cumulate variance between the wealth process and the expected wealth process. Then, the dynamic programming methodology is applied to reduce the whole problem to solving the Hamilton-Jacobi-Bellman equation coupled with the liquidity constraint, and the method of Lagrange multiplier is applied to handle the constraint. Finally, a numerical method is proposed to solve the constrained HJB equation and the constrained optimal strategy. Especially, the explicit solution to this optimal problem is derived when there is no liquidity constraint.

  8. Optimization of lycopene extraction from tomato cell suspension culture by response surface methodology.

    Science.gov (United States)

    Lu, Chi-Hua; Engelmann, Nancy J; Lila, Mary Ann; Erdman, John W

    2008-09-10

    Radioisotope-labeled lycopene is an important tool for biomedical research but currently is not commercially available. A tomato cell suspension culture system for the production of radioisotope-labeled lycopene was previously developed in our laboratory. In the current study, the goal was to optimize the lycopene extraction efficiency from tomato cell cultures for preparatory high-performance liquid chromatography (HPLC) separation. We employed response surface methodology (RSM), which combines fractional factorial design and a second-degree polynomial model. Tomato cells were homogenized with ethanol, saponified by KOH, and extracted with hexane, and the lycopene content was analyzed by HPLC-PDA. We varied five factors at five levels: ethanol volume (1.33-4 mL/g); homogenization period (0-40 s/g); saturated KOH solution volume (0-0.67 mL/g); hexane volume (1.67-3 mL/g); and vortex period (5-25 s/g). Ridge analysis by SAS suggested that the optimal extraction procedure to extract 1 g of tomato cells was at 1.56 mL of ethanol, 28 s homogenization, 0.29 mL of KOH, 2.49 mL of hexane, and 17.5 s vortex. These optimal conditions predicted by RSM were confirmed to enhance lycopene yield from standardized tomato cell cultures by more than 3-fold.

  9. Optimization based on retention prediction and information theory for liquid-chromatographic analysis of alkylbenzenes

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Rieko; Hayashi Yuzuru; Suzuki Takashi; Saito Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan)); Jinno Kiyokatsu (Toyohashi Univ. of Technology (Japan))

    1991-11-01

    The mobile phase composition and column length are optimized for analyses of six alkylbenzenes in reversed-phase liquid chromatography with the aid of retention prediction and information theory. Optimal conditions selected according to the resolution Rs and information theory are evaluated from the viewpoint of the precision and analytical efficiency (rapidity) of chromatography. The combination of the information-theoretical optimization with the retention prediction will accelerate the development in the automation of liquid-chromatographic analysis.

  10. Optimizing culture medium for meristem tissue culture of several Saccharum species and commercial hybrids

    Science.gov (United States)

    The optimal range of medium nutrients and plant growth regulators (PGR) was investigated for in vitro culture of diverse sugarcane species and cultivars. Macro-nutrients, nitrogen (N), phosphorous (P) and potassium (K), were essential for growth of leaf primordia. Although the best concentration of ...

  11. Improvement of Aconitum napellus micropropagation by liquid culture on floating membrane rafts.

    Science.gov (United States)

    Watad, A A; Kochba, M; Nissim, A; Gaba, V

    1995-03-01

    An efficient method was developed using floating membrane rafts (Liferaft(™)) for the micropropagation of Aconitum napellus (Ranunculaceae), a cut flower crop with a low natural propagation rate. This was achieved by introducing shoot tips into culture on Murashige and Skoog's (1962) solid medium, or liquid medium-supported rafts, supplemented by different levels of benzyl adenine (BA). Optimum shoot proliferation on solid medium required 4mg/l BA, whereas for expiants supported on rafts optimal proliferation was achieved at 0.25mg/l BA. Maximum shoot proliferation was found using the floating rafts (propagation ratio of 4.2 per month), 45% higher than the maximum value on solid medium. A similar value could be obtained on solid medium after a period of 2 months. The optimal response to BA was similar for fresh weight gain and shoot length. Growth in a shallow layer of liquid in shake flasks gives a similar shoot multiplication rate to that on floating rafts; however, submerged leaves brown and die.

  12. Optimization of the liquid biofertilizer production in batch fermentation with by-product from MSG

    Science.gov (United States)

    Namfon, Panjanapongchai; Ratchanok, Sahaworarak; Chalida, Daengbussade

    2017-03-01

    The long term use of chemical fertilizers destroyed the friability of soil which obviously decreased quantity and quality of crops and especially affect microorganisms living in soils. The bio-fertilizer with microbial consortium is an environmental friendly alternative to solve this bottleneck due to harboring soil microorganisms such as Bacillus sp., Micrococcus sp., Pseudomonas sp., Staphylococcus sp. and Deinococcus sp. produced with natural by-product or waste from industries that is alternative and sustainable such as nutrient-rich (by-product) from Mono Sodium Glutamate (MSG) for producing liquid biofertilizer by batch fermentation. In this work, the concentration of reducing sugar from substrate as main carbon source was evaluated in shake flask with mixed cultures. The optimal conditions were studied comparing with two levels of reducing sugar concentration (10, 20 g/L) and inoculums concentration (10, 20 %v/v) with using (2×2) full factorial design. The results indicated that the by-product from monosodium glutamate is feasible for fermentation and inoculums concentration is mainly influenced the batch fermentation process. Moreover, the combined 20 g/L and 10%v/v were considerably concluded as an optimal condition, of which the concentration of vegetative cells and spores attained at 8.29×109 CFU/mL and 1.97×105 CFU/mL, respectively. Their spores cell yields from reducing sugar (Yx/s) were obtained at 1.22×106 and 3.34×105 CFU/g were markedly different. In conclusion, the liquid Biofertilizer was produced satisfactorily at 20 g/L reducing sugar and 10% v/v inoculums in shake flask culture. Moreover, these results suggested that the by-product from monosodium glutamate is feasible for low-cost substrate in economical scale and environmental-friendly.

  13. Synthesis of bacteriocins in liquid cultures of Streptococcus mutans.

    Science.gov (United States)

    Kelstrup, J; Funder-Nielsen, T D

    1977-06-01

    Strains of Streptococcus mutans synthesized bacteriocins in agar plates, but synthesis of detectable bacteriocins in liquid media took place only under certain culture conditions. The composition of the medium proved to be crucial. Trypticase Soy Broth with 4% Yeast Extract meeting the requirements. The effect of the Yeast Extract is obscure, for some strains also formed detectable bacteriocins in a special Trypticase medium without this agent. It was noted that the broth should be filter-sterilized rather than autoclaved and only a few days old. Attempts at liberating cell-bound bacteriocins from washed cells were unsuccessful, even when they were treated with ultrasound, EDTA, or various chemicals followed by ultrasound. On the basis of size and sensitivity to heat the bacteriocins could be divided into two groups, while their resistance to ether and chloroform and to trypsin did not follow this pattern. Dependence on plasmids could not be demonstrated by attempts at curing with acridine orange or ethidium bromide; and the involvement of phages was unlikely, since the inhibition was not transmissible and phage-like structures were not observed in the electron microscope.

  14. Optimization of a scroll compressor for liquid flooding

    OpenAIRE

    Bell, Ian; Groll, Eckhard; Braun, James; King, Galen; W. Travis, Horton

    2012-01-01

    In two companion papers, simulation models for the working processes of liquid-flooded scroll compressors and expanders have been developed and validated against experimental data. In this study, analytic models are presented for the modes of irreversibility generation in the liquid-flooded scroll compressor including built-in volume ratio maladjustment, pressure drop and leakage. A thermodynamic model is used to derive the ideal volume ratio for a liquid-flooded compressor, which is higher t...

  15. Blanket-relevant liquid metal MHD channel flows: Data base and optimization simulation development

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, I.A.; Kirillov, I.R.; Sidorenkov, S.I. [D.V. Efremov Inst. of Electrophysical Apparatus, St Petersburg (Russian Federation)

    1995-12-31

    The problems of generalization and integration of test, theoretical and design data relevant to liquid metal (LM) blanket are discussed in present work. First results on MHD data base and LM blanket optimization codes are presented.

  16. Optimizing in vitro culture conditions leads to a significantly shorter production time of human dermo-epidermal skin substitutes.

    Science.gov (United States)

    Pontiggia, Luca; Klar, Agnieszka; Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Meuli, Martin; Reichmann, Ernst

    2013-03-01

    Autologous dermo-epidermal skin substitutes (DESS) generated in vitro represent a promising therapeutic means to treat full-thickness skin defects in clinical practice. A serious drawback with regard to acute patients is the relatively long production time of 3-4 weeks. With this experimental study we aimed to decrease the production time of DESS without compromising their quality. Two in vitro steps of DESS construction were varied: the pre-cultivation time of fibroblasts in hydrogels (1, 3, and 6 days), and the culture time of keratinocytes (3, 6, and 12 days) before transplantation of DESS on nude rats. Additionally, the impact of the air-liquid interface culture during 3 days before transplantation was investigated. 3 weeks after transplantation, the macroscopic appearance was evaluated and histological sections were produced to analyze structure and thickness of epidermis and dermis, the stratification of the epidermis, and the presence of a basal lamina. Optimal DESS formation was obtained with a fibroblast pre-cultivation time of 6 days. The minimal culture time of keratinocytes on hydrogels was also 6 days. The air-liquid interface culture did not improve graft quality. By optimizing our in vitro culture conditions, it was possible to very substantially reduce the production time for DESS from 21 to 12 days. However, pre-cultivation of fibroblasts in the dermal equivalent and proliferation of keratinocytes before transplantation remain crucial for an equilibrated maturation of the epidermis and cannot be completely skipped.

  17. Optimizing culture conditions for establishment of hairy root culture of Semecarpus anacardium L.

    Science.gov (United States)

    Panda, Bhuban Mohan; Mehta, Urmil J; Hazra, Sulekha

    2017-05-01

    Semecarpus anacardium L. is a tree species which produces secondary metabolites of medicinal importance. Roots of the plant have been traditionally used in folk medicines. Different strains of Agrobacterium rhizogenes (A4, ATCC15834 and LBA 9402) were used for induction of hairy roots in in vitro grown tissues of the plant. Hairy root initiation was observed after 25-30 days of infection. Optimum transformation frequency of 61% was achieved on leaf explants with ATCC15834 strain. Infection time of 30 min resulted in greater transformation frequency compared to 10 and 20 min, respectively. The hairy roots cultured in growth regulator-free semi-solid woody plant medium differentiated into callus. Whole shoots infected with ATCC 15834 were found to produce more transformants upon co-cultivation for 4 (65%) and 5 (67%) days. Induction of hairy roots in stem explants infected with ATCC 15834 was lower (52%) compared to leaves (62%) after 4 days of co-cultivation. In A4 and LBA9402 strains transformation efficiency was 49 ± 2.8% and 36 ± 5.7% in shoots after 4 days of co-cultivation. Transformation frequency was higher in ATCC15834 strain, irrespective of explants. The hairy roots of S. anacardium elongated slowly upon transfer to half-strength liquid medium. After 3-4 passages in liquid medium slender hairy roots started differentiating which were separated from the original explants. Visible growth of the roots was observed in hormone-free liquid medium after 2-3 months of culturing. Polymerase chain reaction with gene-specific primers from rol A, B and C genes confirms the positive transformation events.

  18. Regulation for Optimal Liquid Products during Biomass Pyrolysis: A Review

    Science.gov (United States)

    Wang, F.; Hu, L. J.; Zheng, Y. W.; Huang, Y. B.; Yang, X. Q.; Liu, C.; Kang, J.; Zheng, Z. F.

    2016-08-01

    The liquid product obtained from biomass pyrolysis is very valuable that it could be used for extraction of chemicals as well as for liquid fuel. The desire goal is to obtain the most bio-oil with desired higher heating value (HHV), high physicochemical stability. The yields and chemical composition of products from biomass pyrolysis are closely related to the feedstock, pyrolysis parameters and catalysts. Current researches mainly concentrated on the co-pyrolysis of different biomass and introduce of novel catalysts as well as the combined effect of catalysts and pyrolysis parameters. This review starts with the chemical composition of biomass and the fundamental parameters and focuses on the influence of catalysts on bio-oil. What is more, the pyrolysis facilities at commercial scales were also involved. The classic researches and the current literature about the yield and composition of products (mainly liquid products) are summarized.

  19. Optimization design of a Lamb wave device for density sensing of nonviscous liquid.

    Science.gov (United States)

    Chen, Zhijun; Li, Lianger; Shi, Wenkang; Guo, Huawei

    2007-10-01

    A Lamb wave device composed of a piezoelectric plate loaded with a nonviscous liquid layer is presented. The relation between the Lamb wave phase velocity and the liquid density can be used for liquid density sensing. In this paper, utilizing the partial wave theory, the concept of effective permittivity is introduced to analyze the Lamb wave's excitation and the phase velocity calculation under a certain liquid density. The interface between the Lamb wave device and the liquid layer is metallized to eliminate the influence of liquid electrical properties when sensing liquid density. Based on the theory model, the phase difference measurement method is adopted to study the device's sensitivity to liquid density. In order to achieve high sensitivity to liquid density with sufficient excitation efficiency of Lamb wave, the optimal parameters of the Lamb wave device including plate thickness and cut orientation are obtained by numerical calculation. The experimental results are found to be in agreement with the theoretical simulations, verifying the validity of the theory model and the practicability of the optimization design.

  20. Survival of Suspension-cultured Sycamore Cells Cooled to the Temperature of Liquid Nitrogen.

    Science.gov (United States)

    Sugawara, Y; Sakai, A

    1974-11-01

    Suspension-cultured cells of sycamore (Acer pseudoplatanus L.) which were immersed in liquid nitrogen after prefreezing to the temperatures from -30 to -50 C in the presence of dimethylsulfoxide and glucose as cryoprotective additive could proliferate vigorously when rewarmed rapidly in water at 40 C. For maintaining high viability of the cells after immersion in liquid nitrogen, it seems to be essential to use the cells at the later lag phase or the early cell division phase. This study provides a possibility for long term preservation in liquid nitrogen of plant-cultured lines.

  1. An Air-Liquid Interface Culture System for 3D Organoid Culture of Diverse Primary Gastrointestinal Tissues.

    Science.gov (United States)

    Li, Xingnan; Ootani, Akifumi; Kuo, Calvin

    2016-01-01

    Conventional in vitro analysis of gastrointestinal epithelium usually relies on two-dimensional (2D) culture of epithelial cell lines as monolayer on impermeable surfaces. However, the lack of context of differentiation and tissue architecture in 2D culture can hinder the faithful recapitulation of the phenotypic and morphological characteristics of native epithelium. Here, we describe a robust long-term three-dimensional (3D) culture methodology for gastrointestinal culture, which incorporates both epithelial and mesenchymal/stromal components into a collagen-based air-liquid interface 3D culture system. This system allows vigorously expansion of primary gastrointestinal epithelium for over 60 days as organoids with both proliferation and multilineage differentiation, indicating successful long-term intestinal culture within a microenvironment accurately recapitulating the stem cell niche.

  2. Development of an optimized medium, strain and high-throughput culturing methods for Methylobacterium extorquens

    National Research Council Canada - National Science Library

    Delaney, Nigel F; Kaczmarek, Maria E; Ward, Lewis M; Swanson, Paige K; Lee, Ming-Chun; Marx, Christopher J

    2013-01-01

    .... Here we develop a new system for high-throughput batch culture of M. extorquens in microtiter plates by jointly optimizing the properties of the organism, the growth media and the culturing system...

  3. Optimization of Zoom Lens with Discrete State of Liquid Lens Elements by Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Cheng-Mu Tsai

    2015-01-01

    Full Text Available This paper is to employ liquid lens elements to design a lens with zoom function by using the genetic algorithm (GA optimization. The liquid lens elements used in the proposal can apply voltage adjustment to generate the electrical field that induces the liquid with electric conductivity to vary the surface curvature between two different kinds of liquids. According to the voltage level, the liquid lens element makes the discrete variation of the curvature and thickness realize the zoom function without moving the lens groups so that the overall length can be reduced. However, it is difficult to design the zoom lens under the discrete variation of the curvature and thickness in the liquid lens elements and the mechanical space that is constantly limited. The GA offers a flexible way for lens optimization. We regarded the spot size as the fitness function to look for the optimum curvatures, thickness, and the corresponding statuses of liquid lens elements for the zoom lens. As a result, the zoom lens with constant space can be realized by running the selection, crossover, and mutation operation in the GA optimization.

  4. Optimization of Storage Temperature for Cultured ARPE-19 Cells

    Directory of Open Access Journals (Sweden)

    Lara Pasovic

    2013-01-01

    Full Text Available Purpose. The establishment of future retinal pigment epithelium (RPE replacement therapy is partly dependent on the availability of tissue-engineered RPE cells, which may be enhanced by the development of suitable storage methods for RPE. This study investigates the effect of different storage temperatures on the viability, morphology, and phenotype of cultured RPE. Methods. ARPE-19 cells were cultured under standard conditions and stored in HEPES-buffered MEM at nine temperatures (4°C, 8°C, 12°C, 16°C, 20°C, 24°C, 28°C, 32°C, and 37°C for seven days. Viability and phenotype were assessed by a microplate fluorometer and epifluorescence microscopy, while morphology was analyzed by scanning electron microscopy. Results. The percentage of viable cells preserved after storage was highest in the 16°C group (48.7%±9.8%; P<0.01 compared to 4°C, 8°C, and 24°C–37°C; P<0.05 compared to 12°C. Ultrastructure was best preserved at 12°C, 16°C, and 20°C. Expression of actin, ZO-1, PCNA, caspase-3, and RPE65 was maintained after storage at 16°C compared to control cells that were not stored. Conclusion. Out of nine temperatures tested between 4°C and 37°C, storage at 12°C, 16°C, and 20°C was optimal for maintenance of RPE cell viability, morphology, and phenotype. The preservation of RPE cells is critically dependent on storage temperature.

  5. Optimal synthesis and characterization of Ag nanofluids by electrical explosion of wires in liquids

    Directory of Open Access Journals (Sweden)

    Won Lee Seung

    2011-01-01

    Full Text Available Abstract Silver nanoparticles were produced by electrical explosion of wires in liquids with no additive. In this study, we optimized the fabrication method and examined the effects of manufacturing process parameters. Morphology and size of the Ag nanoparticles were determined using transmission electron microscopy and field-emission scanning electron microscopy. Size and zeta potential were analyzed using dynamic light scattering. A response optimization technique showed that optimal conditions were achieved when capacitance was 30 μF, wire length was 38 mm, liquid volume was 500 mL, and the liquid type was deionized water. The average Ag nanoparticle size in water was 118.9 nm and the zeta potential was -42.5 mV. The critical heat flux of the 0.001-vol.% Ag nanofluid was higher than pure water.

  6. Human Performance Optimization: Culture Change and Paradigm Shift.

    Science.gov (United States)

    Deuster, Patricia A; OʼConnor, Francis G

    2015-11-01

    The term "Human Performance Optimization" (HPO) emerged across the Department of Defense (DoD) around 2006 when the importance of human performance for military success on the battlefield was acknowledged. Likewise, the term Total Force Fitness (TFF) arose as a conceptual framework within DoD in response to the need for a more holistic approach to the unparalleled operational demands with multiple deployments and strains on the United States Armed Forces. Both HPO and TFF are frameworks for enhancing and sustaining the health, well-being, and performance among our warriors and their families; they are fundamental to accomplishing our nation's mission. A demands-resources model for HPO is presented within the context of TFF to assist in operationalizing actions to enhance performance. In addition, the role leaders can serve is discussed; leaders are uniquely postured in the military chain of command to directly influence a culture of fitness for a ready force, and promote the concept that service members are ultimately responsible for their fitness and performance.

  7. Design optimization of seal structure for sealing liquid by magnetic fluids

    Science.gov (United States)

    Liu, Tonggang; Cheng, Yusheng; Yang, Zhiyi

    2005-03-01

    The durability of the magnetic fluid seal clearly decreases when sealing another liquid because of the interface instability caused by the applied magnetic field and the velocity difference of the two liquids. With an intention to establish a stable interface during sealing liquid, a new magnetic fluid seal was developed in this paper. The parameters of the structure were optimized by a simulation apparatus. And the magnetic fluid seal designed based on the optimum parameters shows good performance and long life for sealing lubricating oil.

  8. Coculture of osteoblasts and endothelial cells: optimization of culture medium and cell ratio

    NARCIS (Netherlands)

    Ma, J.; Beucken, J.J. van den; Yang, F.; Both, S.K.; Cui, F.Z.; Pan, J.; Jansen, J.A.

    2011-01-01

    Vascularization strategies in cell-based bone tissue engineering depend on optimal culture conditions. The present study aimed to determine optimal cell culture medium and cell ratio for cocultures of human marrow stromal cells (HMSCs) and human umbilical vein endothelial cells (HUVECs) in view of

  9. Accumulation of dibenzocyclooctadiene lignans in agar cultures and in stationary and agitated liquid cultures of Schisandra chinensis (Turcz.) Baill.

    Science.gov (United States)

    Szopa, Agnieszka; Kokotkiewicz, Adam; Marzec-Wróblewska, Urszula; Bucinski, Adam; Luczkiewicz, Maria; Ekiert, Halina

    2016-05-01

    Schisandra chinensis plant in vitro cultures were maintained on Murashige and Skoog (MS) medium supplemented with 3 mg/l 6-benzyladenine (BA) and 1 mg/l 1-naphthaleneacetic acid (NAA) in an agar system and also in two different liquid systems: stationary and agitated. Liquid cultures were grown in batch (30 and 60 days) and fed-batch modes. In the methanolic extracts from lyophilized biomasses and in the media, quantification of fourteen dibenzocyclooctadiene lignans identified based on co-chromatography with authentic standards using high-performance liquid chromatography with diode array detection (HPLC-DAD) and/or liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI-MS) methods. For comparison purposes, phytochemical analyses were performed of lignans in the leaves and fruits of the parent plant. The main lignans detected in the biomass extracts from all the tested systems were schisandrin (max. 65.62 mg/100 g dry weight (DW)), angeloyl-/tigloylgomisin Q (max. 49.73 mg/100 g DW), deoxyschisandrin (max. 43.65 mg/100 g DW), and gomisin A (max. 34.36 mg/100 g DW). The highest total amounts of lignans in the two tested stationary systems were found in extracts from the biomass harvested after 30 days of batch cultivation: 237.86 mg/100 g DW and 274.65 mg/100 g DW, respectively. In the agitated culture, the total content reached a maximum value of 244.80 mg/100 g DW after 60 days of the fed-batch mode of cultivation. The lignans were not detected in the media. This is the first report which documents the potential usefulness of S. chinensis shoot cultures cultivated in liquid systems for practical purposes.

  10. Formation and changes of the subembryonic liquid from turned, unturned, and cultured Japanese quail eggs.

    Science.gov (United States)

    Wittmann, J; Kaltner, H

    1988-08-01

    Japanese quail eggs belonging to the same flock of hens were incubated under different conditions: group 1 eggs were turned 3 times a day, group 2 eggs were left unturned, and group 3 eggs were cultured and left unturned. The results indicate that failure to turn eggs results in a delayed efflux of liquid and glucose from albumen and from the subembryonic liquid. Furthermore, the major difference between unturned and cultured eggs was that in the first group the glucose levels and in the second group the lactate levels of the subembryonic liquid were increased. It is suggested that reduced glucose supply may be involved in the disturbance of development of unturned and cultured eggs.

  11. Flow Rates in Liquid Chromatography, Gas Chromatography and Supercritical Fluid Chromatography: A Tool for Optimization

    OpenAIRE

    Joris Meurs

    2016-01-01

    This paper aimed to develop a standalone application for optimizing flow rates in liquid chromatography (LC), gas chromatography (GC) and supercritical fluid chromatography (SFC). To do so, Van Deemter’s equation, Knox’ equation and Golay’s equation were implemented in a MATLAB script and subsequently a graphical user interface (GUI) was created. The application will show the optimal flow rate or linear velocity and the corresponding plate height for the set input parameters. Furthermore, a p...

  12. A simple method for the quantitative analysis of tyrosol by hplc in liquid Czapek Cultures from endophytic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Denise O.; Pupo, Monica T. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Ciencias Farmaceuticas]. E-mail: mtpupo@fcfrp.usp.br; Borges, Keyller B.; Bonato, Pierina S. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Fisica e Quimica

    2009-07-01

    Tyrosol is a possible quorum sensing molecule in endophytic fungi. High-performance liquid chromatography (HPLC) coupled with diode array detector (DAD) was used for the analysis of tyrosol in liquid Czapek fungal cultures. The optimized conditions were gradient mobile phase, in linear mode, consisting initially of acetonitrile/water (1:9 v/v) and increasing up to acetonitrile (100%) in 30 minutes at a flow rate of 1 mL min{sup -1}. The column used was a Zorbax ODS (250 x 4.6 mm, 5 {mu}m) at 25 deg C. Liquid-liquid extraction of 0.5 mL medium (pH 7.0) with ethyl acetate and injection of 20 {mu}L after solvent evaporation under air flow gave good results. Some validation parameters obtained were: linearity 0.0125-5.0 {mu}g mL{sup -1} medium (r = 0.9967), quantification limit of 0.0125 {mu}g mL{sup -1} medium, %CV (precision) and %E (accuracy) bellow 15% and recovery around 80%. Therefore, the developed method presented satisfactory validation parameters and it was efficient for the analysis of tyrosol in Czapek medium. (author)

  13. Optimal Design of Liquid Dampers for Structural Vibration Control Based on GA and H∞ Norm

    Directory of Open Access Journals (Sweden)

    Linsheng Huo

    2013-01-01

    Full Text Available This paper focused on the optimal design of liquid dampers for the seismic response control of structures. The H∞ norm of the transfer function from the ground motion to the structural response is selected as the optimal objective. The optimization procedure is carried out by using Genetic Algorithms (GAs in order to reach an optimal solution. The proposed method has the advantages that it is unnecessary to solve the equation of motion for the control system and that the obtained optimal parameters of dampers are not dependent on the ground motion records. The influences of weighted functions on the optimization results are analyzed. The generality and effeteness of the proposed method are verified by the time history analysis of a 3-story structure subjected to earthquake records in different sites. The results show that the structural responses can be effectively reduced subjected to earthquake excitation at different sites.

  14. Designing & Optimizing a Moving Magnet Pump for Liquid Sodium Systems

    Science.gov (United States)

    Hvasta, Michael G.

    Advanced materials such as NF-616, NF-709, HT-UPS, and silicon carbide (SiC) have greater strength than traditional structural materials such as 316-SS. Thus, using these high-strength materials to build sodium-cooled fast reactors (SFRs) could potentially reduce construction costs by lessening the required amount of material, and increase the efficiency of electromagnetic pumps by limiting ohmic heating within the pump duct walls. However, information pertaining to the sodium-compatibility of these alloys and ceramics is very sparse. Therefore, two separate test facilities were built to study the impact of both static and dynamic sodium corrosion The dynamic test facility enabled sodium corrosion to be studied under prototypic SFR operating conditions (T = 500 [C], V = 9.35 [m/s], CO = 2-3 [wppm]). The oxygen concentration, CO, within the dynamic test facility was maintained using a cold trap and measured with a plugging meter. The flow rate of the sodium was measured using a calibrated electromagnetic flowmeter. A moving magnet pump (MMP) was used to move the liquid sodium past the corrosion samples at a high velocity. Using newly developed theory, it was found that MMP performance could be accurately modeled and predicted for a wide variety of pump configurations.

  15. Optimization of screening for radioactivity in urine by liquid scintillation.

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Sonoya Toyoko; Reese, Robert P.; Preston, Rose T. (Technadyne Engineering Consultants, Inc., Albuquerque, NM)

    2007-08-01

    Numerous events have or could have resulted in the inadvertent uptake of radionuclides by fairly large populations. Should a population receive an uptake, valuable information could be obtained by using liquid scintillation counting (LSC) techniques to quickly screen urine from a sample of the affected population. This study investigates such LSC parameters as discrimination, quench, volume, and count time to yield guidelines for analyzing urine in an emergency situation. Through analyzing variations of the volume and their relationships to the minimum detectable activity (MDA), the optimum ratio of sample size to scintillating chemical cocktail was found to be 1:3. Using this optimum volume size, the alpha MDA varied from 2100 pCi/L for a 30-second count time to 35 pCi/L for a 1000-minute count time. The typical count time used by the Sandia National Laboratories Radiation Protection Sample Diagnostics program is 30 minutes, which yields an alpha MDA of 200 pCi/L. Because MDA is inversely proportional to the square root of the count time, count time can be reduced in an emergency situation to achieve the desired MDA or response time. Note that approximately 25% of the response time is used to prepare the samples and complete the associated paperwork. It was also found that if the nuclide of interest is an unknown, pregenerated discriminator settings and efficiency calibrations can be used to produce an activity value within a factor of two, which is acceptable for a screening method.

  16. Optimal site for throat culture: tonsillar surface versus posterior pharyngeal wall

    NARCIS (Netherlands)

    E.L. van der Veen; E.A.M. Sanders; W.J.M. Videler; B.K. van Staaij; P.P.G. van Benthem; A.G.M. Schilder

    2006-01-01

    To determine the optimal site of throat culture for the detection of potential pathogens by comparing culture results from the tonsillar surface and the posterior pharyngeal wall in children selected for adenotonsillectomy and in children without upper respiratory disease. Cotton culture swabs were

  17. Stationary phase optimized selectivity liquid chromatography: Basic possibilities of serially connected columns using the "PRISMA" principle.

    Science.gov (United States)

    Nyiredy, Sz; Szucs, Zoltán; Szepesy, L

    2007-07-20

    A new procedure (stationary phase optimized selectivity liquid chromatography: SOS-LC) is described for the optimization of the HPLC stationary phase, using serially connected columns and the principle of the "PRISMA" model. The retention factors (k) of the analytes were determined on three different stationary phases. By use of these data the k values were predicted applying theoretically combined stationary phases. These predictions resulted in numerous intermediate theoretical separations from among which only the optimal one was assembled and tested. The overall selectivity of this separation was better than that of any individual base stationary phase. SOS-LC is independent of the mechanism and the scale of separation.

  18. Dense cultures of Neisseria gonorrhoeae in liquid medium.

    Science.gov (United States)

    Brookes, R; Hedén, C G

    1967-03-01

    Cultivation of Neisseria gonorrhoeae was effected in a conical glass culture vessel surrounded by a constant-temperature water jacket, and with facilities for stirring, aeration, and pH measurement and control. With the use of an aerated peptone-based medium, containing polypropylene glycol to prevent foam build-up, the yields obtained over the pH range from 5.8 to 7.4 were determined. The greatest yield was obtained at pH 6.4 when the dry weight was 1.5 g/liter. At pH 7.2 to 7.6, lysis was extensive.

  19. Technique for the optimization of the powerhead configuration and performance of liquid rocket engines

    Science.gov (United States)

    St. Germain, Brad David

    The development and optimization of liquid rocket engines is an integral part of space vehicle design, since most Earth-to-orbit launch vehicles to date have used liquid rockets as their main propulsion system. Rocket engine design tools range in fidelity from very simple conceptual level tools to full computational fluid dynamics (CFD) simulations. The level of fidelity of interest in this research is a design tool that determines engine thrust and specific impulse as well as models the powerhead of the engine. This is the highest level of fidelity applicable to a conceptual level design environment where faster running analyses are desired. The optimization of liquid rocket engines using a powerhead analysis tool is a difficult problem, because it involves both continuous and discrete inputs as well as a nonlinear design space. Example continuous inputs are the main combustion chamber pressure, nozzle area ratio, engine mixture ratio, and desired thrust. Example discrete variable inputs are the engine cycle (staged-combustion, gas generator, etc.), fuel/oxidizer combination, and engine material choices. Nonlinear optimization problems involving both continuous and discrete inputs are referred to as Mixed-Integer Nonlinear Programming (MINLP) problems. Many methods exist in literature for solving MINLP problems; however none are applicable for this research. All of the existing MINLP methods require the relaxation of the discrete variables as part of their analysis procedure. This means that the discrete choices must be evaluated at non-discrete values. This is not possible with an engine powerhead design code. Therefore, a new optimization method was developed that uses modified response surface equations to provide lower bounds of the continuous design space for each unique discrete variable combination. These lower bounds are then used to efficiently solve the optimization problem. The new optimization procedure was used to find optimal rocket engine designs

  20. Microbial transformation and sorption of anthracene in liquid culture.

    Science.gov (United States)

    Hadibarata, Tony; Zubir, Meor Mohd Fikri Ahmad; Rubiyatno; Chuang, Teh Zee

    2013-09-01

    Armillaria sp. F022, a white-rot fungus isolated from decayed wood in tropical rain forest was used to biodegrade anthracene in cultured medium. The percentage of anthracene removal by Armillaria sp. F022 reached 13 % after 7 days and at the end of the experiment, anthracene removal level was at 87 %. The anthracene removal through sorption and transformation was investigated. 69 % of eliminated anthracene was transformed by Armillaria sp. F022 to form other organic structure, while only 18 % was absorbed in the mycelia. In the kinetic experiment, anthracene dissipation will not stop even though the biomass had stopped growing. Anthracene removal by Armillaria sp. F022 was correlated with protein concentration (whole biomass) in the culture. The production of enzyme was affected by biomass production. Anthracene was transformed to two stable metabolic products. The metabolites were extracted in ethyl-acetate, isolated by column chromatography, and then identified using gas chromatography-mass spectrometry (GC-MS).

  1. Biotransformation of tryptophan by liquid medium culture of Psilocybe coprophila (Basidiomycetes).

    Science.gov (United States)

    Alarcón, Julio; Foncea, Leyla; Aguila, Sergio; Alderete, Joel B

    2006-01-01

    Chemical reactions performed by fungi have been used as a modern tool in chemistry. In this work, we show the tryptophan biotransformation with Psilocybe coprophila on liquid culture medium. The results prove once more the versatility of fungi in performing a wide range of industrially attractive chemical reactions.

  2. [Culture medium optimization and primary kinetics analysis for nisin production].

    Science.gov (United States)

    Li, C; Bai, J H; Cai, Z L; Ouyang, F

    2001-03-01

    Response surface methodology was used to optimize a medium for nisin production of Lactococcus lactis. In the first optimization step the influence of sucrose, soybean peptone, yeast extract, potassium dihydrogen phosphate, sodium chloride, and magnesium sulfur on nisin production was evaluated using a fractional factorial design. Potassium dihydrogen phosphate influenced nisin production positively while soybean peptone affected nisin production negatively. The other components had no significant effect on nisin production. The path of steepest ascent was used to approach the optimal region of the medium composition. In the third step the optimal concentrations of KH2PO4 and soybean peptone were determined by a central composite design and response surface analysis. The optimized medium allowed nisin production to be increased from 1074 IU/mL to 2150 IU/mL. The kinetic analysis showed that nisin production fashion at optimized and non-optimized media was not changed and maintained partially growth-associated. But the specific growth rates and the specific nisin production rates for the strain at the optimized medium were bigger than the ones at the non-optimized medium after the cells entered the middle of exponential phase.

  3. Transcriptomic analysis of liquid non-sporulating Streptomyces coelicolor cultures demonstrates the existence of a complex differentiation comparable to that occurring in solid sporulating cultures.

    Science.gov (United States)

    Yagüe, Paula; Rodríguez-García, Antonio; López-García, María Teresa; Rioseras, Beatriz; Martín, Juan Francisco; Sánchez, Jesús; Manteca, Angel

    2014-01-01

    Streptomyces species produce many clinically relevant secondary metabolites and exhibit a complex development that includes hyphal differentiation and sporulation in solid cultures. Industrial fermentations are usually performed in liquid cultures, conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that no differentiation took place. The aim of this work was to compare the transcriptomes of S. coelicolor growing in liquid and solid cultures, deepening the knowledge of Streptomyces differentiation. Microarrays demonstrated that gene expression in liquid and solid cultures were comparable and data indicated that physiological differentiation was similar for both conditions. Eighty-six percent of all transcripts showed similar abundances in liquid and solid cultures, such as those involved in the biosynthesis of actinorhodin (actVA, actII-4) and undecylprodigiosin (redF); activation of secondary metabolism (absR1, ndsA); genes regulating hydrophobic cover formation (aerial mycelium) (bldB, bldC, bldM, bldN, sapA, chpC, chpD, chpE, chpH, ramA, ramC, ramS); and even some genes regulating early stages of sporulation (wblA, whiG, whiH, whiJ). The two most important differences between transcriptomes from liquid and solid cultures were: first, genes related to secondary metabolite biosynthesis (CDA, CPK, coelichelin, desferrioxamine clusters) were highly up-regulated in liquid but not in solid cultures; and second, genes involved in the final stages of hydrophobic cover/spore maturation (chpF, rdlA, whiE, sfr) were up-regulated in solid but not in liquid cultures. New information was also provided for several non-characterized genes differentially expressed in liquid and solid cultures which might be regulating, at least in part, the metabolic and developmental differences observed between liquid and solid cultures.

  4. Transcriptomic analysis of liquid non-sporulating Streptomyces coelicolor cultures demonstrates the existence of a complex differentiation comparable to that occurring in solid sporulating cultures.

    Directory of Open Access Journals (Sweden)

    Paula Yagüe

    Full Text Available Streptomyces species produce many clinically relevant secondary metabolites and exhibit a complex development that includes hyphal differentiation and sporulation in solid cultures. Industrial fermentations are usually performed in liquid cultures, conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that no differentiation took place. The aim of this work was to compare the transcriptomes of S. coelicolor growing in liquid and solid cultures, deepening the knowledge of Streptomyces differentiation. Microarrays demonstrated that gene expression in liquid and solid cultures were comparable and data indicated that physiological differentiation was similar for both conditions. Eighty-six percent of all transcripts showed similar abundances in liquid and solid cultures, such as those involved in the biosynthesis of actinorhodin (actVA, actII-4 and undecylprodigiosin (redF; activation of secondary metabolism (absR1, ndsA; genes regulating hydrophobic cover formation (aerial mycelium (bldB, bldC, bldM, bldN, sapA, chpC, chpD, chpE, chpH, ramA, ramC, ramS; and even some genes regulating early stages of sporulation (wblA, whiG, whiH, whiJ. The two most important differences between transcriptomes from liquid and solid cultures were: first, genes related to secondary metabolite biosynthesis (CDA, CPK, coelichelin, desferrioxamine clusters were highly up-regulated in liquid but not in solid cultures; and second, genes involved in the final stages of hydrophobic cover/spore maturation (chpF, rdlA, whiE, sfr were up-regulated in solid but not in liquid cultures. New information was also provided for several non-characterized genes differentially expressed in liquid and solid cultures which might be regulating, at least in part, the metabolic and developmental differences observed between liquid and solid cultures.

  5. An Optimized Culture Method of Rat Dorsal Root Ganglion Neurons

    Institute of Scientific and Technical Information of China (English)

    LIUYin; CHENJing-Hong; GONGZe-Hui

    2004-01-01

    AIM: To establish a primary culture technique of acutely isolated dorsal root ganglion (DRG) neurons, and provide a simple & useful in vitro model for study of analgesia. Methods: Acutely isolated dorsal root ganglion (DRG) neurons were planted and cultured; the configuration and growth characters of DRG neurons were observed through inverted microscope.

  6. Evaluation of Carbohydrates in Natural and Cultured Cordyceps by Pressurized Liquid Extraction and Gas Chromatography Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jia Guan

    2010-06-01

    Full Text Available Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose, xylose, mannose, glucose, galactose, mannitol, fructose and sorbose in 13 samples of natural and cultured Cordyceps were qualitatively and quantitatively analyzed and compared with myo-inositol hexaacetate as internal standard. The results showed that natural C. sinensis contained more than 7.99% free mannitol and a small amount of glucose, while its polysaccharides were usually composed of mannose, glucose and galactose with a molar ratio of 1.00:16.61~3.82:1.60~1.28. However, mannitol in cultured C. sinensis and cultured C. militaris were less than 5.83%, and free glucose was only detected in a few samples, while their polysaccharides were mainly composed of mannose, glucose and galactose with molar ratios of 1.00:3.01~1.09:3.30~1.05 and 1.00:2.86~1.28:1.07~0.78, respectively. Natural and cultured Cordyceps could be discriminated by hierarchical clustering analysis based on its free carbohydrate contents.

  7. Optimization of Liquid Fermentation Conditions and Protein Nutrition Evaluation of Mycelium from the Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes).

    Science.gov (United States)

    Gang, Jie; Liu, Han; Liu, Yanhong

    2016-01-01

    Cordyceps militaris is a well-known traditional Chinese medicinal mushroom. In this study, the mycelium of C. militaris was cultured using liquid fermentation technology and the culture medium components were optimized by the orthogonal test method. Our results showed that the optimal medium combination for the mycelium growth is 3% glucose, 3% peptone, 0.1% MgSO4, and 0.2% KH2PO4 The international general nutritional assessment method was applied to the overall evaluation of the protein nutrition value of submerged cultivated mycelium and fruit body of C. militaris. The protein contents in C. militaris mycelium and fruit body are 21.10% and 18.47%, respectively. The first limiting amino acids of C. militaris mycelium and fruit bodies are the sulfur-containing amino acids (methionine and cysteine), and the second limiting amino acid is isoleucine. The quality of amino acids from submerged cultivated mycelium and fruit body from C. militaris was also evaluated by amino acid score (AAS), chemical score (CS), essential amino acid index (EAAI), biological value (BV), nutritional index (NI), and score of ratio coefficient of amino acid (SRCAA). Our data demonstrate that AAS, CS, EAAI, BV, NI, and SRCAA scores of the submerged cultivated mycelium proteins are 62.41, 38.74, 88.37, 84.63, 18.61, and 25.57, respectively, whereas the fruit body proteins are 37.11, 34.59, 61.92, 55.79, 11.44, and 68.51, respectively. The protein content of C. militaris mycelium has higher nutrition value than that of fruit body protein, which holds the promise for future further development. Our study provides the optimal culture conditions and the essential nutritional information of medicinal species, C. militaris.

  8. IN-VITRO CULTURE FOR REGENERATION OF Melia azedarach L. USING AGITATED LIQUID MEDIUM

    Directory of Open Access Journals (Sweden)

    Arif Nirsatmanto

    2006-07-01

    Full Text Available This study investigated the applicability of liquid medium in direct organogenesis of in-vitro culture of Melia azedarach L. Explants were collected from in-vitro multiplication originating from aseptically germinated seedling and from a 48 - years old mature tree. For adventitious shoot differentiation, 2 mm length of excised explants were cultured on liquid medium of MS (Murashige and Skoog's basal medium supplemented with 28 combinations of hormone BAP (6-benzylaminopurine and NAA (á- naphthaleneacetic acid. Differentiated shoots were subsequently cultured for shoot elongation in solid medium using MS basal medium supplemented with hormone BAP individually as well as in combinations with NAA. Finally, rooting culture were done using MS medium supplemented with IBA (3  indolebutyric acid. The results showed that the rate of shoot organogenesis of M. azedarach could be obtained through agitated liquid medium culture technique. The combination of hormone BAP 0.1-1 µM and NAA 0.01-0.1 µM are induced more adventitious shoot at a rate of 5 shoots / 2 mm length size of explants are transferring into rooting medium containing IBA 4.92 µM.

  9. Liquid perfluorochemical-supported hybrid cell culture system for proliferation of chondrocytes on fibrous polylactide scaffolds.

    Science.gov (United States)

    Pilarek, Maciej; Grabowska, Iwona; Senderek, Ilona; Wojasiński, Michał; Janicka, Justyna; Janczyk-Ilach, Katarzyna; Ciach, Tomasz

    2014-09-01

    CP5 bovine chondrocytes were cultured on biodegradable electrospun fibrous polylactide (PLA) scaffolds placed on a flexible interface formed between two immiscible liquid phases: (1) hydrophobic perfluorochemical (PFC) and (2) aqueous culture medium, as a new way of cartilage implant development. Robust and intensive growth of CP5 cells was achieved in our hybrid liquid-solid-liquid culture system consisting of the fibrous PLA scaffolds in contrast to limited growth of the CP5 cells in traditional culture system with PLA scaffold placed on solid surface. The multicellular aggregates of CP5 cells covered the surface of PLA scaffolds and the chondrocytes migrated through and overgrew internal fibers of the scaffolds. Our hybrid culture system simultaneously allows the adhesion of adherent CP5 cells to fibers of PLA scaffolds as well as, due to use of phase of PFC, enhances the mass transfer in the case of supplying/removing of respiratory gases, i.e., O2 and CO2. Our flexible (independent of vessel shape) system is simple, ready-to-use and may utilize a variety of polymer-based scaffolds traditionally proposed for implant development.

  10. Optimal light for greenhouse culture of American ginseng seedlings

    Directory of Open Access Journals (Sweden)

    John T.A. Proctor

    2017-07-01

    Full Text Available Three greenhouse experiments with American ginseng seedlings growing under light levels from 4.8% to 68% showed a quadratic response for root dry weight, giving an optimal root dry weight of 239 mg (range 160–415 mg at an optimal light level of 35.6% (range 30.6–43.2%.

  11. Optimization and application of homogeneous liquid-liquid extraction in preconcentration of copper (II) in a ternary solvent system

    Energy Technology Data Exchange (ETDEWEB)

    Farajzadeh, Mir Ali [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: farajzade@yahoo.com; Bahram, Morteza [Department of Chemistry, Faculty of Science, Urmia University, Urmia (Iran, Islamic Republic of); Zorita, Saioa [Department of Analytical Chemistry, University of Lund, P.O. Box 124, 221 00 Lund (Sweden); Mehr, Behzad Ghorbani [Department of Chemistry, Faculty of Science, Urmia University, Urmia (Iran, Islamic Republic of)

    2009-01-30

    In this study a homogeneous liquid-liquid extraction based on the Ph-dependent phase-separation process was investigated using a ternary solvent system (water-acetic acid-chloroform) for the preconcentration of Cu{sup 2+} ions. 8-Hydroxy quinoline was used as the chelating agent prior to its extraction. Flame atomic absorption spectrophotometry using acetylene-air flame was used for the quantitation of analyte after preconcentration. The effect of various experimental parameters in extraction step was investigated using two optimization methods, one variable at a time and central composite design. The experimental design was done at five levels of operating parameters. Nearly the same optimized results were obtained using both methods: sample size, 5 mL; volume of NaOH 10 M, 2 mL; chloroform volume, 300 {mu}L; 8-hydroxy quinoline concentration more than 0.01 M and salt amount did not affect the extraction significantly. Under the optimum conditions the calibration graph was linear over the range 10-2000 {mu}g L{sup -1}. The relative standard deviation was 7.6% for six repeated determinations (C = 500 {mu}g L{sup -1}). Furthermore, the limit of detection (S/N = 3) and limit of quantification (S/N = 10) of the method were obtained as 1.74 and 6 {mu}g L{sup -1}, respectively.

  12. Culture medium optimization for pigment production with RSM method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Response surface methodology was used to optimize a medium for a red-pigmented marine bacterium S-9801 strain (Flavobacterium sp.). In the first optimization step the influence of yeast extract, peptone, glucose and sodium chloride on pigment production was evaluated using a fractional factorial design. Pigment production was positively influenced by glucose and sodium chloride while other components had no significant effect. In the second step the path of steepest ascent was used to approach the optimal region of the medium composition. In the third step the optimal concentration of glucose and sodium chloride was determined by a central composite design and response analysis. The optimized medium allowed pigment production (A 535~650) to be increased from 0.137 to0.559, being 320% higher than the original medium.

  13. Optimization and validation of liquid-liquid extraction with low temperature partitioning for determination of carbamates in water

    Energy Technology Data Exchange (ETDEWEB)

    Machado Goulart, Simone; Domingos Alves, Renata; Neves, Antonio Augusto; Queiroz, Jose Humberto de; Conde de Assis, Tamires [Departamento de Quimica, Universidade Federal de Vicosa, Vila Gianetti, Casa 24, 36 570-000 Vicosa, MG (Brazil); Queiroz, Maria Eliana L.R. de, E-mail: meliana@ufv.br [Departamento de Quimica, Universidade Federal de Vicosa, Vila Gianetti, Casa 24, 36 570-000 Vicosa, MG (Brazil)

    2010-06-25

    Using a 2{sup 3} experimental design, liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for analysis of three carbamates (aldicarb, carbofuran and carbaryl) in water samples. In this method, 2.0 mL of sample is placed in contact with 4.0 mL of acetonitrile. After agitation, the sample is placed in a freezer for 3 h for phase separation. The organic extract is analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). For validation of the technique, the following figures of merit were evaluated: accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity. Extraction recovery percentages of the carbamates aldicarb, carbofuran and carbaryl were 90%, 95% and 96%, respectively. Even though extremely low volumes of sample and solvent were used, the extraction method was selective and the detection and quantification limits were between 5.0 and 10.0 {mu}g L{sup -1}, and 17.0 and 33.0 {mu}g L{sup -1}, respectively.

  14. Quantitative proteome analysis of Streptomyces coelicolor Nonsporulating liquid cultures demonstrates a complex differentiation process comparable to that occurring in sporulating solid cultures

    DEFF Research Database (Denmark)

    Manteca, Angel; Jung, Hye R; Schwämmle, Veit

    2010-01-01

    Streptomyces species produce many clinically important secondary metabolites and present a complex developmental cycle that includes programmed cell death (PCD) phenomena and sporulation. Industrial fermentations are usually performed in liquid cultures, conditions in which Streptomyces strains...... of the different developmental stages in liquid and solid S. coelicolor cultures, in order to give new insights in Streptomyces biology, and improve industrial fermentations. Using iTRAQ labeling and LC-MS/MS analysis of peptides, we demonstrate that differentiation in S. coelicolor liquid cultures is comparable...

  15. Optimization of liquid-liquid extraction of biosurfactants from corn steep liquor.

    Science.gov (United States)

    Vecino, X; Barbosa-Pereira, L; Devesa-Rey, R; Cruz, J M; Moldes, A B

    2015-09-01

    In this work, the optimization of the operational conditions for the chloroform-based extraction of surface-active compounds from corn steep liquor (CSL) was carried out and the nutritional properties of the remnant aqueous phase (CSL-less biosurfactant) was evaluated as microbial fermentation medium. The optimal conditions to obtain biosurfactants from CSL were as follows: chloroform/CSL ratio 2 (v/v), 56 °C at extraction times >30 min. At the optima conditions, 100 % of biosurfactant extract can be obtained from CSL, obtaining 12.0 ± 0.5 g of biosurfactant extract/Kg of CSL. The critical micelle concentration (CMC) of the biosurfactant extract was 399.4 mg L(-1). This value is similar to the CMC of cetrimonium bromide (CTAB), a cationic surfactant used in the formulation of nanoparticles. The extraction of biosurfactant can be also carried out at room temperature although in this case, the extraction yield decreased about 15 %. The extraction of surface-active compounds from agroindustrial streams can suppose important advances for the bio-based surfactants industry. Biosurfactants obtained in this work are not only more eco-friendly than chemical detergents but also can be cost competitive with its chemical counterparts. Furthermore, after the extraction of surface-active compounds, CSL-less biosurfactant was found to be suitable as nutritional supplement for lactic acid bacteria, maintaining its nutritional properties in comparison with regular CSL.

  16. Optimizing of Culture Condition in Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Yan-Fang ZHANG; Huai-Qing CHEN; Hua HUANG

    2005-01-01

    @@ 1 Introduction Bioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world.

  17. SAFETY CULTURE ASSESSMENT – OPTIMIZATION OF EXISTING PRACTICE

    Directory of Open Access Journals (Sweden)

    Mirela Valenta Grebenšek

    2015-12-01

    Full Text Available Improving aviation safety has always been a priority for the aviation industry. While in recent decades the reliability of machinery and computers dramatically improved the reliability of the people and the organizational aspect of safety did not change much. Many of air accident investigations have shown that one of the causal factors, which increase the probability and severity of accidents, is exactly poor safety culture. The purpose of this paper is to present the concept of safety culture assessment and the overview and review of different methods of measuring the safety culture in aviation. This research provides the suggestion that by use of different methods of assessment (evaluation of the results, more credible insight into the level of safety culture in the organization can be obtained. It also provides an understanding of how measurement systems in order to guide future performance can be used proactively.

  18. Optimization of Culture of Leptospira from Humans with Leptospirosis▿

    Science.gov (United States)

    Wuthiekanun, Vanaporn; Chierakul, Wirongrong; Limmathurotsakul, Direk; Smythe, Lee D.; Symonds, Meegan L.; Dohnt, Michael F.; Slack, Andrew T.; Limpaiboon, Roongreung; Suputtamongkol, Yupin; White, Nicholas J.; Day, Nicholas P. J.; Peacock, Sharon J.

    2007-01-01

    A prospective study of 989 patients with acute febrile illness was performed in northeast Thailand to define the yield of Leptospira from four different types of blood sample. Based on a comparison of the yields from whole blood, surface plasma, deposit from spun plasma, and clotted blood samples from 80 patients with culture-proven leptospirosis, we suggest a sampling strategy in which culture is performed using whole blood and deposit from spun plasma. PMID:17301285

  19. Optimization of the Separation of Quinolines in Micellar Liquid Chromatography by Experimental Design and Regression Models

    Institute of Scientific and Technical Information of China (English)

    HADJMOHAMMADI,M.R.; KAMEL,K.

    2008-01-01

    The chemometrics approach was applied to the optimization of separation of quinolines in micellar liquid tigated by means of multivariate analysis. The factors considered were the concentration of sodium dodecyl sulfate (SDS), the organic modifier concentration and the length of its alkyl chain, and pH of the mobile phase. The ex-periments were performed according to a face centered cube response surface experimental design. In order to op-timize the separation a Pareto-optimality method was employed. The models were verified, because a good agree-ment was observed between the predicted and experimental values of the chromatographic response function in the optimal condition. The obtained regression models were characterized by both descriptive and predictive ability (R2≥0.97 and R2cv≥0.92) and allowed the chromatographic separation of the quinolines with a good resolution and a total analysis time of 50 min.

  20. Validated Liquid Culture Monitoring System for Lifespan Extension of Caenorhabditis elegans through Genetic and Dietary Manipulations.

    Science.gov (United States)

    Win, Myat Thu Thu; Yamamoto, Yasuhiko; Munesue, Seiichi; Han, Dong; Harada, Shin-Ichi; Yamamoto, Hiroshi

    2013-08-01

    Nutritional and genetic factors influence aging and life expectancy. The reduction of food intake without malnutrition, referred to caloric restriction (CR), has been shown to increase lifespan in a wide variety of species. The nematode Caenorhabditis elegans (C. elegans) is one of the principle models with which to study the biology of aging and search for anti-aging compounds. In this study, we validated and optimized a high-throughput liquid culture system to monitor C. elegans lifespan with minimized mechanical stress. We used alive and ultraviolet (UV)-killed Escherichia coli (E. coli) OP50 at 10(8) or 10(9) colony-forming units (cfu)/ml to feed Bristol N2 wild-type (WT) and mutant worms of a well-characterized insulin/insulin-like growth factor signaling (ILS) pathway: the insulin receptor homolog daf-2 (e1370), phosphatidylinositol 3-kinase age-1 (hx546), and transcriptional factor FOXO homolog daf-16 (mu86 and mgDf50). Compared with alive E. coli at 10(9) cfu/ml, supplementations of alive E. coli at 10(8) cfu/ml or UV-killed E. coli at 10(9) cfu/ml dramatically prolonged lifespan in WT and age-1 mutants, and to a lesser extent, in daf-2 and daf-16 mutants, suggesting that signaling pathways in CR and ILS do not overlap fully. Feeding 10(8) cfu/ml UV-killed E. coli, which led to maximally saturated longevity in WT and daf-2 mutant, can prolonged lifespan in age-1, but not daf-16, mutants. This approach will be useful for investigating the biology of aging, physiological responses and gene functions under CR conditions and also for screening pharmacologic compounds to extend lifespan or affect other biologic processes.

  1. Optical design and multiobjective optimization of miniature zoom optics with liquid lens element.

    Science.gov (United States)

    Sun, Jung-Hung; Hsueh, Bo-Ren; Fang, Yi-Chin; MacDonald, John; Hu, Chao-Chang

    2009-03-20

    We propose an optical design for miniature 2.5x zoom fold optics with liquid elements. First, we reduce the volumetric size of the system. Second, this newly developed design significantly reduces the number of moving groups for this 2.5x miniature zoom optics (with only two moving groups compared with the four or five groups of the traditional zoom lens system), thanks to the assistance of liquid lens elements in particular. With regard to the extended optimization of this zoom optics, relative illuminance (RI) and the modulation transfer function (MTF) are considered because the more rays passing through the edge of the image, the lower will be the MTF, at high spatial frequencies in particular. Extended optimization employs the integration of the Taguchi method and the robust multiple criterion optimization (RMCO) approach. In this approach, a Pareto optimal robust design solution is set with the aid of a certain design of the experimental set, which uses analysis of variance results to quantify the relative dominance and significance of the design factors. It is concluded that the Taguchi method and RMCO approach is successful in optimizing the RI and MTF values of the fold 2.5x zoom lens system and yields better and more balanced performance, which is very difficult for the traditional least damping square method to achieve.

  2. Optimization and Sizing for Propulsion System of Liquid Rocket Using Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    Saqlain Akhtar; He Lin-shu

    2007-01-01

    Flight vehicle conceptual design appears to be a promising area for application of the Genetic Algorithm (GA) as an approach to help to automate part of the design process. This computational research effort strives to develop a propulsion system design strategy for liquid rocket to optimize take-off mass, satisfying the mission range under the constraint of axial overload. The method by which this process is accomplished by using GA as optimizer is outlined in this paper. Convergence of GA is improved by introducing initial population based on Design of Experiments Technique.

  3. A Class of Optimal Portfolio Liquidation Problems with a Linear Decreasing Impact

    Directory of Open Access Journals (Sweden)

    Jiangming Ma

    2017-01-01

    Full Text Available A problem of an optimal liquidation is investigated by using the Almgren-Chriss market impact model on the background that the n agents liquidate assets completely. The impact of market is divided into three components: unaffected price process, permanent impact, and temporary impact. The key element is that the variable temporary market impact is analyzed. When the temporary market impact is decreasing linearly, the optimal problem is described by a Nash equilibrium in finite time horizon. The stochastic component of the price process is eliminated from the mean-variance. Mathematically, the Nash equilibrium is considered as the second-order linear differential equation with variable coefficients. We prove the existence and uniqueness of solutions for the differential equation with two boundaries and find the closed-form solutions in special situations. The numerical examples and properties of the solution are given. The corresponding finance phenomenon is interpreted.

  4. Growth of plant root cultures in liquid- and gas-dispersed reactor environments.

    Science.gov (United States)

    McKelvey, S A; Gehrig, J A; Hollar, K A; Curtis, W R

    1993-01-01

    The growth of Agrobacterium transformed "hairy root" cultures of Hyoscyamus muticus was examined in various liquid- and gas-dispersed bioreactor configurations. Reactor runs were replicated to provide statistical comparisons of nutrient availability on culture performance. Accumulated tissue mass in submerged air-sparged reactors was 31% of gyratory shake-flask controls. Experiments demonstrate that poor performance of sparged reactors is not due to bubble shear damage, carbon dioxide stripping, settling, or flotation of roots. Impaired oxygen transfer due to channeling and stagnation of the liquid phase are the apparent causes of poor growth. Roots grown on a medium-perfused inclined plane grew at 48% of gyratory controls. This demonstrates the ability of cultures to partially compensate for poor liquid distribution through vascular transport of nutrients. A reactor configuration in which the medium is sprayed over the roots and permitted to drain down through the root tissue was able to provide growth rates which are statistically indistinguishable (95% T-test) from gyratory shake-flask controls. In this type of spray/trickle-bed configuration, it is shown that distribution of the roots becomes a key factor in controlling the rate of growth. Implications of these results regarding design and scale-up of bioreactors to produce fine chemicals from root cultures are discussed.

  5. Evaluation of Quantity and Hyperhydricity of Cocoa Somatic Embryo Obtained from Solid Culture, Liquid Culture, and Sequence Subculture

    Directory of Open Access Journals (Sweden)

    Sulistyani Pancaningtyas

    2013-05-01

    Full Text Available Research  aimed  to  study  the  effect  of  solid  cultureliquid  culture,  and sequence  subculture  on  quantity  and  hyperhydricity  of  somatic  embryo  wascarried  out  at  Laboratory  of  Biotechnology,  Indonesian  Coffee  and  Cocoa Research  Institute.  Materials  used  in  this  study  were  embryogenic  callitransferred  on  somatic  embryos  expression  both  in  solid  and  liquid  media with  the  same  media  composition,  namely  MS  medium  with  the  addition  ofAdenine  (0.025  mg/L.  Gelling  agent  used  in  solid  media  was  gelrite  (3  g/L. Clones used in this study was Sca 6. This research consisted of two trials, namely1  effect  of  medium  type  (solid  and  liquid,  and  2  sequence  subculture  (four subcultures.  This  results  showed  that  the  production  of  somatic  embryosin  liquid  medium  was  higher  than  in  the  solid  medium.  Regeneration  of somatic  embryos  on  solid  medium  culture  showed  the  highest  percentage  of abnormality  embryos  due  to  hyperhydricity  at  the  cotyledonary  phase  60%. Meanwhile,  the  regeneration  of  somatic  embryos  in  liquid  culture  showed the  highest  percentage  of  abnormality  embryos  due  to   hyperhydricity  at the  globular  and  cotyledonary  phase  37%.  Frequent  subculture  increased abnormal embryos  and  decreased  the  number of  somatic  embryos.Key words: Cacao, hyperhydricity,  somatic embryos,  solid  cultureliquid  culture,  subculture,  in  vitro.

  6. Performance optimization of optical switches in ferroelectric liquid crystals and polymers operating at 1550 nm

    Science.gov (United States)

    Asquini, Rita; Gizzi, Claudio; Beccherelli, Romeo; d'Alessandro, Antonio

    2004-01-01

    A multilayer structure realizing an optical switch with ferroelectric liquid crystal, polymeric buffers and waveguides has been analyzed at the wavelength of 1550 nm, focusing on fabrication and design tolerances. The used liquid crystal FELIX-M4851-025 from Clariant is aligned by Nylon6 and embedded between two polymeric waveguides. ITO is deposited on quartz substrates to apply voltage to the cell and polymeric buffers are employed to reduce ITO absorption losses. The polymers consisted of poly(pentafluorostyrene-co-glycidyl methacrylate). Light is switched between the optical waveguides by reorienting the liquid crystal. Optimization in terms of optical losses and extinction ratios was carried out by varying layer thicknesses, refractive indices of waveguides and buffers, and the angle α between the normal to the smectic layers and the propagation direction. An optimized device with α = 51°, refractive indices of 1.475 and 1.462, thicknesses of 3 and 6 μm for waveguides and buffer, respectively and 4.4 μm for the liquid crystal layer, exhibits an extinction ratio of 59.6 dB with losses as low as 0.8 dB for a length of only 174 μm. A device design using single mode channel waveguides for optical switching matrices has been also carried out.

  7. Optimal Extraction of Gallic Acid from Suaeda glauca Bge. Leaves and Enhanced Efficiency by Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Xin-Hong Wang

    2016-01-01

    Full Text Available The ultrasound-assisted extraction (UAE was initially applied to extract gallic acid from Suaeda glauca Bge. using 70% ethanol as extraction solvent. Temperature, liquid-solid ratio, and extraction time were optimized by response surface methodology (RSM, obtaining maximum levels of gallic acid (6.30 mg·g−1 at 51°C, 19.52 mL·g−1, and 42.68 min, respectively. The obtained model was statistically significant (p<0.0001. The verification experiments at the optimum conditions yielded gallic acid for 6.21 mg·g−1. Subsequently, under optimal conditions, four ionic liquids were used to extract gallic acid from Suaeda glauca Bge. The results indicated that the presence of 1-hexyl-3-methylimidazolium chloride allowed increasing the EE of gallic acid up to 8.90 mg·g−1. This might be interpreted in terms of the molecular interaction between ionic liquid and gallic acid. The use of ionic liquids involves a stronger gallic acid extraction capacity than conventional organic volatile solvents. A promising alternative process is proposed for the extraction of gallic acid of Suaeda glauca Bge.

  8. Optimizing a culture medium for biomass and phenolic compounds production using Ganoderma lucidum

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Zárate-Chaves

    2013-01-01

    Full Text Available The present work was aimed at optimizing a culture medium for biomass production and phenolic compounds by using Ganoderma lucidum. The culture was optimized in two stages; a Plackett-Burman design was used in the first one for identifying key components in the medium and a central composite design was used in the second one for optimizing their concentration. Both responses (biomass and phenolic compounds were simultaneously optimized by the latter methodology regarding desirability, and the optimal concentrations obtained were 50.00 g/L sucrose, 13.29 g/L yeast extract and 2.99 g/L olive oil. Maximum biomass production identified in these optimal conditions was 9.5 g/L and that for phenolic compounds was 0.0452 g/L, this being 100% better than that obtained in the media usually used in the laboratory. Similar patterns regarding chemical characterization and biological activity towards Aspergillus sp., from both fruiting body and mycelium-derived secondary metabolites and extracts obtained in the proposed medium were observed. It was shown that such statistical methodologies are useful for optimizing fermentation and, in the specific case of G. lucidum, optimizing processes for its production and its metabolites in submerged culture as an alternative to traditional culture.

  9. In vitro zygotic embryo culture of Pinus peuce Gris.: Optimization of culture conditions affecting germination and early seedling growth

    Directory of Open Access Journals (Sweden)

    Stojičić Dragana

    2012-01-01

    Full Text Available This study reports a protocol for the germination and early seedling growth of Pinus peuce Gris. using zygotic embryo culture. In order to overcome seed dormancy and optimize organogenesis, the effect of nutritional, plant growth regulatory and physical factors on in vitro germination and growth of isolated mature zygotic embryos of P. peuce were investigated.

  10. Liquid scintillator composition optimization for use in ultra-high energy cosmic ray detector systems

    Science.gov (United States)

    Beznosko, Dmitriy; Batyrkhanov, Ayan; Iakovlev, Alexander; Yelshibekov, Khalykbek

    2017-06-01

    The Horizon-T (HT) detector system and the currently under R&D HT-KZ detector system are designed for the detection of Extensive Air Showers (EAS) with energies above ˜1016 eV (˜1017 eV for HT-KZ). The main challenges in both detector systems are the fast time resolutions needed for studying the temporary structure of EAS, and the extremely wide dynamic range needed to study the spatial distribution of charged particles in EAS disks. In order to detect the low-density of charged particles far from the EAS axis, a large-area detector is needed. Liquid scintillator with low cost would be a possible solution for such a detector, including the recently developed safe and low-cost water-based liquid scintillators. Liquid organic scintillators give a fast and high light yield (LY) for charged particle detection. It is similar to plastic scintillator in properties but is cost effective for large volumes. With liquid scintillator, one can create detection volumes that are symmetric and yet retain high LY detection. Different wavelength shifters affect the scintillation light by changing the output spectrum into the best detection region. Results of the latest studies of the components optimization in the liquid scintillator formulae are presented.

  11. Pre-culturing of nodal explants in thidiazuron supplemented liquid medium improves in vitro shoot multiplication of Cassia angustifolia.

    Science.gov (United States)

    Siddique, I; Abdullwahab Bukhari, N; Perveen, K; Siddiqui, I; Anis, M

    2013-09-01

    An in vitro propagation system for Cassia angustifolia Vahl. has been developed. Due to the presence of sennosides, the demand of this plant has increased manyfold in global market. Multiple shoots were induced by culturing nodal explants excised from mature plants on a liquid Murashige and Skoog [8] medium supplemented with 5-100 μM of thidiazuron (TDZ) for different treatment duration (4, 8, 12 and 16 d). The optimal level of TDZ supplemented to the culture medium was 75 μM for 12 d induction period followed by subculturing in MS medium devoid of TDZ as it produced maximum regeneration frequency (87%), mean number of shoots (9.6 ± 0.33) and shoot length (4.4 ± 0.46 cm) per explant. A culture period longer than 12 d with TDZ resulted in the formation of fasciated or distorted shoots. Ex vitro rooting was achieved when the basal cut end of regenerated shoots was dipped in 200 μM indole-3-butyric acid (IBA) for half an hour followed by their transplantation in plastic pots filled with sterile soilrite where 85% plantlets grew well and all exhibited normal development. The present findings describe an efficient and rapid plant regeneration protocol that can further be used for genetic transformation studies.

  12. The benefits of social influence in optimized cultural markets.

    Science.gov (United States)

    Abeliuk, Andrés; Berbeglia, Gerardo; Cebrian, Manuel; Van Hentenryck, Pascal

    2015-01-01

    Social influence has been shown to create significant unpredictability in cultural markets, providing one potential explanation why experts routinely fail at predicting commercial success of cultural products. As a result, social influence is often presented in a negative light. Here, we show the benefits of social influence for cultural markets. We present a policy that uses product quality, appeal, position bias and social influence to maximize expected profits in the market. Our computational experiments show that our profit-maximizing policy leverages social influence to produce significant performance benefits for the market, while our theoretical analysis proves that our policy outperforms in expectation any policy not displaying social signals. Our results contrast with earlier work which focused on showing the unpredictability and inequalities created by social influence. Not only do we show for the first time that, under our policy, dynamically showing consumers positive social signals increases the expected profit of the seller in cultural markets. We also show that, in reasonable settings, our profit-maximizing policy does not introduce significant unpredictability and identifies "blockbusters". Overall, these results shed new light on the nature of social influence and how it can be leveraged for the benefits of the market.

  13. Medium optimization for protopectinase production by batch culture ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-11

    Nov 11, 2011 ... its ability to form aqueous gels, dispersion stabilizer. There are two main ... Protopectinases (PPases) are used as heterogeneous group of ... one day, and then maintained at 4°C. The seed culture medium contained (g/L): ...

  14. Toxoplasma gondii from liquid nitrogen for continuous cell culture: methods to maximise efficient retrieval.

    Science.gov (United States)

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (> or = 1 x 10(6) tachyzoites/mL, > or = 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75 cm2 flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  15. Reversed-phase dispersive liquid-liquid microextraction with central composite design optimization for preconcentration and HPLC determination of oleuropein.

    Science.gov (United States)

    Hashemi, Payman; Raeisi, Fatemeh; Ghiasvand, Ali Reza; Rahimi, Akram

    2010-03-15

    A reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) method was developed for the preconcentration and direct HPLC determination of oleuropein in olive's processing wastewater (OPW) and olive leaves extracts. In conventional DLLME, the sedimented phase is a micro-drop of a chlorinated organic solvent that is not compatible with RP-HPLC. Therefore, solvent evaporation and reconstitution with an appropriate solvent is often required. In RP-DLLME, this problem was overcome by overturning the solvent polarity in the ordinary DLLME and replacing the organic solvent with water. A central composite chemometrics design was used for multivariate optimization of the effects of five different parameters influencing the extraction efficiency of the method. In the optimized conditions, a mixture of 1.4 mL of an ethyl acetate extract of sample and 40 microL water (pH 5.0) was rapidly injected into 5.3 mL of cyclohexane. After centrifugation of the formed cloudy mixture, a micro-drop of the aqueous phase was sedimented at the conical bottom of the centrifuge tube. This phase, that contained the preconcentrated and partially purified analyte, was directly injected into an RP-HPLC column for analysis. A mean extraction recovery of 102.5 (+/-4.5) % with enrichment factors exceeding 38, was obtained for five replicated analysis. The detection limit of the method (3 sigma) for OE was 0.02 microg L(-1) for OPW and 2 x 10(-3) mg kg(-1) for olive leaves samples. The results showed that, RP-DLLME is a promising technique which is quick, easily operated and can be directly coupled to HPLC.

  16. Dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for determination of benzoate and sorbate in yogurt drinks and method optimization by central composite design.

    Science.gov (United States)

    Kamankesh, Marzieh; Mohammadi, Abdorreza; Tehrani, Zohreh Modarres; Ferdowsi, Roohallah; Hosseini, Hedayat

    2013-05-15

    A new method based on dispersive liquid-liquid microextraction (DLLME) followed by high-performance liquid chromatography (HPLC) for determination of benzoate and sorbate salts in yogurt drinks was developed. The effective parameters in DLLME process, including volume of extraction and disperser solvents, pH and salt effect, were optimized using response surface methodology (RSM) based on central composite design. The yogurt drink samples were extracted using NaOH and Carrez solutions (potassium hexaferrocyanide and zinc acetate) were used for sedimentation of proteins. For DLLME, a mixture of extraction solvent (1-octanol) and disperser solvent (ethanol) was rapidly injected into the sample solution by syringe and cloudy solution is formed. Subsequently, the upper 1-octanol layer was analyzed by HPLC. The detection limits for benzoate and sorbate were 0.06 ng mL(-1) and 0.15 ng mL(-1), respectively. The relative standard deviations (RSD) for seven analyses were 4.96% for benzoate and 4.58% for sorbate. The proposed method demonstrated good linearity and high enrichment factor. A clean separation and good chromatogram is readily achieved without the presence of matrix interference. A comparison of this method with previous methods demonstrated that the proposed method is an accurate, rapid and reliable sample-pretreatment method that gives very good enrichment factors and detection limits for extracting and determining sorbate and benzoate in yogurt drink samples.

  17. Model optimization method and connected-pipe experiment of a liquid fuel ramjet engine

    Institute of Scientific and Technical Information of China (English)

    MA Qian-rong; GUO Xin; WU Hu; CHOU Qian

    2013-01-01

    The optimization method of a mathematical model and connected-pipe experimental technique for a test in altitude test facility (ATF) of a liquid fuel ramjet engine was researched.The optimization of the simple mathematical model was divided into two steps.Firstly,using the test engine's geometry configuration size data,a preliminary adjustment was done.Secondly,using experimental test data,the components' experiential coefficients were modified appropriately.Emphasis was laid on the simulation technique of flight condition and parameters measurement method.The experimental technique was applied to a ramjet ATF test successfully.The comparison results show that the optimized-model has higher precision and the nozzle gross thrust difference drops from 12% to about 4%.

  18. Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability.

    Science.gov (United States)

    Dijkstra, Camelia E; Larkin, Oliver J; Anthony, Paul; Davey, Michael R; Eaves, Laurence; Rees, Catherine E D; Hill, Richard J A

    2011-03-06

    Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

  19. High Efficiency Secondary Somatic Embryogenesis in Hovenia dulcis Thunb. through Solid and Liquid Cultures

    Directory of Open Access Journals (Sweden)

    Jingli Yang

    2013-01-01

    Full Text Available Embryogenic callus was obtained from mature seed explants on medium supplemented with 2,4-dichlorophenoxyacetic acid. Primary somatic embryos (SEs can only develop into abnormal plants. Well-developed SEs could be obtained through secondary somatic embryogenesis both in solid and liquid cultures. Temperature strongly affected induction frequency of secondary embryogenesis. Relatively high temperature (30∘C and germinated SEs explants were effective for induction of secondary somatic embryos, and low temperature (20∘C was more suitable for further embryo development, plantlet conversion, and transplant survival. Somatic embryos formed on agar medium had larger cotyledons than those of embryos formed in liquid medium. Supplementing 0.1 mg L−1 6-benzyladenine (BA was effective for plant conversion; the rate of plant conversion was 43.3% in somatic embryos from solid culture and 36.5% in embryos from liquid culture. In vitro plants were successfully acclimatized in the greenhouse. The protocol established in this study will be helpful for large-scale vegetative propagation of this medicinal tree.

  20. Growth of Physarum gyrosum on Agar Plates and in Liquid Culture1

    Science.gov (United States)

    Taylor, Richard L.; Mallette, M. F.

    1976-01-01

    The physical and nutritional requirements of the antibiotic-producing slime mold Physarum gyrosum were examined to develop a liquid medium for this myxomycete. Liquid culture is desired to expedite a useful scale of production of antibiotic materials for ease of isolation and structure study. Culture conditions were selected to favor antibiotic production rather than maximum growth. The medium devised consisted of 0.010 M potassium phosphate buffer (pH 6.0), 2% bakers' yeast, and 0.2% glucose and was supplemented with either 10−7 M hemoglobin (preferred) or 2.0 ml of live Escherichia coli per 100 ml of culture medium grown to a steady-state population in nutrient broth. The slime mold, which contained some E. coli carried along with the inoculum, was allowed to grow as a surface plasmodium at 20°C in the dark with weekly subculturing for stocks or for 10 days for antibiotic production. P. gyrosum produced the same antibiotic materials when grown in liquid medium as it did when grown on agar plates. A seeded plate disk assay against Bacillus cereus was employed to follow antibiotic activity. PMID:10830

  1. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation.

    Science.gov (United States)

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A; Bouquerel, Hélène

    2016-06-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L(-1) and 10% for 10 mBq L(-1). While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L(-1), a conservative experimental estimate is rather 5 mBq L(-1), corresponding to 0.14 fg g(-1). The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported.

  2. Intelligent Optimization of a Mixed Culture Cultivation Process

    Directory of Open Access Journals (Sweden)

    Petia Koprinkova-Hristova

    2015-04-01

    Full Text Available In the present paper a neural network approach called "Adaptive Critic Design" (ACD was applied to optimal tuning of set point controllers of the three main substrates (sugar, nitrogen source and dissolved oxygen for PHB production process. For approximation of the critic and the controllers a special kind of recurrent neural networks called Echo state networks (ESN were used. Their structure allows fast training that will be of crucial importance in on-line applications. The critic network is trained to minimize the temporal difference error using Recursive Least Squares method. Two approaches - gradient and heuristic - were exploited for training of the controllers. The comparison is made with respect to achieved improvement of the utility function subject of optimization as well as with known expert strategy for control the PHB production process.

  3. Statistical optimization of process parameters influencing the biotransformation of plant tannin into gallic acid under solid-liquid fermentation

    OpenAIRE

    Bibhu Prasad Panda; Rupa Mazumder; Rintu Banerjee

    2009-01-01

    Purpose : To optimize and produce gallic acid by biotransformation of plant tannin under solid-liquid fermentation. Materials and Methods : Optimization of different process parameters like temperature, relative humidity, pH of the liquid medium, fermentation period, volume of inoculum weight of substrate influencing gallic acid production from plant tannin were carried out by EVOP factorial method. Results : Maximum gallic acid yield of 93.29% was produced at 28ΊC, 70% relative humidity, pH ...

  4. Liquid Nitrogen (-196°C effect under pollen of some cultured or ornamental species

    Directory of Open Access Journals (Sweden)

    Sabina GLIGOR

    2006-05-01

    Full Text Available The criopreservation involve the stock of the vegetal material at low temperatures (-196°C in liquid nitrogen, in thermal conditions in which the division of cells and metabolic processes slow down, thus that the samplings may be conserved for long periods without suffering any genetic modifications. This stock technique is applied till present only on 80 vegetal species, keeping their seeds and vitrocultures preponderantly; researches were made regarding the maintenance of pollen in liquid nitrogen.The mature pollen, able to resist a higher degree of desiccation, may be conserved at low temperatures, without criopreservation. It was made researches on criopreservation of rise, maize, wheat, roses, sun flower and soy pollen. Our study purpose was to follow the impact of liquid nitrogen (-196°C about on viability of some cultured and ornamental species. The designed time of criopreservation it was 30 minutes and 7 days, using the TTC (tripheniltetrazole chloride method which allows testing the viability of vegetal material based on dehydrogenase activity.It was observed at Petunia hybrida species, that the pollen viability was low - in relevance with the witness represented from the pollen which was not resigned to the nitrogen liquid treatment - between percentage limits of 3.5-8%, in the case when the vegetal material was submersed 30 minutes in liquid nitrogen and 7.5-14.5% 7 days at (-196°C. The submersing of Nicotiana alata var. grandiflora species at 7 days, determined a low viability with 11.53%. The following two studied species Cucurbita and Hosta were proved to be the most resistant at submersing and maintenance in liquid nitrogen. The most affected pollen was Campsis radicans species. At Datura stramonium species was observed 2.59% a low viability of pollen, after 30 minutes of liquid nitrogen treatment, was 19.56%, after 7 days of submersing, the most pollen granules losing completely their viability.

  5. Irradiance optimization of outdoor microalgal cultures using solar tracked photobioreactors.

    Science.gov (United States)

    Hindersin, Stefan; Leupold, Marco; Kerner, Martin; Hanelt, Dieter

    2013-03-01

    Photosynthetic activity and temperature regulation of microalgal cultures (Chlorella vulgaris and Scenedesmus obliquus) under different irradiances controlled by a solar tracker and different cell densities were studied in outdoor flat panel photobioreactors. An automated process control unit regulated light and temperature as well as pH value and nutrient concentration in the culture medium. CO2 was supplied using flue gas from an attached combined block heat and power station. Photosynthetic activity was determined by pulse amplitude modulation fluorometry. Compared to the horizontal irradiance of 55 mol photons m(-2) d(-1) on a clear day, the solar tracked photobioreactors enabled a decrease and increase in the overall light absorption from 19 mol photons m(-2) d(-1) (by rotation out of direct irradiance) to 79 mol photons m(-2) d(-1) (following the position of the sun). At biomass concentrations below 1.1 g cell dry weight (CDW) L(-1), photoinhibition of about 35 % occurred at irradiances of ≥1,000 μmol photons m(-2) s(-1) photosynthetic active radiation (PAR). Using solar tracked photobioreactors, photoinhibition can be reduced and at optimum biomass concentration (≥2.3 g CDW L(-1)), the culture was irradiated up to 2,000 μmol photons m(-2) s(-1) to overcome light limitation with biomass yields of 0.7 g CDW mol photons(-1) and high photosynthetic activities indicated by an effective quantum yield of 0.68 and a maximum quantum yield of 0.80 (F v/F m). Overheating due to high irradiance was avoided by turning the PBR out of the sun or using a cooling system, which maintained the temperature close to the species-specific temperature optima.

  6. [The optimization of the nitric oxide quantitative analysis for its determination in the cultural medium of mammalian cell culture].

    Science.gov (United States)

    Akimov, M G; Fomina-Ageeva, E V; Bezuglov, V V

    2015-01-01

    The protocol for the quantitative analysis of nitric oxide as nitrite-ion suitable for determination of its production by a mammalian cell culture was developed. The optimal results were obtained using microvolume-adjusted Griess method after the preliminary reduction of NO3- to NO2- with non-activated cadmium. The protocol was verified on a rat glioma C6 cell culture. The developed method may be used for the nitric oxide determination in 96-well and 48-well microplates; the detection limit is 2.1 ± 0.1 μM for NO2- and 2.9 ± 0.1 μM for NO3-.

  7. Topology optimization for the design of folding liquid crystal elastomer actuators.

    Science.gov (United States)

    Fuchi, Kazuko; Ware, Taylor H; Buskohl, Philip R; Reich, Gregory W; Vaia, Richard A; White, Timothy J; Joo, James J

    2015-10-01

    Aligned liquid crystal elastomers (LCEs) are capable of undergoing large reversible shape change in response to thermal stimuli and may act as actuators for many potential applications such as self-assembly and deployment of micro devices. Recent advances in LCE patterning tools have demonstrated sub-millimetre control of director orientation, enabling the preparation of materials with arbitrarily complex director fields. However, without design tools to connect the 2D director pattern with the activated 3D shape, LCE design relies on intuition and trial and error. Here we present a design methodology to generate reliable folding in monolithic LCEs designed with topology optimization. The distributions of order/disorder and director orientations are optimized so that the remotely actuated deformation closely matches a target deformation for origami folding. The optimal design exhibits a strategy to counteract the mechanical frustration that may lead to an undesirable deformation, such as anti-clastic bending. Multi-hinge networks were developed using insights from the optimal hinge designs and were demonstrated through the fabrication and reversible actuation of a self-folding box. Topology optimization provides an important step towards leveraging the opportunities afforded by LCE patterning into functional designs.

  8. Enzyme-assisted extraction and ionic liquid-based dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for determination of patulin in apple juice and method optimization using central composite design.

    Science.gov (United States)

    Mohammadi, Abdorreza; Tavakoli, Rouya; Kamankesh, Marzieh; Rashedi, Hamid; Attaran, Abdolmohammad; Delavar, Mostafa

    2013-12-01

    A simple and highly sensitive analytical methodology for isolation and determination of patulin in apple-juice samples, based on enzyme-assisted extraction (EAE) and ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) was developed and optimized. Enzymes play essential roles in eliminating interference and increasing the extraction efficiency of patulin. Apple-juice samples were treated with pectinase and amylase. A mixture of 80 μL ionic liquid and 600 μL methanol (disperser solvent) was used for the IL-DLLME process. The sedimented phase was analyzed by high-performance liquid chromatography (HPLC). Experimental parameters controlling the performance of DLLME, were optimized using response surface methodology (RSM) based on central composite design (CCD). Under optimum conditions, the calibration curves showed high levels of linearity (R(2)>0.99) for patulin in the range of 1-200 ng g(-1). The relative standard deviation (RSD) for the seven analyses was 7.5%. The limits of detection (LOD) and limits of quantification (LOQ) were 0.15 ng g(-1) and 0.5 ng g(-1), respectively. The merit figures, compared with other methods, showed that new proposed method is an accurate, precise and reliable sample-pretreatment method that substantially reduces sample matrix interference and gives very good enrichment factors and detection limits for investigation trace amount of patulin in apple-juice samples.

  9. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-01

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures.

  10. Liquid chromatographic method for determination of water in soils and the optimization of anion separations by capillary zone electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Nancy [Iowa State Univ., Ames, IA (United States)

    1994-01-01

    A liquid chromatographic method for the determination of water in soil or clay samples is presented. In a separate study, the optimization of electrophoretic separation of alkylated phenolate ions was optimized by varying the pH and acetonitrile concentration of the buffer solutions.

  11. Dynamic analysis of a liquid droplet and optimization of helical angles for vortex drainage gas recovery

    Directory of Open Access Journals (Sweden)

    Xiaodong Wu

    2016-10-01

    Full Text Available Downhole vortex drainage gas recovery is a new gas production technology. So far, however, the forces and motions of liquid phase in the swirling flow field of wellbores during its field application have not been figured out. In this paper, the forces of liquid droplets in the swirling flow field of wellbores were analyzed on the basis of two-phase fluid dynamics theories. Then, the motion equations of fluid droplets along axial and radical directions were established. Magnitude comparison was performed on several typical acting forces, including Basset force, virtual mass force, Magnus force, Saffman force and Stokes force. Besides, the formula for calculating the optimal helical angle of vortex tools was established according to the principle that the vertical resultant force on fluid droplets should be the maximum. And afterwards, each acting force was comprehensively analyzed in terms of its origin, characteristics and direction based on the established force analysis model. Magnitude comparison indicates that the forces with less effect can be neglected, including virtual mass force, Basset force and convection volume force. Moreover, the vertically upward centrifugal force component occurs on the fluid droplets in swirling flow field instead of those in the conventional flow field of wellbores, which is favorable for the fluid droplets to move upward. The reliability of optimal helical angle calculation formula was verified by means of case analysis. It is demonstrated that with the decrease of well depth, the fluid-carrying capability of gas and the optimal helical angle increase. The research results in this paper have a guiding significance to the optimization design of downhole vortex tools and the field application of downhole vortex drainage gas recovery technology.

  12. Optimization of a feed medium for fed-batch culture of insect cells using a genetic algorithm

    NARCIS (Netherlands)

    Marteijn, R.C.L.; Jurrius, O.; Dhont, J.; Gooijer, de C.D.; Tramper, J.; Martens, D.E.

    2003-01-01

    Insect cells have been cultured for over 30 years, but their application is still hampered by low cell densities in batch fermentations and expensive culture media. With respect to the culture method, the fed-batch culture mode is often found to give the best yields. However, optimization of the

  13. Application of Sigmoidal Transformation Functions in Optimization of Micellar Liquid Chromatographic Separation of Six Quinolone Antibiotics.

    Science.gov (United States)

    Hadjmohammadi, Mohammadreza; Salary, Mina

    2016-03-01

    A chemometrics approach has been used to optimize the separation of six quinolone compounds by micellar liquid chromatography (MLC). A Derringer's desirability function, a multicriteria decision-making (MCDM) method, was tested for evaluation of two different measures of chromatographic performance (resolution and analysis time). The effect of three experimental parameters on a chromatographic response function (CRF) expressed as a product of two sigmoidal desirability functions was investigated. The sigmoidal functions were used to transform the optimization criteria, resolution and analysis time into the desirability values. The factors studied were the concentration of sodium dodecyl sulfate, butanol content and pH of the mobile phase. The experiments were done according to the face-centered cube central composite design, and the calculated CRF values were fitted to a polynomial model to correlate the CRF values with the variables and their interactions. The developed regression model showed good descriptive and predictive ability (R(2) = 0.815, F = 6.919, SE = 0.038, [Formula: see text]) and used, by a grid search algorithm, to optimize the chromatographic conditions for the separation of the mixture. The efficiency of prediction of polynomial model was confirmed by performing the experiment under the optimal conditions.

  14. Optimization of liquid jet system for laser-induced breakdown spectroscopy analysis.

    Science.gov (United States)

    Skočovská, Katarína; Novotný, Jan; Prochazka, David; Pořízka, Pavel; Novotný, Karel; Kaiser, Jozef

    2016-04-01

    A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.

  15. Optimization of liquid jet system for laser-induced breakdown spectroscopy analysis

    Science.gov (United States)

    Skočovská, Katarína; Novotný, Jan; Prochazka, David; Pořízka, Pavel; Novotný, Karel; Kaiser, Jozef

    2016-04-01

    A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.

  16. OPTIMIZED DETERMINATION OF TRACE JET FUEL VOLATILE ORGANIC COMPOUNDS IN HUMAN BLOOD USING IN-FIELD LIQUID-LIQUID EXTRACTION WITH SUBSEQUENT LABORATORY GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS AND ON-COLUMN LARGE VOLUME INJECTION

    Science.gov (United States)

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing te...

  17. Purification of four strains of endophytic fungi from Astragalus and their optimized liquid fermentations

    Institute of Scientific and Technical Information of China (English)

    Wei Ma; Xiubo Liu; Jiao Jiao; Leiming Zhang; Weichao Ren; Ling Ma; Xiangjun Kong; Ning Zhang; Xiwu Zhang

    2014-01-01

    This study was designed to isolate endophytic fungi from A. mongholicus (growing in northeast China) to determine whether they can produce bioactive metabolites. Four strains of endophytic fungi (strains 16, 17, 23 and 75) were successfully isolated from A. mongholicus using the surface disinfection method. According to ITS-rDNA sequences analysis, strains 16 and 75 were identified as Fusarium oxysporum, and strains 17 and 23 were identified as Bionectria ochroleuca. We applied the Box-Behnken design (BBD) to optimize the liquid fermentation conditions and obtain the maximum cell dry weight (CDW) yield. Opti-mal parameters were obtained under the following experimental condi-tions:temperature of 28°C, potato dextrose agar (PDA) liquid medium of 80 mL and rotation speed of 150 rpm. The four isolated endophytic fungi did not produce astragalosides I-IV, flavonoids or polysaccharides. Iso-lation of additional species of endophytic fungi from A. mongholicus and determination of their capacity to produce biologically active substances are subjects in need of further research.

  18. Optimizing the radiosensitive liquid-core microcapsules for the targeting of chemotherapeutic agents

    Energy Technology Data Exchange (ETDEWEB)

    Harada, S. [Department of Radiology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505 (Japan)]. E-mail: sharada@iwate-med.ac.jp; Ehara, S. [Department of Radiology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505 (Japan); Ishii, K. [Department of Quantum Science and Energy Engineering, Tohoku University, Sendai, Miyagi (Japan); Yamazaki, H. [Department of Quantum Science and Energy Engineering, Tohoku University, Sendai, Miyagi (Japan); Matsuyama, S. [Department of Quantum Science and Energy Engineering, Tohoku University, Sendai, Miyagi (Japan); Kamiya, T. [Takasaki Institute of the Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan); Sakai, T. [Takasaki Institute of the Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan); Arakawa, K. [Takasaki Institute of the Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan); Sato, T. [Takasaki Institute of the Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan); Oikawa, S. [Takasaki Institute of the Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Takasaki, Gunma (Japan)

    2007-07-15

    Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl{sub 2} solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy {sup 60}Co {gamma}-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 {+-} 3.3 {mu}m, and that of the liquid core was 10.2 {+-} 4.3 {mu}m. The maximum radiation-induced content release was observed with liquid-core microcapsules containing 0.1% hyaluronic acid and 0.2% alginate. Our liquid-core microcapsules suggest a new potential use for radiation: the targeted delivery of the chemotherapeutic agents or radiosensitizers. This offers the prospect of increased combined effectiveness of radiation with chemotherapy or radiosensitization and decreased adverse side effects.

  19. Cubic liquid crystalline nanoparticles: optimization and evaluation for ocular delivery of tropicamide.

    Science.gov (United States)

    Verma, Purnima; Ahuja, Munish

    2016-10-01

    The purpose of this study was to investigate the potential of cubic liquid crystalline nanoparticles for ocular delivery of tropicamide. Ultrasound-assisted fragmentation of cubic liquid crystalline bulk phases resulted in cubic liquid crystalline nanoparticles employing Pluronic F127 as dispersant. The effects of process variables such as sonication time, sonication amplitude, sonication depth, and pre-mixing time on particle size and polydispersity index was investigated using central composite design. The morphology of tropicamide-loaded nanoparticles was found to be nearly cubical in shape by transmission electron microscopy observation. Further, small angle X-ray scattering experiment confirmed the presence of D and P phase cubic structures in coexistence. The optimized tropicamide-loaded cubic nanoparticles showed in vitro corneal permeation of tropicamide across isolated porcine cornea comparable to its commercial preparation, Tropicacyl®. Ocular tolerance was evaluated by Hen's egg-chorioallantoic membrane test and histological studies. The results of in vivo mydriatic response study demonstrated a remarkably higher area under mydriatic response curve (AUC0→1440 min) values of cubic nanoparticles over Tropicacyl® indicating better therapeutic value of cubic nanoparticles. Furthermore, tropicamide-loaded cubic nanoparticles exhibited prolonged mydriatic effect on rabbits as compared to commercial conventional aqueous ophthalmic solution.

  20. Optimizing the radiosensitive liquid-core microcapsules for the targeting of chemotherapeutic agents

    Science.gov (United States)

    Harada, S.; Ehara, S.; Ishii, K.; Yamazaki, H.; Matsuyama, S.; Kamiya, T.; Sakai, T.; Arakawa, K.; Sato, T.; Oikawa, S.

    2007-07-01

    Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl 2 solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy 60Co γ-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 ± 3.3 μm, and that of the liquid core was 10.2 ± 4.3 μm. The maximum radiation-induced content release was observed with liquid-core microcapsules containing 0.1% hyaluronic acid and 0.2% alginate. Our liquid-core microcapsules suggest a new potential use for radiation: the targeted delivery of the chemotherapeutic agents or radiosensitizers. This offers the prospect of increased combined effectiveness of radiation with chemotherapy or radiosensitization and decreased adverse side effects.

  1. [Optimization of induction and culture conditions for hairy roots of Salvia miltiorrhiza].

    Science.gov (United States)

    Tan, Rong-Hui; Zhang, Jin-Jia; Zhao, Shu-Juan

    2014-08-01

    To establish induction and liquid culture system for hairy roots of Danshen (Salvia miltiorrhiza), Agrobacterium rhizogenes A4, LBA9402, 15834 as test bacterium were used to infect aseptic leaves of Danshen. The hairy roots were induced and positive transgenic hairy roots were selected with PCR using rolB and rolC as the target gene. Then hairy roots of S. miltiorrhiza were harvested and salvianolic acids were extracted with 70% methanol containing 1% formic acid. The content of salvianolic acid B (SalB) and rosmarinic acid (RA) were determined by HPLC. According to the above research results, the Danshen hairy roots induced by A. rhizogenes LBA9402 were inoculated into the following group of culture media: MSOH, MS, B5, and 6,7-V liquid media. Then the same methods of extraction and determination for the content of Danshen hairy roots were adopted. Last, the hairy roots of S. miltiorrhiza induced by A. rhizogenes LBA9402 were inoculated into the MSOH liquid media with different pH values. The content of salvianolic acid were extracted with 70% methanol containing 1% formic acid and determined by HPLC. As a result, three kinds of A. rhizogenes A4, LBA9402, 15834 could induce hairy roots and Ri plasmids were integrated into the genome of S. miltiorrhiza by PCR. Danshen hairy roots induced by A. rhizogenes LBA9402 and A4 produced much more salvianolic acid, which were (3.27 ± 0.37)% [including (1.04 ±0.36)% of RA and (2.22 ± 0.29)% of SalB] and (3.17 ± 0.20)% [including (0.92 ± 0.31)% of RA and (2.25 ± 0.26)% of SalB], respectively. Hairy roots induced by A. rhizogenes LBA9402 when they were cultured in MSOH liquid media produced much more salvianolic acid, which was (4.56 ± 0.36)%, including (1.12 ± 0.26)% of RA and (3.44 ± 0.23)% of SalB. Hairy roots induced by A. rhizogenes LBA9402 produced the most salvianolic acid when they were cultured in MSOH liquid media with the pH value 4.81, which was 4.85%, including 1.16% of RA and 3.69% of SalB. So Danshen

  2. Microfluidic Protocol for pre-implantation culture of single mammalian embryos: towards and optimal culture protocol

    NARCIS (Netherlands)

    Esteves, Telma C.; Rossem, van Fleur; Boiani, Michele; Berg, van den Albert; Le Gac, Séverine

    2011-01-01

    Microfluidics holds great potential for the field of assisted reproduction techniques (ART), to provide integrated platforms for combined embryo culture and characterization. The development of mouse embryos is not impaired in a microfluidic format: it proceeds faster during the pre-implantation per

  3. Magneto-responsive liquid crystalline elastomer nanocomposites as potential candidates for dynamic cell culture substrates.

    Science.gov (United States)

    Herrera-Posada, Stephany; Mora-Navarro, Camilo; Ortiz-Bermudez, Patricia; Torres-Lugo, Madeline; McElhinny, Kyle M; Evans, Paul G; Calcagno, Barbara O; Acevedo, Aldo

    2016-08-01

    Recently, liquid crystalline elastomers (LCEs) have been proposed as active substrates for cell culture due to their potential to attach and orient cells, and impose dynamic mechanical signals through the application of external stimuli. In this report, the preparation of anisotropic and oriented nematic magnetic-sensitized LCEs with iron oxide nanoparticles, and the evaluation of the effect of particle addition at low concentrations on the resultant structural, thermal, thermo-mechanical, and mechanical properties is presented. Phase transformations produced by heating in alternating magnetic fields were investigated in LCEs in contact with air, water, and a common liquid cell culture medium was also evaluated. The inclusion of nanoparticles into the elastomers displaced the nematic-to-isotropic phase transition, without affecting the nematic structure as evidenced by similar values of the order parameter, while reducing the maximum thermomechanical deformations. Remote and reversible deformations of the magnetic LCEs were achieved through the application of alternating magnetic fields, which induces the nematic-isotropic phase transition through nanoparticle heat generation. Formulation parameters can be modified to allow for remote actuation at values closer to the human physiological temperature range and within the range of deformations that can affect the cellular behavior of fibroblasts. Finally, a collagen surface treatment was performed to improve compatibility with NIH-3T3 fibroblast cultures, which enabled the attachment and proliferation of fibroblasts on substrates with and without magnetic particles under quiescent conditions. The LCEs developed in this work, which are able to deform and experience stress changes by remote contact-less magnetic stimulation, may allow for further studies on the effect of substrate morphology changes and dynamic mechanical properties during in vitro cell culture.

  4. CULTURAL AND LEGAL FACTORS OF OPTIMIZATION OF THE IDEOLOGY OF STATE-BUILDING IN UKRAINE

    Directory of Open Access Journals (Sweden)

    O. V. Krasnokutskyi

    2014-12-01

    Full Text Available The Purpose is to investigate the legal cultural phenomenon in the riches of the contours of its essence, raising the level of this phenomenon as part of the system of determinants of the optimization of ideology of state-building in modern Ukraine. Methodology. The study is based on the principles of materialist dialectics and the principles of historicism, social determinism, complexity. The scientific novelty. The cultural and legal factors of optimization of the ideology of state-building are conceptually considered for the first time in modern Ukraine; three methodological points that should be targeted in the definition of «legal culture» are outlined; the definition of legal culture is improved; a working template program of improvement and increase of the level of legal culture in contemporary Ukrainian society is developed; four key conceptual areas of the program are outlined. Conclusions. Legal culture can be defined as a separate category to mark the legal system which was historically formed and the institutions of a state-organized society that are correlated with it, and also the legal knowledge and motives, forms, techniques and methods of legal activities, values, estimates with the necessity inherent to every people, class, nation, community groups, to the individual person at a certain stage of their development. Rise of the level of legal awareness is one of the leading systematic factors, cultural and code keys to optimizing the development of state-building ideology in the conditions of today's Ukraine. The program for the improvement and enhancement of legal culture in contemporary Ukrainian society is composed of four major conceptual areas: the growth of basic legal literacy; the rise of their legal awareness; the increase of theoretical justification of the existing legal reality, the prospects for its future development, the increase of the efficiency of the legal theory; progressive formation of legal ideology.

  5. Optimization of Copper Removal from Aqueous Solutions Using Emulsion Liquid Membranes with Benzoylacetone as a Carrier

    Directory of Open Access Journals (Sweden)

    Loreto León

    2017-01-01

    Full Text Available The presence of heavy metals in aqueous solutions above certain limits represents a serious threat to the environment due to their toxicity and non-degradability. Thus, the removal of these metals from contaminated waters has received increasing attention during recent decades. This paper describes the removal of Cu(II from aqueous solutions by emulsion liquid membranes, through a carrier-facilitated counter-transport mechanism, using benzoylacetone as the carrier and HCl as the stripping agent (protons as counter-ions. To optimize the Cu(II removal process, the effect of the following operating parameters on the on the stability of the emulsion liquid membrane and on the Cu(II removal efficiency was studied: feed pH, HCl concentration in the permeate phase, carrier and emulsifier concentration in the membrane phase, feed phase/emulsion phase and permeate phase/membrane phase volume ratios, emulsification time and speed in the primary emulsion preparation and stirring speed in the whole feed phase/emulsion phase system. Typical membrane transport parameters, such as flux and permeability, were also determined. Optimal Cu(II removal conditions were: 5.5 feed pH, 10 kg/m3 benzoylacetone concentration in the membrane phase, 18.250 kg/m3 HCl concentration in the permeate phase, 50 kg/m3 Span 80 concentration in the membrane phase, 200 rpm stirring rate, 5 min emulsification time, 2700 rpm emulsification rate, 2:1 feed:emulsion volume ratio and 1:1 permeate:membrane volume ratio. In these optimal conditions, 80.3% of Cu(II was removed in 15 min with an apparent initial flux and permeability of 0.3384 kg·m−3·min−1 and 0.3208 min−1, respectively.

  6. Solubilization of Rock Phosphate in Liquid Culture by Fungal Isolates from Rhizosphere Soil

    Institute of Scientific and Technical Information of China (English)

    WANG Guang-Hua; ZHOU De-Rui; YANG Qian; JIN Jian; LIU Xiao-Bing

    2005-01-01

    Rock phosphate (RP) is a low efficiency P fertilizer that is directly applied to the soil and can be solubilized by phosphate-solubilizing microorganisms (PSMs) in fermentation or soil conditions. This study investigated dynamic solubilization of 2 concentrations of rock phosphate in a liquid culture with different dosages of glucose by two fungal isolates,Aspergillus niger P39 and Penicillium oxalicum P66, from soybean and wheat rhizosphere soil. Although during the 20day culture period A. niger P39 had a stronger ability to acidify the culture media than P. oxalicum P66, soluble P concentrations at glucose dosages of 30 and 50 gL-1 with RP of 15 g L-1 in the culture solution were much higher by P. oxalicum P66. The greater effectiveness of P. oxalicum P66 compared to A. niger P39 in the solubilization of RP was strongly associated with the production of organic acids. This study suggested that for RP solubilization the type rather than the concentration of PSM-produced organic acids was more important.

  7. Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

    Science.gov (United States)

    Müller, Loretta; Brighton, Luisa E.; Carson, Johnny L.; Fischer, William A.; Jaspers, Ilona

    2013-01-01

    In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. In vitro models of differentiated human nasal epithelial

  8. Culturing of human nasal epithelial cells at the air liquid interface.

    Science.gov (United States)

    Müller, Loretta; Brighton, Luisa E; Carson, Johnny L; Fischer, William A; Jaspers, Ilona

    2013-10-08

    In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. In vitro models of differentiated human nasal epithelial

  9. Optimization of culture conditions of Fusarium solani for the production of neoN-methylsansalvamide.

    Science.gov (United States)

    Lee, Hee-Seok; Phat, Chanvorleak; Nam, Woo-Seon; Lee, Chan

    2014-01-01

    The aim of this study was to optimize the culture conditions of Fusarium solani KCCM90040 on cereal grain for the production of neoN-methylsansalvamide, a novel low-molecular-weight cyclic pentadepsipeptide exhibiting cytotoxic and multidrug resistance reversal effects. From the analysis of variance results using response surface methodology, temperature, initial moisture content, and growth time were shown to be important parameters for the production of neoN-methylsansalvamide on cereal grain. A model was established in the present study to describe the relationship between environmental conditions and the production of neoN-methylsansalvamide on rice, the selected cereal grain. The optimal culture conditions were determined at 25.79 °C with the initial moisture content of 40.79%, and 16.19 days of growth time. This report will give important information concerning the optimization of environmental conditions using statistic methodology for the production of a new cyclic pentadepsipeptide from fungi.

  10. Antifatigue Activity of Liquid Cultured Tricholoma matsutake Mycelium Partially via Regulation of Antioxidant Pathway in Mouse

    Directory of Open Access Journals (Sweden)

    Quan Li

    2015-01-01

    Full Text Available Tricholoma matsutake has been popular as food and biopharmaceutical materials in Asian countries for its various pharmacological activities. The present study aims to analyze the antifatigue effects on enhancing exercise performance of Tricholoma matsutake fruit body (ABM and liquid cultured mycelia (TM in mouse model. Two-week Tricholoma matsutake treatment significantly enhances the exercise performance in weight-loaded swimming, rotating rod, and forced running test. In TM- and ABM-treated mice, some factors were observed at 60 min after swimming compared with nontreated mice, such as the increased levels of adenosine triphosphate (ATP, antioxidative enzymes, and glycogen and the reduced levels of malondialdehyde and reactive oxygen species in muscle, liver, and/or serum. Further data obtained from western blot show that CM and ABM have strongly enhanced the activation of 5′-AMP-activated protein kinase (AMPK, and the expressions of peroxisome proliferator have activated receptor γ coactivator-1α (PGC-1α and phosphofructokinase-1 (PFK-1 in liver. Our data suggest that both Tricholoma matsutake fruit body and liquid cultured mycelia possess antifatigue effects related to AMPK-linked antioxidative pathway. The information uncovered in our study may serve as a valuable resource for further identification and provide experimental evidence for clinical trials of Tricholoma matsutake as an effective agent against fatigue related diseases.

  11. Optimization of a Brayton cryocooler for ZBO liquid hydrogen storage in space

    Science.gov (United States)

    Deserranno, D.; Zagarola, M.; Li, X.; Mustafi, S.

    2014-11-01

    NASA is evaluating and developing technology for long-term storage of cryogenic propellant in space. A key technology is a cryogenic refrigerator which intercepts heat loads to the storage tank, resulting in a reduced- or zero-boil-off condition. Turbo-Brayton cryocoolers are particularly well suited for cryogen storage applications because the technology scales well to high capacities and low temperatures. In addition, the continuous-flow nature of the cycle allows direct cooling of the cryogen storage tank without mass and power penalties associated with a cryogenic heat transport system. To quantify the benefits and mature the cryocooler technology, Creare Inc. performed a design study and technology demonstration effort for NASA on a 20 W, 20 K cryocooler for liquid hydrogen storage. During the design study, we optimized these key components: three centrifugal compressors, a modular high-capacity plate-fin recuperator, and a single-stage turboalternator. The optimization of the compressors and turboalternator were supported by component testing. The optimized cryocooler has an overall flight mass of 88 kg and a specific power of 61 W/W. The coefficient of performance of the cryocooler is 23% of the Carnot cycle. This is significantly better performance than any 20 K space cryocooler existing or under development.

  12. Organizational transformation: a model for joint optimization of culture change and evidence-based design.

    Science.gov (United States)

    Hamilton, D Kirk; Orr, Robin Diane; Raboin, W Ellen

    2008-01-01

    Healthcare organizations face continuous and accelerating external change and thus must be prepared to manage their own change initiatives proactively. Given that many believe that the U.S. healthcare system is broken and most healthcare organizations are dealing with pervasive problems, some organizations may choose to seek transformational change to achieve the six aims identified by the Institute of Medicine: healthcare that is safe, effective, patient-centered, timely, efficient, and equitable. Transformational change will almost certainly involve organizational culture. Culture change may be most effective when linked to other organizational change initiatives such as organizational strategy, structure, policies, procedures, and recruiting. Significant organizational change often requires accompanying facility change. There is an interdependent relationship between facility design and organizational culture. They affect each other and both impact organizational performance. Sociotechnical theory promotes joint optimization of the social (culture) and technical (facilities) aspects of an organization to achieve sustained positive change. To achieve organizational transformation and to sustain positive change, organizations must be prepared to adopt collaborative efforts in culture change and facility design. The authors propose a model for accomplishing joint optimization of culture change and evidence-based facility design.

  13. Magneto-responsive liquid crystalline elastomer nanocomposites as potential candidates for dynamic cell culture substrates

    Energy Technology Data Exchange (ETDEWEB)

    Herrera-Posada, Stephany; Mora-Navarro, Camilo; Ortiz-Bermudez, Patricia; Torres-Lugo, Madeline [Department of Chemical Engineering, Call Box 9000, University of Puerto Rico, Mayagüez PR 00681 (Puerto Rico); McElhinny, Kyle M.; Evans, Paul G. [Department of Materials Science and Engineering, 1509 University Avenue, University of Wisconsin-Madison, WI 53706 (United States); Calcagno, Barbara O. [Department of General Engineering, Call Box 9000, University of Puerto Rico, Mayagüez PR 00681 (Puerto Rico); Acevedo, Aldo, E-mail: aldo.acevedo@upr.edu [Department of Chemical Engineering, Call Box 9000, University of Puerto Rico, Mayagüez PR 00681 (Puerto Rico)

    2016-08-01

    Recently, liquid crystalline elastomers (LCEs) have been proposed as active substrates for cell culture due to their potential to attach and orient cells, and impose dynamic mechanical signals through the application of external stimuli. In this report, the preparation of anisotropic and oriented nematic magnetic-sensitized LCEs with iron oxide nanoparticles, and the evaluation of the effect of particle addition at low concentrations on the resultant structural, thermal, thermo-mechanical, and mechanical properties is presented. Phase transformations produced by heating in alternating magnetic fields were investigated in LCEs in contact with air, water, and a common liquid cell culture medium was also evaluated. The inclusion of nanoparticles into the elastomers displaced the nematic-to-isotropic phase transition, without affecting the nematic structure as evidenced by similar values of the order parameter, while reducing the maximum thermomechanical deformations. Remote and reversible deformations of the magnetic LCEs were achieved through the application of alternating magnetic fields, which induces the nematic–isotropic phase transition through nanoparticle heat generation. Formulation parameters can be modified to allow for remote actuation at values closer to the human physiological temperature range and within the range of deformations that can affect the cellular behavior of fibroblasts. Finally, a collagen surface treatment was performed to improve compatibility with NIH-3T3 fibroblast cultures, which enabled the attachment and proliferation of fibroblasts on substrates with and without magnetic particles under quiescent conditions. The LCEs developed in this work, which are able to deform and experience stress changes by remote contact-less magnetic stimulation, may allow for further studies on the effect of substrate morphology changes and dynamic mechanical properties during in vitro cell culture. - Highlights: • Magnetic LCE nanocomposites were

  14. Optimization and robustness analysis of hybridoma cell fed-batch cultures using the overflow metabolism model.

    Science.gov (United States)

    Amribt, Z; Dewasme, L; Vande Wouwer, A; Bogaerts, Ph

    2014-08-01

    The maximization of biomass productivity in fed-batch cultures of hybridoma cells is analyzed based on the overflow metabolism model. Due to overflow metabolism, often attributed to limited oxygen capacity, lactate and ammonia are formed when the substrate concentrations (glucose and glutamine) are above a critical value, which results in a decrease in biomass productivity. Optimal feeding rate, on the one hand, for a single feed stream containing both glucose and glutamine and, on the other hand, for two separate feed streams of glucose and glutamine are determined using a Nelder-Mead simplex optimization algorithm. The optimal multi exponential feed rate trajectory improves the biomass productivity by 10 % as compared to the optimal single exponential feed rate. Moreover, this result is validated by the one obtained with the analytical approach in which glucose and glutamine are fed to the culture so as to control the hybridoma cells at the critical metabolic state, which allows maximizing the biomass productivity. The robustness analysis of optimal feeding profiles obtained with different optimization strategies is considered, first, with respect to parameter uncertainties and, finally, to model structure errors.

  15. Approaches to Optimizing Animal Cell Culture Process: Substrate Metabolism Regulation and Protein Expression Improvement

    Science.gov (United States)

    Zhang, Yuanxing

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  16. Approaches to optimizing animal cell culture process: substrate metabolism regulation and protein expression improvement.

    Science.gov (United States)

    Zhang, Yuanxing

    2009-01-01

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  17. Selective breeding for desiccation tolerance in liquid culture provides genetically stable inbred lines of the entomopathogenic nematode Heterorhabditis bacteriophora.

    Science.gov (United States)

    Anbesse, Samuel; Sumaya, Nanette Hope; Dörfler, Anna Verena; Strauch, Olaf; Ehlers, Ralf-Udo

    2013-01-01

    The entomopathogenic nematode (EPN) Heterorhabditis bacteriophora is used in biological plant protection to control pest insects. In the past, several attempts targeted at an enhancement of the desiccation tolerance of EPN by genetic selection in order to improve their storage stability. The subsequent loss of improved beneficial traits after release of selection pressure has often been reported. In order to stabilize progress of selective breeding, selection during liquid culturing was tested against propagation in host insects. After release of the selection pressure, the tolerance was monitored over additional reproductive cycles in vivo and in vitro to compare the stability of the trait. Furthermore, it was tested whether the virulence of the selected strains would be impaired. Exposure to desiccation stress prior to propagation, in vivo or in vitro, both resulted in increasing desiccation tolerance. When selection pressure was released, the gained tolerance was lost again during in vivo production, whereas the tolerance was maintained at a high level when EPNs were cultured in liquid culture. In Heterorhabditis sp., liquid culture conditions produce highly homozygous, genetically stable inbred lines. The investigation provides easily applicable methods to improve and stabilize beneficial traits of heterorhabditid EPNs through selective breeding in liquid culture. Compared to nematodes from in vivo propagation, production in liquid media yielded EPN of higher virulence.

  18. Toxicity of ionic liquids: eco(cyto)activity as complicated, but unavoidable parameter for task-specific optimization.

    Science.gov (United States)

    Egorova, Ksenia S; Ananikov, Valentine P

    2014-02-01

    Rapid progress in the field of ionic liquids in recent decades led to the development of many outstanding energy-conversion processes, catalytic systems, synthetic procedures, and important practical applications. Task-specific optimization emerged as a sharpening stone for the fine-tuning of structure of ionic liquids, which resulted in unprecedented efficiency at the molecular level. Ionic-liquid systems showed promising opportunities in the development of green and sustainable technologies; however, the chemical nature of ionic liquids is not intrinsically green. Many ionic liquids were found to be toxic or even highly toxic towards cells and living organisms. In this Review, we show that biological activity and cytotoxicity of ionic liquids dramatically depend on the nature of a biological system. An ionic liquid may be not toxic for particular cells or organisms, but may demonstrate high toxicity towards another target present in the environment. Thus, a careful selection of biological activity data is a must for the correct assessment of chemical technologies involving ionic liquids. In addition to the direct biological activity (immediate response), several indirect effects and aftereffects are of primary importance. The following principal factors were revealed to modulate toxicity of ionic liquids: i) length of an alkyl chain in the cation; ii) degree of functionalization in the side chain of the cation; iii) anion nature; iv) cation nature; and v) mutual influence of anion and cation.

  19. Optimization method for the study of the properties of Al-Sn binary liquid alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, G.K. [University Department of Physics, T.M. Bhagalpur University, Bhagalpur (India); Pulchowk Campus, IOE, Tribhuvan University, Lalitpur (Nepal); Singh, B.K. [University Department of Physics, T.M. Bhagalpur University, Bhagalpur (India); Jha, I.S. [M.M.A.M. Campus, Tribhuvan University, Biratnagar (Nepal); Singh, B.P. [University Department of Physics, T.M. Bhagalpur University, Bhagalpur (India); Adhikari, D., E-mail: adksbdev@yahoo.com [M.M.A.M. Campus, Tribhuvan University, Biratnagar (Nepal)

    2017-06-01

    The best fit value of order energy parameter (W) has been estimated over the entire range of concentration in Al-Sn binary liquid alloy at a specified temperature to determine the thermodynamic properties and concentration fluctuations, obtained by a theoretical formalism in which the combined effect of size ratio, entropic and enthalpic effect is considered. The values of W at different temperatures have been determined by finding the temperature derivative of W which are then used for the optimization procedure in order to determine the corresponding values of excess free energy of mixing, partial excess free energy of mixing and activity of the components involved in the alloy. These parameters have been used to calculate the concentration fluctuations in long wavelength limit {S_c_c(0)} at different temperatures over the entire range of concentration which predict the stability of the alloy at different temperatures.

  20. Towards an optimal model for a bistable nematic liquid crystal display device

    KAUST Repository

    Cummings, L. J.

    2013-03-13

    Bistable liquid crystal displays offer the potential for considerable power savings compared with conventional (monostable) LCDs. The existence of two stable field-free states that are optically distinct means that contrast can be maintained in a display without an externally applied electric field. An applied field is required only to switch the device from one state to the other, as needed. In this paper we examine a theoretical model of a possible bistable device, originally proposed by Cummings and Richardson (Euro J Appl Math 17:435-463 2006), and explore means by which it may be optimized, in terms of optical contrast, manufacturing considerations, switching field strength, and switching times. The compromises inherent in these conflicting design criteria are discussed. © 2013 Springer Science+Business Media Dordrecht.

  1. OPTICAL OPTIMIZATION FOR LIQUID CRYSTAL TEST BY LASER-CCD SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Chang Ying; Zhu Henian; Zhang Ziliang; Yang Changxi

    2005-01-01

    For the narrowband of liner charge-coupled device (CCD) receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula. Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal (LC) case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.

  2. Performance and Optimization for a Ground-Coupled Liquid Loop Heat Recovery Ventilation System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ya-su; Per FAHLEN; Torbj(o)rn LINDHOLM

    2007-01-01

    Ground-coupled heat pumps(GCHP) arecommonly used in residential heating system. To mitigatethe boreholes temperature dropping with operating time, anew exhaust-air recharging system is developed. The newrecharging system can be used in three operational modes.In this paper, a ground-coupled heat recovery ventilation(HRV) model is discussed. A thermal model is set up tofind the optimal brine flow rate and heat transfer allocationratio between exhaust and supply coils for maximum heatrecovery efficiency. Contrary to the conventional liquid-loopHRV systems, the brine temperature entering the exhaustcoil never goes blow zero(0℃), and hence defrosting isneedless in the ground-coupled HRV system. This can makethe ground-coupled HRV system over 20% more efficientthan a conventional HRV system at low outdoortemperatures.

  3. Effects of carbon and nitrogen sources, carbon-to-nitrogen ratio, and initial pH on the growth of nematophagous fungus Pochonia chlamydosporia in liquid culture.

    Science.gov (United States)

    Mo, Minghe; Xu, Chuankun; Zhang, Keqin

    2005-04-01

    The effects of carbon and nitrogen sources, carbon-to-nitrogen ratio (C:N) and initial pH value on the growth and sporulation of the nematophagous fungus Pochonia chlamydosporia in liquid culture were examined. Among the 21 carbon sources and 15 nitrogen compounds tested, the optimal carbon and nitrogen sources for mycelial growth were sweet potato and L: -tyrosine, and for sporulation were sweet potato and casein peptone. A C:N ratio of 10:1 at pH 3.7 gave the maximum yield of conidia and a C:N ratio of 40:1 at pH 6.8 gave the maximum biomass. The initial pH value had a significant effect on mycelial growth and conidial production, with the optimal ranges being 3.5-4.5 for sporulation and 5-6 for growth. Maximum conidial production was obtained at an initial pH of 4.0 and the maximum biomass at pH 6.0. The results also showed that the final pH after 7 days cultivation was always higher than the initial value. The variability in growth and sporulation of seven strains of P. chlamydosporia in liquid culture was also compared and discussed.

  4. Statistical approach for the culture conditions optimization of magnetotactic bacteria for magnetic cells production

    Institute of Scientific and Technical Information of China (English)

    Li Wenbing; Yu Longjiang; Zhou Pengpeng

    2006-01-01

    The culture of Magnetospirillum magneticum WM-1 depends on several control factors that have great effect on the magnetic cells concentration. Investigation into the optimal culture conditions needs a large number of experiments. So it is desirable to minimize the number of experiments and maximize the information gained from them. The orthogonal design of experiments and mathematical statistical method are considered as effective methods to optimize the culture condition of magnetotactic bacteria WM-1 for high magnetic cells concentration. The effects of the four factors, such as pH value of medium, oxygen concentration of gas phase in the serum bottle, C:C (mtartaric acid: msuccinic acid) ratio and NaNO3 concentration, are simultaneously investigated by only sixteen experiments through the orthogonal design L16(44) method. The optimal culture condition is obtained. At the optimal culture condition ( pH 7.0, an oxygen concentration 4.0%, C: C (mtartaric acid:msuccinic acid) ratio 1:2 and NaNO3 100 mg l-1), the magnetic cells concentration is promoted to 6.5×107 cells ml-1, approximately 8.3% higher than that under the initial conditions. The pH value of medium is a very important factor for magnetic cells concentration. It can be proved that the orthogonal design of experiment is of 90% confidence. Ferric iron uptake follows Michaelis-Menten kinetics with a Km of 2.5 μM and a Vmax of 0.83 min-1.

  5. Optimization of culture medium for the continuous cultivation of the microalga Haematococcus pluvialis.

    Science.gov (United States)

    Fábregas, J; Domínguez, A; Regueiro, M; Maseda, A; Otero, A

    2000-05-01

    The freshwater microalga Haematococcus pluvialis is one of the best microbial sources of the carotenoid astaxanthin, but this microalga shows low growth rates and low final cell densities when cultured with traditional media. A single-variable optimization strategy was applied to 18 components of the culture media in order to maximize the productivity of vegetative cells of H. pluvialis in semicontinuous culture. The steady-state cell density obtained with the optimized culture medium at a daily volume exchange of 20% was 3.77 x 10(5) cells ml(-1), three times higher than the cell density obtained with Bold basal medium and with the initial formulation. The formulation of the optimal Haematococcus medium (OHM) is (in g l(-1)) KNO3 0.41, Na2HPO4 0.03, MgSO4 x 7H2O 0.246, CaCl2 x 2H2O 0.11, (in mg l(-1)) Fe(III)citrate x H2O 2.62, CoCl2 x 6H2O 0.011, CuSO4 x 5H2O 0.012, Cr2O3 0.075, MnCl2 x 4H2O 0.98, Na2MoO4 x 2H2O 0.12, SeO2 0.005 and (in microg l(-1)]) biotin 25, thiamine 17.5 and B12 15. Vanadium, iodine, boron and zinc were demonstrated to be non-essential for the growth of H. pluvialis. Higher steady-state cell densities were obtained by a three-fold increase of all nutrient concentrations but a high nitrate concentration remained in the culture medium under such conditions. The high cell productivities obtained with the new optimized medium can serve as a basis for the development of a two-stage technology for the production of astaxanthin from H. pluvialis.

  6. Optimized ion acceleration using high repetition rate, variable thickness liquid crystal targets

    Science.gov (United States)

    Poole, Patrick; Willis, Christopher; Cochran, Ginevra; Andereck, C. David; Schumacher, Douglass

    2015-11-01

    Laser-based ion acceleration is a widely studied plasma physics topic for its applications to secondary radiation sources, advanced imaging, and cancer therapy. Recent work has centered on investigating new acceleration mechanisms that promise improved ion energy and spectrum. While the physics of these mechanisms is not yet fully understood, it has been observed to dominate for certain ranges of target thickness, where the optimum thickness depends on laser conditions including energy, pulse width, and contrast. The study of these phenomena is uniquely facilitated by the use of variable-thickness liquid crystal films, first introduced in P. L. Poole et al. PoP21, 063109 (2014). Control of the formation parameters of these freely suspended films such as volume, temperature, and draw speed allows on-demand thickness variability between 10 nanometers and several 10s of microns, fully encompassing the currently studied thickness regimes with a single target material. The low vapor pressure of liquid crystal enables in-situ film formation and unlimited vacuum use of these targets. Details on the selection and optimization of ion acceleration mechanism with target thickness will be presented, including recent experiments on the Scarlet laser facility and others. This work was performed with support from the DARPA PULSE program through a grant from AMRDEC and by the NNSA under contract DE-NA0001976.

  7. [Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars].

    Science.gov (United States)

    Liu, Jianjun; Peng, Hehuan; Zhao, Xiangjun; Cheng, Cheng; Chen, Feng; Shao, Qianjun

    2013-03-01

    China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.

  8. Parametric study for the optimization of ionic liquid pretreatment of corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Papa, Gabriella [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Feldman, Taya [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sale, Kenneth L. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Adani, Fabrizio [Univ. degli Studi di Milano (Italy); Singh, Seema [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Simmons, Blake A. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-05-30

    A parametric study of the efficacy of the ionic liquid (IL) pretreatment (PT) of corn stover (CS) using 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc] ) and cholinium lysinate ([Ch][Lys] ) was conducted. The impact of 50% and 15% biomass loading for milled and non-milled CS on IL-PT was evaluated, as well the impact of 20 and 5 mg enzyme/g glucan on saccharification efficiency. The glucose and xylose released were generated from 32 conditions – 2 ionic liquids (ILs), 2 temperatures, 2 particle sizes (S), 2 solid loadings, and 2 enzyme loadings. Statistical analysis indicates that sugar yields were correlated with lignin and xylan removal and depends on the factors, where S did not explain variation in sugar yields. Both ILs were effective in pretreating large particle sized CS, without compromising sugar yields. The knowledge from material and energy balances is an essential step in directing optimization of sugar recovery at desirable process conditions.

  9. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca.

    Science.gov (United States)

    West, Jenna; Mitchell, Alexandra; Pung, Oscar J

    2014-01-01

    In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco's Modified Eagle medium/F-12 (DME/F-12) than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae.

  10. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca

    Directory of Open Access Journals (Sweden)

    Jenna West

    2014-01-01

    Full Text Available In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco’s Modified Eagle medium/F-12 (DME/F-12 than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae.

  11. On the model-based optimization of secreting mammalian cell (GS-NS0) cultures.

    Science.gov (United States)

    Kiparissides, A; Pistikopoulos, E N; Mantalaris, A

    2015-03-01

    The global bio-manufacturing industry requires improved process efficiency to satisfy the increasing demands for biochemicals, biofuels, and biologics. The use of model-based techniques can facilitate the reduction of unnecessary experimentation and reduce labor and operating costs by identifying the most informative experiments and providing strategies to optimize the bioprocess at hand. Herein, we investigate the potential of a research methodology that combines model development, parameter estimation, global sensitivity analysis, and selection of optimal feeding policies via dynamic optimization methods to improve the efficiency of an industrially relevant bioprocess. Data from a set of batch experiments was used to estimate values for the parameters of an unstructured model describing monoclonal antibody (mAb) production in GS-NS0 cell cultures. Global Sensitivity Analysis (GSA) highlighted parameters with a strong effect on the model output and data from a fed-batch experiment were used to refine their estimated values. Model-based optimization was used to identify a feeding regime that maximized final mAb titer. An independent fed-batch experiment was conducted to validate both the results of the optimization and the predictive capabilities of the developed model. The successful integration of wet-lab experimentation and mathematical model development, analysis, and optimization represents a unique, novel, and interdisciplinary approach that addresses the complicated research and industrial problem of model-based optimization of cell based processes.

  12. Optimal Control for Multistage Nonlinear Dynamic System of Microbial Bioconversion in Batch Culture

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2011-01-01

    Full Text Available In batch culture of glycerol biodissimilation to 1,3-propanediol (1,3-PD, the aim of adding glycerol is to obtain as much 1,3-PD as possible. Taking the yield intensity of 1,3-PD as the performance index and the initial concentration of biomass, glycerol, and terminal time as the control vector, we propose an optimal control model subject to a multistage nonlinear dynamical system and constraints of continuous state. A computational approach is constructed to seek the solution of the above model. Firstly, we transform the optimal control problem into the one with fixed terminal time. Secondly, we transcribe the optimal control model into an unconstrained one based on the penalty functions and an extension of the state space. Finally, by approximating the control function with simple functions, we transform the unconstrained optimal control problem into a sequence of nonlinear programming problems, which can be solved using gradient-based optimization techniques. The convergence analysis and optimality function of the algorithm are also investigated. Numerical results show that, by employing the optimal control, the concentration of 1,3-PD at the terminal time can be increased, compared with the previous results.

  13. Habitus and Flow in Primary School Musical Practice: Relations between Family Musical Cultural Capital, Optimal Experience and Music Participation

    Science.gov (United States)

    Valenzuela, Rafael; Codina, Nuria

    2014-01-01

    Based on Bourdieu's idea that cultural capital is strongly related to family context, we describe the relations between family musical cultural capital and optimal experience during compulsory primary school musical practice. We analyse whether children from families with higher levels of musical cultural capital, and specifically with regard to…

  14. Optimization of Differential Display of Prokaryotic mRNA: Application to Pure Culture and Soil Microcosms

    OpenAIRE

    Fleming, James T.; Yao, Wen-Hsiang; Sayler, Gary S.

    1998-01-01

    The differential display (DD) technique, which is widely used almost exclusively for eukaryotic gene discovery, was optimized to detect differential mRNA transcription from both pure-culture and soil-derived bacterial RNA. A model system which included toluene induction of todC1 in Pseudomonas putida F1 was used to optimize the procedure. At 24-h tod induction was determined to be approximately 8 × 107 transcripts/μg or 0.08% of the total mRNA. The primer concentration, primer length, anneali...

  15. Evaluation of BioFM liquid medium for culture of cerebrospinal fluid in tuberculous meningitis to identify Mycobacterium tuberculosis.

    Science.gov (United States)

    Kashyap, R S; Ramteke, S S; Gaherwar, H M; Deshpande, P S; Purohit, H J; Taori, G M; Daginawala, H

    2010-01-01

    The present study was designed to evaluate the sensitivity and specificity of liquid culture medium (BioFM broth) for the diagnosis of tuberculous meningitis (TBM) in cerebrospinal fluid (CSF). CSF samples from 200 patients (TBM group = 150 and non-TBM group = 50) were tested for culture of Mycobacterium tuberculosis in BioFM liquid culture medium. Out of 150 TBM cases, 120 were found to be culture positive, indicating a sensitivity of 80% in BioFM broth within 2-3 weeks of inoculation. Positive cultures were also observed for CSF from 32 (64%) out of 50 non-TBM patients in BioFM liquid culture medium within 4 days of sample inoculation. Therefore, according to our study, BioFM broth system yielded 80% sensitivity [95% confidence interval (CI): 67-93%] and 36% specificity (95% CI: 57-98%) for TBM diagnosis. Our results indicate that although BioFM broth allows the detection of positive cultures within a shorter time, it has a high potential for contamination or for the coexistence of M. tuberculosis and non-tuberculous meningitis (NTM). This coexistence may go undetected or potentially lead to erroneous reporting of results.

  16. Evaluation of BioFM liquid medium for culture of cerebrospinal fluid in tuberculous meningitis to identify Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Kashyap R

    2010-01-01

    Full Text Available The present study was designed to evaluate the sensitivity and specificity of liquid culture medium (BioFM broth for the diagnosis of tuberculous meningitis (TBM in cerebrospinal fluid (CSF. CSF samples from 200 patients (TBM group = 150 and non-TBM group = 50 were tested for culture of Mycobacterium tuberculosis in BioFM liquid culture medium. Out of 150 TBM cases, 120 were found to be culture positive, indicating a sensitivity of 80% in BioFM broth within 2-3 weeks of inoculation. Positive cultures were also observed for CSF from 32 (64% out of 50 non-TBM patients in BioFM liquid culture medium within 4 days of sample inoculation. Therefore, according to our study, BioFM broth system yielded 80% sensitivity [95% confidence interval (CI: 67-93%] and 36% specificity (95% CI: 57-98% for TBM diagnosis. Our results indicate that although BioFM broth allows the detection of positive cultures within a shorter time, it has a high potential for contamination or for the coexistence of M. tuberculosis and non-tuberculous meningitis (NTM. This coexistence may go undetected or potentially lead to erroneous reporting of results.

  17. Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology.

    Science.gov (United States)

    Xue, Juan Qin; Liu, Ni Na; Li, Guo Ping; Dang, Long Tao

    To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.

  18. Utility of MPT64 antigen test for differentiating mycobacteria: Can correlation with liquid culture smear morphology add further value?

    Directory of Open Access Journals (Sweden)

    Vidya Nerurkar

    2016-01-01

    Full Text Available Context: Clinical presentation of Mycobacterium tuberculosis complex (MTBC and non-tuberculous mycobacteria (NTM infections may or may not be the same, but the treatment is always different. Hence accurate differentiation between MTBC and NTM is of utmost importance. Aims: To assess in parallel, the utility of MPT64 antigen immunochromatography assay (MPT64 ICT and bacillary morphology on liquid culture smear, for rapid differentiation between MTBC and NTM in clinical isolates. Settings and Designs: Private sector reference laboratory, prospective. Subjects and Methods: Thousand and ninety-three mycobacterial isolates, recovered using Mycobacteria Growth Indicator Tube 960 liquid culture system (BD, USA, were subjected to MPT64 ICT (Standard Diagnostics Inc., Korea, para amino nitrobenzoicacid (PNB, niacin, and nitrate reduction tests. Smears prepared from culture vials were subjected to Ziehl-Neelsen staining and observed microscopically for typical patterns (chords, single cells, etc.,. PNB, nitrate and niacin tests served as the reference method for MTBC identification. Results: Thousand and fourteen and 79 isolates were identified as MTBC and NTM, respectively. MPT64 ICT correctly identified 955/1014 MTBC and all NTM isolates, yielding sensitivity and specificity of 94.2% and 100%, respectively. 936/1014 (92.3% MTBC isolates revealed characteristic serpentine chording on culture smear including 56/59 MPT64 ICT negative isolates. Sensitivity and specificity of liquid culture smear were 98.1% and 82.3%, respectively. Conclusion: Correlation of MPT64 ICT results with liquid culture smear was useful, especially in MPT64 ICT negative isolates, where the latter could help to determine need and/or type of additional confirmatory testing. Liquid culture smear, however, lacked specificity and cannot be used as a stand alone test.

  19. Optimization of professional preparation of future teacher of physical culture in informatively-educational space

    Directory of Open Access Journals (Sweden)

    Dragnev Y. V.

    2012-06-01

    Full Text Available It is marked that reformation of higher education is an objective necessity. It is marked that the educational system of Ukraine answers the new requirements of informative society not fully. It is certain that optimization of professional education of future teacher of physical culture must be characterized the choice of the most favourable variant of terms and teaching facilities. It is set that transitions within the limits of one informative space have an influence on professional development of future teacher during his studies. The followings terms of optimization of professional education of teacher are selected: system use of active and interactive methods; bringing in to the advanced study; the increase of role is informative of communication technologies in an educational process. The concordance of maintenance of curriculum of education of teachers of physical culture with the programs of education of the European countries and standardization is recommended them within the limits of Ukraine.

  20. [Automated methods of culture determination of M. tuberculosis in liquid media].

    Science.gov (United States)

    Irtuganova, O A; Smirnova, N S; Slogotskaia, L V; Moroz, A M; Litvinov, V I

    2001-01-01

    A hundred and seventy respiratory samples from patients with different forms of tuberculosis were used to test the efficiency of the automatic liquid culture systems BACTEC MGIT 960 and MB/BacT with inoculation into the standard dense media. All these media provided 47 M. tuberculous isolates, of them 41 (87.2%), 38 (80.9%), and 76.6% on the BACTER 960, MB/BacT, and dense media, respectively. The average time of detection of mycobacterial growth by means of automatic systems was much shorter and equal to 10.7 days on the BACTEC 960 and 18.7 days on the MB/BacT versus 33.2 days on the standard dense medium. In terms of their sensitivity and detection rate, the automatic systems were superior to the dense media widely used in laboratory practice.

  1. Optimal control of inspired perfluorocarbon temperature for induction of hypothermia by total liquid ventilation in juvenile lamb model.

    Science.gov (United States)

    Nadeau, Mathieu; Sage, Michael; Praud, Jean-Paul; Tissier, Renaud; Walti, Herve; Micheau, Philippe; Nadeau, Mathieu; Sage, Michael; Praud, Jean-Paul; Tissier, Renaud; Walti, Herve; Micheau, Philippe; Sage, Michael; Micheau, Philippe; Praud, Jean-Paul; Nadeau, Mathieu; Walti, Herve; Tissier, Renaud

    2016-08-01

    Mild hypothermia is well known for its therapeutic value in cardio- and neuroprotection. Many recent experimental studies have shown that the swiftness of the cooling offered by total liquid ventilation (TLV) holds great promise in achieving maximal therapeutic effect. TLV is an emerging ventilation technique in which the lungs are filled with breathable liquids, namely perfluorocarbons (PFCs). A liquid ventilator ensures subject ventilation by periodically renewing a volume of oxygenated, CO2-free and temperature-controlled breathable PFC. The substantial difference between breathing air and liquid is related to the fact that PFCs have over 500 times the volumetric thermal capacity of air 100% relative humidity. The PFC-filled lungs thus turn into an efficient heat exchanger with pulmonary circulation. The objective of the present study was to compute a posteriori the optimal inspired PFC temperature for ultrafast induction of mild hypothermia by TLV in a juvenile lamb experimentation using direct optimal control. The continuous time model and the discretized cycle-by-cycle model are presented. The control objectives of the direct optimal control are also presented and the results are compared with experimental data in order to validate the improved control performances. The computed direct optimal control showed that the inspired PFC temperature command can be improved to avoid temperature undershoots without altering the cooling performances.

  2. Progresses and challenges in optimization of human pluripotent stem cell culture.

    Science.gov (United States)

    Lin, Ge; Xu, Ren-He

    2010-09-01

    The pressing demand to elucidate the biology of human embryonic stem (ES) cells and to realize their therapeutic potential has greatly promoted the progresses in the optimization of the culture systems used for this highly promising cell type. These progresses include the characterization of exogenous regulators of pluripotency and differentiation, the development of animal-free, defined, and scalable culture systems, and some pioneering efforts to establish good manufactory practice facilities to derive and expand clinical-grade human ES cells and their derivatives. All of these advancements appear to be also applicable to the derivation and culture of human induced pluripotent stem cells, an ES cell-like cell type derived from somatic cells via reprogramming. This review attempts to summarize these progresses and discuss some of the remaining challenges.

  3. Modelling of Microalgae Culture Systems with Applications to Control and Optimization.

    Science.gov (United States)

    Bernard, Olivier; Mairet, Francis; Chachuat, Benoît

    2016-01-01

    Mathematical modeling is becoming ever more important to assess the potential, guide the design, and enable the efficient operation and control of industrial-scale microalgae culture systems (MCS). The development of overall, inherently multiphysics, models involves coupling separate submodels of (i) the intrinsic biological properties, including growth, decay, and biosynthesis as well as the effect of light and temperature on these processes, and (ii) the physical properties, such as the hydrodynamics, light attenuation, and temperature in the culture medium. When considering high-density microalgae culture, in particular, the coupling between biology and physics becomes critical. This chapter reviews existing models, with a particular focus on the Droop model, which is a precursor model, and it highlights the structure common to many microalgae growth models. It summarizes the main developments and difficulties towards multiphysics models of MCS as well as applications of these models for monitoring, control, and optimization purposes.

  4. Mutagenesis breeding of high echinocandin B producing strain and further titer improvement with culture medium optimization.

    Science.gov (United States)

    Zou, Shu-Ping; Zhong, Wei; Xia, Chao-Jie; Gu, Ya-Nan; Niu, Kun; Zheng, Yu-Guo; Shen, Yin-Chu

    2015-10-01

    A combination of microbial strain improvement and statistical optimization is investigated to maximize echinocandin B (ECB) production from Aspergillus nidulans ZJB-0817. A classical sequential mutagenesis was studied first by using physical (ultraviolet irradiation at 254 nm) and chemical mutagens (lithium chloride and sodium nitrite). Mutant strain ULN-59 exhibited 2.1-fold increase in ECB production to 1583.1 ± 40.9 mg/L when compared with the parent strain (750.8 ± 32.0 mg/L). This is the first report where mutagenesis is applied in Aspergillus to improve ECB production. Further, fractional factorial design and central composite design were adopted to optimize the culture medium for increasing ECB production by the mutant ULN-59. Results indicated that four culture media including peptone, K2HPO4, mannitol and L-ornithine had significant effects on ECB production. The optimized medium provided another 1.4-fold increase in final ECB concentration to 2285.6 ± 35.6 mg/L compared to the original medium. The results of this study indicated the combined application of a classical mutation and medium optimization can improve effectively ECB production from A. nidulans and could be a promising tool to improve other secondary metabolites production by fungal strains.

  5. PROPAGATION OF Portulaca oleracea L. IN LIQUID MEDIUM: IMPLICATIONS OF PLANT GROWTH REGULATORS IN CULTURE

    Directory of Open Access Journals (Sweden)

    Mahipal S. Shekhawat

    2015-02-01

    Full Text Available Portulaca oleracea L. is a medicinal plant, growing in warm and moist regions of north hemisphere of the world. A protocol for in vitro propagation using nodal shoot segments as explants has been outlined. The percent shoot response with shoot induction rate, 6.4 ± 0.7 shoots per explant, was achieved when cultured on agar-gelled Murashige and Skoog (MS medium containing 2.0 mg/L of BAP (6-benzylaminopurine. The cultures were amplified by passages on MS medium with 1.0 mg/L each BAP and kinetin (Kn. The best shoot amplification (37.5±0.9 shoots per vessel was achieved by subculturing of in vitro regenerated shoot clumps on liquid MS medium. Shoots regenerated in vitro by both the processes were rooted on ½ strength of MS medium + 2.0 mg/L of indole-3 butyric acid (IBA. Ninety six percent of the shoots rooted in vitro. The in vitro rooted plantlets were hardened under different regimes of temperature and humidity in the greenhouse. The hardened plantlets were transferred to mixture of soil and manure in polybags.

  6. Effect of light with different wavelengths on Nostoc flagelliforme cells in liquid culture.

    Science.gov (United States)

    Dai, Yu-Jie; Li, Jing; Wei, Shu-Mei; Chen, Nan; Xiao, Yu-Peng; Tan, Zhi-Lei; Jia, Shi-Ru; Yuan, Nan-Nan; Tan, Ning; Song, Yi-Jie

    2013-04-01

    The effects of lights with different wavelengths on the growth and the yield of extracellular polysaccharides of Nostoc flagelliforme cells were investigated in a liquid cultivation. N. flagelliforme cells were cultured for 16 days in 500 ml conical flasks containing BG11 culture medium under 27 micromol·m-2·s-1 of light intensity and 25 degrees C on a rotary shaker (140 rpm). The chlorophyll a, phycocyanin, allophycocyanin, and phycoerythrin contents in N. flagelliforme cells under the lights of different wavelengths were also measured. It was found that the cell biomass and the yield of polysaccharide changed with different wavelengths of light. The biomass and the yield of extracellular polysaccharides under the red or violet light were higher than those under other light colors. Chlorophyll a, phycocyanin, and allophycocyanin are the main pigments in N. flagelliforme cells. The results showed that N. flagelliforme, like other cyanobacteria, has the ability of adjusting the contents and relative ratio of its pigments with the light quality. As a conclusion, N. flagelliforme cells favor red and violet lights and perform the complementary chromatic adaptation ability to acclimate to the changes of the light quality in the environment.

  7. Vision Marker-Based In Situ Examination of Bacterial Growth in Liquid Culture Media

    Science.gov (United States)

    Kim, Kyukwang; Choi, Duckyu; Lim, Hwijoon; Kim, Hyeongkeun; Jeon, Jessie S.

    2016-01-01

    The detection of bacterial growth in liquid media is an essential process in determining antibiotic susceptibility or the level of bacterial presence for clinical or research purposes. We have developed a system, which enables simplified and automated detection using a camera and a striped pattern marker. The quantification of bacterial growth is possible as the bacterial growth in the culturing vessel blurs the marker image, which is placed on the back of the vessel, and the blurring results in a decrease in the high-frequency spectrum region of the marker image. The experiment results show that the FFT (fast Fourier transform)-based growth detection method is robust to the variations in the type of bacterial carrier and vessels ranging from the culture tubes to the microfluidic devices. Moreover, the automated incubator and image acquisition system are developed to be used as a comprehensive in situ detection system. We expect that this result can be applied in the automation of biological experiments, such as the Antibiotics Susceptibility Test or toxicity measurement. Furthermore, the simple framework of the proposed growth measurement method may be further utilized as an effective and convenient method for building point-of-care devices for developing countries. PMID:27999349

  8. Liquid semen storage in elephants (Elephas maximus and Loxodonta africana): species differences and storage optimization.

    Science.gov (United States)

    Kiso, Wendy K; Brown, Janine L; Siewerdt, Frank; Schmitt, Dennis L; Olson, Deborah; Crichton, Elizabeth G; Pukazhenthi, Budhan S

    2011-01-01

    Artificial insemination plays a key role in the genetic management of elephants in zoos. Because freshly extended semen is typically used for artificial insemination in elephants, it has become imperative to optimize conditions for liquid storage and semen transport. The objectives of this study were to examine the interactions between different extenders and storage temperatures on sperm total motility, progressive motility, and acrosomal integrity in Asian (Elephas maximus) and African (Loxodonta africana) elephants. Ejaculates were collected by rectal massage, diluted using a split-sample technique in 5 semen extenders: TL-Hepes (HEP), Modena (MOD), Biladyl (BIL), TEST refrigeration medium (TES), and INRA96 (INR), maintained at 35°C, 22°C, or 4°C. At 0, 4, 6, 12, and 24 hours, aliquots were removed and assessed for sperm total motility, progressive motility, and acrosomal integrity. After 24 hours of storage, African elephant spermatozoa exhibited greater longevity and higher values in sperm quality parameters compared with those of Asian elephants. In both species, semen storage at 35°C resulted in a sharp decline in all sperm quality parameters after 4 hours of storage, whereas storage at 22°C and 4°C facilitated sperm survival. In Asian elephants, MOD and HEP were most detrimental, whereas BIL, TES, and INR maintained motility up to 12 hours when spermatozoa were cooled to 22°Cor4°C. In African elephants, there were no differences among extenders. All media maintained good sperm quality parameters at 22°C or 4°C. However, although MOD, BIL, and INR were most effective at lower temperatures, HEP and TES maintained sperm motility at all storage temperatures. This study demonstrated sperm sensitivity to components of various semen extenders and storage temperatures and offers recommendations for semen extender choices for liquid semen storage for both Asian and African elephants.

  9. Optimal in vitro culture conditions for murine predominant immature CD8a+ dendritic cells

    Institute of Scientific and Technical Information of China (English)

    NA Ning; XU Lin; CAO Kai-yuan; LUO Yun; YUAN Guang-qing; XIANG Peng; HONG Liang-qing; LI Shu-nong

    2009-01-01

    Background The prospects of using immature CD8a+ dendritic cells (DC2) to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for inducing DC2 are still being explored. The present study was aimed to investigate the optimal in vitro conditions for preparing large numbers f predominant DC2 from murine bone marrow cells.Methods Three groups of bone marrow cells cultured under different conditions were examined, namely a cytokine-induced experimental group (cytokine group), a control group with a low concentration of granulocyte-macrophage colony stimulating factor (GM-CSF, low GM-CSF group) and a control group without ndogenous cytokines. The cytokine group was cultured with 5 ng/ml GM-CSF, 25 ng/ml Fit3 ligand (Flt3L), 20 ng/ml interleukin 4 (IL-4) and 100 ng/ml stem cell factor (SCF). The low GM-CSF control group was cultured with 0.4 ng/ml GM-CSF, 25 ng/ml FIt3L and 100 ng/ml SCF, without IL-4. The control group without exogenous cytokines was cultured without dditional cytokines. All cells were cultured at 37℃ under 5% CO2. On days 3, 7 and 16, 4-color flow cytometry was carried out to analyze the cell phenotypes, and the total cell numbers were counted to analyze the cell yields. Phase-contrast microscopy was used to observe the cell morphologies.Results The cytokine group exhibited higher proportions f typical immature CD8a+ DC, especially on day 3, but the total cell number and DC2 proportion decreased during prolonged culture. The low GM-CSF control group showed the same tendencies as the cytokine group on days 16 and 22, but produced higher total cell numbers (P <0.05) with lower DC2 proportions and cell numbers. The control group without exogenous cytokines spontaneously generated a certain proportion of DC2, but with low total cell and DC2 numbers that decreased rapidly, especially during prolonged culture (days 7 and 16, P <0.05).Conclusions Culture in the presence of 5 ng

  10. Institusion Investors' Optimal Liquidation Strategy%机构投资者的最优变现策略

    Institute of Scientific and Technical Information of China (English)

    王秀红; 陈贵霞

    2012-01-01

    Relative to ordinary investor, the institution investor processing a large block asset , when transact the asset will make the unilateral change of the asset price, which can cause the liquidity risk. With the assumption that the stock' s price followed the geometric Brown motion, it analysed the optimal liquidation strategy of complete liquidation action under the stochastic impact, and studied the problem of the optimal liquidation strategy by minimum principle in optimal control theory. The optimal liquidation strategy is decided by market price volatility, asset liquidity and institutional investor' s risk aversion preference. Take shenfazhan stock for example, Institution investor need to select the right optimal liquidation strategy to bring down the liquidity risk at the market, they can get more profits.%相对于普通投资者,大规模持有某种资产的机构投资者在交易这种资产时,其行为会导致资产价格的单向变动,从而产生流动性风险.针对机构投资者在连续时间框架且股票价格服从几何布朗运动的情况,提出在随机冲击下其完全变现行为的最优变现策略,利用最优控制理论中的极小值原理研究其最优变现策略.敏感性分析表明,最优变现策略由市场价格波动率、资产的流动性和机构投资者的风险厌恶偏好共同决定.以深发展股票为例,验证了机构投资者在随机冲击下可根据上述结论选择合适的最优变现策略,降低其在市场中所面临的流动性风险,使得股票的账面价值更可能多的转换为实际收益.

  11. Direct comparison of Xpert MTB/RIF assay with liquid and solid mycobacterial culture for quantification of early bactericidal activity

    NARCIS (Netherlands)

    Kayigire, X.A.; Friedrich, S.O.; Venter, A.; Dawson, R.; Gillespie, S.H.; Boeree, M.J.; Heinrich, N.; Hoelscher, M.; Diacon, A.H.; Aarnoutse, R.

    2013-01-01

    The early bactericidal activity of antituberculosis agents is usually determined by measuring the reduction of the sputum mycobacterial load over time on solid agar medium or in liquid culture. This study investigated the value of a quantitative PCR assay for early bactericidal activity determinatio

  12. Inducing effects of macrophage stimulating protein on the expansion of early hematopoietic progenitor cells in liquid culture

    Institute of Scientific and Technical Information of China (English)

    MA Li-xia; HUANG Yan-hong; CHENG La-mei; LEI Jun; WANG Qi-ru

    2007-01-01

    Background Macrophage stimulating protein (MSP) is produced by human bone marrow endothelial cells. In this study,we sought to observe its effects on inducing the expansion of early hematopoietic progenitor cells which were cultured in a liquid culture system in the presence of the combination of stem cell factor (SCF), interleukin 3 (IL-3), interleukin 6 (IL-6), granulocyte macrophage-colony stimulating factor (GM-CSF), erythropoietin (EPO) (Cys) and MSP or of Cys and bone marrow endothelial cell conditioned medium (EC-CM).Methods Human bone marrow CD34+ cells were separated and cultured in a liquid culture system for 6 days.Granulocyte-macrophage colony forming unit (CFU-GM) and colony forming unit-granulocyte, erythrocyte, macrophage,megakaryocyte (CFU-GEMM) were employed to assay the effects of different treatment on the proliferation of hematopoeitic stem/progenitor cells. The nitroblue tetrazolium (NBT) reductive test and hoechest 33258 staining were employed to reflect the differentiation and apoptosis of the cells respectively.Results MSP inhibited the proliferation of CFU-GM and CFU-GEMM in semi-solid culture and the inhibitory effect on CFU-GEMM was stronger than on CFU-GM. MSP inhibited the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators. Bone marrow (BM) CFU-GEMM was 2.3-fold or 1.7-fold increase or significantly decreased in either Cys+EC-CM, Cys+MSP or Cys compared with 0 hour control in liquid culture system after 6 days.Conclusion MSP, a hematopoietic inhibitor, inhibits the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators and makes the early hematopoietic progenitor cells expand in a liquid culture system.

  13. Development and population dynamics of Steinernema yirgalemense (Rhabditida: Steinernematidae) and growth characteristics of its associated Xenorhabdus indica symbiont in liquid culture.

    Science.gov (United States)

    Ferreira, T; Addison, M F; Malan, A P

    2016-05-01

    Entomopathogenic nematodes have become a valuable addition to the range of biological control agents available for insect control. An endemic nematode, Steinernema yirgalemense, has been found to be effective against a wide range of key insect pests. The next step would be the mass production this nematode for commercial application. This requires the establishment of monoxenic cultures of both the nematode and the symbiotic bacterium Xenorhabdus indica. First-stage juveniles of S. yirgalemense were obtained from eggs, while X. indica was isolated from nematode-infected wax moth larvae. The population density of the various life stages of S. yirgalemense during the developmental phase in liquid culture was determined. The recovery of infective juveniles (IJs) to the third-stage feeding juveniles, was 67 ± 10%, reaching a maximum population density of 75,000 IJs ml- 1 on day 13 after inoculation. Adult density increased after 8 days, with the maximum female density being 4600 ml- 1 on day 15, whereas the maximum male density was 4300 ml- 1 on day 12. Growth curves for X. indica showed that the exponential phase was reached 15 h after inoculation to the liquid medium. The stationary phase was reached after 42 h, with an average of 51 × 107 colony-forming units ml- 1. Virulence tests showed a significant difference in insect mortality between in vitro- and in vivo-produced nematodes. The success obtained with the production of S. yirgalemense in liquid culture can serve as the first step in the optimizing and upscaling of the commercial production of nematodes in fermenters.

  14. Enhancing inulinase yield by irradiation mutation associated with optimization of culture conditions

    Directory of Open Access Journals (Sweden)

    Yafeng Gou

    2015-09-01

    Full Text Available A new inulinase-producing strain was isolated from rhizosphere soils of Jerusalem artichoke collected from Shihezi (Xinjiang, China using Jerusalem artichoke power (JAP as sole carbon source. It was identified as an Aspergillus niger strain by analysis of 16S rRNA. To improve inulinase production, this fungus was subjected to mutagenesis induced by 60Co γ-irradiation. A genetically stable mutant (designated E12 was obtained and it showed 2.7-fold higher inulinase activity (128 U/mL than the parental strain in the supernatant of a submerged culture. Sequential methodology was used to optimize the inulinase production of stain E12. A screening trial was first performed using Plackett-Burman design and variables with statistically significant effects on inulinase bio-production were identified. These significant factors were further optimized by central composite design experiments and response surface methodology. Finally, it was found that the maximum inulinase production (185 U/mL could be achieved under the optimized conditions namely pH 7.0, yeast extract concentration of 5.0 g/L, JAP concentration of 66.5 g/L, peptone concentration of 29.1 g/L, solution volume of 49.4 mL in 250-mL shake flasks, agitation speed of 180 rpm, and fermentation time of 60 h. The yield of inulinase under optimized culture conditions was approximately 1.4-fold of that obtained by using basal culture medium. These findings are of significance for the potential industrial application of the mutant E12.

  15. High performance liquid chromatographic determination of ultra traces of two tricyclic antidepressant drugs imipramine and trimipramine in urine samples after their dispersive liquid-liquid microextraction coupled with response surface optimization.

    Science.gov (United States)

    Shamsipur, Mojtaba; Mirmohammadi, Mehrosadat

    2014-11-01

    Dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography by ultraviolet detection (HPLC-UV) as a fast and inexpensive technique was applied to the determination of imipramine and trimipramine in urine samples. Response surface methodology (RSM) was used for multivariate optimization of the effects of seven different parameters influencing the extraction efficiency of the proposed method. Under optimized experimental conditions, the enrichment factors and extraction recoveries were between 161.7-186.7 and 97-112%, respectively. The linear range and limit of detection for both analytes found to be 5-100ng mL(-1) and 0.6ng mL(-1), respectively. The relative standard deviations for 5ng mL(-1) of the drugs in urine samples were in the range of 5.1-6.1 (n=5). The developed method was successfully applied to real urine sample analyses.

  16. Optimizing culture conditions for free-living stages of the nematode parasite Strongyloides ratti.

    Science.gov (United States)

    Dulovic, Alex; Puller, Vadim; Streit, Adrian

    2016-09-01

    The rat parasitic nematode Strongyloides ratti (S. ratti) has recently emerged as a model system for various aspects of parasite biology and evolution. In addition to parasitic parthenogenetic females, this species can also form facultative free-living generations of sexually reproducing adults. These free-living worms are bacteriovorous and grow very well when cultured in the feces of their host. However, in fecal cultures the worms are rather difficult to find for observation and experimental manipulation. Therefore, it has also been attempted to raise S. ratti on Nematode Growth Media (NGM) plates with Escherichia coli OP50 as food, exactly as described for the model nematode Caenorhabditis elegans. Whilst worms did grow on these plates, their longevity and reproductive output compared to fecal cultures were dramatically reduced. In order to improve the culture success we tested other plates occasionally used for C. elegans and, starting from the best performing one, systematically varied the plate composition, the temperature and the food in order to further optimize the conditions. Here we present a plate culturing protocol for free-living stages of S. ratti with strongly improved reproductive success and longevity.

  17. Optimal control for nonlinear dynamical system of microbial fed-batch culture

    Science.gov (United States)

    Liu, Chongyang

    2009-10-01

    In fed-batch culture of glycerol bio-dissimilation to 1, 3-propanediol (1, 3-PD), the aim of adding glycerol is to obtain as much 1, 3-PD as possible. So a proper feeding rate is required during the process. Taking the concentration of 1, 3-PD at the terminal time as the performance index and the feeding rate of glycerol as the control function, we propose an optimal control model subject to a nonlinear dynamical system and constraints of continuous state and non-stationary control. A computational approach is constructed to seek the solution of the above model in two aspects. On the one hand we transcribe the optimal control model into an unconstrained one based on the penalty functions and an extension of the state space; on the other hand, by approximating the control function with simple functions, we transform the unconstrained optimal control problem into a sequence of nonlinear programming problems, which can be solved using gradient-based optimization techniques. The convergence analysis of this approximation is also investigated. Numerical results show that, by employing the optimal control policy, the concentration of 1, 3-PD at the terminal time can be increased considerably.

  18. Insights into an Optimization of Plasmodium vivax Sal-1 In Vitro Culture: The Aotus Primate Model.

    Science.gov (United States)

    Shaw-Saliba, Kathryn; Thomson-Luque, Richard; Obaldía, Nicanor; Nuñez, Marlon; Dutary, Sahir; Lim, Caeul; Barnes, Samantha; Kocken, Clemens H M; Duraisingh, Manoj T; Adams, John H; Pasini, Erica M

    2016-07-01

    Malaria is one of the most significant tropical diseases, and of the Plasmodium species that cause human malaria, P. vivax is the most geographically widespread. However, P. vivax remains a relatively neglected human parasite since research is typically limited to laboratories with direct access to parasite isolates from endemic field settings or from non-human primate models. This restricted research capacity is in large part due to the lack of a continuous P. vivax in vitro culture system, which has hampered the ability for experimental research needed to gain biological knowledge and develop new therapies. Consequently, efforts to establish a long-term P. vivax culture system are confounded by our poor knowledge of the preferred host cell and essential nutrients needed for in vitro propagation. Reliance on very heterogeneous P. vivax field isolates makes it difficult to benchmark parasite characteristics and further complicates development of a robust and reliable culture method. In an effort to eliminate parasite variability as a complication, we used a well-defined Aotus-adapted P. vivax Sal-1 strain to empirically evaluate different short-term in vitro culture conditions and compare them with previous reported attempts at P. vivax in vitro culture Most importantly, we suggest that reticulocyte enrichment methods affect invasion efficiency and we identify stabilized forms of nutrients that appear beneficial for parasite growth, indicating that P. vivax may be extremely sensitive to waste products. Leuko-depletion methods did not significantly affect parasite development. Formatting changes such as shaking and static cultures did not seem to have a major impact while; in contrast, the starting haematocrit affected both parasite invasion and growth. These results support the continued use of Aotus-adapted Sal-1 for development of P. vivax laboratory methods; however, further experiments are needed to optimize culture conditions to support long-term parasite

  19. Optimization of pressurized liquid extraction of carotenoids and chlorophylls from Chlorella vulgaris.

    Science.gov (United States)

    Cha, Kwang Hyun; Lee, Hee Ju; Koo, Song Yi; Song, Dae-Geun; Lee, Dong-Un; Pan, Cheol-Ho

    2010-01-27

    Pressurized liquid extraction (PLE) was applied to the extraction of carotenoids and chlorophylls from the green microalga Chlorella vulgaris. Four extraction techniques such as maceration (MAC), Soxhlet extraction (SOX), ultrasound assisted extraction (UAE), and PLE were compared, and both the extraction temperature (50, 105, and 160 degrees C) and the extraction time (8, 19, and 30 min), which are the two main factors for PLE, were optimized with a central composite design to obtain the highest extraction efficiency. The extraction solvent (90% ethanol/water) could adequately extract the functional components from C. vulgaris. PLE showed higher extraction efficiencies than MAC, SOX, and UAE. Temperature was the key parameter having the strongest influence on the extraction of carotenoids and chlorophylls from chlorella. In addition, high heat treatment (>110 degrees C) by PLE minimized the formation of pheophorbide a, a harmful chlorophyll derivative. These results indicate that PLE may be a useful extraction method for the simultaneous extraction of carotenoids and chlorophylls from C. vulgaris.

  20. Evaluation and optimization of hepatocyte culture media factors by design of experiments (DoE) methodology.

    Science.gov (United States)

    Dong, Jia; Mandenius, Carl-Fredrik; Lübberstedt, Marc; Urbaniak, Thomas; Nüssler, Andreas K N; Knobeloch, Daniel; Gerlach, Jörg C; Zeilinger, Katrin

    2008-07-01

    Optimization of cell culture media based on statistical experimental design methodology is a widely used approach for improving cultivation conditions. We applied this methodology to refine the composition of an established culture medium for growth of a human hepatoma cell line, C3A. A selection of growth factors and nutrient supplements were systematically screened according to standard design of experiments (DoE) procedures. The results of the screening indicated that the medium additives hepatocyte growth factor, oncostatin M, and fibroblast growth factor 4 significantly influenced the metabolic activities of the C3A cell line. Surface response methodology revealed that the optimum levels for these factors were 30 ng/ml for hepatocyte growth factor and 35 ng/ml for oncostatin M. Additional experiments on primary human hepatocyte cultures showed high variance in metabolic activities between cells from different individuals, making determination of optimal levels of factors more difficult. Still, it was possible to conclude that hepatocyte growth factor, epidermal growth factor, and oncostatin M had decisive effects on the metabolic functions of primary human hepatocytes.

  1. Geographic differences in time to culture conversion in liquid media: Tuberculosis Trials Consortium study 28. Culture conversion is delayed in Africa.

    Directory of Open Access Journals (Sweden)

    William R Mac Kenzie

    Full Text Available BACKGROUND: Tuberculosis Trials Consortium Study 28, was a double blind, randomized, placebo-controlled, phase 2 clinical trial examining smear positive pulmonary Mycobacterium tuberculosis. Over the course of intensive phase therapy, patients from African sites had substantially delayed and lower rates of culture conversion to negative in liquid media compared to non-African patients. We explored potential explanations of this finding. METHODS: In TBTC Study 28, protocol-correct patients (n = 328 provided spot sputum specimens for M. tuberculosis culture in liquid media, at baseline and weeks 2, 4, 6 and 8 of study therapy. We compared sputum culture conversion for African and non-African patients stratified by four baseline measures of disease severity: AFB smear quantification, extent of disease on chest radiograph, cavity size and the number of days to detection of M. tuberculosis in liquid media using the Kaplan-Meier product-limit method. We evaluated specimen processing and culture procedures used at 29 study laboratories serving 27 sites. RESULTS: African TB patients had more extensive disease at enrollment than non-African patients. However, African patients with the least disease by the 4 measures of disease severity had conversion rates on liquid media that were substantially lower than conversion rates in non-African patients with the greatest extent of disease. HIV infection, smoking and diabetes did not explain delayed conversion in Africa. Some inter-site variation in laboratory processing and culture procedures within accepted practice for clinical diagnostic laboratories was found. CONCLUSIONS: Compared with patients from non-African sites, African patients being treated for TB had delayed sputum culture conversion and lower sputum conversion rates in liquid media that were not explained by baseline severity of disease, HIV status, age, smoking, diabetes or race. Further investigation is warranted into whether modest

  2. Optimization of Betanodavirus culture and enumeration in striped snakehead fish cells.

    Science.gov (United States)

    Hick, Paul; Tweedie, Alison; Whittington, Richard J

    2011-05-01

    An optimized culture method for detection of infection of fish with the Red spotted grouper nervous necrosis virus (RGNNV) genotype of betanodavirus in striped snakehead (SSN-1, Channa striatus) cells is described. Inoculation of fish tissue homogenates at the same time or within 4 hr of seeding the SSN-1 cells was as sensitive as the method recommended by the World Organization for Animal Health, where homogenates were adsorbed onto an established cell monolayer. Such modification halved the time required and the costs of consumables, and reduced the potential for error when processing large numbers of samples. Positive culture results were obtained from 88.3% of 392 fish tissue homogenates in which RGNNV was detected using a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay; 99.7% of 943 tissue homogenates, which were qRT-PCR negative, were cell culture negative. Cytopathic effect (CPE) was characterized by large intracytoplasmic vacuoles in 0.1-60% of cells. Detachment of affected cells from the culture surface resulting in progressive disruption of the monolayer occurred in 46.4% of primary cultures and 96.0% of subcultures of positive samples. Identification of CPE that did not disrupt the cell monolayer increased estimates of the 50% tissue culture infective dose (TCID(50)) by 1.07-2.79 logs (95% confidence interval). The predicted mean TCID(50)/ml was 3.3 logs higher when cells were inoculated less than 36 hr after subculture at less than 80% confluence compared to cells inoculated at greater than 80% confluence and more than 36 hr after subculture (P < 0.05).

  3. Optimization of dispersive liquid-liquid microextraction for the selective determination of trace amounts of palladium by flame atomic absorption spectroscopy.

    Science.gov (United States)

    Kokya, Taher Ahmadzadeh; Farhadi, Khalil

    2009-09-30

    A new simple and reliable method for rapid and selective extraction and determination of the trace levels of Pd(2+) ion was developed by dispersive liquid-liquid microextraction preconcentration and flame atomic absorption spectrometry detection. In the proposed approach, thioridazine HCl (TRH) was used as a Pd(2+) ion selective complexing agent. The effective parameters on the extraction recovery were studied and optimized utilizing two decent optimization methods; factorial design and central composite design (CCD). Through factorial design the best efficiency of extraction acquired using ethanol and chloroform as dispersive and extraction solvents respectively. CCD optimization resulted in 1.50 mL of dispersive solvent; 0.15 mL of extraction solvent; 0.45 mg of TRH and 250 mg of potassium chloride salt per 5 mL of sample solution. Under the optimum conditions the calibration graph was linear over the range 100-2000 microgL(-1). The average relative standard deviation was 0.7% for five repeated determinations. The limit of detection was 90 microg L(-1). The average enrichment factor and recovery reached 45.7% and 74.2% respectively. The method was successfully applied to the determination of trace amounts of palladium in the real water samples.

  4. Monitoring the oleuropein content of olive leaves and fruits using ultrasound- and salt-assisted liquid-liquid extraction optimized by response surface methodology and high-performance liquid chromatography.

    Science.gov (United States)

    Ismaili, Ahmad; Heydari, Rouhollah; Rezaeepour, Reza

    2016-01-01

    A novel and rapid ultrasound- and salt-assisted liquid-liquid extraction coupled with high-performance liquid chromatography has been optimized by response surface methodology for the determination of oleuropein from olive leaves. Box-Behnken design was used for optimizing the main parameters including ultrasound time (A), pH (B), salt concentration (C), and volume of miscible organic solvent (D). In this technique, a mixture of plant sample and extraction solvent was subjected to ultrasound waves. After ultrasound-assisted extraction, phase separation was performed by the addition of salt to the liquid phase. The optimal conditions for the highest extraction yield of oleuropein were ultrasound time, 30 min; volume of organic solvent, 2.5 mL; salt concentration, 25% w/v; and sample pH, 4. Experimental data were fitted with a quadratic model. Analysis of variance results show that BC interaction, A(2) , B(2) , C(2) , and D(2) are significant model terms. Unlike the conventional extraction methods for plant extracts, no evaporation and reconstitution operations were needed in the proposed technique.

  5. Optimized “In Vitro” Culture Conditions for Human Rheumatoid Arthritis Synovial Fibroblasts

    Directory of Open Access Journals (Sweden)

    Claudia Casnici

    2014-01-01

    Full Text Available The composition of synovial fluid in rheumatoid arthritis (RA is complex and strongly influences the microenvironment of joints and it is an inseparable element of the disease. Currently, “in vitro” studies are performed on RA cells cultured in the presence of either recombinant proinflammatory cytokines-conditioned medium or medium alone. In this study, we evaluated the use of synovial fluid, derived from RA patients, as optimal culture condition to perform “in vitro” studies on RA synovial fibroblasts. We observed that synovial fluid is more effective in inducing cell proliferation with respect to TNF-alpha or culture medium alone. Spontaneous apoptosis in fibroblasts was also decreased in response to synovial fluid. The expression of proinflammatory cytokines in the presence of synovial fluid was significantly elevated with respect to cells cultured with TNF-alpha or medium, and the overall morphology of cells was also modified. In addition, modulation of intracellular calcium dynamics elicited in response to synovial fluid or TNF-alpha exposure is different and suggests a role for the purinergic signalling in the modulation of the effects. These results emphasize the importance of using RA synovial fluid in “in vitro” studies involving RA cells, in order to reproduce faithfully the physiopathological environmental characteristic of RA joints.

  6. Application of response surface method for optimization of dispersive liquid-liquid microextraction of water-soluble components of Rosa damascena Mill. essential oil.

    Science.gov (United States)

    Sereshti, Hassan; Karimi, Maryam; Samadi, Soheila

    2009-01-09

    Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was applied for the determination of Rose water constituents. The effective parameters such as volume of extraction and disperser solvents, temperature, and salt effect were inspected by a full factorial design to identify important parameters and their interactions. It showed that salt addition had no effect on the efficiency. Next, a central composite design was applied to obtain optimum point of the important parameters. The optimal condition was obtained as 37.0 microL for extractor, 0.42 mL for disperser and temperature for 48 degrees C. The main components that were extracted at the optimum point were benzeneethanol (24.87%), geraniol (23.07%), beta-citronellol (22.38%), nerol (8.48%), eugenol (5.98%) and linalool (5.62%).

  7. Optimizing N-Fixing cyanobacteria culture to restore arid degraded soils

    Science.gov (United States)

    Roncero-Ramos, Beatriz; Román, Raúl; Gómez, Cintia; Chamizo, Sonia; Rodriguez-Caballero, Emilio; Cantón, Yolanda

    2017-04-01

    Cyanobacteria present several metabolic activities and mechanisms of adaptation which enable them to colonize different habitats, in almost all biome and continents, especially under extreme environmental conditions, as on the surface of the most arid soils and under the highest temperatures. In drylands, they are usually found among plants, cohabiting with organisms such as algae, lichens, mosses, bacteria and fungi, and in association with soil surface particles, forming communities known as biocrusts. Because they can survive under water stress and are considered ecosystem engineers, facilitating the establishment of other organisms, they can play a key role in the development of a successful restoration approach to recover the functionality of soils in arid and semiarid regions. In addition cyanobacteria can be cultured "ex-situ" obtaining high quantities of biomass to be used as soil inoculum at large scale. For these reasons, the inoculation of degrades soils with cyanobacteria can be considered an alternative to traditional restoration. This approach is expected to promote: the stabilization of the soil surface and the decrease of water and wind erosion; the increase of soil fertility by fixing N and C; and the succession of more developed organisms as mosses or vascular and annual plants. The objectives were: to evaluate the potential of a soil native cyanobacteria strain to be artificially cultured and the optimization of the process, and to analyze the effects of the inoculation of the biomass on soil under laboratory conditions. Cyanobacteria were isolated from biocrusts sampled on a limestone quarry located at the southeastern edge of the Sierra de Gádor massif (Spain). It was genetically and morphological identified as belonging to the nitrogen-fixing genera Nostoc. Essays were accomplished in bubble columns reactors (0.25 L), using different culture media: BG11+N, BG110, and two media made with fertilizers. Illumination simulated a circadian cycle

  8. EFFECTS OF STOCK SPLIT ON STOCK LIQUIDITY AND STOCK PRICE OPTIMALITY OF COMPANIES QUOTED AT NAIROBI STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    MR. SIMON KAMAU GATEI

    2012-11-01

    Full Text Available A number of researchers have found a stock split is normally followed by either positive abnormal returns or increased stock liquidity or both. However other researchers such as Murray (1985 and Bley (2002 found results that are contrary to this. The objective of this paper was to assess the consequence of stock splits on stock liquidity of Kenyan firms quoted at the NSE.The research was a causal study with a trend analytical design aimed at determining the relationship between the stock liquidity positions as a result of the stock split event. The population consisted of all companies quoted in the NSE that had undertaken a stock split between the years of 2005 and 2011. The data used was secondary data on daily volumes of stock traded and daily closing stock prices that was retrieved from the NSE website. The model used for data analysis was the Amivest liquidity ratio which was developed by cooper Groth and Avera (1985. This model measured the shillings volume traded for each 1% change in stock price. The data analysis package used was Excel spread sheet.The results from the study found out that generally the liquidity of stock, as measured by the Amivest liquidity ratio, is relatively higher in the days before the stock split than in the days after the stock split. It was also observed that liquidity tends to be lowest in the days around the stock split. Generally the aggregate liquidity position in the month before the stock split was found to be higher than in the month after the stock split.It was also observed that after the stock split, stock price showed optimality by trading at a relatively constant stock price in almost all the companies.

  9. Cross-Cultural Comparison of the Effects of Optimism, Intrinsic Motivation, and Family Relations on Vocational Identity

    Science.gov (United States)

    Shin, Yun-Jeong; Kelly, Kevin R.

    2013-01-01

    This study explored the effects of optimism, intrinsic motivation, and family relations on vocational identity in college students in the United States and South Korea. The results yielded support for the hypothesized multivariate model. Across both cultures, optimism was an important contributing factor to vocational identity, and intrinsic…

  10. Cross-Cultural Comparison of the Effects of Optimism, Intrinsic Motivation, and Family Relations on Vocational Identity

    Science.gov (United States)

    Shin, Yun-Jeong; Kelly, Kevin R.

    2013-01-01

    This study explored the effects of optimism, intrinsic motivation, and family relations on vocational identity in college students in the United States and South Korea. The results yielded support for the hypothesized multivariate model. Across both cultures, optimism was an important contributing factor to vocational identity, and intrinsic…

  11. Study on Hydroxyurea Response in Hemoglobinopathies Patients Using Genetic Markers and Liquid Erythroid Cultures

    Science.gov (United States)

    Sclafani, Serena; Agrigento, Veronica; Troia, Antonio; Di Maggio, Rosario; Sacco, Massimiliano; Maggio, Aurelio; D’Alcamo, Elena; Di Marzo, Rosalba

    2016-01-01

    Increased expression of fetal hemoglobin (HbF) may ameliorate the clinical course of hemoglobinopathies. Hydroxyurea (HU) is the only inducer approved for the treatment of these diseases able to stimulate HbF production but patients’ response is highly variable indicating the utility of the identification of pharmacogenomic biomarkers in order to predict pharmacological treatment efficacy. To date few studies to evaluate the role of genetic determinants in HU response have been conducted showing contradictory results. In this study we analyzed BCL11A, GATA-1, KLF-1 genes and γ-globin promoter in 60 alleles from 30 hemoglobinopathies patients under HU treatment to assess the role of these markers in HU response. We did not find any association between these genetic determinants and HU response. Before treatment started, the same patients were analyzed in vitro using liquid erythroid cultures in a test able to predict their response to HU. The results of our analysis confirm the absence of pharmacogenomic biomarker associated to HU response indicating that, the quantification of γ-globin mRNA fold increase remains the only method able to predict in vivo patients response to the drug. PMID:28053695

  12. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    Science.gov (United States)

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  13. Genetic Algorithmic Optimization of PHB Production by a Mixed Culture in an Optimally Dispersed Fed-batch Bioreactor

    Directory of Open Access Journals (Sweden)

    Pratap R. Patnaik

    2009-10-01

    Full Text Available Poly-β-hydroxybutyrate (PHB is an energy-storage polymer whose properties are similar to those of chemical polymers such as polyethylene and polypropylene. Moreover, PHB is biodegradable, absorbed by human tissues and less energy-consuming than synthetic polymers. Although Ralstonia eutropha is widely used to synthesize PHB, it is inefficient in utilizing glucose and similar sugars. Therefore a co-culture of R. eutropha and Lactobacillus delbrueckii is preferred since the latter can convert glucose to lactate, which R. eutropha can metabolize easily. Tohyama et al. [24] maximized PHB production in a well-mixed fed-batch bioreactor with glucose and (NH42SO4 as the primary substrates. Since production-scale bioreactors often deviate from ideal laboratory-scale reactors, a large bioreactor was simulated by means of a dispersion model with the kinetics determined by Tohyama et al. [24] and dispersion set at an optimum Peclet number of 20 [32]. The time-dependent feed rates of the two substrates were determined through a genetic algorithm (GA to maximize PHB production. This bioreactor produced 22.2% more PHB per liter and 12.8% more cell mass than achieved by Tohyama et al. [24]. These results, and similar observations with other fermentations, indicate the feasibility of enhancing the efficiency of large nonideal bioreactors through GA optimizations.

  14. Development and Optimization of a Flocculation Procedure for Improved Solid-Liquid Separation of Digested Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Caroline; Lischeske, James J.; Sievers, David A.

    2015-11-03

    One viable treatment method for conversion of lignocellulosic biomass to biofuels begins with saccharification (thermochemical pretreatment and enzymatic hydrolysis), followed by fermentation or catalytic upgrading to fuels such as ethanol, butanol, or other hydrocarbons. The post-hydrolysis slurry is typically 4-8 percent insoluble solids, predominantly consisting of lignin. Suspended solids are known to inhibit fermentation as well as poison catalysts and obstruct flow in catalyst beds. Thus a solid-liquid separation following enzymatic hydrolysis would be highly favorable for process economics, however the material is not easily separated by filtration or gravimetric methods. Use of a polyacrylamide flocculant to bind the suspended particles in a corn stover hydrolyzate slurry into larger flocs (1-2mm diameter) has been found to be extremely helpful in improving separation. Recent and ongoing research on novel pretreatment methods yields hydrolyzate material with diverse characteristics. Therefore, we need a thorough understanding of rapid and successful flocculation design in order to quickly achieve process design goals. In this study potential indicators of flocculation performance were investigated in order to develop a rapid analysis method for flocculation procedure in the context of a novel hydrolyzate material. Flocculation conditions were optimized on flocculant type and loading, pH, and mixing time. Filtration flux of the hydrolyzate slurry was improved 170-fold using a cationic polyacrylamide flocculant with a dosing of approximately 22 mg flocculant/g insoluble solids at an approximate pH of 3. With cake washing, sugar recovery exceeded 90 percent with asymptotic yield at 15 L wash water/kg insoluble solids.

  15. Geometry optimization of a fibrous scaffold based on mathematical modelling and CFD simulation of a dynamic cell culture

    DEFF Research Database (Denmark)

    Tajsoleiman, Tannaz; J. Abdekhodaie, Mohammad; Gernaey, Krist

    2016-01-01

    simulation of cartilage cell culture under a perfusion flow, which allows not only to characterize the supply of nutrients and metabolic products inside a fibrous scaffold, but also to assess the overall culture condition and predict the cell growth rate. Afterwards, the simulation results supported finding...... an optimized design of the scaffold within a new mathematical optimization algorithm that is proposed. The main concept of this optimization routine isto maintain a large effective surface while simultaneously keeping the shear stress levelin an operating range that is expected to be supporting growth...

  16. Researches concerning in vitro cultures optimization of the vulnerable species Dianthus nardiformis Janka

    Directory of Open Access Journals (Sweden)

    Irina HOLOBIUC

    2010-05-01

    Full Text Available Our aim was to establish an optimized protocol for in vitro short-term conservation of the vulnerable species Dianthus nardiformis Janka belonging to Romanian Flora.For our purpose, different culture media compositions were tested: complex variants added with plant growth regulators and simplified media with low levels of macro- and microelements.This species had a good in vitro reaction, the regeneration occurs through direct morphogenesis as in all Dianthus species. Generally, the use of variants of MS medium supplemented with cytokinin/ auxin at 10/1 ratio proved to induce high regeneration response starting from the first month of culture.In our study, MS media complex variants with diminished levels of plant growth hormones at the same ratio of cytokinins/auxins conducted to acceptable levels of regeneration.By the other hand on complex regeneration variants, the rooting process was absent or underwent at low levels.Using simplified media with reduced levels of macro- and microelements, both rhizogenesis and shoots formation were induced. The in vitro response was characterized through the mean number of regenerated shoots/explants and the mean number of neoformed roots/initial inoculum. Despite of low micro- and macroelements levels (1/2 and 1/4 of MS salts, the modified MS basal medium composition proved to be beneficial for D. nardiformis, plants could be efficiently regenerated and rooted and regenerative aggregates can also be propagated as short-term cultures. The need of the supplementary transfer on particular rooting medium is also eliminated.Using simplified culture media, this species can be efficiently micropropagated and maintained as active tissue cultures, able tosupply viable plants whenever it is necessary.

  17. Optimization of single-cell electroporation protocol for forced gene expression in primary neuronal cultures.

    Science.gov (United States)

    Nishikawa, Shin; Hirashima, Naohide; Tanaka, Masahiko

    2014-09-01

    The development and function of the central nervous system (CNS) are realized through interactions between many neurons. To investigate cellular and molecular mechanisms of the development and function of the CNS, it is thus crucial to be able to manipulate the gene expression of single neurons in a complex cell population. We recently developed a technique for gene silencing by introducing small interfering RNA into single neurons in primary CNS cultures using single-cell electroporation. However, we had not succeeded in forced gene expression by introducing expression plasmids using single-cell electroporation. In the present study, we optimized the experimental conditions to enable the forced expression of green fluorescent protein (GFP) in cultured cerebellar Purkinje neurons using single-cell electroporation. We succeeded in strong GFP expression in Purkinje neurons by increasing the inside diameter of micropipettes or by making the size of the original plasmid smaller by digestion and cyclizing it by ligation. Strong GFP expression in Purkinje neurons electroporated under the optimal conditions continued to be observed for more than 25 days after electroporation. Thus, this technique could be used for forced gene expression in single neurons to investigate cellular and molecular mechanisms of the development, function, and disease of the CNS.

  18. Simulation and Optimization of Strengthening the Gas-Liquid Mass Transfer Structure in Tray Column

    Directory of Open Access Journals (Sweden)

    Duan Jihai

    2015-01-01

    Full Text Available This paper presented the analysis of the effect of the mesh layers, installation height and opening rate on gas-liquid two-phase flow field by numerical simulation, which based on Euler-Euler model and identified the best liquid-gas ratio. The simulation results showed that: when the installation height of the square mesh was 25 mm and opening rate was 55.7%, the gas holdup distribution in the upper part of the mesh became higher and improved the liquid velocity distribution. Meanwhile, the gas-liquid distribution on trays was more uniform.

  19. Biodegradation of Alachlor in Liquid and Soil Cultures Under Variable Carbon and Nitrogen Sources by Bacterial Consortium Isolated from Corn Field Soil

    Directory of Open Access Journals (Sweden)

    Simin Nasseri

    2013-03-01

    Full Text Available Alachlor, an aniline herbicide widely used in corn production, is frequently detected in water resources. The main objectives of this research were focused on isolating bacterial consortium capable of alachlor biodegradation, assessing the effects of carbon and nitrogen sources on alachlor biodegradation and evaluating the feasibility of using bacterial consortium in soil culture. Kavar corn field soil with a long history of alachlor application in Fars province of Iran has been explored for their potential of alachlor biodegradation. The influence of different carbon compounds (glucose, sodium citrate, sucrose, starch and the combination of these compounds, the effect of nitrogen sources (ammonium nitrate and urea and different pH (5.5-8.5 on alachlor removal efficiency by the bacterial consortium in liquid culture were investigated. After a multi-step enrichment program 100 days of acclimation, a culture with the high capability of alachlor degradation was obtained (63%. Glucose and sodium citrate had the highest alachlor reduction rate (85%. Alachlor reduction rate increased more rapidly by the addition of ammonium nitrate (94% compare to urea. Based on the data obtained in the present study, pH of 7.5 is optimal for alachlor biodegradation. After 30 days of incubation, the percent of alachlor reduction were significantly enhanced in the inoculated soils (74% as compared to uninoculated control soils (17.67% at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with bacterial consortium may enhance the rate of alachlor degradation in a polluted soil.

  20. An Axenic Plant Culture System for Optimal Growth in Long-Term Studies: Design and Maintenance

    Science.gov (United States)

    Henry, Amelia; Doucette, William; Norton, Jeanette; Jones, Scott; Chard, Julie; Bugbee, Bruce

    2006-01-01

    The symbiotic co-evolution of plants and microbes leads to difficulties in understanding which of the two components is responsible for a given environmental response. Plant-microbe studies greatly benefit from the ability to grow plants in axenic (sterile) culture. Several studies have used axenic plant culture systems, but experimental procedures are often poorly documented, the plant growth environment is not optimal, and axenic conditions are not rigorously verified. We developed a unique axenic system using inert components that promotes plant health and can be kept sterile for at least 70 d. Crested wheatgrass (Agropyron cristatum cv. DII) plants were grown in sand within flow-through glass columns that were positively pressured with filtered air. Plant health was optimized by regulating temperature, light level, CO2 concentration, humidity, and nutrients. The design incorporates several novel aspects, such as pretreatment of the sand with Fe, graduated sand layers to optimize the air-water balance of the root zone, and modification of a laminar flow hood to serve as a plant growth chamber. Adaptations of several sterile techniques were necessary for maintenance of axenic conditions. Axenic conditions were verified by plating and staining leachates as well as rhizoplane stain. This system was designed to study nutrient and water stress effects on root exudates, but is useful for assessing a broad range of plant-microbe-environment interactions. Based on total organic C analysis, 74% of exudates was recovered in the leachate, 6% was recovered in the bulk sand, and 17% was recovered in the rhizosphere sand. Carbon in the leachate after 70 d reached 255 micro-g/d. Fumaric, malic, malonic, oxalic, and succinic acids were measured as components of the root exudates.

  1. Optimization of culture conditions to obtain maximal growth of penicillin-resistant Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Rodriguez Carlos A

    2005-06-01

    Full Text Available Abstract Background Streptococcus pneumoniae, particularly penicillin-resistant strains (PRSP, constitute one of the most important causes of serious infections worldwide. It is a fastidious microorganism with exquisite nutritional and environmental requirements to grow, a characteristic that prevents the development of useful animal models to study the biology of the microorganism. This study was designed to determine optimal conditions for culture and growth of PRSP. Results We developed a simple and reproducible method for culture of diverse strains of PRSP representing several invasive serotypes of clinical and epidemiological importance in Colombia. Application of this 3-step culture protocol consistently produced more than 9 log10 CFU/ml of viable cells in the middle part of the logarithmic phase of their growth curve. Conclusion A controlled inoculum size grown in 3 successive steps in supplemented agar and broth under 5% CO2 atmosphere, with pH adjustment and specific incubation times, allowed production of great numbers of PRSP without untimely activation of autolysis mechanisms.

  2. Establishment and culture optimization of a new type of pituitary immortalized cell line

    Energy Technology Data Exchange (ETDEWEB)

    Kokubu, Yuko [Graduate School of Life and Environmental Sciences, The University of Tsukuba, Tsukuba, Ibaraki 305-8562 (Japan); Asashima, Makoto [Graduate School of Life and Environmental Sciences, The University of Tsukuba, Tsukuba, Ibaraki 305-8562 (Japan); Life Science Center of TARA, The University of Tsukuba, Ibaraki-ken 305-8577 (Japan); Kurisaki, Akira, E-mail: akikuri@hotmail.com [Graduate School of Life and Environmental Sciences, The University of Tsukuba, Tsukuba, Ibaraki 305-8562 (Japan); Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562 (Japan)

    2015-08-07

    The pituitary gland is a center of the endocrine system that controls homeostasis in an organism by secreting various hormones. The glandular anterior pituitary consists of five different cell types, each expressing specific hormones. However, their regulation and the appropriate conditions for their in vitro culture are not well defined. Here, we report the immortalization of mouse pituitary cells by introducing TERT, E6, and E7 transgenes. The immortalized cell lines mainly expressed a thyrotroph-specific thyroid stimulating hormone beta (Tshb). After optimization of the culture conditions, these immortalized cells proliferated and maintained morphological characteristics similar to those of primary pituitary cells under sphere culture conditions in DMEM/F12 medium supplemented with N2, B27, basic FGF, and EGF. These cell lines responded to PKA or PKC pathway activators and induced the expression of Tshb mRNA. Moreover, transplantation of the immortalized cell line into subcutaneous regions and kidney capsules of mice further increased Tshb expression. These results suggest that immortalization of pituitary cells with TERT, E6, and E7 transgenes is a useful method for generating proliferating cells for the in vitro analysis of pituitary regulatory mechanisms. - Highlights: • Mouse pituitary cell lines were immortalized by introducing TERT, E6, and E7. • The immortalized cell lines mainly expressed thyroid stimulating hormone beta. • The cell lines responded to PKA or PKC pathway activators, and induced Tshb.

  3. Optimization of culture media for enhancing gamma-linolenic acid production by Mucor hiemalis

    Directory of Open Access Journals (Sweden)

    Mina Mohammadi Nasr

    2016-03-01

    Full Text Available Introduction: g-linolenic acid is an essential fatty acid in human nutrition. In the present study, production of g-linolenic acid by Mucor hiemalis PTCC 5292 was evaluated in submerged fermentation. Materials and methods: The fermentation variables were chosen according to the fractional factorial design and further optimized via full factorial method. Four significant variables, glucose, peptone, ammonium nitrate and pH were selected for the optimization studies. The design consisted of total 16 runs consisting of runs at two levels for each factor with three replications of the center points. Results: The analysis of variance and three-dimensional response surface plot of effects indicated that variables were regarded to be significant for production of g-linolenic acid by Mucor hiemalis. Results indicated that fermentation at the optimum conditions (100 g/l glucose concentration; 1 g/l peptone; 1 g/l ammonium nitrate, and pH of 4.5 enhanced the g-linolenic acid production up to 709 mg/l. Discussion and conclusion: The results of this study indicated that higher g-linolenic acid yield can be achieved in a simple medium at high glucose and ammonium nitrate, low peptone concentrations and acidic pH by Mucor hiemalis PTCC 5292. This simple and low cost optimization condition of culture media can be applied for g-linolenic acid production at higher scale for pharmaceutical and nutritional industries. 

  4. Reversed-phase dispersive liquid-liquid microextraction with multivariate optimization for sensitive HPLC determination of tyrosol and hydroxytyrosol in olive oil.

    Science.gov (United States)

    Hashemi, Payman; Nazari Serenjeh, Fariba; Ghiasvand, Ali Reza

    2011-01-01

    A reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) method coupled to HPLC was developed for the extraction of hydroxytyrosol (HTy) and tyrosol (Ty) from virgin olive oil. In this first application of the RP-DLLME method to non-polar samples, the phenolic compounds were directly extracted into an aqueous micro-drop, which could be injected into a chromatography column without any further pretreatment. A glass test tube with lengthened conical bottom was fitted inside a centrifuge tube in this work for more efficient withdrawal of the sedimented phase with a microsyringe. The volumes of water and ethyl acetate, the pH of water and the centrifuge time as four effective parameters on the extraction were optimized by a central composite design (response surface) method. Five replicated analyses under the optimized conditions (i.e., 0.2 mL ethyl acetate as disperser and 100 µL water at pH 11 as the extraction solvent) resulted in recoveries of 104.3 and 97.6%, and relative standard deviations of 5.75 and 4.57 for HTy and Ty, respectively. The detection limit of the method (3σ) was 0.043 mg L(-1) for HTy and 0.032 mg L(-1) for Ty. The method was successfully applied to the determination of HTy and Ty in five olive oil samples.

  5. Simultaneous optimization of variables influencing selectivity and elution strength in micellar liquid chromatography. Effect of organic modifier and micelle concentration.

    Science.gov (United States)

    Strasters, J K; Breyer, E D; Rodgers, A H; Khaledi, M G

    1990-07-06

    Previously, the simultaneous enhancement of separation selectivity with elution strength was reported in micellar liquid chromatography (MLC) using the hybrid eluents of water-organic solvent-micelles. The practical implication of this phenomenon is that better separations can be achieved in shorter analysis times by using the hybrid eluents. Since both micelle concentration and volume fraction of organic modifier influence selectivity and solvent strength, only an investigation of the effects of a simultaneous variation of these parameters will disclose the full separation capability of the method, i.e. the commonly used sequential solvent optimization approach of adjusting the solvent strength first and then improving selectivity in reversed-phase liquid chromatography is inefficient for the case of MLC with the hybrid eluents. This is illustrated in this paper with two examples: the optimization of the selectivity in the separation of a mixture of phenols and the optimization of a resolution-based criterion determined for the separation of a number of amino acids and small peptides. The large number of variables involved in the separation process in MLC necessitates a structured approach in the development of practical applications of this technique. A regular change in retention behavior is observed with the variation of the surfactant concentration and the concentration of organic modifier, which enables a successful prediction of retention times. Consequently interpretive optimization strategies such as the interative regression method are applicable.

  6. Ionic Liquids as Electrolytes for Electrochemical Double-Layer Capacitors: Structures that Optimize Specific Energy.

    Science.gov (United States)

    Mousavi, Maral P S; Wilson, Benjamin E; Kashefolgheta, Sadra; Anderson, Evan L; He, Siyao; Bühlmann, Philippe; Stein, Andreas

    2016-02-10

    Key parameters that influence the specific energy of electrochemical double-layer capacitors (EDLCs) are the double-layer capacitance and the operating potential of the cell. The operating potential of the cell is generally limited by the electrochemical window of the electrolyte solution, that is, the range of applied voltages within which the electrolyte or solvent is not reduced or oxidized. Ionic liquids are of interest as electrolytes for EDLCs because they offer relatively wide potential windows. Here, we provide a systematic study of the influence of the physical properties of ionic liquid electrolytes on the electrochemical stability and electrochemical performance (double-layer capacitance, specific energy) of EDLCs that employ a mesoporous carbon model electrode with uniform, highly interconnected mesopores (3DOm carbon). Several ionic liquids with structurally diverse anions (tetrafluoroborate, trifluoromethanesulfonate, trifluoromethanesulfonimide) and cations (imidazolium, ammonium, pyridinium, piperidinium, and pyrrolidinium) were investigated. We show that the cation size has a significant effect on the electrolyte viscosity and conductivity, as well as the capacitance of EDLCs. Imidazolium- and pyridinium-based ionic liquids provide the highest cell capacitance, and ammonium-based ionic liquids offer potential windows much larger than imidazolium and pyridinium ionic liquids. Increasing the chain length of the alkyl substituents in 1-alkyl-3-methylimidazolium trifluoromethanesulfonimide does not widen the potential window of the ionic liquid. We identified the ionic liquids that maximize the specific energies of EDLCs through the combined effects of their potential windows and the double-layer capacitance. The highest specific energies are obtained with ionic liquid electrolytes that possess moderate electrochemical stability, small ionic volumes, low viscosity, and hence high conductivity, the best performing ionic liquid tested being 1-ethyl-3

  7. Optimization strategies for separation of sulfadiazines using Box-Behnken design by liquid chromatography and capillary electrophoresis

    Institute of Scientific and Technical Information of China (English)

    GONG Wen-jun; ZHANG Yu-ping; ZHANG Yi-Jun; XU Guang-ri; WEI Xin-jun; LEE Kwang-pill

    2007-01-01

    Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35 ℃ and 1.0 mL/min, respectively.Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.

  8. Effect of liquid flow on culture of red beet hairy roots in single column reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hitaka, Y.; Kino-oka, M.; Taya, M.; Tone, S. [Osaka University, Osaka (Japan). Department of Chemical Science and Engineering, Graduate School of Engineering Science

    1997-12-01

    The influence of liquid flow on the growth of red beet hairy roots is investigated by using a single column reactor operated at 25degC under a fixed value of superficial velocity of medium. In the cultures of the hairy roots for 172 - 190 h, average growth rates of 2.8 times 10{sup -2}, 1.6 times 10{sup -2} and 0.98 times 10{sup -2} kg/(m{sup 3}{center_dot}h) are obtained at superficial velocities of 4.2 times 10{sup -3}, 7.8 times 10{sup -3} and 11.1 times 10{sup -3} m/s, respectively. Using the packed column with the hairy roots at void fractions of 0.49 to 0.71, it is found that pressure drop through the root bed increases with an increase in superficial velocity of medium elevated up to about 14 times 10{sup -3} m/s. The effective diameter of the hairy roots is estimated at 1.5 times 10{sup -4}m, considering the root hairs found on the surfaces of the main roots. Pressure drop through the root bed in the column can be correlated with superficial velocity of the medium by using an extended Ergun`s equation expressed in terms of effective diameter of the hairy roots and void fraction in the bed. When the hairy roots are kept for 50 h in the column under pressure drop values of 8.4 times 10{sup 3} to 3.1 times 10{sup 4} Pa/m, the reduction in viability of growing points at the hairy root tips is observed with increasing pressure drop in the range. 18 refs., 7 figs., 1 tab.

  9. Production of microsclerotia by Brazilian strains of Metarhizium spp. using submerged liquid culture fermentation.

    Science.gov (United States)

    Mascarin, Gabriel Moura; Kobori, Nilce Naomi; de Jesus Vital, Rayan Carlos; Jackson, Mark Alan; Quintela, Eliane Dias

    2014-05-01

    We investigated the potential production and desiccation tolerance of microsclerotia (MS) by Brazilian strains of Metarhizium anisopliae (Ma), M. acridum (Mc) and M. robertsii (Mr). These fungi were grown in a liquid medium containing 16 g carbon l⁻¹ with a carbon:nitrogen ratio of 50:1. One hundred milliliters cultures were grown in 250 ml Erlenmeyer flasks in a rotary incubator shaker at 28 °C and 200 rpm for 5 days. Five-day-old MS were harvested, mixed with diatomaceous earth (DE) and air-dried for 2 days at 30 °C. The air-dried MS-DE granular preparations were milled by mortar + pestle and stored in centrifuged tubes at either 26 or -20 °C. Desiccation tolerance and conidia production were assessed for dried MS granules by measuring hyphal germination after incubation for 2 days on water agar plates at 26 °C and for conidia production following 7 days incubation. Yields of MS by all strains of Metarhizium were 6.1-7.3 × 10⁶ l⁻¹ after 3 days growth with maximum MS yields (0.7-1.1 × 10⁷ l⁻¹) after 5 days growth. No differences in biomass accumulation were observed after 3 days growth, whereas Ma-CG168 showed the highest biomass accumulation after 5 days growth. Dried MS-DE preparations of all fungal strains were equally tolerant to desiccation (≥93 % germination) and the highest conidia production was obtained by MS granules of Mc-CG423 (4 × 10⁹ conidia g⁻¹). All MS granules showed similar stability after storage at either 26 or -20 °C for 3.5 months.

  10. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    Science.gov (United States)

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices.

  11. LC-MS metabolic profiling of Arabidopsis thaliana plant leaves and cell cultures: optimization of pre-LC-MS procedure parameters.

    Science.gov (United States)

    t'Kindt, Ruben; De Veylder, Lieven; Storme, Michael; Deforce, Dieter; Van Bocxlaer, Jan

    2008-08-01

    This study treats the optimization of methods for homogenizing Arabidopsis thaliana plant leaves as well as cell cultures, and extracting their metabolites for metabolomics analysis by conventional liquid chromatography electrospray ionization mass spectrometry (LC-ESI/MS). Absolute recovery, process efficiency and procedure repeatability have been compared between different pre-LC-MS homogenization/extraction procedures through the use of samples fortified before extraction with a range of representative metabolites. Hereby, the magnitude of the matrix effect observed in the ensuing LC-MS based metabolomics analysis was evaluated. Based on relative recovery and repeatability of key metabolites, comprehensiveness of extraction (number of m/z-retention time pairs) and clean-up potential of the approach (minimum matrix effects), the most appropriate sample pre-treatment was adopted. It combines liquid nitrogen homogenization for plant leaves with thermomixer based extraction using MeOH/H(2)O 80/20. As such, an efficient and highly reproducible LC-MS plant metabolomics set-up is achieved, as illustrated by the obtained results for both LC-MS (8.88%+/-5.16 versus 7.05%+/-4.45) and technical variability (12.53%+/-11.21 versus 9.31%+/-6.65) data in a comparative investigation of A. thaliana plant leaves and cell cultures, respectively.

  12. Optimization of Differential Display of Prokaryotic mRNA: Application to Pure Culture and Soil Microcosms

    Science.gov (United States)

    Fleming, James T.; Yao, Wen-Hsiang; Sayler, Gary S.

    1998-01-01

    The differential display (DD) technique, which is widely used almost exclusively for eukaryotic gene discovery, was optimized to detect differential mRNA transcription from both pure-culture and soil-derived bacterial RNA. A model system which included toluene induction of todC1 in Pseudomonas putida F1 was used to optimize the procedure. At 24-h tod induction was determined to be approximately 8 × 107 transcripts/μg or 0.08% of the total mRNA. The primer concentration, primer length, annealing temperature, and template, deoxynucleoside triphosphate, and MgCl2 concentrations were varied to optimize amplification of a todC1 fragment. The limit of detection of todC1 by DD was found to be 0.015 ng of total RNA template or approximately 103 transcripts. Once optimized, a todC1C2 gene fragment from P. putida F1 RNA was detected by using an arbitrary primer for the reverse transcriptase step in conjunction with the same arbitrary primer and a Shine-Dalgarno primer in the PCR. To verify the results, an arbitrary primer was used to detect recovery of a new salicylate-inducible naphthalene dioxygenase in Burkholderia cepacia JS150. The method was then used to detect mRNA induction in both inoculated and uninoculated toluene-induced soil microcosms. Several putative differentially expressed partial gene sequences obtained from the uninoculated microcosms were examined, and one novel fragment was found to be differentially expressed. PMID:9758787

  13. Optimization process condition for deacidification of palm oil by liquid-liquid extraction using NADES (Natural Deep Eutectic Solvent)

    Science.gov (United States)

    Israyandi, Zahrina, Ida; Mulia, Kamarza

    2017-03-01

    One of many steps in palm oil refining process is deacidification which aims to separate free fatty acids and other compounds from the oil. The deacidification process was using a green solvent, known as NADES, that consisted of betaine monohydrate and propionic acid at molar ratio of 1:8. In this study, the process conditions were optimized using the response surface method (RSM) through central composite design in order to predict the maximum distribution coefficient of palmitic acid. The obtained regression equation of the basic model for optimization was: y = 0.717 + 0.003x1 + 0.043 x2 + 0.148x3 - 0.005 x1x1 - 0.030 x2x2 + 0.047 x3x3 - 0.008 x1x2 + 0.008 x1x3 + 0.033 x2x3. The independent variables are x1 ≡ temperature (40, 60, 80 °C), x2≡ amount of palmitic acid in the palm oil (2, 5, 8 %) and x3 ≡ mass ratios of oil to NADES (1:2, 1:1, 2:1). The optimum process condition found was temperature of 62.3°C, palmitic acid content of 8%, and NADES to palm oil mass ratio of 1:2, resulting in the maximum distribution coefficient of 0.96.

  14. Nanoemulsion liquid preconcentrates for raloxifene hydrochloride: optimization and in vivo appraisal

    Directory of Open Access Journals (Sweden)

    Elsheikh MA

    2012-07-01

    Full Text Available Manal A Elsheikh,1 Yosra SR Elnaggar,1 Eman Y Gohar,2 Ossama Y Abdallah11Department of Pharmaceutics, 2Department of Pharmacology and Toxicology, Alexandria University, Alexandria, EgyptAbstract: Raloxifene hydrochloride (RLX is a selective estrogen-receptor modulator for treatment of osteoporosis and prevention of breast and endometrial cancer. By virtue of extensive presystemic clearance, RLX bioavailability is only 2%. The current study aimed to tailor and characterize RLX-loaded self-nanoemulsifying drug-delivery systems (SNEDDS using bioactive excipients affecting drug metabolism. The potential of oral nanocarriers to enhance RLX delivery to endocrine target organs was assessed in fasted and fed female Wistar rats using high-performance liquid chromatography. RLX was loaded in the dissolved and dispersed status in the alkalinized (A-SNEDDS and nonalkalinized (NA-SNEDDS systems, respectively. Optimization and assessment relied on solubility studies, emulsification efficiency, phase diagrams, dilution robustness, cloud point, particle size, zeta potential (ZP, polydispersity index (PDI, and transmission electron microscopy. In vitro release was assessed using dialysis bag versus dissolution cup methods. NA-SNEDDS were developed with suitable globule size (38.49 ± 4.30 nm, ZP (31.70 ± 3.58 mV, PDI (0.31 ± 0.02, and cloud point (85°C. A-SNEDDS exhibited good globule size (35 ± 2.80 nm, adequate PDI (0.28 ± 0.06, and lower ZP magnitude (-21.20 ± 3.46 mV. Transmission electron microscopy revealed spherical globules and contended data of size analysis. Release studies demonstrated a nonsignificant enhancement of RLX release from NA-SNEDDS compared to drug suspension with the lowest release shown by A-SNEDDS. A conflicting result was elucidated from in vivo trial. A significant enhancement in RLX uptake by endocrine organs was observed after nanocarrier administration compared to RLX suspension. In vivo studies reflected a poor in vitro

  15. Nanoemulsion liquid preconcentrates for raloxifene hydrochloride: optimization and in vivo appraisal.

    Science.gov (United States)

    Elsheikh, Manal A; Elnaggar, Yosra S R; Gohar, Eman Y; Abdallah, Ossama Y

    2012-01-01

    Raloxifene hydrochloride (RLX) is a selective estrogen-receptor modulator for treatment of osteoporosis and prevention of breast and endometrial cancer. By virtue of extensive presystemic clearance, RLX bioavailability is only 2%. The current study aimed to tailor and characterize RLX-loaded self-nanoemulsifying drug-delivery systems (SNEDDS) using bioactive excipients affecting drug metabolism. The potential of oral nanocarriers to enhance RLX delivery to endocrine target organs was assessed in fasted and fed female Wistar rats using high-performance liquid chromatography. RLX was loaded in the dissolved and dispersed status in the alkalinized (A-SNEDDS) and nonalkalinized (NA-SNEDDS) systems, respectively. Optimization and assessment relied on solubility studies, emulsification efficiency, phase diagrams, dilution robustness, cloud point, particle size, zeta potential (ZP), polydispersity index (PDI), and transmission electron microscopy. In vitro release was assessed using dialysis bag versus dissolution cup methods. NA-SNEDDS were developed with suitable globule size (38.49 ± 4.30 nm), ZP (31.70 ± 3.58 mV), PDI (0.31 ± 0.02), and cloud point (85°C). A-SNEDDS exhibited good globule size (35 ± 2.80 nm), adequate PDI (0.28 ± 0.06), and lower ZP magnitude (-21.20 ± 3.46 mV). Transmission electron microscopy revealed spherical globules and contended data of size analysis. Release studies demonstrated a nonsignificant enhancement of RLX release from NA-SNEDDS compared to drug suspension with the lowest release shown by A-SNEDDS. A conflicting result was elucidated from in vivo trial. A significant enhancement in RLX uptake by endocrine organs was observed after nanocarrier administration compared to RLX suspension. In vivo studies reflected a poor in vitro/in vivo correlation, recommended nanocarrier administration before meals, and did not reveal any advantage for drug loading in the solubilized form (A-SNEDDS). To conclude, NA-SNEDDS possessed superior in

  16. Liquid chromatography-mass spectrometry for metabolic footprinting of co-cultures of lactic and propionic acid bacteria

    DEFF Research Database (Denmark)

    Honore, Anders H.; Thorsen, Michael; Skov, Thomas

    2013-01-01

    Co-cultures of specific lactic and propionic acid bacteria have been shown to have an antagonistic effect against yeast and moulds in dairy systems. In studies of these co-cultures by bioassay-guided fractionation and analysis, numerous compounds have been reported to inhibit yeast and moulds...... could be a potent approach to elucidation of the mechanism. The purpose of this review is to discuss the two pre-requisites for such a study-the compound classes expected in the co-cultures, and on the basis of these, the most suitable analytical technique(s). Ultrahigh-performance liquid chromatography....... The strategy recommended in this study does not include all compound classes, and suggestions for supplementary methods are listed....

  17. Optimization of Production Medium for Mass Culture of Metarhizium anisopliae ARS 2231

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seung Woo [Korea University, Seoul (Korea); Moon, Ki Hyuk [Kyungwon University Technology Complex, Songnam (Korea); Yoon, Jeong Weon [Suwon University, Suwon (Korea)

    1999-11-01

    Chemical pesticides which have been commonly used for crop protection have many problems such as high production cost and environmental hazards. Entomogeneous fungi which attack living insects are very powerful means for microbiological insecticide. The purpose of this study is to investigate the culture conditions for mass production of Metarhizium anisopliae ARS 2231 which is a potential microbiological pesticide. The temperature and pH range for optimal cultivation were 28 deg. C and pH 5.0-7.0, respectively. For M. anisopliae ARS 2231, 3.0% (w/v) rice bran, 0.8% (w/v) hydrolyzed casein, and 0.3% (w/v) K{sub 2}HPO{sub 4} were found as the proper nutrients, considering cell mass, enzyme activities, and spore concentration. 16 refs., 10 tabs.

  18. Mixed culture optimization for marigold flower ensilage via experimental design and response surface methodology.

    Science.gov (United States)

    Navarrete-Bolaños, José Luis; Jiménez-Islas, Hugo; Botello-Alvarez, Enrique; Rico-Martínez, Ramiro

    2003-04-09

    Endogenous microorganisms isolated from the marigold flower (Tagetes erecta) were studied to understand the events taking place during its ensilage. Studies of the cellulase enzymatic activity and the ensilage process were undertaken. In both studies, the use of approximate second-order models and multiple lineal regression, within the context of an experimental mixture design using the response surface methodology as optimization strategy, determined that the microorganisms Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans are the most significant in marigold flower ensilage and exhibit high cellulase activity. A mixed culture comprised of 9.8% Flavobacterium IIb, 41% A. anitratus, and 49.2% R. nigricans used during ensilage resulted in an increased yield of total xanthophylls extracted of 24.94 g/kg of dry weight compared with 12.92 for the uninoculated control ensilage.

  19. Enhancement of botrallin and TMC-264 production in liquid culture of endophytic fungus Hyalodendriella sp. Ponipodef12 after treatments with metal ions

    Directory of Open Access Journals (Sweden)

    Haiyu Luo

    2016-11-01

    Conclusion: The results indicated that the enhancement of botrallin and TMC-264 accumulation in liquid culture of the endophytic fungus Hyalodendriella sp. Ponipodef12 by the metal ions and their combination should be an effective strategy.

  20. Optimization of the liquid fermentation condition of Bacillus atrophaeus%萎缩芽孢杆菌液体发酵条件的优化

    Institute of Scientific and Technical Information of China (English)

    闫洁; 宁丹妮; 梁宇; 周洪友

    2015-01-01

    To obtain high density bacterial fertilizer, the liquid fermentation conditions of Bacillus atrophaeus were optimized by single factor experiments. The results showed that the optimal culture conditions were temperature of 32℃, initial pH of 7.0, medium volume of 50 mL/250 mL flask, inoculation amount of 2% and incubation time of 24 h. The results could provide basic data for production of Bacillus atrophaeus bacterial fertilizer for agricultural application.%为了获得高效的细菌菌剂,采用单因素试验对萎缩芽孢杆菌XT1-4的液体发酵条件进行优化,研究结果表明:该菌株的最佳培养条件为:发酵温度32℃、初始pH值7.0、装液量50 mL/250 mL三角瓶、接种量2%、培养时间24 h。研究结果为工业生产萎缩芽孢杆菌菌剂提供了基础数据。

  1. A simple colony-formation assay in liquid medium, termed 'tadpoling', provides a sensitive measure of Saccharomyces cerevisiae culture viability.

    Science.gov (United States)

    Welch, Aaron Z; Koshland, Douglas E

    2013-12-01

    Here we describe the first high-throughput amenable method of quantifying Saccharomyces cerevisiae culture viability. Current high-throughput methods of assessing yeast cell viability, such as flow cytometry and SGA analysis, do not measure the percentage viability of a culture but instead measure cell vitality or colony fitness, respectively. We developed a method, called tadpoling, to quantify the percentage viability of a yeast culture, with the ability to detect as few as one viable cell amongst ~10(8) dead cells. The most important feature of this assay is the exploitation of yeast colony formation in liquid medium. Utilizing a microtiter dish, we are able to observe a range of viability of 100% to 0.0001%. Comparison of tadpoling to the traditional plating method to measure yeast culture viability reveals that, for the majority of Saccharomyces species analyzed there is no significant difference between the two methods. In comparison to flow cytometry using propidium iodide, the high-throughput method of measuring yeast culture viability, tadpoling is much more accurate at culture viabilities viability.

  2. Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems

    Science.gov (United States)

    Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

  3. Optimizing NTS-polyplex as a tool for gene transfer to cultured dopamine neurons.

    Science.gov (United States)

    Hernandez-Baltazar, Daniel; Martinez-Fong, Daniel; Trudeau, Louis-Eric

    2012-01-01

    The study of signal transduction in dopamine (DA)-containing neurons as well as the development of new therapeutic approaches for Parkinson's disease requires the selective expression of transgenes in such neurons. Here we describe optimization of the use of the NTS-polyplex, a gene carrier system taking advantage of neurotensin receptor internalization, to transfect mouse DA neurons in primary culture. The plasmids DsRed2 (4.7 kbp) and VGLUT2-Venus (11 kbp) were used to compare the ability of this carrier system to transfect plasmids of different sizes. We examined the impact of age of the neurons (1, 3, 5 and 8 days after seeding), of culture media used during the transfection (Neurobasal with B27 vs. conditioned medium) and of three molar ratios of plasmid DNA to carrier. While the NTS-polyplex successfully transfected both plasmids in a control N1E-115 cell line, only the pDsRed2 plasmid could be transfected in primary cultured DA neurons. We achieved 20% transfection efficiency of pDsRed2 in DA neurons, with 80% cell viability. The transfection was demonstrated pharmacologically to be dependent on activation of neurotensin receptors and to be selective for DA neurons. The presence of conditioned medium for transfection was found to be required to insure cell viability. Highest transfection efficiency was achieved in the most mature neurons. In contrast, transfection with the VGLUT2-Venus plasmid produced cell damage, most likely due to the high molar ratios required, as evidenced by a 15% cell viability of DA neurons at the three molar ratios tested (1:36, 1:39 and 1:42). We conclude that, when used at molar ratios lower than 1:33, the NTS-polyplex can selectively transfect mature cultured DA neurons with only low levels of toxicity. Our results provide evidence that the NTS-polyplex has good potential for targeted gene delivery in cultured DA neurons, an in vitro system of great use for the screening of new therapeutic approaches for Parkinson's disease.

  4. Development and optimization of a metabolomic method for analysis of adherent cell cultures.

    Science.gov (United States)

    Danielsson, Anders P H; Moritz, Thomas; Mulder, Hindrik; Spégel, Peter

    2010-09-01

    In this investigation, a gas chromatography/mass spectrometry (GC/MS)-based metabolomic protocol for adherent cell cultures was developed using statistical design of experiments. Cell disruption, metabolite extraction, and the GC/MS settings were optimized aiming at a gentle, unbiased, sensitive, and high-throughput metabolomic protocol. Due to the heterogeneity of the metabolome and the inherent selectivity of all analytical techniques, development of unbiased protocols is highly complex. Changing one parameter of the protocol may change the response of many groups of metabolites. In this investigation, statistical design of experiments and multivariate analysis also allowed such interaction effects to be taken into account. The protocol was validated with respect to linear range, precision, and limit of detection in a clonal rat insulinoma cell line (INS-1 832/13). The protocol allowed high-throughput profiling of metabolites covering the major metabolic pathways. The majority of metabolites displayed a linear range from a single well in a 96-well plate up to a 10 cm culture dish. The method allowed a total of 47 analyses to be performed in 24h.

  5. Optimized culture condition for enhancing lytic performance of waste activated sludge by Geobacillus sp. G1.

    Science.gov (United States)

    Yang, Chunxue; Zhou, Aijuan; Hou, Yanan; Zhang, Xu; Guo, Zechong; Wang, Aijie; Liu, Wenzong

    2014-01-01

    Hydrolysis is known as the rate-limiting step during waste activated sludge (WAS) digestion. The optimization of the culture conditions of Geobacillus sp. G1 for enhancing WAS hydrolysis was conducted in this study with uniform design and response surface methodology. Taking the lysis rate of Escherichia coli as the response, the Plackett-Burman design was used to screen the most important variables. Experimental results showed that the maximum predicted lysis rate of E. coli was 50.9% for 4 h treatment time with concentrations of skim milk, NaCl and NH4SO4 at 10.78, 4.36 and 11.28 g/L, respectively. The optimized dosage ratio of Geobacillus sp. G1 to WAS was 35%:65% (VG1:VWAS). Under this condition, soluble protein was increased to 695 mg chemical oxygen demand (COD)/L, which was 5.0 times higher than that obtained in the control (140 mg COD/L). The corresponding protease activity reached 1.1 Eu/mL. Scanning electron microscopy showed that abundant cells were apparently lysed with treatment of Geobacillus sp. G1.

  6. Metabolomic approach to optimizing and evaluating antibiotic treatment in the axenic culture of cyanobacterium Nostoc flagelliforme.

    Science.gov (United States)

    Han, Pei-pei; Jia, Shi-ru; Sun, Ying; Tan, Zhi-lei; Zhong, Cheng; Dai, Yu-jie; Tan, Ning; Shen, Shi-gang

    2014-09-01

    The application of antibiotic treatment with assistance of metabolomic approach in axenic isolation of cyanobacterium Nostoc flagelliforme was investigated. Seven antibiotics were tested at 1-100 mg L(-1), and order of tolerance of N. flagelliforme cells was obtained as kanamycin > ampicillin, tetracycline > chloromycetin, gentamicin > spectinomycin > streptomycin. Four antibiotics were selected based on differences in antibiotic sensitivity of N. flagelliforme and associated bacteria, and their effects on N. flagelliforme cells including the changes of metabolic activity with antibiotics and the metabolic recovery after removal were assessed by a metabolomic approach based on gas chromatography-mass spectrometry combined with multivariate analysis. The results showed that antibiotic treatment had affected cell metabolism as antibiotics treated cells were metabolically distinct from control cells, but the metabolic activity would be recovered via eliminating antibiotics and the sequence of metabolic recovery time needed was spectinomycin, gentamicin > ampicillin > kanamycin. The procedures of antibiotic treatment have been accordingly optimized as a consecutive treatment starting with spectinomycin, then gentamicin, ampicillin and lastly kanamycin, and proved to be highly effective in eliminating the bacteria as examined by agar plating method and light microscope examination. Our work presented a strategy to obtain axenic culture of N. flagelliforme and provided a method for evaluating and optimizing cyanobacteria purification process through diagnosing target species cellular state.

  7. Optimizing Immobilized Enzyme Performance in Cell-Free Environments to Produce Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Belfort, Georges [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering; Grimaldi, Joseph J. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering

    2015-01-27

    Limitations on biofuel production using cell culture (Escherichia coli, Clostridium, Saccharomyces cerevisiae, brown microalgae, blue-green algae and others) include low product (alcohol) concentrations (≤0.2 vol%) due to feedback inhibition, instability of cells, and lack of economical product recovery processes. To overcome these challenges, an alternate simplified biofuel production scheme was tested based on a cell-free immobilized enzyme system. Using this cell free system, we were able to obtain about 2.6 times higher concentrations of iso-butanol using our non-optimized system as compared with live cell systems. This process involved two steps: (i) converts acid to aldehyde using keto-acid decarboxylase (KdcA), and (ii) produces alcohol from aldehyde using alcohol dehydrogenase (ADH) with a cofactor (NADH) conversion from inexpensive formate using a third enzyme, formate dehydrogenase (FDH). To increase stability and conversion efficiency with easy separations, the first two enzymes were immobilized onto methacrylate resin. Fusion proteins of labile KdcA (fKdcA) were expressed to stabilize the covalently immobilized KdcA. Covalently immobilized ADH exhibited long-term stability and efficient conversion of aldehyde to alcohol over multiple batch cycles without fusions. High conversion rates and low protein leaching were achieved by covalent immobilization of enzymes on methacrylate resin. The complete reaction scheme was demonstrated by immobilizing both ADH and fKdcA and using FDH free in solution. The new system without in situ removal of isobutanol achieved a 55% conversion of ketoisovaleric acid to isobutanol at a concentration of 0.5 % (v/v). Further increases in titer will require continuous removal of the isobutanol using our novel brush membrane system that exhibits a 1.5 fold increase in the separation factor of isobutanol from water versus that obtained for commercial silicone rubber membranes. These bio-inspired brush membranes are based on the

  8. Defining an optimal surface chemistry for pluripotent stem cell culture in 2D and 3D

    Science.gov (United States)

    Zonca, Michael R., Jr.

    new avenue for stem cell culture and maintenance using an optimal organic-based chemistry.

  9. On-line optimal control for fed-batch culture of baker's yeast production

    Energy Technology Data Exchange (ETDEWEB)

    Wu, W.T.; Chen, K.C.; Chiou, H.W.

    1985-05-01

    A method of on-line optimal control for fed-batch culture of bakers yeast production is proposed. The feed rate is taken as the control variable. The specific growth rate of the yeast is the output variable and is determined from the balance equation of oxygen. A moving model is obtained by using the data from the feed rate and the specific growth rate. Based on the moving model, an optimal feed rate for fed-batch culture is then achieved. 11 references.

  10. Experimental and computational optimization of an Escherichia coli co-culture for the efficient production of flavonoids.

    Science.gov (United States)

    Jones, J Andrew; Vernacchio, Victoria R; Sinkoe, Andrew L; Collins, Shannon M; Ibrahim, Mohammad H A; Lachance, Daniel M; Hahn, Juergen; Koffas, Mattheos A G

    2016-05-01

    Metabolic engineering and synthetic biology have enabled the use of microbial production platforms for the renewable production of many high-value natural products. Titers and yields, however, are often too low to result in commercially viable processes. Microbial co-cultures have the ability to distribute metabolic burden and allow for modular specific optimization in a way that is not possible through traditional monoculture fermentation methods. Here, we present an Escherichia coli co-culture for the efficient production of flavonoids in vivo, resulting in a 970-fold improvement in titer of flavan-3-ols over previously published monoculture production. To accomplish this improvement in titer, factors such as strain compatibility, carbon source, temperature, induction point, and inoculation ratio were initially optimized. The development of an empirical scaled-Gaussian model based on the initial optimization data was then implemented to predict the optimum point for the system. Experimental verification of the model predictions resulted in a 65% improvement in titer, to 40.7±0.1mg/L flavan-3-ols, over the previous optimum. Overall, this study demonstrates the first application of the co-culture production of flavonoids, the most in-depth co-culture optimization to date, and the first application of empirical systems modeling for improvement of titers from a co-culture system.

  11. Application and optimization of microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for sensitive determination of polyamines in turkey breast meat samples.

    Science.gov (United States)

    Bashiry, Moein; Mohammadi, Abdorreza; Hosseini, Hedayat; Kamankesh, Marzieh; Aeenehvand, Saeed; Mohammadi, Zaniar

    2016-01-01

    A novel method based on microwave-assisted extraction and dispersive liquid-liquid microextraction (MAE-DLLME) followed by high-performance liquid chromatography (HPLC) was developed for the determination of three polyamines from turkey breast meat samples. Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the effective factors in DLLME process. The optimum microextraction efficiency was obtained under optimized conditions. The calibration graphs of the proposed method were linear in the range of 20-200 ng g(-1), with the coefficient determination (R(2)) higher than 0.9914. The relative standard deviations were 6.72-7.30% (n = 7). The limits of detection were in the range of 0.8-1.4 ng g(-1). The recoveries of these compounds in spiked turkey breast meat samples were from 95% to 105%. The increased sensitivity in using the MAE-DLLME-HPLC-UV has been demonstrated. Compared with previous methods, the proposed method is an accurate, rapid and reliable sample-pretreatment method.

  12. Automated Gravimetric Calibration to Optimize the Accuracy and Precision of TECAN Freedom EVO Liquid Handler.

    Science.gov (United States)

    Bessemans, Laurent; Jully, Vanessa; de Raikem, Caroline; Albanese, Mathieu; Moniotte, Nicolas; Silversmet, Pascal; Lemoine, Dominique

    2016-10-01

    High-throughput screening technologies are increasingly integrated into the formulation development process of biopharmaceuticals. The performance of liquid handling systems is dependent on the ability to deliver accurate and precise volumes of specific reagents to ensure process quality. We have developed an automated gravimetric calibration procedure to adjust the accuracy and evaluate the precision of the TECAN Freedom EVO liquid handling system. Volumes from 3 to 900 µL using calibrated syringes and fixed tips were evaluated with various solutions, including aluminum hydroxide and phosphate adjuvants, β-casein, sucrose, sodium chloride, and phosphate-buffered saline. The methodology to set up liquid class pipetting parameters for each solution was to split the process in three steps: (1) screening of predefined liquid class, including different pipetting parameters; (2) adjustment of accuracy parameters based on a calibration curve; and (3) confirmation of the adjustment. The run of appropriate pipetting scripts, data acquisition, and reports until the creation of a new liquid class in EVOware was fully automated. The calibration and confirmation of the robotic system was simple, efficient, and precise and could accelerate data acquisition for a wide range of biopharmaceutical applications.

  13. Structural Equation Modeling Applied to the Reaction to Stock Dividends and Stock Splits: integrating signaling, liquidity and optimal price level

    Directory of Open Access Journals (Sweden)

    Kelmara Mendes Vieira

    2011-03-01

    Full Text Available This work develops a hybrid model of structural equations able to take simultaneously the hypotheses of signaling, liquidity, and optimal price level to explain the reaction to the stock dividends and stock splits. In the measurement model four constructs were defined: trading activity, spread, size, and price. The structural model defines extant relations from the proposition of 22 sub-hypotheses. A sample of 321 splits performed in the Brazilian market between 1990 and 2004 was used for assessing the model. Confirmatory factor analysis revealed the validity and coherence of the four constructs. The structural model confirmed 9 original sub-hypotheses.

  14. Unusual Metallic Conductivity of Underdoped and Optimally Doped Cuprates: Evidence for Competing Fermi-Liquid and Pairing Pseudogap Effects

    OpenAIRE

    Dzhumanov, S.; Dushanov, E.

    2004-01-01

    We propose a possible scenario for the new metallic conductivity of underdoped and optimally doped cuprates. Charge carriers are assumed to be large polarons which form a Fermi-liquid and Cooper-like pairs below a crossover tempurature $T^{\\ast}$. We use the Boltzmann equation to calculate the conductivity of self-trapped carriers and the resistivity $\\rho$ as a function of temperature and doping for different cuprates. We show that various anomalies in $\\rho(T)$ below $T^{\\ast}$ are caused b...

  15. Identification of a New Marine Bacterial Strain SD8 and Optimization of Its Culture Conditions for Producing Alkaline Protease.

    Science.gov (United States)

    Cui, Hongxia; Yang, Muyang; Wang, Liping; Xian, Cory J

    2015-01-01

    While much attention has been given to marine microorganisms for production of enzymes, which in general are relatively more stable and active compared to those from plants and animals, studies on alkaline protease production from marine microorganisms have been very limited. In the present study, the alkaline protease producing marine bacterial strain SD8 isolated from sea muds in the Geziwo Qinhuangdao sea area of China was characterized and its optimal culture conditions were investigated. Strain SD8 was initially classified to belong to genus Pseudomonas by morphological, physiological and biochemical characterizations, and then through 16S rDNA sequence it was identified to be likely Pseudomonas hibiscicola. In addition, the culture mediums, carbon sources and culture conditions of strain SD8 were optimized for maximum production of alkaline protease. Optimum enzyme production (236U/mL when cultured bacteria being at 0.75 mg dry weight/mL fermentation broth) was obtained when the isolate at a 3% inoculum size was grown in LB medium at 20 mL medium/100mL Erlenmeyer flask for 48h culture at 30°C with an initial of pH 7.5. This was the first report of strain Pseudomonas hibiscicola secreting alkaline protease, and the data for its optimal cultural conditions for alkaline protease production has laid a foundation for future exploration for the potential use of SD8 strain for alkaline protease production.

  16. Medium Optimization and Submerged Culture for Cenococcum geophilum Fr%土生空团菌培养基优化与摇瓶培养

    Institute of Scientific and Technical Information of China (English)

    薛丽宁; 曹凤娟; 赵慧英; 姚庆智; 闫伟

    2013-01-01

    Based on the results of the single-factor tests, the medium components of four strains of Cg (CgSO1, CgSB2, CgO5 and SPOP2) were optimized by the orthogonal tests. The results showed that the four strains of Cg required different medium components and different carbon sources, nitrogen sources, microelements, mineral salt components and vitamins. The best carbon source and nitrogen source for CgSOl, CgSB2 and CgO5 were glucose + wort and beef extract while SPOP2 were wort and ammonium tartrate. The appropriate amount of microelements, mineral salts and Vitamin Bl enhanced the growth of CgSOl, CgSB2, CgO5 and SPOP2. The results of the optimized medium by plate culture could be used in liquid culture and the biomass of the four strains in liquid culture were 13.2, 12.4, 18.9 and 15.1 g/L, respectively, which all met the requirement of liquid fermentation production. Fig 1, Tab 6, Ref 17%在单因素试验的基础上,通过正交试验对CgSO1、CgSB2、CgO5和SPOP2这4株土生空团菌[Cenococcum geophilum Fr.(Cg)]的培养基配方分别进行了优化.结果发现,来源不同的Cg菌株对培养基组分需求存在一定差异,碳氮源、微量元素、无机盐以及维生素都不相同,CgSO1、CgSB2、CgO5对葡萄糖和麦芽汁的混合C源以及牛肉浸膏利用最好,SPOP2对麦芽汁以及酒石酸铵的利用最好,适量的微量元素、无机盐以及维生素B1会促进Cg的生长.经平板培养基优化后的培养基配方可应用到液体培养中,这4株Cg菌经液体培养后菌丝产量分别达到了13.2、12.4、18.9和15.1g/L,均可满足液体发酵的生产要求.

  17. Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production.

    Science.gov (United States)

    Geipel, Katja; Song, Xue; Socher, Maria Lisa; Kümmritz, Sibylle; Püschel, Joachim; Bley, Thomas; Ludwig-Müller, Jutta; Steingroewer, Juliane

    2014-03-01

    Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l(-1) sucrose, 0.5 mg l(-1) of the auxin 1-naphthalene acetic acid, and 0.5 mg l(-1) of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230%) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.

  18. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods

    Science.gov (United States)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-01

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (24) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL-1 with detection limit of 6.7 ng mL-1 (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n = 7, c = 50 ng mL-1). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination.

  19. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods.

    Science.gov (United States)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-25

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (2(4)) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL(-1) with detection limit of 6.7 ng mL(-1) (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n=7, c=50 ng mL(-1)). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination. Copyright © 2014. Published by Elsevier B.V.

  20. Optimization of a phase separation based magnetic-stirring salt-induced liquid-liquid microextraction method for determination of fluoroquinolones in food.

    Science.gov (United States)

    Gao, Ming; Wang, Huili; Ma, Meiping; Zhang, Yuna; Yin, Xiaohan; Dahlgren, Randy A; Du, Dongli; Wang, Xuedong

    2015-05-15

    Herein, we developed a novel integrated apparatus to perform phase separation based on magnetic-stirring, salt-induced, liquid-liquid microextraction for determination of five fluoroquinolones in animal-based foods by HPLC analysis. The novel integrated apparatus consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 791 μL of acetone solvent, 2.5 g of Na2SO4, pH 1.7, 3.0 min of stir time, and 5.5 min centrifugation. The limits of detection were 0.07-0.53 μg kg(-1) and recoveries were 91.6-105.0% for the five fluoroquinolones from milk, eggs and honey. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinolones in animal-based foods. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Optimization of dispersive liquid-phase microextraction based on solidified floating organic drop combined with high-performance liquid chromatography for the analysis of glucocorticoid residues in food.

    Science.gov (United States)

    Huang, Yuan; Zheng, Zhiqun; Huang, Liying; Yao, Hong; Wu, Xiao Shan; Li, Shaoguang; Lin, Dandan

    2017-05-10

    A rapid, simple, cost-effective dispersive liquid-phase microextraction based on solidified floating organic drop (SFOD-LPME) was developed in this study. Along with high-performance liquid chromatography, we used the developed approach to determine and enrich trace amounts of four glucocorticoids, namely, prednisone, betamethasone, dexamethasone, and cortisone acetate, in animal-derived food. We also investigated and optimized several important parameters that influenced the extraction efficiency of SFOD-LPME. These parameters include the extractant species, volumes of extraction and dispersant solvents, sodium chloride addition, sample pH, extraction time and temperature, and stirring rate. Under optimum experimental conditions, the calibration graph exhibited linearity over the range of 1.2-200.0ng/ml for the four analytes, with a reasonable linearity(r(2): 0.9990-0.9999). The enrichment factor was 142-276, and the detection limits was 0.39-0.46ng/ml (0.078-0.23μg/kg). This method was successfully applied to analyze actual food samples, and good spiked recoveries of over 81.5%-114.3% were obtained.

  2. Optimized ultrasonic assisted extraction-dispersive liquid-liquid microextraction coupled with gas chromatography for determination of essential oil of Oliveria decumbens Vent.

    Science.gov (United States)

    Sereshti, Hassan; Izadmanesh, Yahya; Samadi, Soheila

    2011-07-22

    Ultrasonic assisted extraction-dispersive liquid-liquid microextraction (UAE-DLLME) coupled with gas chromatography (GC) was applied for extraction and determination of essential oil constituents of the plant Oliveria decumbens Vent. Scanning electron microscopy (SEM) was used to see the effect of ultrasonic radiation on the extraction efficiency. By comparison with hydrodistillation, UAE-DLLME is fast, low cost, simple, efficient and consuming small amount of plant materials (∼1.0 g). The effects of various parameters such as temperature, ultrasonication time, volume of disperser and extraction solvents were investigated by a full factorial design to identify significant variables and their interactions. The results demonstrated that temperature and ultrasonication time had no considerable effect on the results. In the next step, a central composite design (CCD) was performed to obtain the optimum levels of significant parameters. The obtained optimal conditions were: 0.45 mL for disperser solvent (acetonitrile) and 94.84 μL for extraction solvent (chlorobenzene). The limits of detection (LODs), linear dynamic range and determination coefficients (R(2)) were 0.2-29 ng mL(-1), 1-2100 ng mL(-1) and 0.995-0.998, respectively. The main components of the essential oil were: thymol (47.06%), carvacrol (23.31%), gamma-terpinene (18.94%), p-cymene (8.71%), limonene (0.76%) and myristicin (0.63%).

  3. Optimization of culture conditions for the expansion of umbilical cord-derived mesenchymal stem or stromal cell-like cells using xeno-free culture conditions.

    Science.gov (United States)

    Hatlapatka, Tim; Moretti, Pierre; Lavrentieva, Antonina; Hass, Ralf; Marquardt, Nicole; Jacobs, Roland; Kasper, Cornelia

    2011-04-01

    First isolated from bone marrow, mesenchymal stem or stromal cells (MSC) were shown to be present in several postnatal and extraembryonic tissues as well as in a large variety of fetal tissues (e.g., fatty tissue, dental pulp, placenta, umbilical cord blood, and tissue). In this study, an optimized protocol for the expansion of MSC-like cells from whole umbilical cord tissue under xeno-free culture conditions is proposed. Different fetal calf sera and human serum (HS) were compared with regard to cell proliferation and MSC marker stability in long-term expansion experiments, and HS was shown to support optimal growth conditions. Additionally, the optimal concentration of HS during the cultivation was determined. With regard to cell proliferative potential, apoptosis, colony-forming unit fibroblast frequency, and cell senescence, our findings suggest that an efficient expansion of the cells is carried out best in media supplemented with 10% HS. Under our given xeno-free culture conditions, MSC-like cells were found to display in vitro immunoprivileged and immunomodulatory properties, which were assessed by co-culture and transwell culture experiments with carboxyfluorescein diacetate succinimidyl ester-labeled peripheral blood mononuclear cells. These findings may be of great value for the establishment of biotechnological protocols for the delivery of sufficient cell numbers of high quality for regenerative medicine purposes.

  4. Optimization of processing parameter for fabrication of polylactic acid/liquid natural rubber/graphene nanoplatelet by tensile properties

    Science.gov (United States)

    Shahdan, Dalila; Ahmad, Sahrim Hj.; Chen, Ruey Shan; Ali, Adilah Mat; Zailan, Farrah Diyana

    2016-11-01

    A study on processing parameter of polylactic acid (PLA) and graphene nanoplatelet (GNP) prepared via melt blending method using Haake Rheomix internal mixer. In this study liquid natural rubber (LNR) was used as compatibilizer and at the same time introducing ductile property into the nanocomposite blending. In order to determine the optimal processing parameter, nanocomposites were fabricated from PLA: LNR with ratio of 90:10, and 0.2 wt. % of graphene nanoplatelet with different mixing parameter condition; mixing temperature, rotor speed and mixing time. The optimal processing parameter was determined from the results of tensile testing. An optimum processing parameter of polymer nanocomposite was obtained at 180 °C of mixing temperature, 100 rpm of mixing speed and 14 min of mixing time. The SEM micrographs confirmed the dispersion of GNP in the PLA matrix.

  5. Optimized nested Markov chain Monte Carlo sampling: application to the liquid nitrogen Hugoniot using density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Milton Sam [Los Alamos National Laboratory; Coe, Joshua D [Los Alamos National Laboratory; Sewell, Thomas D [UNIV OF MISSOURI-COLUMBIA

    2009-01-01

    An optimized version of the Nested Markov Chain Monte Carlo sampling method is applied to the calculation of the Hugoniot for liquid nitrogen. The 'full' system of interest is calculated using density functional theory (DFT) with a 6-31 G* basis set for the configurational energies. The 'reference' system is given by a model potential fit to the anisotropic pair interaction of two nitrogen molecules from DFT calculations. The EOS is sampled in the isobaric-isothermal (NPT) ensemble with a trial move constructed from many Monte Carlo steps in the reference system. The trial move is then accepted with a probability chosen to give the full system distribution. The P's and T's of the reference and full systems are chosen separately to optimize the computational time required to produce the full system EOS. The method is numerically very efficient and predicts a Hugoniot in excellent agreement with experimental data.

  6. Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

    2015-10-01

    In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually extraction and analysis of essential oil.

  7. Novel technique for scaling up of micropropagated Ruta graveolens shoots using liquid culture systems: a step towards commercialization.

    Science.gov (United States)

    Diwan, Renuka; Malpathak, Nutan

    2008-06-01

    Wide applications of Ruta graveolens L. in pharmaceutical industry has led to increased interest in large-scale plant production, with emphasis on use of in vitro cultures. Earlier reports describe use of in vitro germinated seedlings for raising shoot cultures and not regeneration. There is only a single regeneration protocol of R. graveolens; however, it employs conventional labour intensive techniques deterring automation. The aim of present investigation was to establish a cost effective protocol for large-scale plant production. We report for the first time a one-step protocol with improved regeneration efficiency for multiple shoots induction employing liquid culture systems. Effect of polyamines (putrescine and spermine) on growth and furanocoumarin was studied. Addition of spermine enhanced the number of multiple shoots formed (2.5-fold) and reduced the time taken by half. Spermine addition resulted in 1.47-fold in furanocoumarin production. The selected shoot line, RS2 was successfully scaled up to 5L in culture vessels, with 1.53-fold increase in biomass without affecting the productivity of these cultures. This proves to be a commercially feasible alternative to bioreactors for large-scale biomass and furanocoumarin production.

  8. Liquid shoot culture of Salvia officinalis L. for micropropagation and production of antioxidant compounds; effect of triacontanol

    Directory of Open Access Journals (Sweden)

    Izabela Grzegorczyk

    2011-01-01

    Full Text Available Liquid shoot culture of Salvia officinalis L. in MS medium containing IAA (0.1 mg l-1 and BAP (0.45 mg l-1 was developed and evaluated in relation to shoot multiplication and antioxidant compound (carnosic acid, carnosol and rosmarinic acid accumulation. In the liquid medium, on average, 3 new shoots per explant (shoot tip were obtained within 3 weeks. The shoots produced 8.2±0.02 mg of diterpenoids and 31.2±0.29 mg of rosmarinic acid per gram of dry weight. Shoot proliferation and diterpenoid content increased when triacontanol (5, 10 or 20 pg l-1 was added to the liquid medium. In optimum conditions (at 20 pg l-1 TRIA almost 7 shoots were formed per explant after 3 weeks. An increase in diterpenoid production (expressed as the sum of carnosol and carnosic acid ranged from 30% to 50% and dependended on triacontanol concentration tested. The level of diterpenoids in triacontanol-treated shoots was similar to the content of compounds in commercial herbal product (dried leaves of S. officinalis (10-12 mg g-1 dry wt. Triacontanol did not increase rosmarinic acid production, but the content of the phenolic as compound in shoots grown in liquid culture (31 mg g-1 dry wt was even 24 times higher compared to samples of dried leaves of S. officinalis plants. We also demonstrated that the highest amounts of CA, Car and RA were accumulated in young, top parts of sage shoots. This observation could be useful for improving the selection of material for the extraction of natural antioxidants from S. officinalis.

  9. Glycolysis-Optimized Conditions Enhance Maintenance of Regenerative Integrity in Mouse Spermatogonial Stem Cells during Long-Term Culture

    Directory of Open Access Journals (Sweden)

    Aileen R. Helsel

    2017-05-01

    Full Text Available The application of spermatogonial stem cell (SSC transplantation for regenerating male fertility requires amplification of SSC number in vitro during which the integrity to re-establish spermatogenesis must be preserved. Conventional conditions supporting proliferation of SSCs from mouse pups have been the basis for developing methodology with adult human cells but are unrefined. We found that the integrity to regenerate spermatogenesis after transplantation declines with advancing time in primary cultures of pup SSCs and that the efficacy of deriving cultures from adult SSCs is limited with conventional conditions. To address these deficiencies, we optimized the culture environment to favor glycolysis as the primary bioenergetics process. In these conditions, regenerative integrity of pup and adult SSCs was significantly improved and the efficiency of establishing primary cultures was 100%. Collectively, these findings suggest that SSCs are primed for conditions favoring glycolytic activity, and matching culture environments to their bioenergetics is critical for maintaining functional integrity.

  10. A strategy for the systematic development of a liquid chromatographic mass spectrometric screening method for polymer electrolyte membrane degradation products using isocratic and gradient phase optimized liquid chromatography.

    Science.gov (United States)

    Zedda, M; Tuerk, J; Teutenberg, T; Peil, S; Schmidt, T C

    2009-12-18

    Within the scope of research for target and non-target LC-MS/MS analysis of membrane degradation products of polymer electrolyte membrane fuel cells, a systematic method development for the separation of structurally similar compounds was performed by phase optimized liquid chromatography. Five different stationary phases with different selectivities were used. Isocratic separation for 4-hydroxybenzoic acid, isophthalic acid, terephthalic acid, 4-hydroxybenzaldehyde and 4-formylbenzoic acid was achieved on a C18 and a Phenyl phase. Using the PRISMA model the separation efficiency was optimized. This was achieved on a serially connected mixed stationary phase composed of 30 mm C18, 150 mm Phenyl and 60 mm C30. For the LC-MS screening of unknown degradation products from polymer electrolyte membranes in the product water of a fuel cell, a solvent gradient is mandatory for less polar or later eluting compounds. By means of 4-mercaptobenzoic acid it could be shown that a solvent gradient can be applied in order to elute later eluting compounds in a short time. The adaptability of this method for the qualitative analysis by target and non-target LC-MS/MS screening has been shown by means of 4-hydroxybenzoic acid. The combination of solvent gradient and isocratic conditions makes this approach attractive for the purpose of a screening method for known and unknown analytes in a water sample.

  11. Research on Gas-liquid Flow Rate Optimization in Foam Drilling

    Science.gov (United States)

    Gao, B. K.; Sun, D. G.; Jia, Z. G.; Huang, Z. Q.

    2010-03-01

    With the advantages of less gas consumption, higher carrying rocks ability, lower leakage and higher penetration rate, foam drilling is widely used today in petroleum industry. In the process of foam underbalanced drilling, the mixture of gas, liquid and cuttings flows upwards through the annular, so it is a typical gas-liquid-solid multi-phase flow. In order to protect the reservoir and avoid borehole wall collapsing during foam drilling, it is crucial to ensure that the bottom hole pressure is lower than the formation pressure and higher than the formation collapse pressure, and in the mean time, foam drilling fluid in the whole wellbore should be in the best foam quality stage in order to have sufficient capacity to carry cuttings. In this paper, main relations between bottom hole pressure and gas-liquid injecting rate are analyzed with the underbalanced multiphase flow models. And in order to obtain precise flow pattern and flow pressure, the whole well bore is spatial meshed and iterative method is used. So, a convenient safety window expressed by gas-liquid injecting rate is obtained instead of that by bottom hole pressure. Finally, a foam drilling example from a block in Yemen is presented; the drilling results show that this method is reliable and practical.

  12. Optimized Setup for 2D Convection Experiments in Thin Liquid Films

    CERN Document Server

    Winkler, Michael

    2015-01-01

    We present a novel experimental setup to investigate two-dimensional thermal convection in a freestanding thin liquid film. We develop a setup for the reproducible generation of freestanding thin liquid films. Such films can be produced in a controlled way on the scale of 5 to 1000 nanometers. Our primary goal is to investigate the statistics of reversals in Rayleigh-B\\'enard convection with varying aspect ratio; here numerical works are quite expensive and 3D experiments prohibitively complicated and costly. However, as well questions regarding the physics of liquid films under controlled conditions can be investigated, like surface forces, or stability under varying thermodynamical parameters. The thin liquid film has a well-defined and -chosen chemistry in order to fit our particular requirements, it has a thickness to area ratio of approximately 10^8 and is supported by a frame which is adjustable in height and width to vary the aspect ratio from 0.16 to 10. The top and bottom frame elements can be set to...

  13. Modeling of the flow continuum and optimal design of control-oriented injection systems in liquid composite molding processes

    Science.gov (United States)

    Gokce, Ali

    Several methodologies are presented in this dissertation that aim to ensure successful filling of the mold cavity consistently, during the mold filling stage of Liquid Composite Molding (LCM) processes such as Resin Transfer Molding (RTM), Vacuum Assisted Resin Transfer Molding (VARTM) and Seemann Composites Resin Infusion Molding (SCRIMP). Key parameters that affect the resin flow in the mold cavity can be divided into two main groups as continuum-related parameters and injection-related parameters. Flow continuum, which consists of all the spaces resin can reach in the mold cavity, has two major components: the porous medium, which is made up of the fiber reinforcements, and the flow channels that are introduced into the flow continuum unintentionally and offer an easy flow path to the resin. The properties that characterize the porous medium and the unintentional flow channels are continuum-related parameters. The injection-related parameters include resin injection locations (gates), resin injection conditions and air drainage locations (vents). Modeling the flow continuum is crucial in predicting the resin flow in the mold cavity. In this study, permeability, the key property of the porous medium, is predicted using the Method of Cells, a proven method to predict macroscopic properties of heterogeneous materials. Unintentional flow channels, which are also called racetracking channels, are modeled using a probabilistic approach. Injection-related parameters are the key tools to influence the resin flow in the mold cavity. In this study, Branch and Bound Search is modified for single gate optimization. Due to its pertinence to injection system design, the parameters that govern gate effectiveness in steering the resin advance are studied. A combinatorial search algorithm is proposed for vent optimization. Vent optimization and gate optimization algorithms are integrated for simultaneous gate and vent optimization. Overall, these methodologies reduce the cycle

  14. Monitoring leachables from single-use bioreactor bags for mammalian cell culture by dispersive liquid-liquid microextraction followed by ultra high performance liquid chromatography quadrupole time of flight mass spectrometry.

    Science.gov (United States)

    Dorival-García, N; Bones, J

    2017-08-25

    A method for the identification of leachables in chemically defined media for CHO cell culture using dispersive liquid-liquid microextraction (DLLME) and UHPLC-MS is described. A Box-Behnken design of experiments (DoE) approach was applied to obtain the optimum extraction conditions of the target analytes. Performance of DLLME as extraction technique was studied by comparison of two commercial chemically defined media for CHO cell culture. General extraction conditions for any group of leachables, regardless of their specific chemical functionalities can be applied and similar optimum conditions were obtained with the two media. Extraction efficiency and matrix effects were determined. The method was validated using matrix-matched standard calibration followed by recovery assays with spiked samples. Finally, cell culture media was incubated in 7 single use bioreactors (SUBs) from different vendors and analysed. TBPP was not detected in any of the samples, whereas DtBP and TBPP-ox were found in all samples, with bDtBPP detected in six SUBs. This method can be used for early identification of non-satisfactory SUB films for cultivation of CHO cell lines for biopharmaceutical production. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Optimization ofPleurotus ostreatus liquid medium formula%平菇液体培养基配方研究

    Institute of Scientific and Technical Information of China (English)

    许谦

    2011-01-01

    The influence of corn flour, wheat brain, MgSO4, KH2PO4 on Pleurotus ostreatus mycelium dry weight and extracellular polysaccharide production were studied through orthogonal experiments. The optimal liquid medium formula for Pleurotus ostreatus mycelium was obtained as follows: corn flour 2.5%, wheat brain 2.5%, MgSO4 0.15%, KH2PO4 0.10% and pH value natural. The optimal liquid medium formula for P. Ostreatus exopolysaccharide yield was as follows: corn flour 2.5%, wheat brain 2.5%, MgSO4 0.15%, KH2PO4 0.20% and pH value natural.%通过正交试验研究了平菇液体培养基配方,筛选出适宜平菇菌丝体生长的最佳液体培养基配方为玉米粉2.5%,麸皮2.5%,MgSO40.15%,KH2PO4 0.10%,pH值为自然;适宜平菇胞外多糖产生的最佳液体培养基配方为玉米粉2.5%,麸皮2.5%,MgSO4 0.15%,KH2PO4 0.20%,pH值为自然.

  16. Optimization of culture conditions of Arnica montana L.: effects of mycorrhizal fungi and competing plants.

    Science.gov (United States)

    Jurkiewicz, Anna; Ryszka, Przemyslaw; Anielska, Teresa; Waligórski, Piotr; Białońska, Dobroslawa; Góralska, Katarzyna; Tsimilli-Michael, Merope; Turnau, Katarzyna

    2010-06-01

    Arnica montana is a rare plant that needs special protection because of its intensive harvesting for medicinal purposes. The present work was aimed at finding optimal culture conditions for Arnica plants in order to enable their successful reintroduction into their natural stands. Plants were cultivated under controlled greenhouse conditions on substrata with different nitrogen (N) concentration. As Arnica is always colonized by arbuscular mycorrhizal fungi (AMF) in nature, a fact that has been overlooked in other similar projects, we, here, applied and tested different inocula. We found that they differed in their effectiveness, both in establishing symbiosis, assessed by the colonization parameters, and in improving the performance of Arnica, evaluated by the photosynthetic parameters derived from the fluorescence transients (JIP-test), with the inocula containing G. intraradices or composed of several Glomus strains being the most effective. The comparison was possible only on substrata with medium N, since high N did not permit the formation of mycorrhiza, while at low N, few nonmycorrhizal plants survived until the measurements and mycorrhizal plants, which were well growing, exhibited a high heterogeneity. Analysis of secondary metabolites showed clearly that mycorrhization was associated with increased concentrations of phenolic acids in roots. For some of the inocula used, a tendency for increase of the level of phenolic acids in shoots and of sesquiterpene lactones, both in roots and in shoots, was also observed. We also studied the interactions between A. montana and Dactylis glomerata, known to compete with Arnica under field conditions. When specimens from both species were cultured together, there was no effect on D. glomerata, but Arnica could retain a photosynthetic performance that permitted survivability only in the presence of AMF; without AMF, the photosynthetic performance was lower, and the plants were eventually totally outcompeted.

  17. Screening and characterization of Isochrysis strains and optimization of culture conditions for docosahexaenoic acid production.

    Science.gov (United States)

    Liu, Jin; Sommerfeld, Milton; Hu, Qiang

    2013-06-01

    Isochrysis is a genus of marine unicellular microalgae that produces docosahexaenoic acid (DHA, C22:6), a very long chain polyunsaturated fatty acid (PUFA) of significant health and nutritional value. Mass cultivation of Isochrysis for DHA production for human consumption has not been established due to disappointing low DHA productivity obtained from commonly used Isochrysis strains. In this study, 19 natural Isochrysis strains were screened for DHA yields and the results showed that the cellular DHA content ranged from 6.8 to 17.0 % of total fatty acids with the highest DHA content occurring in the exponential growth phase. Isochrysis galbana #153180 exhibited the greatest DHA production potential and was selected for further investigation. The effects of different light intensities, forms, and concentrations of nitrogen, phosphorus, and salinity on growth and DHA production of I. galbana #153180 were studied in a bubble column photobioreactor (PBR). Under favorable culture conditions, I. galbana #153180 contained DHA up to 17.5 % of total fatty acids or 1.7 % of cell dry weight. I. galbana #153180 was further tested in outdoor flat-plate PBRs varying in light path length, starting cell density (SCD), and culture mode (batch versus semicontinuous). When optimized, record high biomass and DHA productivity of I. galbana #153180 of 0.72 g L(-1) day(-1) and 13.6 mg L(-1) day(-1), or 26.4 g m(-2) day(-1) and 547.7 mg m(-2) day(-1), respectively, were obtained, suggesting that I. galbana #153180 may be a desirable strain for commercial production of DHA.

  18. Optimization of lignin production from empty fruit bunch via liquefaction with ionic liquid.

    Science.gov (United States)

    Sidik, Dilaeleyana Abu Bakar; Ngadi, Norzita; Amin, Nor Aishah Saidina

    2013-05-01

    The production of lignin from empty fruit bunch (EFB) has been carried out using liquefaction method with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid (IL), in presence of sulfuric acid (H2SO4) as a catalyst. Response surface methodology (RSM) based on a factorial Central Composite Design (CCD) was employed to identify the optimum condition for lignin yield. The result indicated that the second order model was adequate for all the independent variables on the response with R(2)=0.8609. The optimum temperature, time, ionic liquid to EFB ratio, and catalyst concentration were 150.5 °C, 151 min, 3:1 wt/wt and 4.73 wt%, respectively for lignin yield=26.6%. The presence of lignin liquefied product was confirmed by UV-Vis and FTIR analysis. It was also demonstrated lignin extraction from lignocellulosic using recycled IL gave sufficient performance.

  19. Optimal methods for identifying the pollution level of liquid mediums. Opticheskiye metody opredeleniya zagryaznennosti zhidkikh sred

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, G.F.; Novichkov, M.N.; Timofeyev, V.F.

    1984-01-01

    The results are cited of experimental studies performed between 1964 and 1982, the nature and dispersion composition of pollutants are examined and the contemporary specifications on the purity and methods for testing fuel are presented. Practical recommendations are given for developing new high speed methods for evaluating the contamination of fuels and oils. These data are important for studies of the processes of transformation of homogeneous liquid mediums into heterogeneous ones.

  20. Optimization of primary culture condition for mesenchymal stem cells derived from umbilical cord blood with factorial design.

    Science.gov (United States)

    Fan, Xiubo; Liu, Tianqing; Liu, Yang; Ma, Xuehu; Cui, Zhanfeng

    2009-01-01

    Mesenchymal stem cells (MSCs) can not only support the expansion of hematopoietic stem cells in vitro, but also alleviate complications and accelerate recovery of hematopoiesis during hematopoietic stem cell transplantation. However, it proved challenging to culture MSCs from umbilical cord blood (UCB) with a success rate of 20-30%. Many cell culture parameters contribute to this outcome and hence optimization of culture conditions is critical to increase the probability of success. In this work, fractional factorial design was applied to study the effect of cell inoculated density, combination and dose of cytokines, and presence of serum and stromal cells. The cultured UCB-MSC-like cells were characterized by flow cytometry and their multilineage differentiation potentials were tested. The optimal protocol was identified achieving above 90% successful outcome: 2 x 10(6) cells/mL mononuclear cells inoculated in Iscove's modified Dulbecco's medium supplied with 10% FBS, 15 ng/mL IL-3, and 5 ng/mL Granulocyte-macrophage colony-stimulating factor (GM-CSF). Moreover, the UCB-MSC-like cells expressed MSC surface markers of CD13, CD29, CD105, CD166, and CD44 positively, and CD34, CD45, and human leukocyte antigens-DR (HLA-DR) negatively. Meanwhile, these cells could differentiate into osteoblasts, chondrocytes, and adipocytes similarly to MSCs derived from bone marrow. In conclusion, we have developed an efficient protocol for the primary culture of UCB-MSCs by adding suitable cytokines into the culture system.

  1. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results.

    Science.gov (United States)

    Bordag, Natalie; Janakiraman, Vijay; Nachtigall, Jonny; González Maldonado, Sandra; Bethan, Bianca; Laine, Jean-Philippe; Fux, Elie

    2016-01-01

    The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench) followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli) as well as mammalian cells chinese hamster ovary (CHO) and mouse myeloma cells (NS0).The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data.

  2. Production of microsclerotia by brazilian strains of metarhizium spp. using submerged liquid culture fermentation

    Science.gov (United States)

    We investigated the potential production and desiccation tolerance of microsclerotia (MS) by Brazilian strains of Metarhizium. anisopliae [Ma], M. acridum [Mc] and M. robertsii [Mr]. These fungi were grown in a liquid medium containing 16 g carbon l-1 with a carbon:nitrogen ratio of 50:1. One hundre...

  3. Optimization of the enterprise’s innovative culture level from the standpoint of ensuring its economic security

    Directory of Open Access Journals (Sweden)

    Yu.S. Shypulina

    2015-06-01

    Full Text Available The aim of the article. The article is to determine the role of enterprise’s innovative culture to ensure its economic security and develop the methodical approach to the optimization of the enterprise’s innovative culture level from the standpoint of ensuring its economic security. The results of the analysis. It is shown that innovations and innovative activity are natural means to adapt to changes in macro- and microenvironment of the enterprise in permanently changing modern economy. Innovations and innovative activity are the backgrounds of economic security. One of the main factors of the formation of the environment conducive to innovation at the enterprise is its innovative culture, viewed as a mechanism for regulation of social and cultural innovation behavior of its staff. Accordingly, the innovative culture is also an important component of a mechanism ensuring economic security. It should be considered as a condition of effective use of enterprise’s resources and market opportunities, what prevents internal and external threats and ensures enterprise’s survival and sustainable development at the market in accordance with the selected mission and motivation activity. The results of the research confirm that economic security is a function of its innovative culture. The level of innovation culture depends on the expenses for its development. The author developed a methodical approach to determine the optimal level of enterprise’s innovative culture according to the «economic security/expenses» criterion under the given constraints: the financial costs and risk. A mathematical model realizing this methodical approach was also elaborated. Testing of the developed econometric model confirmed its adequacy and proved the feasibility of its implementation for optimization of enterprise’s innovative culture level from the standpoint of ensuring its economic security. Conclusions and directions of further researches. The results

  4. Efficient generation of multipotent mesenchymal stem cells from umbilical cord blood in stroma-free liquid culture.

    Directory of Open Access Journals (Sweden)

    Rowayda Peters

    Full Text Available BACKGROUND: Haematopoiesis is sustained by haematopoietic (HSC and mesenchymal stem cells (MSC. HSC are the precursors for blood cells, whereas marrow, stroma, bone, cartilage, muscle and connective tissues derive from MSC. The generation of MSC from umbilical cord blood (UCB is possible, but with low and unpredictable success. Here we describe a novel, robust stroma-free dual cell culture system for long-term expansion of primitive UCB-derived MSC. METHODS AND FINDINGS: UCB-derived mononuclear cells (MNC or selected CD34(+ cells were grown in liquid culture in the presence of serum and cytokines. Out of 32 different culture conditions that have been tested for the efficient expansion of HSC, we identified one condition (DMEM, pooled human AB serum, Flt-3 ligand, SCF, MGDF and IL-6; further denoted as D7 which, besides supporting HSC expansion, successfully enabled long-term expansion of stromal/MSC from 8 out of 8 UCB units (5 MNC-derived and 3 CD34(+ selected cells. Expanded MSC displayed a fibroblast-like morphology, expressed several stromal/MSC-related antigens (CD105, CD73, CD29, CD44, CD133 and Nestin but were negative for haematopoietic cell markers (CD45, CD34 and CD14. MSC stemness phenotype and their differentiation capacity in vitro before and after high dilution were preserved throughout long-term culture. Even at passage 24 cells remained Nestin(+, CD133(+ and >95% were positive for CD105, CD73, CD29 and CD44 with the capacity to differentiate into mesodermal lineages. Similarly we show that UCB derived MSC express pluripotency stem cell markers despite differences in cell confluency and culture passages. Further, we generated MSC from peripheral blood (PB MNC of 8 healthy volunteers. In all cases, the resulting MSC expressed MSC-related antigens and showed the capacity to form CFU-F colonies. CONCLUSIONS: This novel stroma-free liquid culture overcomes the existing limitation in obtaining MSC from UCB and PB enabling so far unmet

  5. Optimized high performance liquid chromatography-ultraviolet detection method using core-shell particles for the therapeutic monitoring of methotrexate$

    Institute of Scientific and Technical Information of China (English)

    Milagros Montemurro; María M. De Zan n; Juan C. Robles

    2016-01-01

    Methotrexate (MTX) is an antineoplastic drug, and due to its high toxicity, the therapeutic drug mon-itoring is strictly conducted in the clinical practice. The chemometric optimization and validation of a high performance liquid chromatography (HPLC) method using core–shell particles is presented for the determination of MTX in plasma during therapeutic monitoring. Experimental design and response surface methodology (RSM) were applied for the optimization of the chromatographic system and the analyte extraction step. A Poroshell 120 EC-C18 (3.0 mm ? 75 mm, 2.7μm) column was used to obtain a fast and efficient separation in a complete run time of 4 min. The optimum conditions for the chroma-tographic system resulted in a mobile phase consisting of acetic acid/sodium acetate buffer solution (85.0 mM, pH¼4.00) and 11.2%of acetonitrile at a flow rate of 0.4 mL/min. Selectivity, linearity, accuracy and precision were demonstrated in a range of 0.10–6.0 mM of MTX. The application of the optimized method required only 150 mL of patient plasma and a low consumption of solvent to provide rapid re-sults.

  6. Shape optimization of a sheet swimming over a thin liquid layer

    Energy Technology Data Exchange (ETDEWEB)

    Wilkening, J.; Hosoi, A.E.

    2008-12-10

    Motivated by the propulsion mechanisms adopted by gastropods, annelids and other invertebrates, we consider shape optimization of a flexible sheet that moves by propagating deformation waves along its body. The self-propelled sheet is separated from a rigid substrate by a thin layer of viscous Newtonian fluid. We use a lubrication approximation to model the dynamics and derive the relevant Euler-Lagrange equations to simultaneously optimize swimming speed, efficiency and fluid loss. We find that as the parameters controlling these quantities approach critical values, the optimal solutions become singular in a self-similar fashion and sometimes leave the realm of validity of the lubrication model. We explore these singular limits by computing higher order corrections to the zeroth order theory and find that wave profiles that develop cusp-like singularities are appropriately penalized, yielding non-singular optimal solutions. These corrections are themselves validated by comparison with finite element solutions of the full Stokes equations, and, to the extent possible, using recent rigorous a-priori error bounds.

  7. Mating and Optimization Parameters for High-Temperature Liquid Metal Wetting on Solid Substrates

    Science.gov (United States)

    2014-04-01

    wicking thermal transport systems operating in a high temperature environment. Success in accomplishing the program objective would contribute to...enhancing the extreme cooling of shock wave heat from in-flight conditions experienced by supersonic/ hypersonic vehicles. The mating and optimization

  8. Optimization of a Culture Medium Using the Taguchi Approach for the Production of Microorganisms Active in Odorous Compound Removal

    Directory of Open Access Journals (Sweden)

    Krzysztof Makowski

    2017-07-01

    Full Text Available The aim of this work was to develop the composition of a medium for the cultivation of six microbial strains forming a deodorizing consortium: Pseudomonas fluorescens, Enterococcus faecium, Bacillus subtilis, Bacillus megaterium, Leuconostoc mesenteroides and Lactobacillus plantarum. The study focused on the optimization of a highly efficient culture medium composed of readily available components of plant origin to maximize microbial biomass yields, and to create a less expensive alternative to the commercial Tryptic Soy Broth medium (TSB. After preliminary efficiency screening of all tested media components, we selected four substrates for further optimization—soy protein concentrate (SPC, glucose or sucrose, and phosphate salts. The final concentrations of all components were fine-tuned using the Taguchi design for experiments according to an L9 array. Taguchi optimization led to formulation of a culture medium, which was approximately 5 times cheaper than TSB (depending on the components used. Consequently, microbial biomass yields were improved by up to 15-fold (1564%, depending on the strain. The results obtained in the laboratory experiments were then confirmed in pilot- (42 L and industrial- (300 L scale fermentation. Our results show that this method of using a parallel culture microbioreactor with the Taguchi approach can be recommended for optimization of culture media based on substrates of plant origin.

  9. Macro-circuit simulation and optimal design for ferroelectric liquid crystal based on dielectric properties

    Institute of Scientific and Technical Information of China (English)

    Wang Mengyao; Pan Wei; Luo Bin; Zhang Weili; Zou Xihua; Xiong Yue

    2007-01-01

    A macro-circuit equivalent model for ferroelectric liquid crystal(FLC)is proposed.The model includes both effects of ferroelectric torque and dielectric torque and is utilized to simulate the switching response and memory behavior of a single FLC cell.Simulation results show that the delay time has a minimum while increasing the amplitude of drive voltage and the amplitude of bipolar pulses should be controlled within a certain range to realize the memory behavior.Also the switching angle is successfully enhanced to the reference value of 22.5°by adopting"AC stabilization"addressing method.

  10. Central bank balance sheet concerns and credible optimal escape from the Liquidity trap

    OpenAIRE

    Mendes, Arthur Galego

    2001-01-01

    I show that when a central bank is financially independent from the treasury and has balance sheet concerns, an increase in the size or a change in the composition of the central bank's balance sheet (quantitative easing) can serve as a commitment device in a liquidity trap scenario. In particular, when the short-term interest rate is up against the zero lower bound, an open market operation by the central bank that involves purchases of long-term bonds can help mitigate the ...

  11. Central bank balance sheet concerns and credible optimal escape from the Liquidity trap

    OpenAIRE

    Mendes, Arthur Galego

    2001-01-01

    I show that when a central bank is financially independent from the treasury and has balance sheet concerns, an increase in the size or a change in the composition of the central bank's balance sheet (quantitative easing) can serve as a commitment device in a liquidity trap scenario. In particular, when the short-term interest rate is up against the zero lower bound, an open market operation by the central bank that involves purchases of long-term bonds can help mitigate the ...

  12. Optimization of culture medium for lactosucrose ( G-beta-D-galactosylsucrose) Production by Sterigmatomyces elviae mutant using statistical analysis.

    Science.gov (United States)

    Lee, Jong Ho; Lim, Jung Soo; Song, Yoon Seok; Kang, Seong Woo; Park, Chulhwan; Kim, Seung Wook

    2007-12-01

    In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose ((4)G-beta-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.

  13. Tracheobronchial air-liquid interface cell culture: a model for innate mucosal defense of the upper airways?

    Science.gov (United States)

    Kesimer, Mehmet; Kirkham, Sara; Pickles, Raymond J.; Henderson, Ashley G.; Alexis, Neil E.; DeMaria, Genevieve; Knight, David; Thornton, David J.; Sheehan, John K.

    2009-01-01

    Human tracheobronchial epithelial cells grown in air-liquid interface culture have emerged as a powerful tool for the study of airway biology. In this study, we have investigated whether this culture system produces “mucus” with a protein composition similar to that of in vivo, induced airway secretions. Previous compositional studies of mucous secretions have greatly underrepresented the contribution of mucins, which are major structural components of normal mucus. To overcome this limitation, we have used a mass spectrometry-based approach centered on prior separation of the mucins from the majority of the other proteins. Using this approach, we have compared the protein composition of apical secretions (AS) from well-differentiated primary human tracheobronchial cells grown at air-liquid interface and human tracheobronchial normal induced sputum (IS). A total of 186 proteins were identified, 134 from AS and 136 from IS; 84 proteins were common to both secretions, with host defense proteins being predominant. The epithelial mucins MUC1, MUC4, and MUC16 and the gel-forming mucins MUC5B and MUC5AC were identified in both secretions. Refractometry showed that the gel-forming mucins were the major contributors by mass to both secretions. When the composition of the IS was corrected for proteins that were most likely derived from saliva, serum, and migratory cells, there was considerable similarity between the two secretions, in particular, in the category of host defense proteins, which includes the mucins. This shows that the primary cell culture system is an important model for study of aspects of innate defense of the upper airways related specifically to mucus consisting solely of airway cell products. PMID:18931053

  14. Optimally accepted salt reduction across cultures. Naturally brewed soy sauce used in three countries with different food cultures

    NARCIS (Netherlands)

    Shimojo, R.; Sato, T.; Imamura, M.; Leong, L.P.; Itohiya, Y.; Kremer, S.; Mojet, J.

    2014-01-01

    To explore the influence of food-culture on partial replacement of salt by naturally brewed soy sauce, the results of a procedure, based on equivalence of overall taste intensity and pleasantness, were compared in three countries. Per country, untrained consumers assessed pleasantness and some senso

  15. Optimization of pressurized liquid extraction of inositols from pine nuts (Pinus pinea L.).

    Science.gov (United States)

    Ruiz-Aceituno, L; Rodríguez-Sánchez, S; Sanz, J; Sanz, M L; Ramos, L

    2014-06-15

    Pressurized liquid extraction (PLE) has been used for the first time to extract bioactive inositols from pine nuts. The influence of extraction time, temperature and cycles of extraction in the yield and composition of the extract was studied. A quadratic lineal model using multiple linear regression in the stepwise mode was used to evaluate possible trends in the process. Under optimised PLE conditions (50°C, 18 min, 3 cycles of 1.5 mL water each one) at 10 MPa, a noticeable reduction in extraction time and solvent volume, compared with solid-liquid extraction (SLE; room temperature, 2h, 2 cycles of 5 mL water each one) was achieved; 5.7 mg/g inositols were extracted by PLE, whereas yields of only 3.7 mg/g were obtained by SLE. Subsequent incubation of PLE extracts with Saccharomyces cerevisiae (37°C, 5h) allowed the removal of other co-extracted low molecular weight carbohydrates which may interfere in the bioactivity of inositols.

  16. Improved detection of multiple environmental antibiotics through an optimized sample extraction strategy in liquid chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Yi, Xinzhu; Bayen, Stéphane; Kelly, Barry C; Li, Xu; Zhou, Zhi

    2015-12-01

    A solid-phase extraction/liquid chromatography/electrospray ionization/multi-stage mass spectrometry (SPE-LC-ESI-MS/MS) method was optimized in this study for sensitive and simultaneous detection of multiple antibiotics in urban surface waters and soils. Among the seven classes of tested antibiotics, extraction efficiencies of macrolides, lincosamide, chloramphenicol, and polyether antibiotics were significantly improved under optimized sample extraction pH. Instead of only using acidic extraction in many existing studies, the results indicated that antibiotics with low pK a values (antibiotics with high pK a values (>7) were extracted more efficiently under neutral conditions. The effects of pH were more obvious on polar compounds than those on non-polar compounds. Optimization of extraction pH resulted in significantly improved sample recovery and better detection limits. Compared with reported values in the literature, the average reduction of minimal detection limits obtained in this study was 87.6% in surface waters (0.06-2.28 ng/L) and 67.1% in soils (0.01-18.16 ng/g dry wt). This method was subsequently applied to detect antibiotics in environmental samples in a heavily populated urban city, and macrolides, sulfonamides, and lincomycin were frequently detected. Antibiotics with highest detected concentrations were sulfamethazine (82.5 ng/L) in surface waters and erythromycin (6.6 ng/g dry wt) in soils. The optimized sample extraction strategy can be used to improve the detection of a variety of antibiotics in environmental surface waters and soils.

  17. Optimization of methane conversion to liquid fuels over W-Cu/ZSM-5 catalysts by response surface methodology

    Institute of Scientific and Technical Information of China (English)

    Didi Dwi Anggoro; Istadi

    2008-01-01

    The conversion of methane to liquid fuels is still in the development process. The modified HZSM-5 by loading with Tungsten (W) enhanced its heat resistant performance, and the high reaction temperature (800 ℃) did not lead to the loss of W component by sublimation. The loading of ZSM-5 with Tungsten and Copper (Cu) resulted in an increment in the methane conversion, CO2, and C5+ selectivities. The high methane conversion and C5+ selectivity, and low H2O selectivity are obtained by using W/3.OCu/ZSM-5. The optimization of methane conversion over 3.0 W/3.0Cu/ZSM-5 under different temperature and oxygen concentration using response surface methodology (RSM) are studied. The optimum point for methane conversion is 19% when temperature is 753 ℃, and oxygen concentration is 12%. The highest C5+ selectivity is 27% when temperature is 751 ℃, and oxygen concentration is 11%.

  18. Densification and volumetric change during supersolidus liquid phase sintering of prealloyed brass Cu28Zn powder: Modeling and optimization

    Directory of Open Access Journals (Sweden)

    Mohammadzadeh A.

    2014-01-01

    Full Text Available An investigation has been made to use response surface methodology and central composite rotatable design for modeling and optimizing the effect of sintering variables on densification of prealloyed Cu28Zn brass powder during supersolidus liquid phase sintering. The mathematical equations were derived to predict sintered density, densification parameter, porosity percentage and volumetric change of samples using second order regression analysis. As well as the adequacy of models was evaluated by analysis of variance technique at 95% confidence level. Finally, the influence and interaction of sintering variables, on achieving any desired properties was demonstrated graphically in contour and three dimensional plots. In order to better analyze the samples, microstructure evaluation was carried out. It was concluded that response surface methodology based on central composite rotatable design, is an economical way to obtain arbitrary information with performing the fewest number of experiments in a short period of time.

  19. An optimized gossypol high-performance liquid chromatography assay and its application in evaluation of different gland genotypes of cotton

    Indian Academy of Sciences (India)

    Yingfan Cai; Hong Zhang; Yu Zeng; Jianchuan Mo; Jinku Bao; Chen Miao; Jie Bai; Fang Yan; Fang Chen

    2004-03-01

    A comparative study on gossypol content of various genetic types of pigment glands of cotton varieties was conducted through an optimized high-performance liquid chromatography (HPLC) on a C18 column (4.6 mm × 250 mm, 5 m particle) with methanol–0.5% acetic acid aqueous solution, 90 : 10 (v/v), as mobile phase, at a flow rate of 0.8 ml/min and UV detection at 254 nm. The method was shown to be highly reproducible, with precision [as relative standard deviation (RSD)] and accuracy [as relative mean error (RME)] < 10%, both intra-day and inter-day. Absolute recoveries were > 94%. The results revealed major differences among the different gland varieties or species of cotton, including the special and ordinary glandless and glanded Gossypium hirsutum, G. barbadense, and displayed the precious resources of different glands of extraordinary cotton.

  20. Optimization of a single-phase liquid xenon Compton camera for 3γ medical imaging

    OpenAIRE

    Gallego Manzano, Lucia

    2016-01-01

    The work described in this thesis is focused on the characterization and optimization of a single-phaseliquid xenon Compton camera for medical imaging applications. The detector has been conceived to exploit the advantages of an innovative medical imaging technique called 3γ imaging, which aims to obtain aprecise 3D location of a radioactive source with high sensitivity and an important reduction of the dose administered to the patient. The 3γ imaging technique is based on the detection in co...

  1. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results.

    Directory of Open Access Journals (Sweden)

    Natalie Bordag

    Full Text Available The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli as well as mammalian cells chinese hamster ovary (CHO and mouse myeloma cells (NS0.The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data.

  2. Optimizing immobilized enzyme performance in cell-free environments to produce liquid fuels.

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanat

    2015-02-05

    The overall goal of this project was to optimize enzyme performance for the production of bio-diesel fuel. Enzyme immobilization has attracted much attention as a means to increase productivity. Mesorporous silica materials have been known to be best suited for immobilizing enzymes. A major challenge is to ensure that the enzymatic activity is retained after immobilization. Two major factors which drive enzymatic deactivation are protein-surface and inter-protein interactions. Previously, we studied protein stability inside pores and how to optimize protein-surface interactions to minimize protein denaturation. In this work we studied eh effect of surface curvature and chemistry on inter-protein interactions. Our goal was to find suitable immobilization supports which minimize these inter-protein interactions. Our studies carried out in the frame work of Hydrophobic-Polar (HP) model showed that enzymes immobilized inside hydrophobic pores of optimal sizes are best suited to minimize these inter-protein interactions. Besides, this study is also of biological importance to understand the role of chaperonins in protein disaggregation. Both of these aspects profited immensely with collaborations with our experimental colleague, Prof. Georges Belfort (RPI), who performed the experimental analog of our theoretical works.

  3. Retention prediction and separation optimization under multilinear gradient elution in liquid chromatography with Microsoft Excel macros.

    Science.gov (United States)

    Fasoula, S; Zisi, Ch; Gika, H; Pappa-Louisi, A; Nikitas, P

    2015-05-22

    A package of Excel VBA macros have been developed for modeling multilinear gradient retention data obtained in single or double gradient elution mode by changing organic modifier(s) content and/or eluent pH. For this purpose, ten chromatographic models were used and four methods were adopted for their application. The methods were based on (a) the analytical expression of the retention time, provided that this expression is available, (b) the retention times estimated using the Nikitas-Pappa approach, (c) the stepwise approximation, and (d) a simple numerical approximation involving the trapezoid rule for integration of the fundamental equation for gradient elution. For all these methods, Excel VBA macros have been written and implemented using two different platforms; the fitting and the optimization platform. The fitting platform calculates not only the adjustable parameters of the chromatographic models, but also the significance of these parameters and furthermore predicts the analyte elution times. The optimization platform determines the gradient conditions that lead to the optimum separation of a mixture of analytes by using the Solver evolutionary mode, provided that proper constraints are set in order to obtain the optimum gradient profile in the minimum gradient time. The performance of the two platforms was tested using experimental and artificial data. It was found that using the proposed spreadsheets, fitting, prediction, and optimization can be performed easily and effectively under all conditions. Overall, the best performance is exhibited by the analytical and Nikitas-Pappa's methods, although the former cannot be used under all circumstances.

  4. Impedance magnitude optimization of the regenerator in Stirling pulse tube cryocoolers working at liquid-helium temperatures

    Science.gov (United States)

    Cao, Q.; Qiu, L. M.; Zhi, X. Q.; Han, L.; Gan, Z. H.; Zhang, X. B.; Zhang, X. J.; Sun, D. M.

    2013-12-01

    The impedance magnitude is important for the design and operation of a Stirling pulse tube cryocooler (SPTC). However, the influence of the impedance magnitude on the SPTC working at liquid-helium temperatures is still not clear due to the complexity of refrigeration mechanism at this temperature range. In this study, the influence of the impedance magnitude on the viscous and thermal losses has been investigated, which contributes to the overall refrigeration efficiency. Different from the previous study at liquid nitrogen temperatures, it has been found and verified experimentally that a higher impedance magnitude may result in a larger mass flow rate accompanied with larger losses in the warmer region, hence the refrigeration efficiency is lowered. Numerical simulation is carried out in SPTCs of different geometry dimensions and working parameters, and the experimental study is carried out in a three-stage SPTC. A minimum no-load refrigeration temperature is achieved with an appropriate impedance magnitude that is determined by the combination of frequency and precooling temperature. A lowest temperature of 4.76 K is achieved at 28 Hz and a precooling temperature of 22.6 K, which is the lowest temperature ever achieved with He-4 for SPTCs. Impedance magnitude optimization is clearly an important consideration for the design of a 4 K SPTC.

  5. An impedance-measurement setup optimized for measuring relaxations of glass-forming liquids.

    Science.gov (United States)

    Igarashi, Brian; Christensen, Tage; Larsen, Ebbe H; Olsen, Niels Boye; Pedersen, Ib H; Rasmussen, Torben; Dyre, Jeppe C

    2008-04-01

    An electronics system has been assembled to measure frequency-dependent response functions of glass-forming liquids in the extremely viscous state approaching the glass transition. We determine response functions such as dielectric permittivity and shear and bulk moduli by measuring electrical impedances of liquid-filled transducers, and this technique requires frequency generators capable of producing signals that are reproducible over the span of several days or even several weeks. To this end, we have constructed a frequency generator that produces low-frequency (1 mHz-100 Hz) sinusoidal signals with voltages that are reproducible within 10 ppm. Two factors that partly account for this precision are that signals originate from voltages stored in a look-up table and that only coil-less filters are used in this unit, which significantly reduces fluctuations of output caused by changes of temperatures of circuits. This generator also includes a special triggering facility that makes it possible to measure up to 512 voltages per cycle that are spaced apart at uniform phase intervals. Fourier transformations of such data yield precise determinations of complex amplitudes of voltages and currents applied to a transducer, which ultimately allows us to determine electrical impedances of transducers with a reproducibility error that is only a few parts per hundred thousand. This equipment is used in tandem with a commercial LCR meter and/or impedance analyzer that give(s) impedance measurements at higher frequencies, up to 1 MHz. The experimental setup allows measurements of the transducer impedance over nine decades of frequency within a single run.

  6. Increasing efficiency of human mesenchymal stromal cell culture by optimization of microcarrier concentration and design of medium feed.

    Science.gov (United States)

    Chen, Allen Kuan-Liang; Chew, Yi Kong; Tan, Hong Yu; Reuveny, Shaul; Weng Oh, Steve Kah

    2015-02-01

    Large amounts of human mesenchymal stromal cells (MSCs) are needed for clinical cellular therapy. In a previous publication, we described a microcarrier-based process for expansion of MSCs. The present study optimized this process by selecting suitable basal media, microcarrier concentration and feeding regime to achieve higher cell yields and more efficient medium utilization. MSCs were expanded in stirred cultures on Cytodex 3 microcarriers with media containing 10% fetal bovine serum. Process optimization was carried out in spinner flasks. A 2-L bioreactor with an automated feeding system was used to validate the optimized parameters explored in spinner flask cultures. Minimum essential medium-α-based medium supported faster MSC growth on microcarriers than did Dulbecco's modified Eagle's medium (doubling time, 31.6 ± 1.4 vs 42 ± 1.7 h) and shortened the process time. At microcarrier concentration of 8 mg/mL, a high cell concentration of 1.08 × 10(6) cells/mL with confluent cell concentration of 4.7 × 10(4)cells/cm(2) was achieved. Instead of 50% medium exchange every 2 days, we have designed a full medium feed that is based on glucose consumption rate. The optimal medium feed that consisted of 1.5 g/L glucose supported MSC growth to full confluency while achieving the low medium usage efficiency of 3.29 mL/10(6)cells. Finally, a controlled bioreactor with the optimized parameters achieved maximal confluent cell concentration with 16-fold expansion and a further improved medium usage efficiency of 1.68 mL/10(6)cells. We have optimized the microcarrier-based platform for expansion of MSCs that generated high cell yields in a more efficient and cost-effective manner. This study highlighted the critical parameters in the optimization of MSC production process. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  7. Optimization of Solid-Liquid Extraction of Antioxidants from Black Mulberry Leaves by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Zoran Zeković

    2012-01-01

    Full Text Available The extraction of active components from natural sources depends on different factors. The knowledge of the effects of different extraction parameters is useful for the optimization of the process, as well for the ability to predict the extraction yield. The aim of this study is to examine the influence of solvent concentration (ethanol/water 40–80 %, by volume, temperature (40–80 °C and solvent/raw material ratio (10–30 mL/g on the extraction yield of phenolic compounds, flavonoids and antioxidant activity from black mulberry (Morus nigra L. leaves. Experimental values of total phenolic content were in the range from 18.6 to 48.7 mg of chlorogenic acid equivalents per g of dried leaves and total flavonoids in the range from 6.0 to 21.4 mg of rutin eqivalents per g of dried leaves. Antioxidant activity expressed as the inhibition concentration at 50 % (IC50 value was in the range from 0.019 to 0.078 mg of mulberry extract per mL. Response surface methodology (RSM was used to determine the optimum extraction conditions and to investigate the effect of different variables on the observed properties of mulberry leaf extracts. The results show a good fit to the proposed model (R˄2>0.90. The optimal conditions for obtaining the highest extraction yield of phenolics and flavonoids were within the experimental range. The experimental values agreed with those predicted, thus indicating suitability of the used model and the success of RSM in optimizing the investigated extraction conditions.

  8. Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth

    Science.gov (United States)

    da Silva, Cíntia Reis; Silva, Marilia Lordelo Cardoso; Kamida, Helio Mitoshi; Goes-Neto, Aristoteles; Koblitz, Maria Gabriela Bello

    2014-01-01

    Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment. PMID:25473487

  9. Optimization of Chlorella vulgaris and bioflocculant-producing bacteria co-culture: enhancing microalgae harvesting and lipid content.

    Science.gov (United States)

    Wang, Y; Yang, Y; Ma, F; Xuan, L; Xu, Y; Huo, H; Zhou, D; Dong, S

    2015-05-01

    Microalgae are a sustainable bioresource, and the biofuel they produce is widely considered to be an alternative to limited natural fuel resources. However, microalgae harvesting is a bottleneck in the development of technology. Axenic Chlorella vulgaris microalgae exhibit poor harvesting, as expressed by a flocculation efficiency of 0·2%. This work optimized the co-culture conditions of C. vulgaris and bioflocculant-producing bacteria in synthetic wastewater using response surface methodology (RSM), thus aiming to enhance C. vulgaris harvesting and lipid content. Three significant process variables- inoculation ratio of bacteria and microalgae, initial glucose concentration, and co-culture time- were proposed in the RSM model. F-values (3·98/8·46) and R(2) values (0·7817/0·8711) both indicated a reasonable prediction by the RSM model. The results showed that C. vulgaris harvesting efficiency reached 45·0-50·0%, and the lipid content was over 21·0% when co-cultured with bioflocculant-producing bacteria under the optimized culture conditions of inoculation ratio of bacteria and microalgae of 0·20-0·25, initial glucose concentration of microalgae harvesting and cost-effective microalgal bioproducts, and confirmed the promising prospect of introducing bioflocculant-producing bacteria into microalgae bioenergy production. This work optimized the co-culture conditions of microalgae (C. vulgaris) and bioflocculant-producing bacteria (F2, Rhizobium radiobacter) in synthetic wastewater using response surface methodology, aiming to enhance C. vulgaris harvesting and lipid produced content. Bioflocculant-producing microbes are environmentally friendly functional materials. They avoid the negative effects of traditional chemical flocculants. This work provided new insights into microalgae harvesting and cost-effective production of microalgal bioproducts, and confirmed the promising prospect of introducing bioflocculant-producing bacteria into microalgae

  10. Trade-off between learning and exploitation: the Pareto-optimal versus evolutionarily stable learning schedule in cumulative cultural evolution.

    Science.gov (United States)

    Wakano, Joe Yuichiro; Miura, Chiaki

    2014-02-01

    Inheritance of culture is achieved by social learning and improvement is achieved by individual learning. To realize cumulative cultural evolution, social and individual learning should be performed in this order in one's life. However, it is not clear whether such a learning schedule can evolve by the maximization of individual fitness. Here we study optimal allocation of lifetime to learning and exploitation in a two-stage life history model under a constant environment. We show that the learning schedule by which high cultural level is achieved through cumulative cultural evolution is unlikely to evolve as a result of the maximization of individual fitness, if there exists a trade-off between the time spent in learning and the time spent in exploiting the knowledge that has been learned in earlier stages of one's life. Collapse of a fully developed culture is predicted by a game-theoretical analysis where individuals behave selfishly, e.g., less learning and more exploiting. The present study suggests that such factors as group selection, the ability of learning-while-working ("on the job training"), or environmental fluctuation might be important in the realization of rapid and cumulative cultural evolution that is observed in humans.

  11. Combined column-mobile phase mixture statistical design optimization of high-performance liquid chromatographic analysis of multicomponent systems.

    Science.gov (United States)

    Breitkreitz, Márcia C; Jardim, Isabel C S F; Bruns, Roy E

    2009-02-27

    A statistical approach for the simultaneous optimization of the mobile and stationary phases used in reversed-phase liquid chromatography is presented. Mixture designs using aqueous mixtures of acetonitrile (ACN), methanol (MeOH) and tetrahydrofuran (THF) organic modifiers were performed simultaneously with column type optimization, according to a split-plot design, to achieve the best separation of compounds in two sample sets: one containing 10 neutral compounds with similar retention factors and another containing 11 pesticides. Combined models were obtained by multiplying a linear model for column type, C8 or C18, by quadratic or special cubic mixture models. Instead of using an objective response function, combined models were built for elementary chromatographic criteria (retention factors, resolution and relative retention) of each solute or pair of solutes and, after their validation, the global separation was accomplished by means of Derringer's desirability functions. For neutral compounds a 37:12:8:43 (v/v/v/v) percentage mixture of ACN:MeOH:THF:H2O with the C18 column and for pesticides a 15:15:70 (v/v/v) ACN:THF:H2O mixture with the C8 column provide excellent resolution of all peaks.

  12. Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  13. Artificial neural network-based model for the prediction of optimal growth and culture conditions for maximum biomass accumulation in multiple shoot cultures of Centella asiatica.

    Science.gov (United States)

    Prasad, Archana; Prakash, Om; Mehrotra, Shakti; Khan, Feroz; Mathur, Ajay Kumar; Mathur, Archana

    2017-01-01

    An artificial neural network (ANN)-based modelling approach is used to determine the synergistic effect of five major components of growth medium (Mg, Cu, Zn, nitrate and sucrose) on improved in vitro biomass yield in multiple shoot cultures of Centella asiatica. The back propagation neural network (BPNN) was employed to predict optimal biomass accumulation in terms of growth index over a defined culture duration of 35 days. The four variable concentrations of five media components, i.e. MgSO4 (0, 0.75, 1.5, 3.0 mM), ZnSO4 (0, 15, 30, 60 μM), CuSO4 (0, 0.05, 0.1, 0.2 μM), NO3 (20, 30, 40, 60 mM) and sucrose (1, 3, 5, 7 %, w/v) were taken as inputs for the ANN model. The designed model was evaluated by performing three different sets of validation experiments that indicated a greater similarity between the target and predicted dataset. The results of the modelling experiment suggested that 1.5 mM Mg, 30 μM Zn, 0.1 μM Cu, 40 mM NO3 and 6 % (w/v) sucrose were the respective optimal concentrations of the tested medium components for achieving maximum growth index of 1654.46 with high centelloside yield (62.37 mg DW/culture) in the cultured multiple shoots. This study can facilitate the generation of higher biomass of uniform, clean, good quality C. asiatica herb that can efficiently be utilized by pharmaceutical industries.

  14. Improved elastase production by Bacillus sp.EL31410--further optimization and kinetics studies of culture medium for batch fermentation

    Institute of Scientific and Technical Information of China (English)

    何国庆; 陈启和; 琚晓捷; 石乃冬

    2004-01-01

    An efficient culture medium producing a bacterial elastase with high yields was developed further following preliminary studies by means of response surface method. Central composite design (CCD) and response surface methodology were applied to optimize the medium constituents. A central composite design was used to explain the combined effect of three medium constituents, viz, glucose, K2HPO4, MgSO4@7H2O. The strain produced more elastase in the completely optimized medium, as compared with the partially optimized medium. The fitted model of the second model, as per RSM,showed that glucose was 7.4 g/100 ml, casein 1.13 g/100 ml, corn steep flour 0.616 g/100 ml, K2HPO4 0.206 g/100 ml and MgSO4@7H2O 0.034 g/100 ml. The fermentation kinetics of these two culture media in the flask experiments were analyzed. It was found that the highest elastase productivity occurred at 54 hours. Higher glucose concentration had inhibitory effect on elastase production. At the same time, we observed that the glucose consumption rate was slow in the completely optimized medium, which can explain the lag period of the highest elastase production. Some metal ions and surfactant additives also affected elastase production and cell growth.

  15. Aerosol generation and characterization of multi-walled carbon nanotubes exposed to cells cultured at the air-liquid interface.

    Science.gov (United States)

    Polk, William W; Sharma, Monita; Sayes, Christie M; Hotchkiss, Jon A; Clippinger, Amy J

    2016-04-23

    Aerosol generation and characterization are critical components in the assessment of the inhalation hazards of engineered nanomaterials (NMs). An extensive review was conducted on aerosol generation and exposure apparatus as part of an international expert workshop convened to discuss the design of an in vitro testing strategy to assess pulmonary toxicity following exposure to aerosolized particles. More specifically, this workshop focused on the design of an in vitro method to predict the development of pulmonary fibrosis in humans following exposure to multi-walled carbon nanotubes (MWCNTs). Aerosol generators, for dry or liquid particle suspension aerosolization, and exposure chambers, including both commercially available systems and those developed by independent researchers, were evaluated. Additionally, characterization methods that can be used and the time points at which characterization can be conducted in order to interpret in vitro exposure results were assessed. Summarized below is the information presented and discussed regarding the relevance of various aerosol generation and characterization techniques specific to aerosolized MWCNTs exposed to cells cultured at the air-liquid interface (ALI). The generation of MWCNT aerosols relevant to human exposures and their characterization throughout exposure in an ALI system is critical for extrapolation of in vitro results to toxicological outcomes in humans.

  16. The evaluation of kefir pure culture starter: Liquid-core capsule entrapping microorganisms isolated from kefir grains.

    Science.gov (United States)

    Wang, Liang; Zhong, Hao; Liu, Keying; Guo, Aizhen; Qi, Xianghui; Cai, Meihong

    2016-10-01

    The main purpose of this study was to develop a pure culture starter for producing kefir. In order to accomplish starter recycling, yeasts (Kluyveromyces marxianus strain, Pichia kudriavzevii clone), lactic acid bacteria (Lactobacillus kefiri strain F4Aa, Lactobacillus kefiri strain NM131-7, Lactobacillus kefiri strain NM132-3, Lactobacillus kefiri strain NM180-3, respectively), and acetic acid bacteria (Acetobacter lovaniensis strain) were entrapped in liquid core capsules based on the distribution ratio in kefir grains. The microbiological, antimicrobial, and chemical properties of kefir made with capsules (M) and kefir grains (K) were measured and compared. According to the results of plate counts in different selective medium, the number of yeasts and bacteria in the liquid core capsules gradually increased and stabilized after eight fermentation cycles. The results of gas chromatography-mass spectrometry showed that almost all the aroma components existed in the two type of kefir, except the ethyl lactate. There was no significant difference in alcohol content, protein content, and fat content, except the acidity and sugar content. Water holding capacity of kefir K was higher than kefir M. There were 14 same free amino acids in kefir M and kefir K, and the content of most free amino acids was similar. In antimicrobial test, there was no significant difference in both kefirs. © The Author(s) 2016.

  17. Optimized Dispersive Liquid-Liquid Microextraction Method and High Performance Liquid Chromatography with Ultraviolet Detection for Simultaneous Determination of Sorbic and Benzoic Acids and Evaluation of Contamination of These Preservatives in Iranian Foods.

    Science.gov (United States)

    Javanmardi, Fardin; Arefhosseini, Seyyed Rafie; Ansarin, Masood; Nemati, Mahboob

    2015-01-01

    A rapid, simple, and sensitive dispersive liquid-liquid microextraction procedure followed by HPLC-UV was applied to determine the benzoate and sorbate in foods. The method was optimized for some variables including extraction solvent type and volume, dispersing solvent type and volume, and the effects of salt and pH. Optimum conditions were determined as follows: sample volume, 5 mL; extraction solvent (chloroform) volume, 250 μL; disperser solvent (acetone) volume, 1.2 mL; NaCl amount, 0.75 g/5 mL at pH 4. Sixty samples were analyzed, including 15 doogh, 15 fruit juice, 15 cookie, and 15 tomato paste; benzoic acid was detected in 57 samples (95%) at levels up to 448.1 μg/mL and sorbic acid in 31 samples (51.6%) at levels up to 1369 μg/mL. Under the optimum experimental conditions, the LOD and LOQ were determined as 0.1 and 0.5 μg/mL for benzoate and 0.08 and 0.3 μg/mL for sorbate, respectively. The results showed that these preservatives are commonly used at high levels in yogurt drinks (dooghs) and cookies. Also, the concentration of benzoic acid that was detected in the tomato paste and fruit juice samples was low but may affect children and sensitive persons.

  18. Optimization of a Liquid Crystal-based Sensory Platform for Monitoring Enzymatic Glucose Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yibin; Jang, Chang-Hyun [Gachon University, Seongnam (Korea, Republic of)

    2016-05-15

    Managing glucose levels in human blood is extremely important for the treatment of diabetes. Here, an innovative sensory strategy has been developed to monitor the enzymatic activities of glucose and glucose oxidase by using confined liquid crystal (LC) birefringent droplet patterns. Acidic products released during the glucose oxidation process lead to a slight decrease in the pH of aqueous systems that can be monitored by pH-sensitive LC materials. Of the existing pH-sensitive LC materials, dodecanoic acid-doped 4-cyano-4'-pentylbiphenyl is inexpensive and easily adjusted to satisfy the 7.4 ± 0.05 pH requirement of human blood. Moreover, the orientational alignment of capillary-confined pH-responsive LCs can be disrupted at the aqueous/LC interface following a slight decrease in the critical pH of aqueous reaction systems, which results in an optical signal that can be observed with the naked eye by using polarizing optical microscopy. Based on the stable LC droplet patterns generated by the cylindrical confinement system, the functionalized LCs can selectively detect glucose at concentrations as low as 0.1 pM. This study further advances the previously reported LC-based glucose monitoring systems by reducing production costs and instituting a smarter LC sensory design. This improved system shows potential for the use in clinical bioassay applications.

  19. Decline Curve Analysis for Production Forecast and Optimization of Liquid-Dominated Geothermal Reservoir

    Science.gov (United States)

    Hidayat, I.

    2016-09-01

    Power projects in the geothermal field has a long span of about 30 years. The power supply should be maintained at a certain value across a range of time. A geothermal field, however, has the characteristics of natural production decline with time. In a geothermal field, development of decline curve model of steam production is important for forecasting production decline in the future. This study was developed using decline curve by production data along 3 years liquid-dominated geothermal reservoir in Ulubelu field. Decline curve in geothermal field based on decline curve in petroleum industry. The decline curve was correlated by reservoir management in geothermal. The purposes of this study to get best match model decline curve and forecasting production in the future. Based on decline curve analysis by production data in Ulubelu field, the result model decline curve is exponential model. From the model, we can get the value of decline rate in the field is 9.4 %/year. Then, the formula of forecasting steam flow used exponent decline to forecast in the future. By using separated system cycle in Ulubelu field, the minimal steam flowrate towards turbine was 502018.4 ton/month. Based on formula of forecasting production and minimal steam flowrate, we can get the time make up wells to maintain steam supply for stability in generator power capacity.

  20. Experimental Investigation and Optimization of Solid Suspension in Non-Newtonian Liquids at High Solid Concentration

    Directory of Open Access Journals (Sweden)

    Roozbeh Mollaabbasi

    2016-01-01

    Full Text Available This research deals with experimental work on solid suspension and dispersion in stirred tank reactors that operate with complex fluids. Only suspended speed (Njs throughout the vessel was characterized using Gamma-Ray Densitometry. The outcomes of this study help to understand solid suspension mechanisms involving changes the rheology of the fluid and provide engineering data for designing stirred tanks. All experiments were based on classic radial and axial flow impellers, i.e., Rushton Turbine (RT and Pitched Blade Turbine in down pumping mode (PBT-D. Three different liquids (water, water+CMC, and water+PAA were employed in several concentrations. The CMC solution introduced as a pseudo plastic fluid and PAA solution was applied as a Herschel Bulkley fluid. The rheological properties of these fluids were characterized separately. According to the findings, the critical impeller speeds for solid suspension for non-Newtonian fluids were more eminent than those for water. Experiments were performed to characterize the effects of solid loading, impeller clearance and viscosity on Njs. Also the PSO method is employed to find suitable parameters of Zwietering's correlation for prediction of Njs in Non Newtonian fluids.

  1. Ultrasonic Assisted Extraction of Paclitaxel from Taxus x media Using Ionic Liquids as Adjuvants: Optimization of the Process by Response Surface Methodology.

    Science.gov (United States)

    Tan, Zhijian; Li, Qiao; Wang, Chaoyun; Zhou, Wanlai; Yang, Yuanru; Wang, Hongying; Yi, Yongjian; Li, Fenfang

    2017-09-11

    (1) Background: Ionic liquids (ILs) are considered "green" solvents and have been widely used in the extraction and separation field in recent years; (2) Methods: In this study, some common ILs and functionalized magnetic ionic liquids (MILs) were used as adjuvants for the solvent extraction of paclitaxel from Taxus x media (T. x media) using methanol solution. The extraction conditions of methanol concentration, IL type and amount, solid-liquid ratio, extraction temperature, and ultrasonic irradiation time were investigated in single factor experiments. Then, three factors of IL amount, solid-liquid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM); (3) Results: The MIL [C₄MIM]FeCl₃Br was screened as the optimal adjuvant. Under the optimization conditions of 1.2% IL amount, 1:10.5 solid-liquid ratio, and 30 min ultrasonic irradiation time, the extraction yield reached 0.224 mg/g; and (4) Conclusions: Compared with the conventional solvent extraction, this ultrasonic assisted extraction (UAE) using methanol and MIL as adjuvants can significantly improve the extraction yield, reduce the use of methanol, and shorten the extraction time, which has the potentiality of being used in the extraction of some other important bioactive compounds from natural plant resources.

  2. Optimization

    CERN Document Server

    Pearce, Charles

    2009-01-01

    Focuses on mathematical structure, and on real-world applications. This book includes developments in several optimization-related topics such as decision theory, linear programming, turnpike theory, duality theory, convex analysis, and queuing theory.

  3. Liquid Culture of Adventitious Roots is a Potential Alternative to Field Cultivation for Psammosilene tunicoides, a Rare and Endangered Endemic Medicinal Plant

    Directory of Open Access Journals (Sweden)

    Zongshen Zhang

    2013-02-01

    Full Text Available The aim of this study was to establish an adventitious roots culture system for sterile plantlet segments of P. tunicoides and improved the accumulation of total saponins in cultured roots. Psammosilene tunicoides is a native Chinese plant with high commercial value as medicinal herb. Combination of NAA and IBA significantly affected the adventitious roots formation on agar-solided B5 media and a maximal induction rate of 83% was obtained at 24±2°C with a photoperiod of 12 h. With a shaking of 110 rpm in darkness, transferring the detached adventitious roots to the growth regulator free 1/2 B5 liquid media notably increased the biomass production compared to that on solid media over a 30-day-culture period. Further analyses showed that more saponins could be accumulated in the liquid culture than in the solid culture and the addition of exogenous oxalic acid to the liquid media could enhance the accumulation of total saponins in adventitious roots. These results suggested that adventitious roots culture will be an efficient alternative to the field cultivation of intact plants for the production of useful natural compounds from P. tunicoides.

  4. Adolescent Autonomy-Relatedness and the Family in Cultural Context: What Is Optimal?

    Science.gov (United States)

    Kagitcibasi, Cigdem

    2013-01-01

    This review examines self-family-culture links from a cultural and global perspective utilizing Kagitcibasi's Family Change Theory and Self Theory as general frameworks. These theories have the "autonomous-related self" at their point of intersection. Autonomy and relatedness dynamics is the key to understanding the self, and family…

  5. Speciation of vanadium in oilsand coke and bacterial culture by high performance liquid chromatography inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. Sherry [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Le, X. Chris [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada)], E-mail: xc.le@ualberta.ca

    2007-10-17

    A simple and sensitive method for the speciation of vanadium(III), (IV), and (V) was developed by using high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICPMS). The EDTA-complexed vanadium species were separated on a strong anion exchange column with an eluent containing 2 mM EDTA, 3% acetonitrile, and 80 mM ammonium bicarbonate at pH 6. Each analysis was complete in 5 min. The detection limits were 0.6, 0.7 and 1.0 {mu}g L{sup -1} for V(III), V(IV), and V(V), respectively. The method was applied to coke pore water samples from an oilsand processing/upgrading site in Fort McMurray, Alberta, Canada and to Shewanella putrefaciens CN32 bacterial cultures incubated with V(V). In the coke pore water samples, V(IV) and V(V) were found to be the major species. For the first time, V(III) was detected in the bacterial cultures incubated with V(V)

  6. HEK293 cell culture media study towards bioprocess optimization: Animal derived component free and animal derived component containing platforms.

    Science.gov (United States)

    Liste-Calleja, Leticia; Lecina, Martí; Cairó, Jordi Joan

    2014-04-01

    The increasing demand for biopharmaceuticals produced in mammalian cells has lead industries to enhance bioprocess volumetric productivity through different strategies. Among those strategies, cell culture media development is of major interest. In the present work, several commercially available culture media for Human Embryonic Kidney cells (HEK293) were evaluated in terms of maximal specific growth rate and maximal viable cell concentration supported. The main objective was to provide different cell culture platforms which are suitable for a wide range of applications depending on the type and the final use of the product obtained. Performing simple media supplementations with and without animal derived components, an enhancement of cell concentration from 2 × 10(6) cell/mL to 17 × 10(6) cell/mL was achieved in batch mode operation. Additionally, the media were evaluated for adenovirus production as a specific application case of HEK293 cells. None of the supplements interfered significantly with the adenovirus infection although some differences were encountered in viral productivity. To the best of our knowledge, the high cell density achieved in the work presented has never been reported before in HEK293 batch cell cultures and thus, our results are greatly promising to further study cell culture strategies in bioreactor towards bioprocess optimization. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Optimization of fluorescence detection for polyaromatic hydrocarbon determination by using high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, P.J.; Carpenter, P.D.; Brady, P.H.; McCormick, M.J.; Griffiths, A.J.; Hatvani, T.S.G.; Rasdell, S.G. (Royal Melbourne Inst. of Tech., Victoria (Australia))

    1993-01-01

    Polyaromatic hydrocarbon determination is often one of the requirements in site evaluations and chemical audit studies, particularly where the site usage is to change from industrial to recreational or domestic housing. It is also a general parameter included in air particulate studies and water quality evaluations in the urban environment, where PAHs accumulate as a result of vehicle and industrial emissions. The procedures needed for the optimization of programmable fluorescence detectors have been investigated. The authors found that wavelength programs had to be developed from data obtained from the particular detector for which the program was to be used--programs reported in the literature or developed from data obtained on other instruments gave substantially lower sensitivities. The wavelength program they developed was a compromise between: chromatographic separation, abundance and relative sensitivity of each PAH; the ease with which a timed event could be included in the elution profile and; the relative importance of each PAH to the analyst. The success of programmable fluorescence detection was dependant on the reproducibility with which the detector was able to reset specified wavelengths, with corresponding detector response variability of up to 20% for one new detector.

  8. Mycobacterial DNA extraction for whole-genome sequencing from early positive liquid (MGIT) cultures.

    Science.gov (United States)

    Votintseva, Antonina A; Pankhurst, Louise J; Anson, Luke W; Morgan, Marcus R; Gascoyne-Binzi, Deborah; Walker, Timothy M; Quan, T Phuong; Wyllie, David H; Del Ojo Elias, Carlos; Wilcox, Mark; Walker, A Sarah; Peto, Tim E A; Crook, Derrick W

    2015-04-01

    We developed a low-cost and reliable method of DNA extraction from as little as 1 ml of early positive mycobacterial growth indicator tube (MGIT) cultures that is suitable for whole-genome sequencing to identify mycobacterial species and predict antibiotic resistance in clinical samples. The DNA extraction method is based on ethanol precipitation supplemented by pretreatment steps with a MolYsis kit or saline wash for the removal of human DNA and a final DNA cleanup step with solid-phase reversible immobilization beads. The protocol yielded ≥0.2 ng/μl of DNA for 90% (MolYsis kit) and 83% (saline wash) of positive MGIT cultures. A total of 144 (94%) of the 154 samples sequenced on the MiSeq platform (Illumina) achieved the target of 1 million reads, with 90% coverage achieved. The DNA extraction protocol, therefore, will facilitate fast and accurate identification of mycobacterial species and resistance using a range of bioinformatics tools. Copyright © 2015, Votintseva et al.

  9. COMPARISON OF POLYSACCHARIDES ISOLATED FROM THE MYCELIA OF A CULTIVATED STRAIN OF PORIA COCOS GROWN IN DIFFERENT LIQUID CULTURE MEDIA

    Institute of Scientific and Technical Information of China (English)

    Li-na Zhang; Li Chen; Yong Jin; Yu-lu Lin; Peter Chi Keung Cheung; Li-guo Chen

    2003-01-01

    Mycelium of a cultivated strain of Poria cocos was grown by submerged fermentation in a liquid medium containing com steep liquor with orbital shaking. Six polysaccharides coded as ac-PCM 1, ac-PCM2, ac-PCM3-I and II, acPCM4-I and II were isolated from the mycelium by extracting with 0.9% NaC1 aqueous solution, hot water, 0.5 mol/L NaOH aqueous solution and 88% formic acid. Exo-polysaccharide was obtained from the culture medium and coded as ac-PCM0.The monosaccharide composition and molecular weights of these polysaccharides were characterized by using infrared spectroscopy, gas chromatography, elemental analysis, 13C-NMR, viscometry and light scattering. The results indicated that ac-PCM0, ac-PCM1 and ac-PCM2 are heteropolysaccharides containing glucose, galactose, mannose and fucose, and acPCM3-I and ac-PCM3-II mainly consist of D-glucose. The content of the glucose in the polysaccharides increased with the isolation progress. Remarkably, a-glucan and β-glucan coexisted in the extract by NaOH aqueous solution (ac-PCM3), and could be separated by chemical methods. The protein in the ac-PCM polysaccharides cultured from the medium containing com steep liquor was higher than that in the ab-PCM from the medium with bran extract. Therefore, the polysaccharides from Poria cocos mycelia cultured in different media have different chemical composition, molecular weights and conformations.

  10. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    Science.gov (United States)

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. Copyright © 2014 The British Mycological Society. All rights reserved.

  11. Elm tree (Ulmus parvifolia) bark bioprocessed with Mycelia of Shiitake (Lentinus edodes) mushrooms in liquid Culture: Composition and mechanism of protection against allergic asthma in mice

    Science.gov (United States)

    The present study investigated the antiasthma effect of a bioprocessed Ulmus parvifolia bark extract (BPUBE) from Lentinus edodes liquid mycelia culture against allergic asthma biomarkers in U266B1 leukemia cells and OVA-sensitized/challenged mice. BPUBE suppressed total IgE release from U266B1 cel...

  12. Optimal feed rate profiles for fed-batch culture in penicillin production

    Directory of Open Access Journals (Sweden)

    Murray Moo-Young

    2005-09-01

    Full Text Available The fed-batch optimization of penicillin productivity was applied as an example of optimization algorithm verification. The objective function of this problem was to optimize penicillin productivity by determination of feed rate trajectory. This study compared the optimized results derived from the proposed algorithm and from the iterative dynamic programming. Three decision variables for the proposed algorithm comprised ts (switching time from exponential to linear feeding schedules, K (constant in feed rate equation, and ε (a multiplier on substrate requirement. Estimation of this set of decision variables employed Markov chain Monte Carlo procedures (the Gibbs parameter sampling and the Metropolis-Hasting algorithm using an originally given set of initial values. The optimization procedure was divided into two time periods as follows: i the time period of exponential feeding policy, t ts. The calculation procedure of the first period of fermentation time had been proposed by integrating Pontryagin’s optimum principle and Luedeking-Piret equation. The feed rate profile during the later period was obtained from the direct substitution of desired substrate requirement derived from Monod equation. The optimal feed-rate profile corresponded to the values of decision variables as follows [ts K ε] = [35.9370.096 2.087]. The proposed algorithm was appropriate for determination of optimal feed-rate trajectories in any fed-batch problems provided that the product formation rate agrees with a Luedecking-Piret model.

  13. Purification and germination of Candida albicans and Candida dubliniensis chlamydospores cultured in liquid media.

    LENUS (Irish Health Repository)

    Citiulo, Francesco

    2009-10-01

    Candida albicans and Candida dubliniensis are the only Candida sp. that have been observed to produce chlamydospores. The function of these large, thick-walled cells is currently unknown. In this report, we describe the production and purification of chlamydospores from these species in defined liquid media. Staining with the fluorescent dye FUN-1 indicated that chlamydospores are metabolically active cells, but that metabolic activity is undetectable in chlamydospores that are >30 days old. However, 5-15-day-old chlamydospores could be induced to produce daughter chlamydospores, blastospores, pseudohyphae and true hyphae depending on the incubation conditions used. Chlamydospores that were preinduced to germinate were also observed to escape from murine macrophages following phagocytosis, suggesting that these structures may be viable in vivo. Mycelium-attached and purified chlamydospores rapidly lost their viability in water and when subjected to dry stress, suggesting that they are unlikely to act as long-term storage structures. Instead, our data suggest that chlamydospores represent an alternative specialized form of growth by C. albicans and C. dubliniensis.

  14. Final report-passive safety optimization in liquid sodium-cooled reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Cahalana, J. E.; Hahn, D.; Nuclear Engineering Division; Korea Atomic Energy Research Inst.

    2007-08-13

    This report summarizes the results of a three-year collaboration between Argonne National Laboratory (ANL) and the Korea Atomic Energy Research Institute (KAERI) to identify and quantify the performance of innovative design features in metallic-fueled, sodium-cooled fast reactor designs. The objective of the work was to establish the reliability and safety margin enhancements provided by design innovations offering significant potential for construction, maintenance, and operating cost reductions. The project goal was accomplished with a combination of advanced model development (Task 1), analysis of innovative design and safety features (Tasks 2 and 3), and planning of key safety experiments (Task 4). Task 1--Computational Methods for Analysis of Passive Safety Design Features: An advanced three-dimensional subassembly thermal-hydraulic model was developed jointly and implemented in ANL and KAERI computer codes. The objective of the model development effort was to provide a high-accuracy capability to predict fuel, cladding, coolant, and structural temperatures in reactor fuel subassemblies, and thereby reduce the uncertainties associated with lower fidelity models previously used for safety and design analysis. The project included model formulation, implementation, and verification by application to available reactor tests performed at EBR-II. Task 2--Comparative Analysis and Evaluation of Innovative Design Features: Integrated safety assessments of innovative liquid metal reactor designs were performed to quantify the performance of inherent safety features. The objective of the analysis effort was to identify the potential safety margin enhancements possible in a sodium-cooled, metal-fueled reactor design by use of passive safety mechanisms to mitigate low-probability accident consequences. The project included baseline analyses using state-of-the-art computational models and advanced analyses using the new model developed in Task 1. Task 3--Safety

  15. Single Cell Protein Production by Saccharomyces cerevisiae Using an Optimized Culture Medium Composition in a Batch Submerged Bioprocess.

    Science.gov (United States)

    Hezarjaribi, Mehrnoosh; Ardestani, Fatemeh; Ghorbani, Hamid Reza

    2016-08-01

    Saccharomyces cerevisiae PTCC5269 growth was evaluated to specify an optimum culture medium to reach the highest protein production. Experiment design was conducted using a fraction of the full factorial methodology, and signal to noise ratio was used for results analysis. Maximum cell of 8.84 log (CFU/mL) was resulted using optimized culture composed of 0.3, 0.15, 1, and 50 g L(-1) of ammonium sulfate, iron sulfate, glycine, and glucose, respectively at 300 rpm and 35 °C. Glycine concentration (39.32 % contribution) and glucose concentration (36.15 % contribution) were determined as the most effective factors on the biomass production, while Saccharomyces cerevisiae growth had showed the least dependence on ammonium sulfate (5.2 % contribution) and iron sulfate (19.28 % contribution). The most interaction was diagnosed between ammonium sulfate and iron sulfate concentrations with interaction severity index of 50.71 %, while the less one recorded for glycine and glucose concentration was equal to 8.12 %. An acceptable consistency of 84.26 % was obtained between optimum theoretical cell numbers determined by software of 8.91 log (CFU/mL), and experimentally measured one at optimal condition confirms the suitability of the applied method. High protein content of 44.6 % using optimum culture suggests that Saccharomyces cerevisiae is a good commercial case for single cell protein production.

  16. Optimization of culturing condition and medium composition for the production of alginate lyase by a marine Vibrio sp. YKW-34

    Science.gov (United States)

    Fu, Xiaoting; Lin, Hong; Kim, Sang Moo

    2008-02-01

    Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened, and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL-1. The best inoculum volume and inoculum age were 10% and 12 h, respectively. The optimal temperature for alginate lyase production was 25°C. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.

  17. Optimization of Culturing Condition and Medium Composition for the Production of Alginate Lyase by a Marine Vibrio sp. YKW-34

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened,and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL-1. The best inoculum volume and inoculum age were 10% and 12 h, respectively. The optimal temperature for alginate lyase production was 25℃. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.

  18. Combined use of GAP and AOX1 promoters and optimization of culture conditions to enhance expression of Rhizomucor miehei lipase.

    Science.gov (United States)

    He, Dong; Luo, Wen; Wang, Zhiyuan; Lv, Pengmei; Yuan, Zhenhong

    2015-08-01

    Rhizo mucor miehei lipase (RML) is an industrially important enzyme, but its application is limited due to its high cost. In this study, a series of measures such as codon optimization, propeptide addition, combined use of GAP and AOX1 promoters, and optimization of culture conditions were employed to increase the expression of RML. Three transformants of the constitutive-inducible combined Pichia pastoris strains were generated by transforming the pGAPZαA-rml vector into the pPIC9K-rml/GS115 strain, which resulted in high-expression yields of RML. Using the shake flask method, highest enzyme activity corresponding to 140 U/mL was observed in the strain 3-17, which was about sixfold higher than that of pPIC9K-rml/GS115 or pGAPZαA-rml/GS115. After optimization of culture conditions by response surface methodology, the lipolytic activity of strain 3-17 reached 175 U/mL in shake flasks. An increase in the copy number simultaneously with the synergistic effect provided by two promoters led to enhanced degree of protein expression.

  19. Use of response surface design in the optimization of starter cultures ...

    African Journals Online (AJOL)

    Admin

    2013-05-08

    May 8, 2013 ... starter cultures for enhanced rhamnolipid production .... The primary inoculum was prepared by transferring a loopful of bacteria from the slant to 250 ..... Effect of inoculation methods on the composting efficiency of municipal ...

  20. Optimizing the culture environment and embryo manipulation to help maintain embryo developmental potential.

    Science.gov (United States)

    Swain, Jason E; Carrell, Doug; Cobo, Ana; Meseguer, Marcos; Rubio, Carmen; Smith, Gary D

    2016-03-01

    With increased use of comprehensive chromosome screening (CCS), the question remains as to why some practices do not experience the same high levels of clinical success after implementation of the approach. Indeed, the debate surrounding the efficacy and usefulness of blastocyst biopsy and CCS continues. Importantly, several variables impact the success of an assisted reproductive technology cycle. Transfer of a euploid embryo is but one factor in an intricate system that requires numerous steps to occur successfully. Certainly, the culture environment and the manipulations of the embryo during its time in the laboratory can impact its reproductive potential. Environmental stressors ranging from culture media to culture conditions and even culture platform can impact biochemical, metabolic, and epigenetic patterns that can affect the developing cell independent of chromosome number. Furthermore, accompanying procedures, such as biopsy and vitrification, are complex and, when performed improperly, can negatively impact embryo quality. These are areas that likely still carry room for improvement within the IVF laboratory.

  1. Finite-difference time-domain analysis of a complete transverse electromagnetic cell loaded with liquid biological media in culture dishes.

    Science.gov (United States)

    Popović, M; Hagness, S C; Taflove, A

    1998-08-01

    Transverse electromagnetic (TEM) cells can be used for exposing biological culture specimens to electromagnetic fields and observing possible anomalous effects. The uniformity of field exposure is critical to quantifying the biological response versus the electromagnetic dose. Standing waves and other electromagnetic field nonuniformities can cause nonuniform exposure. This paper reports the results of high-resolution three-dimensional finite-difference time-domain (FDTD) simulations of a complete TEM cell designed for operation at 837 MHz. Several different cases were studied in which the number of culture dishes, the depth of the culture liquid, and the orientation of the culture dishes were varied. Further, the effect of the culture-dish glass bottom thickness and the meniscus of the liquid medium were examined. The FDTD results show that there is a significant nonuniform field and specific absorption rate (SAR) distribution within the culture medium for each case examined. Hence, biological dose-response experiments using the TEM cells should account for the possibility of strong localized SAR peaking in the culture media to provide useful data in setting exposure standards for wireless communications.

  2. Optimization of callus and cell suspension cultures of Barringtonia racemosa (Lecythidaceae family) for lycopene production

    OpenAIRE

    Behbahani, Mandana; Shanehsazzadeh, Mehrnaz; Hessami,Mohamad Javad

    2011-01-01

    Lycopene is present in a range of fresh fruits and vegetables, especially in the leaves of Barringtonia racemosa. The traditional lycopene extraction from the plant is being employed instead of an easy propagation technique like cell culture process from the leaf explants. We intend to assess how lycopene could be extracted via tissue culture under light (illuminance: 8,200 lux under white fluorescent lamps, photoperiod 16 h per day at 25ºC) and dark. Leaf explants of Barringtonia racemosa we...

  3. Isolation and analysis of differentially expressed genes during asexual sporulation in liquid static culture of Ganoderma lucidum by suppression subtractive hybridization.

    Science.gov (United States)

    Xu, Jun-Wei; Zhao, Wei; Xu, Yi-Ning; Zhong, Jian-Jiang

    2012-04-01

    Ganoderma lucidum differentiates in liquid static culture by forming aerial mycelia and asexual spores, and this differentiation process is accompanied by higher production of anti-tumor compounds ganoderic acids. To gain an insight into the molecular events during asexual sporulation of G. lucidum, comparative transcriptome analysis using suppression subtractive hybridization (SSH) technique was performed to identify preferentially expressed genes in liquid static culture vs. in traditional shaking culture. After macroarray analysis of 1920 cDNAs from SSH library, 147 unigenes which exhibited high expression in static culture were identified. Among these sequences, putative translations of 88 unigenes possessed much similarity to known proteins involved in cell organization, signal transduction, cell metabolism, protein biosynthesis and transcription regulation; 13 had significant similarity to hypothetical proteins; the remaining 46 showed little or no similarity to GenBank sequences. RT-qPCR analysis confirmed increases in transcripts of selected genes under liquid static culture condition. The results of this study present the useful application of EST analysis on G. lucidum and provide preliminary indication of gene expression putatively involved in asexual sporulation process.

  4. Fabrication and optimization of alginate hydrogel constructs for use in 3D neural cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Frampton, J P; Hynd, M R; Shain, W [Department of Biomedical Sciences, School of Public Health, State University of New York at Albany, Albany, NY 12210 (United States); Shuler, M L, E-mail: jf7674@albany.edu [Department of Biomedical Engineering, 270 Olin Hall, Cornell University, Ithaca, NY 14850 (United States)

    2011-02-15

    Two-dimensional (2D) culture systems provide useful information about many biological processes. However, some applications including tissue engineering, drug transport studies, and analysis of cell growth and dynamics are better studied using three-dimensional (3D) culture systems. 3D culture systems can potentially offer higher degrees of organization and control of cell growth environments, more physiologically relevant diffusion characteristics, and permit the formation of more extensive 3D networks of cell-cell interactions. A 3D culture system has been developed using alginate as a cell scaffold, capable of maintaining the viability and function of a variety of neural cell types. Alginate was functionalized by the covalent attachment of a variety of whole proteins and peptide epitopes selected to provide sites for cell attachment. Alginate constructs were used to entrap a variety of neural cell types including astroglioma cells, astrocytes, microglia and neurons. Neural cells displayed process outgrowth over time in culture. Cell-seeded scaffolds were characterized in terms of their biochemical and biomechanical properties, effects on seeded neural cells, and suitability for use as 3D neural cell culture models.

  5. 桑黄液体发酵培养条件和多糖提取工艺的优化%Optimization of Liquid Fermentation Conditions of Phellinus linteus and Mycel ial Polysaccharide Extraction Process

    Institute of Scientific and Technical Information of China (English)

    杨成凤; 郑凌君; 廖尊胜; 刘晓艳; 吕旭聪; 林占熺; 黄一帆; 赵超; 刘斌

    2015-01-01

    The culture conditions of solid and liquid fermentation of Phellinus linteus and mycelial polysaccharide extraction process are optimized.The result shows that the optimal carbon sources for liquid fermentation medium are corn powder and soybean powder and the optimal nitrogen sources are yeast extract and soybean powder,the best ratio of carbon to nitrogen is 25∶1,temperature is 28 ℃, liquid medium volume is 80 mL,rotating speed is 1 10 r/min,and fermentation time is 9 days.While Pennisetum sinese as the main base material is cultivated by solid fermentation,P .linteus mycelium grows well.The optimal fermentation conditions for P .linteus mycelium fermented with P .sinese are as follows:extraction temperature of 90 ℃,solid-liquid ratio of 1∶40,extraction time of 1.5 h, with 3 times-volume ethanol alcohol polysaccharide,under the above conditions,the polysaccharide yield reaches 12.06%,which has more mycelium polysaccharides than other cultivation methods.%对桑黄固体和液体发酵培养条件及菌丝多糖的提取工艺进行优化。结果表明:桑黄液体发酵培养基的最佳碳源是玉米粉和黄豆粉,最佳氮源是酵母浸出汁和黄豆粉,最佳碳氮比25∶1,温度28℃,装液量80 mL,转速110 r/min,发酵培养时间9天。以巨菌草为主要基料进行固体发酵培养,桑黄菌丝长势良好。巨菌草发酵培养的桑黄菌丝多糖的最佳提取工艺为温度90℃,料液比1∶40,提取时间1.5 h,以3倍体积的乙醇醇沉多糖的条件下多糖得率最高,达到12.06%,高于其他栽培方式的桑黄菌丝体多糖含量。

  6. Development of optimal liquid based cytology sample processing methods for HPV testing: minimising the 'inadequate' test result.

    Science.gov (United States)

    Peevor, R; Jones, J; Fiander, A N; Hibbitts, S

    2011-05-01

    Incorporation of HPV testing into cervical screening is anticipated and robust methods for DNA extraction from liquid based cytology (LBC) samples are required. This study compared QIAamp extraction with Proteinase K digestion and developed methods to address DNA extraction failure (β-globin PCR negative) from clinical specimens. Proteinase K and QIAamp extraction methods in paired LBC samples were comparable with adequate DNA retrieved from 93.3% of clinical specimens. An HPV prevalence cohort (n=10,000) found 7% (n=676) LBC samples tested negative for β-globin, and were classified as inadequate. This 'failure' rate is unsuitable for population screening, particularly as the sampling method is intrusive. 379/676 samples were assessed to determine the cause of test failure. Re-testing confirmed adequate DNA in 21.6% of the original extracts; re-extraction from stored material identified 56.2% samples contained adequate material; dilution to overcome sample inhibition (1:10) resolved 51.7% cases in original extracts and 28% in new extracts. A standardised approach to HPV testing with an optimal DNA concentration input rather than standard volume input is recommended. Samples failing initial DNA extraction should be repeat extracted and assessed for sample inhibition to reduce the 7% of HPV tests being reported as inadequate and reduce the need for retesting of those women to <1%.

  7. Optimization of PEDOT films in ionic liquid supercapacitors: demonstration as a power source for polymer electrochromic devices.

    Science.gov (United States)

    Österholm, Anna M; Shen, D Eric; Dyer, Aubrey L; Reynolds, John R

    2013-12-26

    We report on the optimization of the capacitive behavior of poly(3,4-ethylenedioxythiophene) (PEDOT) films as polymeric electrodes in flexible, Type I electrochemical supercapacitors (ESCs) utilizing ionic liquid (IL) and organic gel electrolytes. The device performance was assessed based on figures of merit that are critical to evaluating the practical utility of electroactive polymer ESCs. PEDOT/IL devices were found to be highly stable over hundreds of thousands of cycles and could be reversibly charged/discharged at scan rates between 500 mV/s and 2 V/s depending on the polymer loading. Furthermore, these devices exhibit leakage currents and self-discharge rates that are comparable to state of the art electrochemical double-layer ESCs. Using an IL as device electrolyte allowed an extension of the voltage window of Type I ESCs by 60%, resulting in a 2.5-fold increase in the energy density obtained. The efficacies of tjese PEDOT ESCs were assessed by using them as a power source for a high-contrast and fast-switching electrochromic device, demonstrating their applicability in small organic electronic-based devices.

  8. Optimized ultra performance liquid chromatography tandem high resolution mass spectrometry method for the quantification of paraquat in plasma and urine.

    Science.gov (United States)

    Lu, Haihua; Yu, Jing; Wu, Linlin; Xing, Jingjing; Wang, Jun; Huang, Peipei; Zhang, Jinsong; Xiao, Hang; Gao, Rong

    2016-08-01

    A simple, sensitive and specific ultra performance liquid chromatography coupled to electrospray tandem high resolution mass spectrometry (UPLC-ESI-HRMS/MS) method has been developed and validated for quantification of paraquat in plasma and urine. The sample preparation was carried out by one-step protein precipitation with acetonitrile. The paraquat was separated with a HILIC column in 10min. Detection was performed using Q Exactive Orbitrap mass spectrometer by Targeted-MS/MS scan mode. Methodological parameters, such as ammonium formate concentration, formic acid concentration, spray voltage, capillary temperature, heater temperature and normalized collision energy were optimized to achieve the highest sensitivity. The calibration curve was linear over the concentration range of LOQ-1000ng/mL. LOD was 0.1 and 0.3ng/mL, LOQ was 0.3 and 0.8ng/mL for urine and plasma, respectively. The intra- and inter-day precisions were paraquat concentration in plasma samples with hemoperfusion from 5 suspected paraquat poisoning patients.

  9. Optimization of pressurized liquid extraction (PLE) of dioxin-furans and dioxin-like PCBs from environmental samples.

    Science.gov (United States)

    Antunes, Pedro; Viana, Paula; Vinhas, Tereza; Capelo, J L; Rivera, J; Gaspar, Elvira M S M

    2008-05-30

    Pressurized liquid extraction (PLE) applying three extraction cycles, temperature and pressure, improved the efficiency of solvent extraction when compared with the classical Soxhlet extraction. Polychlorinated-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like PCBs (coplanar polychlorinated biphenyls (Co-PCBs)) in two Certified Reference Materials [DX-1 (sediment) and BCR 529 (soil)] and in two contaminated environmental samples (sediment and soil) were extracted by ASE and Soxhlet methods. Unlike data previously reported by other authors, results demonstrated that ASE using n-hexane as solvent and three extraction cycles, 12.4 MPa (1800 psi) and 150 degrees C achieves similar recovery results than the classical Soxhlet extraction for PCDFs and Co-PCBs, and better recovery results for PCDDs. ASE extraction, performed in less time and with less solvent proved to be, under optimized conditions, an excellent extraction technique for the simultaneous analysis of PCDD/PCDFs and Co-PCBs from environmental samples. Such fast analytical methodology, having the best cost-efficiency ratio, will improve the control and will provide more information about the occurrence of dioxins and the levels of toxicity and thereby will contribute to increase human health.

  10. Optimization and development of a high-performance liquid chromatography-based one-site immunometric assay with chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Oates, Matthew R.; Clarke, William; Zimlich, Alden; Hage, David S

    2002-10-11

    Various practical and theoretical considerations were examined in the creation and optimization of a high-performance liquid chromatography (HPLC)-based one-site immunometric assay. This method used an HPLC analyte analog column and post-column chemiluminescence detection. The specific analyte chosen as the model for this study was L-thyroxine (also known as T{sub 4}). In this technique, a sample containing thyroxine was first combined with an excess of anti-T{sub 4} antibody Fab fragments that had earlier been conjugated with chemiluminescent acridinium ester labels. After incubation, the mixture was injected onto a column that contained immobilized T{sub 4}. The amount of thyroxine in the original sample was then determined by measuring the labeled Fab fragments that appeared in the non-retained fraction, or the decrease in excess Fab fragments that were bound to and later eluted from the column. Items considered in creating this assay included the preparation of acridinium ester-labeled Fab fragments, the detection of these fragments with a post-column reactor, and the creation of a suitable immobilized analog column for capturing excess labeled Fab fragments. The final method could measure T{sub 4} in standards at clinically-relevant concentrations and provided a response within 1.5 min of sample injection, following a 20-45 min incubation with the labeled Fab fragments. Possible applications of this method include its use in clinical chemistry and the screening of proteomic or combinatorial libraries.

  11. Effects of gangliosides on cell maturation of murine megakaryocytes in a liquid culture system.

    Science.gov (United States)

    Watanabe, Y; Taniguchi, M; Fukamachi, N; Sakuma, M; Kobayashi, B

    1990-04-01

    Formation of platelet-producing megakaryocytes, the cytoplasm of which showed the terminal stage of cell maturation, heavy granulation and platelet-fields delineated with demarcation membranes, was observed in a short-term culture system, using megakaryocyte-enriched bone marrow cell suspension. Approximately 6-8% of the megakaryocytes changed to the platelet-producing megakaryocytes during 12-hour incubation. In the presence of inhibitors of energy metabolism, formation of the platelet-producing megakaryocytes was inhibited, suggesting that the process is dependent on energy producing systems. Ganglioside GD1a increased both the number of total megakaryocytes and the ratio of the platelet-producing megakaryocytes to total megakaryocytes, while GM1 did not influence the number of total megakaryocytes, but increased the ratio. Gangliosides GM2, GM3 and GD1b showed little effect on either the number of total megakaryocytes or the ratio. The results suggest that ganglioside GD1a stimulates at least two steps of megakaryocyte maturation, the change of megakaryocytic progenitors to megakaryocytes and the subsequent maturation of megakaryocytes to the platelet-producing megakaryocytes, while GM1 stimulates only the latter step of the maturation.

  12. Modeling and optimization of glutamic acid production using mixed culture of Corynebacterium glutamicum NCIM2168 and Pseudomonas reptilivora NCIM2598.

    Science.gov (United States)

    Kumar, Rajaram Shyam; Moorthy, Innasi Muthu Ganesh; Baskar, Rajoo

    2013-01-01

    In this study, a hybrid system of response surface methodology followed by genetic algorithm has been adopted to optimize the production medium for L-glutamic acid fermentation with mixed cultures of Corynebacterium glutamicum and Pseudomonas reptilovora. The optimal combination of media components for maximal production of L-glutamic acid was found to be 49.99 g L(-1) of glucose, 10 g L(-1) of urea, 18.06% (v/v) of salt solution, and 4.99% (v/v) of inoculum size. The experimental glutamic acid yield at optimum condition was 19.69 g L(-1), which coincided well to the value predicted by the model (19.61 g L(-1)). Using this methodology, a nonlinear regression model was developed for the glutamic acid production. The model was validated statistically and the determination coefficient (R (2)) was found to be 0.99.

  13. Optimizing seeding and culture methods to engineer smooth muscle tissue on biodegradable polymer matrices.

    Science.gov (United States)

    Kim, B S; Putnam, A J; Kulik, T J; Mooney, D J

    1998-01-05

    The engineering of functional smooth muscle (SM) tissue is critical if one hopes to successfully replace the large number of tissues containing an SM component with engineered equivalents. This study reports on the effects of SM cell (SMC) seeding and culture conditions on the cellularity and composition of SM tissues engineered using biodegradable matrices (5 x 5 mm, 2-mm thick) of polyglycolic acid (PGA) fibers. Cells were seeded by injecting a cell suspension into polymer matrices in tissue culture dishes (static seeding), by stirring polymer matrices and a cell suspension in spinner flasks (stirred seeding), or by agitating polymer matrices and a cell suspension in tubes with an orbital shaker (agitated seeding). The density of SMCs adherent to these matrices was a function of cell concentration in the seeding solution, but under all conditions a larger number (approximately 1 order of magnitude) and more uniform distribution of SMCs adherent to the matrices were obtained with dynamic versus static seeding methods. The dynamic seeding methods, as compared to the static method, also ultimately resulted in new tissues that had a higher cellularity, more uniform cell distribution, and greater elastin deposition. The effects of culture conditions were next studied by culturing cell-polymer constructs in a stirred bioreactor versus static culture conditions. The stirred culture of SMC-seeded polymer matrices resulted in tissues with a cell density of 6.4 +/- 0.8 x 10(8) cells/cm3 after 5 weeks, compared to 2.0 +/- 1.1 x 10(8) cells/cm3 with static culture. The elastin and collagen synthesis rates and deposition within the engineered tissues were also increased by culture in the bioreactors. The elastin content after 5-week culture in the stirred bioreactor was 24 +/- 3%, and both the elastin content and the cellularity of these tissues are comparable to those of native SM tissue. New tissues were also created in vivo when dynamically seeded polymer matrices were

  14. Combination of Culture, Antigen and Toxin Detection, and Cytotoxin Neutralization Assay for Optimal Clostridium difficile Diagnostic Testing

    Directory of Open Access Journals (Sweden)

    Michelle J Alfa

    2013-01-01

    Full Text Available BACKGROUND: There has been a growing interest in developing an appropriate laboratory diagnostic algorithm for Clostridium difficile, mainly as a result of increases in both the number and severity of cases of C difficile infection in the past decade. A C difficile diagnostic algorithm is necessary because diagnostic kits, mostly for the detection of toxins A and B or glutamate dehydrogenase (GDH antigen, are not sufficient as stand-alone assays for optimal diagnosis of C difficile infection. In addition, conventional reference methods for C difficile detection (eg, toxigenic culture and cytotoxin neutralization [CTN] assays are not routinely practiced in diagnostic laboratory settings.

  15. Development of optimal medium content for bioelements accumulation in Bacopa monnieri (L.) in vitro culture.

    Science.gov (United States)

    Łojewski, Maciej; Muszyńska, Bożena; Smalec, Agata; Reczyński, Witold; Opoka, Włodzimierz; Sułkowska-Ziaja, Katarzyna

    2014-10-01

    Bacopa monnieri is one of the most interesting plants from the Ayurveda system. The aims of present research were, basing on in vitro shoot culture of B. monnieri, to determine content and to evaluate the influence of physiologically important metabolites on the selected bioelements accumulation in biomass. The most significant increase in biomass production was observed in the culture medium enriched with 0.5 mg/L of anthranilic acid. In this medium also, the highest accumulation of Mg was noted. The highest concentration of iron was determined in B. monnieri in vitro culture enriched with 0.25 g/L of serine. The addition of L-tryptophan, magnesium sulfate, and zinc hydroaspartate caused only a small increase in the accumulation of copper in B. monnieri. Increase in Zn accumulation was obtained in biomass from in vitro culture of B. monnieri with the addition of magnesium sulfate and zinc hydroaspartate. In the case of Na, the maximum level of this element was in biomass from medium enriched with zinc hydroaspartate. Twofold increase in K concentration was obtained in biomass from cultures on medium with addition of serine and magnesium sulfate. The concentrations of Ca in biomass of all studied media were at the similar level.

  16. Innovative use of Mucuna monosperma (Wight) callus cultures for continuous production of melanin by using statistically optimized biotransformation medium.

    Science.gov (United States)

    Inamdar, Shrirang; Joshi, Swati; Bapat, Vishwas; Jadhav, Jyoti

    2014-01-20

    Melanins are predominantly indolic polymers which are having extensive applications in cosmetics, agriculture and medicine. In the present study, optimization of nutritional parameters influencing melanin production by Mucuna monosperma callus cultures was attempted using the response surface methodology (RSM). Standardization of four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.978gL(-1), pH 5.85, SDS 34.55mgL(-1)and copper sulphate 21.14mgL(-1) tyrosine, which resulted in highest melanin yield of 0.887gL(-1). The optimization of medium using RSM resulted in a 3.06-fold increase in the yield of melanin. The ANOVA analysis showed a significant R(2)-value (0.9995), model F-value (1917.72) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for the continuous production of melanin. Uninterrupted flow column exhibited maximum melanin production rate of 250mgL(-1)h(-1) which is the highest value ever reported using plant as a biotransformation source. Melanin production was confirmed by spectrophotometric and chemical analysis. Thus, this study demonstrates the production of melanin by M. monosperma callus, using a laboratory scale column reactor.

  17. Optimization of flask culture medium and conditions for hyaluronic acid production by a streptococcus equisimilis mutant nc2168

    Directory of Open Access Journals (Sweden)

    Yong-Hao Chen

    2012-12-01

    Full Text Available A mutant designated NC2168, which was selected from wild-type Streptococcus equisimilis CVCC55116by ultraviolet ray combined with60Co-γ ray treatment and does not produce streptolysin, was employed to produce hyaluronic acid (HA. In order to increase the output of HA in a flask, the culture medium and conditions for NC2168 were optimized in this study. The influence of culture medium ingredients including carbon sources, nitrogen sources and metal ions on HA production was evaluated using factional factorial design. The mathematical model, which represented the effect of each medium component and their interaction on the yield of HA, was established by the quadratic rotary combination design and response surface method. The model estimated that, a maximal yield of HA could be obtained when the concentrations of yeast extract, peptone, glucose, and MgSO4 were set at 3 g/100 mL, 2 g/100 mL, 0.5 g/100 mL and 0.15 g/100 mL, respectively. Compared with the values obtained by other runs in the experimental design, the optimized medium resulted in a remarkable increase in the output of HA and the maximum of the predicted HA production was 174.76 mg/L. The model developed was accurate and reliable for predicting the production of HA by NC2168.Cultivation conditions were optimized by an orthogonal experimental design and the optimal conditions were as follows: temperature 33ºC, pH 7.8, agitation speed 200 rpm, medium volume 20 mL.

  18. Biological upgrading of coal liquids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    A large number of bacterial enrichments have been developed for their ability to utilize nitrogen and sulfur in coal liquids and the model compound naphtha. These bacteria include the original aerobic bacteria isolated from natural sources which utilize heteroatom compounds in the presence of rich media, aerobic nitrogen-utilizing bacteria and denitrifying bacteria. The most promising isolates include Mix M, a mixture of aerobic bacteria; ER15, a pyridine-utilizing isolate; ERI6, an aniline-utilizing isolate and a sewage sludge isolate. Culture optimization experiments have led to these bacteria being able to remove up to 40 percent of the sulfur and nitrogen in naphtha and coal liquids in batch culture. Continuous culture experiments showed that the coal liquid is too toxic to the bacteria to be fed without dilution or extraction. Thus either semi-batch operation must be employed with continuous gas sparging into a batch of liquid, or acid extracted coal liquid must be employed in continuous reactor studies with continuous liquid flow. Isolate EN-1, a chemical waste isolate, removed 27 percent of the sulfur and 19 percent of the nitrogen in fed batch experiments. Isolate ERI5 removed 28 percent of the nitrogen in coal liquid in 10 days in fed batch culture. The sewage sludge isolate removed 22.5 percent of the sulfur and 6.5 percent of the nitrogen from extracted coal liquid in continuous culture, and Mix M removed 17.5 percent of the nitrogen from medium containing extracted coal liquid. An economic evaluation has been prepared for the removal of nitrogen heteroatom compounds from Wilsonville coal liquid using acid extraction followed by fermentation. Similar technology can be developed for sulfur removal. The evaluation indicates that the nitrogen heteroatom compounds can be removed for $0.09/lb of coal liquid treated.

  19. Optimized determination of trace jet fuel volatile organic compounds in human blood using in-field liquid-liquid extraction with subsequent laboratory gas chromatographic-mass spectrometric analysis and on-column large-volume injection.

    Science.gov (United States)

    Liu, S; Pleil, J D

    2001-03-05

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing techniques, and a new on-column large-volume injection method for GC-MS analysis. With the optimized methods, the extraction efficiency was improved by 4.3 to 20.1 times and the detection sensitivity increased up to 660 times over the standard method. Typical detection limits in the parts-per-trillion (ppt) level range were achieved for all monitored JP-8 constituents; this is sufficient for assessing human fuels exposures at trace environmental levels as well as occupational exposure levels. The sample extractions are performed in the field and only solvent extracts need to be shipped to the laboratory. The method is implemented with standard biological laboratory equipment and a modest bench-top GC-MS system.

  20. Culture of primary ciliary dyskinesia epithelial cells at air-liquid interface can alter ciliary phenotype but remains a robust and informative diagnostic aid.

    Directory of Open Access Journals (Sweden)

    Robert A Hirst

    Full Text Available BACKGROUND: The diagnosis of primary ciliary dyskinesia (PCD requires the analysis of ciliary function and ultrastructure. Diagnosis can be complicated by secondary effects on cilia such as damage during sampling, local inflammation or recent infection. To differentiate primary from secondary abnormalities, re-analysis of cilia following culture and re-differentiation of epithelial cells at an air-liquid interface (ALI aids the diagnosis of PCD. However changes in ciliary beat pattern of cilia following epithelial cell culture has previously been described, which has brought the robustness of this method into question. This is the first systematic study to evaluate ALI culture as an aid to diagnosis of PCD in the light of these concerns. METHODS: We retrospectively studied changes associated with ALI-culture in 158 subjects referred for diagnostic testing at two PCD centres. Ciliated nasal epithelium (PCD n = 54; non-PCD n  111 was analysed by high-speed digital video microscopy and transmission electron microscopy before and after culture. RESULTS: Ciliary function was abnormal before and after culture in all subjects with PCD; 21 PCD subjects had a combination of static and uncoordinated twitching cilia, which became completely static following culture, a further 9 demonstrated a decreased ciliary beat frequency after culture. In subjects without PCD, secondary ciliary dyskinesia was reduced. CONCLUSIONS: The change to ciliary phenotype in PCD samples following cell culture does not affect the diagnosis, and in certain cases can assist the ability to identify PCD cilia.

  1. Efficient, validated method for detection of mycobacterial growth in liquid culture media by use of bead beating, magnetic-particle-based nucleic acid isolation, and quantitative PCR.

    Science.gov (United States)

    Plain, Karren M; Waldron, Anna M; Begg, Douglas J; de Silva, Kumudika; Purdie, Auriol C; Whittington, Richard J

    2015-04-01

    Pathogenic mycobacteria are difficult to culture, requiring specialized media and a long incubation time, and have complex and exceedingly robust cell walls. Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease, a chronic wasting disease of ruminants, is a typical example. Culture of MAP from the feces and intestinal tissues is a commonly used test for confirmation of infection. Liquid medium offers greater sensitivity than solid medium for detection of MAP; however, support for the BD Bactec 460 system commonly used for this purpose has been discontinued. We previously developed a new liquid culture medium, M7H9C, to replace it, with confirmation of growth reliant on PCR. Here, we report an efficient DNA isolation and quantitative PCR methodology for the specific detection and confirmation of MAP growth in liquid culture media containing egg yolk. The analytical sensitivity was at least 10(4)-fold higher than a commonly used method involving ethanol precipitation of DNA and conventional PCR; this may be partly due to the addition of a bead-beating step to manually disrupt the cell wall of the mycobacteria. The limit of detection, determined using pure cultures of two different MAP strains, was 100 to 1,000 MAP organisms/ml. The diagnostic accuracy was confirmed using a panel of cattle fecal (n=54) and sheep fecal and tissue (n=90) culture samples. This technique is directly relevant for diagnostic laboratories that perform MAP cultures but may also be applicable to the detection of other species, including M. avium and M. tuberculosis.

  2. Multiobjective optimization of the operation of a liquid-solid circulating fluidized bed ion-exchange system for continuous protein recovery.

    Science.gov (United States)

    Mazumder, Jahirul; Zhu, Jingxu; Bassi, Amarjeet S; Ray, Ajay K

    2009-08-01

    Like most real-life processes, the operation of liquid-solid circulating fluidized bed (LSCFB) system for continuous protein recovery is associated with several objectives such as maximization of production rate and recovery of protein, and minimization of amount solid ion-exchange resin requirement, all of which need to be optimized simultaneously. In this article, multiobjective optimization of a LSCFB system for continuous protein recovery was carried out using an experimentally validated mathematical model to find the scope for further improvements in its operation. Elitist non-dominated sorting genetic algorithm with its jumping gene adaptation was used to solve a number of bi- and tri-objective function optimization problems. The optimization resulted in Pareto-optimal solution, which provides a broad range of non-dominated solutions due to conflicting behavior of the operating parameters on the system performance indicators. Significant improvements were achieved, for example, the production rate at optimal operation increased by 33%, using 11% less solid compared to reported experimental results for the same recovery level. The effects of operating variables on the optimal solutions are discussed in detail. The multiobjective optimization study reported here can be easily extended for the improvement of LSCFB system for other applications.

  3. The effect of plant growth regulators on optimization of tissue culture ...

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... tissue culture system in Malaysian upland rice. E. Shahsavari1*, A. A. .... The experiments were arranged in a completely randomized design with four replications. ..... Plant Cell Tissue Organ Cult. 37: 217-242. Ge XJ, Chu ZH, ...

  4. Optimizing carbon dioxide and light levels during in vitro culture of Theobroma cacao

    Energy Technology Data Exchange (ETDEWEB)

    Figueira, A.; Janick, J. (Purdue Univ., West Lafayette, IN (United States). Dept. of Horticulture)

    1994-07-01

    In vitro culture of axillary cotyledonary shoots of Theobroma cacao L. (cacao) under increasing CO[sub 2] concentration from ambient to 24,000 ppm (culture tube levels) significantly increased total shoot elongation, number of leaves, leaf area per explant, and shoot dry and fresh weight. Although light was necessary for the CO[sub 2] response, the effect of various photon fluxes was not significant for the measured growth parameters. Net photosynthesis estimated on the basis of CO[sub 2] depletion in culture tubes increased 3.5 times from 463 to 2639 ppm CO[sub 2], and increased 1.5 times from 2,639 to 14,849 ppm CO[sub 2], but declined from 14,849 to 24,015 ppm CO[sub 2]. Ethylene concentration in culture vessels increased under enriched CO[sub 2] conditions. Depletion of nutrients (fructose, K, Ca, Mg, and P) from the medium was increased under enriched CO[sub 2] conditions.

  5. Addition of formic acid or starter cultures to liquid feed. Effect on pH, microflora composition, organic acid concentration and ammonia concentration.

    Science.gov (United States)

    Canibe, N; Miquel, N; Miettinen, H; Jensen, B B

    2001-01-01

    Some of the charateristics of good quality fermented liquid feed (FLF) are low pH, high numbers of lactic acid bacteria, and low numbers of enterobacteria. In order to test strategies to avoid a proliferation of enterobacteria during the initial phase of FLF elaboration, two in vitro studies were carried out. Addition of various doses of formic acid or two different starter cultures were tested. Adding 0.1% formic acid or L. plantarum VTT E-78076 to the liquid feed seemed to be addecuate ways of inhibiting the growth of enterobacteria, without depleting the growth of lactic acid bacteria.

  6. Evidence for the involvement of nematocidal toxins of Purpureocillium lilacinum 6029 cultured on Karanja deoiled cake liquid medium.

    Science.gov (United States)

    Sharma, Abhishek; Sharma, Satyawati; Mittal, Aditya; Naik, S N

    2016-05-01

    In present study, in vitro nematocidal bioassays, FT-IR and HPLC analysis were employed to demonstrate the involvement of toxins of Purpureocillium lilacinum in killing root-knot nematodes (Meloidogyne incognita). During growth study, maximum mycelial biomass (10.52 g/l) in de-oiled Karanja cake medium was achieved on 8th day while complete mortality of nematodes was obtained by 6th day filtrate (FKSM). Maximum production of crude nematocidal toxin was recorded on 7th day suggesting that the toxin production was paralleled with growth of the fungus. The median lethal concentration (LC50) determined for the crude toxin from 6th day to 10th day ranged from 89.41 to 43.21 ppm. The median lethal time (LT50) for the crude toxin of FKSM was found to be 1.46 h. This is the first report of implementing a comparative infra-red spectroscopy coupled with HPLC analysis to predict the presence of nematocidal toxin in the fungal filtrate cultured on Karanja deoiled cake liquid medium.

  7. Hydrogel design of experiments methodology to optimize hydrogel for iPSC-NPC culture.

    Science.gov (United States)

    Lam, Jonathan; Carmichael, S Thomas; Lowry, William E; Segura, Tatiana

    2015-03-11

    Bioactive signals can be incorporated in hydrogels to direct encapsulated cell behavior. Design of experiments methodology methodically varies the signals systematically to determine the individual and combinatorial effects of each factor on cell activity. Using this approach enables the optimization of three ligands concentrations (RGD, YIGSR, IKVAV) for the survival and differentiation of neural progenitor cells.

  8. Statistical analysis of optimal culture conditions for Gluconacetobacter hansenii cellulose production.

    Science.gov (United States)

    Hutchens, S A; León, R V; O'neill, H M; Evans, B R

    2007-02-01

    The purpose of this study was to analyse the effects of different culture parameters on Gluconacetobacter hansenii (ATCC 10821) to determine which conditions provided optimum cellulose growth. Five culture factors were investigated: carbon source, addition of ethanol, inoculation ratio, pH and temperature. jmp Software (SAS, Cary, NC, USA) was used to design this experiment using a fractional factorial design. After 22 days of static culture, the cellulose produced by the bacteria was harvested, purified and dried to compare the cellulose yields. The results were analysed by fitting the data to a first-order model with two-factor interactions. The study confirmed that carbon source, addition of ethanol, and temperature were significant factors in the production of cellulose of this G. hansenii strain. While pH alone does not significantly affect average cellulose production, cellulose yields are affected by pH interaction with the carbon source. Culturing the bacteria on glucose at pH 6.5 produces more cellulose than at pH 5.5, while using mannitol at pH 5.5 produces more cellulose than at pH 6.5. The bacteria produced the most cellulose when cultured on mannitol, at pH 5.5, without ethanol, at 20 degrees C. Inoculation ratio was not found to be a significant factor or involved in any significant two-factor interaction. These findings give insight into the conditions necessary to maximize cellulose production from this G. hansenii strain. In addition, this work demonstrates how the fractional factorial design can be used to test a large number of factors using an abbreviated set of experiments. Fitting a statistical model determined the significant factors as well as the significant two-factor interactions.

  9. Cultural determinants of optimal breastfeeding practices among indigenous Mam-Mayan women in the Western Highlands of Guatemala.

    Science.gov (United States)

    Wren, Hilary M; Solomons, Noel W; Chomat, Anne Marie; Scott, Marilyn E; Koski, Kristine G

    2015-02-01

    Among indigenous Mam-Mayan women, breastfeeding practices may be intertwined with cultural influences during the early postpartum period. Our study explored whether beliefs regarding transmission of emotions through breast milk, the feeding of agüitas or temascal (traditional sauna) use were associated with achievement of the World Health Organization infant feeding recommendations and if these cultural practices served as moderators of the relationship between optimal breastfeeding practices and infant anthropometry. We recruited 190 mother-infant dyads at infant age breastfeeding and cultural practices were collected via questionnaire. Infant length, weight, and head circumference were measured and z scores were calculated. Multiple linear and logistic regression analyses were used to examine determinants of initiation of breastfeeding within 1 hour, breastfeeding frequency, breastfeeding exclusivity, and infant weight-for-age z score (WAZ). Mothers who delivered at the traditional midwife's house (odds ratio [OR] = 2.5) and those who did not believe in the transmission of susto (fright) through breast milk (OR = 2.4) were more likely to initiate breastfeeding within 1 hour postpartum. Higher breastfeeding frequency was observed among mothers who spent more time in the temascal. Initiating early breastfeeding within 1 hour postpartum was the sole infant feeding practice positively associated with exclusive breastfeeding and WAZ. Our investigation in the Western Highlands of Guatemala has highlighted the link between cultural practices and beliefs during lactation, breastfeeding practices and infant growth. Public health practitioners need to understand how local cultural practices influence early initiation of breastfeeding to promote adequate infant weight. © The Author(s) 2014.

  10. Application of response surface methodology to optimize pressurized liquid extraction of antioxidant compounds from sage (Salvia officinalis L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.).

    Science.gov (United States)

    Hossain, M B; Brunton, N P; Martin-Diana, A B; Barry-Ryan, C

    2010-12-01

    The present study optimized pressurized liquid extraction (PLE) conditions using Dionex ASE® 200, USA to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)] and total polyphenol content (TP) of the extracts from three spices of Lamiaceae family (sage, basil and thyme). Optimal conditions with regard to extraction temperature (66-129 °C) and solvent concentration (32-88% methanol) were identified using response surface methodology (RSM). For all three spices, results showed that 129 °C was the optimum temperature with regard to antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of sage and basil extracts were 58% and 60% respectively. Thyme showed a different trend with regard to methanol concentration and was optimally extracted at 33%. Antioxidant activity yields of the optimal PLE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for both total phenol (TP) and FRAP values in all the spices with high regression coefficients (R(2)) ranging from 0.651 to 0.999.

  11. A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism

    Science.gov (United States)

    Yu, Lei; Tang, Qing-wen; Zhang, Yu-jia; Chen, Rong-ping; Liu, Xin; Qiao, Wei-chuan; Li, Wen-wei; Ruan, Hong-hua; Song, Xin

    2016-01-01

    In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe3+, the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from −39.0 mV to 43.4 mV in the presence of Fe3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe3+ and Al3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching. PMID:27713559

  12. Selection and optimization of transfection enhancer additives for increased virus-like particle production in HEK293 suspension cell cultures.

    Science.gov (United States)

    Cervera, Laura; Fuenmayor, Javier; González-Domínguez, Irene; Gutiérrez-Granados, Sonia; Segura, Maria Mercedes; Gòdia, Francesc

    2015-12-01

    The manufacturing of biopharmaceuticals in mammalian cells typically relies on the use of stable producer cell lines. However, in recent years, transient gene expression has emerged as a suitable technology for rapid production of biopharmaceuticals. Transient gene expression is particularly well suited for early developmental phases, where several potential therapeutic targets need to be produced and tested in vivo. As a relatively new bioprocessing modality, a number of opportunities exist for improving cell culture productivity upon transient transfection. For instance, several compounds have shown positive effects on transient gene expression. These transfection enhancers either facilitate entry of PEI/DNA transfection complexes into the cell or nucleus or increase levels of gene expression. In this work, the potential of combining transfection enhancers to increase Gag-based virus-like particle production levels upon transfection of suspension-growing HEK 293 cells is evaluated. Using Plackett-Burman design of experiments, it is first tested the effect of eight transfection enhancers: trichostatin A, valproic acid, sodium butyrate, dimethyl sulfoxide (DMSO), lithium acetate, caffeine, hydroxyurea, and nocodazole. An optimal combination of compounds exhibiting the highest effect on gene expression levels was subsequently identified using a surface response experimental design. The optimal consisted on the addition of 20 mM lithium acetate, 3.36 mM valproic acid, and 5.04 mM caffeine which increased VLP production levels 3.8-fold, while maintaining cell culture viability at 94%.

  13. Optimizing Culture System of Ri T-DNA Transformed Roots for Citrus grandis cv. Changshou Shatian You

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-hong; SUN Zhong-hai; TONG Rui-jian

    2006-01-01

    Genetic transformation experiments of the different explants from Citrus grandis cv. Changshou Shatian You infected with Agrobacterium rhizogenes were carried out in darkness or in light. The optimizing culture system of Ri T-DNA transformed roots for C. grandis cv. Changshou Shatian You was constructed as follows: After the ventral wounded striations on the single activation cotyledon were inoculated by A. rhizogenes A4 (logarithmic period), they were cocultured at (25 ± 2)℃ in darkness for 25-30 days; some transformed roots were generated from wounded striations of most cotyledons. The genetically transformed ratio is (83 ± 11)%. Axenic Ri T-DNA transformed roots (hairy roots) were harvested after five subcultures. Explants were activated on MT medium. The MS medium was used for subculture of transformed roots. Mass Ri T-DNA transformed roots in which the hormone was produced independently were harvested from this optimizing culture system. White, fresh Ri T-DNA transformed roots were (1.14 ± 0.07) cm long, (0.73 ± 0.04) mm wide, and the growth direction of transformed roots was negative geotropism.

  14. Optimization of Cultural Conditions for Production of Antibacterial Metabolites from Streptomyces coelicoflavus BC 01

    Directory of Open Access Journals (Sweden)

    Kothagorla Venkata RAGHAVA RAO

    2015-06-01

    Full Text Available The aim of the present study was to optimize various cultural conditions for the production of antibacterial metabolites by Streptomyces coelicoflavus BC 01 isolated from mangrove soil, Visakhapatnam, Andhra Pradesh, India. The effect of various factors such as carbon and nitrogen sources, different concentrations of NaCl and K2HPO4, different temperature, pH, incubation time and agitation on antibacterial metabolites production were studied. The production of antibacterial metabolites by the isolate Streptomyces coelicoflavus BC 01 was greatly influenced by the cultural conditions. Glucose (1.2% and soya bean meal (1% seemed to be the best carbon and nitrogen source respectively, followed by NaCl (1% and K2HPO4 (0.25%. Maximum production of antibacterial metabolites was observed at a temperature of 30 °C, with pH 7.2, at 160 rpm for 96 hrs. These optimized parameters can be further useful to design a fermentation medium to achieve maximum yield of antibacterial metabolites from Streptomyces coelicoflavus BC 01.

  15. Robust optimization for nonlinear time-delay dynamical system of dha regulon with cost sensitivity constraint in batch culture

    Science.gov (United States)

    Yuan, Jinlong; Zhang, Xu; Liu, Chongyang; Chang, Liang; Xie, Jun; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

    2016-09-01

    Time-delay dynamical systems, which depend on both the current state of the system and the state at delayed times, have been an active area of research in many real-world applications. In this paper, we consider a nonlinear time-delay dynamical system of dha-regulonwith unknown time-delays in batch culture of glycerol bioconversion to 1,3-propanediol induced by Klebsiella pneumonia. Some important properties and strong positive invariance are discussed. Because of the difficulty in accurately measuring the concentrations of intracellular substances and the absence of equilibrium points for the time-delay system, a quantitative biological robustness for the concentrations of intracellular substances is defined by penalizing a weighted sum of the expectation and variance of the relative deviation between system outputs before and after the time-delays are perturbed. Our goal is to determine optimal values of the time-delays. To this end, we formulate an optimization problem in which the time delays are decision variables and the cost function is to minimize the biological robustness. This optimization problem is subject to the time-delay system, parameter constraints, continuous state inequality constraints for ensuring that the concentrations of extracellular and intracellular substances lie within specified limits, a quality constraint to reflect operational requirements and a cost sensitivity constraint for ensuring that an acceptable level of the system performance is achieved. It is approximated as a sequence of nonlinear programming sub-problems through the application of constraint transcription and local smoothing approximation techniques. Due to the highly complex nature of this optimization problem, the computational cost is high. Thus, a parallel algorithm is proposed to solve these nonlinear programming sub-problems based on the filled function method. Finally, it is observed that the obtained optimal estimates for the time-delays are highly satisfactory

  16. Characterization of eight terpenoids from tissue cultures of the Chinese herbal plant, Tripterygium wilfordii, by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Su, Ping; Cheng, Qiqing; Wang, Xiujuan; Cheng, Xiaoqing; Zhang, Meng; Tong, Yuru; Li, Fei; Gao, Wei; Huang, Luqi

    2014-09-01

    In this study, a reliable method for analysis and identification of eight terpenoids in tissue cultures of Tripterygium wilfordii has been established using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS). Our study indicated that sterile seedlings, callus cultures and cell-suspension cultures can rapidly increase the amount of biological materials. HPLC-ESI-MS was used to identify terpenoids from the extracts of these tissue cultures. Triptolide, triptophenolide, celastrol and wilforlide A were unambiguously determined by comparing the retention times, UV spectral data, and mass fragmentation behaviors with those of the reference compounds. Another four compounds were tentatively identified as triptonoterpenol, triptonoterpene, 22β-hydroxy-3-oxoolean-12-en-29-oic acid and wilforlide B, based on their UV and mass spectrometry spectra. The quantitative analysis showed that all three materials contain triptolide, triptophenolide, celastrol, wilforlide A, and the contents of the four compounds in the cell-suspension cultures were 53.1, 240, 129 and 964 µg/g, respectively, which were at least 2.0-fold higher than these in the sterile seedlings and callus cultures. Considering the known pharmacological activity of triptolide and celastrol, we recommend the cell-suspension cultures as biological materials for future studies, such as clinical and toxicological studies. The developed method was validated by the evaluation of its precision, linearity, detection limits and recovery, and it was successfully used to identify and quantify the terpenoids in the tissue cultures.

  17. Optimization of dynamic headspace extraction system for measurement of halogenated volatile organic compounds in liquid or viscous samples

    Science.gov (United States)

    Taniai, G.; Oda, H.; Kurihara, M.; Hashimoto, S.

    2010-12-01

    Halogenated volatile organic compounds (HVOCs) produced in the marine environment are thought to play a key role in atmospheric reactions, particularly those involved in the global radiation budget and the depression of tropospheric and stratospheric ozone. To evaluate HVOCs concentrations in the various natural samples, we developed an automated dynamic headspace extraction method for the determination of 15 HVOCs, such as chloromethane, bromomethane, bromoethane, iodomethane, iodoethane, bromochloromethane, 1-iodopropane, 2-iodopropane, dibromomethane, bromodichloromethane, chloroiodomethane, chlorodibromomethane, bromoiodomethane, tribromomethane, and diiodomethane. Dynamic headspace system (GERSTEL DHS) was used to purge the gas phase above samples and to trap HVOCs on the adsorbent column from the purge gas. We measured the HVOCs concentrations in the adsorbent column with gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). In dynamic headspace system, an glass tube containing Tenax TA or Tenax GR was used as adsorbent column for the collection of 15 HVOCs. The parameters for purge and trap extraction, such as purge flow rate (ml/min), purge volume (ml), incubation time (min), and agitator speed (rpm), were optimized. The detection limits of HVOCs in water samples were 1270 pM (chloromethane), 103 pM (bromomethane), 42.1 pM (iodomethane), and 1.4 to 10.2 pM (other HVOCs). The repeatability (relative standard deviation) for 15 HVOCs were < 9 % except chloromethane (16.2 %) and bromomethane (11.0 %). On the basis of the measurements for various samples, we concluded that this analytical method is useful for the determination of wide range of HVOCs with boiling points between - 24°C (chloromethane) and 181°C (diiodomethane) for the liquid or viscous samples.

  18. Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 in liquid broth medium and during processing of fermented sausage using autochthonous starter cultures.

    Science.gov (United States)

    Pragalaki, T; Bloukas, J G; Kotzekidou, P

    2013-11-01

    The antimicrobial effect of two autochthonous starter cultures of Lactobacillus sakei was evaluated in vitro (in liquid broth medium) and in situ assays. The inactivation of foodborne pathogens Listeria monocytogenes (serotype 4ab No 10) and Escherichia coli O157:H7 ATCC 43888 was investigated during the production of fermented sausage according to a typical Greek recipe using L. sakei strains as starter cultures. The inactivation kinetics were modeled using GInaFiT, a freeware tool to assess microbial survival curves. By the end of the ripening period, the inhibition of L. monocytogenes was significant in treatments with L. sakei 8416 and L. sakei 4413 compared to the control treatment. A 2.2-log reduction of the population of E. coli O157:H7 resulted from the autochthonous starter culture L. sakei 4413 during sausage processing. The use of the autochthonous starter cultures constitutes an additional improvement to the microbial safety by reducing foodborne pathogens.

  19. Optimization of Culture Conditions and Medium Composition for the Marine Algicidal Bacterium Alteromonas sp.DH46 by Uniform Design

    Institute of Scientific and Technical Information of China (English)

    LIN Jing; ZHENG Wei; TIAN Yun; WANG Guizhong; ZHENG Tianling

    2013-01-01

    Harmful algal blooms (HABs) have led to extensive ecological and environmental issues and huge economic losses.Various HAB control techniques have been developed,and biological methods have been paid more attention.Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner,and kill or damage the algal cells.A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp.The culture conditions were optimized using a single-factor test method.Factors including carbon source,nitrogen source,temperature,initial pH value,rotational speed and salinity were studied.The results showed that the cultivation of the bacteria at 28℃ and 180r min-1 with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46.The optimal medium composition for strain DH46 was determined by means of uniform design experimentation,and the most important components influencing the cell density were tryptone,yeast extract,soluble starch,NaNO3 and MgSO4.When the following culture medium was used (tryptone 14.0g,yeast extract 1.63g,soluble starch 5.0g,NaNO3 1.6g,MgSO4 2.3 g in 1L),the largest bacterial dry weight (7.36gL-1) was obtained,which was an enhancement of 107% compared to the initial medium; and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.

  20. Optimization of fermentation parameters to study the behavior of selected lactic cultures on soy solid state fermentation.

    Science.gov (United States)

    Rodríguez de Olmos, A; Bru, E; Garro, M S

    2015-03-02

    The use of solid fermentation substrate (SSF) has been appreciated by the demand for natural and healthy products. Lactic acid bacteria and bifidobacteria play a leading role in the production of novel functional foods and their behavior is practically unknown in these systems. Soy is an excellent substrate for the production of functional foods for their low cost and nutritional value. The aim of this work was to optimize different parameters involved in solid state fermentation (SSF) using selected lactic cultures to improve soybean substrate as a possible strategy for the elaboration of new soy food with enhanced functional and nutritional properties. Soy flour and selected lactic cultures were used under different conditions to optimize the soy SSF. The measured responses were bacterial growth, free amino acids and β-glucosidase activity, which were analyzed by applying response surface methodology. Based on the proposed statistical model, different fermentation conditions were raised by varying the moisture content (50-80%) of the soy substrate and temperature of incubation (31-43°C). The effect of inoculum amount was also investigated. These studies demonstrated the ability of selected strains (Lactobacillus paracasei subsp. paracasei and Bifidobacterium longum) to grow with strain-dependent behavior on the SSF system. β-Glucosidase activity was evident in both strains and L. paracasei subsp. paracasei was able to increase the free amino acids at the end of fermentation under assayed conditions. The used statistical model has allowed the optimization of fermentation parameters on soy SSF by selected lactic strains. Besides, the possibility to work with lower initial bacterial amounts to obtain results with significant technological impact was demonstrated.

  1. Optimization of culture conditions and medium composition for the marine algicidal bacterium Alteromonas sp. DH46 by uniform design

    Science.gov (United States)

    Lin, Jing; Zheng, Wei; Tian, Yun; Wang, Guizhong; Zheng, Tianling

    2013-09-01

    Harmful algal blooms (HABs) have led to extensive ecological and environmental issues and huge economic losses. Various HAB control techniques have been developed, and biological methods have been paid more attention. Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner, and kill or damage the algal cells. A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp. The culture conditions were optimized using a single-factor test method. Factors including carbon source, nitrogen source, temperature, initial pH value, rotational speed and salinity were studied. The results showed that the cultivation of the bacteria at 28°C and 180 r min-1 with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46. The optimal medium composition for strain DH46 was determined by means of uniform design experimentation, and the most important components influencing the cell density were tryptone, yeast extract, soluble starch, NaNO3 and MgSO4. When the following culture medium was used (tryptone 14.0g, yeast extract 1.63g, soluble starch 5.0 g, NaNO3 1.6 g, MgSO4 2.3 g in 1L), the largest bacterial dry weight (7.36 g L-1) was obtained, which was an enhancement of 107% compared to the initial medium; and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.

  2. Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats.

    Science.gov (United States)

    Goyal, Ritu; Guvendiren, Murat; Freeman, Onyi; Mao, Yong; Kohn, Joachim

    2017-01-11

    The design of composite tissue scaffolds containing an extracellular matrix (ECM) and synthetic polymer fibers is a new approach to create bioactive scaffolds that can enhance cell function. Currently, studies investigating the effects of ECM-deposition and decellularization on polymer degradation are still lacking, as are data on optimizing the stability of the ECM-containing composite scaffolds during prolonged cell culture. In this study, we develop fibrous scaffolds using three polymer compositions, representing slow (E0000), medium (E0500), and fast (E1000) degrading materials, to investigate the stability, degradation, and mechanics of the scaffolds during ECM deposition and decellularization, and during the complete cellularization-decell-recell cycle. We report data on percent molecular weight (% Mw) retention of polymeric fiber mats, changes in scaffold stiffness, ECM deposition, and the presence of fibronectin after decellularization. We concluded that the fast degrading E1000 (Mw retention ≤ 50% after 28 days) was not sufficiently stable to allow scaffold handling after 28 days in culture, while the slow degradation of E0000 (Mw retention ≥ 80% in 28 days) did not allow deposited ECM to replace the polymer support. The scaffolds made from medium degrading E0500 (Mw retention about 60% at 28 days) allowed the gradual replacement of the polymer network with cell-derived ECM while maintaining the polymer network support. Thus, polymers with an intermediate rate of degradation, maintaining good scaffold handling properties after 28 days in culture, seem best suited for creating ECM-polymer composite scaffolds.

  3. Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats

    Directory of Open Access Journals (Sweden)

    Ritu Goyal

    2017-01-01

    Full Text Available The design of composite tissue scaffolds containing an extracellular matrix (ECM and synthetic polymer fibers is a new approach to create bioactive scaffolds that can enhance cell function. Currently, studies investigating the effects of ECM-deposition and decellularization on polymer degradation are still lacking, as are data on optimizing the stability of the ECM-containing composite scaffolds during prolonged cell culture. In this study, we develop fibrous scaffolds using three polymer compositions, representing slow (E0000, medium (E0500, and fast (E1000 degrading materials, to investigate the stability, degradation, and mechanics of the scaffolds during ECM deposition and decellularization, and during the complete cellularization-decell-recell cycle. We report data on percent molecular weight (% Mw retention of polymeric fiber mats, changes in scaffold stiffness, ECM deposition, and the presence of fibronectin after decellularization. We concluded that the fast degrading E1000 (Mw retention ≤ 50% after 28 days was not sufficiently stable to allow scaffold handling after 28 days in culture, while the slow degradation of E0000 (Mw retention ≥ 80% in 28 days did not allow deposited ECM to replace the polymer support. The scaffolds made from medium degrading E0500 (Mw retention about 60% at 28 days allowed the gradual replacement of the polymer network with cell-derived ECM while maintaining the polymer network support. Thus, polymers with an intermediate rate of degradation, maintaining good scaffold handling properties after 28 days in culture, seem best suited for creating ECM-polymer composite scaffolds.

  4. Optimization of Femtosecond Laser Polymerized Structural Niches to Control Mesenchymal Stromal Cell Fate in Culture

    Directory of Open Access Journals (Sweden)

    Manuela T. Raimondi

    2014-06-01

    Full Text Available We applied two-photon polymerization to fabricate 3D synthetic niches arranged in complex patterns to study the effect of mechano-topological parameters on morphology, renewal and differentiation of rat mesenchymal stromal cells. Niches were formed in a photoresist with low auto-fluorescence, which enabled the clear visualization of the fluorescence emission of the markers used for biological diagnostics within the internal niche structure. The niches were structurally stable in culture up to three weeks. At three weeks of expansion in the niches, cell density increased by almost 10-fold and was 67% greater than in monolayer culture. Evidence of lineage commitment was observed in monolayer culture surrounding the structural niches, and within cell aggregates, but not inside the niches. Thus, structural niches were able not only to direct stem cell homing and colony formation, but also to guide aggregate formation, providing increased surface-to-volume ratios and space for stem cells to adhere and renew, respectively.

  5. Cultured Neural Networks: Optimization of Patterned Network Adhesiveness and Characterization of their Neural Activity

    Directory of Open Access Journals (Sweden)

    W. L. C. Rutten

    2006-01-01

    Full Text Available One type of future, improved neural interface is the “cultured probe”. It is a hybrid type of neural information transducer or prosthesis, for stimulation and/or recording of neural activity. It would consist of a microelectrode array (MEA on a planar substrate, each electrode being covered and surrounded by a local circularly confined network (“island” of cultured neurons. The main purpose of the local networks is that they act as biofriendly intermediates for collateral sprouts from the in vivo system, thus allowing for an effective and selective neuron–electrode interface. As a secondary purpose, one may envisage future information processing applications of these intermediary networks. In this paper, first, progress is shown on how substrates can be chemically modified to confine developing networks, cultured from dissociated rat cortex cells, to “islands” surrounding an electrode site. Additional coating of neurophobic, polyimide-coated substrate by triblock-copolymer coating enhances neurophilic-neurophobic adhesion contrast. Secondly, results are given on neuronal activity in patterned, unconnected and connected, circular “island” networks. For connected islands, the larger the island diameter (50, 100 or 150 μm, the more spontaneous activity is seen. Also, activity may show a very high degree of synchronization between two islands. For unconnected islands, activity may start at 22 days in vitro (DIV, which is two weeks later than in unpatterned networks.

  6. Optimization for Production of Intracellular Polysaccharide from Cordyceps ophioglossoides L2 in Submerged Culture and Its Antioxidant Activities in vitro

    Institute of Scientific and Technical Information of China (English)

    许勤勤; 刘振华; 孙一晟; 丁忠杰; 吕龙贤; 李永泉

    2012-01-01

    Cordyceps ophioglossoides is a valuable traditional medicinal material.We have found that intracellular polysaccharide(IPS) is the major biologically active ingredient in Cordyceps ophioglossoides.This study is the first time to optimize the yield of IPS from Cordyceps ophioglossoides.The optimal medium for IPS production consists of glucose 54.50 g·L^-1,yeast powder 25.50 g·L^-1,NaH2PO4 0.4 g·L^-1 and K2HPO4 0.4 g·L^-1.The suggested culture conditions are 24 ℃,initial pH 4.5 with a rotary speed of 120 r·min^-1 for 168 h.The yield of IPS is 737.93 mg·L^-1,which is 50% higher than the yield under the conditions prior to optimization.The anti-oxidative activities of IPS in Cordyceps ophioglossoides L2 are also characterized using various in vitro assay.The anti-oxidative activity may explain the reason why IPS from Cordyceps ophioglossoides can be used to fight against neurodegenerative dis-eases and menopausal symptoms.

  7. Global Liquidity Trap

    OpenAIRE

    Fujiwara, Ippei; NAKAJIMA Tomoyuki; Sudo, Nao; Teranishi, Yuki

    2011-01-01

    In this paper we consider a two-country New Open Economy Macroeconomics model, and analyze the optimal monetary policy when countries cooperate in the face of a "global liquidity trap" -- i.e., a situation where the two countries are simultaneously caught in liquidity traps. The notable features of the optimal policy in the face of a global liquidity trap are history dependence and international dependence. The optimality of history dependent policy is confirmed as in local liquidity trap. A ...

  8. Optimization of two different dispersive liquid-liquid microextraction methods followed by gas chromatography-mass spectrometry determination for polycyclic aromatic hydrocarbons (PAHs) analysis in water.

    Science.gov (United States)

    Tseng, Wan-Chi; Chen, Pai-Shan; Huang, Shang-Da

    2014-03-01

    Novel sample preparation methods termed "up-and-down shaker-assisted dispersive liquid-liquid microextraction (UDSA-DLLME)" and "water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid-liquid microextraction (WLSEME)" coupled with gas chromatography-mass spectrometry (GC-MS) have been developed for the analysis of 11 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. For UDSA-DLLME, an up-and-down shaker-assisted emulsification was employed. Extraction was complete in 3min. Only 14 μL of 1-heptanol was required, without a dispersive solvent. Under the optimum conditions, the linear range was 0.08-100 µg L(-1), and the LODs were in the range 0.022-0.060 µg L(-1). The enrichment factors (EFs) ranged from 392 to 766. Relative recoveries were between 84% and 113% for river, lake, and field water. In WLSEME, 9 μL of 1-nonanol as extraction solvent and 240 μL of 1 mg L(-1) Triton X-100 as surfactant were mixed in a microsyringe to form a cloudy emulsified solution, which was then injected into the samples. Compared with other surfactant-assisted emulsion methods, WLSEME uses much less surfactant. The linear range was 0.08-100 µg L(-1), and the LODs were 0.022-0.13 µg L(-1). The EFs ranged from 388 to 649. The relative recoveries were 86-114% for all three water specimens.

  9. A novel method to optimize culture conditions for biomass and sporulation of the entomopathogenic fungus Beauveria Bassiana IBC1201

    Directory of Open Access Journals (Sweden)

    Li Gao

    2011-12-01

    Full Text Available Biomass yields and sporulation of Beauveria bassiana was concerned on culture conditions, environmental factors and cultivation method. We optimized the best culture conditions for biomass yields of B. bassiana IBC1201 with the novel "two-stage" cultivation method as well as orthogonal matrix method. Firstly, we cultured spore suspension on the basal medium (sucrose 19.00 g, soy peptone 4.06 g, K2HPO4 1.00 g, KCl 0.50 g, MgSO4 0.50 g, FeSO4 0.10 g and 17.00 g Bactor for the first stage culture of 4 days under room condition. Then, we transferred them to another defined medium (Cellobiose 9.52 g, urea 1.70 g, ZnSO4•7H2O 0.05 g/L, MnSO4•H2O 0.005 g/L, CaCl2 1.00 g/L, CuSO4•5H2O 0.05 g/L and 17.00 g Bactor for more 4 days cultivation with the environmental factors combination of water potential -1.2 MPa /pH 3 /12 h light cycle/ 23 ℃ for biomass yields, and with the environmental factors combination of water potential -0.8 MPa /pH 3 /24 h light cycle/ 23 ℃ for spore yields. These results provided important information for mass production (including biomass and spore yields of this great potential biocontrol fungus.

  10. A novel method to optimize culture conditions for biomass and sporulation of the entomopathogenic fungus Beauveria bassiana IBC1201.

    Science.gov (United States)

    Gao, Li

    2011-10-01

    Biomass yields and sporulation of Beauveria bassiana was concerned on culture conditions, environmental factors and cultivation method. We optimized the best culture conditions for biomass yields of B. bassiana IBC1201 with the novel "two-stage" cultivation method as well as orthogonal matrix method. Firstly, we cultured spore suspension on the basal medium (sucrose 19.00 g, soy peptone 4.06 g, K2HPO4 1.00 g, KCl 0.50 g, MgSO4 0.50 g, FeSO4 0.10 g and 17.00 g Bactor) for the first stage culture of 4 days under room condition. Then, we transferred them to another defined medium (Cellobiose 9.52 g, urea 1.70 g, ZnSO4•7H2O 0.05 g/L, MnSO4•H2O 0.005 g/L, CaCl2 1.00 g/L, CuSO4•5H2O 0.05 g/L and 17.00 g Bactor) for more 4 days cultivation with the environmental factors combination of water potential -1.2 MPa /pH 3 /12 h light cycle/23 ℃ for biomass yields, and with the environmental factors combination of water potential -0.8 MPa /pH 3 /24 h light cycle/23 ℃ for spore yields. These results provided important information for mass production (including biomass and spore yields) of this great potential biocontrol fungus.

  11. Hairy root culture optimization and resveratrol production from Vitis vinifera subsp. sylvesteris.

    Science.gov (United States)

    Hosseini, Sayed Mehdi; Bahramnejad, Bahman; Douleti Baneh, Hamed; Emamifar, Aryo; Goodwin, Paul H

    2017-04-01

    Resveratrol is a polyphenolic compound produced in very low levels in grapes. To achieve high yield of resveratrol in wild grape, three Agrobacterium rhizogenes strains, Ar318, ArA4 and LBA9402, were used to induce hairy roots following infection of internodes, nodes or petioles of in vitro grown Vitis vinifera subsp. sylvesteris accessions W2 and W16, and cultivar Rasha. The effects of inoculation time, age of explants, bacterial concentration and co-cultivation times were examined on the efficiency of the production of hairy roots. Strains Ar318, ArA4 and LBA9402 all induced hairy roots in the tested genotypes, but the efficiency of ArA4 strain was higher than the other strains. The highest hairy root production was with using internodes as explants. The transformation of hairy roots lines was confirmed by PCR detection of rolB gene. Half Murashige and Skoog (MS) medium was better for biomass production compared with MS medium. HPLC analysis of resveratrol production in the hairy root cultures showed that all the genotypes produced higher amounts of resveratrol than control roots. The highest amount of resveratrol was produced from W16 internode cultures, which was 31-fold higher than that of control root. Furthermore, TLC analysis showed that treatments of hairy roots with sodium acetate and jasmonate elevated resveratrol levels both in hairy root tissue and excreted into the half MS medium. These results demonstrate that endogenous and exogenous factors can affect resveratrol production in hairy root culture of grape, and this strategy could be used to increase low resveratrol production in grapes.

  12. [Effect of pH on suppressing the growth of other bacteria and fungi in culturing Phanerochaete chrysosporium in liquid medium].

    Science.gov (United States)

    Gao, Da-wen; Wen, Xiang-hua; Zhou, Xiao-yan; Zeng, Yong-gang; Qian, Yi

    2005-11-01

    Effect of different pH value on suppressing the growth of other bacteria and fungi in culturing Phanerochaete chrysosporium in liquid medium under non-sterile were investigated in agitated Erlenmeyer flasks. Results showed that nitrogen-limited liquid medium with pH3.6 and pH4.4 were contaminated only by yeast fungi when the Phanerochaete chrysosporium was incubated with spore inoculation under non-sterile condition for one day; however, nitrogen-limited liquid medium with pH5.6 was contaminated not only by yeast, but also by bacteria. These contaminated yeast and bacteria reduced the dye decolorizing ability of Phanerochaete chrysosporium . If after the Phanerochaete chrysosporium was incubated under sterile condition for 5 days, it can decolorize over 70% of the reactive brilliant red K-2BP within 45 hours under non-sterile condition, and this removal rate was close to or even higher than that under sterile condition. Phanerochaete chrysosporium cultured in the liquid medium with pH4.4 have the best decolorizing effect under non-sterile condition, and can decolorize up to 80% of the reactive brilliant red K-2BP in 24 hours. In additions, it was observed that by using the Phanerochaete chrysosporium incubated in above nitrogen-limited liquid medium with different pH under sterile condition for 5 days, the system were also contaminated by the other bacteria and yeast during decolorizing reactive brilliant red K-2BP under non-sterile condition, but the amount of these bacteria and yeast in liquid medium were too little to influence the Phanerochaete chrysosporium decolorizing reactive brilliant red K-2BP. So that, when Phanerochaete chrysosporium was used to decolorize reactive dyes under non-sterile condition, the incubation of Phanerochaete chrysosporium must be operated under sterile condition in order to achieve the higher decolorization.

  13. Optimization and Scale-up Isolation and Culture of Neonatal Porcine Islets: Potential for Clinical Application.

    Science.gov (United States)

    Ellis, Cara; Lyon, James G; Korbutt, Gregory S

    2016-01-01

    One challenge that must be overcome to allow transplantation of neonatal porcine islets (NPIs) to become a clinical reality is defining a reproducible and scalable protocol for the efficient preparation of therapeutic quantities of clinical grade NPIs. In our standard protocol, we routinely isolate NPIs from a maximum of four pancreases, requiring tissue culture in 16 Petri dishes (four per pancreas) in Ham's F10 and bovine serum albumin (BSA). We have now developed a scalable and technically simpler protocol that allows us to isolate NPIs from a minimum of 12 pancreases at a time by employing automated tissue chopping, collagenase digestion in a single vessel, and tissue culture/media changes in 75% fewer Petri dishes. For culture, BSA is replaced with human serum albumin and supplemented with Z-VAD-FMK general caspase inhibitor and a protease inhibitor cocktail. The caspase inhibitor was added to the media for only the first 90 min of culture. NPIs isolated using the scalable protocol had significantly more cellular insulin recovered (56.9 ± 1.4 µg) when compared to the standard protocol (15.0 ± 0.5 µg; p < 0.05). Compared to our standard protocol, recovery of β-cells (6.0 × 10(6) ± 0.2 vs. 10.0 × 10(6) ± 0.4; p < 0.05) and islet equivalents (35,135 ± 186 vs. 41,810 ± 226; p < 0.05) was significantly higher using the scalable protocol. During a static glucose stimulation assay, the SI of islets isolated by the standard protocol were significantly lower than the scale-up protocol (4.3 ± 0.2 vs. 5.5 ± 0.1; p < 0.05). Mice transplanted with NPIs using the scalable protocol had significantly lower blood glucose levels than the mice that receiving NPIs from the standard protocol (p < 0.01) and responded significantly better to a glucose tolerance test. Based on the above findings, this improved simpler scalable protocol is a significantly more efficient means for preparing therapeutic quantities

  14. [Is it possible to "cancel" aging process of cell cultures under optimal conditions for cultivation?].

    Science.gov (United States)

    Bozhkov, A I; Kovaleva, M K; Menzianova, N G

    2011-01-01

    The characteristics of the cells epigenotypes Dunaliella viridis Teod. in the process of chronological and replicative aging were investigated. By 40th day of accumulative cultivation (which coincided with the stationary growth phase) DNA content in the cells of Dunaliella viridis increased 2 times, triacylglycerides 3 times, beta-carotene and carbonyl proteins 2 times, RNA content decreased in comparison with cells in exponential growth phase, i. e., the 40th day of growth of culture forms the age-related epigenotype. 4 received subcultures were being transplanted during 2 years in mid-logarithmic growth phase (subculture-10), early stationary phase of growth (subculture-20), in the mid-stationary growth phase (subculture-30), and late stationary growth phase (subculture-40). It is shown that epigenotype of subculture-10 remained unchanged over 2 years of cultivation, i. e., it does not manifest replicative aging. At the same time, the subculture-20, although long enough (at least 40 passages), maintained epigenotype characteristic of young cultures, and showed age-related changes. Pronounced age-dependent changes of epigenotype in the course of cultivation were identified for subculture-30, and subculture-40 was characterized by unstable epigenotype. Thus, cultivation conditions determine the intensity of replicative aging in Dunaliella viridis.

  15. Production and optimization of L-glutaminase enzyme from Hypocrea jecorina pure culture.

    Science.gov (United States)

    Bülbül, Dilara; Karakuş, Emine

    2013-01-01

    L-Glutaminase (L-glutamine amidohydrolase, EC 3.5.1.2) is the important enzyme that catalyzes the deamination of L-glutamine to L-glutamic acid and ammonium ions. Recently, L-glutaminase has received much attention with respect to its therapeutic and industrial applications. It acts as a potent antileukemic agent and shows flavor-enhancing capacity in the production of fermented foods. Glutaminase activity is widely distributed in plants, animal tissues, and microorganisms, including bacteria, yeasts, and fungi. This study presents microbial production of glutaminase enzyme from Hypocrea jecorina pure culture and determination of optimum conditions and calculation of kinetic parameters of the produced enzyme. The optimum values were determined by using sa Nesslerization reaction for our produced glutaminase enzyme. The optimum pH value was determined as 8.0 and optimum temperature as 50°C for the glutaminase enzyme. The Km and Vmax values, the kinetic parameters, of enzyme produced from Hypocrea jecorina, pure culture were determined as 0.491 mM for Km and 13.86 U/L for Vmax by plotted Lineweaver-Burk graphing, respectively. The glutaminase enzyme from H. jecorina microorganism has very high thermal and storage stability.

  16. Optimization of exopolysaccharides production from a novel strain of Ganoderma lucidum CAU5501 in submerged culture

    Directory of Open Access Journals (Sweden)

    Baojing Yuan

    2012-06-01

    Full Text Available This study aimed at optimizing the medium of a new Ganoderma lucidum strain CAU5501 to enhance the yield of exopolysaccharides (EPS and mycelial growth. Firstly, the suitable level of glucose, magnesium, phosphate and C/N ratio was determined by single factor experiment. Subsequently, the optimum concentrations of these medium components were investigated using the orthogonal matrix method. The results indicated that the higher levels of EPS were correlated with the level of cell growth when glucose concentration was studied (data no show. The optimum medium for EPS yield was found to be 70 g/l glucose, 5 C/N ratio, 2.5 g/l KH2PO4, 0.75 g/l MgSO4·7H2O, and for mycelial growth was 50 g/l glucose, 5 C/N ratio, 1.5 g/l KH2PO4, 0.5 g/l MgSO4·7H2O. When cultivated in the obtained optimal media in 3 L shake flask, compared to the basal medium, the EPS yield increased markedly from 1.003 to 1.723 g/l, and the mycelium formation was also markedly improved from 2.028 to 7.235 g/l. Results obtained in this study are beneficial to further study for enhancing the production of Ganoderma lucidum polysaccharides in large scale commercialized production.

  17. Optimization of culture conditions for hydrogen production by Ethanoligenens harbinense B49 using response surface methodology.

    Science.gov (United States)

    Guo, Wan-Qian; Ren, Nan-Qi; Wang, Xiang-Jing; Xiang, Wen-Sheng; Ding, Jie; You, Yang; Liu, Bing-Feng

    2009-02-01

    The design of an optimum and cost-efficient medium for high-level production of hydrogen by Ethanoligenens harbinense B49 was attempted by using response surface methodology (RSM). Based on the Plackett-Burman design, Fe(2+) and Mg(2+) were selected as the most critical nutrient salts. Subsequently, the optimum combination of the selected factors and the sole carbon source glucose were investigated by the Box-Behnken design. Results showed that the maximum hydrogen yield of 2.21 mol/mol glucose was predicted when the concentrations of glucose, Fe(2+) and Mg(2+) were 14.57 g/L, 177.28 mg/L and 691.98 mg/L, respectively. The results were further verified by triplicate experiments. The batch reactors were operated under an optimized condition of the respective glucose, Fe(2+) and Mg(2+) concentration of 14.5 g/L, 180 mg/L and 690 mg/L, the initial pH of 6.0 and experimental temperature of 35+/-1(o)C. Without further pH adjustment, the maximum hydrogen yield of 2.20 mol/mol glucose was obtained based on the optimized medium with further verified the practicability of this optimum strategy.

  18. Ultra-high performance liquid chromatographic determination of levofloxacin in human plasma and prostate tissue with use of experimental design optimization procedures.

    Science.gov (United States)

    Szerkus, O; Jacyna, J; Wiczling, P; Gibas, A; Sieczkowski, M; Siluk, D; Matuszewski, M; Kaliszan, R; Markuszewski, M J

    2016-09-01

    Fluoroquinolones are considered as gold standard for the prevention of bacterial infections after transrectal ultrasound guided prostate biopsy. However, recent studies reported that fluoroquinolone- resistant bacterial strains are responsible for gradually increasing number of infections after transrectal prostate biopsy. In daily clinical practice, antibacterial efficacy is evaluated only in vitro, by measuring the reaction of bacteria with an antimicrobial agent in culture media (i.e. calculation of minimal inhibitory concentration). Such approach, however, has no relation to the treated tissue characteristics and might be highly misleading. Thus, the objective of this study was to develop, with the use of Design of Experiments approach, a reliable, specific and sensitive ultra-high performance liquid chromatography- diode array detection method for the quantitative analysis of levofloxacin in plasma and prostate tissue samples obtained from patients undergoing prostate biopsy. Moreover, correlation study between concentrations observed in plasma samples vs prostatic tissue samples was performed, resulting in better understanding, evaluation and optimization of the fluoroquinolone-based antimicrobial prophylaxis during transrectal ultrasound guided prostate biopsy. Box-Behnken design was employed to optimize chromatographic conditions of the isocratic elution program in order to obtain desirable retention time, peak symmetry and resolution of levofloxacine and ciprofloxacine (internal standard) peaks. Fractional Factorial design 2(4-1) with four center points was used for screening of significant factors affecting levofloxacin extraction from the prostatic tissue. Due to the limited number of tissue samples the prostatic sample preparation procedure was further optimized using Central Composite design. Design of Experiments approach was also utilized for evaluation of parameter robustness. The method was found linear over the range of 0.030-10μg/mL for human

  19. Development and validation of a liquid medium (M7H9C) for routine culture of Mycobacterium avium subsp. paratuberculosis to replace modified Bactec 12B medium.

    Science.gov (United States)

    Whittington, Richard J; Whittington, Ann-Michele; Waldron, Anna; Begg, Douglas J; de Silva, Kumi; Purdie, Auriol C; Plain, Karren M

    2013-12-01

    Liquid culture of Mycobacterium avium subsp. paratuberculosis from clinical samples, such as feces, is the most sensitive antemortem test for the diagnosis of Johne's disease in ruminants. In Australia, New Zealand, the United States, and some other countries, the Bactec 460 system with modified Bactec 12B medium (Becton, Dickinson) has been the most commonly used liquid culture system, but it was discontinued in 2012. In this study, a new liquid culture medium, M7H9C, was developed. It consists of a Middlebrook 7H9 medium base with added Casitone, albumin, dextrose, catalase, egg yolk, mycobactin J, and a cocktail of antibiotics. We found that polyoxyethylene stearate (POES) was not essential for the cultivation of M. avium subsp. paratuberculosis in either the Bactec 12B or the M7H9C medium. The limit of detection determined using pure cultures of the C and S strains of M. avium subsp. paratuberculosis was 7 bacilli per 50 μl inoculum in the two media. The new medium was validated using 784 fecal and tissue samples from sheep and cattle, >25% of which contained viable M. avium subsp. paratuberculosis. Discrepant results for the clinical samples between the two media were mostly associated with samples that contained <10 viable bacilli per gram, but these results were relatively uncommon, and the performances of the two media were not significantly different. M7H9C medium was less than half the cost of the Bactec 12B medium and did not require regular examination during incubation, but a confirmatory IS900 PCR test had to be performed on every culture after the predetermined incubation period.

  20. Determination of the structure factor of simple liquid metals from the pseudopotential theory and optimized random-phase approximation: Application to Al and Ga

    Science.gov (United States)

    Bretonnet, J. L.; Regnaut, C.

    1985-04-01

    We present the results of calculations of the static structure factor S(q) of liquid Al and Ga at the melting point. These calculations were motivated because many simple liquid metals exhibit structure anomalies taking the form of a shoulder on the main peak or even an asymmetry in the peak itself, while other liquid metals are correctly predicted by the standard models of liquid structure. Al and Ga have similar valence, electronic density, and size of their ionic radius; therefore, their pair potentials are somewhat similar. Despite this, their structure factors display most of the differences that can be observed among the variety of liquid metals. Starting from the Shaw optimized model potential [Phys. Rev. 174, 769 (1968)], a pair potential is constructed. A comparative examination of the electron-gas response function of Vashishta and Singwi [Phys. Rev. B 6, 875 (1972)] and of Ichimaru and Utsumi [Phys. Rev. B 24, 7385 (1981)] is carried out. Different depletion hole distributions are also used and full nonlocality is taken into account through effective masses. So S(q) is calculated by means of the optimized random-phase approximation. Particular attention is also devoted to the low-q region. By comparison with Monte Carlo computation, we show the limitation of various thermodynamic perturbation methods, such as the random-phase approximation or the soft-sphere model. The study of S(q) provides a stringent test of the model potential, where the electron-ion pseudopotential and the local-field correction are of prime importance, but where effective masses and depletion hole distribution may also have a role to play.

  1. Optimization of liquid chromatographic method for the separation of nine hydrophilic and hydrophobic components in Salviae miltiorrhizae Radix et Rhizoma (Danshen) using microemulsion as eluent.

    Science.gov (United States)

    Huang, Hongzhang; Xuan, Xueyi; Xu, Liyuan; Yang, Jianrui; Gao, Chongkai; Li, Ning

    2014-04-01

    In this study, we have proposed and developed a novel, environmental-friendly and simple method for separation of nine hydrophilic and hydrophobic components in Danshen using microemulsion liquid chromatography. The proposed method was optimized via the preliminary screening experiment and the experimental design. The following factors were investigated in preliminary screening experiment: pH of mobile phase, column type, the nature of surfactant, the nature of oil phase and additives. In order to simultaneously optimize resolution and analysis time, the chromatographic optimization function (COF) was adopted to evaluate chromatograms. The central composite design (CCD) was used to create the matrix of experiments for mapping the chromatographic response surface. Finally, the COF values were fitted into a second order polynomial model and the response surface methodology (RSM) was employed to find the optimal eluent constituents. The reliability of the established model was confirmed by the good agreement obtained between experimental data and predictive values. Based on the results from the preliminary screening experiment and the CCD optimization, the optimal mobile phase was identified as a solution consisting of 6.68% (w/w) polyoxyethylene lauryl ether (Brij35), 0.84% (w/w) cyclohexane, 6.92% (w/w) n-butanol, 85.56% (w/w) phosphate buffer (pH 6.60) and 8mM cetyltrimethyl ammonium bromide (CTAB). Copyright © 2014 Elsevier B.V. All rights reserved.

  2. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  3. Vapour–liquid equilibria of the OPLS (Optimized Potentials for Liquid Simulations model for binary systems of alkanes and alkanes + alcohols

    Directory of Open Access Journals (Sweden)

    SLOBODAN P. SERBANOVIC

    2005-03-01

    Full Text Available The NpT - Gibbs ensemble Monte Carlo computer simulationmethod was applied to predict the vapour–liquid equlibrium (VLE behavior of the binary systems ethane + pentane at 277.55 K and 310.95 K, ethane + hexane at 298.15 K, propane + methanol at 313.15 K and propane + ethanol at 325.15 K and 425.15 K. The optimised potentials for the liquid simulating (OPLS model were used to describe the interactions of alkanes and alcohols. The simulated VLE predictions are compared with experimental data available for the pressure and phase composition of the analyzed binary systems. The agreement between the experimental data and the simulation results is found to be generally good, although slightly better for system in which both components were nonpolar.

  4. Optimal isolation and xeno-free culture conditions for limbal stem cell function.

    Science.gov (United States)

    Stasi, Kalliopi; Goings, DaVida; Huang, Jiayan; Herman, Lindsay; Pinto, Filipa; Addis, Russell C; Klein, Dahlia; Massaro-Giordano, Giacomina; Gearhart, John D

    2014-01-20

    To preserve limbal stem cell (LSC) function in vitro with xenobiotic-free culture conditions. Limbal epithelial cells were isolated from 139 donors using 15 variations of three dissociation solutions. All culture conditions were compared to the baseline condition of murine 3T3-J3 feeders with xenobiotic (Xeno) keratinocyte growth medium at 20% O2. Five Xeno and Xeno-free media with increasing concentrations of calcium and epidermal growth factor (EGF) were evaluated at 5%, 14%, and 20% O2. Human MRC-5, dermal (fetal, neonatal, or adult), and limbal stromal fibroblasts were compared. Statistical analysis was performed on the number of maximum serial weekly passages, percentage of aborted colonies, colony-forming efficiency (CFE), p63α(bright) cells, and RT-PCR ratio of p63α/K12. Immunocytochemistry and RT-PCR for p63α, ABCG2, Bmi1, C/EBPδ , K12, and MUC1 were performed to evaluate phenotype. Dispase/TrypLE was the isolation method that consistently showed the best yield, viability, and CFE. On 3T3-J2 feeders, Xeno-free medium with calcium 0.1 mM and EGF 10 ng/mL at 20% O2 supported more passages with equivalent percentage of aborted colonies, p63α(bright) cells, and p63α/K12 RT-PCR ratio compared to baseline Xeno-media. With this Xeno-free medium, MRC-5 feeders showed the best performance, followed by fetal, neonatal, adult HDF, and limbal fibroblasts. MRC-5 feeders supported serial passages with sustained high expression of progenitor cell markers at levels as robust as the baseline condition without significant difference between 20% and 5% O2. The LSC function can be maintained in vitro under appropriate Xeno-free conditions.

  5. Optimize the modulation response of twisted-nematic liquid crystal displays as pure phase spatial light modulators

    Science.gov (United States)

    Ma, Baiheng; Peng, Fei; Kang, Mingwu; Zhou, Jiawu

    2014-11-01

    Twisted-nematic liquid crystal displays (TN-LCD) are widely used in numerous research fields of optics working as spatial light modulators. Approaches to obtaining desired intensity or phase modulation by TN-LCD have been extensively studied based on the knowledge of TN-LCD's internal structure parameters, e.g., the orientation of LC molecules at the surfaces, the twist angle, the thickness of the LC layer, and the birefringence of the material. Generally TN-LCD placed between two linear polarizers (P) produces coupled intensity and phase modulation. To obtain the commonly used pure phase modulation, quarter wave plates (QWP) are often used in front of and/or behind the LCD. In this paper, we present a method to optimize the optical modulation properties of the TN-LCD to obtain pure phase modulation in the configuration of P-QWP-LCD-QWP-P each with proper orientation. Firstly an improved method for determining the Jones matrix of the TN-LCD without knowing its internal parameters is presented, which is based on the macroscopical Jones matrix descriptions for TN-LCD, linear polarizer and QWP. Only three sets of intensity measurements are needed for the complete determination of the TN-LCD's Jones matrix for a single wavelength. Then Jones matrix calculations are carried out to determine the orientations of the polarizers and QWPs for pure phase modulation response. In addition, we prove that the phase modulation depth (PMD) of the TN-LCD can be further increased provided that the mean intensity transmission is decreased to a lower level, which is very useful when the TN-LCD is used as a phase modulator and the ratio between the intensities of the desired diffracted order relative to the other diffracted orders is required higher. Experimental results coincide well with the optical modulation properties of the TN-LCD predicted by our determined Jones matrix. In contrast to the traditional method which requires knowledge of the TN-LCD's internal structure parameters

  6. PLASTIC WASTE CONVERSION TO LIQUID FUELS OVER MODIFIED-RESIDUAL CATALYTIC CRACKING CATALYSTS: MODELING AND OPTIMIZATION USING HYBRID ARTIFICIAL NEURAL NETWORK – GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    Istadi Istadi

    2012-04-01

    Full Text Available The plastic waste utilization can be addressed toward different valuable products. A promising technology for the utilization is by converting it to fuels. Simultaneous modeling and optimization representing effect of reactor temperature, catalyst calcinations temperature, and plastic/catalyst weight ratio toward performance of liquid fuel production was studied over modified catalyst waste. The optimization was performed to find optimal operating conditions (reactor temperature, catalyst calcination temperature, and plastic/catalyst weight ratio that maximize the liquid fuel product. A Hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA method was used for the modeling and optimization, respectively. The variable interaction between the reactor temperature, catalyst calcination temperature, as well as plastic/catalyst ratio is presented in surface plots. From the GC-MS characterization, the liquid fuels product was mainly composed of C4 to C13 hydrocarbons.KONVERSI LIMBAH PLASTIK MENJADI BAHAN BAKAR CAIR DENGAN METODE PERENGKAHAN KATALITIK MENGGUNAKAN KATALIS BEKAS YANG TERMODIFIKASI: PEMODELAN DAN OPTIMASI MENGGUNAKAN GABUNGAN METODE ARTIFICIAL NEURAL NETWORK DAN GENETIC ALGORITHM. Pemanfaatan limbah plastik dapat dilakukan untuk menghasilkan produk yang lebih bernilai tinggi. Salah satu teknologi yang menjanjikan adalah dengan mengkonversikannya menjadi bahan bakar. Permodelan, simulasi dan optimisasi simultan yang menggambarkan efek dari suhu reaktor, suhu kalsinasi katalis, dan rasio berat plastik/katalis terhadap kinerja produksi bahan bakar cair telah dipelajari menggunakan katalis bekas termodifikasi Optimisasi ini ditujukan untuk mencari kondisi operasi optimum (suhu reaktor, suhu kalsinasi katalis, dan rasio berat plastik/katalis yang memaksimalkan produk bahan bakar cair. Metode Hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA telah digunakan untuk permodelan dan optimisasi simultan tersebut. Inetraksi antar variabel

  7. Screening of phenylpyruvic acid producers and optimization of culture conditions in bench scale bioreactors.

    Science.gov (United States)

    Coban, Hasan B; Demirci, Ali; Patterson, Paul H; Elias, Ryan J

    2014-11-01

    Alpha keto acids are deaminated forms of amino acids that have received significant attention as feed and food additives in the agriculture and medical industries. To date, their production has been commonly performed at shake-flask scale with low product concentrations. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was investigated. First, various microorganisms were screened to select the most efficient producer. Thereafter, growth parameters (temperature, pH, and aeration) were optimized in bench scale bioreactors to maximize both PPA and biomass concentration in bench scale bioreactors, using response surface methodology. Among the four different microorganisms evaluated, Proteus vulgaris was the most productive strain for PPA production. Optimum temperature, pH, and aeration conditions were determined as 34.5 °C, 5.12, and 0.5 vvm for PPA production, whereas 36.9 °C, pH 6.87, and 0.96 vvm for the biomass production. Under these optimum conditions, PPA concentration was enhanced to 1,054 mg/L, which was almost three times higher than shake-flask fermentation concentrations. Moreover, P. vulgaris biomass was produced at 3.25 g/L under optimum conditions. Overall, this study demonstrated that optimization of growth parameters improved PPA production in 1-L working volume bench-scale bioreactors compared to previous studies in the literature and was a first step to scale up the production to industrial production.

  8. Improving the efficiency of isolated microspore culture in six-row spring barley: I-optimization of key physical factors.

    Science.gov (United States)

    Esteves, Patricio; Belzile, François

    2014-06-01

    An improved isolated microspore culture protocol alleviating the recalcitrance typically observed in six-row spring barley was developed by optimizing four key physical factors to increase embryogenesis and reduce albinism. Doubled haploid (DH) plants are completely homozygous individuals that can be generated in just a few months via androgenesis in vitro. DHs are useful tools in genetic research and in plant breeding. Isolated microspore culture (IMC) is the most efficient way to produce DHs, but a strong genotype dependency imposes limitations to its wide application. Six-row, spring barley genotypes are considered as particularly recalcitrant due to a low frequency of embryogenesis and a high rate of albinism. Seeking to develop an efficient IMC protocol for this type of barley, we explored four important factors: (1) the harvest stage of immature spikes, (2) the type of pretreatment applied, (3) the osmotic potential in the induction medium, and (4) the plating density of microspores. This work was first performed using four barley genotypes: two typical six-row spring cultivars (ACCA and Léger), a two-row spring (Gobernadora) and a two-row winter (Igri) cultivar. First, by optimizing the harvest stage for each genotype we obtained a twofold to fourfold increase in the yield of embryogenic microspores. Second, two pretreatments (0.3 M mannitol for 2 days, or a combination of cold and heat over 15 days) both performed significantly better than the commonly used cold pretreatment (28 days at 4 °C). Third, an induction medium-containing mannitol (32 g/l) doubled green plant regeneration. Fourth, a plating density of 10(6) microspores/ml yielded the highest number of green regenerated plants. Our most important findings were then confirmed using sets of F1s from a six-row, spring-type breeding program.

  9. Molecular characterization of forest soil based Paenibacillus elgii and optimization of various culture conditions for its improved antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Dileep eKumar BS

    2015-10-01

    Full Text Available Microorganisms have provided a bounty of bioactive secondary metabolites with very exciting biological activities such as antibacterial, antifungal antiviral, and anticancer, etc. The present study aims at the optimization of culture conditions for improved antimicrobial production of Paenibacillus elgii obtained from Wayanad forest of Western Ghats region of Kerala, India. A bacterial strain isolated from the Western Ghats forest soil of Wayanad, Kerala, India was identified as P. elgii by 16S rRNA gene sequencing. P. elgii recorded significant board spectrum activity against all human and plant pathogenic microorganism tested except Candida albicans. It has been well known that even minor variations in the fermentation medium may impact not only the quantity of desired bioactive metabolites but also the general metabolic profile of the producing microorganisms. Thus, further studies were carried out to assess the impact of medium components on the antimicrobial production of P. elgii and to optimize an ideal fermentation medium to maximize its antimicrobial production. Out of three media [nutrient broth (NA, Luria broth (LB and Trypticase soy broth (TSB] used for fermentation, TSB medium recorded significant activity. Glucose and meat peptone were identified as the best carbon and nitrogen sources, which significantly affected the antibiotic production when supplemented with TSB medium. Next the effect of various fermentation conditions such as temperature, pH and incubation time on the production of antimicrobial compounds was studied on TSB+glucose+meat peptone and an initial pH of 7 and a temperature of 30ºC for 3 days were found to be optimum for maximum antimicrobial production. The results indicate that medium composition in the fermentation media along with cultural parameters plays a vital role in the enhanced production of antimicrobial substances.

  10. 基于供应曲线的最优变现策略研究%Research on optimal liquidation strategy based on supply curve

    Institute of Scientific and Technical Information of China (English)

    胡小平; 何建敏

    2011-01-01

    基于供应曲线理论研究了机构投资者的最优变现策略问题.首介绍了供应曲线的相关理论.利用供应曲线,给出了变现策略与变现成本的数学描述.基于极大值原理,获得了问题的解析解,并对经济意义进行了阐述.研究结果表明,当变现速度不受限制时,机构投资者应先买入头寸,到某一时点后,即开始卖出头寸,并且卖出的速度变化量是越来越小,最终以接近恒定速度卖清手中所有的头寸;变现速度受限时,机构投资者应先以较小的速度卖出头寸,逐渐增大卖出速度,直到最大卖出速度,再以较小的速度卖清手中头寸.%The optimal liquidation strategies of the institution investor are investigated based on supply curves.Firstly, the theory on supply curve is introduced. Secondly, the liquidation strategy and liquidation cost are provided by utilizing the supply curve. Furthermore, the analytic solucion of this problem is obtained based on the maximum principle. Finally, the solution is expatiated in the sense of economic. The result of this paper shows that the institution investor should buy the positions first and then start to sell the positions held after a certain point, furthermore, the change quantity of liquidating speed is smaller and smaller, and ultimately,liquidate all positions held with approximately constant speed if the liquidating speed is not limited. Otherwise,the institution investor should sell the positions held with a slower speed is reached, and then augment gradually the liquidating speed until a maximum liquidating speed, and then liquidate all positions held with a slower speed.

  11. Rapid High Performance Liquid Chromatography Determination and Optimization of Extraction Parameters of the α-Asarone Isolated from Perilla frutescens L.

    Science.gov (United States)

    Hwang, Seung Hwan; Kwon, Shin Hwa; Kang, Young-Hee; Lee, Jae-Yong; Lim, Soon Sung

    2017-02-10

    Response surface methodology (RSM), based on a central composite design, was used to determine the best liquid-to-raw material ratio (10:3-15 mL/g), extraction time (1-3 h), and ethanol concentration (50%-100%) for maximum content of α-asarone from Perilla frutescens (PF) extract. Experimental values of α-asarone were 9.51-46.36 mg/g; the results fitted a second-order quadratic polynomial model and correlated with the proposed model (R2 > 0.9354). The best conditions were obtained with extraction time of 1.76 h, liquid-to-raw material ratio of 10:13.5 mL/g, and ethanol concentration of 90.37%. Under these conditions, the model predicted extraction content of 40.56 mg/g, while experimental PF content of α-asarone was 43.84 mg/g dried plant. Optimized conditions determined for maximum content of α-asarone were similar to the experimental range. Experimental values agreed with those predicted, thus validating and indicating suitability of both the model and the RSM approach for optimizing extraction conditions. In addition, a reliable, reproducible and accurate method for the quantitative determination of α-asarone by High Performance Liquid Chromatography (HPLC) analysis was developed with limit of detection (LOD), limit of quantitation (LOQ) values of 0.10 and 0.29 µg/mL and excellent linearity (R2 > 0.9999).

  12. Antimicrobial and Antioxidant Activities and Effect of 1-Hexadecene Addition on Palmarumycin C2 and C3 Yields in Liquid Culture of Endophytic Fungus Berkleasmium sp. Dzf12

    Directory of Open Access Journals (Sweden)

    Yan Mou

    2013-12-01

    Full Text Available Two spirobisnaphthalenes, namely palmarumycins C2 and C3, were isolated from cultures of the endophytic fungus Berkleasmium sp. Dzf12 after treatment with 1-hexadecene. After addition of 1-hexadecene at 10% to the medium on day 6 of culture, the maximal yields of palmarumycins C2 and C3 were obtained as 0.40 g/L and 1.19 g/L, which were 40.00 fold and 59.50 fold higher, respectively, in comparison with those of the control (0.01 g/L and 0.02 g/L. The results indicated that addition of 1-hexadecene can be an effective strategy for enhancing the production of palmarumycins C2 and C3 in liquid culture of endophytic fungus Berkleasmium sp. Dzf12. Palmarumycin C3 exhibited stronger antimicrobial and antioxidant activities than palmarumycin C2.

  13. Biological synthesis of very small silver nanoparticles by culture supernatant of Klebsiella pneumonia: The effects of visible-light irradiation and the liquid mixing process

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, Narges [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Daneshpajouh, Shahram; Seyedbagheri, Seyedali; Atashdehghan, Reza [Hydrometallurgy Research Unit, Research and Development Center, National Iranian Copper Industries Company, Sarcheshmeh, Rafsanjan (Iran, Islamic Republic of); Abdi, Khosro [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sarkar, Saeed [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Minaian, Sara [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Hamid Reza [Department of Material Science, Faculty of Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: shahverd@sina.tums.ac.ir [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2009-06-03

    This study has investigated different visible-light irradiation's effect on the formation of silver nanoparticles from silver nitrate using the culture supernatant of Klebsiella pneumonia. Our study shows that visible-light emission can significantly prompt the synthesis of silver nanoparticles. Also, the study experimentally investigated the liquid mixing process effect on silver nanoparticle synthesis by visible-light irradiation. This study successfully synthesized uniformly dispersed silver nanoparticles with a uniform size and shape in the range of 1-6 nm with an average size of 3 nm. Furthermore, the study investigated the mechanism of the reduction of silver ions by culture supernatant of K. pneumonia, and used X-ray diffraction to characterize silver chloride as an intermediate compound. Silver chloride was prepared synthetically and used as a substrate for the synthesis of silver nanoparticles by culture supernatant of K. pneumonia. The silver nanoparticles have been prepared from silver chloride during this investigation for the first time.

  14. Optimization of Cultured Human Corneal Endothelial Cell Sheet Transplantation and Post-Operative Sheet Evaluation in a Rabbit Model.

    Science.gov (United States)

    Yamaguchi, Masahiro; Shima, Nobuyuki; Kimoto, Miwa; Ebihara, Nobuyuki; Murakami, Akira; Yamagami, Satoru

    2016-09-01

    To optimize cultured human corneal endothelial cell (cHCEC) sheet transplantation technique for maintenance of cHCEC viability. cHCEC sheets cultured on a collagen scaffold were covered with or without Viscoat® and exposed to humidified air in the incubator. cHCEC sheets with or without Viscoat® were transplanted into cadaveric porcine eyes by the DSAEK technique with full air tamponade and incubated for various time periods. Then cell viability was determined by using the live/dead assay kit. cHCEC sheets with Viscoat® were transplanted into rabbit eyes and the sheets were histologically evaluated before and 14 days after transplantation. A collagen scaffold and Viscoat® were effective for protecting cHCEC from damage due to air exposure in vitro. All cells died after 18 hours of air exposure in porcine eyes in Viscoat® untreated control. In contrast, Viscoat® treatment sustained full cell viability following 2 hours and could maintain approximately 80% viability after 18 hours. In a rabbit model, transplanted cHCEC sheet with Viscoat® maintained cell density at 2803 ± 229 mm(2) (18% cell loss) and expression of N-cadherin, zonula occludens-1, and actin-filament localized to cell boundary as similar as donor HCEC. Viscoat® can contribute to cHCEC protection from damage caused by exposure to air.

  15. Direct fermentation of xylan by Clostridium strain BOH3 for the production of butanol and hydrogen using optimized culture medium.

    Science.gov (United States)

    Rajagopalan, Gobinath; He, Jianzhong; Yang, Kun Lin

    2014-02-01

    Clostridium strain BOH3 is able to utilize 10 g/l of xylan in reinforced clostridial medium (RCM) and produce butanol and hydrogen. However, increasing xylan concentration to 30 g/l does not enhance the production of butanol and hydrogen due to insufficient expression of xylanase enzyme (27.5 U/mg). To enhance the xylanase activity, an optimized culture medium (OCM), which consists of sugarcane bagasse hydrolysate (11.75 g/l), ammonium sulfate (8.92 g/l) and iron (III) chloride (1.45 mM) is designed. In the optimized OCM, Clostridium strain BOH3 expresses more xylanase and shows higher xylanase activity (44.05 ± 0.25 U/mg) in the OCM. This activity is about 1.6-fold higher than that in the original RCM. Employing OCM as a medium, Clostridium strain BOH3 effectively ferments high concentration (30 and 50 g/l) of xylan and produces 12.05 ± 0.15 and 14.80 ± 0.15 g/l of butanol and 1.78 ± 0.08 and 2.65 ± 0.15 l/l of hydrogen, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Optimization of Culture Conditions and Inducers for Improved Protease Production by Penicillium griseofulvum LCJ231 under Submerged Fermentation

    Directory of Open Access Journals (Sweden)

    X. Josephine Jenitta

    2015-04-01

    Full Text Available The production of protease by Penicillium griseofulvum LCJ231 under submerged fermentation was studied with an objective to improve the production through medium optimization. Important nutritional and physical parameters were optimized for maximizing the protease production. The most suitable carbon source, nitrogen source and inducer for maximizing the protease production were studied. It was found that starch, yeast extract and casein were the suitable carbon source, nitrogen source and inducer respectively. The present study also explored the utilization of several agro-wastes as low-cost natural inducers for protease production. The addition of black gram husk as an inducer successfully enhanced the protease production (145.12 U/mL. Maximum production of the protease enzyme was found in the culture medium with initial medium pH of 8 and 2 g/L of inoculum. The results obtained in the present study demonstrate the potential use of the cheap and abundantly available black gram husk for the induction of proteases and thus offer a new approach for industrial enzyme production.

  17. Effects of sodium sulfate on the freshwater microalga Chlamydomonas moewusii: implications for the optimization of algal culture media.

    Science.gov (United States)

    Mera, Roi; Torres, Enrique; Abalde, Julio

    2016-02-01

    The study of the microalgal growth kinetics is an indispensable tool in all fields of phycology. Knowing the optimal nutrient concentration is an important issue that will help to develop efficient growth systems for these microorganisms. Although nitrogen and phosphorus are well studied for this purpose, sulfur seems to be less investigated. Sulfate is a primary sulfur source used by microalgae; moreover, the concentration of this compound is increasing in freshwater systems due to pollution. The aim of this study was to investigate the effects of different sodium sulfate concentrations in the culture medium on growth and growth kinetics of the freshwater microalga Chlamydomonas moewusii. Production of biomass, chl content, kinetic equations, and a mathematical model that describe the microalgal growth in relation with the concentration of sodium sulfate were obtained. The lowest concentration of sodium sulfate allowing optimal growth was 0.1 mM. Concentrations higher than 3 mM generated a toxic effect. This work demonstrates that this toxic effect was not directly due to the excess of sulfate ion but by the elevation of the ionic strength. An inhibition model was successfully used to simulate the relationship between specific growth rate and sodium sulfate in this microalga.

  18. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  19. Isolation, culture optimization and physico-chemical characterization of laccase enzyme from Pleurotus fossulatus.

    Science.gov (United States)

    Chowdhury, P; Hari, R; Chakraborty, B; Mandal, B; Naskar, S; Das, Nirmalendu

    2014-01-15

    Pleurotus fossulatus (Cooke) Sace is member of oyster mushroom can produced extracellular laccase (benzenediol: oxygen oxidoreductase; EC 1.10.3.2) in submerged fermentation. To analyze the optimum production for laccase P. fossulatus was cultured both in stationary and shaking condition in different media. Partial purification of laccase was done after 0-80% ammonium sulphate precipitation, followed by DEAE (Diethylaminoethyl) Sephadex (A-50) anion exchange chromatography. Potato-sucrose peptone (PSP) medium and Potato-dextrose (PD) medium showed highest laccase production in shaking and stationary conditions, respectively. Though the time required for optimum laccase production in stationary condition was much more than the shaking condition but the amount of laccase was about 2.75t greater in former condition. The laccase produced in stationary condition was more stable than the enzyme produced in shaking condition. The partially purified enzyme showed highest affinity towards o-dianisidine than guaiacol and ABTS (2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) as evidenced by their K(m). The physico-chemical properties of the laccase suggested the significance of this enzyme in industrial applications.

  20. [Optimization of culture conditions for in vitro rooting of argan (Argania spinosa L.)].

    Science.gov (United States)

    Bousselmame, F; Kenny, L; Chlyah, H

    2001-11-01

    The root system produced of in vitro organ plantlets is of poor quality and not efficient for the transfer to out-door conditions. To overcome such problems, experimentation was undertaken where the effects of growth regulators, nitrogen, sugar, activated charcoal and coconut fiber were tested on root induction and elongation. Modified Murashige and Skoog with half strength salt was used as a basal medium. Root induction (85%) with a mean of 16 roots per explant was obtained when shoots were grown, under dark conditions for 14 days, with a combination of two auxins (IBA and NNA), added at equal concentrations (5 mg.L-1). Secondary roots, 10 cm long, were initiated in 12% of the cultures in presence of 5 g.L-1 activated charcoal. Further improvements in the growth of the primary and secondary roots were obtained when semi-solid medium was substituted with a substrate composed of coconut fibers (80 g) mixed with semi-solid medium (35 mL) and agar (2.5 g.L-1).

  1. Motivation for physical culture as factor of students’ functional state optimization

    Directory of Open Access Journals (Sweden)

    Lachno O.G.

    2015-10-01

    Full Text Available Purpose: to analyze students’ attitude to physical education classes; to compare motivation for physical education of 1 st and 4 th year students. Material: 100 students of 17 - 22 years’ age participated in the research. All they were questioned. Results: In the whole, boys have positive attitude to sport practicing but some of them can have harmful habits. The attitude to sport practicing of most of girls changes with age. It was found that biological age of students significantly exceeds passport age. Biological age of senior students it reduces to some extent, in comparison with junior students. It was also found that in process of studying at HEE students’ motivation for sport practicing changes to positive side. It witnesses about formation of student positive attitude to physical education in general. Conclusions: we have shown that there is a demand in strengthening of motivation for physical culture classes and further formation positive attitude to them with increasing of students’ knowledge about physical education.

  2. Optimized Composition of Functional Bacteria for Bioremediation of Sediment Environment of Shrimp Culture

    Institute of Scientific and Technical Information of China (English)

    李秋芬; 辛福言; 邹玉霞; 陈民山; 唐启升

    2004-01-01

    After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multistrain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single-strain groups. Three-strain groups are better than two-strain groups, and fourstrain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1% in 114 h, It is suggested that multi-species bacteria be used as functional bacteria in biorernediation ofmariculture environment.

  3. 纤维素降解菌株的筛选及其产酶条件优化%Studies on Screening of Methane Fermentation Cellulose degrading Bacteria and its Optimization of Culture Conditions

    Institute of Scientific and Technical Information of China (English)

    高星爱; 黄枭; 张永锋; 赵新颖; 程孟秋; 刘鹏; 刘思言

    2012-01-01

    为了寻求快速有效降解沼气发酵有机质中的高分子化合物,本实验从腐殖质土壤中筛选到一株高效降解纤维素菌株,在以羧甲基纤维素钠为唯一碳源的液体培养基中培养,所产生的纤维素酶对玉米芯和滤纸均表现出较强降解能力.其次做了对菌株培养条件优化的实验,结果表明,菌株的最佳降解纤维素条件为反应温度30℃、发酵液接种量为1%、0.75%羧甲基纤维素钠为碳源、1.5%胰蛋白胨为氮源,优化菌株培养条件后,纤维素酶活力增加了2.8倍.%In order to be effective, rapid degradation of organic polymer compound biogas fermentation, from soil degradation to a plant screening high efficiency degradation cellulose strain. In sodium carboxyl methyl cellulose as the only carbon source of liquid medium training strains, the cellulose enzyme produced for several and filter paper are show have better degradation ability. Next to the optimization of the strains of the culture condition experiment results show that the best cellulolytic strains of the conditions for the reaction temperature 30°C, fermented liquid 1% inoculated quantity, carbon source sodium carboxyl methyl cellulose 0.75%, had 1.5% nitrogen pancreatic specially designed, and so on. Optimization strains after the culture condition, cellulose enzyme activity has increased 2.8times.

  4. SU-8 process optimization for high fiber coupling efficiency of liquid crystal filled photonic bandgap fiber components

    DEFF Research Database (Denmark)

    Wei, Lei; Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard

    2009-01-01

    SU-8 structures are built up to increase the fiber coupling efficiency of liquid crystal photonic bandgap fiber components. The resolution reduction of UV exposure is minimized to 4%, and insertion loss is reduced to 2.7dB.......SU-8 structures are built up to increase the fiber coupling efficiency of liquid crystal photonic bandgap fiber components. The resolution reduction of UV exposure is minimized to 4%, and insertion loss is reduced to 2.7dB....

  5. Optimization of culture media for large-scale lutein production by heterotrophic Chlorella vulgaris.

    Science.gov (United States)

    Jeon, Jin Young; Kwon, Ji-Sue; Kang, Soon Tae; Kim, Bo-Ra; Jung, Yuchul; Han, Jae Gap; Park, Joon Hyun; Hwang, Jae Kwan

    2014-01-01

    Lutein is a carotenoid with a purported role in protecting eyes from oxidative stress, particularly the high-energy photons of blue light. Statistical optimization was performed to growth media that supports a higher production of lutein by heterotrophically cultivated Chlorella vulgaris. The effect of media composition of C. vulgaris on lutein was examined using fractional factorial design (FFD) and central composite design (CCD). The results indicated that the presence of magnesium sulfate, EDTA-2Na, and trace metal solution significantly affected lutein production. The optimum concentrations for lutein production were found to be 0.34 g/L, 0.06 g/L, and 0.4 mL/L for MgSO4 ·7H2 O, EDTA-2Na, and trace metal solution, respectively. These values were validated using a 5-L jar fermenter. Lutein concentration was increased by almost 80% (139.64 ± 12.88 mg/L to 252.75 ± 12.92 mg/L) after 4 days. Moreover, the lutein concentration was not reduced as the cultivation was scaled up to 25,000 L (260.55 ± 3.23 mg/L) and 240,000 L (263.13 ± 2.72 mg/L). These observations suggest C. vulgaris as a potential lutein source.

  6. Optimization of a Culture Medium for Increased Mevinolin Production by Aspergillus terreus Strain

    Directory of Open Access Journals (Sweden)

    Atalla, M. M.

    2008-01-01

    Full Text Available Fungi are important sources for the production of some pharmaceutical compounds. e.g. lovastatin, mevinolin and monacolin K. These are competitive inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, the rate limiting enzyme of cholesterol synthesis pathway. Four fungal strains of Aspergillus terreus and one Penicillium patulum were tested for their potential to produce mevinolin. The fungal strains were cultivated in four different semi-synthetic media to select a fermentation medium and a fungal strain that has the ability to secret mevinolin in high yield. The fermentation followed by TLC screening. Positive results were evaluated by confirmatory HPLC. A. terreus J9 was the best strain for producing mevinolin with a level of 148.66 mg/L of Dox-rice medium. Cultivation a 7.5 L in fermenter, A. terreus J9 produced 932.15 mg/L after 96 h using Dox-rice medium at 6.5 pH. Rise in acidity or alkalinity decrease mevinolin producing ability. Ammonium sulphate in the medium as sulphur and nitrogen sources influenced greatly mevinolin production as well as incubation period. Maximum production was obtained after 36 h incubation. The maximum value of the mevinolin concentratiom (1761.6 mg/L was attained at 400rpm after 60 h fermentation at 28 ºC. The optimized medium resulted in a significant increase of mevinolin cocentration, as compared with that obtained by the fermentation of many other A. terreus species.

  7. Optimization of cultural conditions for protease production by a fungal species

    Directory of Open Access Journals (Sweden)

    Kamath P

    2010-01-01

    Full Text Available Studies were carried out on a paddy soil fungal isolate identified to be a strain of Aspergillus niger from Manipal. The parameters that largely impact enzyme production viz., fermentation time, impeller speed, pH, temperature and nutrient supplements were studied. Optimization of production parameters for production of protease was done by the single-parameter mode. Casein served as substrate and proteolytic activity was estimated using Folin-Ciocalteau method at 660 nm. A maximum yield of 71.3 mg tyrosine/g casein substrate was produced in 96 h on a soluble starch medium at pH 4 in shake flask experiments. Production was carried out on a 3-liter fermenter and 40.7 mg of tyrosine was liberated/g of substrate. The enzyme was extracted with 50% ammonium sulfate and sodium dodecyl sulfate-Polyacrylamide gel electrophoresis showed two bands having mw 45.7 kDa and 38.5 kDa, respectively. The enzyme activity was found to be 147.84 U/ml.

  8. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    Science.gov (United States)

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body.

  9. Cultural Characteristics of Shimizuomyces paradoxus Collected from Korea

    OpenAIRE

    2010-01-01

    This study investigated the cultural characteristics of Shimizuomyces paradoxus in different nutritional and environmental conditions. The highest mycelial growth was observed in Schizophyllum (mushroom) genetics complete medium plus yeast extract agar medium, and the optimal temperature and pH were 25℃ and pH 8.0, respectively. The optimal carbon and nitrogen sources were 1% dextrose and 1% peptone in agar. However, in liquid culture the highest dry mycelium weight was found for the potato d...

  10. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses.

    Science.gov (United States)

    Foan, L; Simon, V

    2012-09-21

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the optimal PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The optimal analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability.

  11. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Afraz, Ahmadreza [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Rafati, Amir Abbas, E-mail: aa_rafati@basu.ac.ir [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Najafi, Mojgan [Department of Materials Engineering, Hamedan University of Technology (HUT), 65169 Hamedan (Iran, Islamic Republic of)

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. - Highlights: • New method for simultaneous determination of AA, DA and UA was developed. • MWCNT/ionic liquid/cauliflower-like Au nanostructure was used for CPE modification. • Optimization of electrode composition was done by Design-Expert software. • The pH effect, peak separation mechanism and real samples was thoroughly studied.

  12. Optimization of culture conditions for maintaining porcine induced pluripotent stem cells.

    Science.gov (United States)

    Gao, Yi; Guo, Yanjie; Duan, Anqin; Cheng, De; Zhang, Shiqiang; Wang, Huayan

    2014-01-01

    Ground state porcine induced pluripotent stem cells (piPSCs), which retain the potential to generate chimeric animal and germline transmission, are difficult to produce. This study investigated morphological and biological progression at the early stage of porcine somatic cell reprogramming, and explored suitable conditions to increase the induction efficiency of piPSCs. A cocktail of defined transcription factors was used to generate piPSCs. The amphotropic retrovirus, which carried human OCT4 (O), SOX2 (S), KLF4 (K), C-MYC (M), TERT (T), and GFP, were used to infect porcine embryonic fibroblasts (PEFs). The number of clones derived from OSKM (4F) and OSKMT (4F+T) was significantly higher than that from SKM (3F) and SKMT (3F+T), suggesting that OCT4 played a critical role in regulating porcine cell reprogramming. The number of alkaline phosphatase-positive clones from a medium with leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) (M1 medium) was significantly higher than that with insulin and 2i PD0325901/CHIR99021 (M2 medium), indicating that insulin and 2i could not effectively maintain piPSC propagation. In the M1 medium, piPSC lines could not maintain the typical self-renewal morphology on gelatin-coated and Matrigel-coated plates. Without the mouse embryonic fibroblast (MEF) feeder, piPSCs started to simultaneously differentiate. Based on the potential for self-renewal and activation of pluripotent markers, we found that the culture condition of 4F+T plus LIF and bFGF plus MEF feeder promoted PEF reprogramming more efficiently than the other conditions tested here. Two piPSC lines (IB-1 and IB-2) were derived and maintained for up to 20 passages in vitro.

  13. Monoxenic liquid culture with Escherichia coli of the free-living nematode Panagrolaimus sp. (strain NFS 24-5), a potential live food candidate for marine fish and shrimp larvae.

    Science.gov (United States)

    Ayub, Farhana; Seychelles, Laurent; Strauch, Olaf; Wittke, Martina; Ehlers, Ralf-Udo

    2013-09-01

    The free-living, bacterial-feeding nematode Panagrolaimus sp. (strain NFS 24-5) has potential for use as live food for marine shrimp and fish larvae. Mass production in liquid culture is a prerequisite for its commercial exploitation. Panagrolaimus sp. was propagated in monoxenic liquid culture on Escherichia coli and parameters, like nematode density, population dynamics and biomass were recorded and compared with life history table data. A mean maximum nematode density of 174,278 mL(-1) and a maximum of 251,000 mL(-1) were recorded on day 17 after inoculation. Highest average biomass was 40 g L(-1) at day 13. The comparison with life history table data indicated that the hypothetical potential of liquid culture is much higher than documented during this investigation. Nematode development is delayed in liquid culture and egg production per female is more than five times lower than reported from life history trait analysis. The latter assessed a nematode generation time of 7.1 days, whereas the process time at maximum nematode density in liquid culture was 16 days indicating that a reduction of the process time can be achieved by further investigating the influence of nematode inoculum density on population development. The results challenge future research to reduce process time and variability and improve population dynamics also during scale-up of the liquid culture process.

  14. Development of a fast extraction method and optimization of liquid chromatography-mass spectrometry for the analysis of phenolic compounds in lentil seed coats.

    Science.gov (United States)

    Mirali, Mahla; Ambrose, Stephen J; Wood, Stephen A; Vandenberg, Albert; Purves, Randy W

    2014-10-15

    A systematic set of optimization experiments was conducted to design an efficient extraction and analysis protocol for screening six different sub-classes of phenolic compounds in the seed coat of various lentil (Lens culinaris Medik.) genotypes. Different compounds from anthocyanidins, flavan-3-ols, proanthocyanidins, flavanones, flavones, and flavonols sub-classes were first optimized for use as standards for liquid chromatography mass spectrometry (LC-MS) with UV detection. The effect of maceration duration, reconstitution solvent, and extraction solvent were investigated using lentil genotype CDC Maxim. Chromatographic conditions were optimized by examining column separation efficiencies, organic composition, and solvent gradient. The results showed that a 1h maceration step was sufficient and that non-acidified solvents were more appropriate; a 70:30 acetone: water (v/v) solvent was ultimately selected. Using a Kinetex PFP column, the organic concentration, gradient, and flow rate were optimized to maximize the resolution of phenolic compounds in a short 30-min analysis time. The optimized method was applied to three lentil genotypes with different phenolic compound profiles to provide information of value to breeding programs.

  15. Optimization of cultural conditions for biosurfactant production by Pleurotus djamor in solid state fermentation.

    Science.gov (United States)

    Velioglu, Zulfiye; Ozturk Urek, Raziye

    2015-11-01

    Being eco-friendly, less toxic, more biodegradable and biocompatible, biological surfactants have higher activity and stability compared to synthetic ones. In spite of the fact that there are abundant benefits of biosurfactants over the synthetic congeners, the problem related with the economical and large scale production proceeds. The utilization of several industrial wastes in the production media as substrates reduces the production cost. This current study aims optimization of biosurfactant production conditions by Pleurotus djamor, grown on sunflower seed shell, grape wastes or potato peels as renewable cheap substrates in solid state fermentation. After determination of the best substrate for biosurfactant production, we indicate optimum size and amount of solid substrate, volume of medium, temperature, pH and Fe(2+) concentrations on biosurfactant production. In optimum conditions, by reducing water surface tension to 28.82 ± 0.3 mN/m and having oil displacement diameter of 3.9 ± 0.3 cm, 10.205 ± 0.5 g/l biosurfactant was produced. Moreover, chemical composition of biosurfactant produced in optimum condition was determined by FTIR. Lastly, laboratory's large-scale production was carried out in optimum conditions in a tray bioreactor designed by us and 8.9 ± 0.5 g/l biosurfactant was produced with a significant surface activity (37.74 ± 0.3 mN/m). With its economical suggestions and applicability of laboratory's large-scale production, this work indicates the possibility of using low cost agro-industrial wastes as renewable substrates for biosurfactant production. Therefore, using economically produced biosurfactant will reduce cost in several applications such as bioremediation, oil recovery and biodegradation of toxic chemicals.

  16. Screening and optimization of low-cost medium for Pseudomonas putida Rs-198 culture using RSM.

    Science.gov (United States)

    Peng, Yanjie; He, Yanhui; Wu, Zhansheng; Lu, Jianjiang; Li, Chun

    2014-01-01

    The plant growth-promoting rhizobacterial strain Pseudomonas putida Rs-198 was isolated from salinized soils from Xinjiang Province. We optimized the composition of the low-cost medium of P. putida Rs-198 based on its bacterial concentration, as well as its phosphate-dissolving and indole acetic acid (IAA)-producing capabilities using the response surface methodology (RSM), and a mathematical model was developed to show the effect of each medium component and its interactions on phosphate dissolution and IAA production. The model predicted a maximum phosphate concentration in medium containing 63.23 mg/L inorganic phosphate with 49.22 g/L corn flour, 14.63 g/L soybean meal, 2.03 g/L K₂HPO₄, 0.19 g/L MnSO₄ and 5.00 g/L NaCl. The maximum IAA concentration (18.73 mg/L) was predicted in medium containing 52.41 g/L corn flour, 15.82 g/L soybean meal, 2.40 g/L K₂HPO₄, 0.17 g/L MnSO₄ and 5.00 g/L NaCl. These predicted values were also verified through experiments, with a cell density of 10(13) cfu/mL, phosphate dissolution of 64.33 mg/L, and IAA concentration of 18.08 mg/L. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The study aims to provide a basis for industrialized fermentation using P. putida Rs-198.

  17. Screening and optimization of low-cost medium for Pseudomonas putida Rs-198 culture using RSM

    Directory of Open Access Journals (Sweden)

    Yanjie Peng

    2014-12-01

    Full Text Available The plant growth-promoting rhizobacterial strain Pseudomonas putida Rs-198 was isolated from salinized soils from Xinjiang Province. We optimized the composition of the low-cost medium of P. putida Rs-198 based on its bacterial concentration, as well as its phosphate-dissolving and indole acetic acid (IAA-producing capabilities using the response surface methodology (RSM, and a mathematical model was developed to show the effect of each medium component and its interactions on phosphate dissolution and IAA production. The model predicted a maximum phosphate concentration in medium containing 63.23 mg/L inorganic phosphate with 49.22 g/L corn flour, 14.63 g/L soybean meal, 2.03 g/L K2HPO4, 0.19 g/L MnSO4 and 5.00 g/L NaCl. The maximum IAA concentration (18.73 mg/L was predicted in medium containing 52.41 g/L corn flour, 15.82 g/L soybean meal, 2.40 g/L K2HPO4, 0.17 g/L MnSO4 and 5.00 g/L NaCl. These predicted values were also verified through experiments, with a cell density of 10(13 cfu/mL, phosphate dissolution of 64.33 mg/L, and IAA concentration of 18.08 mg/L. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The study aims to provide a basis for industrialized fermentation using P. putida Rs-198.

  18. Evaluation of three real-time PCR assays for differential identification of Mycobacterium tuberculosis complex and nontuberculous mycobacteria species in liquid culture media.

    Science.gov (United States)

    Jung, Yu Jung; Kim, Ji-Youn; Song, Dong Joon; Koh, Won-Jung; Huh, Hee Jae; Ki, Chang-Seok; Lee, Nam Yong

    2016-06-01

    We evaluated the analytical performance of M. tuberculosis complex (MTBC)/nontuberculous mycobacteria (NTM) PCR assays for differential identification of MTBC and NTM using culture-positive liquid media. Eighty-five type strains and 100 consecutive mycobacterial liquid media cultures (MGIT 960 system) were analyzed by a conventional PCR assay (MTB-ID(®) V3) and three real-time PCR assays (AdvanSure™ TB/NTM real-time PCR, AdvanSure; GENEDIA(®) MTB/NTM Detection Kit, Genedia; Real-Q MTB & NTM kit, Real-Q). The accuracy rates for reference strains were 89.4%, 100%, 98.8%, and 98.8% for the MTB-ID V3, AdvanSure, Genedia, and Real-Q assays, respectively. Cross-reactivity in the MTB-ID V3 assay was mainly attributable to non-mycobacterium Corynebacterineae species. The diagnostic performance was determined using clinical isolates grown in liquid media, and the overall sensitivities for all PCR assays were higher than 95%. In conclusion, the three real-time PCR assays showed better performance in discriminating mycobacterium species and non-mycobacterium Corynebacterineae species than the conventional PCR assay.

  19. 正交设计法筛选槐耳菌丝体液体培养基的研究%Selection on liquid culture medium for mycelium of Trametes robiniophila Nurr. by orthogonal design

    Institute of Scientific and Technical Information of China (English)

    杨子美; 郭成金

    2009-01-01

    以槐耳茵丝体生物量为主要指标,采用不同碳源和氮源进行单因素初选试验,然后以不同比例的混合碳氪源进行正交试验.结果表明,槐耳茵丝体液体最佳培养基是玉米渣200 g/L,蔗糖20 g/L,酵母膏3 g/L,麦麸3.5 g/L,KH2PO42.0 g/L,MgSO4·7H2 1.0 g/L和VB1 6 mg/L,温度28℃,pH自然.其茵丝体生物量得率为21.6 g/L.%Biomass of mycelium in liquid culture medium for Trametes robiniophila Mutt. as major index, firstly different carbon source and nitrogen source were adopted to early out the single factor primary election in the experiment, carrying out tests again for different proportional commixture of carbon source and nitrogen source. The results showed that the op-timal medium was leaching solution of com 200 g/L, cane sugar 20 g/L, yeast extract 3 g/L, wheat bran 3. 5 g/L,KH2PO4 2. 0 g/L, MgSO4· 7H2 O 1.0 g/L, VB1 6 mg/L with 28 ℃, natural pH. The production rate of biomass on mycelium of Trarnetes robiniophila Murr. reached 21.6 g/L in the liquid culture medium.

  20. Optimization of solid phase extraction clean up and validation of quantitative determination of corticosteroids in urine by liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens Hinge; Hansen, Lene Gram; Pedersen, Mikael

    2008-01-01

    A solid phase extraction (SPE) method for extraction and clean up of 9 synthetic corticosteroids was optimized for quantification by reversed-phase high-performance liquid chromatography/negative electrospray ionisation mass spectrometry. Clean up was accomplished using a mixed mode polymeric...... strong anion exchange SPE column. The final method was validated according to EU regulations for determination of residues of veterinarian drugs in products of animal origin. Initial results showed a large difference in ion suppression between samples of porcine and bovine urine. The aim of optimisation...

  1. Optimization of HEK-293S cell cultures for the production of adenoviral vectors in bioreactors using on-line OUR measurements.

    Science.gov (United States)

    Gálvez, J; Lecina, M; Solà, C; Cairó, J J; Gòdia, F

    2012-01-01

    The culture of HEK-293S cells in a stirred tank bioreactor for adenoviral vectors production for gene therapy is studied. Process monitoring using oxygen uptake rate (OUR) was performed. The OUR was determined on-line by the dynamic method, providing good information of the process evolution. OUR enabled cell activity monitoring, facilitating as well the determination of the feeding rate in perfusion cultures and when to infect the culture. Batch cultures were used to validate the monitoring methodology. A cell density of 10×10(5)cell/mL was infected, producing 1.3×10(9) infectious viral particles/mL (IVP/mL). To increase cell density values maintaining cell specific productivity, perfusion cultures, based on tangential flow filtration, were studied. In this case, OUR measurements were used to optimize the dynamic culture medium feeding strategy, addressed to avoid any potential nutrient limitation. Furthermore, the infection protocol was defined in order to optimize the use of the viral inoculum, minimizing the uncontrolled release of particles through the filter unit mesh. All these developments enabled an infection at 78×10(5)cell/mL with the consequent production of 44×10(9)IVP/mL, representing a cell specific productivity 4.3 times higher than for the batch culture.

  2. Reliability-Based and Cost-Oriented Product Optimization Integrating Fuzzy Reasoning Petri Nets, Interval Expert Evaluation and Cultural-Based DMOPSO Using Crowding Distance Sorting

    Directory of Open Access Journals (Sweden)

    Zhaoxi Hong

    2017-08-01

    Full Text Available In reliability-based and cost-oriented product optimization, the target product reliability is apportioned to subsystems or components to achieve the maximum reliability and minimum cost. Main challenges to conducting such optimization design lie in how to simultaneously consider subsystem division, uncertain evaluation provided by experts for essential factors, and dynamic propagation of product failure. To overcome these problems, a reliability-based and cost-oriented product optimization method integrating fuzzy reasoning Petri net (FRPN, interval expert evaluation and cultural-based dynamic multi-objective particle swarm optimization (DMOPSO using crowding distance sorting is proposed in this paper. Subsystem division is performed based on failure decoupling, and then subsystem weights are calculated with FRPN reflecting dynamic and uncertain failure propagation, as well as interval expert evaluation considering six essential factors. A mathematical model of reliability-based and cost-oriented product optimization is established, and the cultural-based DMOPSO with crowding distance sorting is utilized to obtain the optimized design scheme. The efficiency and effectiveness of the proposed method are demonstrated by the numerical example of the optimization design for a computer numerically controlled (CNC machine tool.

  3. Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

    DEFF Research Database (Denmark)

    Tveitaskog, Kari Anne; Haglind, Fredrik

    2012-01-01

    This paper is aimed at designing and optimizing combined cycles for marine applications. For this purpose, an in-house numerical simulation tool called DNA (Dynamic Network Analysis) and a genetic algorithm-based optimization routine are used. The top cycle is modeled as the aero-derivative gas...

  4. 大黄通气口服液的提取纯化工艺优选%Optimization of Extraction and Purification Technology for Dahuang Tongqi Oral Liquid

    Institute of Scientific and Technical Information of China (English)

    刘光斌; 谢六生; 隆旭红; 李怀彪

    2012-01-01

    Objective: To optimize extraction and purification technology for Dahuang Tongqi oral liquid. Method; With volume of volatile oil as index, orthogonal test was used to optimize extraction technology of volatile oil from Aucklandia lappa, Citrus sinensis and so on with soaking time, extraction times, the amount of water as factors; With yield of water extract, total content of rhein, emodin and chrysophanol as indexes, orthogonal test was used to investigate factors of water extraction process for Dahuang Tongqi oral liquid, such as extraction time, extraction times and the amount of water; With yield of dry extract, total extraction ratio of rhein, emodin and chrysophanol as indexes, orthogonal test was used to investigate factors of ethanol precipitation process for Dahuang Tongqi oral liquid, such as relative density of liquid, the concentration of ethanol and alcohol precipitation time. Result; Optimized extraction technology of volatile oil was; distilling 2 h with 4 times the amount of water; optimum water extraction technology was; boiling 2 h with 8 times the amount of water, 2 h per time; optimized alcohol precipitation process was; concetrated to relative density of 1.20 (80 °C) , 95% ethanol was added to liquid contained ethanol of 50% , alcohol precipitation time 24 h. Conclusion: Optimized extraction and purification technology for Dahuang Tongqi oral liquid was reasonable and feasible, it was suitable for requirements of industrial production.%目的:优选大黄通气口服液的提取纯化工艺.方法:以挥发油提出量为指标,对木香、枳实等药材中挥发油提取工艺进行正交试验优化,考察因素为加水量、浸泡时间及提取时间;以水提取物得率和大黄酸、大黄素、大黄酚总量为考察指标,采用正交设计法考察煮提时间、煮提次数和加水量等因素对大黄通气口服液水提取工艺的影响;以干浸膏得率与大黄酸、大黄素、大黄酚总提取率为考察指标,

  5. The role of goal representations, cultural identity, and dispositional optimism in the depressive experiences of American Indian youth from a Northern Plains tribe.

    Science.gov (United States)

    Tyser, Jason; Scott, Walter D; Readdy, Tucker; McCrea, Sean M

    2014-03-01

    American Indian researchers and scholars have emphasized the importance of identifying variables that promote resilience and protect against the development of psychopathology in American Indian youth. The present study examined the role of self-regulation, specifically goal characteristics (i.e., goal self-efficacy, goal specificity, intrinsic vs. extrinsic motivation, and goal conflict) and dispositional optimism, as well as cultural identity and self-reported academic grades in the depressive experiences of American Indian youth from a North American plains tribe. One hundred and sixty-four participants (53% female) completed measures of goal representations, cultural identity, dispositional optimism, academic performance, and depressive symptoms. Results supported a model in which higher goal self-efficacy, American Indian cultural identity, grade point average, and dispositional optimism each significantly predicted fewer depressive symptoms. Moreover, grade point average and goal self-efficacy had both direct and indirect (through dispositional optimism) relationships with depressive symptoms. Our findings underscore the importance of cognitive self-regulatory processes and cultural identity in the depressive experiences for these American Indian youth and may have implications for youth interventions attempting to increase resiliency and decrease risk for depressive symptoms.

  6. Self-Regulation among Youth in Four Western Cultures: Is There an Adolescence-Specific Structure of the Selection-Optimization-Compensation (SOC) Model?

    Science.gov (United States)

    Gestsdottir, Steinunn; Geldhof, G. John; Paus, Tomáš; Freund, Alexandra M.; Adalbjarnardottir, Sigrun; Lerner, Jacqueline V.; Lerner, Richard M.

    2015-01-01

    We address how to conceptualize and measure intentional self-regulation (ISR) among adolescents from four cultures by assessing whether ISR (conceptualized by the SOC model of Selection, Optimization, and Compensation) is represented by three factors (as with adult samples) or as one "adolescence-specific" factor. A total of 4,057 14-…

  7. Statistical optimization of influenza H1N1 production from batch cultures of suspension Vero cells (sVero).

    Science.gov (United States)

    Paillet, Cristian; Forno, Guillermina; Soldano, Nicolas; Kratje, Ricardo; Etcheverrigaray, Marina

    2011-09-22

    Efficient vaccine production requires the growth of large quantities of virus produced with high yield from a safe host system. Human influenza vaccines are produced in embryonated chicken eggs. However, over the last decade many efforts have allowed the establishment of cell culture-derived vaccines. We generated a Vero cell line adapted to grow in suspension (sVero) in a serum-free medium and evaluated it for its potential as host cell for influenza vaccine production. Initially we studied the capacity of sVero cells to grow in the presence of incremental concentrations of trypsin. In comparison with adherent Vero cells (aVero), we found that sVero cells maintain their growth kinetics even with a three-fold increase in trypsin concentration. The influence of the conditions of infection on the yield of H1N1 produced in serum-free suspension cultures of sVero cells was investigated by a 2(2) full factorial experiment with center point. Each experiment tested the influence of the multiplicity of infection (m.o.i.) and trypsin concentration, on production yields at two levels, in four possible combinations of levels and conditions, plus a further combination in which each condition was set in the middle of its extreme levels. On the basis of software analysis, a combination of m.o.i. of 0.0066TCID(50%)/cell and trypsin concentration of 5μg/1.0×10(6) cells with a desirability of 0.737 was selected as the optimized condition for H1N1 production in sVero cells. Our results show the importance of proper selection of infection conditions for H1N1 production on sVero cells in serum-free medium. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. A time-to-event pharmacodynamic model describing treatment response in patients with pulmonary tuberculosis using days to positivity in automated liquid mycobacterial culture.

    Science.gov (United States)

    Chigutsa, Emmanuel; Patel, Kashyap; Denti, Paolo; Visser, Marianne; Maartens, Gary; Kirkpatrick, Carl M J; McIlleron, Helen; Karlsson, Mats O

    2013-02-01

    Days to positivity in automated liquid mycobacterial culture have been shown to correlate with mycobacterial load and have been proposed as a useful biomarker for treatment responses in tuberculosis. However, there is currently no quantitative method or model to analyze the change in days to positivity with time on treatment. The objectives of this study were to describe the decline in numbers of mycobacteria in sputum collected once weekly for 8 weeks from patients on treatment for tuberculosis using days to positivity in liquid culture. One hundred forty-four patients with smear-positive pulmonary tuberculosis were recruited from a tuberculosis clinic in Cape Town, South Africa. A nonlinear mixed-effects repeated-time-to-event modeling approach was used to analyze the time-to-positivity data. A biexponential model described the decline in the estimated number of bacteria in patients' sputum samples, while a logistic model with a lag time described the growth of the bacteria in liquid culture. At baseline, the estimated number of rapidly killed bacteria is typically 41 times higher than that of those that are killed slowly. The time to kill half of the rapidly killed bacteria was about 1.8 days, while it was 39 days for slowly killed bacteria. Patients with lung cavitation had higher bacterial loads than patients without lung cavitation. The model successfully described the increase in days to positivity as treatment progressed, differentiating between bacteria that are killed rapidly and those that are killed slowly. Our model can be used to analyze similar data from studies testing new drug regimens.

  9. Optimized simultaneous saccharification and co-fermentation of rice straw for ethanol production by Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture using design of experiments.

    Science.gov (United States)

    Suriyachai, Nopparat; Weerasaia, Khatiya; Laosiripojana, Navadol; Champreda, Verawat; Unrean, Pornkamol

    2013-08-01

    Herein an ethanol production process from rice straw was optimized. Simultaneous saccharification and co-fermentation (SSCF) using Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture was carried out to enhance ethanol production. The optimal saccharification solid loading was 5%. Key fermentation parameters for co-culture including cell ratio, agitation rate and temperature was rationally optimized using design of experiment (DoE). Optimized co-culture conditions for maximum ethanol production efficiency were at S. cerevisiae:S. stipitis cell ratio of 0.31, agitation rate of 116 rpm and temperature of 33.1°C. The optimized SSCF process reached ethanol titer of 15.2g/L and ethanol yield of 99% of theoretical yield, consistent with the DoE model prediction. Moreover, SSCF process under high biomass concentration resulted in high ethanol concentration of 28.6g/L. This work suggests the efficiency and scalability of the developed SSCF process which could provide an important basis for the economic feasibility of ethanol production from lignocelluloses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Adjoint-based shape optimization of fin geometry for enhanced solid/liquid phase-change process

    Science.gov (United States)

    Morimoto, Kenichi; Suzuki, Yuji

    2015-11-01

    In recent years, the control of heat transfer processes, which play a critical role in various engineering devices/systems, has gained renewed attention. The present study aims to establish an adjoint-based shape optimization method for high-performance heat transfer processes involving phase-change phenomena. A possible example includes the application to the thermal management technique using phase-change material. Adjoint-based shape optimization scheme is useful to optimal shape design and optimal control of systems, for which the base function of the solution is unknown and the solution includes an infinite number of degrees of freedom. Here we formulate the shape-optimization scheme based on adjoint heat conduction analyses, focusing on the shape optimization of fin geometry. In the computation of the developed scheme, a meshless local Petrov-Galerkin (MLPG) method that is suited for dealing with complex boundary geometry is employed, and the enthalpy method is adopted for analyzing the motion of the phase-change interface. We examine in detail the effect of the initial geometry and the node distribution in the MLPG analysis upon the final solution of the shape optimization. Also, we present a new strategy for the computation using bubble mesh.

  11. Theoretical searches and spectral computations of preferred conformations of various absolute configurations for a cyclodipeptide, cordycedipeptide A from the culture liquid of Cordyceps sinensis

    Science.gov (United States)

    Mang, Chao-Yong; Liu, Cai-Ping; Liu, Guang-Ming; Jiang, Bei; Lan, Hai; Wu, Ke-Chen; Yan, Ya; Li, Hai-Fei; Yang, Ming-Hui; Zhao, Yu

    2015-02-01

    A cyclic dipeptide often has the multiple configurations and the abundant conformations. The density functional theory (DFT) method is used to search the preferred conformation of the most probable configuration for cordycedipeptide A isolated from the culture liquid of Cordyceps sinensis. The time-dependent DFT approach is exploited to describe the profile of electronic circular dichroism (CD). The calculated results show that the most probable configuration is 3S6R7S, whose preferred conformation has a negative optical rotation and a positive lowest energy electronic CD band.

  12. Optimization of Liquid-Sol id State Fermentation of Vinegar%前液后固制醋发酵条件的优化研究

    Institute of Scientific and Technical Information of China (English)

    魏如腾; 侯红萍

    2015-01-01

    在前液后固制醋的基础上,通过正交试验对酒精发酵和醋酸发酵的条件进行优化。结果表明:酒精发酵的最优条件为接种量0.8‰ ADY+0.4%糖化酶、料水比1∶2、发酵时间7天。醋酸发酵的最优条件为发酵温度32℃、酒精度9%、接种量7%。在优化条件下,发酵时间缩短,产酸速度提高。%On the basis of liquid-solid state fermentation of vinegar, the conditions of alcohol fermentation and acetic acid fermentation are optimized by orthogonal test.The results show that the optimal conditions for alcohol fermentation are as follows:the inoculation amount of 0.8‰ ADY+0.4% saccharifying enzyme,the ratio of material to water of 1 ∶ 2,and the fermentation time of 7 days.The optimal conditions for acetic acid fermentation are as follows: the fermentation temperature of 32 ℃,the alcohol degree of 9%,and the inoculation amount of 7%.Under the optimal conditions,the fermentation time shortens and the acid-producing speed increases.

  13. Development of response surface methodology for optimization of extraction parameters and quantitative estimation of embelin from Embelia ribes Burm by high performance liquid chromatography

    Science.gov (United States)

    Alam, Md. Shamsir; Damanhouri, Zoheir A.; Ahmad, Aftab; Abidin, Lubna; Amir, Mohd; Aqil, Mohd; Khan, Shah Alam; Mujeeb, Mohd

    2015-01-01

    Background: Embelia ribes Burm is widely used medicinal plant for the treatment of different types of disorders in the Indian traditional systems of medicine. Objective: The present work was aimed to optimize the extraction parameters of embelin from E. ribes fruits and also to quantify embelin content in different extracts of the plant. Materials and Methods: Optimization of extraction parameters such as solvent: drug ratio, temperature and time were carried out by response surface methodology (RSM). Quantitative estimation of embelin in different extracts of E. ribes fruits was done through high performance liquid chromatography. Results: The optimal conditions determined for extraction of embelin through RSM were; extraction time (27.50 min), extraction temperature 45°C and solvent: drug ratio (8:1). Under the optimized conditions, the embelin yield (32.71%) was equitable to the expected yield (31.07%, P > 0.05). These results showed that the developed model is satisfactory and suitable for the extraction process of embelin. The analysis of variance showed a high goodness of model fit and the accomplishment of the RSM method for improving embelin extraction from the fruits of E. ribes. Conclusion: It is concluded that this may be a useful method for the extraction and quantitative estimation of embelin from the fruits of E. ribes. PMID:26109763

  14. Optimization of a liquid chromatography ion mobility-mass spectrometry method for untargeted metabolomics using experimental design and multivariate data analysis.

    Science.gov (United States)

    Tebani, Abdellah; Schmitz-Afonso, Isabelle; Rutledge, Douglas N; Gonzalez, Bruno J; Bekri, Soumeya; Afonso, Carlos

    2016-03-24

    High-resolution mass spectrometry coupled with pattern recognition techniques is an established tool to perform comprehensive metabolite profiling of biological datasets. This paves the way for new, powerful and innovative diagnostic approaches in the post-genomic era and molecular medicine. However, interpreting untargeted metabolomic data requires robust, reproducible and reliable analytical methods to translate results into biologically relevant and actionable knowledge. The analyses of biological samples were developed based on ultra-high performance liquid chromatography (UHPLC) coupled to ion mobility - mass spectrometry (IM-MS). A strategy for optimizing the analytical conditions for untargeted UHPLC-IM-MS methods is proposed using an experimental design approach. Optimization experiments were conducted through a screening process designed to identify the factors that have significant effects on the selected responses (total number of peaks and number of reliable peaks). For this purpose, full and fractional factorial designs were used while partial least squares regression was used for experimental design modeling and optimization of parameter values. The total number of peaks yielded the best predictive model and is used for optimization of parameters setting.

  15. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid.

    Science.gov (United States)

    Afraz, Ahmadreza; Rafati, Amir Abbas; Najafi, Mojgan

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine.

  16. Development of response surface methodology for optimization of extraction parameters and quantitative estimation of embelin from Embelia ribes Burm by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Md. Shamsir Alam

    2015-01-01

    Full Text Available Background: Embelia ribes Burm is widely used medicinal plant for the treatment of different types of disorders in the Indian traditional systems of medicine. Objective: The present work was aimed to optimize the extraction parameters of embelin from E. ribes fruits and also to quantify embelin content in different extracts of the plant. Materials and Methods: Optimization of extraction parameters such as solvent: drug ratio, temperature and time were carried out by response surface methodology (RSM. Quantitative estimation of embelin in different extracts of E. ribes fruits was done through high performance liquid chromatography. Results: The optimal conditions determined for extraction of embelin through RSM were; extraction time (27.50 min, extraction temperature 45°C and solvent: drug ratio (8:1. Under the optimized conditions, the embelin yield (32.71% was equitable to the expected yield (31.07%, P > 0.05. These results showed that the developed model is satisfactory and suitable for the extraction process of embelin. The analysis of variance showed a high goodness of model fit and the accomplishment of the RSM method for improving embelin extraction from the fruits of E. ribes. Conclusion: It is concluded that this may be a useful method for the extraction and quantitative estimation of embelin from the fruits of E. ribes.

  17. Multiobjective optimization strategy based on desirability functions used for the microemulsion liquid chromatographic separation and quantification of norfloxacin and tinidazole in plasma and formulations.

    Science.gov (United States)

    Abou-Taleb, Noura Hemdan; El-Wasseef, Dalia Rashad; El-Sherbiny, Dina Tawfik; El-Ashry, Saadia Mohamed

    2015-03-01

    The aim of the present study was to optimize a microemulsion liquid chromatography method for the simultaneous determination of norfloxacin and tinidazole binary mixture using a chemometric protocol. Optimization experiments were conducted through a process of screening and optimization. A 2(7-4) fractional factorial design was used as screening design. While the location of optimum conditions was established by applying Derringer's desirability function. The optimal mobile phase composition was predicted to be: 3.5% w/v SDS, 10.03% v/v 1-propanol, 0.5% v/v 1-octanol, and 0.3% triethylamine in 0.02 M phosphoric acid at pH 6.5. The mobile phase was delivered isocratically at a flow rate of 1 mL/min with UV detection at 290 nm. Tinidazole and norfloxacin were eluted with retention times of 1.8 and 5.8 min, respectively. The calibration plots displayed good linear relationships in the concentration ranges of 0.5-50 and 0.75-75 μg/mL for norfloxacin and tinidazole, respectively. The method was successfully applied for determination of both drugs in pharmaceutical dosage forms and real human plasma. Where the accuracy was proved by the low values of % error and high values of recovery, also the relative standard deviation for the results did not exceed 1.5%, proving the precision of the method. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Commercial Refrigeration: Heat Transfer Optimization and Energy Reduction, Measurement and Verification of a Liquid Refrigerant Pump System Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gaul, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheppy, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-22

    This study describes the test results of a Refrigerant Pump System integrated into a commercial supermarket direct expansion (DX) vapor compression refrigeration system. The Liquid Refrigerant Pump System retrofit (patent-pending; application number 13/964,198) was introduced to NREL in August 2014 by CTA Architects Engineers.

  19. Managing liquidity

    DEFF Research Database (Denmark)

    Pokutta, Sebastian; Schmaltz, Christian

    2011-01-01

    Large banking groups face the question of how to optimally allocate and generate liquidity: in a central liquidity hub or in many decentralized branches. We translate this question into a facility location problem under uncertainty. We show that volatility is the key driver behind (de...... above which it is advantageous to open a liquidity center and show that it is a function of the volatility and the characteristic of the bank network. Finally, we discuss the n-branch model for real-world banking groups (10-60 branches) and show that it can be solved with high granularity (100 scenarios...

  20. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source.

    Science.gov (United States)

    Mauro, N A; Vogt, A J; Derendorf, K S; Johnson, M L; Rustan, G E; Quirinale, D G; Kreyssig, A; Lokshin, K A; Neuefeind, J C; An, Ke; Wang, Xun-Li; Goldman, A I; Egami, T; Kelton, K F

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg).

  1. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    Science.gov (United States)

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Rustan, G. E.; Quirinale, D. G.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; Wang, Xun-Li; Goldman, A. I.; Egami, T.; Kelton, K. F.

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (˜100 mg).

  2. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, N. A., E-mail: namauro@noctrl.edu [Department of Physics, North Central College, Naperville, Illinois 60540 (United States); Vogt, A. J. [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Derendorf, K. S. [Mechanical Engineering and Materials Science, Washington University, St. Louis, Missouri 63130 (United States); Johnson, M. L.; Kelton, K. F. [Department of Physics and Institute of Materials Science and Engineering, Washington University, 1 Brookings Drive, St. Louis, Missouri 63130 (United States); Rustan, G. E.; Quirinale, D. G.; Goldman, A. I. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Kreyssig, A. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Lokshin, K. A. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Neuefeind, J. C.; An, Ke [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wang, Xun-Li [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Ave., Kowloon (Hong Kong); Egami, T. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Physics and Astronomy, Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2016-01-15

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr{sub 64}Ni{sub 36} measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg)

  3. Systematic approach to optimize a pretreatment method for ultrasensitive liquid chromatography with tandem mass spectrometry analysis of multiple target compounds in biological samples.

    Science.gov (United States)

    Togashi, Kazutaka; Mutaguchi, Kuninori; Komuro, Setsuko; Kataoka, Makoto; Yamazaki, Hiroshi; Yamashita, Shinji

    2016-08-01

    In current approaches for new drug development, highly sensitive and robust analytical methods for the determination of test compounds in biological samples are essential. These analytical methods should be optimized for every target compound. However, for biological samples that contain multiple compounds as new drug candidates obtained by cassette dosing tests, it would be preferable to develop a single method that allows the determination of all compounds at once. This study aims to establish a systematic approach that enables a selection of the most appropriate pretreatment method for multiple target compounds without the use of their chemical information. We investigated the retention times of 27 known compounds under different mobile phase conditions and determined the required pretreatment of human plasma samples using several solid-phase and liquid-liquid extractions. From the relationship between retention time and recovery in a principal component analysis, appropriate pretreatments were categorized into several types. Based on the category, we have optimized a pretreatment method for the identification of three calcium channel blockers in human plasma. Plasma concentrations of these drugs in a cassette-dose clinical study at microdose level were successfully determined with a lower limit of quantitation of 0.2 pg/mL for diltiazem, 1 pg/mL for nicardipine, and 2 pg/mL for nifedipine.

  4. Cr(VI) transport via a supported ionic liquid membrane containing CYPHOS IL101 as carrier: system analysis and optimization through experimental design strategies.

    Science.gov (United States)

    Rodríguez de San Miguel, Eduardo; Vital, Xóchitl; de Gyves, Josefina

    2014-05-30

    Chromium(VI) transport through a supported liquid membrane (SLM) system containing the commercial ionic liquid CYPHOS IL101 as carrier was studied. A reducing stripping phase was used as a mean to increase recovery and to simultaneously transform Cr(VI) into a less toxic residue for disposal or reuse. General functions which describe the time-depending evolution of the metal fractions in the cell compartments were defined and used in data evaluation. An experimental design strategy, using factorial and central-composite design matrices, was applied to assess the influence of the extractant, NaOH and citrate concentrations in the different phases, while a desirability function scheme allowed the synchronized optimization of depletion and recovery of the analyte. The mechanism for chromium permeation was analyzed and discussed to contribute to the understanding of the transfer process. The influence of metal concentration was evaluated as well. The presence of different interfering ions (Ca(2+), Al(3+), NO3(-), SO4(2-), and Cl(-)) at several Cr(VI): interfering ion ratios was studied through the use of a Plackett and Burman experimental design matrix. Under optimized conditions 90% of recovery was obtained from a feed solution containing 7mgL(-1) of Cr(VI) in 0.01moldm(-3) HCl medium after 5h of pertraction.

  5. Impact of ultrasound on solid-liquid extraction of phenolic compounds from maritime pine sawdust waste. Kinetics, optimization and large scale experiments.

    Science.gov (United States)

    Meullemiestre, A; Petitcolas, E; Maache-Rezzoug, Z; Chemat, F; Rezzoug, S A

    2016-01-01

    Maritime pine sawdust, a by-product from industry of wood transformation, has been investigated as a potential source of polyphenols which were extracted by ultrasound-assisted maceration (UAM). UAM was optimized for enhancing extraction efficiency of polyphenols and reducing time-consuming. In a first time, a preliminary study was carried out to optimize the solid/liquid ratio (6g of dry material per mL) and the particle size (0.26 cm(2)) by conventional maceration (CVM). Under these conditions, the optimum conditions for polyphenols extraction by UAM, obtained by response surface methodology, were 0.67 W/cm(2) for the ultrasonic intensity (UI), 40°C for the processing temperature (T) and 43 min for the sonication time (t). UAM was compared with CVM, the results showed that the quantity of polyphenols was improved by 40% (342.4 and 233.5mg of catechin equivalent per 100g of dry basis, respectively for UAM and CVM). A multistage cross-current extraction procedure allowed evaluating the real impact of UAM on the solid-liquid extraction enhancement. The potential industrialization of this procedure was implemented through a transition from a lab sonicated reactor (3 L) to a large scale one with 30 L volume.

  6. A highly modular beamline electrostatic levitation facility, optimized for in situ high-energy x-ray scattering studies of equilibrium and supercooled liquids.

    Science.gov (United States)

    Mauro, N A; Kelton, K F

    2011-03-01

    High-energy x-ray diffraction studies of metallic liquids provide valuable information about structural evolution on the atomic length scale, leading to insights into the origin of the nucleation barrier and the processes of supercooling and glass formation. The containerless processing of the beamline electrostatic levitation (BESL) facility allows coordinated thermophysical and structural studies of equilibrium and supercooled liquids to be made in a contamination-free, high-vacuum (∼10(-8) Torr) environment. To date, the incorporation of electrostatic levitation facilities into synchrotron beamlines has been difficult due to the large footprint of the apparatus and the difficulties associated with its transportation and implementation. Here, we describe a modular levitation facility that is optimized for diffraction studies of high-temperature liquids at high-energy synchrotron beamlines. The modular approach used in the apparatus design allows it to be easily transported and quickly setup. Unlike most previous electrostatic levitation facilities, BESL can be operated by a single user instead of a user team.

  7. Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced.

    Science.gov (United States)

    Chauhan, A S; Srivastava, N; Kehri, H K; Sharma, B

    2013-01-01

    Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3), Trichoderma evansii (WF-3), Lasiodiplodia theobromae (WP-4) and Penicillium flavus (CL-4) based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v) by using galactose-containing polysaccharides like guar gum (GG), soya casein (SC) and wheat straw (WS). All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm) that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at -20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates.

  8. Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced

    Directory of Open Access Journals (Sweden)

    A. S. Chauhan

    2013-01-01

    Full Text Available Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3, Trichoderma evansii (WF-3, Lasiodiplodia theobromae (WP-4 and Penicillium flavus (CL-4 based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v by using galactose-containing polysaccharides like guar gum (GG, soya casein (SC and wheat straw (WS. All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at −20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates.

  9. Optimization of Cultural Conditions for Production of Extracellular Polymeric Substances (EPS by Serpentine Rhizobacterium Cupriavidus pauculus KPS 201

    Directory of Open Access Journals (Sweden)

    Arundhati Pal

    2013-01-01

    Full Text Available Extracellular polymeric substances (EPS are complex biopolymers produced by a wide array of microorganisms for protection against dessication, aggregation, adhesion, and expression of virulence. Growth associated production of EPS by Ni-resistant Cupriavidus pauculus KPS 201 was determined in batch culture using sodium gluconate as the sole carbon source. The optimum pH and temperature for EPS production were 6.5 and 25°C, respectively. Optimal EPS yield (118 μg/mL was attained at 0.35% Na-gluconate after 72 h of growth. Cupriavidus KPS 201 cells also utilized glutamate, acetate, pyruvate, fumarate, malate, malonate, formate, citrate, and succinate for EPS production. Although EPS production was positively influenced by the increase of nitrogen and phosphate in the growth medium, it was negatively influenced by nickel ions. Compositional analysis of the purified EPS showed that it is a homopolymer of rhamnose containing uronic acid, protein, and nucleic acid. Presence of lipids was also detected with spectroscopy. Non-destructive EPS mediated biofilm formation of KPS 201 was also visualized by epifluorescence microscopy.

  10. Enhanced Production of Botrallin and TMC-264 with in Situ Macroporous Resin Adsorption in Mycelial Liquid Culture of the Endophytic Fungus Hyalodendriella sp. Ponipodef12

    Directory of Open Access Journals (Sweden)

    Haiyu Luo

    2014-09-01

    Full Text Available Hyalodendriella sp. Ponipodef12, an endophytic fungus from the hybrid “Neva” of Populus deltoides × P. nigra, is a high producer of the bioactive dibenzo-α-pyrones botrallin and TMC-264. However, both the botrallin and TMC-264 produced by Hyalodendriella sp. Ponipodef12 were retained as both intracellular and extracellular products. The aim of this study was to evaluate an in situ macroporous resin adsorption for enhancement of botrallin and TMC-264 production in mycelial liquid culture of Hyalodendriella sp. Ponipodef12. Production of botrallin and TMC-264 was most effectively enhanced by macroporous resin DM-301 among the thirteen nonionic macroporous resins tested. The highest botrallin yield (51.47 mg/L, which was 2.29-fold higher than the control at 22.49 mg/L was obtained by adding resin DM-301 at 4.38% (g/mL to the culture broth on day 24 and allowing a period of 4 days for adsorption. The highest TMC-264 yield reached 47.74 mg/L, which was 11.76-fold higher than that of the control (4.06 mg/L, and was achieved by adding DM-301 resin at 4.38% (w/v in the culture broth on day 24 and allowing a period of 6 days for adsorption. The results show that in situ resin adsorption is an effective strategy for enhancing production of botrallin and TMC-264, and also for facilitating their recovery from mycelial liquid culture of Hyalodendriella sp. Ponipodef12.

  11. Study on liquidity-adjusted optimal trading strategy model%流动性调整的最优交易策略模型研究

    Institute of Scientific and Technical Information of China (English)

    林辉; 张涤新; 杨浩; 丁一

    2011-01-01

    通过放松理想化市场的假设条件,构建流动性调整的最优交易策略模型,并证明了交易策略在任意初始持仓、不同行情时的性质.研究表明在行情看涨时,若初始持仓过量则应采取"U型"卖出策略;若初始持仓适量,则应采取"递增型"卖出策略;若初始持仓为较少的多头或空头,则应采取先"递增型"买入,而后"递增型"卖出的策略;若逆市持有过量的空头,则应采取"递增型"买入策略.行情看跌情形则与看涨情形具有完全相反的结果.若行情看平,则应采取"递减型"卖出或"递增型"买入策略.本文最后分析了流动性对最优交易策略的影响.%By relaxing the hypothesis of Idealized Market, this paper presents the model of Liquidity-adjusted optimal trading strategy, and proves the characteristic about optimal tradingstrategies under the condition of different market and optional initial holding. The researchindicates that when the market is bullish, traders would take U-shaped selling strategy while initialholding is excessive. Incremental buying strategy may be adopted for appropriate optimal initialholding. ff initial holding amount is less at either long or short position, optimal trading strategy isthat first incremental buying, and then incremental selling. When traders hold excessive amount atshort position against bullish market, they would take incremental buying strategy. However, theoptimal strategies in bearish market address reverse outcomes that in bullish market. If market isneutral, the optimal strategy is degressive selling or incremental buying strategy. Lastly, this paperanalyses how liquidity affects optimal trading strategy.

  12. OPTIMASI NANOENKAPSULASI ASAP CAIR TEMPURUNG KELAPA DENGAN RESPONSE SURFACE METHODOLOGY DAN KARAKTERISASI NANOKAPSUL [Optimization of Coconut Shell Liquid Smoke Nanoencapsulation using Response Surface Methodology and Nanocapsules Characterization

    Directory of Open Access Journals (Sweden)

    Dego Yusa Ali

    2014-06-01

    Full Text Available Liquid smoke is impractical and easy to deteriorate, thus needs to be protected against deterioration. Spray drying technique is widely used to encapsule bioactive compounds. This study aims to determine the optimum encapsulant ratio and spray drying process to produce nanocapsule of liqud smoke. Nanocapsules production began with the mixing of encapsulant (chitosan and maltodextrin and the liquid smoke and then agitated until dissolved. The solution of nanoparticles was heated in a water bath at 45°C for 5 minutes and homogenized using a homogenizer at 4000 rpm for 1 min. The nanoparticle solutions was spray dried at various temperatures and feed flow rates. Optimization is accomplished by using Response Surface Methodology (RSM, and the parameters to be optimized were chitosan concentration, inlet air temperature and feed flow rate of the spray dryer based on total phenolic content. Samples were analyzed for viscosity, pH, phenols staining, total phenolic, total carbonil, total acidity content, encapsulation efficiency, morphology profiles, and particle size distribution. The results showed that the nanoparticles solution of liquid smoke had a pH ranged between 2.55-2.64 total soluble solids ranged between 14-14.8°Brix and viscosity ranged between 8.7-14.9 centipoise (cP. The total phenolic content of the nanocapsules ranged from 1.38 to 2.32% with an efficiency ranged from 22.25 to 37.44%, and water content ranged from 9.56 to 10.73% (dry basis. The optimum conditions for the highest value of total phenolic content were 0.12% chitosan concentration, 140.65°C inlet air temperature and feed flow rate at 5.29 mL/min. The results suggested that nanocapsules had spherical and wrinkle shape with an average size of nanocapsules of 29.16 nm.

  13. Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

    Science.gov (United States)

    Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

    2003-09-01

    A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development

  14. Optimization of a NH4PF6-enhanced, non-organic solvent, dual microextraction method for determination of phthalate metabolites in urine by high performance liquid chromatography.

    Science.gov (United States)

    Wu, Jia; Ye, Zhihan; Li, Xiaolong; Wang, Xuedong; Luo, Fangjun; Sheng, Bo; Li, Yiwei; Lyu, Jianxin

    2016-03-01

    In conventional ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) procedures, most of the IL disperser remains in the aqueous phase resulting in low recovery for moderately and weakly polar analytes due to the "carry-over effect". Herein, we successfully developed a "NH4PF6-enhanced, non-organic solvent, dual microextraction" method (ANSDM) for pretreatment of phthalate (PAE) metabolites with weak to moderate polarity. This method utilized in situ reaction of NH4PF6 as an ion-exchange reagent and disperser to realize two microextractions after using [C8MIM]PF6 as an extraction solvent and [C4MIM]BF4 as a disperser for conventional DLLME. Single-factor experiments, a two-level full factorial experimental design and central composite design were applied for optimizing operational parameters using 3D response surfaces and contour lines. Under optimized conditions, the newly developed method provided high extraction recoveries (93.8-99.1%) and low LODs (ca. 0.3μgL(-1)) for three phthalate metabolites in human urine. The primary advantages of the ANSDM method include: (1) integration of in situ reaction and conventional DLLME techniques to effectively extract both weak and moderately polar pollutants simultaneously; (2) non-organic solvent use in the microextraction procedure making the process safer and more environmental friendly; and (3) a time-saving, simple operation that is fully compatibility with HPLC analysis. To the best of our knowledge, our group is the first to develop the "non-organic solvent, dual microextraction" method and it has great potential as a sample pre-treatment technique for organic pollutants with weak to moderate polarity in biological and environmental matrices.

  15. 氧化亚铁硫杆菌的分离鉴定及培养条件优化%Isolation and identification of Thiobacillus ferrooxidans and optimization of its culture condition

    Institute of Scientific and Technical Information of China (English)

    庄贺; 沈俊剑; 黎俊; 谢鸿观; 雷泞菲

    2013-01-01

    [Objective] A strain with the ability of bioleaching was isolated.Its culture condition was optimized.[Methods] The strain was isolated from the soil collected from thermoelectric plant in Chengdu,whose taxonomic status was identified based on analysis of morphology characteristics,culture characteristics and 16S rDNA sequence.The optimization experiment was designed with Box-Behnken method in the software Design-Expert,in which the four factors of culture condition that initial pH,temperature,inoculum amount and liquid volume were investigated.Then the results were analyzed with the response surface analysis (RSA) and the optimal culture condition was determined.[Results] The isolated strain was Gram-negative and short-rod,which was named as Z1 and identified as Acidithiobacillus ferrooxidans strain by analysis of its 16S rDNA sequence.The optimal culture condition of the strain was determined,which was initial pH 1.8,optimum temperature 30 ℃,inoculum volume 14% and liquid volume 60 mL medium in a 250 mL flask.Under the optimum condition,the oxidation rate of ferrousion reached at 99.7%.[Conclusion] The strain Z1 was appreciated for bioleaching.%[目的]获得可用于浸矿的菌株,对其培养条件进行优化.[方法]从成都热电厂采集土样中分离得到一株菌株,分析该菌株的形态学特征、培养特征及16S rDNA序列,确定菌株的分类地位.利用Design-Expert软件中的Box-Behnken法设计实验,通过响应面分析对初始pH值、温度、接种量和装液量4个因素进行优化,确定其最适培养条件.[结果]获得菌株Z1,该菌为革兰氏阴性菌,短杆状,经16S rDNA鉴定为嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称At.f).确定菌株最适培养条件为:pH 1.8、温度30℃、接种量14%、装液量250 mL摇瓶装60 mL培养液.在此条件下,Z1的亚铁氧化率可达99.7%.[结论]Z1菌株适合于生物浸矿的应用.

  16. Thermal-hydraulic optimization of flexible transfer lines for liquid helium; Thermohydraulische Optimierung flexibler Transferleitungen fuer Fluessighelium

    Energy Technology Data Exchange (ETDEWEB)

    Dittmar, Nico; Haberstroh, Christoph; Hesse, U. [Technische Univ. Dresden (Germany). Bitzer-Stiftungsprofessur fuer Kaelte-, Kryo- und Kompressorentechnik; Wolfram, M.; Krzyzowski, M.; Raccanelli, A. [CryoVac Gesellschaft fuer Tieftemperaturtechnik mbH und Co. KG, Troisdorf (Germany)

    2014-07-01

    Cooling systems and applications at very low temperatures are based on the use of liquid helium as cryogenic agent; the normal boiling temperature of helium-4 is 4.2 K. Due to the restricted economic production possibilities and the high energetic expenditure for helium liquefaction an efficient and sustainable handling with the resources is recommended. In university facilities the liquid helium is usually stored in containers and filled into smaller containers for transport using cryogenic transfer lines. This procedure can cause 20% loss by evaporation due to heat input and friction pressure losses. The gaseous helium has to be collected for re-liquefaction. The contribution shows that using systematic measurements an increase of the transfer rate and the efficiency of the helium filling system can be reached by a modified transfer line design.

  17. Recovery of culturable of Escherichia coli O157:H7 during operation of a liquid-based bioaerosol sampler

    Science.gov (United States)

    Collection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler™ for up...

  18. Generation of HIV-1 Gag VLPs by transient transfection of HEK 293 suspension cell cultures using an optimized animal-derived component free medium.

    Science.gov (United States)

    Cervera, Laura; Gutiérrez-Granados, Sonia; Martínez, Marta; Blanco, Julià; Gòdia, Francesc; Segura, María Mercedes

    2013-07-20

    Virus-like particles (VLPs) offer great promise as candidates for new vaccine strategies. Large-scale approaches for the manufacturing of HIV-1 Gag VLPs have mainly focused on the use of the baculovirus expression system. In this work, the development and optimization of an HIV-1 Gag VLP production protocol by transient gene expression in mammalian cell suspension cultures is reported. To facilitate process optimization, a Gag-GFP fusion construct enabling the generation of fluorescent VLPs was used. The great majority of Gag-GFP present in cell culture supernatants was shown to be correctly assembled into virus-like particles of the expected size and morphology consistent with immature HIV-1 particles. Medium optimization was performed using design of experiments (DoE). Culture medium supplementation with non-animal derived components including recombinant proteins and lipids of synthetic or non-animal-derived origin resulted in improved HEK 293 cell growth and VLP production. The maximum cell density attained using the optimized Freestyle culture medium was 5.4×10(6)cells/mL in batch mode, almost double of that observed using the unsupplemented medium (2.9×10(6)cells/mL). Best production performance was attained when cells were transfected at mid-log phase (2-3×10(6)cells/mL) with medium exchange at the time of transfection using standard amounts of plasmid DNA and polyethylenimine. By using an optimized production protocol, VLP titers were increased 2.4-fold obtaining 2.8μg of Gag-GFP/mL or 2.7×10(9)VLPs/mL according to ELISA and nanoparticle tracking quantification analyses, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Optimization of the Culture Medium Composition to Improve the Production of Hyoscyamine in Elicited Datura stramonium L. Hairy Roots Using the Response Surface Methodology (RSM)

    Science.gov (United States)

    Ryad, Amdoun; Lakhdar, Khelifi; Majda, Khelifi-Slaoui; Samia, Amroune; Mark, Asch; Corinne, Assaf-Ducrocq; Eric, Gontier

    2010-01-01

    Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one-variable-at-a-time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO3−], [Ca2+] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experiment