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Sample records for acetate membrane electrophoresis

  1. A quantitative method for blood lipoproteins using cellulose acetate electrophoresis

    PubMed Central

    Magnani, H. N.; Howard, A. N.

    1971-01-01

    A rapid, inexpensive, and quantitative method is described for obtaining the levels of plasma very low, low, and high density lipoproteins using cellulose acetate electrophoresis and lipid assays without prior separation by ultracentrifuge or other techniques. It involves separation of the lipoproteins by cellulose acetate electrophoresis, followed by their identification with the ozone-Schiff reaction. The total lipoprotein concentration is estimated from the total plasma phospholipid, and the percentage of each component obtained by densitometric analysis of the stained electrophoretograms, using reflected light. For samples with a raised level of very low density lipoprotein, plasma triglyceride analysis is also required. The results obtained by the cellulose acetate electrophoresis method are in good agreement with those by the analytical ultracentrifuge and the preparative ultracentrifuge with refractometry. The theoretical assumptions on which the method is based have been shown to be valid. Images PMID:4110791

  2. High-flux cellulose acetate membranes

    SciTech Connect

    Boeddeker, K.W.; Finken, H.; Wenzlaff, A.

    1981-01-01

    Three routes to increase the permeate flux of asymmetric cellulose diacetate membranes of the Loeb-Sourirajan type were investigated: increasing the hydrophilicity of the membranes; increasing their compaction stability, and employing a swelling agent which allows for higher solvent-to-polymer ratio in the casting solution. The effect of casting solution composition on flux and rejection of formamide-modified cellulose acetate membrane is included, illustrating the general capability of this membrane type as function of solvent concentration. Membranes of casting solution composition cellulose diacetate/acetone/formamide 23/52/25 were used as reference membranes in the work. 6 figures. (DP)

  3. Cellulose Acetate Membranes: Electron Microscopy of Structure.

    PubMed

    Riley, R; Gardner, J O; Merten, U

    1964-02-21

    Electron photomicrographs of cellulose acetate membranes used in the reverse osmosis processof water desalination reveal a dense surface layer with a porous substructure. The high rate oftransmission for water can be correlated with the thickness of the dense layer on the air-driedsurface of the membrane.

  4. Fabricating PFPE Membranes for Capillary Electrophoresis

    NASA Technical Reports Server (NTRS)

    Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason

    2009-01-01

    A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).

  5. Supported Molecular Matrix Electrophoresis.

    PubMed

    Matsuno, Yu-Ki; Kameyama, Akihiko

    2015-01-01

    Mucins are difficult to separate using conventional gel electrophoresis methods such as SDS-PAGE and agarose gel electrophoresis, owing to their large size and heterogeneity. On the other hand, cellulose acetate membrane electrophoresis can separate these molecules, but is not compatible with glycan analysis. Here, we describe a novel membrane electrophoresis technique, termed "supported molecular matrix electrophoresis" (SMME), in which a porous polyvinylidene difluoride (PVDF) membrane filter is used to achieve separation. This description includes the separation, visualization, and glycan analysis of mucins with the SMME technique. PMID:26139278

  6. Fucoidan as an inhibitor of thermally induced collagen glycation examined by acetate electrophoresis.

    PubMed

    Pielesz, Anna; Paluch, Jadwiga

    2014-08-01

    Non-enzymatic glycation (Maillard reaction) in vitro could be a simple method to obtain glycoconjugates for studying their biological properties. Hence, fucoidan was retained by acetate electrophoresis indicating a strong interaction with the protein. A loss of colour in fucoidan bands was found for samples incubated with collagen as compared with samples of free fucoidan. Also under in vitro conditions at 100°C - simulating a sudden burn incident - fucoidan binds with collagen as a result of the Maillard reaction. In contrast, the colour of the fucoidan bands intensified for samples incubated with collagen, with the addition of glucose. Electrophoretic analyses were carried out after heating the samples to a temperature simulating a burn incident. The bands were found to intensify for samples incubated with collagen during a 30-day-long incubation. Thus, spontaneous in vitro glycation - i.e. without the addition of glucose - was confirmed. This process is highly intensified both by the temperature and time of incubation. For a sample incubated in vitro in a fucoidan solution containing glucose, glycation was confirmed in a preliminary FTIR and acetate electrophoresis examinations, occurring in collagen obtained from chicken skins. In particular, a new band emerging around 1746 cm(-1) was observed for above samples, as was its increasing intensity, as compared with samples without the addition of glucose. In the collagen glycation assay, while glucose reacts with collagen and forms cross-linked aggregates, fucoidan decreases the process of aggregation and recovery of native collagen.

  7. Continuous-flow electrophoresis: Membrane-associated deviations of buffer pH and conductivity

    NASA Technical Reports Server (NTRS)

    Smolka, A. J. K.; Mcguire, J. K.

    1978-01-01

    The deviations in buffer pH and conductivity which occur near the electrode membranes in continuous-flow electrophoresis were studied in the Beckman charged particle electrophoresis system and the Hanning FF-5 preparative electrophoresis instrument. The nature of the membranes separating the electrode compartments from the electrophoresis chamber, the electric field strength, and the flow rate of electrophoresis buffer were all found to influence the formation of the pH and conductivity gradients. Variations in electrode buffer flow rate and the time of electrophoresis were less important. The results obtained supported the hypothesis that a combination of Donnan membrane effects and the differing ionic mobilities in the electrophoresis buffer was responsible for the formation of the gradients. The significance of the results for the design and stable operation of continuous-flow electrophoresis apparatus was discussed.

  8. Dissolution control of Mg by cellulose acetate-polyelectrolyte membranes.

    PubMed

    Yliniemi, Kirsi; Wilson, Benjamin P; Singer, Ferdinand; Höhn, Sarah; Kontturi, Eero; Virtanen, Sannakaisa

    2014-12-24

    Cellulose acetate (CA)-based membranes are used for Mg dissolution control: the permeability of the membrane is adjusted by additions of the polyelectrolyte, poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). Spin-coated films were characterized with FT-IR, and once exposed to an aqueous solution the film distends and starts acting as a membrane which controls the flow of ions and H2 gas. Electrochemical measurements (linear sweep voltammograms, open-circuit potential, and polarization) show that by altering the CA:PDMAEMA ratio the dissolution rate of Mg can be controlled. Such a control over Mg dissolution is crucial if Mg is to be considered as a viable, temporary biomedical implant material. Furthermore, the accumulation of corrosion products between the membrane and the sample diminishes the undesirable effects of high local pH and H2 formation which takes place during the corrosion process.

  9. Ion selective permeation through cellulose acetate membranes in forward osmosis.

    PubMed

    Irvine, Gavin J; Rajesh, Sahadevan; Georgiadis, Michael; Phillip, William A

    2013-12-01

    Solute-solute interactions can have a dramatic impact on the permeation of solutes through dense polymeric membranes. In particular, understanding how solute-solute interactions can affect the design of osmotically driven membrane processes (ODMPs) is critical to the successful development of these emerging water treatment and energy generation processes. In this work, we investigate the influence that solute-solute interactions have on nitrate permeation through an asymmetric cellulose acetate forward osmosis membrane. A series of experiments that included systematic modifications to the cation paired with nitrate, the identity of the draw solute, and the solution pH were conducted. These experiments reveal that in the unique operating geometry of ODMPs, where solute containing solutions are present on both sides of the membrane, nitrate fluxes are significantly higher (>15 times in some cases) than predicted by existing models for solute permeation in ODMPs. The identity of the cation paired with nitrate influences the flux of nitrate; the identity of the cation in the draw solution does not affect the flux of nitrate; however, the identity of the anion in the draw solution has the most significant impact on the flux of nitrate. These results suggest that an ion exchange mechanism, which allows nitrate to switch rapidly with anions from the draw solution, is present when cellulose acetate based membranes are used in ODMPs.

  10. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    PubMed

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate.

  11. Surface modification of cellulose acetate membrane using thermal annealing to enhance produced water treatment

    NASA Astrophysics Data System (ADS)

    Kusworo, T. D.; Aryanti, N.; Firdaus, M. M. H.; Sukmawati, H.

    2015-12-01

    This study is performed primarily to investigate the effect of surface modification of cellulose acetate using thermal annealing on the enhancement of membrane performance for produced water treatment. In this study, Cellulose Acetate membranes were casted using dry/wet phase inversion technique. The effect of additive and post-treatment using thermal annealing on the membrane surface were examined for produced water treatment. Therma annealing was subjected to membrane surface at 60 and 70 °C for 5, 10 and 15 second, respectively. Membrane characterizations were done using membrane flux and rejection with produced water as a feed, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FTIR) analysis. Experimental results showed that asymmetric cellulose acetate membrane can be made by dry/wet phase inversion technique. The results from the Scanning Electron Microscopy (FESEM) analysis was also confirmed that polyethylene glycol as additivie in dope solution and thermal annealing was affected the morphology and membrane performance for produced water treatment, respectively. Scanning electron microscopy micrographs showed that the selective layer and the substructure of membrane became denser and more compact after the thermal annealing processes. Therefore, membrane rejection was significantly increased while the flux was slighty decreased, respectively. The best membrane performance is obtained on the composition of 18 wt % cellulose acetate, poly ethylene glycol 5 wt% with thermal annealing at 70° C for 15 second.

  12. Surface modification of cellulose acetate membrane using thermal annealing to enhance produced water treatment

    SciTech Connect

    Kusworo, T. D. Aryanti, N. Firdaus, M. M. H.; Sukmawati, H.

    2015-12-29

    This study is performed primarily to investigate the effect of surface modification of cellulose acetate using thermal annealing on the enhancement of membrane performance for produced water treatment. In this study, Cellulose Acetate membranes were casted using dry/wet phase inversion technique. The effect of additive and post-treatment using thermal annealing on the membrane surface were examined for produced water treatment. Therma annealing was subjected to membrane surface at 60 and 70 °C for 5, 10 and 15 second, respectively. Membrane characterizations were done using membrane flux and rejection with produced water as a feed, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FTIR) analysis. Experimental results showed that asymmetric cellulose acetate membrane can be made by dry/wet phase inversion technique. The results from the Scanning Electron Microscopy (FESEM) analysis was also confirmed that polyethylene glycol as additivie in dope solution and thermal annealing was affected the morphology and membrane performance for produced water treatment, respectively. Scanning electron microscopy micrographs showed that the selective layer and the substructure of membrane became denser and more compact after the thermal annealing processes. Therefore, membrane rejection was significantly increased while the flux was slighty decreased, respectively. The best membrane performance is obtained on the composition of 18 wt % cellulose acetate, poly ethylene glycol 5 wt% with thermal annealing at 70° C for 15 second.

  13. Synthesis and characterization of polyurethane-cellulose acetate blend membrane for chromium (VI) removal.

    PubMed

    Riaz, Tabinda; Ahmad, Adnan; Saleemi, Sidra; Adrees, Muhammad; Jamshed, Fahad; Hai, Abdul Moqeet; Jamil, Tahir

    2016-11-20

    Blended membranes of polyurethane and cellulose acetate were prepared, characterized and investigated for their performance. Various ratios of cellulose acetate were employed to prepare four different blend membranes. The characteristics of both pure and blend membranes were investigated and results were compared to distinguish their properties. Functional group analysis was carried out by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of pure and blend samples. Contact angle measurement and water content were evaluated to determine the membrane hydrophilicity. Moreover, the membrane morphology was studied by scanning electron microscopy (SEM). The membrane permeation properties and ability to reject chromium (VI) ions were tested at various pH and pressure by utilizing different salt concentrations. PMID:27561531

  14. Synthesis and characterization of polyurethane-cellulose acetate blend membrane for chromium (VI) removal.

    PubMed

    Riaz, Tabinda; Ahmad, Adnan; Saleemi, Sidra; Adrees, Muhammad; Jamshed, Fahad; Hai, Abdul Moqeet; Jamil, Tahir

    2016-11-20

    Blended membranes of polyurethane and cellulose acetate were prepared, characterized and investigated for their performance. Various ratios of cellulose acetate were employed to prepare four different blend membranes. The characteristics of both pure and blend membranes were investigated and results were compared to distinguish their properties. Functional group analysis was carried out by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of pure and blend samples. Contact angle measurement and water content were evaluated to determine the membrane hydrophilicity. Moreover, the membrane morphology was studied by scanning electron microscopy (SEM). The membrane permeation properties and ability to reject chromium (VI) ions were tested at various pH and pressure by utilizing different salt concentrations.

  15. Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 1: Cellulose acetate active layer membranes

    SciTech Connect

    Kulkarni, S.; Krause, S. ); Wignall, G.D. . Solid State Div.); Hammouda, B. . Center for High Resolution Neutron Scattering)

    1994-11-07

    The structure of ultrathin cellulose acetate membranes, known as active layer membranes, has been investigated using small-angle neutron scattering. These membranes are known to have structural and functional similarity to the surface or skin layer in commercial reverse-osmosis (RO) membranes and hence are useful model systems for understanding the structure of the RO membrane skin layer. Active layer membranes were studied after swelling them with either D[sub 2]O or CD[sub 3]OD. The results in both cases clearly indicated the presence of very small (10--20 [angstrom]) porous structures in the membrane. The presence of such pores has been a subject of long-standing controversy in this area. The data were analyzed using a modified Debye-Bueche analysis and the resultant membrane structure was seen to agree well with structural information from electron microscopic studies. Finally, a possible explanation for the differences in scattering observed between the D[sub 2]O swollen membranes and the CD[sub 3]OD swollen membranes has been presented.

  16. Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates

    SciTech Connect

    Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

    2006-01-01

    Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

  17. Study of ABO blood types by combining membrane electrophoresis with surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Lin, Juqiang; Huang, Zufang; Sun, Liqing; Shao, Yonghong; Lu, Peng; Shi, Wei; Lin, Jinyong; Chen, Rong

    2012-12-01

    The molecular characterization of ABO blood types, which is clinically significant in blood transfusion, has clinical and anthropological importance. Polymerase chain reaction sequence-based typing (PCR-SBT) is one of the most commonly used methods for the analysis of genetic bases of ABO blood types. However, such methods as PCR-SBT are time-consuming and are high in demand of equipments and manipulative skill. Here we showed that membrane electrophoresis based SERS method employed for studying the molecular bases of ABO blood types can provide rapidand easy-operation with high sensitivity and specificity. The plasma proteins were firstly purified by membrane electrophoresis and then mixed with silver nanoparticles to perform SERS detection. We use this method to classify different blood types, including blood type A (n=13), blood type B (n=9) and blood type O (n=10). Combination of principal component analysis (PCA) and liner discriminant analysis (LDA) was then performed on the SERS spectra of purified albumin, showing good classification results among different blood types. Our experimental outcomes represent a critical step towards the rapid, convenient and accurate identification of ABO blood types.

  18. Performance of cellulose acetate butyrate membranes in hyperfiltration of sodium chloride and urea feed solution

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Leban, M.

    1973-01-01

    Cellulose acetate butyrate (CAB) membranes are shown to give high salt and urea rejection with water flux of about 3 gallons/sq ft per day at 600 psig. Membranes prepared from a formulation containing glyoxal show a significant increase in flux and decrease in salt and urea rejection with drying time. Zero drying time gives maximum urea and salt rejection and is therefore most suitable for hyperfiltration of sodium chloride and urea feed solution.

  19. Tailoring the properties of asymmetric cellulose acetate membranes by gas plasma etching.

    PubMed

    Olde Riekerink, M B; Engbers, G H M; Wessling, M; Feijen, J

    2002-01-15

    Cellulose triacetate (CTA) ultrafilters and cellulose acetate blend (CAB) desalination membranes were treated with a radiofrequency gas plasma (tetrafluoromethane (CF(4)) or carbon dioxide (CO(2)), 47-49 W, 0.04-0.08 mbar). Treatment times were varied between 15 s and 120 min. The plasma-treated top layer of the membranes was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle measurements to obtain information about surface structure, chemistry, and wettability, respectively. The membrane properties (e.g., permeability, selectivity, fouling) were studied by waterflux measurements, molecular weight cutoff measurements, and fouling experiments with bovine serum albumin. CO(2) plasma treatment resulted in gradual etching of the membrane's dense top layer. Permeation and selectivity changed significantly for treatment times of 0-15 min for CTA and 5-60 min for CAB membranes. Moreover, CTA membranes were hydrophilized during CO(2) plasma treatment whereas CF(4) plasma treatment led to hydrophobic surfaces due to strong fluorination of the top layer. This study shows that gas plasma etching can tailor the properties of asymmetric cellulose acetate membranes by simultaneously modifying the chemistry and structure of the top layer. The low fouling properties of CTA membranes were thereby largely maintained.

  20. Self-sterilized composite membranes of cellulose acetate/polyethylene glycol for water desalination.

    PubMed

    Ahmad, Adnan; Jamshed, Fahad; Riaz, Tabinda; Gul, Sabad-E-; Waheed, Sidra; Sabir, Aneela; AlAnezi, Adnan Alhathal; Adrees, Muhammad; Jamil, Tahir

    2016-09-20

    Cellulose acetate/Polyethylene glycol-600 composite membranes were fabricated by two step phase inversion procedure and modified by in-situ reduction of silver nitrate. FTIR spectra demonstrated the existence of functional groups for bonding of silver with oxygen at 370cm(-1), 535cm(-1). The XRD diffractogram indicates characteristic peaks at 2θ values of 38.10°, 44.30°, 64.40°, and 77.30° which confirm the successful incorporation of silver within matrix of composite membranes. The morphology of composite membranes with appearances of spongy voids was exemplified from the scanning electron microscope. The atomic force microscopy was used to determine the increase in the surface roughness of the membranes. The increase in hydrophilicity, measured through contact angle, is rendered to the embedment of silver. The modification of membranes increased the flux from 0.80 to 0.95L/hr.m(2). The resulting membranes have outstanding ability to fight against gram negative Escherichia Coli and Bacillus Sabtilus. The novel cellulose acetate/polyethylene glycol membranes customized with silver have paved the path for evolution of axenic membranes. PMID:27261744

  1. Self-sterilized composite membranes of cellulose acetate/polyethylene glycol for water desalination.

    PubMed

    Ahmad, Adnan; Jamshed, Fahad; Riaz, Tabinda; Gul, Sabad-E-; Waheed, Sidra; Sabir, Aneela; AlAnezi, Adnan Alhathal; Adrees, Muhammad; Jamil, Tahir

    2016-09-20

    Cellulose acetate/Polyethylene glycol-600 composite membranes were fabricated by two step phase inversion procedure and modified by in-situ reduction of silver nitrate. FTIR spectra demonstrated the existence of functional groups for bonding of silver with oxygen at 370cm(-1), 535cm(-1). The XRD diffractogram indicates characteristic peaks at 2θ values of 38.10°, 44.30°, 64.40°, and 77.30° which confirm the successful incorporation of silver within matrix of composite membranes. The morphology of composite membranes with appearances of spongy voids was exemplified from the scanning electron microscope. The atomic force microscopy was used to determine the increase in the surface roughness of the membranes. The increase in hydrophilicity, measured through contact angle, is rendered to the embedment of silver. The modification of membranes increased the flux from 0.80 to 0.95L/hr.m(2). The resulting membranes have outstanding ability to fight against gram negative Escherichia Coli and Bacillus Sabtilus. The novel cellulose acetate/polyethylene glycol membranes customized with silver have paved the path for evolution of axenic membranes.

  2. Hydrophilicity and antifouling property of membrane materials from cellulose acetate/polyethersulfone in DMAc.

    PubMed

    Sun, Zhonghua; Chen, Fushan

    2016-10-01

    In this study, cellulose acetate (CA) was blended with polyethersulfone (PES) to endow the ultrafiltration membrane with the improved hydrophilicity and antifouling property by using N,N-dimethylacetamide (DMAc) as the solvent. The effects of blend composition and evaporation time on the mechanical strength and pure water flux were investigated. It was found that the optimal composition of the casting solution was: 18wt% (PES), 4wt% (Polyvinylpyrrolidone K30), 3wt% (CA) and 20s (Evaporation time). The characteristics of CA-PES blend membranes were investigated through the methods of contact angle goniometer, antifouling property, compatibility, thermo gravimetric analysis and SEM. The results showed that the hydrophilicity and antifouling property of CA-PES ultrafiltration membranes were enhanced in comparison with the pure PES membranes. The CA-PES membranes exhibited semi-compatibility and good thermal stability below 270°C. This study provided a potential industrial application prospect of CA-PES membranes prepared in DMAc.

  3. Electrospinning of silver nanoparticles loaded highly porous cellulose acetate nanofibrous membrane for treatment of dye wastewater

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Ma, Qian; Wang, Shu-Dong; Liu, Hua; Zhang, Sheng-Zhong; Bao, Wei; Zhang, Ke-Qin; Ling, Liang-Zhong

    2016-01-01

    In this paper, silver nanoparticles (NPs) were reduced form silver nitrate. Morphology and distribution of the synthesized silver NPs were characterized. In order to obtain cellulose acetate (CA), nanofibrous membrane with high effective adsorption performance to carry silver NPs for treatment of dye wastewater, different solvent systems were used to fabricate CA nanofibrous membranes with different morphologies and porous structures via electrospinning. Morphologies and structures of the obtained CA nanofibrous membranes were compared by scanning electron microscopy (SEM), which showed that CA nanofibrous membrane obtained from acetone/dichloromethane (1/2, v/v) was with the highly porous structure. SEM, energy-dispersive spectrometry and Fourier transform infrared spectrometry showed that the silver NPs were effectively incorporated in the CA nanofibrous membrane and the addition of silver NPs did not damage the porous structure of the CA nanofibrous membrane. Adsorption of dye solution (rhodamine B aqueous solution) revealed that the highly porous CA nanofibrous membrane exhibited effective adsorption performance and the addition of silver NPs did not affect the adsorption of the dye. Antibacterial property of the CA nanofibrous membrane showed that the silver-loaded highly porous CA nanofibrous membrane had remarkable antibacterial property when compared to the CA nanofibrous membrane without silver NPs. The silver-loaded highly porous CA nanofibrous membrane could be considered as an ideal candidate for treatment of the dye wastewater.

  4. Effect of coagulant bath on the gas permeation properties of cellulose acetate asymmetric membrane

    NASA Astrophysics Data System (ADS)

    Mohamed, F.; Hasbullah, H.; Jami'an, W. N. R.; Salleh, W. N. H. W.; Ibrahim, N.; Ali, R. R.

    2016-06-01

    Membrane based gas separation process technology has been recognized as one of the most efficient and advanced unit operation for gas separation. One of the problems in membrane gas separation is membrane performance. This paper explores the application of cellulose acetate (CA) membrane for natural gas purification and separation by improving its permeability and selectivity. The main interest in this research is to study the effect of quench medium on the gas separation performance towards its physical characteristics and gas separation performance of CA membrane. Cellulose acetate polymer was dissolved in n- methyl-2-pyrrolidone solvent and casted onto a glass plate using a pneumatically controlled casting system with fixed shear rate and solvent evaporation times. The parameter varied was the non-solvent used as quench medium during membrane post treatment that were methanol and n-hexane. The different quench media as post treatment affected the O2 and N2 gas permeation and O2/N2 selectivity as well as the tensile strength of the flat sheet asymmetric membrane. Combination of methanol and n-hexane as quench media gave the best result than the other steps. This solvent exchange step influenced the morphology by producing thin skin layer and thus gives better gas separation performance than other steps

  5. Alginate fouling reduction of functionalized carbon nanotube blended cellulose acetate membrane in forward osmosis.

    PubMed

    Choi, Hyeon-Gyu; Son, Moon; Yoon, SangHyeon; Celik, Evrim; Kang, Seoktae; Park, Hosik; Park, Chul Hwi; Choi, Heechul

    2015-10-01

    Functionalized multi-walled carbon nanotube blended cellulose acetate (fCNT-CA) membranes were synthesized for forward osmosis (FO) through phase inversion. The membranes were characterized through SEM, FTIR, and water contact angle measurement. AFM was utilized to investigate alginate fouling mechanism on the membrane. It reveals that the fCNT contributes to advance alginate fouling resistance in FO (57% less normalized water flux decline for 1% fCNT-CA membrane was observed than that for bare CA membrane), due to enhanced electrostatic repulsion between the membrane and the alginate foulant. Furthermore, it was found that the fCNT-CA membranes became more hydrophilic due to carboxylic groups in functionalized carbon nanotube, resulting in approximately 50% higher water-permeated flux than bare CA membrane. This study presents not only the fabrication of fCNT-CA membrane and its application to FO, but also the quantification of the beneficial role of fCNT with respect to alginate fouling in FO.

  6. Effect of evaporation time on cellulose acetate membrane for gas separation

    NASA Astrophysics Data System (ADS)

    Jami'an, W. N. R.; Hasbullah, H.; Mohamed, F.; Yusof, N.; Ibrahim, N.; Ali, R. R.

    2016-06-01

    Throughout this decades, membrane technology has been the desirable option among the others gas separation technologies. However, few issues have been raised regarding the membrane gas separation application including the trade-off between its permeability and selectivity and also its effects towards environment. Therefore, for this research, a biopolymer membrane for gas separation application will be developed with reasonably high on both permeability and selectivity. The main objective of this research is to study the effect of solvent evaporation time on the flat sheet asymmetric membrane morphology and gas separation performance. The membranes were produced by a simple dry/wet phase inversion technique using a pneumatically controlled casting system. The dope solution for the membrane casting was prepared by dissolving the cellulose acetate (CA) polymer in N-Methyl-2-pyrrolidone (NMP) and the solvent evaporation time was varied. Permeability and selectivity of the membrane was performed by using pure gases of carbon dioxide, CO2 and methane, CH4. The increase in solvent evaporation time had improved the membrane morphologies as the porosity of the membrane surface decrease and formation of a more mature skin layer. The gas permeation tests determined that increasing in solvent evaporation time had increased the selectivity of CO2/CH4 but reduce the permeability of both gases

  7. Fabrication and performance of PET mesh enhanced cellulose acetate membranes for forward osmosis.

    PubMed

    Li, Guoliang; Wang, Jun; Hou, Deyin; Bai, Yu; Liu, Huijuan

    2016-07-01

    Polyethylene terephthalate mesh (PET) enhanced cellulose acetate membranes were fabricated via a phase inversion process. The membrane fabrication parameters that may affect the membrane performance were systematically evaluated including the concentration and temperature of the casting polymer solution and the temperature and time of the evaporation, coagulation and annealing processes. The water permeability and reverse salt flux were measured in forward osmosis (FO) mode for determination of the optimal membrane fabrication conditions. The optimal FO membrane shows a typical asymmetric sandwich structure with a mean thickness of about 148.2μm. The performance of the optimal FO membrane was tested using 0.2mol/L NaCl as the feed solution and 1.5mol/L glucose as the draw solution. The membrane displayed a water flux of 3.47L/(m(2)·hr) and salt rejection of 95.48% in FO mode. While in pressure retarded osmosis (PRO) mode, the water flux was 4.74L/(m(2)·hr) and salt rejection 96.03%. The high ratio of water flux in FO mode to that in PRO mode indicates that the fabricated membrane has a lower degree of internal concentration polarization than comparable membranes. PMID:27372114

  8. Separation of macromolecular proteins and removal of humic acid by cellulose acetate modified UF membranes.

    PubMed

    Kanagaraj, P; Nagendran, A; Rana, D; Matsuura, T

    2016-08-01

    Surface modifying macromolecules (SMMs) were synthesized with various polyurethane pre polymers end-capped with different groups and blended into the casting solution of cellulose acetate (CA) to prepare surface modified ultra-filtration (UF) membranes for water filtration applications. The surface modification of the CA membranes was confirmed by the FTIR and static contact angle (SCA) measurements. The membranes so prepared had the typical characteristics of UF membranes as confirmed by scanning electron microscopy (SEM). Membrane properties were studied in terms of membrane compaction, percentage water content (%WC), pure water flux (PWF), membrane hydraulic resistance (Rm), molecular weight cut-off (MWCO), average pore size and porosity. The result showed that PWF, %WC, MWCO and pore size increased whereas the Rm decreased by the addition of SMMs. The significant effect of SMMs on the fouling by humic acid (HA) was also observed. It was found that the cSMM-3 membrane, in which SMM was synthesized with diethylene glycol (DEG) and hydroxyl benzene sulfonate (HBS) was blended, had the highest flux recovery ratio FRR (84.6%), as well as the lowest irreversible fouling (15.4%), confirming their improved antifouling properties. Thus, the SMM modified CA membranes had proven, to play an important role in the water treatment by UF. PMID:27118046

  9. Separation of macromolecular proteins and removal of humic acid by cellulose acetate modified UF membranes.

    PubMed

    Kanagaraj, P; Nagendran, A; Rana, D; Matsuura, T

    2016-08-01

    Surface modifying macromolecules (SMMs) were synthesized with various polyurethane pre polymers end-capped with different groups and blended into the casting solution of cellulose acetate (CA) to prepare surface modified ultra-filtration (UF) membranes for water filtration applications. The surface modification of the CA membranes was confirmed by the FTIR and static contact angle (SCA) measurements. The membranes so prepared had the typical characteristics of UF membranes as confirmed by scanning electron microscopy (SEM). Membrane properties were studied in terms of membrane compaction, percentage water content (%WC), pure water flux (PWF), membrane hydraulic resistance (Rm), molecular weight cut-off (MWCO), average pore size and porosity. The result showed that PWF, %WC, MWCO and pore size increased whereas the Rm decreased by the addition of SMMs. The significant effect of SMMs on the fouling by humic acid (HA) was also observed. It was found that the cSMM-3 membrane, in which SMM was synthesized with diethylene glycol (DEG) and hydroxyl benzene sulfonate (HBS) was blended, had the highest flux recovery ratio FRR (84.6%), as well as the lowest irreversible fouling (15.4%), confirming their improved antifouling properties. Thus, the SMM modified CA membranes had proven, to play an important role in the water treatment by UF.

  10. Fabrication and performance of PET mesh enhanced cellulose acetate membranes for forward osmosis.

    PubMed

    Li, Guoliang; Wang, Jun; Hou, Deyin; Bai, Yu; Liu, Huijuan

    2016-07-01

    Polyethylene terephthalate mesh (PET) enhanced cellulose acetate membranes were fabricated via a phase inversion process. The membrane fabrication parameters that may affect the membrane performance were systematically evaluated including the concentration and temperature of the casting polymer solution and the temperature and time of the evaporation, coagulation and annealing processes. The water permeability and reverse salt flux were measured in forward osmosis (FO) mode for determination of the optimal membrane fabrication conditions. The optimal FO membrane shows a typical asymmetric sandwich structure with a mean thickness of about 148.2μm. The performance of the optimal FO membrane was tested using 0.2mol/L NaCl as the feed solution and 1.5mol/L glucose as the draw solution. The membrane displayed a water flux of 3.47L/(m(2)·hr) and salt rejection of 95.48% in FO mode. While in pressure retarded osmosis (PRO) mode, the water flux was 4.74L/(m(2)·hr) and salt rejection 96.03%. The high ratio of water flux in FO mode to that in PRO mode indicates that the fabricated membrane has a lower degree of internal concentration polarization than comparable membranes.

  11. Cellulose Acetate 398-10 Asymmetric Membrane Capsules for Osmotically Regulated Delivery of Acyclovir.

    PubMed

    Sonkar, Alka; Kumar, Anil; Pathak, Kamla

    2016-01-01

    The study was aimed at developing cellulose acetate asymmetric membrane capsules (AMCs) of acyclovir for its controlled delivery at the absorption site. The AMCs were prepared by phase inversion technique using wet process. A 2(3) full factorial design assessed the effect of independent variables (level(s) of polymer, pore former, and osmogen) on the cumulative drug release from AMCs. The buoyant optimized formulation F7 (low level of cellulose acetate; high levels of both glycerol and sodium lauryl sulphate) displayed maximum drug release of 97.88 ± 0.77% in 8 h that was independent of variation in agitational intensity and intentional defect on the cellulose acetate AMC. The in vitro data best fitted zero-order kinetics (r (2) = 0.9898). SEM micrograph of the transverse section confirmed the asymmetric nature of the cellulose acetate capsular membrane. Statistical analysis by Design Expert software indicated no interaction between the independent variables confirming the efficiency of the design in estimating the effects of variables on drug release. The optimized formulation F7 (desirability = 0.871) displayed sustenance of drug release over the drug packed in AMC in pure state proving the superiority of osmotically active formulation. Conclusively the AMCs have potential for controlled release of acyclovir at its absorption site.

  12. Cellulose Acetate 398-10 Asymmetric Membrane Capsules for Osmotically Regulated Delivery of Acyclovir

    PubMed Central

    Sonkar, Alka; Kumar, Anil; Pathak, Kamla

    2016-01-01

    The study was aimed at developing cellulose acetate asymmetric membrane capsules (AMCs) of acyclovir for its controlled delivery at the absorption site. The AMCs were prepared by phase inversion technique using wet process. A 23 full factorial design assessed the effect of independent variables (level(s) of polymer, pore former, and osmogen) on the cumulative drug release from AMCs. The buoyant optimized formulation F7 (low level of cellulose acetate; high levels of both glycerol and sodium lauryl sulphate) displayed maximum drug release of 97.88 ± 0.77% in 8 h that was independent of variation in agitational intensity and intentional defect on the cellulose acetate AMC. The in vitro data best fitted zero-order kinetics (r2 = 0.9898). SEM micrograph of the transverse section confirmed the asymmetric nature of the cellulose acetate capsular membrane. Statistical analysis by Design Expert software indicated no interaction between the independent variables confirming the efficiency of the design in estimating the effects of variables on drug release. The optimized formulation F7 (desirability = 0.871) displayed sustenance of drug release over the drug packed in AMC in pure state proving the superiority of osmotically active formulation. Conclusively the AMCs have potential for controlled release of acyclovir at its absorption site. PMID:26981319

  13. Removal of acetic acid from simulated hemicellulosic hydrolysates by emulsion liquid membrane with organophosphorus extractants.

    PubMed

    Lee, Sang Cheol

    2015-09-01

    Selective removal of acetic acid from simulated hemicellulosic hydrolysates containing xylose and sulfuric acid was attempted in a batch emulsion liquid membrane (ELM) system with organophosphorus extractants. Various experimental variables were used to develop a more energy-efficient ELM process. Total operation time of an ELM run with a very small quantity of trioctylphosphine oxide as the extractant was reduced to about a third of those required to attain almost the same extraction efficiency as obtained in previous ELM works without any extractant. Under specific conditions, acetic acid was selectively separated with a high degree of extraction and insignificant loss of xylose, and its purity and enrichment ratio in the stripping phase were higher than 92% and 6, respectively. Also, reused organic membrane solutions exhibited the extraction efficiency as high as fresh organic solutions did. These results showed that the current ELM process would be quite practical.

  14. Comparison of diffusion by anionic surfactants through cellulose acetate and collagen membranes.

    PubMed

    García Ramón, M T; Ribosa, I; Leal, J S; Parra, J L

    1989-06-01

    Synopsis From a dermatological point of view, it is important to know what is the irritation potential of surfactants on human skin. Recent research trends have been oriented towards the establishment of new 'in vitro' techniques that will avoid animal experimentation. In this paper, some results on the rate of diffusion of different anionic surfactants through both cellulose acetate and collagen membranes are described. A correlation between results of diffusion through the protein membrane and results published on the same surfactants and their irritation potential during 'in vivo' experiments appears possible.

  15. Transport of lactate and acetate through the energized cytoplasmic membrane of Escherichia coli

    SciTech Connect

    Axe, D.D.; Bailey, J.E.

    1995-07-05

    Escherichia coli produces lactate and acetate in significant amounts during both aerobic and anaerobic glycolysis. A model describing the mechanism of protein-mediated lactate transport has previously been proposed. A simple theoretical analysis here indicates that the proposed model would drain cellular energy resources by catalytically dissipating the proton-motive force. An experimental analysis of lactate and acetate transport employs nuclear magnetic resonance (NMR) spectroscopy to measure the relative concentrations of these end products on the two sides of the cytoplasmic membrane of anaerobically glycolyzing cells. Comparison of measured concentration ratios of those expected at equilibrium for various transport modes indicates that acetate is a classical uncoupling agent, permeating the membrane at comparable rates in the dissociated and undissociated forms. The lactate concentration ratio changes markedly after an initial period of sustained glycolysis. This change is most readily explained as resulting from a lactate transport system that responds to an indicator of glycolytic activity. The data further indicate that lactate permeates the membrane in both dissociated and undissociated forms. Both acids, then, are capable of catalytically dissipating the proton-motive force.

  16. Effects of octreotide acetate and amniotic membrane on wound healing in experimental glaucoma surgery.

    PubMed

    Demir, Tamer; Turgut, Burak; Celiker, Ulku; Ozercan, Ibrahim; Ulas, Fatih; Akyol, Nuray

    2003-09-01

    Wound healing affects the success of glaucoma filtering surgery. Antimetabolites and antifibrotic agents are used in the modulation of surgical trauma. This study is performed to evaluate the effects of amniotic membrane and octreotide acetate on wound healing. Thirty pigmented rabbits were divided into three groups each including 10 animals. Trabeculectomy and topical postoperative prednisolone sodium phosphate four times daily for 7 days were applied to one eye of all the rabbits. After trabeculectomy, octreotide 10 microg three times daily applied topically to the octreotide group for 14 days and amniotic membrane transplantation was performed by suturing amniotic membrane between scleral flap and sclera to the amniotic membrane group. The operated eyes of the rabbits were enucleated on the 14th day of the operation and histopathological specimens were obtained from the bleb sites and they were evaluated by light microscope. Fibroblast and macrophage number per cm2 were counted and the average values were calculated. Compared with the control group, the fibroblasts and macrophages significantly decreased in the other two groups (p < 0.0001, p < 0.0001, respectively). The mean number of fibroblasts was lower than those of the control and amniotic membrane groups (p < 0.0001, p < 0.0001, respectively). Similarly the mean macrophage number was significantly lower in the octreotide group versus the control and amniotic membrane groups (p < 0.0001, p < 0.01, respectively). Octreotide administration and amniotic membrane transplantation might be alternative treatments in modulating the wound healing after trabeculectomy.

  17. Two-dimensional polyacrylamide-gel electrophoresis of the proteins and glycoproteins of purified human platelet surface and intracellular membranes.

    PubMed

    Hack, N; Crawford, N

    1984-08-15

    By using highly purified surface and intracellular membrane fractions prepared from human platelets by free-flow electrophoresis, the polypeptide and glycopeptides of these membranes have been characterized by high-resolution gel electrophoresis under reducing and non-reducing conditions. Silver staining and a variety of glycoprotein-staining procedures have been applied to identify the major components. The principal finding was the clear disparity between the distribution patterns for these two membrane fractions. There are proportionately more low-Mr acidic components present in the intracellular membrane than in the surface-derived membrane. Of the major platelet surface glycoproteins GPIb, IIb, IIIa and IIIb (or IV) well expressed in the surface membrane only, GPIIb and IIIa appear as trace components in the intracellular membrane. The cytoskeleton proteins, actin, myosin, tropomyosin, actin-binding protein and alpha-actinin are prominent features of the surface membrane and essentially absent from the intracellular membrane. Neuraminidase treatment at the whole-cell level, before homogenization, which is an essential requirement for good resolution of the two membrane subfractions, modifies a number of the glycoprotein subunits with respect to their pI characteristics, suggesting much molecular micro-heterogeneity with respect to sialic acid content. A comparison of the staining characteristics of the major glycoproteins with periodic acid/Schiff's reagent and concanavalin A/peroxidase detection and a combined procedure revealed significant differences in associated carbohydrate structures, and the major concanavalin A-binding component was shown to be GPIIIa. These observations are discussed in the context of functional activities of both membrane systems in the physiological behaviour of the platelet.

  18. Silver staining of proteins on electroblotting membranes and intensification of silver staining of proteins separated by polyacrylamide gel electrophoresis.

    PubMed

    Sørensen, Birgitte Kjaer; Højrup, Peter; Østergård, Erik; Jørgensen, Charlotte Svaerke; Enghild, Jan; Ryder, Lisa Rebekka; Houen, Gunnar

    2002-05-01

    A fast and convenient method for silver staining of proteins on electroblotting membranes was developed based on Gallyas' histochemical intensifier and applied to human endothelial cell proteins separated by one- and two-dimensional electrophoresis and electroblotted to polyvinyl difluoride membranes. The method allowed detection of proteins on membranes with a sensitivity equal to the sensitivity of the most sensitive silver-staining protocols for electrophoresis gels. Also, the method was compatible with preceding immunostaining on the same membrane. Furthermore, an intensifying method for proteins in silver-stained SDS-PAGE gels was developed based on Gallyas' histochemical intensifier. This method was applied to proteins separated by one- and two-dimensional gel electrophoresis and visualized by one of several silver-staining methods. Maximal intensification was achieved for the less sensitive but fast acidic silver-staining protocols, but even for the very sensitive alkaline protocols a significant increase in signal to noise ratio was obtained. In particular, negatively stained or invisible proteins on the silver-stained gels were found to be visualized by the Gallyas stain. Proteins from silver-stained and Gallyas-stained gels were identified by mass spectrometry, and the intensification procedure was fully compatible with mass spectrometry. PMID:11969186

  19. Morphological analysis of Polyethersulfone/polyvinyl Acetate blend membrane synthesized at various polymer concentrations

    NASA Astrophysics Data System (ADS)

    Hadi, S. H. A. A.; Mannan, H. A.; Mukhtar, H.; Shaharun, M. S.; Murugesan, T.

    2016-06-01

    This paper reports the effect of varying polymer concentration i.e. solvent/polymer ratio on the morphology and gas transport behaviour of polyethersulfone/polyvinyl acetate blend membrane. The solvent used was dimethylformamide, while the manipulated variable was polymer concentration. The concentrations were varied from 75-90 weight % solvent. A homogeneous surface with dense cross-section structure membranes were successfully developed as deduced from FESEM images. The permeability of CO2 and CH4 gases increased with increasing polymer concentration and an improved CO2/CH4 selectivity was observed. These observation made from the characterization justified the applicability of the blend to be synthesized as membrane for gas separation.

  20. Electrospun cellulose acetate composites containing supported metal nanoparticles for antifungal membranes.

    PubMed

    Quirós, Jennifer; Gonzalo, Soledad; Jalvo, Blanca; Boltes, Karina; Perdigón-Melón, José Antonio; Rosal, Roberto

    2016-09-01

    Electrospun cellulose acetate composites containing silver and copper nanoparticles supported in sepiolite and mesoporous silica were prepared and tested as fungistatic membranes against the fungus Aspergillus niger. The nanoparticles were in the 3-50nm range for sepiolite supported materials and limited by the size of mesopores (5-8nm) in the case of mesoporous silica. Sepiolite and silica were well dispersed within the fibers, with larger aggregates in the micrometer range, and allowed a controlled release of metals to create a fungistatic environment. The effect was assessed using digital image analysis to evaluate fungal growth rate and fluorescence readings using a viability stain. The results showed that silver and copper nanomaterials significantly impaired the growth of fungi when the spores were incubated either in direct contact with particles or included in cellulose acetate composite membranes. The fungistatic effect took place on germinating spores before hyphae growth conidiophore formation. After 24h the cultures were separated from fungistatic materials and showed growth impairment only due to the prior exposure. Growth reduction was important for all the particles and membranes with respect to non-exposed controls. The effect of copper and silver loaded materials was not significantly different from each other with average reductions around 70% for bare particles and 50% for membranes. Copper on sepiolite was particularly efficient with a decrease of metabolic activity of up to 80% with respect to controls. Copper materials induced rapid maturation and conidiation with fungi splitting in sets of subcolonies. Metal-loaded nanomaterials acted as reservoirs for the controlled release of metals. The amount of silver or copper released daily by composite membranes represented roughly 1% of their total load of metals. Supported nanomaterials encapsulated in nanofibers allow formulating active membranes with high antifungal performance at the same time

  1. Electrospun cellulose acetate composites containing supported metal nanoparticles for antifungal membranes.

    PubMed

    Quirós, Jennifer; Gonzalo, Soledad; Jalvo, Blanca; Boltes, Karina; Perdigón-Melón, José Antonio; Rosal, Roberto

    2016-09-01

    Electrospun cellulose acetate composites containing silver and copper nanoparticles supported in sepiolite and mesoporous silica were prepared and tested as fungistatic membranes against the fungus Aspergillus niger. The nanoparticles were in the 3-50nm range for sepiolite supported materials and limited by the size of mesopores (5-8nm) in the case of mesoporous silica. Sepiolite and silica were well dispersed within the fibers, with larger aggregates in the micrometer range, and allowed a controlled release of metals to create a fungistatic environment. The effect was assessed using digital image analysis to evaluate fungal growth rate and fluorescence readings using a viability stain. The results showed that silver and copper nanomaterials significantly impaired the growth of fungi when the spores were incubated either in direct contact with particles or included in cellulose acetate composite membranes. The fungistatic effect took place on germinating spores before hyphae growth conidiophore formation. After 24h the cultures were separated from fungistatic materials and showed growth impairment only due to the prior exposure. Growth reduction was important for all the particles and membranes with respect to non-exposed controls. The effect of copper and silver loaded materials was not significantly different from each other with average reductions around 70% for bare particles and 50% for membranes. Copper on sepiolite was particularly efficient with a decrease of metabolic activity of up to 80% with respect to controls. Copper materials induced rapid maturation and conidiation with fungi splitting in sets of subcolonies. Metal-loaded nanomaterials acted as reservoirs for the controlled release of metals. The amount of silver or copper released daily by composite membranes represented roughly 1% of their total load of metals. Supported nanomaterials encapsulated in nanofibers allow formulating active membranes with high antifungal performance at the same time

  2. Hydrophilicity and antifouling property of membrane materials from cellulose acetate/polyethersulfone in DMAc.

    PubMed

    Sun, Zhonghua; Chen, Fushan

    2016-10-01

    In this study, cellulose acetate (CA) was blended with polyethersulfone (PES) to endow the ultrafiltration membrane with the improved hydrophilicity and antifouling property by using N,N-dimethylacetamide (DMAc) as the solvent. The effects of blend composition and evaporation time on the mechanical strength and pure water flux were investigated. It was found that the optimal composition of the casting solution was: 18wt% (PES), 4wt% (Polyvinylpyrrolidone K30), 3wt% (CA) and 20s (Evaporation time). The characteristics of CA-PES blend membranes were investigated through the methods of contact angle goniometer, antifouling property, compatibility, thermo gravimetric analysis and SEM. The results showed that the hydrophilicity and antifouling property of CA-PES ultrafiltration membranes were enhanced in comparison with the pure PES membranes. The CA-PES membranes exhibited semi-compatibility and good thermal stability below 270°C. This study provided a potential industrial application prospect of CA-PES membranes prepared in DMAc. PMID:27211301

  3. Adsorptive removal of phenolic compounds using cellulose acetate phthalate-alumina nanoparticle mixed matrix membrane.

    PubMed

    Mukherjee, Raka; De, Sirshendu

    2014-01-30

    Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute.

  4. Pervaporation of water and ethanol using a cellulose acetate butyrate membrane

    SciTech Connect

    Wu, W.S.; Lau, W.W.Y.; Rangaiah, G.P.; Sourirajan, S. . Dept. of Chemical Engineering)

    1993-10-15

    Okada and Matsuura's transport equations for pervaporation give rise to three fundamental parameters, namely, interfacial saturation vapor pressure P*, liquid transport parameter A/[delta], and vapor transport parameter B/[delta]. The effects of the chemical nature of the membrane material and the upstream operating pressures of 101.3 and 303.9 kPa on the above parameters were investigated from the pervaporation data at laboratory temperature (24 C) for water and ethanol using a cellulose acetate butyrate membrane. The results show that the P. values are essentially unaffected by the upstream pressure, and that they are generally higher than the literature values of saturation vapor pressure at 24 C. Further, the values for A/[delta] and B/[delta] tend to increase with increased upstream pressure for both systems studied. These results are discussed.

  5. Tuning aluminum spatial distribution in ZSM-5 membranes: a new strategy to fabricate high performance and stable zeolite membranes for dehydration of acetic acid.

    PubMed

    Yang, Jianhua; Li, Liangqing; Li, Wanze; Wang, Jinqu; Chen, Zan; Yin, Dehong; Lu, Jinming; Zhang, Yan; Guo, Hongchen

    2014-12-01

    A novel ZSM-5 membrane with a low Si/Al ratio and homogeneous aluminum spatial distribution was achieved from an organic template-free inorganic gel in the presence of both OH(-) and F(-) ions and the obtained ZSM-5 membrane exhibited excellent selectivity and high flux and stability for dehydration of acetic acid in a wide AcOH content range.

  6. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

    SciTech Connect

    Nurhadini, Arcana, I Made

    2015-09-30

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

  7. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO4 for lithium ion battery application

    NASA Astrophysics Data System (ADS)

    Nurhadini, Arcana, I. Made

    2015-09-01

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO4 membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10-4 S/cm was observed in SA/PEO/LiClO4 membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

  8. Application of denaturing gradient gel electrophoresis (DGGE) analysis to evaluate acetic acid bacteria in traditional balsamic vinegar.

    PubMed

    De Vero, Luciana; Gala, Elisabetta; Gullo, Maria; Solieri, Lisa; Landi, Sara; Giudici, Paolo

    2006-12-01

    Acetic acid bacteria (AAB) are fastidious micro-organisms to isolate and cultivate despite of the great number of growth media available. Moreover, conventional techniques used to study AAB populations are time consuming and not completely reliable. In this study, we tested the usefulness of the polymerase chain reaction-denaturing gradient gel electophoresis (PCR-DGGE) as a rapid and cost effective method for the screening of AAB in traditional balsamic vinegar (TBV). DGGE analysis was applied to 19 AAB strains isolated by agar plating from three different samples of TBV. DGGE was also used for the analysis of PCR products obtained from DNA extracted directly from the TBV samples. A tentative species identification was achieved comparing the PCR-DGGE patterns of the isolated strains and the TBV samples to those of 15 AAB reference strains. The results support that DGGE is functional to monitor vinegar's AAB population. PMID:16943087

  9. Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 2: Ultrafiltration and reverse-osmosis membranes

    SciTech Connect

    Kulkarni, S.; Krause, S. ); Wignall, G.D. . Solid State Div.)

    1994-11-07

    Pore structure in cellulose acetate ultrafiltration (UF) and reverse-osmosis (RO) membranes has been studied using small-angle neutron scattering. Scattering experiments were carried out on dry membranes as well as on membranes swollen with deuterated solvents (D[sub 2]O and CD[sub 3]OD). In addition, the RO membranes were studied both before and after annealing (a process of heating a membrane in a water bath at [approximately]75 C to improve its separation properties). The pore surface in UF membranes was found to be smooth and nonfractal, as evidenced by the fourth power law behavior at high Q. Values of average pore sizes obtained for dry and solvent swollen membranes agree well with pore sizes obtained by other methods. For cellulose acetate RO membranes in their dry state, the unannealed membrane appears to consist of two discrete pore size distributions in the intermediate and high Q region while the annealed membrane contains a much wider distribution of pore sizes. These results give a good account of the changes occurring in the structure of RO membranes as a result of annealing, and agree well with the prediction of other authors.

  10. Germination and adhesion of fungal conidia on polycarbonate membranes and on apple fruit exposed to mycoactive acetate esters.

    PubMed

    Filonow, Alexander B

    2003-02-01

    The adhesion and germination of conidia of nine fungal species were assessed on polycarbonate membranes or on the skin of apple fruit in sealed glass bottles injected or not injected with acetate esters. Adhesion was determined after dislodging conidia from surfaces using a sonication probe. Adhesion and germination of conidia of Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Penicillium citrinum, Penicillium claviforme, or Trichoderma sp. on membranes after 48 h were not increased in a 1.84 microg mL(-1) headspace of butyl acetate (BA), ethyl acetate, hexyl acetate, 2-methylbutyl acetate, pentyl acetate, or propyl acetate. Adhesion and germination of Botrytis cinerea, Penicillium expansum, and Penicillium roquefortii conidia were stimulated by all esters. Only conidia of B. cinerea and P. expansum exhibited increased adhesion and germination on the skin of apple fruit in bottles exposed to 0.92 microg mL(-1) of BA. Only conidia of B. cinerea and P. expansum produced decay in inoculated puncture wounds on fruit. Freshly made puncture wounds or 24-h-old puncture wounds in fruit were more adhesive than the unpunctured skin of fruit to conidia of B. cinerea or P. expansum. Fresh wounds were more adhesive to both fungi than 24-h-old puncture wounds. The skin and wounds of fruit were as adhesive to B. cinerea conidia as they were to P. expansum conidia. A 4-h exposure to 1.43 microg mL(-1) of BA increased adhesion of B. cinerea and P. expansum conidia in 24-h-old wounds. Results suggest that acetate-ester stimulation most likely is not a rare phenomenon in the fungi. For nutrient-dependent decay pathogens of apple fruit, acetate esters may be an alternative chemical cue used to maintain adhesion of conidia to wound surfaces. PMID:12718401

  11. A green approach to ethyl acetate: quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor.

    PubMed

    Zeng, Gaofeng; Chen, Tao; He, Lipeng; Pinnau, Ingo; Lai, Zhiping; Huang, Kuo-Wei

    2012-12-01

    Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters or hydrogen acceptors (see scheme). PMID:23136053

  12. Preparation and evaluation of water-in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using cellulose acetate membrane.

    PubMed

    Muhamad, Ida Idayu; Quin, Chang Hui; Selvakumaran, Suguna

    2016-04-01

    The purpose of this study was to investigate the preparation of formulated water- in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using a cellulose acetate membrane. The effect of selective membrane emulsification process parameters (concentration of the emulsifiers, number of passes of the emulsions through the membrane and storage temperature) on the properties and stability of the developed emulsions were also investigated. 1, 3, 6, 8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model ingredient for the encapsulation of bioactive substances. W/O emulsions with 7 wt% (weight percentage) PGPR displays homogeneous and very fine dispersions, with the median diameter at 0.640 μm. Meanwhile, emulsions prepared by membrane emulsification (fine W/O/W) showed the highest stability at Tween 80 concentrations of 0.5 wt.% (weight percentage). It concluded that at 7 wt.% (weight percentage) PGPR concentration and 0.5 wt.% (weight percentage) Tween 80 concentrations, the most uniform particles with minimum mean size of oil drops (9.926 μm) were obtained after four passes through the membrane. Thus, cellulose acetate membrane can be used for preparing a stable W/O/W emulsions by repeated premix ME due to low cost and relatively easy to handle. PMID:27413211

  13. Preparation and evaluation of water-in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using cellulose acetate membrane.

    PubMed

    Muhamad, Ida Idayu; Quin, Chang Hui; Selvakumaran, Suguna

    2016-04-01

    The purpose of this study was to investigate the preparation of formulated water- in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using a cellulose acetate membrane. The effect of selective membrane emulsification process parameters (concentration of the emulsifiers, number of passes of the emulsions through the membrane and storage temperature) on the properties and stability of the developed emulsions were also investigated. 1, 3, 6, 8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model ingredient for the encapsulation of bioactive substances. W/O emulsions with 7 wt% (weight percentage) PGPR displays homogeneous and very fine dispersions, with the median diameter at 0.640 μm. Meanwhile, emulsions prepared by membrane emulsification (fine W/O/W) showed the highest stability at Tween 80 concentrations of 0.5 wt.% (weight percentage). It concluded that at 7 wt.% (weight percentage) PGPR concentration and 0.5 wt.% (weight percentage) Tween 80 concentrations, the most uniform particles with minimum mean size of oil drops (9.926 μm) were obtained after four passes through the membrane. Thus, cellulose acetate membrane can be used for preparing a stable W/O/W emulsions by repeated premix ME due to low cost and relatively easy to handle.

  14. Fouling propensity and separation efficiency of epoxidated polyethersulfone incorporated cellulose acetate ultrafiltration membrane in the retention of proteins

    NASA Astrophysics Data System (ADS)

    Jayalakshmi, A.; Rajesh, S.; Mohan, D.

    2012-10-01

    Epoxidated polyethersulfone (EPES) incorporated cellulose acetate (CA) ultrafiltration membranes were prepared by diffusion induced precipitation technique in the absence and presence of pore former polyethyleneglycol-600. Effect of blend ratio on the compatibility, thermal stability, mechanical strength, hydrophilicity, morphology, pure water flux, protein adsorption resistance, protein separation efficiency and fouling propensity of the CA/EPES blend membranes was evaluated. Addition of EPES results in the formation of thin separating layer and spongy sub layer in CA/EPES blend membranes. The efficiency of these membranes in the separation of commercially important proteins such as bovine serum albumin, egg albumin, pepsin and trypsin was studied and found to be enhanced as compared to CA membranes. The fouling-resistant capability of the membranes was studied by bovine serum albumin as the model foulant and flux recovery ratio of the membranes were calculated. Attempts have been made to correlate the changes in membrane morphology with pure water flux, hydraulic resistance, thermal and mechanical stability, separation efficiency and antifouling property of the CA/EPES membranes. The optimal combination of CA and EPES, thus allows the preparation of high performance UF membranes which are sufficiently dense to retain proteins and at the same time give economically viable fluxes.

  15. Electrophoresis and isoelectric focusing of whole cell and membrane proteins from the extremely halophilic archaebacteria

    NASA Technical Reports Server (NTRS)

    Stan-Lotter, Helga; Lang, Frank J., Jr.; Hochstein, Lawrence I.

    1989-01-01

    The subunits from two purified halobacterial membrane enzymes (ATPase and nitrate reductase) behaved differently with respect to isoelectric focusing, silver staining and interaction with ampholytes. Differential behavior was also observed in whole cell proteins from Halobacterium saccharovorum regarding resolution in two-dimensional gels and silver staining. It is proposed that these differences reflect the existence of two classes of halobacterial proteins.

  16. Comparison of polycarbonate and cellulose acetate membrane filters for isolation of Campylobacter concisus from stool samples.

    PubMed

    Nielsen, Hans Linde; Engberg, Jørgen; Ejlertsen, Tove; Nielsen, Henrik

    2013-08-01

    One thousand seven hundred ninety-one diarrheic stool samples were cultivated for Campylobacter spp. We found a high prevalence of Campylobacter concisus with use of a polycarbonate filter (n = 114) compared to a cellulose acetate filter (n = 79) (P < .0001). The polycarbonate filter is superior to the commonly used cellulose acetate filter for detection of C. concisus.

  17. Fabrication of tethered carbon nanotubes in cellulose acetate/polyethylene glycol-400 composite membranes for reverse osmosis.

    PubMed

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Sarwar, Afsheen; Dilshad, Muhammad Rizwan; Shafeeq, Amir; Zahid Butt, Muhammad Taqi; Jamil, Tahir

    2015-11-01

    In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT.

  18. Free-Flow Electrophoresis of Plasma Membrane Vesicles Enriched by Two-Phase Partitioning Enhances the Quality of the Proteome from Arabidopsis Seedlings.

    PubMed

    de Michele, Roberto; McFarlane, Heather E; Parsons, Harriet T; Meents, Miranda J; Lao, Jeemeng; González Fernández-Niño, Susana M; Petzold, Christopher J; Frommer, Wolf B; Samuels, A Lacey; Heazlewood, Joshua L

    2016-03-01

    The plant plasma membrane is the interface between the cell and its environment undertaking a range of important functions related to transport, signaling, cell wall biosynthesis, and secretion. Multiple proteomic studies have attempted to capture the diversity of proteins in the plasma membrane using biochemical fractionation techniques. In this study, two-phase partitioning was combined with free-flow electrophoresis to produce a population of highly purified plasma membrane vesicles that were subsequently characterized by tandem mass spectroscopy. This combined high-quality plasma membrane isolation technique produced a reproducible proteomic library of over 1000 proteins with an extended dynamic range including plasma membrane-associated proteins. The approach enabled the detection of a number of putative plasma membrane proteins not previously identified by other studies, including peripheral membrane proteins. Utilizing multiple data sources, we developed a PM-confidence score to provide a value indicating association to the plasma membrane. This study highlights over 700 proteins that, while seemingly abundant at the plasma membrane, are mostly unstudied. To validate this data set, we selected 14 candidates and transiently localized 13 to the plasma membrane using a fluorescent tag. Given the importance of the plasma membrane, this data set provides a valuable tool to further investigate important proteins. The mass spectrometry data are available via ProteomeXchange, identifier PXD001795.

  19. Lateral electrophoresis and diffusion of Concanavalin A receptors in the membrane of embryonic muscle cell

    PubMed Central

    Poo, M. M.; Poo, W. J.; Lam, J. W.

    1978-01-01

    A uniform electric field of 10 V/cm applied across the surface of embryonic toad Xenopus muscle cells results in the asymmetric accumulation of concanavalin A (Con A) receptors toward one side of the cells within 10 min, as visualized by postfield fluorescent Con A labeling. This field produces an extracellular voltage difference of 20 mV across these 20-microns wide cells. The effect is reversible in two respects: (a) Additional exposure of the cell to the same field of opposite polarity for 10 min completely reverses the asymmetric accumulation to the other side of the cell. (b) Relaxation occurs after the removal of the field and results in complete recovery of the uniform distribution in 30 min. Both the accumulation and the recovery movements are independent of cell metabolism, and appear to be electrophoretic and diffusional in nature. The threshold field required to induce a detectable accumulation by the present method is between 1.0 and 1.5 V/cm (corresponding to a voltage difference of 2-3 mV across a 20-microns wide cell). The electrophoretic mobility of the most mobile population of nonliganded Con A receptors is estimated to be about 2 x 10(-3) microns/s per V/cm, while their diffusion coefficient is in the range of 4-7 x 10(-10) cm2/s. Extensive accumulation of the Con A receptors by an electric field results in the formation of immobile aggregates. The Con A receptors appear to consist of a heterogeneous population of membrane components different in their charge properties, mobility, and capability in forming aggregates. PMID:10605452

  20. Development of Low Cost Membranes (Ta, Nb & Cellulose Acetate) for H2/CO2 Separation in WGS Reactors

    SciTech Connect

    Seetala, Naidu; Siriwardane, Upali

    2011-12-15

    The main aim of this work is to synthesize low temperature bimetallic nanocatalysts for Water Gas Shift reaction (WGS) for hydrogen production from CO and steam mixture; and develop low-cost metal (Nb/Ta)/ceramic membranes for H2 separation and Cellulose Acetate membranes for CO2 separation. .

  1. Serum sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of patients with membranous nephropathy and focal and segmental glomerulosclerosis.

    PubMed

    Pant, Pragya; Singh, R G; Singh, Santosh K; Singh, Vijay P; Doley, Prodip K; Sivasankar, M

    2016-05-01

    Diagnosis of membranous nephropathy (MN) and focal and segmental glomerulo- sclerosis (FSGS) needs a renal biopsy, which is an invasive procedure with potentially serious complications. Proteomics may be applied for the development of a biomarker for these diseases which will obviate the need of biopsy. Serum sodium dodecyl sulfate-polyacrylamide gel electro-phoresis (SDS-PAGE) analysis gives an idea of the various proteins with different molecular weights (MWs) in a given sample. This study was conducted to analyze proteins with different MWs in patients with MN and FSGS and to compare the two groups with regard to their protein profile. This was a comparative, experimental study performed from June 2013 to July 2014 in the Department of Nephrology, Sir Sunderlal Hospital, Banaras Hindu University, Varanasi. Twenty-three histologically diagnosed cases of primary MN and 25 cases of FSGS were included in the study. Patients were categorized as having mild, moderate, and severe proteinuria with 24 h urinary protein levels of <4, 4- 8 and ≥8 g/24 h, respectively. SDS-PAGE analysis was performed by the method of Laemmli and revealed a significantly higher number of patients with FSGS (80%) having a protein corresponding to 29 kDa MW, than those with MN (39.1%) (P = 0.004). Protein of 5 kDa MW was present in a significantly higher number of patients with moderate (80%) and severe (100%) proteinuria than those with mild proteinuria (25%) (P <0.001). Thus, protein of MW 29 kDa may be a marker for FSGS and needs further characterization. Similarly, 5 kDa protein, present in patients with moderate and severe proteinuria, might be either contributing to or be a marker of severe illness.

  2. Removal of aqueous Hg(II) and Cr(VI) using phytic acid doped polyaniline/cellulose acetate composite membrane.

    PubMed

    Li, Renjie; Liu, Lifen; Yang, Fenglin

    2014-09-15

    Conductive composite membrane-phytic acid (PA) doped polyaniline (PANI)/cellulose acetate (CA) (PANI-PA/CA) was prepared in a simple and environmental-friendly method, in which aniline was blended with CA/PA solution and polymerized before the phase conversion. The resultant composite membranes were characterized by SEM, EDX, FTIR-ATR, BET and electrical resistance measurements. When used as adsorbent for Hg(II) and Cr(VI) ions, the prepared composite membrane exhibits excellent adsorption capability. The adsorption of Hg(II) and Cr(VI) follows a pseudo-second-order kinetic model and best fits the Langmuir isotherm model, with the maximum adsorption capacity reaching 280.11 and 94.34 mg g(-1), respectively. The heavy metal loaded composite membrane can be regenerated and reused after treatment with acid or alkali solution, making it a promising and practical adsorbent for Hg(II) and Cr(VI) removal. Tests with river water were also carried out, indicating good performance and application.

  3. ADSORPTION AND MEMBRANE SEPARATION MEASUREMENTS WITH MIXTURES OF ETHANOL, ACETIC ACID, AND WATER

    EPA Science Inventory

    Biomass fermentation produces ethanol and other renewable biofuels. Pervaporation using hydrophobic membranes is potentially a cost-effective means of removing biofuels from fermentation broths for small- to medium-scale applications. Silicalite-filled polydimethylsiloxane (PDMS)...

  4. Grafting of cellulose acetate with ionic liquids for biofuel purification by a membrane process: Influence of the cation.

    PubMed

    Hassan Hassan Abdellatif, Faten; Babin, Jérôme; Arnal-Herault, Carole; David, Laurent; Jonquieres, Anne

    2016-08-20

    A new strategy was developed for grafting ionic liquids (ILs) onto cellulose acetate in order to avoid IL extraction and improve its performance for ethyl tert-butyl ether (ETBE) biofuel purification by the pervaporation membrane process. This work extended the scope of IL-containing membranes to the challenging separation of organic liquid mixtures, in which these ILs were soluble. The ILs contained the same bromide anion and different cations with increasing polar feature. The membrane properties were strongly improved by IL grafting. Their analysis in terms of structure-property relationships revealed the influence of the IL content, chemical structure and chemical physical parameters α, β, π* in the Kamlet-Taft polarity scale. The ammonium IL led to the best normalized flux of 0.182kg/m(2)h for a reference thickness of 5μm, a permeate ethanol content of 100% and an outstanding infinite separation factor for the azeotropic mixture EtOH/ETBE at 50°C. PMID:27178937

  5. Membrane-directed effects of the plant hormones abscisic acid, indole-3-acetic acid and 2,4-dichlorophenoxyacetic acid.

    PubMed

    Schauf, C L; Bringle, B; Stillwell, W

    1987-03-30

    This study examines two ways plant hormones might influence membrane processes, effects on overall permeability and modifications of specific ion channels. Abscisic acid (ABA) and indole-3-acetic acid (IAA) greatly enhanced erythritol permeability in mixed egg lecithin bilayers. In single component dioleoylphosphatidylcholine bilayers ABA was less effective than IAA, while 2,4-dichlorophenoxyacetate (2,4-D) did not affect either system or alter their ABA response. In Myxicola axons ABA and IAA had no effect, while 2,4-D (10 uM) caused a depolarizing shift of voltage-dependent Na+ and K+ activation by 25 +/- 4 mV and 15 +/- 3 mV, consistent with internal negative surface charge changes of -0.002 e-/A2 and -0.0007 e-/A2. We conclude that both generalized and ion channel-directed effects may link plant hormones and intracellular regulation.

  6. Biomimetic accumulation of PAHs from soils by triolein-embedded cellulose acetate membranes (TECAMs) to estimate their bioavailability.

    PubMed

    Tao, Yuqiang; Zhang, Shuzhen; Wang, Zijian; Ke, Runhui; Shan, Xiao-quan; Christie, Peter

    2008-02-01

    A new passive sampling device (PSD), a triolein-embedded cellulose acetate membrane (TECAM), was used to biomimetically accumulate naphthalene, phenanthrene, pyrene and benzo[a]pyrene from ten spiked soils and a soil spiked with different concentrations of these polycyclic aromatic hydrocarbons (PAHs). TECAM exposure conditions were optimized. The quantities of PAHs accumulated by TECAMs were positively and linearly related to their concentrations in the soil. PAHs accumulated by TECAMs were negatively related to soil organic matter (SOM) and positively related to the dissolved organic carbon (DOC) according to the results obtained from ten spiked soils. Aging time (1-150 days) had a significant effect on accumulation of PAHs by TECAMs. A good linear relationship (R2=0.970-0.993) was observed between TECAM-accumulated PAHs and PAHs accumulated by earthworms (Eisenia andrei). The data indicate that TECAM represents a useful surrogate to estimate the bioavailability of PAHs and perhaps other hydrophobic organic contaminants (HOCs) in soils.

  7. Application of the triolein-embedded cellulose acetate membrane passive sampler for monitoring of polycyclic aromatic hydrocarbons in water.

    PubMed

    Tang, Jianfeng; He, Guiying; Li, Gang

    2014-01-01

    Triolein-embedded cellulose acetate membrane (TECAM) can be used as a passive sampler to measure hydrophobic organic contaminants in water. Uptake constant rates (k u ) for polycyclic aromatic hydrocarbons (PAHs) by TECAM sampling were measured under different hydrodynamic conditions. The measured k u values were modeled to enable the quantification of time weighed average (TWA) concentrations of PAHs in the field. An empirical relationship that enables the calculation of in situ k u values of chemicals using performance reference compounds (PRCs) was derived and its application was demonstrated in a field study. The results showed that freely dissolved concentrations of hydrophobic organic compounds (HOCs) can be accurately measured in the field using TECAM method based on empirical uptake models calibrated with PRCs.

  8. [State of the antioxidative activity of erythrocyte membranes in rats exposed to x-rays after administration of alpha-tocopherol acetate].

    PubMed

    Tsvetkova, T V; Tsokur, E V

    1988-01-01

    Injection of alpha-tocopherol acetate to albino mongrel rats potentiates antioxidant activity (AOA) that involves water-soluble factors of the antioxidant system in erythrocyte membranes. The activation of AOA by alpha-tocopherol takes place immediately after irradiation and drug injection and persists during the first 24 h following irradiation.

  9. Effect of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) upon membrane ionic exchanges in sea urchin eggs

    SciTech Connect

    Ciapa, B.; Payan, P. ); Allemand, D. )

    1989-12-01

    The effect of TPA (12-O-tetradecanoylphorbol-13-acetate) upon ionic exchanges was investigated in eggs of the sea urchin Arbacia lixula. Ouabain-sensitive {sup 86}Rb uptake and amiloride-sensitive {sup 24}Na influx were dramatically stimulated after TPA addition, indicating an enhancement of total ionic permeabilities. Stimulation by TPA of both Na{sup +}/H{sup +} and Na{sup +}/K{sup +} exchanges was canceled by amiloride, suggesting that activation of protein kinase C elicits, via Na{sup +}/H{sup +} activity, stimulation of the sodium pump. However, TPA did not stimulate sodium pump activity and Na{sup +}/H{sup +} exchange at the same rate as fertilization, probably because of an absence of calcium-dependent events. Further fertilization of TPA pretreated eggs triggered an enhancement of sodium pump activity when the TPA treatment duration did not exceed 10 minutes. It is suggested that TPA activates preexisting transporting mechanisms in plasma membranes of unfertilized eggs (Na{sup +} stat, pH stat).

  10. Analysis of electrophoresis performance

    NASA Technical Reports Server (NTRS)

    Roberts, G. O.

    1984-01-01

    The SAMPLE computer code models electrophoresis separation in a wide range of conditions. Results are included for steady three dimensional continuous flow electrophoresis (CFE), time dependent gel and acetate film experiments in one or two dimensions and isoelectric focusing in one dimension. The code evolves N two dimensional radical concentration distributions in time, or distance down a CFE chamber. For each time or distance increment, there are six stages, successively obtaining the pH distribution, the corresponding degrees of ionization for each radical, the conductivity, the electric field and current distribution, and the flux components in each direction for each separate radical. The final stage is to update the radical concentrations. The model formulation for ion motion in an electric field ignores activity effects, and is valid only for low concentrations; for larger concentrations the conductivity is, therefore, also invalid.

  11. Conjugation of silica nanoparticles with cellulose acetate/polyethylene glycol 300 membrane for reverse osmosis using MgSO4 solution.

    PubMed

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Jabeen, Faiza; Shafeeq, Amir; Ahmad, Adnan; Zahid Butt, Muhammad Taqi; Jacob, Karl I; Jamil, Tahir

    2016-01-20

    Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane. PMID:26572387

  12. Change in fluidity of brain endoplasmic reticulum membranes by oxygen free radicals: a protective effect of stobadine, alpha-tocopherol acetate, and butylated hydroxytoluene.

    PubMed

    Kaplán, P; Racay, P; Lehotský, J; Mézesová, V

    1995-07-01

    Effect of various oxygen free radical generating systems and an oxidant H2O2 on brain endoplasmic reticulum (ER) membrane fluidity was examined using fluorescent membrane probe 1,6-diphenyl-1,3,5-hexatriene, DPH. The relative potency of free radical generating systems to decrease membrane fluidity increased in this order: FeCl3-EDTA, FeSO4-EDTA, FeSO4-EDTA/hydrogen peroxide. Potency to decrease membrane fluidity correlated well with these systems' potencies to induce lipid peroxidation, as detected by conjugated diene formation. Treatment of ER membranes with H2O2 had no effect on fluidity or conjugated diene formation. Using the two most potent free radical generating systems, FeSO4-EDTA and FeSO4-EDTA/hydrogen peroxide, a protective effect of the novel antihypoxic and antiarrhytmic drug stobadine was tested. Stobadine and two well-known antioxidants, alpha-tocopherol acetate and butylated hydroxytoluene, demonstrated the ability to prevent free radical induced alterations in ER membrane fluidity. These results provide new evidence of stobadine's protective effect on membranes attacked by oxygen free radicals.

  13. Conjugation of silica nanoparticles with cellulose acetate/polyethylene glycol 300 membrane for reverse osmosis using MgSO4 solution.

    PubMed

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Jabeen, Faiza; Shafeeq, Amir; Ahmad, Adnan; Zahid Butt, Muhammad Taqi; Jacob, Karl I; Jamil, Tahir

    2016-01-20

    Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane.

  14. Cholesterol-rich membrane coatings for interaction studies in capillary electrophoresis: application to red blood cell lipid extracts.

    PubMed

    Lindén, Maria V; Holopainen, Juha M; Laukkanen, Antti; Riekkola, Marja-Liisa; Wiedmer, Susanne K

    2006-10-01

    The purpose was to develop a stable biological membrane coating for CE useful for membrane interaction studies. The effect of cholesterol (chol) on the stability of dipalmitoylphosphatidylcholine (DPPC) and sphingomyelin (SM) coatings was studied. In addition, a fused-silica capillary for CE was coated with human red blood cell (RBC) ghost lipids. Liposomes prepared of DPPC/SM with and without chol or RBC ghost lipids were flushed through the capillary and the stability of the coating was measured electrophoretically. Similar mixtures of DPPC/SM with and without chol were further studied by differential scanning calorimetry. The presence of phosphatidylcholine as a basic component in the coating solution of DPPC/SM/chol was found to be essential to achieve a good and stable coating. The results also confirmed the stability of coatings obtained with solutions of DPPC with 0-30 mol% of chol and SM in different ratios, which more closely resemble natural membranes. Finally, the electrophoretic measurements revealed that a stable coating is formed when capillaries are coated with liposomes of RBC ghost lipids. PMID:16983633

  15. Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air.

    PubMed

    Coelho, Lúcia H G; Melchert, Wanessa R; Rocha, Flavio R; Rocha, Fábio R P; Gutz, Ivano G R

    2010-11-15

    The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the μg m(-3) range) and their variations with sampling site and time. In this work, a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE), a quick separation technique that requires nothing more than some nanoliters of sample and, when combined with capacitively coupled contactless conductometric detection (C(4)D), is particularly favorable for ionic species that do not absorb in the UV-vis region, like the target analytes formaldehyde, formic acid, acetic acid and ammonium. The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry's constant such as formaldehyde and carboxylic acids, or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8.3 nL s(-1)), while the sample was aspirated through the annular gap of the concentric tubes at 2.5 mL s(-1). A second unit, in all similar to the CMDS, was operated as a capillary membrane diffusion emitter (CMDE), generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS. The fluids of the system were driven with inexpensive aquarium air pumps, and the collected samples were stored in vials cooled by a Peltier element. Complete protocols were developed for the analysis, in air, of NH(3), CH(3)COOH, HCOOH and, with a derivatization setup, CH(2)O, by associating the CMDS collection with the determination by CE-C(4)D. The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot's reaction. Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction, solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW). All

  16. STABILITY OF MFI ZEOLITE-FILLED PDMS MEMBRANES DURING PERVAPORATIVE ETHANOL RECOVERY FROM AQUEOUS MIXTURES CONTAINING ACETIC ACID

    EPA Science Inventory

    Pervaporation is a potential process for recovering bioethanol produced from biomass fermentation. Fermentation broths contain ethanol, water, and a variety of other compounds, often including carboxylic acids. The effects of acetic acid on long-term pervaporation of aqueous et...

  17. Electrophoresis technology

    NASA Technical Reports Server (NTRS)

    Snyder, R. S.

    1985-01-01

    A new high resolution apparatus designed for space was built as a laboratory prototype. Using a moving wall with a low zeta potential coating, the major sources of flow distortion for an electrophoretic sample stream are removed. Highly resolved fractions, however, will only be produced in space because of the sensitivity of this chamber to buoyancy-induced convection in the laboratory. The second and third flights of the McDonnell Douglas Astronautics Corporation continuous flow electrophoresis system carried samples developed at MSFC intended to evaluate the broad capabilities of free flow electrophoresis in a reduced gravity environment. Biological model materials, hemoglobin and polystyrene latex microspheres, were selected because of their past use as electrophoresis standards and as visible markers for fluid flow due to electroosmosis, spacecraft acceleration or other factors. The dependence of the separation resolution on the properties of the sample and its suspension solution was assessed.

  18. Gypsum (CaSO4·2H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis

    PubMed Central

    Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung

    2013-01-01

    We have examined the gypsum (CaSO4·2H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42° ± 14.85° after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 °C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062

  19. Simulating Electrophoresis.

    ERIC Educational Resources Information Center

    Moertel, Cheryl; Frutiger, Bruce

    1996-01-01

    Describes a DNA fingerprinting simulation that uses vegetable food coloring and plastic food containers instead of DNA and expensive gel electrophoresis chambers. Allows students to decipher unknown combinations of dyes in a method similar to that used to decipher samples of DNA in DNA fingerprint techniques. (JRH)

  20. Parallel characterization of anaerobic toluene- and ethylbenzene-degrading microbial consortia by PCR-denaturing gradient gel electrophoresis, RNA-DNA membrane hybridization, and DNA microarray technology

    NASA Technical Reports Server (NTRS)

    Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Said; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.

    2002-01-01

    A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis.

  1. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation.

    PubMed

    Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

    2014-01-01

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178

  2. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

    PubMed Central

    Casado-Coterillo, Clara; López-Guerrero, María del Mar; Irabien, Ángel

    2014-01-01

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178

  3. Analysis of diazinon pesticide using potentiometric biosensor based on enzyme immobilized cellulose acetate membrane in gold electrode

    NASA Astrophysics Data System (ADS)

    Mashuni; Ramadhan, L. O. A. N.; Jahiding, M.; Herniati

    2016-02-01

    Biosensor for analysis of diazinon pesticide using Potentiometric transducer has been developed. The basic element of this biosensor was a gold electrode modified with an immobilized acetylcholinesterase enzyme layer formed by entrapment with glutaraldehyde crosslinked-cellulose acetate. The aim of the research is to determine the composition of glutaraldehyde crosslinked-cellulose acetate in the gold electrode which provide optimum performance of biosensors of diazinon pesticide analysis on characterization include a range of working concentration, sensitivity, and detection limit. The results showed the composition of the cellulose acetate 15% and glutaraldehyde 25% that obtain optimum performance in the measurement of diazinon pesticide with a range of working concentration of 10-6 ppm to 1 ppm, the value of sensitivity 20.275 mV/decade and detection limit 10-6 ppm. The use of cellulose acetate provides highly sensitive devices allowing the efficient analysis of pesticides. The response time of electrode is on the measurement of pesticide diazinon with concentration variation of 10-6 ppm to 1 ppm with response time is about 5 minutes.

  4. Micromanipulation of adhesion of phorbol 12-myristate-13-acetate-stimulated T lymphocytes to planar membranes containing intercellular adhesion molecule-1.

    PubMed Central

    Tözeren, A; Mackie, L H; Lawrence, M B; Chan, P Y; Dustin, M L; Springer, T A

    1992-01-01

    This paper presents an analytical and experimental methodology to determine the physical strength of cell adhesion to a planar membrane containing one set of adhesion molecules. In particular, the T lymphocyte adhesion due to the interaction of the lymphocyte function associated molecule 1 on the surface of the cell, with its counter-receptor, intercellular adhesion molecule-1 (ICAM-1), on the planar membrane, was investigated. A micromanipulation method and mathematical analysis of cell deformation were used to determine (a) the area of conjugation between the cell and the substrate and (b) the energy that must be supplied to detach a unit area of the cell membrane from its substrate. T lymphocytes stimulated with phorbol 12-myristate-13-acetate (PMA) conjugated strongly with the planar membrane containing purified ICAM-1. The T lymphocytes attached to the planar membrane deviated occasionally from their round configuration by extending pseudopods but without changing the size of the contact area. These adherent cells were dramatically deformed and then detached when pulled away from the planar membrane by a micropipette. Detachment occurred by a gradual decrease in the radius of the contact area. The physical strength of adhesion between a PMA-stimulated T lymphocyte and a planar membrane containing 1,000 ICAM-1 molecules/micron 2 was comparable to the strength of adhesion between a cytotoxic T cell and its target cell. The comparison of the adhesive energy density, measured at constant cell shape, with the model predictions suggests that the physical strength of cell adhesion may increase significantly when the adhesion bonds in the contact area are immobilized by the actin cytoskeleton. Images FIGURE 2 FIGURE 4 FIGURE 5 FIGURE 8 FIGURE 9 PMID:1358239

  5. Membrane filtration of Sudan orange G on a cellulose acetate membrane filter for separation-preconcentration and spectrophotometric determination in water, chili powder, chili sauce and tomato sauce samples.

    PubMed

    ALOthman, Zeid A; Unsal, Yunus E; Habila, Mohamed; Shabaka, Azza; Tuzen, Mustafa; Soylak, Mustafa

    2012-08-01

    A simple membrane filtration procedure for separation-enrichment of Sudan orange G is presented. The method is based on the adsorption of Sudan orange G on a cellulose acetate filter and its elution from the membrane with 10 mL of ethanol. Sudan orange G in the eluent was determined by UV-visible spectrophotometry at 388 nm. The effect of analytical conditions, including pH, flow rates and eluent, sample volume, type of membrane for quantitative preconcentration and separation of Sudan orange G were examined. The influences of matrix components on Sudan orange G recoveries were studied. The preconcentration factor was 125. The detection limit was 4.9 μg L(-1). The relative standard deviation was 4.3%. The presented procedure was applied to chili powder, chili sauce, tomato sauce, powdered beverage and water samples. PMID:22617351

  6. Membrane filtration of Sudan orange G on a cellulose acetate membrane filter for separation-preconcentration and spectrophotometric determination in water, chili powder, chili sauce and tomato sauce samples.

    PubMed

    ALOthman, Zeid A; Unsal, Yunus E; Habila, Mohamed; Shabaka, Azza; Tuzen, Mustafa; Soylak, Mustafa

    2012-08-01

    A simple membrane filtration procedure for separation-enrichment of Sudan orange G is presented. The method is based on the adsorption of Sudan orange G on a cellulose acetate filter and its elution from the membrane with 10 mL of ethanol. Sudan orange G in the eluent was determined by UV-visible spectrophotometry at 388 nm. The effect of analytical conditions, including pH, flow rates and eluent, sample volume, type of membrane for quantitative preconcentration and separation of Sudan orange G were examined. The influences of matrix components on Sudan orange G recoveries were studied. The preconcentration factor was 125. The detection limit was 4.9 μg L(-1). The relative standard deviation was 4.3%. The presented procedure was applied to chili powder, chili sauce, tomato sauce, powdered beverage and water samples.

  7. Proteins induced during adaptation of Acetobacter aceti to high acetate concentrations.

    PubMed

    Steiner, P; Sauer, U

    2001-12-01

    As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of Acetobacter aceti by two-dimensional gel electrophoresis. Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation. Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress. Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps). Here we present first microsequence information on such Aaps from A. aceti. Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced.

  8. Proteins Induced during Adaptation of Acetobacter aceti to High Acetate Concentrations

    PubMed Central

    Steiner, Peter; Sauer, Uwe

    2001-01-01

    As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of Acetobacter aceti by two-dimensional gel electrophoresis. Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation. Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress. Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps). Here we present first microsequence information on such Aaps from A. aceti. Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced. PMID:11722895

  9. Capillary electrophoresis-based nanoscale assays for monitoring ecto-5'-nucleotidase activity and inhibition in preparations of recombinant enzyme and melanoma cell membranes.

    PubMed

    Iqbal, Jamshed; Jirovsky, David; Lee, Sang-Yong; Zimmermann, Herbert; Müller, Christa E

    2008-02-01

    Powerful capillary electrophoresis (CE) methods were developed for monitoring the reaction of ecto-5'-nucleotidase (ecto-5'-NT, CD73), a (patho)biochemically important enzyme that hydrolyzes nucleoside-5'-monophosphates to the corresponding nucleosides. The enzymatic reaction was performed either before injection into the capillary (method A) or directly within the capillary (method B). In method A, separation of substrates and products was achieved within 8 min using an eCAP fused-silica capillary (20 cm effective length, 75 microM i.d., UV detection at 260 nm), 40 mM sodium borate buffer (pH 9.1), normal polarity, and a constant voltage of 15 kV. In method B, the sandwich technique was applied; substrate dissolved in reaction buffer (10mM Hepes [pH 7.4], 2mM MgCl2, and 1mM CaCl2) was hydrodynamically injected into a fused-silica capillary (30 cm, 75 microM i.d.), followed by enzyme (recombinant rat ecto-5'-NT) and subsequent injection of substrate solution. The reaction was initiated by the application of 1 kV voltage for 1 min. The voltage was turned off for 1 min and again turned on at a constant voltage of 15 kV to elute products (nucleosides) within 4 min using borate buffer (40 mM, pH 9.1). Thus, assays could be performed within 6 min, including enzymatic reaction, separation, and quantification of the formed nucleoside. The CE methods were used for measuring enzyme kinetics and for assaying inhibitors and substrates. In addition, the online assay was successfully applied to melanoma cell membrane preparations natively expressing the human ecto-5'-NT.

  10. STABILITY OF MFI ZEOLITE-FILLED PDMS MEMBRANES DURING PERVAPORATIVE ETHANOL RECOVERY FROM AQUEOUS MIXTURES CONTAINING ACETIC ACID

    EPA Science Inventory

    Pervaporation is potentially a cost-effective means of recovering biofuels, such as ethanol, from biomass fermentation broths for small- to medium-scale applications (~2 - 20 million liters per year). Hydrophobic zeolite-filled polydimethylsiloxane (PDMS) membranes have been sho...

  11. Fluid flow electrophoresis in space

    NASA Technical Reports Server (NTRS)

    Griffin, R. N.

    1975-01-01

    Four areas relating to free-flow electrophoresis in space were investigated. The first was the degree of improvement over earthbound operations that might be expected. The second area of investigation covered the problems in developing a flowing buffer electrophoresis apparatus. The third area of investigation was the problem of testing on the ground equipment designed for use in space. The fourth area of investigation was the improvement to be expected in space for purification of biologicals. The results of some ground-based experiments are described. Other studies included cooling requirements in space, fluid sealing techniques, and measurement of voltage drop across membranes.

  12. rac p21 is involved in insulin-induced membrane ruffling and rho p21 is involved in hepatocyte growth factor- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced membrane ruffling in KB cells.

    PubMed Central

    Nishiyama, T; Sasaki, T; Takaishi, K; Kato, M; Yaku, H; Araki, K; Matsuura, Y; Takai, Y

    1994-01-01

    Insulin and hepatocyte growth factor (HGF) induced morphologically different membrane rufflings in KB cells. Insulin-induced membrane ruffling was inhibited by microinjection of rho GDI, an inhibitory GDP/GTP exchange regulator for both rho p21 and rac p21 small GTP-binding proteins, but not inhibited by microinjection of botulinum exoenzyme C3, known to selectively ADP-ribosylate rho p21 and to impair its function. This rho GDI action was prevented by comicroinjection with guanosine 5'-(3-O-thio)triphosphate (GTP gamma S)-bound rac1 p21. In contrast, HGF-induced membrane ruffling was inhibited by microinjection of rho GDI or C3. This rho GDI action was prevented by comicroinjection with GTP gamma S-bound rhoA p21, and this C3 action was prevented by comicroinjection with GTP gamma S-bound rhoAIle-41 p21, which is resistant to C3. Microinjection of either GTP gamma S-bound rac1 p21 or rhoA p21 alone induced membrane ruffling in the absence of the growth factors. The rac1 p21-induced membrane ruffling was morphologically similar to the insulin-induced kind, whereas rhoA p21-induced ruffling was apparently different from both the insulin- and HGF-induced kinds. Membrane ruffling was also induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C-activating phorbol ester, but not by Ca2+ ionophore or microinjection of a dominant active Ki-ras p21 mutant (Ki-rasVal-12 p21). The phorbol ester-induced membrane ruffling was morphologically similar to the rhoA p21-induced kind and inhibited by microinjection of rho GDI or C3. These results indicate that rac p21 and rho GDI are involved in insulin-induced membrane ruffling and that rho p21 and rho GDI are involved in HGF- and phorbol ester-induced membrane rufflings. Images PMID:8139548

  13. Immobilization of Aspergillus oryzae  β-Galactosidase on Cellulose Acetate-Polymethylmethacrylate Membrane and Its Application in Hydrolysis of Lactose from Milk and Whey

    PubMed Central

    Ansari, Shakeel Ahmed; Satar, Rukhsana; Kashif Zaidi, Syed; Ahmad, Abrar

    2014-01-01

    The present study demonstrates the immobilization of Aspergillus oryzae β-galactosidase on cellulose acetate-polymethylmethacrylate (CA-PMMA) membrane and its application in hydrolyzing lactose in dairy industries. The effect of physical and chemical denaturants like pH, temperature, product inhibition by galactose, storage stability, and reuse number of the enzyme immobilized on CA-PMMA membrane has been investigated. Lactose was hydrolyzed from milk and whey in batch reactors at 50°C by free and immobilized β-galactosidase (IβG). Optimum pH for the free and immobilized enzyme was found to be the same, that is, 4.5. However, IβG retained greater fractions of catalytic activity at lower and higher pH ranges. The temperature optimum for the immobilized enzyme was increased by 10°C. Moreover, Michaelis-Menten constant was increased for IβG as compared to the native one while maximum reaction rate was reduced for the immobilized enzyme. The preserved activity of free and immobilized enzyme was found to be 45% and 83%, respectively, after five weeks of storage at 4°C. Reusability of IβG was observed to be 86% even after fifth repeated use, thereby signifying its application in lactose hydrolysis (as shown in lab-scale batch reactors) in various dairy products including milk and whey. PMID:27350979

  14. Electricity generation coupled with wastewater treatment using a microbial fuel cell composed of a modified cathode with a ceramic membrane and cellulose acetate film.

    PubMed

    Seo, Ha Na; Lee, Woo Jin; Hwang, Tae Sik; Park, Doo Hyun

    2009-09-01

    A noncompartmented microbial fuel cell (NCMFC) composed of a Mn(IV)-carbon plate and a Fe(III)-carbon plate was used for electricity generation from organic wastewater without consumption of external energy. The Fe(III)-carbon plate, coated with a porous ceramic membrane and a semipermeable cellulose acetate film, was used as a cathode, which substituted for the catholyte and cathode. The Mn(IV)-carbon plate was used as an anode without a membrane or film coating. A solar cell connected to the NCMFC activated electricity generation and bacterial consumption of organic matter contained in the wastewater. More than 99 degrees of the organic matter was biochemically oxidized during wastewater flow through the four NCMFC units. A predominant bacterium isolated from the anode surface in both the conventional and the solar cell-linked NCMFC was found to be more than 99 degrees similar to a Mn(II)-oxidizing bacterium and Burkeholderia sp., based on 16S rDNA sequence analysis. The isolate reacted electrochemically with the Mn(IV)-modified anode and produced electricity in the NCMFC. After 90 days of incubation, a bacterial species that was enriched on the Mn(IV)-modified anode surface in all of the NCMFC units was found to be very similar to the initially isolated predominant species by comparing 16S rDNA sequences.

  15. Mechanism of gas permeation through polymer membranes. Part I. Pure gases. Comprehensive progress report. [Polybutadiene, poly(vinyl acetate), poly(methyl acrylate)

    SciTech Connect

    Stern, S.A.; Kulkarni, S.S.; Mauze, G.R.

    1982-07-01

    The objective of this study is to assess the validity of a free-volume model of gas permeation through nonporous polymer membranes. This model provides a formalism for the prediction of permeability coefficients for pure gaseous penetrants and their mixtures as a function of both pressure and temperature. Such information is of great importance for the development of new, energy-efficient membrane processes for the separation of gas mixtures. Diffusion and solubility coefficients for Ar, CO/sub 2/, CH/sub 4/, C/sub 2/H/sub 4/, C/sub 3/H/sub 8/, and SF/sub 6/ in polyethylene membranes and rods have been measured in the temperature range from 5/sup 0/ to 50/sup 0/C and at pressures up to 40 atm. under isothermal-isobaric conditions. It was found that the dependence of the diffusion and permeability coefficients on penetrant gas pressure and on temperature is satisfactorily represented by Fujita's free-volume model for the transport of small molecules in polymers and by its extension to gas permeation. The free-volume model of gas permeation relates permeability coefficients for gases in polymers to three thermodynamic variables, namely, temperature, pressure, and penetrant concentration, and to three characteristic parameters denoted A/sub d/, B/sub d/, and ..gamma... Semi-empirical correlations were developed for these parameters as a function of physicochemical properties of the penetrant and the polymer. These correlations were obeyed by the gas-polyethylene systems studied in the present work. A generalized correlation was found for B/sub d/ values of penetrants of various molecular sizes in polyethylene, polybutadiene, poly(vinyl acetate), poly(methyl acrylate), silicone rubber, and natural rubber.

  16. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    PubMed

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  17. Electrophoresis device

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H.; Snyder, R. S. (Inventor)

    1982-01-01

    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  18. Effect of K+ and Ca2+ on the indole-3-acetic acid- and fusicoccin-induced growth and membrane potential in maize coleoptile cells.

    PubMed

    Siemieniuk, Agnieszka; Karcz, Waldemar

    2015-06-30

    The role of potassium (K(+)) and calcium (Ca(2+)) in the regulation of plant growth and development is complex and needs a diverse range of physiological studies. Both elements are essential for satisfactory crop production. Here, the effects of K(+) and Ca(2+) ions on endogenous growth and growth in the presence of either indole-3-acetic acid (IAA) or fusicoccin (FC) were studied in maize (Zea mays) coleoptiles. Membrane potentials of coleoptile parenchymal cells, incubated in media containing IAA, FC and different concentrations of K(+) and Ca(2+), were also determined. Growth experiments have shown that in the absence of K(+) in the incubation medium, both endogenous and IAA- or FC-induced growth were significantly inhibited by 0.1 and 1 mM Ca(2+), respectively, while in the presence of 1 mM K(+) they were inhibited only by 1 mM Ca(2+). At 10 mM K(+), endogenous growth and growth induced by either IAA or FC did not depend on Ca(2+) concentration. TEA-Cl, a potassium channel blocker, added 1 h before IAA or FC, caused a reduction of growth by 59 or 45 %, respectively. In contrast to TEA-Cl, verapamil, the Ca(2+) channel blocker, did not affect IAA- and FC-induced growth. It was also found that in parenchymal cells of maize coleoptile segments, membrane potential (Em) was strongly affected by the medium K(+), independently of Ca(2+). However, lack of Ca(2+) in the incubation medium significantly reduced the IAA- and FC-induced membrane potential hyperpolarization. TEA-Cl applied to the control medium in the same way as in growth experiments caused Em hyperpolarization synergistic with hyperpolarization produced by IAA or FC. Verapamil did not change either the Em of parenchymal cells incubated in the control medium or the IAA- and FC-induced membrane hyperpolarization. The data presented here have been discussed considering the role of K(+) uptake channels in regulation of plant cell growth.

  19. Effect of K+ and Ca2+ on the indole-3-acetic acid- and fusicoccin-induced growth and membrane potential in maize coleoptile cells

    PubMed Central

    Siemieniuk, Agnieszka; Karcz, Waldemar

    2015-01-01

    The role of potassium (K+) and calcium (Ca2+) in the regulation of plant growth and development is complex and needs a diverse range of physiological studies. Both elements are essential for satisfactory crop production. Here, the effects of K+ and Ca2+ ions on endogenous growth and growth in the presence of either indole-3-acetic acid (IAA) or fusicoccin (FC) were studied in maize (Zea mays) coleoptiles. Membrane potentials of coleoptile parenchymal cells, incubated in media containing IAA, FC and different concentrations of K+ and Ca2+, were also determined. Growth experiments have shown that in the absence of K+ in the incubation medium, both endogenous and IAA- or FC-induced growth were significantly inhibited by 0.1 and 1 mM Ca2+, respectively, while in the presence of 1 mM K+ they were inhibited only by 1 mM Ca2+. At 10 mM K+, endogenous growth and growth induced by either IAA or FC did not depend on Ca2+ concentration. TEA-Cl, a potassium channel blocker, added 1 h before IAA or FC, caused a reduction of growth by 59 or 45 %, respectively. In contrast to TEA-Cl, verapamil, the Ca2+ channel blocker, did not affect IAA- and FC-induced growth. It was also found that in parenchymal cells of maize coleoptile segments, membrane potential (Em) was strongly affected by the medium K+, independently of Ca2+. However, lack of Ca2+ in the incubation medium significantly reduced the IAA- and FC-induced membrane potential hyperpolarization. TEA-Cl applied to the control medium in the same way as in growth experiments caused Em hyperpolarization synergistic with hyperpolarization produced by IAA or FC. Verapamil did not change either the Em of parenchymal cells incubated in the control medium or the IAA- and FC-induced membrane hyperpolarization. The data presented here have been discussed considering the role of K+ uptake channels in regulation of plant cell growth. PMID:26134122

  20. Electrophoresis. [in microgravity environment

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    Ground-based techniques for electrophoresis take account of the need either to circumvent the effects of gravity to prevent convection, or to use gravity for fluid stabilization through artificial density gradients. The microgravity environments of orbiting spacecraft provides a new alternative for electrophoresis by avoiding the need for either of these two approaches. The paper presents some theoretical considerations concerning electrophoresis, examines certain experimental techniques (zone and high density gel electrophoresis, isoelectric focusing and isotachophoresis), and examines the electrophoresis of living cells.

  1. Mesoxalaldehyde acetals

    SciTech Connect

    Gordeeva, G.N.; Kalashnikov, S.M.; Popov, Yu.N.; Kruglov, E.A.; Imashev, U.B.

    1987-11-10

    The treatment of methylglyoxal acetals by alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear mesoxalaldehyde acetals, whose structure was established by NMR spectroscopy and mass spectrometry. The major pathways for the decomposition of these molecules upon electron impact were established.

  2. Triolein embedded cellulose acetate membrane as a tool to evaluate sequestration of PAHs in lake sediment core at large temporal scale.

    PubMed

    Tao, Yuqiang; Xue, Bin; Yao, Shuchun; Deng, Jiancai; Gui, Zhifan

    2012-04-01

    Although numerous studies have addressed sequestration of hydrophobic organic compounds (HOCs) in laboratory, little attention has been paid to its evaluation method in field at large temporal scale. A biomimetic tool, triolein embedded cellulose acetate membrane (TECAM), was therefore tested to evaluate sequestration of six PAHs with various hydrophobicity in a well-dated sediment core sampled from Nanyi Lake, China. Properties of sediment organic matter (OM) varying with aging time dominated the sequestration of PAHs in the sediment core. TECAM-sediment accumulation factors (MSAFs) of the PAHs declined with aging time, and significantly correlated with the corresponding biota-sediment accumulation factors (BSAFs) for gastropod (Bellamya aeruginosa) simultaneously incubated in the same sediment slices. Sequestration rates of the PAHs in the sediment core evaluated by TECAM were much lower than those obtained from laboratory study. The relationship between relative availability for TECAM (MSAF(t)/MSAF(0)) and aging time followed the first order exponential decay model. MSAF(t)/MSAF(0) was well-related to the minor changes of the properties of OM varying with aging time. Compared with chemical extraction, sequestration reflected by TECAM was much closer to that by B. aeruginosa. In contrast to B. aeruginosa, TECAM could avoid metabolism and the influences from feeding and other behaviors of organisms, and it is much easier to deploy and ready in laboratory. Hence TECAM provides an effective and convenient way to study sequestration of PAHs and probably other HOCs in field at large temporal scale.

  3. Using linoleic acid embedded cellulose acetate membranes to in situ monitor polycyclic aromatic hydrocarbons in lakes and predict their bioavailability to submerged macrophytes.

    PubMed

    Tao, Yuqiang; Xue, Bin; Yao, Shuchun

    2015-05-19

    To date no passive sampler has been used to predict bioavailability of contaminants to macrophytes. Here a novel passive sampler, linoleic acid embedded cellulose acetate membrane (LAECAM), was developed and used to in situ measure the freely dissolved concentrations of ten polycyclic aromatic hydrocarbons in the sediment porewaters and the water columns of two lakes in both winter and summer and predict their bioavailability to the shoots of resident submerged macrophytes (Potamogeton malainus, Myriophyllum spicata, Najas minor All., and Vallisneria natans (Lour.) Hara). PAH sampling by LAECAMs could reach equilibrium within 21 days. The influence of temperature on LAECAM-water partition coefficients was 0.0008-0.0116 log units/°C. The method of LAECAM was comparable with the active sampling methods of liquid-liquid extraction combined with fDOC adjustment, centrifugation/solid-phase extraction (SPE), and filtration/SPE but had several advantages. After lipid normalization, concentrations of the PAHs in LAECAMs were not significantly different from those in the macrophytes. In contrast, concentrations of the PAHs in the triolein containing passive sampler (TECAM) deployed simultaneously with LAECAM were much higher. The results suggest that linoleic acid is more suitable than triolein as the model lipid for passive samplers to predict bioavailability of PAHs to submerged macrophytes.

  4. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1980-01-01

    The following aspects of kidney cell electrophoresis are discussed: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characterization of kidney cells.

  5. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1979-01-01

    A kidney cell electrophoresis technique is described in four parts: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characteristics of kidney cells.

  6. An Economical Electrophoresis Apparatus

    ERIC Educational Resources Information Center

    Andrews, I. M.

    1975-01-01

    Describes the production of an electrophoresis apparatus from commonly discarded articles. Outlines paper and gel electrophoresis and its application to the separation of amino acids and intestinal enzymes. (GS)

  7. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P. W.

    1985-01-01

    Tasks were undertaken in support of two objectives. They are: (1) to carry out electrophoresis experiments on cells in microgravity; and (2) assess the feasibility of using purified kidney cells from embryonic kidney cultures as a source of important cell products. Investigations were carried out in the following areas: (1) ground based electrophoresis technology; (2) cell culture technology; (3) electrophoresis of cells; (4) urokinase assay research; (5) zero-g electrophoresis; and (6) flow cytometry.

  8. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  9. Phenylmercuric acetate

    Integrated Risk Information System (IRIS)

    Phenylmercuric acetate ; CASRN 62 - 38 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  10. Vinyl acetate

    Integrated Risk Information System (IRIS)

    Vinyl acetate ; CASRN 108 - 05 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  11. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  12. Thallium acetate

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 30 , 2009 , the assessment summary for Thallium acetate is included in t

  13. Kidney Cell Electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1985-01-01

    Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated, ground support in the form of analytical cell electrophoresis and flow cytometry was provided and cells returned from space flight were analyzed. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. The protocol established and utilized is given.

  14. Automatic multiple applicator electrophoresis

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W.

    1977-01-01

    Easy-to-use, economical device permits electrophoresis on all known supporting media. System includes automatic multiple-sample applicator, sample holder, and electrophoresis apparatus. System has potential applicability to fields of taxonomy, immunology, and genetics. Apparatus is also used for electrofocusing.

  15. Electrophoresis of biological materials

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.

  16. Improved Electrophoresis Cell

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H.; Snyder, R. S.

    1982-01-01

    Several proposed modifications are expected to improve performance of a continous-flow electrophoresis cell. Changes would allow better control of buffer flow and would increase resolution by suppressing thermal gradients. Improved electrophoresis device would have high resolution and be easy to operate. Improvements would allow better flow control and heat dissipation.

  17. Electrophoresis for biological production

    NASA Technical Reports Server (NTRS)

    Mccreight, L. R.

    1977-01-01

    Preparative electrophoresis may provide a unique method for meeting ever more stringent purity requirements. Prolonged near zero gravity in space may permit the operation of preparative electrophoresis equipment with 100 times greater throughput than is currently available. Some experiments with influenza Virus Antigen, Erythropoietin and Antihemophaliac Factor, along with process and economic projections, are briefly reviewed.

  18. Preparative electrophoresis experiment design

    NASA Technical Reports Server (NTRS)

    Thiehler, A.

    1972-01-01

    A multifaceted study supporting the NASA programs to develop a space electrophoresis capability has been conducted. The study involved principally the technique of continuous free electrophoresis. It comprised a critical review of the art, study of new techniques for enhancing resolution and stability, and construction and initial testing of a high resolution cell. The effort resulted in a significant advance in free electrophoresis technique. It has provided also a much improved base for developments exploiting the added advantages of a zero-gravity environment.

  19. Binary Oscillatory Crossflow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Molloy, Richard F.; Gallagher, Christopher T.; Leighton, David T., Jr.

    1996-01-01

    We present preliminary results of our implementation of a novel electrophoresis separation technique: Binary Oscillatory Cross flow Electrophoresis (BOCE). The technique utilizes the interaction of two driving forces, an oscillatory electric field and an oscillatory shear flow, to create an active binary filter for the separation of charged species. Analytical and numerical studies have indicated that this technique is capable of separating proteins with electrophoretic mobilities differing by less than 10%. With an experimental device containing a separation chamber 20 cm long, 5 cm wide, and 1 mm thick, an order of magnitude increase in throughput over commercially available electrophoresis devices is theoretically possible.

  20. Serum globulin electrophoresis

    MedlinePlus

    ... may indicate: Acute infection Bone marrow cancer called multiple myeloma Chronic inflammatory disease (for example, rheumatoid arthritis and ... test Hemoglobin Hyperimmunization Immunoelectrophoresis - ... electrophoresis - serum Rheumatoid arthritis Systemic lupus erythematosus ...

  1. Electrophoresis operations in space

    NASA Technical Reports Server (NTRS)

    Richman, D. W.

    1982-01-01

    Application of electrophoresis in space processing is described. Spaceborne experiments in areas such as biological products and FDA approved drugs are discussed. These experiments will be carried on shuttle payloads.

  2. Biodegradation of cellulose acetate by Neisseria sicca.

    PubMed

    Sakai, K; Yamauchi, T; Nakasu, F; Ohe, T

    1996-10-01

    Bacteria capable of assimilating cellulose acetate, strains SB and SC, were isolated from soil on a medium containing cellulose acetate as a carbon source, and identified as Neisseria sicca. Both strains degraded cellulose acetate membrane filters (degree of substitution, DS, mixture of 2.8 and 2.0) and textiles (DS, 2.34) in a medium containing cellulose acetate (DS, 2.34) or its oligomer, but were not able to degrade these materials in a medium containing cellobiose octaacetate. Biodegradation of cellulose acetate (DS, 1.81 and 2.34) on the basis of biochemical oxygen demand reached 51 and 40% in the culture of N. sicca SB and 60 and 45% in the culture of N. sicca SC within 20 days. A decrease in the acetyl content of degraded cellulose acetate films and powder was confirmed by infrared and nuclear magnetic resonance analyses. After 10-day cultivation of N. sicca SB and SC, the number-average molecular weight of residual cellulose acetate decreased by 9 and 5%, respectively. Activities of enzymes that released acetic acid and produced reducing sugars from cellulose acetate were mainly present in the culture supernatant. Reactivity of enzymes for cellulose acetate (DS, 1.81) was higher than that for cellulose acetate (DS, 2.34).

  3. Recent advances in preparative electrophoresis

    NASA Technical Reports Server (NTRS)

    Mosher, Richard A.; Thormann, Wolfgang; Egen, Ned B.; Couasnon, Pascal; Sammons, David W.

    1987-01-01

    Various approaches for preparative electrophoresis, and three new instruments for preparative electrophoresis are discussed. Consideration is given to isoelectric focusing, isotachophoresis, and zone electrophoresis, three gel-based electrophoresis methods. The design, functions, and performance of the Elphor VaP 21 device of Hannig (1982), the shear-stabilized BIOSTREAM separator of Thompson (1983), and the recycling isoelectric focusing device are described.

  4. Using capillary electrophoresis for failure analysis

    SciTech Connect

    Kelly, R.G.; Scully, H.S.; Stoner, G.E. . Center for Electrochemical Science and Engineering)

    1993-07-01

    Capillary electrophoresis (CE), an advanced solution analysis technique, can be used for failure analysis of corroded components. It has high sensitivity (concentrations as low as parts-per-trillion) and can detect quantitatively a large number of ionic species. CE determined the vapor-phase attack by organic acids, mainly acetic acid, on an electrical equipment enclosure. These acids most likely originated from the seasoning of the oak pallets used to transport the manufactured items, accumulating inside the shrink-wrap film used to bind packages to the pallet.

  5. Formation of 4-keto-D-aldopentoses and 4-pentulosonates (4-keto-D-pentonates) with unidentified membrane-bound enzymes from acetic acid bacteria.

    PubMed

    Adachi, Osao; Hours, Roque A; Shinagawa, Emiko; Akakabe, Yoshihiko; Yakushi, Toshiharu; Matsushita, Kazunobu

    2011-01-01

    In our previous study, a new microbial reaction yielding 4-keto-D-arabonate from 2,5-diketo-D-gluconate was identified with Gluconacetobacter liquefaciens RCTMR 10. It appeared that decarboxylation and dehydrogenation took place together in the reaction. To analyze the nature of the reaction, investigations were done with the membrane fraction of the organism, and 4-keto-D-arabinose was confirmed as the direct precursor of 4-keto-D-arabonate. Two novel membrane-bound enzymes, 2,5-diketo-D-gluconate decarboxylase and 4-keto-D-aldopentose 1-dehydrogenase, were involved in the reaction. Alternatively, D-arabonate was oxidized to 4-keto-D-arabonate by another membrane-bound enzyme, D-arabonate 4-dehydrogenase. More directly, D-arabinose oxidation was examined with growing cells and with the membrane fraction of G. suboxydans IFO 12528. 4-Keto-D-arabinose, the same intermediate as that from 2,5-diketo-D-gluconate, was detected, and it was oxidized to 4-keto-D-arabonate. Likewise, D-ribose was oxidized to 4-keto-D-ribose and then it was oxidized to 4-keto-D-ribonate. In addition to 4-keto-D-aldopentose 1-dehydrogenase, the presence of a novel membrane-bound enzyme, D-aldopentose 4-dehydrogenase, was confirmed in the membrane fraction. The formation of 4-keto-D-aldopentoses and 4-keto-D-pentonates (4-pentulosonates) was finally confirmed as reaction products of four different novel membrane-bound enzymes.

  6. Formation of 4-keto-D-aldopentoses and 4-pentulosonates (4-keto-D-pentonates) with unidentified membrane-bound enzymes from acetic acid bacteria.

    PubMed

    Adachi, Osao; Hours, Roque A; Shinagawa, Emiko; Akakabe, Yoshihiko; Yakushi, Toshiharu; Matsushita, Kazunobu

    2011-01-01

    In our previous study, a new microbial reaction yielding 4-keto-D-arabonate from 2,5-diketo-D-gluconate was identified with Gluconacetobacter liquefaciens RCTMR 10. It appeared that decarboxylation and dehydrogenation took place together in the reaction. To analyze the nature of the reaction, investigations were done with the membrane fraction of the organism, and 4-keto-D-arabinose was confirmed as the direct precursor of 4-keto-D-arabonate. Two novel membrane-bound enzymes, 2,5-diketo-D-gluconate decarboxylase and 4-keto-D-aldopentose 1-dehydrogenase, were involved in the reaction. Alternatively, D-arabonate was oxidized to 4-keto-D-arabonate by another membrane-bound enzyme, D-arabonate 4-dehydrogenase. More directly, D-arabinose oxidation was examined with growing cells and with the membrane fraction of G. suboxydans IFO 12528. 4-Keto-D-arabinose, the same intermediate as that from 2,5-diketo-D-gluconate, was detected, and it was oxidized to 4-keto-D-arabonate. Likewise, D-ribose was oxidized to 4-keto-D-ribose and then it was oxidized to 4-keto-D-ribonate. In addition to 4-keto-D-aldopentose 1-dehydrogenase, the presence of a novel membrane-bound enzyme, D-aldopentose 4-dehydrogenase, was confirmed in the membrane fraction. The formation of 4-keto-D-aldopentoses and 4-keto-D-pentonates (4-pentulosonates) was finally confirmed as reaction products of four different novel membrane-bound enzymes. PMID:21897028

  7. Demonstration of calcium-dependent phospholipase A2 activity in membrane preparation of rabbit neutrophils. Absence of activation by fMet-Leu-Phe, phorbol 12-myristate 13-acetate and A-kinase.

    PubMed Central

    Matsumoto, T; Tao, W; Sha'afi, R I

    1988-01-01

    The presence of a phospholipase A2 (PLA2) activity in rabbit neutrophil membrane preparation that is able to release [1-14C]oleic acid from labelled Escherichia coli has been demonstrated. The activity is critically dependent on the free calcium concentration and marginally stimulated by GTP gamma S. More than 80% of maximal activity is reached at 10 microM-Ca2+. The chemotactic factor, fMet-Leu-Phe, does not stimulate the PLA2 activity in this membrane preparation. Pretreatment of the membrane preparation, under various experimental conditions, or intact cells, before isolation of the membrane with phorbol 12-myristate 13-acetate (PMA), does not affect PLA2 activity. Addition of the catalytic unit of cyclic AMP-dependent kinase to membrane preparation has no effect on PLA2 activity. Pretreatment of the intact neutrophil with dibutyryl-cAMP before isolation of the membrane produces a small but consistent increase in PLA2 activity. The activity of PLA2 in membrane isolated from cells treated with the protein kinase inhibitor 1-(5-isoquinolinesulphonyl)-2-methyl piperazine dihydrochloride (H-7) is significantly decreased. Furthermore, although the addition of PMA to intact rabbit neutrophils has no effect on the release of [3H]arachidonic acid from prelabelled cells, it potentiates significantly the release produced by the calcium ionophore A23187. This potentiation is not due to an inhibition of the acyltransferase activity. H-7 inhibits the basal release of arachidonic acid but does not inhibit the potentiation by PMA. These results suggest several points. (1) fMet-Leu-Phe does not stimulate PLA2 directly, and its ability to release arachidonic acid in intact neutrophils is mediated through its action on phospholipase C. (2) The potentiating effect of PMA on A23187-induced arachidonic acid release is most likely due to PMA affecting either the environment of PLA2 and/or altering the organization of membrane phospholipids in such a way as to increase their

  8. Electrophoresis in space.

    PubMed

    Bauer, J; Hymer, W C; Morrison, D R; Kobayashi, H; Seaman, G V; Weber, G

    1999-01-01

    Programs for free flow electrophoresis in microgravity over the past 25 years are reviewed. Several studies accomplished during 20 spaceflight missions have demonstrated that sample throughput is significantly higher in microgravity than on the ground. Some studies have shown that resolution is also increased. However, many cell separation trials have fallen victim to difficulties associated with experimenting in the microgravity environment such as microbial contamination, air bubbles in electrophoresis chambers, and inadequate facilities for maintaining cells before and after separation. Recent studies suggest that the charge density of cells at their surface may also be modified in microgravity. If this result is confirmed, a further cellular mechanism of "sensing" the low gravity environment will have been found. Several free fluid electrophoresis devices are now available. Most have been tried at least once in microgravity. Newer units not yet tested in spaceflight have been designed to accommodate problems associated with space processing. The USCEPS device and the Japanese FFEU device are specifically designed for sterile operations, whereas the Octopus device is designed to reduce electroosmotic and electrohydrodynamic effects, which become dominant and detrimental in microgravity. Some of these devices will also separate proteins by zone electrophoresis, isotachophoresis, or isoelectric focusing in a single unit. Separation experiments with standard test particles are useful and necessary for testing and optimizing new space hardware. A cohesive free fluid electrophoresis program in the future will obviously require (1) flight opportunities and funding, (2) identification of suitable cellular and macromolecular candidate samples, and (3) provision of a proper interface of electrophoresis processing equipment with biotechnological facilities--equipment like bioreactors and protein crystal growth chambers. The authors feel that such capabilities will lead to

  9. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    PubMed

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress. PMID:26416641

  10. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    PubMed

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress.

  11. DNA ELECTROPHORESIS AT SURFACES

    SciTech Connect

    RAFAILOVICH, MIRIAM; SOKOLOV, JONATHAN; GERSAPPE, DILIP

    2003-09-01

    During this year we performed two major projects: I. We developed a detailed theoretical model which complements our experiments on surface DNA electrophoresis. We found that it was possible to enhance the separation of DNA chains by imposing a chemical nanoscale pattern on the surface. This approach utilized the surface interaction effect of the DNA chains with the substrate and is a refinement to our previous method in which DNA chains were separated on homogeneous flat surfaces. By introducing the nano-patterns on the surface, the conformational changes of DNA chains of different lengths can be amplified, which results in the different friction strengths with the substrate surface. Our results also show that, when compared to the DNA electrophoresis performed on homogeneous flat surfaces, nanopatterned surfaces offer a larger window in choosing different surface interactions to achieve separation. II. In collaboration with a large international manufacturer of skin care products we also embarked on a project involving photo toxicity of titanium dioxide nanoparticles, which are a key ingredient in sunscreen and cosmetic lotions. The results clearly implicated the nanoparticles in catalyzing damage to chromosomal DNA. We then used this knowledge to develop a polymer/anti-oxidant coating which prevented the photocatalytic reaction on DNA while still retaining the UV absorptive properties of the nanoparticles. The standard gel electrophoresis was not sufficient in determining the extent of the DNA damage. The conclusions of this study were based predominantly on analysis obtained with the surface electrophoresis method.

  12. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii

    PubMed Central

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A.; Olsson, Lisbeth

    2015-01-01

    ABSTRACT Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic‐acid‐tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo­lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin‐treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress. Biotechnol. Bioeng. 2016;113: 744–753. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:26416641

  13. Happy bicentennial, electrophoresis!

    PubMed

    Righetti, Pier Giorgio

    2009-12-01

    A short survey of electrophoresis and a celebration of its bicentennial, with some remarkable mementos and a list of books that shaped the field. Where one also learns of a secret production plant with a huge-scale electrophoretic apparatus for skimming of latex from Hevea brasiliensis and keeping the wheels of the Ally Army running during World War II. And of cyber (mammoth) 2D gels of 1.5 x 1 m in size accommodating >12,000 spots. PMID:19938305

  14. Capillary zone electrophoresis

    SciTech Connect

    Jorgenson, J.W.; Lukacs, K.D.

    1983-10-21

    Zone electrophoresis in capillaries is a technique complementary to electrophoresis in supporting media, and each approach has its own particular advantages. Efficient heat transfer from small-diameter capillaries permits use of unusually high voltages, resulting in both high resolution and rapid analysis. Capillaries also seem well suited for automation. Our present electromigration injection technique is relatively straightforward and should be simple to automate. Capillaries are reusable, which is an advantage over gels. On-line electronic detection permits good quantification, further enhancing possibilities for fully automatic operation. The greatest obstacle to further development and utilization of capillaries is the requirement of extremely sensitive detectors, and more types of detectors with higher sensitivity are greatly needed. A better understanding of capillary surface modification will also be important, both for improved capillary surface deactivation and for better control over electroosmotic flow. Capillaries should provide an ideal system in which to explore nonaqueous separation media. The prospects for nonaqueous media in electrophoresis are similar to those in electrochemistry, and capillaries should prove an excellent system in which to begin their study. 18 refs., 8 figs.

  15. Preparative electrophoresis for space

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1987-01-01

    A premise of continuous flow electrophoresis is that removal of buoyancy-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chambers are used, distortion of the injected sample stream due to electrohydrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field have not been considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.

  16. Preparative electrophoresis for space

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1988-01-01

    A premise of continuous flow electrophoresis is that removal of buoyance-induced thermal convection caused by axial and lateral temperature gradients results in ideal performance of these instruments in space. Although these gravity dependent phenomena disturb the rectilinear flow in the separation chamber when high voltage gradients or thick chamber are used, distortion of the injected sample stream due to electrodynamic effects cause major broadening of the separated bands. The electrophoresis separation process is simple, however flow local to the sample filament produced by the applied electric field were not considered. These electrohydrodynamic flows distort the sample stream and limit the separation. Also, electroosmosis and viscous flow combine to further distort the process. A moving wall concept is being proposed for space which will eliminate and control the disturbances. The moving wall entrains the fluid to move as a rigid body and produces a constant residence time for all samples distributed across the chamber thickness. The moving wall electrophoresis chamber can only be operated in space because there is no viscous flow in the chamber to stabilize against thermal convection.

  17. Electrophoresis experiments in microgravity

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.; Rhodes, Percy H.

    1991-01-01

    The use of the microgravity environment to separate and purify biological cells and proteins has been a major activity since the beginning of the NASA Microgravity Science and Applications program. Purified populations of cells are needed for research, transplantation and analysis of specific cell constituents. Protein purification is a necessary step in research areas such as genetic engineering where the new protein has to be separated from the variety of other proteins synthesized from the microorganism. Sufficient data are available from the results of past electrophoresis experiments in space to show that these experiments were designed with incomplete knowledge of the fluid dynamics of the process including electrohydrodynamics. However, electrophoresis is still an important separation tool in the laboratory and thermal convection does limit its performance. Thus, there is a justification for electrophoresis but the emphasis of future space experiments must be directed toward basic research with model experiments to understand the microgravity environment and fluid analysis to test the basic principles of the process.

  18. Automatic multiple-sample applicator and electrophoresis apparatus

    NASA Technical Reports Server (NTRS)

    Grunbaum, B. W. (Inventor)

    1977-01-01

    An apparatus for performing electrophoresis and a multiple-sample applicator is described. Electrophoresis is a physical process in which electrically charged molecules and colloidal particles, upon the application of a dc current, migrate along a gel or a membrane that is wetted with an electrolyte. A multiple-sample applicator is provided which coacts with a novel tank cover to permit an operator either to depress a single button, thus causing multiple samples to be deposited on the gel or on the membrane simultaneously, or to depress one or more sample applicators separately by means of a separate button for each applicator.

  19. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, E.S.; Li, Q.; Lu, X.

    1998-04-21

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  20. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, E.S.; Chang, H.T.; Fung, E.N.; Li, Q.; Lu, X.

    1996-12-10

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  1. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S.; Li, Qingbo; Lu, Xiandan

    1998-04-21

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.

  2. Multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S.; Chang, Huan-Tsang; Fung, Eliza N.; Li, Qingbo; Lu, Xiandan

    1996-12-10

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.

  3. Multiplexed Western Blotting Using Microchip Electrophoresis.

    PubMed

    Jin, Shi; Furtaw, Michael D; Chen, Huaxian; Lamb, Don T; Ferguson, Stephen A; Arvin, Natalie E; Dawod, Mohamed; Kennedy, Robert T

    2016-07-01

    Western blotting is a commonly used protein assay that combines the selectivity of electrophoretic separation and immunoassay. The technique is limited by long time, manual operation with mediocre reproducibility, and large sample consumption, typically 10-20 μg per assay. Western blots are also usually used to measure only one protein per assay with an additional housekeeping protein for normalization. Measurement of multiple proteins is possible; however, it requires stripping membranes of antibody and then reprobing with a second antibody. Miniaturized alternatives to Western blot based on microfluidic or capillary electrophoresis have been developed that enable higher-throughput, automation, and greater mass sensitivity. In one approach, proteins are separated by electrophoresis on a microchip that is dragged along a polyvinylidene fluoride membrane so that as proteins exit the chip they are captured on the membrane for immunoassay. In this work, we improve this method to allow multiplexed protein detection. Multiple injections made from the same sample can be deposited in separate tracks so that each is probed with a different antibody. To further enhance multiplexing capability, the electrophoresis channel dimensions were optimized for resolution while keeping separation and blotting times to less than 8 min. Using a 15 μm deep × 50 μm wide × 8.6 cm long channel, it is possible to achieve baseline resolution of proteins that differ by 5% in molecular weight, e.g., ERK1 (44 kDa) from ERK2 (42 kDa). This resolution allows similar proteins detected by cross-reactive antibodies in a single track. We demonstrate detection of 11 proteins from 9 injections from a single Jurkat cell lysate sample consisting of 400 ng of total protein using this procedure. Thus, multiplexed Western blots are possible without cumbersome stripping and reprobing steps. PMID:27270033

  4. Apparatus for electrophoresis separation

    DOEpatents

    Anderson, Norman L.

    1978-01-01

    An apparatus is disclosed for simultaneously performing electrophoresis separations on a plurality of slab gels containing samples of protein, protein subunits or nucleic acids. A reservoir of buffer solution is divided into three compartments by two parallel partitions having vertical slots spaced along their length. A sheet of flexible, electrically insulative material is attached to each partition and is provided with vertical slits aligned with the slots. Slab-gel holders are received within the slots with the flexible material folded outwardly as flaps from the slits to overlay portions of the holder surfaces and thereby act as electrical and liquid seals. An elongated, spaghetti-like gel containing a sample of specimen that was previously separated by isoelectric focusing techniques is vertically positioned along a marginal edge portion of the slab gel. On application of an electrical potential between the two outer chambers of buffer solution, a second dimensional electrophoresis separation in accordance with molecular weight occurs as the specimen molecules migrate across the slab gel.

  5. Capillary Electrophoresis in Metabolomics.

    PubMed

    Maier, Tanja Verena; Schmitt-Kopplin, Philippe

    2016-01-01

    Metabolomics is an analytical toolbox to describe (all) low-molecular-weight compounds in a biological system, as cells, tissues, urine, and feces, as well as in serum and plasma. To analyze such complex biological samples, high requirements on the analytical technique are needed due to the high variation in compound physico-chemistry (cholesterol derivatives, amino acids, fatty acids as SCFA, MCFA, or LCFA, or pathway-related metabolites belonging to each individual organism) and concentration dynamic range. All main separation techniques (LC-MS, GC-MS) are applied in routine to metabolomics hyphenated or not to mass spectrometry, and capillary electrophoresis is a powerful high-resolving technique but still underused in this field of complex samples. Metabolomics can be performed in the non-targeted way to gain an overview on metabolite profiles in biological samples. Targeted metabolomics is applied to analyze quantitatively pre-selected metabolites. This chapter reviews the use of capillary electrophoresis in the field of metabolomics and exemplifies solutions in metabolite profiling and analysis in urine and plasma. PMID:27645748

  6. Possibility of Microchip Electrophoresis for Biological Application

    NASA Astrophysics Data System (ADS)

    Kataoka, Masatoshi; Kido, Jun-Ichi; Shinohara, Yasuo

    Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. Nucleic acid fragments are separated by capillary electrophoresis in a chip with microfabricated channels, with automated detection as well as on-line data evaluation. Microfabricated devices are forecast to be fundamental to the postgenome era, especially in the field of genetics and medicine. However, although there are many reports of the use of these instruments to evaluate standard DNA, DNA ladders, PCR products, and commercially available plasmid digests, little information is available their use with biological material. In this report, we showed the accuracy of sizing and quantification of endonuclease-digested plasmid DNA. We also showed the feasibility of on-microchip endonuclease treatment of plasmid DNA and sequential analysis as an additional application for DNA analysis. Furthermore, to evaluate the possibility of microchip electrophoresis for biological application, the results of the examination of blood sugar in human plasma and mitochondrial membrane potential were shown.

  7. Fragrance material review on piperonyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of piperonyl acetate when used as a fragrance ingredient is presented. Piperonyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for piperonyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, toxicokinetics, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  8. Fragrance material review on 2-phenylpropyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-phenylpropyl acetate when used as a fragrance ingredient is presented. 2-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  9. Analysis of Protein Oligomerization by Electrophoresis.

    PubMed

    Cubillos-Rojas, Monica; Schneider, Taiane; Sánchez-Tena, Susana; Bartrons, Ramon; Ventura, Francesc; Rosa, Jose Luis

    2016-01-01

    A polypeptide chain can interact with other polypeptide chains and form stable and functional complexes called "oligomers." Frequently, biochemical analysis of these complexes is made difficult by their great size. Traditionally, size exclusion chromatography, immunoaffinity chromatography, or immunoprecipitation techniques have been used to isolate oligomers. Components of these oligomers are then further separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and identified by immunoblotting with specific antibodies. Although they are sensitive, these techniques are not easy to perform and reproduce. The use of Tris-acetate polyacrylamide gradient gel electrophoresis allows the simultaneous analysis of proteins in the mass range of 10-500 kDa. We have used this characteristic together with cross-linking reagents to analyze the oligomerization of endogenous proteins with a single electrophoretic gel. We demonstrate how the oligomerization of p53, the pyruvate kinase isoform M2, or the heat shock protein 27 can be studied with this system. We also show how this system is useful for studying the oligomerization of large proteins such as clathrin heavy chain or the tuberous sclerosis complex. Oligomerization analysis is dependent on the cross-linker used and its concentration. All of these features make this system a very helpful tool for the analysis of protein oligomerization. PMID:27613048

  10. Derivatization in Capillary Electrophoresis.

    PubMed

    Marina, M Luisa; Castro-Puyana, María

    2016-01-01

    Capillary electrophoresis is a well-established separation technique in analytical research laboratories worldwide. Its interesting advantages make CE an efficient and potent alternative to other chromatographic techniques. However, it is also recognized that its main drawback is the relatively poor sensitivity when using optical detection. One way to overcome this limitation is to perform a derivatization reaction which is intended to provide the analyte more suitable analytical characteristics enabling a high sensitive detection. Based on the analytical step where the CE derivatization takes place, it can be classified as precapillary (before separation), in-capillary (during separation), or postcapillary (after separation). This chapter describes the application of four different derivatization protocols (in-capillary and precapillary modes) to carry out the achiral and chiral analysis of different compounds in food and biological samples with three different detection modes (UV, LIF, and MS). PMID:27645730

  11. Electrophoresis experiment for space

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; Micale, F. J.

    1976-01-01

    The Apollo 16 electrophoresis experiment was analyzed, demonstrating that the separation of the two different-size monodisperse latexes did indeed take place, but that the separation was obscured by the pronounced electroosmotic flow of the liquid medium. The results of this experiment, however, were dramatic since it is impossible to carry out a similar separation on earth. It can be stated unequivocally from this experiment that any electrophoretic separation will be enhanced under microgravity conditions. The only question is the degree of this enhancement, which can be expected to vary from one experimental technique to another. The low-electroosmotic-mobility coating (Z6040-MC) developed under this program was found to be suitable for a free-fluid electrophoretic separation such as the experiment designed for the ASTP flight. The problem with this coating, however, is that its permanency is limited because of the slow desorption of the methylcellulose from the coated surface.

  12. Static continuous electrophoresis device

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H. (Inventor)

    1982-01-01

    An apparatus is disclosed for carrying out a moving wall type electrophoresis process for separation of cellular particles. The apparatus includes a water-tight housing containing an electrolytic buffer solution. A separation chamber in the housing is defined by spaced opposed moving walls and spaced opposed side walls. Substrate assemblies, which support the moving wall include vacuum ports for positively sealing the moving walls against the substrate walls. Several suction conduits communicate with the suction ports and are arranged in the form of valleys in a grid plate. The raised land portion of the grid plat supports the substrate walls against deformation inwardly under suction. A cooling chamber is carried on the back side of plate. The apparatus also has tensioner means including roller and adjustment screws for maintaining the belts in position and a drive arrangement including an electric motor with a gear affixed to its output shaft. Electrode assemblies are disposed to provide the required electric field.

  13. Kidney cell electrophoresis, continuing task

    NASA Technical Reports Server (NTRS)

    Todd, P. W.

    1985-01-01

    Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated to provide ground support in the form of analytical cell electrophoresis and flow cytometry. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. Cells were prepared in suspension prior to flight in electrophoresis buffer and 10% calf serum. Electrophoretic separation proceeded in electrophoresis buffer without serum in the Continuous Flow Electrophoretic Separator, and fractions were collected into sample bags containing culture medium and concentrated serum. Fractions that yielded enough progeny cells were analyzed for morphology and electrophoretic mobility distributions. It is noted that the lowest mobility fraction studied produced higher mobility progeny while the other fractions produced progeny cells with mobilities related to the fractions from which they were collected.

  14. Electrophoresis demonstration on Apollo 16

    NASA Technical Reports Server (NTRS)

    Snyder, R. S.

    1972-01-01

    Free fluid electrophoresis, a process used to separate particulate species according to surface charge, size, or shape was suggested as a promising technique to utilize the near zero gravity condition of space. Fluid electrophoresis on earth is disturbed by gravity-induced thermal convection and sedimentation. An apparatus was developed to demonstrate the principle and possible problems of electrophoresis on Apollo 14 and the separation boundary between red and blue dye was photographed in space. The basic operating elements of the Apollo 14 unit were used for a second flight demonstration on Apollo 16. Polystyrene latex particles of two different sizes were used to simulate the electrophoresis of large biological particles. The particle bands in space were extremely stable compared to ground operation because convection in the fluid was negligible. Electrophoresis of the polystyrene latex particle groups according to size was accomplished although electro-osmosis in the flight apparatus prevented the clear separation of two particle bands.

  15. Binary Oscillatory Crossflow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Molloy, Richard F.; Gallagher, Christopher T.; Leighton, David T., Jr.

    1997-01-01

    Electrophoresis has long been recognized as an effective analytic technique for the separation of proteins and other charged species, however attempts at scaling up to accommodate commercial volumes have met with limited success. In this report we describe a novel electrophoretic separation technique - Binary Oscillatory Crossflow Electrophoresis (BOCE). Numerical simulations indicate that the technique has the potential for preparative scale throughputs with high resolution, while simultaneously avoiding many problems common to conventional electrophoresis. The technique utilizes the interaction of an oscillatory electric field and a transverse oscillatory shear flow to create an active binary filter for the separation of charged protein species. An oscillatory electric field is applied across the narrow gap of a rectangular channel inducing a periodic motion of charged protein species. The amplitude of this motion depends on the dimensionless electrophoretic mobility, alpha = E(sub o)mu/(omega)d, where E(sub o) is the amplitude of the electric field oscillations, mu is the dimensional mobility, omega is the angular frequency of oscillation and d is the channel gap width. An oscillatory shear flow is induced along the length of the channel resulting in the separation of species with different mobilities. We present a model that predicts the oscillatory behavior of charged species and allows estimation of both the magnitude of the induced convective velocity and the effective diffusivity as a function of a in infinitely long channels. Numerical results indicate that in addition to the mobility dependence, the steady state behavior of solute species may be strongly affected by oscillating fluid into and out of the active electric field region at the ends of the cell. The effect is most pronounced using time dependent shear flows of the same frequency (cos((omega)t)) flow mode) as the electric field oscillations. Under such conditions, experiments indicate that

  16. Surface Charge Measurement of SonoVue, Definity and Optison: A Comparison of Laser Doppler Electrophoresis and Micro-Electrophoresis.

    PubMed

    Ja'afar, Fairuzeta; Leow, Chee Hau; Garbin, Valeria; Sennoga, Charles A; Tang, Meng-Xing; Seddon, John M

    2015-11-01

    Microbubble (MB) contrast-enhanced ultrasonography is a promising tool for targeted molecular imaging. It is important to determine the MB surface charge accurately as it affects the MB interactions with cell membranes. In this article, we report the surface charge measurement of SonoVue, Definity and Optison. We compare the performance of the widely used laser Doppler electrophoresis with an in-house micro-electrophoresis system. By optically tracking MB electrophoretic velocity in a microchannel, we determined the zeta potentials of MB samples. Using micro-electrophoresis, we obtained zeta potential values for SonoVue, Definity and Optison of -28.3, -4.2 and -9.5 mV, with relative standard deviations of 5%, 48% and 8%, respectively. In comparison, laser Doppler electrophoresis gave -8.7, +0.7 and +15.8 mV with relative standard deviations of 330%, 29,000% and 130%, respectively. We found that the reliability of laser Doppler electrophoresis is compromised by MB buoyancy. Micro-electrophoresis determined zeta potential values with a 10-fold improvement in relative standard deviation.

  17. A unique enzyme of acetic acid bacteria, PQQ-dependent alcohol dehydrogenase, is also present in Frateuria aurantia.

    PubMed

    Trček, Janja; Matsushita, Kazunobu

    2013-08-01

    A membrane-bound, pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) was purified from Frateuria aurantia LMG 1558(T). Although F. aurantia belongs to a group of γ-Proteobacteria, the characteristics of its PQQ-ADH were similar to the enzyme characteristics of the typical high-acetic acid-resistant bacterium Gluconacetobacter europaeus from the group of α-Proteobacteria. The PQQ-dependent ADH was solubilized from the membranes and purified after anionic, cationic, and affinity chromatography with specific activity of 117 U/mg. The purified enzyme was estimated to be composed of two subunits of ca. 72 and 45 kDa, as judged by SDS-polyacrylamide gel electrophoresis. The purified enzyme had maximum activity at pH 4.5 and showed the highest substrate specificity to ethanol, isoamyl alcohol, 1-butanol, and 1-propanol. The deduced sequences of cloned genes adhA and adhB encoding subunits I and II of PQQ-ADH showed 80 % amino acid (AA) identity to AdhA and 68 % AA identity to AdhB of Ga. europaeus V3 (LMG 18494). Because of the high similarity between genes encoding subunits I and II of PQQ-ADH and its homologous genes found in a distantly related taxonomic group of acetic acid bacteria, the results suggest the possibility of horizontal gene transfer between these two groups of genera.

  18. Conformation-sensitive capillary electrophoresis.

    PubMed

    Ashton, Emma Jane

    2011-01-01

    Conformation-sensitive capillary electrophoresis (CSCE) is a rapid, high-throughput screening method that can be applied to any region of a genome for detection of sequence variants. Slab gel-based conformation-sensitive gel electrophoresis was first described by Ganguly et al., and the transfer from slab gels to capillaries for higher throughput was reported by Rozycka et al. CSCE is based on the principle that DNA homoduplexes and heteroduplexes migrate at different rates during electrophoresis under mildly denaturing conditions. Fragments showing an altered peak morphology compared to the wild type are then sequenced to determine the precise nature of the sequence variant detected.

  19. Preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  20. Preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-03-24

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  1. Protein content and enzyme activities in methanol- and acetate-grown Methanosarcina thermophila.

    PubMed Central

    Jablonski, P E; DiMarco, A A; Bobik, T A; Cabell, M C; Ferry, J G

    1990-01-01

    The cell extract protein content of acetate- and methanol-grown Methanosarcina thermophila TM-1 was examined by two-dimensional polyacrylamide gel electrophoresis. More than 100 mutually exclusive spots were present in acetate- and methanol-grown cells. Spots corresponding to acetate kinase, phosphotransacetylase, and the five subunits of the carbon monoxide dehydrogenase complex were identified in acetate-grown cells. Activities of formylmethanofuran dehydrogenase, formylmethanofuran:tetrahydromethanopterin formyltransferase, 5,10-methenyltetrahydromethanopterin cyclohydrolase, methylene tetrahydromethanopterin:coenzyme F420 oxidoreductase, formate dehydrogenase, and carbonic anhydrase were examined in acetate- and methanol-grown Methanosarcina thermophila. Levels of formyltransferase in either acetate- or methanol-grown Methanosarcina thermophila were approximately half the levels detected in H2-CO2-grown Methanobacterium thermoautotrophicum. All other enzyme activities were significantly lower in acetate- and methanol-grown Methanosarcina thermophila. Images FIG. 1 FIG. 2 PMID:2307649

  2. DNA typing by capillary electrophoresis

    SciTech Connect

    Zhang, N.

    1997-10-08

    Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.

  3. Capillary Electrophoresis in Wine Science.

    PubMed

    Coelho, Christian; Bagala, Franck; Gougeon, Régis D; Schmitt-Kopplin, Philippe

    2016-01-01

    Capillary electrophoresis appeared to be a powerful and reliable technique to analyze the diversity of wine compounds. Wine presents a great variety of natural chemicals coming from the grape berry extraction and the fermentation processes. The first and more abundant after water, ethanol has been quantified in wines via capillary electrophoresis. Other families like organic acids, neutral and acid sugars, polyphenols, amines, thiols, vitamins, and soluble proteins are electrophoretically separated from the complex matrix.Here, we will focus on the different methodologies that have been employed to conduct properly capillary electrophoresis in wine analysis.Two examples informing on wine chemistry obtained by capillary electrophoresis will be detailed. They concern polyphenol analysis and protein profiling. The first category is a well-developed quantitative approach important for the quality and the antioxidant properties conferred to wine. The second aspect involves more research aspects dealing with microbiota infections in the vineyard or in the grape as well as enological practices. PMID:27645750

  4. Biomedical applications of capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  5. Electrophoresis for Under Five Dollars.

    ERIC Educational Resources Information Center

    Lumetta, Vincent J.; Doktycz, Mitchel J.

    1994-01-01

    Equipped with a little more than batteries, food-dye, and sieving media, teachers can demonstrate an essential process used in biochemical research. An activity is provided to aid in helping students to understand electrophoresis. (ZWH)

  6. Copolymers For Capillary Gel Electrophoresis

    DOEpatents

    Liu, Changsheng; Li, Qingbo

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  7. Antibody enhancement of free-flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Cohly, H. H. P.; Morrison, Dennis R.; Atassi, M. Zouhair

    1988-01-01

    Specific T cell clones and antibodies (ABs) were developed to study the efficiency of purifying closely associated T cells using Continuous Flow Electrophoresis System. Enhanced separation is accomplished by tagging cells first with ABs directed against the antigenic determinants on the cell surface and then with ABs against the Fc portion of the first AB. This second AB protrudes sufficiently beyond the cell membrane and glycocalyx to become the major overall cell surface potential determinant and thus causes a reduction of electrophoretic mobility. This project was divided into three phases. Phase one included development of specific T cell clones and separation of these specific clones. Phase two extends these principles to the separation of T cells from spleen cells and immunized lymph node cells. Phase three applies this double antibody technique to the separation of T cytotoxic cells from bone marrow.

  8. Electrophoresis as a management tool

    USGS Publications Warehouse

    Morgan, R.P.; Chapman, J.A.; Noe, L.A.; Henny, C.J.

    1974-01-01

    The theme of this 1974 Northeast Fish and Wildlife Conference is 'A New Era'. Indeed, it is a new era for improved techniques to assist in management of our fish and wildlife resources for the maximum benefit of all. In some cases, the new techniques are primarily used in research.on fish and wildlife, and the results from the research are used to aid management and enforcement agencies in the decision-making process. One of the newer techniques that is being applied to problems in fisheries and wildlife is electrophoresis. In this paper, we review briefly the techniques of electrophoresis and illustrate research problems in wildlife and fisheries where the use of electrophoresis is now assisting or may potentially aid in management decisions.

  9. PNEUMATIC MICROVALVE FOR ELECTROKINETIC SAMPLE PRECONCENTRATION AND CAPILLARY ELECTROPHORESIS INJECTION

    SciTech Connect

    Cong, Yongzheng; Rausch, Sarah J.; Geng, Tao; Jambovane, Sachin R.; Kelly, Ryan T.

    2014-10-27

    Here we show that a closed pneumatic microvalve on a PDMS chip can serve as a semipermeable membrane under an applied potential, enabling current to pass through while blocking the passage of charged analytes. Enrichment of both anionic and cationic species has been demonstrated, and concentration factors of ~70 have been achieved in just 8 s. Once analytes are concentrated, the valve is briefly opened and the sample is hydrodynamically injected onto an integrated microchip or capillary electrophoresis (CE) column. In contrast to existing preconcentration approaches, the membrane-based method described here enables both rapid analyte concentration as well as high resolution separations.

  10. Contactless conductivity detector for microchip capillary electrophoresis

    NASA Technical Reports Server (NTRS)

    Pumera, Martin; Wang, Joseph; Opekar, Frantisek; Jelinek, Ivan; Feldman, Jason; Lowe, Holger; Hardt, Steffen; Svehla, D. (Principal Investigator)

    2002-01-01

    A microfabricated electrophoresis chip with an integrated contactless conductivity detection system is described. The new contactless conductivity microchip detector is based on placing two planar sensing aluminum film electrodes on the outer side of a poly(methyl methacrylate) (PMMA) microchip (without contacting the solution) and measuring the impedance of the solution in the separation channel. The contactless route obviates problems (e.g., fouling, unwanted reactions) associated with the electrode-solution contact, offers isolation of the detection system from high separation fields, does not compromise the separation efficiency, and greatly simplifies the detector fabrication. Relevant experimental variables, such as the frequency and amplitude of the applied ac voltage or the separation voltage, were examined and optimized. The detector performance was illustrated by the separation of potassium, sodium, barium, and lithium cations and the chloride, sulfate, fluoride, acetate, and phosphate anions. The response was linear (over the 20 microM-7 mM range) and reproducible (RSD = 3.4-4.9%; n = 10), with detection limits of 2.8 and 6.4 microM (for potassium and chloride, respectively). The advantages associated with the contactless conductivity detection, along with the low cost of the integrated PMMA chip/detection system, should enhance the power and scope of microfluidic analytical devices.

  11. Methane from acetate.

    PubMed

    Ferry, J G

    1992-09-01

    The general features are known for the pathway by which most methane is produced in nature. All acetate-utilizing methanogenic microorganisms contain CODH which catalyzes the cleavage of acetyl-CoA; however, the pathway differs from all other acetate-utilizing anaerobes in that the methyl group is reduced to methane with electrons derived from oxidation of the carbonyl group of acetyl-CoA to CO2. The current understanding of the methanogenic fermentation of acetate provides impressions of nature's novel solutions to problems of methyl transfer, electron transport, and energy conservation. The pathway is now at a level of understanding that will permit productive investigations of these and other interesting questions in the near future. PMID:1512186

  12. Bioprocessing: Prospects for space electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    The basic principles of electrophoresis are reviewed in light of its past contributions to biology and medicine. The near-zero gravity environment of orbiting spacecraft may present some unique advantages for a variety of processes, by abolishing the major source of convection in fluids. As the ground-based development of electrophoresis was heavily influenced by the need to circumvent the effects of gravity, this process should be a prime candidate for space operation. Nevertheless, while a space facility for electrophoresis may overcome the limitations imposed by gravity, it will not necessarily overcome all problems inherent in electrophoresis. These are, mainly, electroosmosis and the dissipation of the heat generated by the electric field. The NASA program has already led to excellent coatings to prevent electroosmosis, while the need for heat dissipation will continue to impose limits on the actual size of equipment. It is also not excluded that, once the dominant force of gravity is eliminated, disturbances in fluid stability may originate from weaker forces, such as surface tension.

  13. Mixed matrix membrane development.

    PubMed

    Kulprathipanja, Santi

    2003-03-01

    Two types of mixed matrix membranes were developed by UOP in the late 1980s. The first type includes adsorbent polymers, such as silicalite-cellulose acetate (CA), NaX-CA, and AgX-CA mixed matrix membranes. The silicalite-CA has a CO(2)/H(2) selectivity of 5.15 +/- 2.2. In contrast, the CA membrane has a CO(2)/H(2) selectivity of 0.77 +/- 0.06. The second type of mixed matrix membrane is PEG-silicone rubber. The PEG-silicone rubber mixed matrix membrane has high selectivity for polar gases, such as SO(2), NH(3), and H(2)S.

  14. [Determination of serum proteins by high performance capillary zone electrophoresis].

    PubMed

    Zhang, N; Tang, Y; Hao, D M; Zheng, L; Qiu, G B

    1999-11-01

    The separation method of serum proteins was established with an untreared 50 microns i.d. x 47 cm (40 cm to detector) capillary and detection of absorbance at 200 nm. Analysis was performed by pressure injectction 17.23 kPa.s and by applying 23 kV in the constant voltage mode. Serum samples were diluted 40-folds with assay buffer (12.5 mmol/L sodium borate, 1 mmol/L calcium lactate, 0.7 mmol/L magnesium sulfate, 1 mmol/L EDTA were mixed). A normal control serum protein was separated into 6 fractions. In pregnant serum, the alpha 0 was an additionally unknown fraction. Comparison of capillary electrophoresis with conventional cellulose acetate electrophoresis for analysis of serum proteins from normal control, pregnant women multiple myeloma and tonic rachitis patients indicates that capillary clectrophoresis is a new technique for the analysis of serum proteins because of its high efficiency, on-line data processing and automation. Capillary electrophoresis is the reliable technique for clinical diagnosis of serum protein abnormalities.

  15. Acetobacter aceti possesses a proton motive force-dependent efflux system for acetic acid.

    PubMed

    Matsushita, Kazunobu; Inoue, Taketo; Adachi, Osao; Toyama, Hirohide

    2005-07-01

    Acetic acid bacteria are obligate aerobes able to oxidize ethanol, sugar alcohols, and sugars into their corresponding acids. Among them, Acetobacter and Gluconacetobacter species have very high ethanol oxidation capacity, leading to accumulation of vast amounts of acetic acid outside the cell. Since these bacteria are able to grow in media with high concentrations of acetic acid, they must possess a specific mechanism such as an efflux pump by which they can resist the toxic effects of acetic acid. In this study, the efflux pump of Acetobacter aceti IFO 3283 was examined using intact cells and membrane vesicles. The accumulation of acetic acid/acetate in intact cells was increased by the addition of a proton uncoupler and/or cyanide, suggesting the presence of an energy-dependent efflux system. To confirm this, right-side-out and inside-out membrane vesicles were prepared from A. aceti IFO 3283, and the accumulation of acetic acid/acetate in the vesicles was examined. Upon the addition of a respiratory substrate, the accumulation of acetic acid/acetate in the right-side-out vesicles was largely decreased, while its accumulation was very much increased in the inside-out vesicles. These respiration-dependent phenomena observed in both types of membrane vesicles were all sensitive to a proton uncoupler. Acetic acid/acetate uptake in the inside-out membrane vesicles was dependent not on ATP but on the proton motive force. Furthermore, uptake was shown to be rather specific for acetic acid and to be pH dependent, because higher uptake was observed at lower pH. Thus, A. aceti IFO 3283 possesses a proton motive force-dependent efflux pump for acetic acid.

  16. Determination of counter-ions in synthetic peptides by ion chromatography, capillary isotachophoresis and capillary electrophoresis.

    PubMed

    Mrozik, Wojciech; Markowska, Aleksandra; Guzik, Lukasz; Kraska, Bartłomiej; Kamysz, Wojciech

    2012-03-01

    The utility of three various analytical techniques [ion chromatography (IC), capillary electrophoresis (CE) and isotachophoresis (ITP)] was tested in the determination of counter-ions in synthetic peptides. The analyzed ions were acetates, trifluoroacetates and chlorides. IC provided the best results; CE, except limit of detection and limit of quantification, exhibited the comparable results. ITP was classified as the less useful because of the problem with the determination of the chloride ions. Nevertheless, all the three techniques were able to analyze trifluoroacetates and acetates ions with satisfactory results. Except analytical methods, three procedures using hydrochloric acid (HCl) (at two different concentrations) and acetic acid as sample solvents processed by lyophilization were tested. It has been found that the lyophilization not only by HCl but also by acetic acid is a simple and cheap procedure for removal of toxic trifluoroacetic counter-ions from peptides on satisfactory levels.

  17. Techniques For Focusing In Zone Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Twitty, Garland E.; Sammons, David W.

    1994-01-01

    In two techniques for focusing in zone electrophoresis, force of applied electrical field in each charged particle balanced by restoring force of electro-osmosis. Two techniques: velocity-gradient focusing (VGF), suitable for rectangular electrophoresis chambers; and field-gradient focusing (FGF), suitable for step-shaped electrophoresis chambers.

  18. Fragrance material review on phenethyl acetate.

    PubMed

    McGinty, D; Vitale, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of phenethyl acetate when used as a fragrance ingredient is presented. Phenethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for phenethyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, toxicokinetics, repeated dose, genotoxicity, and carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  19. Fragrance material review on benzyl acetate.

    PubMed

    McGinty, D; Vitale, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of benzyl acetate when used as a fragrance ingredient is presented. Benzyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for benzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, toxicokinetics, repeated dose, reproductive toxicity, genotoxicity, or carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Refer Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  20. Ratcheted electrophoresis of Brownian particles

    NASA Astrophysics Data System (ADS)

    Kowalik, Mikołaj; Bishop, Kyle J. M.

    2016-05-01

    The realization of nanoscale machines requires efficient methods by which to rectify unbiased perturbations to perform useful functions in the presence of significant thermal noise. The performance of such Brownian motors often depends sensitively on their operating conditions—in particular, on the relative rates of diffusive and deterministic motions. In this letter, we present a type of Brownian motor that uses contact charge electrophoresis of a colloidal particle within a ratcheted channel to achieve directed transport or perform useful work against an applied load. We analyze the stochastic dynamics of this model ratchet to show that it functions under any operating condition—even in the limit of strong thermal noise and in contrast to existing ratchets. The theoretical results presented here suggest that ratcheted electrophoresis could provide a basis for electrochemically powered, nanoscale machines capable of transport and actuation of nanoscale components.

  1. Capillary electrophoresis in food authenticity.

    PubMed

    Kvasnicka, Frantisek

    2005-06-01

    Food authenticity is a term which simply refers to whether the food purchased by the consumer matches its description. False description can occur in many forms, from the undeclared addition of water or other cheaper materials, or the wrong declaration of the amount of a particular ingredient in the product, to making false statements about the source of ingredients i.e., their geographic, plant, or animal origin. The aim of this review is to summarize applications of capillary electrophoresis in food authentication.

  2. Enhancing Centrifugal Separation With Electrophoresis

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1986-01-01

    Separation of biological cells by coil-planet centrifuge enhanced by electrophoresis. By itself, coil-planet centrifuge offers relatively gentle method of separating cells under low centrifugal force in physiological medium that keeps cells alive. With addition of voltage gradient to separation column of centrifuge, separation still gentle but faster and more complete. Since separation apparatus contains no rotary seal, probability of leakage, contamination, corrosion, and short circuits reduced.

  3. Capillary electrophoresis systems and methods

    SciTech Connect

    Dorairaj, Rathissh; Keynton, Robert S.; Roussel, Thomas J.; Crain, Mark M.; Jackson, Douglas J.; Walsh, Kevin M.; Naber, John F.; Baldwin, Richard P.; Franco, Danielle B.

    2011-08-02

    An embodiment of the invention is directed to a capillary electrophoresis apparatus comprising a plurality of separation micro-channels. A sample loading channel communicates with each of the plurality of separation channels. A driver circuit comprising a plurality of electrodes is configured to induce an electric field across each of the plurality of separation channels sufficient to cause analytes in the samples to migrate along each of the channels. The system further comprises a plurality of detectors configured to detect the analytes.

  4. Capillary Electrophoresis - Optical Detection Systems

    SciTech Connect

    Sepaniak, M. J.

    2001-08-06

    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  5. Acetate Production by Methanogenic Bacteria

    PubMed Central

    Westermann, Peter; Ahring, Birgitte K.; Mah, Robert A.

    1989-01-01

    Methanosarcina barkeri MS and 227 and Methanosarcina mazei S-6 produced acetate when grown on H2-CO2, methanol, or trimethylamine. Marked differences in acetate production by the two bacterial species were found, even though methane and cell yields were nearly the same. M. barkeri produced 30 to 75 μmol of acetate per mmol of CH4 formed, but M. mazei produced only 8 to 9 μmol of acetate per mmol of CH4. PMID:16348006

  6. Acetate dependence of tumors.

    PubMed

    Comerford, Sarah A; Huang, Zhiguang; Du, Xinlin; Wang, Yun; Cai, Ling; Witkiewicz, Agnes K; Walters, Holly; Tantawy, Mohammed N; Fu, Allie; Manning, H Charles; Horton, Jay D; Hammer, Robert E; McKnight, Steven L; Tu, Benjamin P

    2014-12-18

    Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation, and the regulation of gene expression. Highly glycolytic or hypoxic tumors must produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions. Here, we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors, and its activity is responsible for the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors.

  7. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  8. Fast separation and analysis of reduced monoclonal antibodies with capillary zone electrophoresis coupled to mass spectrometry.

    PubMed

    Zhao, Yimeng; Sun, Liangliang; Knierman, Michael D; Dovichi, Norman J

    2016-02-01

    Capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) was used for analysis of reduced antibodies. We first developed a simple protocol to condition commercial linear-polyacrylamide coated capillaries for use in top-down proteomics. We then suspended reduced antibodies in a solution of 35% acetic acid, 50% acetonitrile in water. Heavy and light chains were baseline resolved within 10 min and with 3-30 µg/mL detection limits using a 0.1% aqueous formic acid background electrolyte. Quintuplicate runs of a two-antibody mixture produced relative standard deviations of ∼1% in migration time and 10% in peak amplitudes. Resolution was further improved for the two-antibody mixture by using 5% acetic acid as the background electrolyte, highlighting the potential of capillary electrophoresis-mass spectrometry for analysis of antibody mixtures. PMID:26653481

  9. Gas separation membranes

    DOEpatents

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

  10. Capillary zone electrophoresis: an additional technique for the identification of hemoglobin variants.

    PubMed

    Lin, C; Cotton, F; Fontaine, B; Gulbis, B; Janssens, J; Vertongen, F

    1999-05-01

    Two capillary zone electrophoresis kits (Hb A2 and Hb A1c) were tested for confirmation and identification of hemoglobin variants. The capillary zone electrophoresis experiments were performed at pH 4.7 (Hb A1c kit) and 8.7 (Hb A2 kit) in a 24 cm uncoated fused silica capillary tube (25 microm I.D.). Normal hemoglobins and common hemoglobin variants, including Hbs S, D-Punjab, C, E, O-Arab, and G-Philadelphia, were successfully separated by both methods within a few minutes. Both systems provided completely different elution profiles of normal and abnormal hemoglobin fractions tested and were complementary. The inter-assay coefficient of variations of the migration times of hemoglobin variants were less than 1.0 and 1.3% by the Hb A2 and Hb A1c, respectively. This permits a higher resolution of some hemoglobin variants in low concentrations, like Hb S in newborns, compared with conventional electrophoresis methods. The present capillary zone electrophoresis methods are sensitive, rapid, not labor intensive, and highly selective for the separation of hemoglobin variants. Combination of both methods with some conventional methods, such as isoelectrofocusing, allows identification of Hbs C, E, O-Arab, S, and D-Punjab, as well as their quantification. We have demonstrated that the conventional electrophoresis methods (electrophoresis at pH 6.5 in citrate agar gel and electrophoresis at pH 8.6 on cellulose acetate) can be advantageously replaced by the present capillary zone electrophoresis methods in a clinical laboratory practice for the detection and quantification of hemoglobin variants. PMID:10335978

  11. Mathematical models of continuous flow electrophoresis: Electrophoresis technology

    NASA Technical Reports Server (NTRS)

    Saville, Dudley A.

    1986-01-01

    Two aspects of continuous flow electrophoresis were studied: (1) the structure of the flow field in continuous flow devices; and (2) the electrokinetic properties of suspended particles relevant to electrophoretic separations. Mathematical models were developed to describe flow structure and stability, with particular emphasis on effects due to buoyancy. To describe the fractionation of an arbitrary particulate sample by continuous flow electrophoresis, a general mathematical model was constructed. In this model, chamber dimensions, field strength, buffer composition, and other design variables can be altered at will to study their effects on resolution and throughput. All these mathematical models were implemented on a digital computer and the codes are available for general use. Experimental and theoretical work with particulate samples probed how particle mobility is related to buffer composition. It was found that ions on the surface of small particles are mobile, contrary to the widely accepted view. This influences particle mobility and suspension conductivity. A novel technique was used to measure the mobility of particles in concentrated suspensions.

  12. Enantiomer Separations by Capillary Electrophoresis.

    PubMed

    Scriba, Gerhard K E; Harnisch, Henrik; Zhu, Qingfu

    2016-01-01

    Capillary electrophoresis (CE) is a versatile and flexible technique for analytical enantioseparations. This is due to the large variety of chiral selectors as well as the different operation modes including electrokinetic chromatography, micellar electrokinetic chromatography, and microemulsion electrokinetic chromatography. The chiral selector, which is added to the background electrolyte, represents a pseudostationary phase with its own electrophoretic mobility allowing a variety of different separation protocols. The present chapter briefly addresses the basic fundamentals of CE enantioseparations as well as the most frequently applied chiral selectors and separation modes. The practical example illustrates the separation of the enantiomers of a positively charged analyte using native and charged cyclodextrin derivatives as chiral selectors. PMID:27645742

  13. Integrated multiplexed capillary electrophoresis system

    DOEpatents

    Yeung, Edward S.; Tan, Hongdong

    2002-05-14

    The present invention provides an integrated multiplexed capillary electrophoresis system for the analysis of sample analytes. The system integrates and automates multiple components, such as chromatographic columns and separation capillaries, and further provides a detector for the detection of analytes eluting from the separation capillaries. The system employs multiplexed freeze/thaw valves to manage fluid flow and sample movement. The system is computer controlled and is capable of processing samples through reaction, purification, denaturation, pre-concentration, injection, separation and detection in parallel fashion. Methods employing the system of the invention are also provided.

  14. Capillary electrophoresis in metallodrug development.

    PubMed

    Holtkamp, Hannah; Hartinger, Christian G

    2015-09-01

    Capillary electrophoresis (CE) is a separation method based on differential migration of analytes in electric fields. The compatibility with purely aqueous separation media makes it a versatile tool in metallodrug research. Many metallodrugs undergo ligand exchange reactions that can easily be followed with this method and the information gained can even be improved by coupling the CE to advanced detectors, such as mass spectrometers. This gives the method high potential to facilitate the development of metallodrugs, especially when combined with innovative method development and experimental design. PMID:26547417

  15. Continuous free-flow electrophoresis.

    PubMed

    Krivánková, L; Bocek, P

    1998-06-01

    This review evaluates the literature on continuous free flow electrophoresis, published during the last four years. Its aim is to serve not only experts in the field but also newcomers, and, therefore, it also briefly describes the principles of the method and the techniques used, referring to fundamental papers published earlier. The actual commercial instrumentation is briefly outlined. A substantial part of this review is devoted to the optimization of the performance of this method. Finally, diverse applications of fractionations of charged species in solution, ranging from small ions to biological particles and cells, are surveyed.

  16. Acetal phosphatidic acids: novel platelet aggregating agents.

    PubMed

    Brammer, J P; Maguire, M H; Walaszek, E J; Wiley, R A

    1983-05-01

    induce platelet aggregation per se by direct action at the platelet membrane, and that the acetal function is of primary importance in their potent platelet-stimulating activity. Moreover, as the acetal phosphatidic acids are the major components of the smooth muscle-contracting acidic phospholipid tissue extract ;Darmstoff' (Vogt, 1949), their potent platelet-aggregating properties may be of physiological or pathological significance.

  17. Ionic Liquids in Capillary Electrophoresis.

    PubMed

    Holzgrabe, Ulrike; Wahl, Joachim

    2016-01-01

    Recently, a great interest was drawn toward ionic liquids (ILs) in analytical separation techniques. ILs possess many properties making them excellent additives in capillary electrophoresis (CE) background electrolytes (BGE). The most important property is the charge of the dissolved ions in BGE enabling the cations to interact with deprotonated silanol groups on the capillary surface and thereby modifying the electroosmotic flow (EOF). Ionic and/or proton donor-acceptor interactions between analyte and IL are possible interactions facilitating new kinds of separation mechanisms in CE. Further advantages of ILs are the high conductivity, the environmentally friendliness, and the good solubility for organic and inorganic compounds. The most commonly used ILs in capillary electrophoresis are dialkylimidazolium-based ILs, whereas for enantioseparation a lot of innovative chiral cations and anions were investigated.ILs are reported to be additives to a normal CE background electrolyte or the sole electrolyte in CE, nonaqueous CE (NACE), micellar electrokinetic chromatography (MEKC), and in enantioseparation. An overview of applications and separation mechanisms reported in the literature is given here, in addition to the enantioseparation of pseudoephedrine using tetrabutylammonium chloride (TBAC) as IL additive to an ammonium formate buffer containing β-cyclodextrin (β-CD). PMID:27645735

  18. Capillary electrophoresis for drug analysis

    NASA Astrophysics Data System (ADS)

    Lurie, Ira S.

    1999-02-01

    Capillary electrophoresis (CE) is a high resolution separation technique which is amenable to a wide variety of solutes, including compounds which are thermally degradable, non-volatile and highly polar, and is therefore well suited for drug analysis. Techniques which have been used in our laboratory include electrokinetic chromatography (ECC), free zone electrophoresis (CZE) and capillary electrochromatography (CEC). ECC, which uses a charged run buffer additive which migrates counter to osmotic flow, is excellent for many applications, including, drug screening and analyses of heroin, cocaine and methamphetamine samples. ECC approaches include the use of micelles and charged cyclodextrins, which allow for the separation of complex mixtures. Simultaneous separation of acidic, neutral and basic solutes and the resolution of optical isomers and positional isomers are possible. CZE has been used for the analysis of small ions (cations and anions) in heroin exhibits. For the ECC and CZE experiments performed in our laboratory, uncoated capillaries were used. In contrast, CEC uses capillaries packed with high performance liquid chromatography stationary phases, and offers both high peak capacities and unique selectivities. Applications include the analysis of cannabinoids and drug screening. Although CE suffers from limited concentration sensitivity, it is still applicable to trace analysis of drug samples, especially when using injection techniques such as stacking, or detection schemes such as laser induced fluorescence and extended pathlength UV.

  19. Nonaqueous Capillary Electrophoresis Mass Spectrometry.

    PubMed

    Klampfl, Christian W; Himmelsbach, Markus

    2016-01-01

    The term nonaqueous capillary electrophoresis (NACE) commonly refers to capillary electrophoresis with purely nonaqueous background electrolytes (BGE). Main advantages of NACE are the possibility to analyze substances with very low solubility in aqueous media as well as separation selectivity that can be quite different in organic solvents (compared to water)-a property that can be employed for manipulation of separation selectivities. Mass spectrometry (MS) has become more and more popular as a detector in CE a fact that applies also for NACE. In the present chapter, the development of NACE-MS since 2004 is reviewed. Relevant parameters like composition of BGE and its influence on separation and detection in NACE as well as sheath liquid for NACE-MS are discussed. Finally, an overview of the papers published in the field of NACE-MS between 2004 and 2014 is given. Applications are grouped according to the field (analysis of natural products, biomedical analysis, food analysis, analysis of industrial products, and fundamental investigations). PMID:27645734

  20. Conducting Polymer Electrodes for Gel Electrophoresis

    PubMed Central

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D.

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation. PMID:24586761

  1. Membranes and Films from Polymers.

    ERIC Educational Resources Information Center

    Blumberg, Avrom A.

    1986-01-01

    Provides background information on polymeric films and membranes including production methods, special industrial and medical applications, laboratory preparation, and an experimental investigation of a porous cellulose acetate membrane. Presents a demonstration to distinguish between high- and low-density polyethylene. (JM)

  2. Membrane humidity control investigation

    NASA Technical Reports Server (NTRS)

    Elam, J.; Ruder, J.; Strumpf, H.

    1974-01-01

    The basic performance data on a hollow fiber membrane unit that removes water from a breathing gas loop by diffusion is presented. Using available permeability data for cellulose acetate, a preliminary design was made of a dehumidifier unit that would meet the problem statement.

  3. Liposome behavior in capillary electrophoresis.

    PubMed

    Roberts, M A; Locascio-Brown, L; Maccrehan, W A; Durst, R A

    1996-10-01

    The behavior of liposomes in capillary electrophoresis is studied for the purpose of developing a potential method for characterizing liposomes prepared for use in industrial and analytical applications. This study characterizes the electrophoretic behavior of liposomes under various conditions to provide information about electrophoretic mobility and liposome-capillary surface interactions. The results of this method are compared with the results obtained using traditional laser light-scattering methods to obtain size information about liposome preparations. Additionally, reactions of liposomes and the surfactant n-octyl-β-d-glucopyranoside are performed off-line in bulk solution experiments and on-line in the capillary. Automated delivery of lysis agents by multiple electrokinetic injections is demonstrated as a general method for inducing on-capillary reactions between liposomes and other reagents. Furthermore, some preliminary evidence on the use of liposomes as a hydrophobic partitioning medium for analytical separations is presented.

  4. Electrophoresis-mass spectrometry probe

    DOEpatents

    Andresen, Brian D.; Fought, Eric R.

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

  5. Electrophoresis-mass spectrometry probe

    DOEpatents

    Andresen, B.D.; Fought, E.R.

    1987-11-10

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface. 8 figs.

  6. Getting the Most out of Electrophoresis Units

    ERIC Educational Resources Information Center

    Mulvihill, Charlotte

    2007-01-01

    At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents…

  7. Compensating for Electro-Osmosis in Electrophoresis

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H.; Snyder, Robert S.

    1987-01-01

    Simple mechanical adjustment eliminates transverse velocity component. New apparatus for moving-wall electrophoresis increases degree of collimation of chemical species in sample stream. Electrophoresis chamber set at slight angle in horizontal plane to adjust angle between solution flow and wall motion. Component of velocity created cancels electro-osmotic effect.

  8. Analytical biotechnology: Capillary electrophoresis and chromatography

    SciTech Connect

    Horvath, C.; Nikelly, J.G.

    1990-01-01

    The papers describe the separation, characterization, and equipment required for the electrophoresis or chromatography of cyclic nucleotides, pharmaceuticals, therapeutic proteins, recombinant DNA products, pheromones, peptides, and other biological materials. One paper, On-column radioisotope detection for capillary electrophoresis, has been indexed separately for inclusion on the data base.

  9. Quantum magnetic deflagration in acetate.

    PubMed

    Hernández-Mínguez, A; Hernandez, J M; Macià, F; García-Santiago, A; Tejada, J; Santos, P V

    2005-11-18

    We report controlled ignition of magnetization reversal avalanches by surface acoustic waves in a single crystal of acetate. Our data show that the speed of the avalanche exhibits maxima on the magnetic field at the tunneling resonances of Mn(12). Combined with the evidence of magnetic deflagration in Mn(12) acetate, this suggests a novel physical phenomenon: deflagration assisted by quantum tunneling. PMID:16384178

  10. Quantum magnetic deflagration in acetate.

    PubMed

    Hernández-Mínguez, A; Hernandez, J M; Macià, F; García-Santiago, A; Tejada, J; Santos, P V

    2005-11-18

    We report controlled ignition of magnetization reversal avalanches by surface acoustic waves in a single crystal of acetate. Our data show that the speed of the avalanche exhibits maxima on the magnetic field at the tunneling resonances of Mn(12). Combined with the evidence of magnetic deflagration in Mn(12) acetate, this suggests a novel physical phenomenon: deflagration assisted by quantum tunneling.

  11. DNA Sequencing Using capillary Electrophoresis

    SciTech Connect

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  12. Two Electrophoresis Experiments for Freshmen in the Health Professions.

    ERIC Educational Resources Information Center

    Brabson, G. Dana; Waugh, David S.

    1986-01-01

    Describes procedures involved with paper electrophoresis separation of amino acids, gel electrophoresis separation of DNA, and design of an electrophoresis tank. Describes experiments using paper (amino acids) and gel (deoxyribonucleic acid fragments). Provides material lists, procedures, and discussion. (JM)

  13. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    SciTech Connect

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4

  14. Phenomenology of colloidal crystal electrophoresis

    NASA Astrophysics Data System (ADS)

    Medebach, Martin; Palberg, Thomas

    2003-08-01

    We studied the motion of polycrystalline solids comprising of charged sub-micron latex spheres suspended in deionized water. These were subjected to a low frequency alternating square wave electric field in an optical cell of rectangular cross section. Velocity profiles in X and Y direction were determined by Laser Doppler Velocimetry. The observed complex flow profiles are time dependent due to the combined effects of electro-osmosis, electrophoresis, crystal elasticity, and friction of the crystals at the cell wall. On small time scales elastic deformation occurs. On long time scales channel formation is observed. At intermediate times steady state profiles are dominated by a solid plug of polycrystalline material moving in the cell center. At large field strengths the plug shear melts. Mobilities in the shear molten state are on the order of (6.5±0.5) 10-8 m2 V-1 s-1 and connect continuously with those of the equilibrium fluid. The apparent mobility of the plug is much larger than of the fluid and like the mobility of the fluid decreases with increasing particle number density. We qualitatively attribute the accelerated motion of the plug to an incomplete exposure to the electro-osmotic flow profile.

  15. Nonlinear waves in capillary electrophoresis

    PubMed Central

    Ghosal, Sandip; Chen, Zhen

    2011-01-01

    Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care and forensics. In capillary electrophoresis the sample migrates in a microcapillary in the presence of a background electrolyte. When the ionic concentration of the sample is sufficiently high, the signal is known to exhibit features reminiscent of nonlinear waves including sharp concentration ‘shocks’. In this paper we consider a simplified model consisting of a single sample ion and a background electrolyte consisting of a single co-ion and a counterion in the absence of any processes that might change the ionization states of the constituents. If the ionic diffusivities are assumed to be the same for all constituents the concentration of sample ion is shown to obey a one dimensional advection diffusion equation with a concentration dependent advection velocity. If the analyte concentration is sufficiently low in a suitable non-dimensional sense, Burgers’ equation is recovered, and thus, the time dependent problem is exactly solvable with arbitrary initial conditions. In the case of small diffusivity either a leading edge or trailing edge shock is formed depending on the electrophoretic mobility of the sample ion relative to the background ions. Analytical formulas are presented for the shape, width and migration velocity of the sample peak and it is shown that axial dispersion at long times may be characterized by an effective diffusivity that is exactly calculated. These results are consistent with known observations from physical and numerical simulation experiments. PMID:20238181

  16. Electrophoresis of diffuse soft particles.

    PubMed

    Duval, Jérôme F L; Ohshima, Hiroyuki

    2006-04-11

    A theory is presented for the electrophoresis of diffuse soft particles in a steady dc electric field. The particles investigated consist of an uncharged impenetrable core and a charged diffuse polyelectrolytic shell, which is to some extent permeable to ions and solvent molecules. The diffuse character of the shell is defined by a gradual distribution of the density of polymer segments in the interspatial region separating the core from the bulk electrolyte solution. The hydrodynamic impact of the polymer chains on the electrophoretic motion of the particle is accounted for by a distribution of Stokes resistance centers. The numerical treatment of the electrostatics includes the possibility of partial dissociation of the hydrodynamically immobile ionogenic groups distributed throughout the shell as well as specific interaction between those sites with ions from the background electrolyte other than charge-determining ions. Electrophoretic mobilities are computed on the basis of an original numerical scheme allowing rigorous evaluation of the governing transport and electrostatic equations derived following the strategy reported by Ohshima, albeit within the restricted context of a discontinuous chain distribution. Attention is particularly paid to the influence of the type of distribution adopted on the electrophoretic mobility of the particle as a function of its size, charge, degree of permeability, and solution composition. The results are systematically compared with those obtained with a discontinuous representation of the interface. The theory constitutes a basis for interpreting electrophoretic mobilities of heterogeneous systems such as environmental or biological colloids or swollen/deswollen microgel particles.

  17. Atomic Force Controlled Capillary Electrophoresis

    NASA Astrophysics Data System (ADS)

    Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham

    2010-03-01

    Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.

  18. Comparison of non-electrophoresis grade with electrophoresis grade BIS in NIPAM polymer gel preparation

    PubMed Central

    Khodadadi, Roghayeh; Khajeali, Azim; Farajollahi, Ali Reza; Hajalioghli, Parisa; Raeisi, Noorallah

    2015-01-01

    Introduction:The main objective of this study was to investigate the possibility of replacing electrophoresis cross-linker with non-electrophoresis N, N′-methylenebisacrylamide (BIS) in N-isopropyl acrylamide (NIPAM) polymer gel and its possible effect on dose response. Methods: NIPAM polymer gel was prepared from non-electrophoresis grade BIS and the relaxation rate (R2) was measured by MR imaging after exposing the gel to gamma radiation from Co-60 source. To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of NIPAM gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. Results: It was found that the dose–response of NIPAM gel made from the non-electrophoresis grade BIS is coincident with that of electrophoresis grade BIS. Conclusion:Taken all, it can be concluded that the non-electrophoresis grade BIS not only is a suitable alternative for the electrophoresis grade BIS but also reduces the cost of gel due to its lower price. PMID:26457250

  19. High-performance capillary electrophoresis of histones

    SciTech Connect

    Gurley, L.R.; London, J.E.; Valdez, J.G.

    1991-01-01

    A high performance capillary electrophoresis (HPCE) system has been developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in a 0.1M phosphate buffer at pH 2.5 in a 50 {mu}m {times} 35 cm coated capillary. Electrophoresis was accomplished in 9 minutes separating a whole histone preparation into its components in the following order of decreasing mobility; (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B, (MHP) H2A (minor variant) where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase HPLC and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples. 27 refs., 8 figs.

  20. Capillary electrophoresis electrospray ionization mass spectrometry interface

    DOEpatents

    Smith, Richard D.; Severs, Joanne C.

    1999-01-01

    The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.

  1. Microfluidic flow counterbalanced capillary electrophoresis.

    PubMed

    Xia, Ling; Dutta, Debashis

    2013-04-01

    Flow counterbalanced capillary electrophoresis (FCCE) offers a powerful approach to realizing difficult charge based separations in compact microchip devices with application of relatively small electrical voltages. The need for dynamically controlling the pressure-gradient in the FCCE column however presents a significant challenge in implementing this technique on the microchip platform. In this article, we report the use of a simple on-chip pumping unit that allows precise introduction of a periodic pressure-driven backflow into a microfluidic separation channel enabling an FCCE analysis. The backflow in our device was produced by fabricating a shallow segment (0.5 μm deep) downstream of the analysis column (5 μm deep) and applying an electric field across it. A mismatch in the electroosmotic transport rate at the interface of this segment was shown to yield a pressure-gradient that could reverse the flow of the analyte bands without inverting the direction of the electric field. Although such a pressure-gradient also led to additional band broadening in the system, overall, the separation resolution of our device was observed to improve with an increasing number of back-and-forth sample passes through the analysis channel. For our current design, the corresponding improvement in the effective separation length was as much as 52% of the actual distance travelled by the chosen FITC-labeled amino acid samples. The reported device is well suited for further miniaturization of the FCCE method to the nanofluidic length scale which likely would improve its performance, and is easily integrable to other analytical procedures on the microchip platform for lab-on-a-chip applications. PMID:23420375

  2. Analysis of Small Ions with Capillary Electrophoresis.

    PubMed

    Aulakh, Jatinder Singh; Kaur, Ramandeep; Malik, Ashok Kumar

    2016-01-01

    Small inorganic ions are easily separated through capillary electrophoresis because they have a high charge-to-mass ratio and suffer little from some of the undesired phenomenon affecting higher molecular weight species like adsorption to the capillary wall, decomposition, and precipitation. This chapter is focused on the analysis of small ions other than metal ions using capillary electrophoresis. Methods are described for the determination of ions of nitrogen, phosphorus, sulfur, fluorine, chlorine, bromine, and iodine. PMID:27645739

  3. Affinity Electrophoresis Using Ligands Attached To Polymers

    NASA Technical Reports Server (NTRS)

    Van Alstine, James M.; Snyder, Robert S.; Harris, J. M.; Brooks, D. E.

    1990-01-01

    In new technique, reduction of electrophoretic mobilities by addition of polyethylene glycol to ligands increases electrophoretic separabilities. In immuno-affinity electrophoresis, modification of ligands extends specificity of electrophoretic separation to particles having surface electric-charge structures otherwise making them electrophoretically inseparable. Modification of antibodies by polyethylene glycol greatly reduces ability to aggregate while enhancing ability to affect electrophoretic mobilities of cells. In hydrophobic-affinity electrophoresis, addition of polyethylene glycol reduces tendency toward aggregation of cells or macromolecules.

  4. Free-Flow Open-Chamber Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Free-flow open-chamber electrophoresis variant of free-flow electrophoresis performed in chamber with open ends and in which velocity of electro-osmotic flow adjusted equal to and opposite mean electrophoretic velocity of sample. Particles having electrophoretic mobilities greater than mean mobility of sample particles move toward cathode, those with mobilities less move toward anode. Technique applied to separation of components of mixtures of biologically important substances. Sensitivity enhanced by use of tapered chamber.

  5. Acetate transport across the intestinal epithelium of an herbivorous teleost. [Oreochromis mossambicus

    SciTech Connect

    Titus, E.; Ahearn, G.A. )

    1990-02-26

    {sup 3}H-acetate transport across the upper intestine of the tilapia, Oreochromis mossabicus, using brush border and basolateral membrane vesicles, and intestinal sheets mounted in modified Ussing chambers was investigated. Brush border and basolateral vesicles demonstrated qualitatively similar anion antiport activity where, in the presence of a full profile of organic and inorganic anions, volatile fatty acids (VFA; acetate, propionate, butyrate) and bicarbonate showed reciprocal trans-stimulation and cis-inhibition of {sup 3}H-acetate influx, suggesting both membranes had the same VFA/bicarbonate exchange mechanism. Kinetic analysis of {sup 3}H-acetate influx into brush border and basolateral vesicles revealed different half-saturation constants (Km) as a function of external acetate concentrations (6.43 mM and 11.91 mM, respectively) and as a function of internal bicarbonate (5.89 mM and 0.41 mM, respectively). Intestinal sheets supported net absorptive fluxes when serosal acetate concentrations were held steady at 1.0 mM and mucosal acetate was varied from 1.60 to 10.0 mM. Unidirectional fluxes were significantly diminished by the addition of acetazolamide. This study postulates a transcellular transport pathway for VFA whereby qualitatively similar antiporters in series lead to a downhill flow of luminal acetate to the blood, which is driven by intracellular carbonic anhydrase and a transmural VFA concentration gradient.

  6. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    PubMed

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels.

  7. Acid diffusion through polyaniline membranes

    SciTech Connect

    Su, T.M.; Huang, S.C.; Conklin, J.A.

    1995-12-01

    Polyaniline membranes in the undoped (base) and doped (acid) forms are studied for their utility as pervaporation membranes. The separation of water from mixtures of propionic acid, acetic acid and formic acid have been demonstrated from various feed compositions. Doped polyaniline displays an enhanced selectivity of water over these organic acids as compared with undoped polyaniline. For as-cast polyaniline membranes a diffusion coefficient (D) on the order of 10{sup -9} cm{sup 2}/sec has been determined for the flux of protons through the membranes using hydrochloric acid.

  8. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances § 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No....

  9. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances § 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No....

  10. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  11. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  12. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  13. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  14. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  15. Proteins causing membrane fouling in membrane bioreactors.

    PubMed

    Miyoshi, Taro; Nagai, Yuhei; Aizawa, Tomoyasu; Kimura, Katsuki; Watanabe, Yoshimasa

    2015-01-01

    In this study, the details of proteins causing membrane fouling in membrane bioreactors (MBRs) treating real municipal wastewater were investigated. Two separate pilot-scale MBRs were continuously operated under significantly different operating conditions; one MBR was a submerged type whereas the other was a side-stream type. The submerged and side-stream MBRs were operated for 20 and 10 days, respectively. At the end of continuous operation, the foulants were extracted from the fouled membranes. The proteins contained in the extracted foulants were enriched by using the combination of crude concentration with an ultrafiltration membrane and trichloroacetic acid precipitation, and then separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The N-terminal amino acid sequencing analysis of the proteins which formed intensive spots on the 2D-PAGE gels allowed us to partially identify one protein (OmpA family protein originated from genus Brevundimonas or Riemerella anatipestifer) from the foulant obtained from the submerged MBR, and two proteins (OprD and OprF originated from genus Pseudomonas) from that obtained from the side-stream MBR. Despite the significant difference in operating conditions of the two MBRs, all proteins identified in this study belong to β-barrel protein. These findings strongly suggest the importance of β-barrel proteins in developing membrane fouling in MBRs.

  16. Proteins causing membrane fouling in membrane bioreactors.

    PubMed

    Miyoshi, Taro; Nagai, Yuhei; Aizawa, Tomoyasu; Kimura, Katsuki; Watanabe, Yoshimasa

    2015-01-01

    In this study, the details of proteins causing membrane fouling in membrane bioreactors (MBRs) treating real municipal wastewater were investigated. Two separate pilot-scale MBRs were continuously operated under significantly different operating conditions; one MBR was a submerged type whereas the other was a side-stream type. The submerged and side-stream MBRs were operated for 20 and 10 days, respectively. At the end of continuous operation, the foulants were extracted from the fouled membranes. The proteins contained in the extracted foulants were enriched by using the combination of crude concentration with an ultrafiltration membrane and trichloroacetic acid precipitation, and then separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The N-terminal amino acid sequencing analysis of the proteins which formed intensive spots on the 2D-PAGE gels allowed us to partially identify one protein (OmpA family protein originated from genus Brevundimonas or Riemerella anatipestifer) from the foulant obtained from the submerged MBR, and two proteins (OprD and OprF originated from genus Pseudomonas) from that obtained from the side-stream MBR. Despite the significant difference in operating conditions of the two MBRs, all proteins identified in this study belong to β-barrel protein. These findings strongly suggest the importance of β-barrel proteins in developing membrane fouling in MBRs. PMID:26360742

  17. Recent advances in affinity capillary electrophoresis for binding studies.

    PubMed

    Albishri, Hassan M; El Deeb, Sami; AlGarabli, Noura; AlAstal, Raghda; Alhazmi, Hassan A; Nachbar, Markus; El-Hady, Deia Abd; Wätzig, Hermann

    2014-01-01

    The present review covers recent advances and important applications of affinity capillary electrophoresis (ACE). It provides an overview about various ACE types, including ACE-MS, the multiple injection mode, the use of microchips and field-amplified sample injection-ACE. The most common scenarios of the studied affinity interactions are protein-drug, protein-metal ion, protein-protein, protein-DNA, protein-carbohydrate, carbohydrate-drug, peptide-peptide, DNA-drug and antigen-antibody. Approaches for the improvements of ACE in term of precision, rinsing protocols and sensitivity are discussed. The combined use of computer simulation programs to support data evaluation is presented. In conclusion, the performance of ACE is compared with other techniques such as equilibrium dialysis, parallel artificial membrane permeability assay, high-performance affinity chromatography as well as surface plasmon resonance, ultraviolet, circular dichroism, nuclear magnetic resonance, Fourier transform infrared, fluorescence, MS and isothermal titration calorimetry. PMID:25534793

  18. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food... GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by...

  19. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may...

  20. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food... Specific Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid....

  1. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food... Specific Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid....

  2. 21 CFR 184.1185 - Calcium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium acetate. 184.1185 Section 184.1185 Food... Specific Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid....

  3. Sealing leaks in geomembrane liners using electrophoresis

    SciTech Connect

    Darilek, G.T.; Corapcioglu, M.Y.; Yeung, A.T.

    1996-06-01

    An innovative method was demonstrated to seal leaks in geomembrane liners by attracting clay particles to the leaks using electrophoresis. Electrophoresis is the movement of electrically charged particles suspended in a liquid by the action of an electric field. A direct-current voltage impressed across the liner causes electrical current to flow through the leaks. The current produces a strong electric field at leaks. When a clay slurry is dispersed into the liquid in the impoundment, electrophoresis attracts the clay particles to the leaks, thereby sealing them. The method can seal leaks in liquid impoundments without removing the liquid or locating or accessing the leaks. The laboratory and full-scale test results were remarkable in that electrophoresis sealed the leaks completely when a layer of geofabric was under the liner, and electrophoresis reduced the leakage rate through holes as large as 10 mm in diameter by a factor of 1,600 in the field test with gravel under the liner, and by a factor of 1,667 in the laboratory basin with geonet under the liner.

  4. Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels

    NASA Astrophysics Data System (ADS)

    Pielesz, A.

    In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants.

  5. Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels.

    PubMed

    Pielesz, A

    2012-07-01

    In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants.

  6. Vibrational spectroscopy and electrophoresis as a "golden means" in monitoring of polysaccharides in medical plant and gels.

    PubMed

    Pielesz, A

    2012-07-01

    In recent years, some bioactive polysaccharides isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. Of them, polysaccharides or their glycoconjugates were shown to exhibit multiple biological activities including anticarcinogenic, anticoagulant, immunostimulating, antioxidant, etc. Pharmacotherapy using plant-derived substances can be currently regarded as a very promising future alternative to conventional therapy. The advanced biotechnologies available today enable chemical investigation of well-defined bioactive plant components as sources of novel drugs. The need for safer drugs without side effects has led to the use of natural ingredients with proven safety. Special interest is focused on plant polysaccharides. This article attempts to review the current structural and conformational characterization of some importantly bioactive monosaccharides isolated from following plant cell-wall: Symphytum officinale (comfrey), Thymus pulegioides (thyme), Trigonella foenum-graecum L. (fenugreek), Tussilago farfara L. (coltsfoot), Hyssopus officinalis (hyssop), Althaea officinalis L. (marshmallow) and Equisetum arvense L. (horsetail). The chemical structures of monosaccharides were analysed using FTIR and Raman spectroscopies as well as cellulose acetate membrane electrophoresis (CAE). The dried plant samples were gently hydrolysed with sulphuric acid. The presence of glucuronic acid, galacturonic acid, alginic acid, glucose, mannose and xylose in the hydrolysates of reference substances and non-defatted plant films was proved. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. Individual bands were selected to monitor the sugar content in medical plant cell walls and to confirm the identity of the analysed plants. PMID

  7. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. 721.10001 Section 721.10001 Protection of...-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate. (a) Chemical substances and significant...-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and...

  8. Free flow cell electrophoresis using zwitterionic buffer

    NASA Technical Reports Server (NTRS)

    Rodkey, R. Scott

    1990-01-01

    Studies of a zwitterionic buffer formulated for cell electrophoresis were done using the McDonnell-Douglas Continuous Flow Electrophoresis System. Standard buffers were analyzed for their stability in the electrical field and the results showed that both buffers tested were inherently unstable. Further, titration studies showed that the standards buffers buffered poorly at the pH employed for electrophoresis. The zwitterionic buffer buffered well at its nominal pH and was shown to be stable in the electrical field. Comparative studies of the buffer with standard cell separation buffers using formalin fixed rabbit and goose red blood cells showed that the zwitterionic buffer gave better resolution of the fixed cells. Studies with viable hybridoma cells showed that buffer Q supported cell viability equal to Hank's Balanced Salt Solution and that hybridoma cells in different stages of the growth cycle demonstrated reproducible differences in electrophoretic mobility.

  9. Detection of telomerase activity using microchip electrophoresis.

    PubMed

    Karasawa, Koji; Arakawa, Hidetoshi

    2015-07-01

    Telomerase participates in malignant transformation or immortalization of cells and thus has attracted attention as an anticancer drug target and diagnostic tumor marker. The telomeric repeat amplification protocol (TRAP) and improved TRAP methods (TRAP-fluorescence, TRAP-hybridization, etc.) are widely used forms of this telomerase assay. However, these approaches generally employ acrylamide gel electrophoresis after amplification of telomeric repeats by polymerase chain reaction (PCR), making these TRAP methods time consuming and technically demanding. In this study we developed a novel telomerase assay using microchip electrophoresis for rapid and highly sensitive detection of telomerase activity in cancer cells. The mixed gel of 0.8% hydroxypropyl methylcellulose (HPMC) and 0.3% polyethylene oxide (PEO) with SYBR Gold (fluorescent reagent) was used for microchip electrophoresis. As a result, the product amplified by a telomerase-positive cell could be measured in one cell per assay and detected with high reproducibility (CV=0.67%) in the short time of 100s.

  10. Purification by reflux electrophoresis of whey proteins and of a recombinant protein expressed in Dictyostelium discoideum.

    PubMed

    Corthals, G L; Collins, B M; Mabbutt, B C; Williams, K L; Gooley, A A

    1997-06-27

    Protein purification that combines the use of molecular mass exclusion membranes with electrophoresis is particularly powerful as it uses properties inherent to both techniques. The use of membranes allows efficient processing and is easily scaled up, while electrophoresis permits high resolution separation under mild conditions. The Gradiflow apparatus combines these two technologies as it uses polyacrylamide membranes to influence electrokinetic separations. The reflux electrophoresis process consists of a series of cycles incorporating a forward phase and a reverse phase. The forward phase involves collection of a target protein that passes through a separation membrane before trailing proteins in the same solution. The forward phase is repeated following clearance of the membrane in the reverse phase by reversing the current. We have devised a strategy to establish optimal reflux separation parameters, where membranes are chosen for a particular operating range and protein transfer is monitored at different pH values. In addition, forward and reverse phase times are determined during this process. Two examples of the reflux method are described. In the first case, we described the purification strategy for proteins from a complex mixture which contains proteins of higher electrophoretic mobility than the target protein. This is a two-step procedure, where first proteins of higher mobility than the target protein are removed from the solution by a series of reflux cycles, so that the target protein remains as the leading fraction. In the second step the target protein is collected, as it has become the leading fraction of the remaining proteins. In the second example we report the development of a reflux strategy which allowed a rapid one-step preparative purification of a recombinant protein, expressed in Dictyostelium discoideum. These strategies demonstrate that the Gradiflow is amenable to a wide range of applications, as the protein of interest is not

  11. Application of Microchip Electrophoresis for Clinical Tests

    NASA Astrophysics Data System (ADS)

    Yatsushiro, Shouki; Kataoka, Masatoshi

    Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. In addition, the analysis has expanded to an analytical field like not only the analysis of DNA but also the analysis of RNA, the protein, the sugar chain, and the cellular function, etc. In this report, we showed that high-performance monitoring systems for human blood glucose levels and α-amylase activity in human plasma using microchip electrophoresis.

  12. Undergraduate physics laboratory: Electrophoresis in chromatography paper

    NASA Astrophysics Data System (ADS)

    Hyde, Alexander; Batishchev, Oleg

    2015-12-01

    An experiment studying the physical principles of electrophoresis in liquids was developed for an undergraduate laboratory. We have improved upon the standard agarose gel electrophoresis experimental regime with a straightforward and cost-effective procedure, in which drops of widely available black food coloring were separated by electric field into their dye components on strips of chromatography paper soaked in a baking soda/water solution. Terminal velocities of seven student-safe dyes were measured as a function of the electric potential applied along the strips. The molecular mobility was introduced and calculated by analyzing data for a single dye. Sources of systematic and random errors were investigated.

  13. Preparation of Electrically Conductive Polymeric Membranes

    NASA Astrophysics Data System (ADS)

    Encinas, J. C.; Castillo-Ortega, M. M.; Rodríguez, F.; Castaño, V. M.

    2015-10-01

    Cellulose acetate porous membranes, coated with polyaniline, were chemically modified with polyelectrolytes to produce films of varying and controlled porosity and electrical conductivity. The highest electrical conductivity was obtained in membranes prepared with poly(styrene sulfonate) with large pore sizes. The electrical properties as well as scanning electron microscopy (SEM) images are discussed.

  14. Reductive opening of carbohydrate phenylsulfonylethylidene (PSE) acetals.

    PubMed

    Chéry, Florence; Cabianca, Elena; Tatibouët, Arnaud; De Lucchi, Ottorino; Lindhorst, Thisbe K; Rollin, Patrick

    2015-11-19

    The phenylsulfonylethylidene (PSE) acetal is a relatively new protecting group in carbohydrate chemistry. However, carbohydrate-derived phenylsulfonylethylidene (PSE) acetals show a different behavior in reductive desulfonylation than simple symmetrical acetals. Here we have investigated various SET-type reaction conditions in order to open PSE acetals regioselectively and to produce chiral ω-hydroxyethenyl ethers. Whereas sodium amalgam leads to a mixture of regioisomeric vinyl ethers besides the ethylidene acetal, samarium iodide is suited for regioselective ring opening. This is shown with seven different carbohydrate PSE acetals, both of the 1,3-dioxane and the 1,3-dioxolane type. PMID:26469209

  15. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  16. Role of gravity in preparative electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1975-01-01

    The fundamental formulas of electrophoresis are derived microscopically and applied to the problem of isotachophoresis. A simple physical model of the isotachophoresis front is proposed. The front motion and structure are studied in the simplified case without convection, diffusion and non-electric external forces.

  17. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory…

  18. Increasing Sensitivity In Continuous-Flow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Sensitivity of continuous-flow electrophoresis (CFE) chamber increased by introducing lateral gradients in concentration of buffer solution and thickness of chamber. Such gradients, with resulting enhanced separation, achieved in CFE chamber with wedge-shaped cross section and collateral flow. Enables improved separations of homogeneous components of mixtures of variety of biologically important substances.

  19. [Regulation of lipid metabolism in blood of weaving shop workers (noise level of about 90 dB A) by alpha-tocopherol acetate].

    PubMed

    Melkonian, M M

    1993-01-01

    alpha-Tocopherol acetate, used for repeated treatment within a year of weavers working under highly uncomfortable conditions (the level of noise up to 90 dB), was shown to exhibit the regulating effect on the rate of lipid peroxidation and on content of alpha-tocopherol and cholesterol in blood plasma and erythrocyte membranes as well as on the ratios alpha-tocopherol acetate/total lipids, alpha-tocopherol acetate/cholesterol in blood plasma and cholesterol/alpha-tocopherol acetate in erythrocyte membranes. The vitamin decreased distinctly the atherogenicity coefficient; these data suggest that treatment with tocopherol is essential for prophylaxis of noise-produced impairments.

  20. Fragrance material review on 2,4-dimethylbenzyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2,4-dimethylbenzyl acetate when used as a fragrance ingredient is presented. 2,4-Dimethylbenzyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, iso-butyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2,4-dimethylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  1. Fragrance material review on α-methylbenzyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of α-methylbenzyl acetate when used as a fragrance ingredient is presented. α-Methylbenzyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for α-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, and repeated dose data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  2. Fragrance material review on p-anisyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of p-anisyl acetate when used as a fragrance ingredient is presented. p-Anisyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for p-anisyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, and genotoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  3. Study on Dicarboxylic Acids in Aerosol Samples with Capillary Electrophoresis

    PubMed Central

    Adler, Heidi; Sirén, Heli

    2014-01-01

    The research was performed to study the simultaneous detection of a homologous series of α, ω-dicarboxylic acids (C2–C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50 μL. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2–C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10 ng/m3. PMID:24729915

  4. [Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].

    PubMed

    Zhao, Xinqing; Zhang, Mingming; Xu, Guihong; Xu, Jianren; Bai, Fengwu

    2014-03-01

    Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.

  5. [Conversion of acetic acid to methane by thermophiles]. Annual progress report

    SciTech Connect

    Zinder, S.H.

    1994-02-01

    Acetate is the precursor of approximately two-thirds of the methane produced by anaerobic bioreactors and many other methanogenic habitats. Besides their intrinsic interest, thermophilic acetotrophic methanogenic cultures usually grow at least twice as fast as their mesophilic counterparts, making them more amenable to study. In recent years, attention has been mainly focused on the thermophilic acetate utilizing methanogen Methanothrix strain CALS-1. Methanothrix, also called Methanosaeta, is one of only two methanogenic genera known to convert acetate to methane, the other being Methanosarcina. The faster-growing more versatile Methanosarcina has been better studied. However, when one examines anaerobic digestor contents, Methanothrix is often the dominant acetate-utilizing methanogen. As described in previous progress reports, the authors have achieved methanogenesis from acetate in cell-free extracts of Methanothrix strain CALS-1 grown in a pH auxostat. Using these cell extracts, specific activities for methanogenesis from acetate and ATP of 100--300 nmol/min were routinely obtained, levels comparable to the rate in whole cells, which is not usually the case in methanogenic extracts. Recently obtained results are given and discussed for the following: Methanogenesis in crude extracts; Role of the cell membrane in methanogenesis from acetate; Carbon monoxide dehydrogenase; Novel thermophilic cultures converting acetate to methane; and Methanol-utilizing methanogen.

  6. Carbon-isotopic analysis of dissolved acetate

    NASA Technical Reports Server (NTRS)

    Gelwicks, J. T.; Hayes, J. M.

    1990-01-01

    Heating of dried, acetate-containing solids together with oxalic acid dihydrate conveniently releases acetic acid for purification by gas chromatography. For determination of the carbon-isotopic composition of total acetate, the acetate-containing zone of the chromatographic effluent can be routed directly to a combustion furnace coupled to a vacuum system allowing recovery, purification, and packaging of CO2 for mass-spectrometric analysis. For analysis of methyl carbon, acetic acid can be cryogenically trapped from the chromatographic effluent, then transferred to a tube containing excess NaOH. The tube is evacuated, sealed, and heated to 500 degrees C to produce methane by pyrolysis of sodium acetate. Subsequent combustion of the methane allows determination of the 13C content at the methyl position in the parent acetate. With typical blanks, the standard deviation of single analyses is less than 0.4% for acetate samples larger than 5 micromoles. A full treatment of uncertainties is outlined.

  7. Ozone decomposition in aqueous acetate solutions

    SciTech Connect

    Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.

    1987-01-01

    The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.

  8. Using Gel Electrophoresis To Illustrate Protein Diversity and Isoelectric Point.

    ERIC Educational Resources Information Center

    Browning, Mark; Vanable, Joseph

    2002-01-01

    Demonstrates the differences in protein structures by focusing on isoelectric point with an experiment that is observable under certain pH levels in gel electrophoresis. Explains the electrophoresis procedure and reports results of the experiments. (YDS)

  9. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and....1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3 or C2H3O2Na·3H2O, CAS Reg. No. 6131-90-4) is the sodium salt of acetic acid and occurs naturally in plant and animal tissues....

  10. Effect of membrane polymeric materials on relationship between surface pore size and membrane fouling in membrane bioreactors

    NASA Astrophysics Data System (ADS)

    Miyoshi, Taro; Yuasa, Kotaku; Ishigami, Toru; Rajabzadeh, Saeid; Kamio, Eiji; Ohmukai, Yoshikage; Saeki, Daisuke; Ni, Jinren; Matsuyama, Hideto

    2015-03-01

    We investigated the effect of different membrane polymeric materials on the relationship between membrane pore size and development of membrane fouling in a membrane bioreactor (MBR). Membranes with different pore sizes were prepared using three different polymeric materials, cellulose acetate butyrate (CAB), polyvinyl butyral (PVB), and polyvinylidene fluoride (PVDF), and the development of membrane fouling in each membrane was evaluated by batch filtration tests using a mixed liquor suspension obtained from a laboratory-scale MBR. The results revealed that the optimal membrane pore size to mitigate membrane fouling differed depending on membrane polymeric material. For PVDF membranes, the degree of membrane fouling decreased as membrane pore size increased. In contrast, CAB membranes with smaller pores had less fouling propensity than those with larger ones. Such difference can be attributed to the difference in major membrane foulants in each membrane; in PVDF, they were small colloids or dissolved organics in which proteins are abundant, and in CAB, microbial flocs. The results obtained in this study strongly suggested that optimum operating conditions of MBRs differ depending on the characteristics of the used membrane.

  11. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  12. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  13. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  14. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  15. 21 CFR 582.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium acetate. 582.1721 Section 582.1721 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1721 Sodium acetate. (a) Product. Sodium acetate. (b) Conditions of use. This substance is...

  16. 21 CFR 556.380 - Melengestrol acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Melengestrol acetate. 556.380 Section 556.380 Food... Tolerances for Residues of New Animal Drugs § 556.380 Melengestrol acetate. A tolerance of 25 parts per billion is established for residues of the parent compound, melengestrol acetate, in fat of cattle....

  17. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  18. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  19. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  20. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  1. 21 CFR 582.6185 - Calcium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is...

  2. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  3. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  4. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  5. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  6. 21 CFR 582.1005 - Acetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  7. All natural cellulose acetate-Lemongrass essential oil antimicrobial nanocapsules.

    PubMed

    Liakos, Ioannis L; D'autilia, Francesca; Garzoni, Alice; Bonferoni, Cristina; Scarpellini, Alice; Brunetti, Virgilio; Carzino, Riccardo; Bianchini, Paolo; Pompa, Pier Paolo; Athanassiou, Athanassia

    2016-08-30

    Nanocapsules and nanoparticles play an essential role in the delivery of pharmaceutical agents in modern era, since they can be delivered in specific tissues and cells. Natural polymers, such as cellulose acetate, are becoming very important due to their availability, biocompatibility, absence of toxicity and biodegradability. In parallel, essential oils are having continuous growth in biomedical applications due to the inherent active compounds that they contain. A characteristic example is lemongrass oil that has exceptional antimicrobial properties. In this work, nanocapsules of cellulose acetate with lemongrass oil were developed with the solvent/anti-solvent method with resulting diameter tailored between 95 and 185nm. Various physico-chemical and surface analysis techniques were employed to investigate the formation of the nanocapsules. These all-natural nanocapsules found to well bioadhere to mucous membranes and to have very good antimicrobial properties at little concentrations against Escherichia coli and Staphylococcus aureus. PMID:26827919

  8. All natural cellulose acetate-Lemongrass essential oil antimicrobial nanocapsules.

    PubMed

    Liakos, Ioannis L; D'autilia, Francesca; Garzoni, Alice; Bonferoni, Cristina; Scarpellini, Alice; Brunetti, Virgilio; Carzino, Riccardo; Bianchini, Paolo; Pompa, Pier Paolo; Athanassiou, Athanassia

    2016-08-30

    Nanocapsules and nanoparticles play an essential role in the delivery of pharmaceutical agents in modern era, since they can be delivered in specific tissues and cells. Natural polymers, such as cellulose acetate, are becoming very important due to their availability, biocompatibility, absence of toxicity and biodegradability. In parallel, essential oils are having continuous growth in biomedical applications due to the inherent active compounds that they contain. A characteristic example is lemongrass oil that has exceptional antimicrobial properties. In this work, nanocapsules of cellulose acetate with lemongrass oil were developed with the solvent/anti-solvent method with resulting diameter tailored between 95 and 185nm. Various physico-chemical and surface analysis techniques were employed to investigate the formation of the nanocapsules. These all-natural nanocapsules found to well bioadhere to mucous membranes and to have very good antimicrobial properties at little concentrations against Escherichia coli and Staphylococcus aureus.

  9. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrophoresis apparatus for clinical use. 862... Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including...

  10. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrophoresis apparatus for clinical use. 862... Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An electrophoresis apparatus for clinical use is a device intended to separate molecules or particles, including...

  11. Perselectivity of porous cellulose nitrate membranes in evapomeation with temperature difference

    SciTech Connect

    Uragami, T.; Komatsu, R.; Miyata, T.

    1995-12-01

    Ethanol-permselectivity from aqueous ethanol solutions through porous cellulose nitrate membranes was investigated by evaporation with temperature difference under various conditions. On the other hand, same experiments using porous cellulose acetate were carried out. From these results of porous cellulose nitrate and cellulose acetate membranes, mechanism of permeation and separation for ethanol-permselectivity through cellulose nitrate membranes is discussed from viewpoints of physical and chemical structures of porous cellulose ester membranes.

  12. Photochemistry of 2-nitrobenzylidene acetals.

    PubMed

    Sebej, Peter; Solomek, Tomás; Hroudná, L'ubica; Brancová, Pavla; Klán, Petr

    2009-11-20

    Photolysis of dihydroxy compounds (diols) protected as 2-nitrobenzylidene acetals (ONBA) and subsequent acid- or base-catalyzed hydrolysis of the 2-nitrosobenzoic acid ester intermediates result in an efficient and high-yielding release of the substrates. We investigated the scope and limitations of ONBA photochemistry and expanded upon earlier described two-step procedures to show that the protected diols of many structural varieties can also be liberated in a one-pot procedure. In view of the fact that the acetals of nonsymmetrically substituted diols are converted into one of the corresponding 2-nitrosobenzoic acid ester isomers with moderate to high regioselectivity, the mechanism of their formation was studied using various experimental techniques. The experimental data were found to be in agreement with DFT-based quantum chemical calculations that showed the preferential cleavage occurs on the acetal C-O bond in the vicinity of more electron-withdrawing (or less electron-donating) groups. The study also revealed considerable complexity in the cleavage mechanism and that the structural variations in the substrate can significantly alter the reaction pathway. This deprotection strategy was found to be also applicable for 2-thioethanol when released from the corresponding monothioacetal in the presence of a reducing agent, such as ascorbic acid.

  13. Synthesis of cellulose acetate and carboxymethylcellulose from sugarcane straw.

    PubMed

    Candido, R G; Gonçalves, A R

    2016-11-01

    Sugarcane straw (SCS) is a raw material with high potential for production of cellulose derivatives due to its morphology and structure. The proposal of this work was to synthesize cellulose acetate (CA) and carboxymethylcellulose (CMC) from sugarcane straw cellulose, and applied the CA in the preparation of a membrane. The cellulose extraction was carried out in four steps. Firstly, SCS was treated with H2SO4 (10% v/v) followed by NaOH (5% w/v) treatment. Subsequently, a chelating process was performed before ending the extraction process with chemical bleaching using H2O2 (5% v/v). The extracted cellulose was employed in the obtainment of CA and CMC. The CA presented a degree of substitution (DS) of 2.72. Its FTIR spectrum showed that practically all hydroxyl groups were replaced by acetate groups. The membrane synthesized from CA was dense and homogeneous. The presence of small particles on the top and bottom surfaces decreased the mechanical resistance of the membrane. The CMC presented a low DS (0.4) demonstrating the carboxymethylation reaction was not very effective due to the presence of lignin. These results proved that SCS can be utilized in the synthesis of CA and CMC. PMID:27516319

  14. Synthesis of cellulose acetate and carboxymethylcellulose from sugarcane straw.

    PubMed

    Candido, R G; Gonçalves, A R

    2016-11-01

    Sugarcane straw (SCS) is a raw material with high potential for production of cellulose derivatives due to its morphology and structure. The proposal of this work was to synthesize cellulose acetate (CA) and carboxymethylcellulose (CMC) from sugarcane straw cellulose, and applied the CA in the preparation of a membrane. The cellulose extraction was carried out in four steps. Firstly, SCS was treated with H2SO4 (10% v/v) followed by NaOH (5% w/v) treatment. Subsequently, a chelating process was performed before ending the extraction process with chemical bleaching using H2O2 (5% v/v). The extracted cellulose was employed in the obtainment of CA and CMC. The CA presented a degree of substitution (DS) of 2.72. Its FTIR spectrum showed that practically all hydroxyl groups were replaced by acetate groups. The membrane synthesized from CA was dense and homogeneous. The presence of small particles on the top and bottom surfaces decreased the mechanical resistance of the membrane. The CMC presented a low DS (0.4) demonstrating the carboxymethylation reaction was not very effective due to the presence of lignin. These results proved that SCS can be utilized in the synthesis of CA and CMC.

  15. DNA electrophoresis in a nanofence array†

    PubMed Central

    Park, Sung-Gyu; Olson, Daniel W.

    2012-01-01

    We present the design and implementation of an oxidized silicon “nanofence array” for long DNA electrophoresis. The device consists of a periodic array of post-filled regions (the nanofences) alternating with empty channel regions. Even in this prototype version, the nanofence array provides the resolving power of a hexagonal nanopost array without requiring any direct-write nanopatterning steps such as electron-beam lithography. Through detailed single molecule investigations, we demonstrate that the origin of the resolving power of the nanofence array is not a reduction in band broadening, which might be expected from the theories for DNA electrophoresis in post arrays. Rather, the enhanced stretching of the hooked DNA by the uniform electric field between nanofences increases the efficiency of the collisions. PMID:22388662

  16. Theory of electrophoresis: fate of one equation.

    PubMed

    Gas, Bohuslav

    2009-06-01

    Electrophoresis utilizes a difference in movement of charged species in a separation channel or space for their spatial separation. A basic partial differential equation that results from the balance laws of continuous processes in separation sciences is the nonlinear conservation law or the continuity equation. Attempts at its analytical solution in electrophoresis go back to Kohlrausch's days. The present paper (i) reviews derivation of conservation functions from the conservation law as appeared chronologically, (ii) deals with theory of moving boundary equations and, mainly, (iii) presents the linear theory of eigenmobilities. It shows that a basic solution of the linearized continuity equations is a set of traveling waves. In particular cases the continuity equation can have a resonance solution that leads in practice to schizophrenic dispersion of peaks or a chaotic solution, which causes oscillation of electrolyte solutions.

  17. Iohexol in serum determined by capillary electrophoresis.

    PubMed

    Shihabi, Z K; Constantinescu, M S

    1992-10-01

    Iohexol, a nonionic compound used as a contrast medium for angiography and as a measure of the glomerular filtration rate, was quantified in serum by capillary electrophoresis. Comparable results were obtained for serum samples deproteinized with acetonitrile or analyzed directly after 50-fold dilution with borate buffer. Serum samples were electrophoresed for 2.6 min at 12 kV in a borate buffer with detection at 254 nm and with 3-isobutyl-1-methylxanthine as internal standard. Acetonitrile deproteinization gave a greater sensitivity than did sample dilution. Between-run CVs were between 4.7% and 6.7%, and within-run CVs were between 2.5 and 3.2%. Analytical recoveries were 95-105%. Results of the method compared well with those by high-performance liquid chromatography (slope 0.96, intercept 0.005 g/L). This method demonstrates the potential of capillary electrophoresis for rapid and simple quantification of small molecules.

  18. Electrokinetic Flow and Dispersion in Capillary Electrophoresis

    NASA Astrophysics Data System (ADS)

    Ghosal, Sandip

    2006-01-01

    Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care, and forensics. In capillary electrophoresis (which has evolved from its predecessor, slab-gel electrophoresis), the sample migrates through a single microcapillary instead of through the network of pores in a gel. A fundamental design problem is to minimize dispersion in the separation direction. Molecular diffusion is inevitable and sets a theoretical limit on the best separation that can be achieved. But in practice, there are a number of effects arising out of the interplay between fluid flow, chemistry, thermal effects, and electric fields that result in enhanced dispersion. This paper reviews the subject of fluid flow in such capillary microchannels and examines the various causes of enhanced dispersion that limit the efficiency of separation.

  19. Mathematical Models of Continuous Flow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Saville, D. A.; Snyder, R. S.

    1985-01-01

    Development of high resolution continuous flow electrophoresis devices ultimately requires comprehensive understanding of the ways various phenomena and processes facilitate or hinder separation. A comprehensive model of the actual three dimensional flow, temperature and electric fields was developed to provide guidance in the design of electrophoresis chambers for specific tasks and means of interpreting test data on a given chamber. Part of the process of model development includes experimental and theoretical studies of hydrodynamic stability. This is necessary to understand the origin of mixing flows observed with wide gap gravitational effects. To insure that the model accurately reflects the flow field and particle motion requires extensive experimental work. Another part of the investigation is concerned with the behavior of concentrated sample suspensions with regard to sample stream stability particle-particle interactions which might affect separation in an electric field, especially at high field strengths. Mathematical models will be developed and tested to establish the roles of the various interactions.

  20. A new approach to electrophoresis in space

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.; Rhodes, Percy H.

    1990-01-01

    Previous electrophoresis experiments performed in space are reviewed. There is sufficient data available from the results of these experiments to show that they were designed with incomplete knowledge of the fluid dynamics of the process including electrohydrodynamics. Redesigning laboratory chambers and operating procedures developed on Earth for space without understanding both the advantages and disadvantages of the microgravity environment has yielded poor separations of both cells and proteins. However, electrophoreris is still an important separation tool in the laboratory and thermal convection does limit its performance. Thus, there is a justification for electrophoresis but the emphasis of future space experiments must be directed toward basic research with model experiments to understand the microgravity environment and fluid analysis to test the basic principles of the process.

  1. Numerical simulation of electrophoresis separation processes

    NASA Technical Reports Server (NTRS)

    Ganjoo, D. K.; Tezduyar, T. E.

    1986-01-01

    A new Petrov-Galerkin finite element formulation has been proposed for transient convection-diffusion problems. Most Petrov-Galerkin formulations take into account the spatial discretization, and the weighting functions so developed give satisfactory solutions for steady state problems. Though these schemes can be used for transient problems, there is scope for improvement. The schemes proposed here, which consider temporal as well as spatial discretization, provide improved solutions. Electrophoresis, which involves the motion of charged entities under the influence of an applied electric field, is governed by equations similiar to those encountered in fluid flow problems, i.e., transient convection-diffusion equations. Test problems are solved in electrophoresis and fluid flow. The results obtained are satisfactory. It is also expected that these schemes, suitably adapted, will improve the numerical solutions of the compressible Euler and the Navier-Stokes equations.

  2. Metal Ions Analysis with Capillary Zone Electrophoresis.

    PubMed

    Malik, Ashok Kumar; Aulakh, Jatinder Singh; Kaur, Varinder

    2016-01-01

    Capillary electrophoresis has recently attracted considerable attention as a promising analytical technique for metal ion separations. Significant advances that open new application areas for capillary electrophoresis in the analysis of metal species occurred based on various auxiliary separation principles. These are mainly due to complexation, ion pairing, solvation, and micellization interactions between metal analytes and electrolyte additives, which alter the separation selectivity in a broad range. Likewise, many separation studies for metal ions have been concentrated on the use of preelectrophoresis derivatization methodology. Approaches suitable for manipulation of selectivity for different metal species including metal cations, metal complexes, metal oxoanions, and organometallic compounds, are discussed, with special attention paid to the related electrophoretic system variables using illustrative examples. PMID:27645740

  3. Capillary Electrophoresis in Food and Foodomics.

    PubMed

    Ibáñez, Clara; Acunha, Tanize; Valdés, Alberto; García-Cañas, Virginia; Cifuentes, Alejandro; Simó, Carolina

    2016-01-01

    Quality and safety assessment as well as the evaluation of other nutritional and functional properties of foods imply the use of robust, efficient, sensitive, and cost-effective analytical methodologies. Among analytical technologies used in the fields of food analysis and foodomics, capillary electrophoresis (CE) has generated great interest for the analyses of a large number of compounds due to its high separation efficiency, extremely small sample and reagent requirements, and rapid analysis. The introductory section of this chapter provides an overview of the recent applications of capillary electrophoresis (CE) in food analysis and foodomics. Relevant reviews and research articles on these topics are tabulated including papers published in the period 2011-2014. In addition, to illustrate the great capabilities of CE in foodomics the chapter describes the main experimental points to be taken into consideration for a metabolomic study of the antiproliferative effect of carnosic acid (a natural diterpene found in rosemary) against HT-29 human colon cancer cells. PMID:27645749

  4. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, E.S.; Taylor, J.A.

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figs.

  5. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S.; Taylor, John A.

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  6. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, E.S.; Taylor, J.A.

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figures.

  7. Multiplexed fluorescence detector system for capillary electrophoresis

    DOEpatents

    Yeung, Edward S.; Taylor, John A.

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  8. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D'Silva, Arthur

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conducts is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer.

  9. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D`Silva, A.

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.

  10. Method and apparatus for continuous electrophoresis

    DOEpatents

    Watson, Jack S.

    1992-01-01

    A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least one of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.

  11. A method and apparatus for continuous electrophoresis

    SciTech Connect

    Watson, J.S.

    1990-01-01

    A method and apparatus for conducting continuous separation of substances by electrophoresis are disclosed. The process involves electrophoretic separation combined with couette flow in a thin volume defined by opposing surfaces. By alternating the polarity of the applied potential and producing reciprocating short rotations of at least on of the surfaces relative to the other, small increments of separation accumulate to cause substantial, useful segregation of electrophoretically separable components in a continuous flow system.

  12. Commander prepares glass columns for electrophoresis experiment

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Commander Jack Lousma prepares on of the glass columns for the electrophoresis test in the middeck area of the Columbia. The experiment, deployed in an L-shaped mode in upper right corner, consists of the processing unit with glass columns in which the separation takes place; a camera (partially obscurred by Lousma's face) to document the process; and a cryogenic freezer to freeze and store the samples after separation.

  13. [The electrophoresis of biotinylated nucleic acids].

    PubMed

    Popa, L L; Pleşa, A; Repanovici, R; Popa, L M

    1992-01-01

    A simple and rapid method was worked out to evaluate the biotinylation level of the pBR322 and pSVK1H genetic cloning vectors, using gel electrophoresis. Avidin was used to slow down the migration of biotinylated DNA: the DNA migration speed diminished as the biotinylation level rose, due to DNA complexation. The highest level of biotinylation is characterized by the formation of a biotinylated nucleic acid-avidin complex with no electrophoretical mobility. PMID:1288639

  14. [2012 annual review of capillary electrophoresis technology].

    PubMed

    Qu, Feng; Zhao, Xinying; Wang, Yong

    2012-12-01

    This paper reviews the capillary electrophoresis (CE) in 2012. Four international and three national conferences are included and the important reports are introduced briefly. Literatures searched from ISI Web of Science ranged in 2012.1.1 - 2012.12.1 are classified and introduced based on the biology and medicine applications as well as the use of detectors and the important analytical chemical journals.

  15. Portable electrophoresis apparatus using minimum electrolyte

    NASA Technical Reports Server (NTRS)

    Stevens, M. R.; Vickers, J. M. (Inventor)

    1976-01-01

    An electrophoresis unit for use in conducting electrophoretic analysis of specimens is described. The unit includes a sealable container in which a substrate mounted specimen is suspended in an electrolytic vapor. A heating unit is employed to heat a supply of electrolyte to produce the vapor. The substrate is suspended within the container by being attached between a pair of clips which also serve as electrodes to which a direct current power source may be connected.

  16. Detection of telomerase activity using microchip electrophoresis.

    PubMed

    Karasawa, Koji; Arakawa, Hidetoshi

    2015-07-01

    Telomerase participates in malignant transformation or immortalization of cells and thus has attracted attention as an anticancer drug target and diagnostic tumor marker. The telomeric repeat amplification protocol (TRAP) and improved TRAP methods (TRAP-fluorescence, TRAP-hybridization, etc.) are widely used forms of this telomerase assay. However, these approaches generally employ acrylamide gel electrophoresis after amplification of telomeric repeats by polymerase chain reaction (PCR), making these TRAP methods time consuming and technically demanding. In this study we developed a novel telomerase assay using microchip electrophoresis for rapid and highly sensitive detection of telomerase activity in cancer cells. The mixed gel of 0.8% hydroxypropyl methylcellulose (HPMC) and 0.3% polyethylene oxide (PEO) with SYBR Gold (fluorescent reagent) was used for microchip electrophoresis. As a result, the product amplified by a telomerase-positive cell could be measured in one cell per assay and detected with high reproducibility (CV=0.67%) in the short time of 100s. PMID:25980765

  17. Electrophoresis: The Basics (by D. M. Hawcroft)

    NASA Astrophysics Data System (ADS)

    Voige, William H.

    1999-01-01

    D. M. Hawcroft. Oxford University Press: Oxford, 1997. 142 + xii pp. Index. ISBN 0-19-963563-3. $100.00. This concise monograph is one of a series on techniques in widespread use in biochemistry and cell and molecular biology. It seeks to present, in compact and readable form, the fundamentals of electrophoresis and does so very well. Both theory and practice are included, but emphasis is on the latter. Although the preface makes it clear that this book is intended for biologists, it also deserves a place in a truly complete chemistry library. The book is logically organized. Each of the nine chapters corresponds to either a step in an electrophoresis experiment (e.g., Chapter 7: Visualization of Separated Materials) or a major application (Chapter 4: The Electrophoresis of Native and Denatured Proteins). It is written as though the reader is getting ready to begin doing electrophoresis for the first time and needs a survey of the technique and its applications. A question that occurred to me repeatedly as I read through the book is: Exactly how did the author intend it to be used? One can view the book as either a text or a laboratory manual. As a resource that might be used as a supplementary text in a graduate or upper-division undergraduate course, it does an admirable job of presenting a thorough overview of modern electrophoresis. The figures and diagrams are exceptionally clear and present useful comparisons of results that can be obtained under a variety of conditions (e.g., the resolution of DNA fragments obtained with otherwise identical wedge and normal gels). Not all its explanations, however, are as cogent. It defines how the two portions of a discontinuous gel differ but fails to explain clearly how the porosity and pH differences result in the stacking effect, which is such a gel's primary advantage. Having it on hand as a laboratory manual would be much like having colleagues who are experts in all phases of electrophoresis to consult or to go to

  18. [Advances in the progress of anti-bacterial biofilms properties of acetic acid].

    PubMed

    Gao, Xinxin; Jin, Zhenghua; Chen, Xinxin; Yu, Jia'ao

    2016-06-01

    Bacterial biofilms are considered to be the hindrance in the treatment of chronic wound, because of their tolerance toward antibiotics and other antimicrobial agents. They also have strong ability to escape from the host immune attack. Acetic acid, as a kind of organic weak acid, can disturb the biofilms by freely diffusing through the bacterial biofilms and bacterial cell membrane structure. Then the acid dissociates to release the hydrogen ions, leading to the disorder of the acid-base imbalance, change of protein conformation, and the degradation of the DNA within the membranes. This paper reviews the literature on the characteristics and treatment strategies of the bacterial biofilms and the acetic acid intervention on them, so as to demonstrate the roles acetic acid may play in the treatment of chronic wound, and thus provide a convincing treatment strategy for this kind of disease. PMID:27321493

  19. [Advances in the progress of anti-bacterial biofilms properties of acetic acid].

    PubMed

    Gao, Xinxin; Jin, Zhenghua; Chen, Xinxin; Yu, Jia'ao

    2016-06-01

    Bacterial biofilms are considered to be the hindrance in the treatment of chronic wound, because of their tolerance toward antibiotics and other antimicrobial agents. They also have strong ability to escape from the host immune attack. Acetic acid, as a kind of organic weak acid, can disturb the biofilms by freely diffusing through the bacterial biofilms and bacterial cell membrane structure. Then the acid dissociates to release the hydrogen ions, leading to the disorder of the acid-base imbalance, change of protein conformation, and the degradation of the DNA within the membranes. This paper reviews the literature on the characteristics and treatment strategies of the bacterial biofilms and the acetic acid intervention on them, so as to demonstrate the roles acetic acid may play in the treatment of chronic wound, and thus provide a convincing treatment strategy for this kind of disease.

  20. Detection of biclonal gammopathy by capillary zone electrophoresis in a cat and a dog with plasma cell neoplasia.

    PubMed

    Facchini, Roberto Vailati; Bertazzolo, Walter; Zuliani, Davide; Bonfanti, Ugo; Caldin, Marco; Avallone, Giancarlo; Roccabianca, Paola

    2010-12-01

    Gammopathies associated with plasma cell neoplasms in a 15-year-old female spayed domestic shorthaired cat and a 9-year-old female spayed Rottweiler dog were evaluated by serum protein electrophoresis. In the cat, the plasma cell neoplasm was found in the liver and spleen, and an evaluable sample of bone marrow was not obtained. Some of the plasma cells had the morphologic appearance of flame cells. The paraprotein was confirmed as IgG based on agar gel immunodiffusion precipitation and both immunocytochemical and immunohistochemical staining. The dog had multiple myeloma with production of IgG and IgA paraproteins. In both cases, serum proteins were evaluated by 2 methods of protein electrophoresis: cellulose acetate electrophoresis (CAE) and capillary zone electrophoresis (CZE). In the cat and the dog, CAE showed a single large oligoclonal-like peak, which occurred in the γ-region in the cat and the β-γ-region in the dog, whereas CZE showed a biclonal gammopathy with 2 very close narrow spikes in the γ- and β-γ-regions in the cat and dog, respectively. In selected cases, CZE may be more effective than routine CAE in distinguishing oligoclonal from monoclonal or biclonal paraproteinemia.

  1. Phorbol myristate acetate receptors in human polymorphonuclear neutrophils

    SciTech Connect

    Nishihira, J.; O'Flaherty, J.T.

    1985-11-01

    Resting or phorbol myristate acetate (PMA)-pretreated neutrophils were disrupted by nitrogen cavitation and were fractionated on Percoll density gradients to identify the subcellular location of PMA receptors. Receptors were found in the cytoplasm of resting cells; neither primary nor secondary granules bound (/sup 3/H)PMA, and the few binding sites located in non-granule membrane fractions appeared to reflect cytosolic contamination. Contrastingly, PMA-pretreated cells lost cytosolic receptors; > 80% of PMA-binding sites were associated with non-granule membranes. Protein kinase C activity similarly shifted from cytosol to membranes after PMA treatment. Indeed, protein kinase C and PMA receptors co-sedimented on Percoll gradients, co-eluted from Ultragel AcA 44 columns loaded with neutrophil cytoplasm, and were identically influenced by various phospholipids. Finally, PMA, mezerein, diacylglycerol, and dialkylglycerol activated protein kinase C with potencies that paralleled their respective abilities to stimulate neutrophil aggregation responses and inhibit (/sup 3/H)PMA binding to whole cells or cytosol. These results fit a model of stimulus-response coupling wherein exogenous PMA or endogenous diacylglycerol solvate in cellular membranes. Cytosolic protein kinase C binds to the intramembranous ligand, forming an active, membrane-associated complex that phosphorylates nearby elements involved in triggering aggregation and other responses.

  2. Comparison of the polypeptide composition of Escherichia coli outer membranes prepared by two methods.

    PubMed Central

    Chopra, I; Shales, S W

    1980-01-01

    Escherichia coli outer membranes were prepared by centrifugation to equilibrium in sucrose gradients and then treated with Sarkosyl in the presence of ethylenediaminetetraacetate. The polypeptide profiles of the two outer membrane preparations were compared by two-dimensional polyacrylamide gel electrophoresis. The patterns obtained were not identical, and Sarkosyl removed several minor proteins from the outer membrane. Images PMID:6998960

  3. [The use of antioxidants (alpha-tocopherol acetate) in the treatment of diabetes mellitus].

    PubMed

    Kuznetsov, N S; Abulela, A M; Neskoromnyĭ, V N

    1993-01-01

    The authors have examined the time course of lipid peroxidation processes and the levels of total lipids in red cell membranes and blood plasma of diabetics administered alpha-tocopherol acetate. Patients with medium-severe diabetes of the first and second types were divided into 2 groups. Group 1 patients were administered only traditional sugar-reducing treatment, in Group 2 alpha-tocopherol acetate in a daily dose 300 mg was added to such therapy. Similar examinations were carried out in both the groups before and after the treatment. Lipid peroxidation levels and the content of total lipids were found significantly increased in the cellular membranes and blood plasma of Group 2 patients, whereas in Group 1 no changes of this kind were detected. Therapy with alpha-tocopherol acetate normalized lipid peroxidation processes in the red cell membranes and the total lipid content in the blood plasma, reduced the blood plasma level of lipid peroxidation products and the content of total lipids in red cell membranes. These results permit a conclusion on the favorable effect of alpha-tocopherol acetate on blood plasma lipid peroxidation and total lipid levels in diabetics.

  4. Development of nanofibrous cellulose acetate/gelatin skin substitutes for variety wound treatment applications.

    PubMed

    Vatankhah, Elham; Prabhakaran, Molamma P; Jin, Guorui; Mobarakeh, Laleh Ghasemi; Ramakrishna, Seeram

    2014-02-01

    The major component of fibrous extracellular matrix of dermis is composed of a complex combination of proteins and polysaccharides. Electrospun cellulose acetate/gelatin might be an effective simulator of the structure and composition of native skin and during this study, we electrospun cellulose acetate/gelatin membranes in various compositions and their performance as a scaffold for either skin tissue engineering or as a wound dressing was evaluated. Skin treatment products, whether tissue-engineered scaffolds or wound dressings, should be sufficiently hydrophilic to allow for gas and fluid exchange and absorb excess exudates while controlling the fluid loss. However, a wound dressing should be easily removable without causing tissue damage and a tissue-engineered scaffold should be able to adhere to the wound, and support cell proliferation during skin regeneration. We showed that these distinct adherency features are feasible just by changing the composition of cellulose acetate and gelatin in composite cellulose acetate/gelatin scaffolds. High proliferation of human dermal fibroblasts on electrospun cellulose acetate/gelatin 25:75 confirmed the capability of cellulose acetate/gelatin 25:75 nanofibers as a tissue-engineered scaffold, while the electrospun cellulose acetate/gelatin 75:25 can be a potential low-adherent wound dressing.

  5. Membrane stabilizer

    DOEpatents

    Mingenbach, William A.

    1988-01-01

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material.

  6. Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots

    DOEpatents

    Zhang, Jian-Shi; Giometti, Carol S.; Tollaksen, Sandra L.

    1989-01-01

    After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a DC power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. A high percentage extraction of proteins is achieved. The extracted proteins can be removed and subjected to partial digestion by trypsin or the like, followed by two-dimensional electrophoresis, resulting in a gel slab having a pattern of peptide gel spots which can be cored out and subjected to electrophoretic extraction to extract individual peptides.

  7. Acetic acid induces pH-independent cellular energy depletion in Salmonella enterica.

    PubMed

    Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A

    2015-03-01

    Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (p<0.05) that was apparent for the four Salmonella strains. We suggest that this effect was probably due solely to the action of undissociated acid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56 ± 1.27; p<0.05), where the role of both pH and undissociated acid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH.

  8. [Applications of microchip electrophoresis and capillary electrophoresis for screening FLT3-ITD gene mutation in acute myeloid leukemia].

    PubMed

    Leng, Xin; Li, Ling-Di; Li, Jin-Lan; Huang, Xiao-Jun; Ruan, Guo-Rui

    2014-02-01

    The purpose of the present study was to compare the reliability of microchip electrophoresis and capillary electrophoresis for screening FLT3-ITD gene mutation in acute myeloid leukemia. The FLT3-ITD mutation in the genomic DNA samples from 214 untreated AML patients were separately detected by PCR-microchip electrophoresis and PCR-capillary electrophoresis, then the DNA direct sequencing analysis was carried out. The results from PCR-microchip electrophoresis showed that there were 151 FLT3-ITD mutation negative, 58 FLT3-ITD mutation positive (58/214, 27.1%) and 5 FLT3-ITD mutation doubtful positive (5/214, 2.3%), while the outcomes from PCR-capillary electrophoresis displayed that there were 147 FLT3-ITD mutation negative and 67 FLT3-ITD mutation positive (67/214, 31.3%) without doubtful positive. In the 67 FLT3-ITD mutation positive samples detected by using PCR-capillary electrophoresis, 4 samples were detected as the negative while 5 samples were measured as the doubtful positive by using PCR-microchip electrophoresis. The followed sequencing analysis demonstrated that the above 9 samples were all FLT3-ITD mutation positive, indicating that PCR-capillary electrophoresis was more accurate and sensitive in screening the FLT3-ITD mutation, although statistic analysis showed that there were no significant differences in the detected results between PCR-microchip electrophoresis and PCR-capillary electrophoresis groups (Pearson Chi-squared Test, P > 0.05). It is concluded that both PCR-microchip electrophoresis and PCR-capillary electrophoresis were convenient and fast for screening FLT3-ITD mutation, but the accuracy of PCR-microchip electrophoresis awaits further improvement.

  9. Medroxyprogesterone acetate exacerbates glutamate excitotoxicity.

    PubMed

    Nilsen, Jon; Morales, Alison; Brinton, Roberta Diaz

    2006-07-01

    We previously demonstrated that progesterone functions as a neuroprotective agent whereas medroxyprogesterone acetate (MPA; Provera) does not. Moreover, MPA antagonized the neuroprotective and neurotrophic outcomes induced by 17beta-estradiol (E2). Towards developing effective hormone therapies for protection against neurodegeneration, we sought to determine whether formulation, chemical features or prevention versus treatment mode of exposure affected the outcome of MPA treatment in survival of primary hippocampal neurons. Results of these analyses indicated that both crystalline MPA and a pharmaceutical formulation (Depo-Provera) lacked neuroprotective efficacy, indicating that the effects were not dependent upon MPA formulation. Likewise, MPA in the prevention and treatment paradigms were equally ineffective at promoting neuronal survival, indicating that timing of MPA administration was not a factor. Further, the detrimental effects of MPA were not due to the presence of the acetate group, as medroxyprogesterone was as ineffective as MPA in promoting neuronal survival. Moreover, MPA pretreatment exacerbated neuron death induced by glutamate excitotoxicity as indicated by a 40% increase in neuron death determined by direct live/dead cell count and a commensurate increase in the number of positive cells by terminal deoxynucleotidyl transferase-mediated nick end-labeling. Collectively these results predict that the progestin formulation of hormone therapy will affect the vulnerability of the central nervous system to degenerative insults.

  10. Transcriptome analysis of acetic-acid-treated yeast cells identifies a large set of genes whose overexpression or deletion enhances acetic acid tolerance.

    PubMed

    Lee, Yeji; Nasution, Olviyani; Choi, Eunyong; Choi, In-Geol; Kim, Wankee; Choi, Wonja

    2015-08-01

    Acetic acid inhibits the metabolic activities of Saccharomyces cerevisiae. Therefore, a better understanding of how S. cerevisiae cells acquire the tolerance to acetic acid is of importance to develop robust yeast strains to be used in industry. To do this, we examined the transcriptional changes that occur at 12 h post-exposure to acetic acid, revealing that 56 and 58 genes were upregulated and downregulated, respectively. Functional categorization of them revealed that 22 protein synthesis genes and 14 stress response genes constituted the largest portion of the upregulated and downregulated genes, respectively. To evaluate the association of the regulated genes with acetic acid tolerance, 3 upregulated genes (DBP2, ASC1, and GND1) were selected among 34 non-protein synthesis genes, and 54 viable mutants individually deleted for the downregulated genes were retrieved from the non-essential haploid deletion library. Strains overexpressing ASC1 and GND1 displayed enhanced tolerance to acetic acid, whereas a strain overexpressing DBP2 was sensitive. Fifty of 54 deletion mutants displayed enhanced acetic acid tolerance. Three chosen deletion mutants (hsps82Δ, ato2Δ, and ssa3Δ) were also tolerant to benzoic acid but not propionic and sorbic acids. Moreover, all those five (two overexpressing and three deleted) strains were more efficient in proton efflux and lower in membrane permeability and internal hydrogen peroxide content than controls. Individually or in combination, those physiological changes are likely to contribute at least in part to enhanced acetic acid tolerance. Overall, information of our transcriptional profile was very useful to identify molecular factors associated with acetic acid tolerance.

  11. The fluid mechanics of continuous flow electrophoresis

    NASA Astrophysics Data System (ADS)

    Saville, D. A.

    1990-11-01

    The overall objective is to establish theoretically and confirm experimentally the ultimate capabilities of continuous flow electrophoresis chambers operating in an environment essentially free of particle sedimentation and buoyancy. The efforts are devoted to: (1) studying the effects of particle concentration on sample conductivity and dielectric constant. The dielectric constant and conductivity were identified as playing crucial roles in the behavior of the sample and on the resolving power and throughput of continuous flow devices; and (2) improving the extant mathematical models to predict flow fields and particle trajectories in continuous flow electrophoresis. A dielectric spectrometer was designed and built to measure the complex dielectric constant of a colloidal dispersion as a function of frequency between 500 Hz and 200 kHz. The real part of the signal can be related to the sample's conductivity and the imaginary part to its dielectric constant. Measurements of the dielectric constants of several different dispersions disclosed that the dielectric constants of dilute systems of the sort encountered in particle electrophoresis are much larger than would be expected based on the extant theory. Experiments were carried out to show that, in many cases, this behavior is due to the presence of a filamentary structure of small hairs on the particle surface. A technique for producing electrokinetically ideal synthetic latex particles by heat treating was developed. Given the ubiquitous nature of hairy surfaces with both cells and synthetic particles, it was deemed necessary to develop a theory to explain their behavior. A theory for electrophoretic mobility of hairy particles was developed. Finally, the extant computer programs for predicting the structure of electro-osmotically driven flows were extended to encompass flow channels with variable wall mobilities.

  12. The fluid mechanics of continuous flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Saville, D. A.

    1990-01-01

    The overall objective is to establish theoretically and confirm experimentally the ultimate capabilities of continuous flow electrophoresis chambers operating in an environment essentially free of particle sedimentation and buoyancy. The efforts are devoted to: (1) studying the effects of particle concentration on sample conductivity and dielectric constant. The dielectric constant and conductivity were identified as playing crucial roles in the behavior of the sample and on the resolving power and throughput of continuous flow devices; and (2) improving the extant mathematical models to predict flow fields and particle trajectories in continuous flow electrophoresis. A dielectric spectrometer was designed and built to measure the complex dielectric constant of a colloidal dispersion as a function of frequency between 500 Hz and 200 kHz. The real part of the signal can be related to the sample's conductivity and the imaginary part to its dielectric constant. Measurements of the dielectric constants of several different dispersions disclosed that the dielectric constants of dilute systems of the sort encountered in particle electrophoresis are much larger than would be expected based on the extant theory. Experiments were carried out to show that, in many cases, this behavior is due to the presence of a filamentary structure of small hairs on the particle surface. A technique for producing electrokinetically ideal synthetic latex particles by heat treating was developed. Given the ubiquitous nature of hairy surfaces with both cells and synthetic particles, it was deemed necessary to develop a theory to explain their behavior. A theory for electrophoretic mobility of hairy particles was developed. Finally, the extant computer programs for predicting the structure of electro-osmotically driven flows were extended to encompass flow channels with variable wall mobilities.

  13. Capillary zone electrophoresis in pharmaceutical analysis.

    PubMed

    Fanali, S; Cristalli, M; Nardi, A; Ossicini, L; Shukla, S K

    1990-06-01

    The paper presents a brief characterization of capillary zone electrophoresis, a modern analytical separation method with high expediency for practical applications, especially in pharmaceutical analysis. Basic theoretical considerations are presented and discussed to explain the effects of the operational parameters upon the separation efficiency and resolution of species. Descriptions of simple instrumentation and of the analytical procedure itself are given. Experimental examples are given of the separation of mixtures of pharmaceutically important compounds and of the effects of operational parameters, especially pH of BGE and voltage applied. Lastly, the practical application of CZE for analysis of isoxsuprine in commercial preparations is shown.

  14. Hybrid slab-microchannel gel electrophoresis system

    DOEpatents

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  15. Simul 5 - free dynamic simulator of electrophoresis.

    PubMed

    Hruska, Vlastimil; Jaros, Michal; Gas, Bohuslav

    2006-03-01

    We introduce the mathematical model of electromigration of electrolytes in free solution together with free software Simul, version 5, designed for simulation of electrophoresis. The mathematical model is based on principles of mass conservation, acid-base equilibria, and electroneutrality. It accounts for any number of multivalent electrolytes or ampholytes and yields a complete picture about dynamics of electromigration and diffusion in the separation channel. Additionally, the model accounts for the influence of ionic strength on ionic mobilities and electrolyte activities. The typical use of Simul is: inspection of system peaks (zones), stacking and preconcentrating analytes, resonance phenomena, and optimization of separation conditions, in either CZE, ITP, or IEF.

  16. Pulsed field gel electrophoresis for dairy propionibacteria.

    PubMed

    Chuat, Victoria; de Freitas, Rosangela; Dalmasso, Marion

    2015-01-01

    Pulsed field gel electrophoresis (PFGE) is a technique using alternating electric fields to migrate high molecular weight DNA fragments with a high resolution. This method consists of the digestion of bacterial chromosomal DNA with rare-cutting restriction enzymes and in applying an alternating electrical current between spatially distinct pairs of electrodes. DNA molecules migrate at different speeds according to the size of the fragments. Among other things, this technique is considered as the "gold standard" for genotyping, genetic fingerprinting, epidemiological studies, genome size estimation, and studying radiation-induced DNA damage and repair. This chapter describes a PFGE method that can be used to differentiate dairy propionibacteria. PMID:25862063

  17. Integrated chip-based capillary electrophoresis.

    PubMed

    Effenhauser, C S; Bruin, G J; Paulus, A

    1997-11-01

    Integrated capillary electrophoresis (ICE) is emerging as a new analytical tool allowing fast, automated, miniaturized and multiplexed assays, thus meeting the needs of the pharmaceutical industry in drug development. The current state-of-the-art of ICE is described with an emphasis on the choice of the support material (glass or polymeric materials), electrokinetic fluid handling, and injection and detection issues. Strategies and chip designs for pre- or post-column derivatization, DNA sequencing, on-line PCR analysis, on-chip enzymatic sample digestion, fraction isolation, and immunoassays are presented. The review concludes with a brief outlook.

  18. Electrohydrodynamic effects in continuous flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Rhodes, P. H.; Snyder, R. S.; Roberts, G. O.; Baygents, J. C.

    1991-01-01

    We demonstrate experimentally and theoretically the importance of electrohydrodynamic (EHD) flows in continuous-flow electrophoresis (CFE) separations. These flows are associated with variations in the conductivity or dielectric constant, and are quadratic in the field strength. They appear to be the main cause of extraneous and undesired flows in CFE which have degraded separation performance and have until now not been explained. We discuss the importance of EHD flows relative to other effects. We also describe possible techniques for reducing the associated degradation of CFE separations.

  19. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.

    2000-01-01

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  20. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.

    2004-06-15

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  1. Understanding Palladium Acetate from a User Perspective.

    PubMed

    Carole, William A; Colacot, Thomas J

    2016-06-01

    The behavior of palladium acetate is reviewed with respect to its synthesis, characterization, structure (in both solution and solid state), and activation pathways. In addition, comparisons of catalytic activities between pure palladium acetate and two common byproducts, Pd3 (OAc)5 (NO2 ) and polymeric [Pd(OAc)2 ]n , typically present in commercially available material are reviewed. Hence, this minireview serves as a concise guide for the users of palladium acetate from both academia and industry. PMID:27125630

  2. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  3. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  4. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  5. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  6. Field-amplified sample stacking and nonaqueous capillary electrophoresis determination of complex mixtures of polar aromatic sulfonates.

    PubMed

    Morales, Sergio; Cela, Rafael

    2002-02-01

    Nonaqueous CE and field-amplified sample stacking have been used in the determination of complex mixtures of polar aromatic sulfonates (AS; mainly benzene- and naphthalenesulfonates) of environmental concern. The analytical procedure consists of an on-column aqueous sample enrichment, followed by the nonaqueous electrophoretic determination of stacked aromatic sulfonates. Various organic solvents were used as separation medium, acetonitrile and N-methylformamide gave the best results. Optimum capillary electrophoresis separation is obtained with ammonium acetate (25 mM) dissolved in N-methylformamide-methanol (90:10) as background electrolyte. This combined method was applied to the analysis of surface water samples spiked with selected aromatic sulfonates derivatives.

  7. Scanning electrochemical microscopy as a readout tool for protein electrophoresis.

    PubMed

    Zhang, Meiqin; Wittstock, Gunther; Shao, Yuanhua; Girault, Hubert H

    2007-07-01

    Scanning electrochemical microscopy (SECM) was used to image silver-stained proteins on a poly(vinylidene difluoride) membrane. The method is based on measuring the current at a scanning microelectrode in the feedback mode. The electrochemical feedback is caused by the redox-mediated etching of the isolated 5 - 10-nm-diameter silver nanoparticles formed during the staining process. Several parameters, such as the redox mediator and the staining protocol, were optimized to ensure a high resolution and a low detection limit, i.e., 0.5 ng of bovine serum albumin (4 x 10(-14) mol) distributed on an area of 1 mm(2) (4 x 10(-16) mol x cm(-2)). Images of beta-lactoglobulin A and myoglobin bands after gel electrophoretic separation and electroblotting were obtained in order to demonstrate that SECM can be employed as a sensitive and quantitative readout method for detection of proteins after gel electrophoresis. An additional advantage is that the silver staining can be removed, allowing further downstream mass spectrometry analysis. PMID:17539601

  8. Enhancement of acetyl xylan esterase activity on cellulose acetate through fusion to a family 3 cellulose binding module.

    PubMed

    Mai-Gisondi, Galina; Turunen, Ossi; Pastinen, Ossi; Pahimanolis, Nikolaos; Master, Emma R

    2015-11-01

    The current study investigates the potential to increase the activity of a family 1 carbohydrate esterase on cellulose acetate through fusion to a family 3 carbohydrate binding module (CBM). Specifically, CtCBM3 from Clostridium thermocellum was fused to the carboxyl terminus of the acetyl xylan esterase (AnAXE) from Aspergillus nidulans, and active forms of both AnAXE and AnAXE-CtCBM3 were produced in Pichia pastoris. CtCBM3 fusion had negligible impact on the thermostability or regioselectivity of AnAXE; activities towards acetylated corncob xylan, 4-methylumbelliferyl acetate, p-nitrophenyl acetate, and cellobiose octaacetate were also unchanged. By contrast, the activity of AnAXE-CtCBM3 on cellulose acetate increased by two to four times over 24 h, with greater differences observed at earlier time points. Binding studies using microcrystalline cellulose (Avicel) and a commercial source of cellulose acetate confirmed functional production of the CtCBM3 domain; affinity gel electrophoresis using acetylated xylan also verified the selectivity of CtCBM3 binding to cellulose. Notably, gains in enzyme activity on cellulose acetate appeared to exceed gains in substrate binding, suggesting that fusion to CtCBM3 increases functional associations between the enzyme and insoluble, high molecular weight cellulosic substrates.

  9. Rapid analytical and preparative isolation of functional endosomes by free flow electrophoresis

    PubMed Central

    1987-01-01

    Endosomes are prelysosomal organelles that serve as an intracellular site for the sorting, distribution, and processing of receptors, ligands, fluid phase components, and membrane proteins internalized by endocytosis. Whereas the overall functions of endosomes are increasingly understood, little is known about endosome structure, composition, or biogenesis. In this paper, we describe a rapid procedure that permits analytical and preparative isolation of endosomes from a variety of tissue culture cells. The procedure relies on a combination of density gradient centrifugation and free flow electrophoresis. It yields a fraction of highly purified, functionally intact organelles. As markers for endosomes in Chinese hamster ovary cells, we used endocytosed horseradish peroxidase, FITC-conjugated dextran, and [35S]methionine-labeled Semliki Forest virus. Total postnuclear supernatants, crude microsomal pellets, or partially purified Golgi fractions were subjected to free flow electrophoresis. Endosomes and lysosomes migrated together as a single anodally deflected peak separated from most other organelles (plasma membrane, mitochondria, endoplasmic reticulum, and Golgi). The endosomes and lysosomes were then resolved by centrifugation in Percoll density gradients. Endosomes prepared in this way were enriched up to 70-fold relative to the initial homogenate and were still capable of ATP- dependent acidification. By electron microscopy, the isolated organelles were found to consist of electron lucent vacuoles and tubules, many of which could be shown to contain an endocytic tracer (e.g., horseradish peroxidase). SDS PAGE analysis of integral and peripheral membrane proteins (separated from each other by condensation in Triton X-114) revealed a unique and restricted subset of proteins when compared with lysosomes, the unshifted free flow electrophoresis peak, and total cell protein. Altogether, the purification procedure takes 5-6 h and yields amounts of endosomes (150

  10. Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots

    DOEpatents

    Zhang, Jian-Shi; Giometti, C.S.; Tollaksen, S.L.

    1987-09-04

    After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a dc power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. 8 figs.

  11. Recent advances in amino acid analysis by capillary electrophoresis.

    PubMed

    Poinsot, Véréna; Carpéné, Marie-Anne; Bouajila, Jalloul; Gavard, Pierre; Feurer, Bernard; Couderc, François

    2012-01-01

    This paper describes the most important articles that have been published on amino acid analysis using CE during the period from June 2009 to May 2011 and follows the format of the previous articles of Smith (Electrophoresis 1999, 20, 3078-3083), Prata et al. (Electrophoresis 2001, 22, 4129-4138) and Poinsot et al. (Electrophoresis 2003, 24, 4047-4062; Electrophoresis 2006, 27, 176-194; Electrophoresis 2008, 29, 207-223; Electrophoresis 2010, 31, 105-121). We present new developments in amino acid analysis with CE, which are reported describing the use of lasers or light emitting diodes for fluorescence detection, conductimetry electrochemiluminescence detectors, mass spectrometry applications, and lab-on-a-chip applications using CE. In addition, we describe articles concerning clinical studies and neurochemical applications of these techniques.

  12. Putative ABC transporter responsible for acetic acid resistance in Acetobacter aceti.

    PubMed

    Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

    2006-01-01

    Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. The aatA mutation with an insertion of the neomycin resistance gene within the aatA coding region showed reduced resistance to acetic acid, formic acid, propionic acid, and lactic acid, whereas the aatA mutation exerted no effects on resistance to various drugs, growth at low pH (adjusted with HCl), assimilation of acetic acid, or resistance to citric acid. Introduction of plasmid pABC101 containing aatA under the control of the Escherichia coli lac promoter into the aatA mutant restored the defect in acetic acid resistance. In addition, pABC101 conferred acetic acid resistance on E. coli. These findings showed that AatA was a putative ABC transporter conferring acetic acid resistance on the host cell. Southern blot analysis and subsequent nucleotide sequencing predicted the presence of aatA orthologues in a variety of acetic acid bacteria belonging to the genera Acetobacter and Gluconacetobacter. The fermentation with A. aceti containing aatA on a multicopy plasmid resulted in an increase in the final yield of acetic acid.

  13. Positron scattering from vinyl acetate

    NASA Astrophysics Data System (ADS)

    Chiari, L.; Zecca, A.; Blanco, F.; García, G.; Brunger, M. J.

    2014-09-01

    Using a Beer-Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C4H6O2) in the incident positron energy range 0.15-50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1-1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of ˜2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect.

  14. Extractive fermentation of acetic acid

    SciTech Connect

    Busche, R.M.

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  15. Using capillary electrophoresis to characterize polymeric particles.

    PubMed

    Riley, Kathryn R; Liu, Sophia; Yu, Guo; Libby, Kara; Cubicciotti, Roger; Colyer, Christa L

    2016-09-01

    Capillary electrophoresis (CE) was used for the characterization of a variety of polymeric micron and sub-micron particles based on size, surface functionality, and binding properties. First, a robust capillary zone electrophoresis (CZE) method was developed for the baseline separation and quantitation of commercially available polystyrene particles with various surface modifications (including amino, carboxylate, and sulfate functional groups) and various sizes (0.2, 0.5, 1.0, and 3.0μm). The separation of DNA-templated polyacrylamide particles from untemplated particles (as used for the Ion Torrent Personal Genome Machine) was demonstrated. Finally, using the 29-base thrombin aptamer and thrombin protein as a model system, a study was undertaken to determine dissociation constants for the aptamer and protein in free solution and when the aptamer was conjugated to a particle, with the goal of better understanding how the use of solid substrates, like particles, affects selection and binding processes. Dissociation constants were determined and were found to be approximately 5-fold higher for the aptamer conjugated to a particle relative to that in free solution. PMID:27543386

  16. Gel Electrophoresis of Gold-DNA Nanoconjugates

    DOE PAGES

    Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P.; Parak, W. J.

    2007-01-01

    Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effectivemore » diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.« less

  17. Micro-injector for capillary electrophoresis.

    PubMed

    Sáiz, Jorge; Koenka, Israel Joel; García-Ruiz, Carmen; Müller, Beat; Chwalek, Thomas; Hauser, Peter C

    2015-08-01

    A novel micro-injector for capillary electrophoresis for the handling of samples with volumes down to as little as 300 nL was designed and built in our laboratory for analyses in which the available volume is a limitation. The sample is placed into a small cavity located directly in front of the separation capillary, and the injection is then carried out automatically by controlled pressurization of the chamber with compressed air. The system also allows automated flushing of the injection chamber as well as of the capillary. In a trial with a capillary electrophoresis system with contactless conductivity detector, employing a capillary of 25 μm diameter, the results showed good stability of migration times and peak areas. To illustrate the technique, the fast separation of five inorganic cations (Na(+) , K(+) , NH4 (+) , Ca(2+) , and Mg(2+) ) was set up. This could be achieved in less than 3 min, with good limits of detection (10 μM) and linear ranges (between about 10 and 1000 μM). The system was demonstrated for the determination of the inorganic cations in porewater samples of a lake sediment core.

  18. Microfabricated polymer chip for capillary gel electrophoresis.

    PubMed

    Hong, J W; Hosokawa, K; Fujii, T; Seki, M; Endo, I

    2001-01-01

    A polymer (PDMS: poly(dimethylsiloxane)) microchip for capillary gel electrophoresis that can separate different sizes of DNA molecules in a small experimental scale is presented. This microchip can be easily produced by a simple PDMS molding method against a microfabricated master without the use of elaborate bonding processes. This PDMS microchip could be used as a single use device unlike conventional microchips made of glass, quartz or silicon. The capillary channel on the chip was partially filled with agarose gel that can enhance separation resolution of different sizes of DNA molecules and can shorten the channel length required for the separation of the sample compared to capillary electrophoresis in free-flow or polymer solution format. We discuss the optimal conditions for the gel preparation that could be used in the microchannel. DNA molecules were successfully driven by an electric field and separated to form bands in the range of 100 bp to 1 kbp in a 2.0% agarose-filled microchannel with 8 mm of effective separation length.

  19. Fractionation of mineral species by electrophoresis

    NASA Technical Reports Server (NTRS)

    Dunning, J. D.; Herren, B. J.; Tipps, R. W.; Snyder, R. S.

    1982-01-01

    The fractionation of fine-grained aggregates into their major components is a problem in many scientific areas including earth and planetary science. Electrophoresis, the transport of electrically charged particles, immersed in a suspension medium, by a direct current field (Bier, 1959), was employed in this study as a means of separating simulated lunar soil into its constituent minerals. In these tests, conducted in a static analytical cylindrical microelectrophoresis apparatus, samples of simulated lunar soil and samples of pure mineral constituents were placed in the chamber; the electrophoretic mobilities of the lunar soil and the individual mineral constituents were measured. In most of the suspension buffers employed separability was indicated, on the basis of differences in mobility, for all the constituent mineral species except ilmenite and pyroxene, which were not efficiently separable in any of the buffers. Although only a few suspension media were employed, the success of this initial study suggests that electrophoresis may be an important mineral fractionation option in fine-grained aggregate processing.

  20. Detection of glycoproteins in the Acanthamoeba plasma membrane

    SciTech Connect

    Paatero, G.I.L. ); Gahmberg, C.G. )

    1988-11-01

    In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by {sup 125}I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB{sup 3}H{sub 4} and galactose oxidase/NaB{sup 3}H{sub 4} labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M{sub r} of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ({sup 35}S)methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis.

  1. Detection of connexins in liver cells using sodiumdodecylsulfate polyacrylamide gel electrophoresis and immunoblot analysis

    PubMed Central

    Willebrords, Joost; Maes, Michaël; Yanguas, Sara Crespo; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Summary Since connexin expression is partly regulated at the protein level, immunoblot analysis represents a frequently addressed technique in the connexin research field. The present chapter describes the set-up of an immunoblot procedure, including protein extraction and quantification from biological samples, gel electrophoresis, protein transfer and immunoblotting, which is optimized for analysis of connexins in liver tissue. In essence, proteins are separated on a polyacrylamide gel using sodiumdodecylsulfate followed by transfer of proteins on a nitrocellulose membrane. The latter allows specific detection of connexins with antibodies combined with revelation through enhanced chemiluminescence. PMID:27207285

  2. Detection of Connexins in Liver Cells Using Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis and Immunoblot Analysis.

    PubMed

    Willebrords, Joost; Maes, Michaël; Yanguas, Sara Crespo; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Since connexin expression is partly regulated at the protein level, immunoblot analysis represents a frequently addressed technique in the connexin research field. The present chapter describes the setup of an immunoblot procedure, including protein extraction and quantification from biological samples, gel electrophoresis, protein transfer, and immunoblotting, which is optimized for analysis of connexins in liver tissue. In essence, proteins are separated on a polyacrylamide gel using sodium dodecyl sulfate followed by transfer of proteins on a nitrocellulose membrane. The latter allows specific detection of connexins with antibodies combined with revelation through enhanced chemiluminescence. PMID:27207285

  3. SDS-Polyacrylamide Electrophoresis and Western Blotting Applied to the Study of Asthma.

    PubMed

    García-Solaesa, Virginia; Abad, Sara Ciria

    2016-01-01

    Western blotting is used to analyze proteins after being separated by electrophoresis and subsequently electro-transferred to a membrane. Once immobilized, a specific protein can be identified through its reaction with a labeled antibody or antigen. It is a methodology commonly used in biomedical research such as asthma studies, to assess the pathways of inflammatory mediators involved in the disease.Here, we describe an example of western blotting to determine the factors involved in asthma. In this chapter, the methodology of western blotting is reviewed, paying attention on potential problems and giving interesting recommendations. PMID:27300534

  4. Aurantiamide acetate suppresses the growth of malignant gliomas in vitro and in vivo by inhibiting autophagic flux

    PubMed Central

    Yang, Yi; Zhang, Li-hui; Yang, Bing-xian; Tian, Jin-kui; Zhang, Lin

    2015-01-01

    We aim to investigate the effect of aurantiamide acetate isolated from the aerial parts of Clematis terniflora DC against gliomas. Human malignant glioma U87 and U251 cells were incubated with different concentrations (0–100 μM) of aurantiamide acetate. Aurantiamide acetate greatly decreased the cell viability in a dose- and time-dependent manner. It induced moderate mitochondrial fragmentation and the loss of mitochondrial membrane potential. No significant difference was found in the alternation of other intracellular organelles, although F-actin structure was slightly disturbed. Apparent ultrastructure alternation with increased autophagosome and autolysosome accumulation was observed in aurantiamide acetate-treated cells. The expression of LC3-II was greatly up-regulated in cells exposed to aurantiamide acetate (P < 0.05 compared with control). The cytoplasmic accumulation of autophagosomes and autolysosomes induced by aurantiamide acetate treatment was confirmed by fluorescent reporter protein labelling. Administration of chloroquine (CQ), which inhibits the fusion step of autophagosomes, further increased the accumulation of autophagosomes in the cytoplasm of U87 cells. Autophagy inhibition by 3-methyladenine, Bafilomycin A1 or CQ had no influence on aurantiamide acetate-induced cytotoxicity, whereas autophagy stimulator rapamycin significantly suppressed aurantiamide acetate-induced cell death. The anti-tumour effects of aurantiamide acetate were further evaluated in tumour-bearing nude mice. Intratumoural injection of aurantiamide acetate obviously suppressed tumour growth, and increased number of autophagic vacuoles was observed in tumour tissues of animals receiving aurantiamide acetate. Our findings suggest that aurantiamide acetate may suppress the growth of malignant gliomas by blocking autophagic flux. PMID:25704599

  5. Recent advances in microchip electrophoresis for amino acid analysis.

    PubMed

    Ou, Gaozhi; Feng, Xiaojun; Du, Wei; Liu, Xin; Liu, Bi-Feng

    2013-10-01

    With the maturation of microfluidic technologies, microchip electrophoresis has been widely employed for amino acid analysis owing to its advantages of low sample consumption, reduced analysis time, high throughput, and potential for integration and automation. In this article, we review the recent progress in amino acid analysis using microchip electrophoresis during the period from 2007 to 2012. Innovations in microchip materials, surface modification, sample introduction, microchip electrophoresis, and detection methods are documented, as well as nascent applications of amino acid analysis in single-cell analysis, microdialysis sampling, food analysis, and extraterrestrial exploration. Without doubt, more applications of microchip electrophoresis in amino acid analysis may be expected soon.

  6. Recent advances in microchip electrophoresis for amino acid analysis.

    PubMed

    Ou, Gaozhi; Feng, Xiaojun; Du, Wei; Liu, Xin; Liu, Bi-Feng

    2013-10-01

    With the maturation of microfluidic technologies, microchip electrophoresis has been widely employed for amino acid analysis owing to its advantages of low sample consumption, reduced analysis time, high throughput, and potential for integration and automation. In this article, we review the recent progress in amino acid analysis using microchip electrophoresis during the period from 2007 to 2012. Innovations in microchip materials, surface modification, sample introduction, microchip electrophoresis, and detection methods are documented, as well as nascent applications of amino acid analysis in single-cell analysis, microdialysis sampling, food analysis, and extraterrestrial exploration. Without doubt, more applications of microchip electrophoresis in amino acid analysis may be expected soon. PMID:23436170

  7. Separation and determination of homologues of linear alkylbenzenesulfonates by nonaqueous capillary zone electrophoresis using alkylammonium salts in ethanol.

    PubMed

    Herrero-Martínez, J M; Simó-Alfonso, E F; Ramis-Ramos, G

    2001-06-01

    The separation of linear alkylbenzene sulfonates (LAS) by nonaqueous capillary electrophoresis (NACE) using negative polarity, and a buffer containing acetic acid and an alkylamine in nonaqueous ethanol, has been investigated. Several primary, secondary, and tertiary alkylamines with alkyl chains of different length were compared. The solutes travelled against the electroosmotic flow (EOF), and at the same time were braked by association with the alkylamine molecules or with the alkylammonium ions. The best resolution between adjacent LAS homologues (R approximately 2.1), partial isomer resolution in two peaks, and at the same time an excellent repeatability, was obtained with a small dipentylamine excess over the acetic acid. When the buffer concentration increased, resolution between the homologues increased slightly (R approximately 2.4), and a different isomer group was partially separated. A background electrolyte (BGE) containing 10 mM acetic acid and 20 mM dipentylamine to separate and quantify the homologues within 25 min is recommended. The isomer peak profile with up to three peaks can be estimated using this buffer and another one with 80 mM acetic acid and 90 mM dipentylamine. The former BGE was used to determine LAS in liquid and powder laundry detergents. The detection limit for the determination of total LAS in these products was 2.5 microg mL(-1), and the peak area and migration time interday repeatabilities were below 4.3 and 2.8%, respectively.

  8. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  9. Membrane stabilizer

    DOEpatents

    Mingenbach, W.A.

    1988-02-09

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material. 10 figs.

  10. Cytoplasmic polyhedrosis virus classification by electropherotype; validation by serological analyses and agarose gel electrophoresis.

    PubMed

    Mertens, P P; Crook, N E; Rubinstein, R; Pedley, S; Payne, C C

    1989-01-01

    Serological analyses of several different cytoplasmic polyhedrosis viruses (CPVs), including two type 1 CPVs from Bombyx mori, type 1 CPV from Dendrolimus spectabilis, type 12 CPV from Autographa gamma, type 2 CPV from Inachis io, type 5 CPV from Orgyia pseudotsugata and type 5 CPV from Heliothis armigera, demonstrated a close correlation between the antigenic properties of the polyhedrin or virus particle structural proteins and the genomic dsRNA electropherotypes. The dsRNAs of these viruses were analysed by electrophoresis in 3% and 10% polyacrylamide gels with a discontinuous Tris-HCl/Tris-glycine buffer system or by 1% agarose gel electrophoresis using a continuous Tris-acetate-EDTA buffer system. Electrophoretic analysis in agarose gels was found to be the most suitable for the classification of CPV isolates into electropherotypes, and the results obtained showed a close correlation with the observed antigenic relationships between different virus isolates. However, electrophoretic analysis in 10% polyacrylamide gels was most sensitive for the detection of intra-type variation and the presence of mixed virus isolates. PMID:2499658

  11. NUCLEAR MEMBRANES FROM MAMMALIAN LIVER

    PubMed Central

    Franke, Werner W.; Deumling, Barbara; Ermen, Baerbel; Jarasch, Ernst-Dieter; Kleinig, Hans

    1970-01-01

    Nuclear membranes were isolated from rat and pig liver by sonication of highly purified nuclear fractions and subsequent removal of adhering nucleoproteins in a high salt medium. The fractions were examined in the electron microscope by both negative staining and thin sectioning techniques and were found to consist of nuclear envelope fragments of widely varying sizes. Nuclear pore complex constituents still could frequently be recognized. The chemical composition of the nuclear membrane fractions was determined and compared with those of microsomal fractions prepared in parallel. For total nuclei as well as for nuclear membranes and microsomes, various enzyme activities were studied. The results indicate that a similarity exists between both fractions of cytomembranes, nuclear envelope, and endoplasmic reticulum, with respect to their RNA:protein ratio and their content of polar and nonpolar lipids. Both membranous fractions had many proteins in common including some membrane-bound enzymes. Activities in Mg-ATPase and the two examined cytochrome reductases were of the same order of magnitude. The content of cytochrome b5 as well as of P-450 was markedly lower in the nuclear membranes. The nuclear membranes were found to have a higher buoyant density and to be richer in protein. The glucose-6-phosphatase and Na-K-ATPase activities in the nuclear membrane fraction were very low. In the gel electrophoresis, in addition to many common protein bands, some characteristic ones for either microsomal or nuclear membranous material were detected. Significant small amounts of DNA and RNA were found to remain closely associated with the nuclear envelope fragments. Our findings indicate that nuclear and endoplasmic reticulum membranes which are known to be in morphological continuity have, besides a far-reaching similarity, some characteristic differences. PMID:4317731

  12. Separation of Peptides by Capillary Electrophoresis.

    PubMed

    Scriba, Gerhard K E

    2016-01-01

    Peptides are an important class of analytes in chemistry, biochemistry, food chemistry, as well as medical and pharmaceutical sciences including biomarker analysis in peptidomics and proteomics. As a high-resolution technique, capillary electrophoresis (CE) is well suited for the analysis of polar compounds such as peptides. In addition, CE is orthogonal to high-performance liquid chromatography (HPLC) as both techniques are based on different physicochemical separation principles. For the successful development of peptide separations by CE, operational parameters including puffer pH, buffer concentration and buffer type, applied voltage, capillary dimensions, as well as background electrolyte additives such as detergents, ion-pairing reagents, cyclodextrins, (poly)amines, and soluble polymers have to be considered and optimized. PMID:27645745

  13. Automated DNA electrophoresis, hybridization and detection

    SciTech Connect

    Zapolski, E.J.; Gersten, D.M.; Golab, T.J.; Ledley, R.S.

    1986-05-01

    A fully automated, computer controlled system for nucleic acid hybridization analysis has been devised and constructed. In practice, DNA is digested with restriction endonuclease enzyme(s) and loaded into the system by pipette; /sup 32/P-labelled nucleic acid probe(s) is loaded into the nine hybridization chambers. Instructions for all the steps in the automated process are specified by answering questions that appear on the computer screen at the start of the experiment. Subsequent steps are performed automatically. The system performs horizontal electrophoresis in agarose gel, fixed the fragments to a solid phase matrix, denatures, neutralizes, prehybridizes, hybridizes, washes, dries and detects the radioactivity according to the specifications given by the operator. The results, printed out at the end, give the positions on the matrix to which radioactivity remains hybridized following stringent washing.

  14. Capillary Electrophoresis of Mono- and Oligosaccharides.

    PubMed

    Toppazzini, Mila; Coslovi, Anna; Rossi, Marco; Flamigni, Anna; Baiutti, Edi; Campa, Cristiana

    2016-01-01

    This chapter reports an overview of the recent advances in the analysis of mono- and oligosaccharides by capillary electrophoresis (CE); furthermore, relevant reviews and research articles recently published in the field are tabulated. Additionally, pretreatments and procedures applied to uncharged and acidic carbohydrates (i.e., monosaccharides and lower oligosaccharides carrying carboxylate, sulfate, or phosphate groups) are described.Representative examples of such procedures are reported in detail, upon describing robust methodologies for the study of (1) neutral oligosaccharides derivatized by reductive amination and by formation of glycosylamines; (2) sialic acid derivatized with 2-aminoacridone, released from human serum immunoglobulin G; (3) anomeric couples of neutral glycosides separated using borate-based buffers; (4) unsaturated, underivatized oligosaccharides from lyase-treated alginate. PMID:27645743

  15. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, Richard P.; Udseth, Harold R.; Olivares, Jose A.

    1989-01-01

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5-100 KVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., .+-.2-8 KVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit.

  16. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, Richard D.; Udseth, Harold R.; Olivares, Jose A.

    1994-10-18

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5-100 KVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., .+-.2-8 KVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit.

  17. Hybrid slab-microchannel gel electrophoresis system

    DOEpatents

    Balch, J.W.; Carrano, A.V.; Davidson, J.C.; Koo, J.C.

    1998-05-05

    A hybrid slab-microchannel gel electrophoresis system is described. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate. 4 figs.

  18. Dating silk by capillary electrophoresis mass spectrometry.

    PubMed

    Moini, Mehdi; Klauenberg, Kathryn; Ballard, Mary

    2011-10-01

    A new capillary electrophoresis mass spectrometry (CE-MS) technique is introduced for age estimation of silk textiles based on amino acid racemization rates. With an L to D conversion half-life of ~2500 years for silk (B. mori) aspartic acid, the technique is capable of dating silk textiles ranging in age from several decades to a few-thousand-years-old. Analysis required only ~100 μg or less of silk fiber. Except for a 2 h acid hydrolysis at 110 °C, no other sample preparation is required. The CE-MS analysis takes ~20 min, consumes only nanoliters of the amino acid mixture, and provides both amino acid composition profiles and D/L ratios for ~11 amino acids.

  19. Novel absorption detection techniques for capillary electrophoresis

    SciTech Connect

    Xue, Y.

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  20. Applications of capillary electrophoresis in biotechnology.

    PubMed

    Lagu, A L

    1999-10-01

    Capillary electrophoresis (CE)-related techniques are increasingly being used as a matter of routine practice in the biotechnology discipline. Since recombinant DNA-derived proteins and the antisense oligonucleotides constitute a large portion of the applications of these techniques, they have been emphasized in this review. Analyses by CE of Escherichia coli-derived proteins and glycosylated proteins derived from mammalian cell cultures are summarized, as well as those of the carbohydrate chains that have been enzymatically removed from the protein. Applications of CE in the analysis of the antisense oligonucleotides for the determination of purity and the analytical studies on the metabolism of these modified oligonucleotides, by CE are reviewed. The literature mainly covers the period from 1996. PMID:10596822

  1. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, R.D.; Udseth, H.R.; Olivares, J.A.

    1994-10-18

    A system and method for analyzing molecular constituents of a composition sample include: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5--100 kVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g.,{+-}2--8 kVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit. 21 figs.

  2. High resolution detection system of capillary electrophoresis

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Wang, Li Qiang; Shi, Yan; Zheng, Hua; Lu, Zu Kang

    2007-12-01

    The capillary electrophoresis (CE) with laser induced fluorescence detection (LIFD) system was founded according to confocal theory. The 3-D adjustment of the exciting and collecting optical paths was realized. The photomultiplier tube (PMT) is used and the signals are processed by a software designed by ourselves. Under computer control, high voltage is applied to appropriate reservoirs and to inject and separate DNA samples respectively. Two fluorescent dyes Thiazole Orange (TO) and SYBR Green I were contrasted. With both of the dyes, high signals-to-noise images were obtained with the CE-LIFD system. The single-bases can be distinguished from the electrophoretogram and high resolution of DNA sample separation was obtained.

  3. Determination of enantiomeric excess by capillary electrophoresis.

    PubMed

    Blomberg, L G; Wan, H

    2000-06-01

    Capillary electrophoresis (CE) is becoming an established method for the determination of chiral trace impurities. This paper provides an overview of the state of the art of CE for such determinations. Detection limits of 0.1% impurity is widely accepted as a minimum requirement for chiral trace impurity determinations. This can be relatively easily achieved with CE. However, determination of lower concentrations requires careful optimization of the separation system. Four factors that are of particular significance for trace enantiomeric determinations: resolution, limit of detection, linear range and type of detection, are discussed. Further, the advantages and disadvantages of derivatization in this context are treated as well as the separation approach, ie., direct chiral separation or separation after the formation of diastereomers. It is concluded that the limit of impurity detection can be about 0.05% when UV detection is employed. Using laser-induced fluorescence detection, a quantitative determination at the 0.005% level is often possible.

  4. Flow structure in continuous flow electrophoresis chambers

    NASA Technical Reports Server (NTRS)

    Deiber, J. A.; Saville, D. A.

    1982-01-01

    There are at least two ways that hydrodynamic processes can limit continiuous flow electrophoresis. One arises from the sensitivity of the flow to small temerature gradients, especially at low flow rates and power levels. This sensitivity can be suppressed, at least in principle, by providing a carefully tailored, stabilizing temperature gradient in the cooling system that surrounds the flow channel. At higher power levels another limitation arises due to a restructuring of the main flow. This restructuring is caused by buoyancy, which is in turn affected by the electro-osmotic crossflow. Approximate solutions to appropriate partial differential equations have been computed by finite difference methods. One set of results is described here to illustrate the strong coupling between the structure of the main (axial) flow and the electro-osmotic flow.

  5. Combined electrophoresis-electrospray interface and method

    DOEpatents

    Smith, R.P.; Udseth, H.R.; Olivares, J.A.

    1989-12-05

    A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5--100 kVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., [+-]2--8 kVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit, or by conduction through a sheath electrode discharged in an annular sheath flow about the capillary exit. 21 figs.

  6. Two-dimensional Gel Electrophoresis (2DE)

    NASA Astrophysics Data System (ADS)

    Kłodzińska, Ewa; Buszewski, Bogusław

    The chemical compounds, which are present in the environment, increasingly cause bad effects on health. The most serious effects are tumors and various mutations at the cellular level. Such compounds, from the analytical point of view, can serve the function of biomarkers, constituting measurable changes in the organism's cells and biochemical processes occurring therein. The challenge of the twenty-first century is therefore searching for effective and reliable methods of identification of biomarkers as well as understanding bodily functions, which occur in living organisms at the molecular level. The irreplaceable tool for these examinations is proteomics, which includes both quality and quantity analysis of proteins composition, and also makes it possible to learn their functions and expressions. The success of proteomics examinations lies in the usage of innovative analytical techniques, such as electromigration technique, two-dimensional electrophoresis in polyacrylamide gel (2D PAGE), liquid chromatography, together with high resolution mass spectrometry and bio-informatical data analysis. Proteomics joins together a number of techniques used for analysis of hundreds or thousands of proteins. Its main task is not the examination of proteins inside the particular tissue but searching for the differences in the proteins' profile between bad and healthy tissues. These differences can tell us a lot regarding the cause of the sickness as well as its consequences. For instance, using the proteomics analysis it is possible to find relatively fast new biomarkers of tumor diseases, which in the future will be used for both screening and foreseeing the course of illness. In this chapter we focus on two-dimensional electrophoresis because as it seems, it may be of enormous importance when searching for biomarkers of cancer diseases.

  7. A viscosity model of polyacrylamide gel electrophoresis.

    PubMed

    Bode, H J

    1979-08-01

    In current theories of polyacrylamide gel electrophoresis, the idea prevails that molecular sieving relies on different accessibility of volume fractions and of cross-sectional area fractions (denoted "pores") to different-sized ions due to the effect of "geometric exclusion". This correlates with the assumption that all elements of a polyacrylamide network occupy fixed and unchangeable positions thus forcing colliding macro-ions to diffuse laterally in order to find an "accessible pore" and to resume motion in direction of the electrical field. However, the alternative conception would be equally well justified, i.e. the assumption that polyacrylamide chains represent smooth obstacles cleared aside under the electrokinetic pressure of a macro-ion. This explanation would even be preferable with respect to the molecular sieving effects occurring in solutions of "liquid polyacrylamide". Yet no theory exists as to describe such effects in quantitative terms. In the present article, a parameter is defined and discussed, which can be estimated by experiment, and which seems to be apt to characterize local resistivity of polymer structures against dislocation and deformation: the "fractional specific resistance". Definition of this parameter is based on the model of a "viscosity-emulsion" composed of two interpenetrating liquid compartments which are characterized by different levels of hydrodynamic friction and the spatial dimensions of which are inferred from Ogston's theory. This concept of "localized viscosity" may also serve as a link between theories of molecular sieving and of "macroscopic viscosity" of flexible polymers. The data of Morris, formerly taken as verifications of the "rigid-pore" concept, are now interpreted in terms of four factors responsible for sizediscrimination: collision frequency, duration of single contacts, size-dependent frictional force, and the extent of cooperation among fibres, due to crosslinking and to simultanous contacts of several

  8. A specialized citric acid cycle requiring succinyl-coenzyme A (CoA):acetate CoA-transferase (AarC) confers acetic acid resistance on the acidophile Acetobacter aceti.

    PubMed

    Mullins, Elwood A; Francois, Julie A; Kappock, T Joseph

    2008-07-01

    Microbes tailor macromolecules and metabolism to overcome specific environmental challenges. Acetic acid bacteria perform the aerobic oxidation of ethanol to acetic acid and are generally resistant to high levels of these two membrane-permeable poisons. The citric acid cycle (CAC) is linked to acetic acid resistance in Acetobacter aceti by several observations, among them the oxidation of acetate to CO2 by highly resistant acetic acid bacteria and the previously unexplained role of A. aceti citrate synthase (AarA) in acetic acid resistance at a low pH. Here we assign specific biochemical roles to the other components of the A. aceti strain 1023 aarABC region. AarC is succinyl-coenzyme A (CoA):acetate CoA-transferase, which replaces succinyl-CoA synthetase in a variant CAC. This new bypass appears to reduce metabolic demand for free CoA, reliance upon nucleotide pools, and the likely effect of variable cytoplasmic pH upon CAC flux. The putative aarB gene is reassigned to SixA, a known activator of CAC flux. Carbon overflow pathways are triggered in many bacteria during metabolic limitation, which typically leads to the production and diffusive loss of acetate. Since acetate overflow is not feasible for A. aceti, a CO(2) loss strategy that allows acetic acid removal without substrate-level (de)phosphorylation may instead be employed. All three aar genes, therefore, support flux through a complete but unorthodox CAC that is needed to lower cytoplasmic acetate levels.

  9. Cellulose Acetate-Poly(N-isopropylacrylamide)-Based Functional Surfaces with Temperature-Triggered Switchable Wettability.

    PubMed

    Ganesh, V Anand; Ranganath, Anupama Sargur; Sridhar, Radhakrishnan; Raut, Hemant Kumar; Jayaraman, Sundaramurthy; Sahay, Rahul; Ramakrishna, Seeram; Baji, Avinash

    2015-07-01

    Temperature-triggered switchable nanofibrous membranes are successfully fabricated from a mixture of cellulose acetate (CA) and poly(N-isopropylacrylamide) (PNIPAM) by employing a single-step direct electrospinning process. These hybrid CA-PNIPAM membranes demonstrate the ability to switch between two wetting states viz. superhydrophilic to highly hydrophobic states upon increasing the temperature. At room temperature (23 °C) CA-PNIPAM nanofibrous membranes exhibit superhydrophilicity, while at elevated temperature (40 °C) the membranes demonstrate hydrophobicity with a static water contact angle greater than 130°. Furthermore, the results here demonstrate that the degree of hydrophobicity of the membranes can be controlled by adjusting the ratio of PNIPAM in the CA-PNIPAM mixture.

  10. Inexpensive and Safe DNA Gel Electrophoresis Using Household Materials

    ERIC Educational Resources Information Center

    Ens, S.; Olson, A. B.; Dudley, C.; Ross, N. D., III; Siddiqi, A. A.; Umoh, K. M.; Schneegurt, M. A.

    2012-01-01

    Gel electrophoresis is the single most important molecular biology technique and it is central to life sciences research, but it is often too expensive for the secondary science classroom or homeschoolers. A simple safe low-cost procedure is described here that uses household materials to construct and run DNA gel electrophoresis. Plastic…

  11. [Analysis of ribosomes by polyacrylamide gel electrophoresis (author's transl)].

    PubMed

    Ledoigt, G; Curgy, J J; Stevens, B J; André, J

    1975-10-01

    Ribosomal polymers, monomers and subunits from several eukaryotes and prokaryotes were isolated and analyzed by polyacrylamide gel electrophoresis. Extraction of RNA from ribosomal particles after their migration in a polyacrylamide gel, analyses by sedimentation in sucrose gradients and observations in the electron microscope were carried out in parallel. Attention was directed to the reproducibility, the precision and the limitations of the electrophoresis technique.

  12. Gel Electrophoresis on a Budget to Dye for

    ERIC Educational Resources Information Center

    Yu, Julie H.

    2010-01-01

    Gel electrophoresis is one of the most important tools used in molecular biology and has facilitated the entire field of genetic engineering by enabling the separation of nucleic acids and proteins. However, commercial electrophoresis kits can cost up to $800 for each setup, which is cost prohibitive for most classroom budgets. This article…

  13. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrophoresis apparatus for clinical use. 862.2485 Section 862.2485 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An...

  14. 21 CFR 862.2485 - Electrophoresis apparatus for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrophoresis apparatus for clinical use. 862.2485 Section 862.2485 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Instruments § 862.2485 Electrophoresis apparatus for clinical use. (a) Identification. An...

  15. Immobilized Metal Affinity Electrophoresis: A Novel Method of Capturing Phosphoproteins by Electrophoresis

    PubMed Central

    Lee, Bao-Shiang; Lasanthi, G.D.; Jayathilaka, P.; Huang, Jin-Sheng; Gupta, Shalini

    2008-01-01

    An immobilized metal affinity electrophoresis (IMAEP) method is described here. In this method, metal ions are immobilized in a native polyacrylamide gel to capture phosphoproteins. The capture of phosphoproteins by IMAEP is demonstrated with immobilized metals like iron, aluminum, manganese, or titanium. In the case studies, phosphoproteins α-casein, β-casein, and phosvitin are successfully extracted from a protein mixture by IMAEP. PMID:19137092

  16. Acetate in mixotrophic growth medium affects photosystem II in Chlamydomonas reinhardtii and protects against photoinhibition.

    PubMed

    Roach, Thomas; Sedoud, Arezki; Krieger-Liszkay, Anja

    2013-10-01

    Chlamydomonas reinhardtii is a photoautotrophic green alga, which can be grown mixotrophically in acetate-supplemented media (Tris-acetate-phosphate). We show that acetate has a direct effect on photosystem II (PSII). As a consequence, Tris-acetate-phosphate-grown mixotrophic C. reinhardtii cultures are less susceptible to photoinhibition than photoautotrophic cultures when subjected to high light. Spin-trapping electron paramagnetic resonance spectroscopy showed that thylakoids from mixotrophic C. reinhardtii produced less (1)O2 than those from photoautotrophic cultures. The same was observed in vivo by measuring DanePy oxalate fluorescence quenching. Photoinhibition can be induced by the production of (1)O2 originating from charge recombination events in photosystem II, which are governed by the midpoint potentials (Em) of the quinone electron acceptors. Thermoluminescence indicated that the Em of the primary quinone acceptor (QA/QA(-)) of mixotrophic cells was stabilised while the Em of the secondary quinone acceptor (QB/QB(-)) was destabilised, therefore favouring direct non-radiative charge recombination events that do not lead to (1)O2 production. Acetate treatment of photosystem II-enriched membrane fragments from spinach led to the same thermoluminescence shifts as observed in C. reinhardtii, showing that acetate exhibits a direct effect on photosystem II independent from the metabolic state of a cell. A change in the environment of the non-heme iron of acetate-treated photosystem II particles was detected by low temperature electron paramagnetic resonance spectroscopy. We hypothesise that acetate replaces the bicarbonate associated to the non-heme iron and changes the environment of QA and QB affecting photosystem II charge recombination events and photoinhibition.

  17. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    PubMed

    Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large

  18. Rapid simultaneous determination of organic acids, free amino acids, and lactose in cheese by capillary electrophoresis.

    PubMed

    Izco, J M; Tormo, M; Jiménez-Flores, R

    2002-09-01

    A capillary electrophoresis (CE) method for the simultaneous separation of 11 metabolically important organic acids (oxalic, formic, citric, succinic, orotic, uric, acetic, pyruvic, propionic, lactic, and butyric), 10 amino acids (Asp, Glu, Tyr, Gly, Ala, Ser, Leu, Phe, Lys, and Trp), and lactose has been optimized, validated, and tested in dairy products. Repeatability and linearity were calculated for each compound, with detection limit values as low as 0.2 x 10(-2) mM for citric acid and Gly. The method was applied to analyze yogurt and different varieties of commercial cheeses. This method yielded specific CE patterns for different varieties of cheese. Also, it has been shown to be sensitive enough to measure small changes in composition of some of those compounds in fresh cheese stored under accelerated ripening conditions for 2 d at 32 degrees C (e.g., from 1728.3 +/- 45.0 to 1166.7 +/- 4.5 mg/100 g of DM in the case of lactose, or from 23.5 +/- 0.6 to 76.8 +/- 16.7 mg/100 g of DM in the case of acetic acid).

  19. Membrane tension and membrane fusion.

    PubMed

    Kozlov, Michael M; Chernomordik, Leonid V

    2015-08-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually large membrane tensions or, alternatively, low line tensions of the pore resulting from accumulation in the pore rim of membrane-bending proteins. Increase of the inter-membrane distance facilitates the reaction. PMID:26282924

  20. Conversion to eslicarbazepine acetate monotherapy

    PubMed Central

    French, Jacqueline; Jacobson, Mercedes P.; Pazdera, Ladislav; Gough, Mallory; Cheng, Hailong; Grinnell, Todd; Blum, David

    2016-01-01

    Objective: To assess the efficacy and safety of eslicarbazepine acetate (ESL) monotherapy. Methods: This post hoc pooled analysis of 2 randomized double-blind studies (093-045 and -046) included adults with partial-onset seizures medically uncontrolled by 1 or 2 antiepileptic drugs (AEDs). Following the baseline period (8 weeks), eligible patients were randomized 2:1 to receive ESL 1,600 mg or 1,200 mg once daily for 18 weeks; the primary endpoint was study exit by meeting predefined exit criteria (signifying worsening seizure control). In each study, treatment was considered effective if the upper 95% confidence limit for exit rate was lower than the historical control threshold (65.3%). Results: Pooled exit rates were as follows: ESL 1,600 mg = 20.6% (95% confidence interval: 15.6%–26.8%); ESL 1,200 mg = 30.8% (23.0%–40.5%). Use of 2 baseline AEDs or rescue medication, US location, epilepsy duration ≥20 years, and higher maximum baseline seizure frequency were associated with higher exit risks. Median percent reductions in standardized seizure frequency between baseline and the 18-week double-blind period were as follows: ESL 1,600 mg = 43.2%; ESL 1,200 mg = 35.7%; baseline carbamazepine use was associated with smaller reductions. Safety profiles were similar between ESL doses. Conclusions: Exit rates for ESL monotherapy (1,600 mg and 1,200 mg once daily) were lower than the historical control threshold, irrespective of baseline AED use and region, with no additional safety concerns identified. Clinical factors and location clearly influence treatment responses in conversion-to-monotherapy trials. Classification of evidence: This pooled analysis provides Class IV evidence that for adults with medically uncontrolled partial-onset seizures, ESL monotherapy is well tolerated and effective. PMID:26911639

  1. Intravitreal injection of octreotide acetate.

    PubMed

    Robertson, J E; Westra, I; Woltering, E A; Winthrop, K L; Barrie, R; O'Dorisio, T M; Holmes, D

    1997-04-01

    This study was conducted to determine the feasibility of injecting the somatostatin analogue, octreotide acetate (OA), into the vitreous cavity. Previous work suggests that octreotide effectively inhibits angiogenesis in vitro, thus its use in vivo may slow the progression of proliferative eye disease. Fifty micrograms of aqueous OA in 50 microliters aqueous solution was injected into the mid-vitreous of kitten eyes (n = 6), and OA levels were monitored over 4 days. A long-acting release form of octreotide (OA-LAR) was also injected into the mid-vitreous of rabbit eyes at doses of 0.36 (n = 16), 1.1 (n = 1), 2.1 (n = 1), 4.05 (n = 1), 8.2 (n = 1), and 36 mg (n = 3) in solution; and octreotide concentrations were measured at various time points over 42 days. OA concentrations were determined by a highly specific radioimmunoassay. Aqueous octreotide was eliminated rapidly (t1/2 = 16 hours) from the vitreous of the kitten eye, with only negligible amounts recoverable 4 days post-injection. In the long-acting form, OA in the rabbit eye reached peak levels at 28 days. By 42 days, OA levels had declined to the 14-day level. Doses of OA-LAR of 1.1 mg or less produced no gross evidence of clinical toxicity and elicited no grossly visible ocular side effects. Doses greater than 1.1 mg produced significant toxicity, including cataracts and rubeosis. The 28-day peak release for long-acting OA implies that monthly intravitreal injections could provide continual high levels of OA. Intravitreal injection of long-acting OA provides sustained, high concentrations of drug, and deserves further study as a potential treatment of proliferative eye diseases.

  2. Membrane characteristics for biological blast overpressure testing using blast simulators.

    PubMed

    Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J

    2014-01-01

    Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70–210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70–210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators. PMID:25405432

  3. Validation of STR typing by capillary electrophoresis.

    PubMed

    Moretti, T R; Baumstark, A L; Defenbaugh, D A; Keys, K M; Brown, A L; Budowle, B

    2001-05-01

    With the use of capillary electrophoresis (CE), high-resolution electrophoretic separation of short tandem repeat (STR) loci can be achieved in a semiautomated fashion. Laser-induced detection of fluorescently labeled PCR products and multicolor analysis enable the rapid generation of multilocus DNA profiles. In this study, conditions for typing PCR-amplified STR loci by capillary electrophoresis were investigated using the ABI Prism 310 Genetic Analyzer (Applied Biosystems). An internal size standard was used with each run to effectively normalize mobility differences among injections. Alleles were designated by comparison to allelic ladders that were run with each sample set. Multiple runs of allelic ladders and of amplified samples demonstrate that allele sizes were reproducible, with standard deviations typically less than 0.12 bases for fragments up to 317 bases in length (largest allele analyzed) separated in a 47 cm capillary. Therefore, 99.7% of all alleles that are the same length should fall within the measurement error window of +/- 0.36 bases. Microvariants of the tetranucleotide repeats were also accurately typed by the analytical software. Alleles differing in size by one base could be resolved in two-donor DNA mixtures in which the minor component comprised > or = 5% of the total DNA. Furthermore, the quantitative data format (i.e., peak amplitude) can in some instances assist in determining individual STR profiles in mixed samples. DNA samples from previously typed cases (typed for RFLP, AmpliType PM+DQA1, and/or D1S80) were amplified using AmpFlSTR Profiler Plus and COfiler and were evaluated using the ABI Prism 310. Most samples yielded typable results. Compared with previously determined results for other loci, there were no discrepancies as to the inclusion or exclusion of suspects or victims. CE thus provides efficient separation, resolution, sensitivity and precision, and the analytical software provides reliable genotyping of STR loci. The

  4. Fragrance material review on 3-phenylpropyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 3-phenylpropyl acetate when used as a fragrance ingredient is presented. 3-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, skin sensitization, and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  5. Fragrance material review on anisyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of anisyl acetate when used as a fragrance ingredient is presented. Anisyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for anisyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, elicitation, and phototoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  6. Fragrance material review on 4-methylbenzyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 4-methylbenzyl acetate when used as a fragrance ingredient is presented. 4-Methylbenzyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 4-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, and elicitation data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  7. Fused quartz substrates for microchip electrophoresis

    SciTech Connect

    Jacobson, S.C.; Moore, A.W.; Ramsey, J.M.

    1995-07-01

    A fused quartz microchip is fabricated to perform capillary electrophoresis of metal ions complexed with 8-hydroxyquinoline-5-sulfonic acid (HQS). The channel manifold on the quartz substrate is fabricated using standard photolithographic, etching, and deposition techniques. By incorporating a direct bonding technique during the fabrication of the microchip, the substrate and cover plate can be fused together below the melting temperature for fused quartz. To enhance the resolution for the separation, the electroosmotic flow is minimized by covalently bonding polyacrylamide to the channel walls. A separation length of 16.5 mm and separation field strength of 870 V/cm enable separations to be performed in {<=}15 s. By increasing the concentration of HQS from 5 mM to 20 mM, the separation efficiency improves by approximately 3 times. The low background signal from the fused quartz substrate results in mass detection limits of 85, 61, and 134 amol and concentration detection limits of 46, 57, and 30 ppb for Zn, Cd, and Al, respectively. 30 refs., 6 figs., 2 tabs.

  8. Analysis of venlafaxine by capillary zone electrophoresis.

    PubMed

    Fanali, S; Cotichini, V; Porrà, R

    1997-01-01

    Capillary electrophoresis has been used for the separation of venlafaxine and two of its impurities deriving from the synthesis process. The electrophoretic experiments were performed using background electrolytes at different pHs in the 2.5-9.2 range in order to study the effective mobilities and resolution of the three examined compounds. The optimum experimental conditions for the baseline resolution of the three analytes was found at pH 6.5. Very good repeatability for both migration time and corrected peak areas was achieved. The calibration curve was studied for venlafaxine (concentration range 26-224 micrograms/mL), and the plot of the peak area ratio (sample/internal standard [IS]) versus venlafaxine concentration was linear with a correlation coefficient of 0.9991. The effect of different cyclodextrins (CDs), namely, gamma-cyclodextrin (gamma-CD), hydroxypropyl-beta-CD (HP-beta-CD), and alpha-cyclodextrin (alpha-CD), on effective mobility and enantiomeric resolution (R) of venlafaxine (Wy45030) and its impurities (imp1 and imp2) was studied at different pHs, and the best results were obtained at pH 9.2. Venlafaxine was baseline resolved in its enantiomers using gamma-CD or HP-beta-CD, while imp1 (Wy45494) was baseline resolved using alpha-CD.

  9. Injector-concentrator electrodes for microchannel electrophoresis

    DOEpatents

    Swierkowski, Stefan P.

    2003-05-06

    An input port geometry, with injector-concentrator electrodes, for planar microchannel array for electrophoresis. This input port geometry enables efficient extraction and injection of the DNA sample from a single input port. The geometry, which utilizes injector-concentrator electrodes, allows simultaneous concentration, in different channels, of the sample into a longitudinally narrow strip just before releasing it for a run with enhanced injection spatial resolution, and time resolution. Optional multiple electrodes, at a different bias than the concentrator electrodes, may be used to discriminate against sample impurity ions. Electrode passivation can be utilized to prevent electrolysis. An additional electrode in or on the input hole can better define the initial loading. The injector-concentrator electrodes are positioned so that they cross the drift channel in a narrow strip at the bond plane between the top and bottom plates of the instrument and are located close to the inlet hole. The optional sample purification electrodes are located at a greater distance from the input hole than the injector-concentrate electrodes.

  10. Robotics in biomedical chromatography and electrophoresis.

    PubMed

    Fouda, H G

    1989-08-11

    The ideal laboratory robot can be viewed as "an indefatigable assistant capable of working continuously for 24 h a day with constant efficiency". The development of a system approaching that promise requires considerable skill and time commitment, a thorough understanding of the capabilities and limitations of the robot and its specialized modules and an intimate knowledge of the functions to be automated. The robot need not emulate every manual step. Effective substitutes for difficult steps must be devised. The future of laboratory robots depends not only on technological advances in other fields, but also on the skill and creativity of chromatographers and other scientists. The robot has been applied to automate numerous biomedical chromatography and electrophoresis methods. The quality of its data can approach, and in some cases exceed, that of manual methods. Maintaining high data quality during continuous operation requires frequent maintenance and validation. Well designed robotic systems can yield substantial increase in the laboratory productivity without a corresponding increase in manpower. They can free skilled personnel from mundane tasks and can enhance the safety of the laboratory environment. The integration of robotics, chromatography systems and laboratory information management systems permits full automation and affords opportunities for unattended method development and for future incorporation of artificial intelligence techniques and the evolution of expert systems. Finally, humanoid attributes aside, robotic utilization in the laboratory should not be an end in itself. The robot is a useful tool that should be utilized only when it is prudent and cost-effective to do so.

  11. Integrated polymerase chain reaction/electrophoresis instrument

    DOEpatents

    Andresen, Brian D.

    2000-01-01

    A new approach and instrument for field identification of micro-organisms and DNA fragments using a small and disposable device containing integrated polymerase chain reaction (PCR) enzymatic reaction wells, attached capillary electrophoresis (CE) channels, detectors, and read-out all on/in a small hand-held package. The analysis instrument may be made inexpensively, for example, of plastic, and thus is disposable, which minimizes cross contamination and the potential for false positive identification between samples. In addition, it is designed for multiple users with individual applications. The integrated PCR/CE is manufactured by the PCR well and CE channels are "stamped" into plastic depressions where conductive coatings are made in the wells and ends of the CE microchannels to carry voltage and current to heat the PCR reaction mixtures and simultaneously draw DNA bands up the CE channels. Light is transmitted through the instrument at appropriate points and detects PCR bands and identifies DNA fragments by size (retention time) and quantifies each by the amount of light generated as each phototransistor positioned below each CE channel detects a passing band. The instrument is so compact that at least 100 PCR/CE reactions/analyses can be performed easily on one detection device.

  12. Capillary electrophoresis coupled to biosensor detection.

    PubMed

    Bossi, A; Piletsky, S A; Righetti, P G; Turner, A P

    2000-09-15

    The present review highlights some modern aspects of biosensor revelation, a detection method which has already found a large number of applications in healthcare, food industry and environmental analysis. First, the concept of bio-recognition, which is at the heart of biosensor technology, is discussed, with emphasis on host-guest-like recognition mechanisms. This detection device has been successfully coupled, in its first applications, to chromatographic columns, which allow a high resolution of complex mixtures of analytes prior to interaction with the biosensing unit. The properties of the transducing elements, which should generate a signal (e.g., electrochemical, thermal, acoustic, optical) of proper intensity and of relative fast rise, are additionally evaluated and discussed. The review then focuses on potential applications of biosensing units in capillary electrophoresis (CE) devices. CE appears to be an excellent separation methodology to be coupled to biosensor detection, since it is based on miniaturized electrophoretic chambers, fast analysis times, complete automation in sample handling and data treatment and requires extremely small sample volumes. Although only a few applications of CE-based biosensors have been described up to the present, it is anticipated that this hyphenated technique could have a considerable expansion in the coming years.

  13. Active airborne contamination control using electrophoresis

    SciTech Connect

    Veatch, B.D.

    1994-06-01

    In spite of our best efforts, radioactive airborne contamination continues to be a formidable problem at many of the Department of Energy (DOE) weapons complex sites. For workers that must enter areas with high levels of airborne contamination, personnel protective equipment (PPE) can become highly restrictive, greatly diminishing productivity. Rather than require even more restrictive PPE for personnel in some situations, the Rocky Flats Plant (RFP) is actively researching and developing methods to aggressively combat airborne contamination hazards using electrophoretic technology. With appropriate equipment, airborne particulates can be effectively removed and collected for disposal in one simple process. The equipment needed to implement electrophoresis is relatively inexpensive, highly reliable, and very compact. Once airborne contamination levels are reduced, less PPE is required and a significant cost savings may be realized through decreased waste and maximized productivity. Preliminary ``cold,`` or non-radioactive, testing results at the RFP have shown the technology to be effective on a reasonable scale, with several potential benefits and an abundance of applications.

  14. Impoundment liner repair by electrophoresis of clay

    SciTech Connect

    Yeung, A.T.; Corapcioglu, M.Y.; Stallard, W.M.; Chung, M.

    1997-10-01

    Electrophoresis of clay particles from dilute suspensions is an innovative technology to seal leaks in operating surface impoundments that does not require removal of impoundment contents, exposure of workers to contaminants, or prior knowledge of the leak locations. A suspension of clay particles is added to the impoundment liquid. A cathode (negative electrode) is placed inside and an anode (positive electrode) is placed outside the leaking impoundment. A direct current (DC) electric field is imposed externally across the geomembrane liner through the leaks. The clay particles migrate to the leaks under the influence of the imposed electric field to form a clay cake seal. The results of laboratory experiments to evaluate the use of a DC electric field to direct migration of clay particles into a leak and the hydraulic integrity of the resulting seal are presented in this paper. The effects of clay type, clay particle concentration in suspension, size of leak, and electric field strength on the migration of clay particles and process of cake formation are evaluated. The sealing effectiveness and internal structure of the resulting clay cakes are examined by hydraulic conductivity measurements and nuclear magnetic resonance imaging. Electrophoretic mobilities of bentonite particles in different chemical environments were also measured to evaluate the feasibility of the technology in practical situations.

  15. Differentiation of enantiomers by capillary electrophoresis.

    PubMed

    Scriba, Gerhard K E

    2013-01-01

    Capillary electrophoresis (CE) has matured to one of the major liquid phase enantiodifferentiation techniques since the first report in 1985. This can be primarily attributed to the flexibility as well as the various modes available including electrokinetic chromatography (EKC), micellar electrokinetic chromatography (MEKC), and microemulsion electrokinetic chromatography (MEEKC). In contrast to chromatographic techniques, the chiral selector is mobile in the background electrolyte. Furthermore, a large variety of chiral selectors are available that can be easily combined in the same separation system. In addition, the migration order of the enantiomers can be adjusted by a number of approaches. In CE enantiodifferentiations the separation principle is comparable to chromatography while the principle of the movement of the analytes in the capillary is based on electrophoretic phenomena. The present chapter will focus on mechanistic aspects of CE enantioseparations including enantiomer migration order and the current understanding of selector-selectand structures. Selected examples of the basic enantioseparation modes EKC, MEKC, and MEEKC will be discussed. PMID:23666080

  16. Acetate limitation and nitrite accumulation during denitrification

    SciTech Connect

    Oh, J.; Silverstein, J.

    1999-03-01

    Nitrite accumulated in denitrifying activated sludge mixed liquor when the carbon and electron source, acetate, was limited. If acetate was added to obtain a carbon-to-nitrogen (C:N) ratio in the range of 2:1 to 3:1, nitrate was completely consumed at the same rate with no nitrite accumulation, indicating that nitrate concentration controlled the respiration rate as long as sufficient substrate was present. However, when acetate was reduced to a C:N ratio of 1:1, while nitrate continued to be consumed, > 50% of the initial nitrate-nitrogen accumulated as nitrite and 29% persisted as nitrite throughout an endogenous denitrification period of 8--9 h. While nitrite accumulated during acetate-limited denitrification, the specific nitrate reduction rate increased significantly compared with the rate when excess acetate was provided as follows: 0.034 mg-NO{sub 3}-N/mg-mixed liquid volatile suspended solids/h versus 0.023 mg-NO{sub 3}-N/mg-mixed liquid volatile suspended solids/h, respective. This may be explained by nitrate respiration out-competing nitrite respiration for limited acetate electrons. Complete restoration of balanced denitrification and elimination of nitrite accumulation during denitrification required several weeks after the C:N ratio was increased back to 2:1.

  17. A centrifugal method for the evaluation of polymer membranes for reverse osmosis

    NASA Technical Reports Server (NTRS)

    Hollahan, J. R.; Wydeven, T.; Mccullough, R. P.

    1973-01-01

    A rapid and simple method employing the laboratory centrifuge shows promise for evaluation of membrane performance during reverse osmosis. Results are presented for cellulose acetate membranes for rejection of salt and urea dissolved solids. Implications of the study are to rapid screening of membrane performance, use in laboratories with limited facilities, and possible space waste water purification.

  18. Membrane distillation

    NASA Astrophysics Data System (ADS)

    Bryk, Mikhail T.; Nigmatullin, R. R.

    1994-12-01

    Studies in the field of membrane distillation are analysed. A critical analysis of the theoretical and experimental investigations of membrane distillation is presented. Attention is concentrated on the mechanism of mass transfer and the influence of various external factors on the process characteristics. Questions concerning the creation of modules and apparatus for membrane distillation and aspects of the practical employment of such distillation in order to obtain pure water, for the purification of waste water, and for the concentration of technological solutions in various branches of industry are considered quite fully. The advantages and disadvantages of membrane distillation compared with other membrane methods are analysed. The bibliography includes 97 references.

  19. Extended length microchannels for high density high throughput electrophoresis systems

    DOEpatents

    Davidson, James C.; Balch, Joseph W.

    2000-01-01

    High throughput electrophoresis systems which provide extended well-to-read distances on smaller substrates, thus compacting the overall systems. The electrophoresis systems utilize a high density array of microchannels for electrophoresis analysis with extended read lengths. The microchannel geometry can be used individually or in conjunction to increase the effective length of a separation channel while minimally impacting the packing density of channels. One embodiment uses sinusoidal microchannels, while another embodiment uses plural microchannels interconnected by a via. The extended channel systems can be applied to virtually any type of channel confined chromatography.

  20. Indium acetate toxicity in male reproductive system in rats.

    PubMed

    Lee, Kuo-Hsin; Chen, Hsiu-Ling; Leung, Chung-Man; Chen, Hsin-Pao; Hsu, Ping-Chi

    2016-01-01

    Indium, a rare earth metal characterized by high plasticity, corrosion resistance, and a low melting point, is widely used in the electronics industry, but has been reported to be an environmental pollutant and a health hazard. We designed a study to investigate the effects of subacute exposure of indium compounds on male reproductive function. Twelve-week old male Sprague-Dawley rats were randomly divided into test and control groups, and received weekly intraperitoneal injections of indium acetate (1.5 mg/kg body weight) and normal saline, respectively, for 8 weeks. Serum indium levels, cauda epididymal sperm count, motility, morphology, chromatin DNA structure, mitochondrial membrane potential, oxidative stress, and testis DNA content were investigated. The indium acetate-treated group showed significant reproductive toxicity, as well as an increased percentage of sperm morphology abnormality, chromatin integrity damage, and superoxide anion generation. Furthermore, positive correlations among sperm morphology abnormalities, chromatin DNA damage, and superoxide anion generation were also noted. The results of this study demonstrated the toxic effect of subacute low-dose indium exposure during the period of sexual maturation on male reproductive function in adulthood, through an increase in oxidative stress and sperm chromatin DNA damage during spermiogenesis, in a rodent model.

  1. Distinct Effects of Sorbic Acid and Acetic Acid on the Electrophysiology and Metabolism of Bacillus subtilis

    PubMed Central

    van Beilen, J. W. A.; Teixeira de Mattos, M. J.; Hellingwerf, K. J.

    2014-01-01

    Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness. PMID:25038097

  2. Membrane Extraction for Detoxification of Biomass Hydrolysates

    SciTech Connect

    Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.

    2012-05-01

    Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

  3. Free zone electrophoresis simulation of static column electrophoresis in microgravity on shuttle flight STS-3

    NASA Technical Reports Server (NTRS)

    Todd, P. W.; Hjerten, S.

    1985-01-01

    Experiments were designed to replicate, as closely as possible in 1-G, the conditions of the STS-3 red blood cell (RBC) experiments. Free zone electrophoresis was the method of choice, since it minimizes the role of gravity in cell migration. The physical conditions of the STS-3 experiments were used, and human and rabbit RBC's fixed by the same method were the test particles. The effects of cell concentration, electroosmotic mobility, and sample composition were tested in order to seek explanations for the STS-3 results and to provide data on cell concentration effects for future zero-G separation on the continuous-flow zero-G electrophoretics separator.

  4. Developmental effects of lead acetate on the chick embryo metanephros.

    PubMed

    Errede, M; Elia, G; Bertossi, M; Mulas, M L; Riva, A; Virgintino, D; Benagiano, V; Girolamo, F; Roncali, L; Ambrosi, L

    2001-07-01

    The developmental effects of lead acetate were studied in the chick embryo metanephros, the third renal rudiment that acquires morphological characteristics of functioning kidney already during the prenatal life. Lead exposure was obtained by applying a lead acetate solution on the chick embryo chorioallantoic membrane at the days 9, 10 and 11 of incubation. Quantitative evaluation of the lead concentration assessed by furnace atomic absorption spectrophotometry at the days 14 and 21 of incubation demonstrated metal presence both in the chorioallantoic membrane (CAM) and in metanephros (MN). The lead concentration was higher in CAM than in MN; the metal amount was similar in the CAM of 14 and 21 day embryos, but significantly higher in the 14day embryo MN than in the 21 day embryo MN. Morphological observations on metanephros tissue of control and lead-treated embryos were performed under light, electron transmission and electron scanning microscopes. Peculiar attention was devoted to the expression of the junctional protein connexin 43, the major component of the gap junctions in the renal cells. The results indicated that lead treatment does not intervene in the general differentiation of the metanephric nephrons. The lead is reabsorbed by the proximal tubule cells that are engulfed by endocytotic vacuoles and metal deposits and show long term degenerative changes. Expression of Cx43 protein and ultrastructure of gap junctions between proximal tubule cells appeared to be unchanged. The morphological aspects of the MN corpuscles and tubules agree with the suggestion of a lead cytotoxic effect but do not corroborate, at least in this experimental model, the view of primary damage exerted by lead on the gap junctions of the renal epithelial cells.

  5. Radiation effects on bovine taste bud membranes

    SciTech Connect

    Shatzman, A.R.; Mossman, K.L.

    1982-11-01

    In order to investigate the mechanisms of radiation-induced taste loss, the effects of radiation on preparations of enriched bovine taste bud membranes were studied. Taste buds containing circumvallate papilae, and surrounding control epithelial tissues devoid of taste buds, were obtained from steers and given radiation doses of 0-7000 cGy (rad). Tissue fractions were isolated into membrane-enriched and heterogeneous components using differential and sucrose gradient centrifugation of tissue homogenates. The yield of membranes, as measured by protein content in the buoyant membrane-enriched fractions, was reduced in quantity with increasing radiation dose. The relation between radiation dose and membrane quantity in membrane-enriched fractions could be fit by a simple exponential model with taste bud-derived membranes twice as radiosensitive as membranes from control epithelial tissue. Binding of sucrose, sodium, and acetate and fluoride stimulation of adenylate cyclase were nearly identical in both irradiated and nonirradiated intact membranes. Radiation had no effect on fractions of heterogeneous components. While it is not clear what changes are occurring in enriched taste cell membranes, damage to membranes may play an important role in the taste loss observed in patients following radiotherapy.

  6. Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes.

    PubMed

    Yüksel, Suna; Kabay, Nalan; Yüksel, Mithat

    2013-12-15

    The removal of an endocrine disrupting compound, bisphenol A (BPA), from model solutions by selected nanofiltration (NF) and reverse osmosis (RO) membranes was studied. The commercially available membranes NF 90, NF 270, XLE BWRO, BW 30 (Dow FilmTech), CE BWRO and AD SWRO (GE Osmonics) were used to compare their performances for BPA removal. The water permeability coefficients, rejection of BPA and permeate flux values were calculated for all membranes used. No significant changes in their BPA removal were observed for all tight polyamide based NF and RO membranes tested except for loose NF 270 membrane. The polyamide based membranes exhibited much better performance than cellulose acetate membrane for BPA removal. Almost a complete rejection (≥ 98%) for BPA was obtained with three polyamide based RO membranes (BW 30, XLE BWRO and AD SWRO). But cellulose acetate based CE BWRO membrane offered a low and variable (10-40%) rejection for BPA.

  7. Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes.

    PubMed

    Yüksel, Suna; Kabay, Nalan; Yüksel, Mithat

    2013-12-15

    The removal of an endocrine disrupting compound, bisphenol A (BPA), from model solutions by selected nanofiltration (NF) and reverse osmosis (RO) membranes was studied. The commercially available membranes NF 90, NF 270, XLE BWRO, BW 30 (Dow FilmTech), CE BWRO and AD SWRO (GE Osmonics) were used to compare their performances for BPA removal. The water permeability coefficients, rejection of BPA and permeate flux values were calculated for all membranes used. No significant changes in their BPA removal were observed for all tight polyamide based NF and RO membranes tested except for loose NF 270 membrane. The polyamide based membranes exhibited much better performance than cellulose acetate membrane for BPA removal. Almost a complete rejection (≥ 98%) for BPA was obtained with three polyamide based RO membranes (BW 30, XLE BWRO and AD SWRO). But cellulose acetate based CE BWRO membrane offered a low and variable (10-40%) rejection for BPA. PMID:23731784

  8. Electromembrane extraction and HPLC analysis of haloacetic acids and aromatic acetic acids in wastewater.

    PubMed

    Alhooshani, Khalid; Basheer, Chanbasha; Kaur, Jagjit; Gjelstad, Astrid; Rasmussen, Knut E; Pedersen-Bjergaard, Stig; Lee, Hian Kee

    2011-10-30

    For the first time, haloacetic acids and aromatic acetic acids were extracted from wastewater samples using electromembrane extraction (EME). A thin layer of toluene immobilized on the walls of a polypropylene membrane envelope served as an artificial supported liquid membrane (SLM). The haloacetic acids (HAAs) (chloroacetic acid, dichloroacetic acid, and trifluoroacetic acid) and aromatic acetic acids (phenylacetic acid and p-hydroxyphenylacetic acid) were extracted through the SLM and into an alkalized aqueous buffer solution. The buffer solution was located inside the membrane envelope. The electrical potential difference sustained over the membrane acted as the driving force for the transport of haloacetic acids into the membrane by electrokinetic migration. After extraction, the extracts were analyzed by high-performance liquid chromatography-ultraviolet detection. The detection limits were between 0.072 and 40.3 ng L(-1). The calibration plot linearity was in the range of 5 and 200 μg L(-1) while the correlation coefficients for the analytes ranged from 0.9932 to 0.9967. Relative recoveries were in the range of 87-106%. The extraction efficiency was found to be comparable to that of solid-phase extraction.

  9. Microchannel DNA Sequencing by End-Labelled Free Solution Electrophoresis

    SciTech Connect

    Barron, A.

    2005-09-29

    The further development of End-Labeled Free-Solution Electrophoresis will greatly simplify DNA separation and sequencing on microfluidic devices. The development and optimization of drag-tags is critical to the success of this research.

  10. Integration of amperometric sensors for microchip capillary electrophoresis application

    NASA Astrophysics Data System (ADS)

    Dicorato, F.; Moore, E.; Glennon, J.

    2011-08-01

    Capillary electrophoresis is a technique for the separation and analysis of chemical compounds. Techniques adopted from the microchip technology knowledge have led to recent developments of electrophoresis system with integration on microchip. Microchip Capillary Electrophoresis (μCE) systems offer a series of advantages as easy integration for Lab-on-a-chip applications, high performance, portability, speed, minimal solvent and sample requirements. A new technological challenge aims at the development of an economic modular microchip capillary electrophoresis systems using separable and independent units concerning the sensor. In this project we worked on the development of an interchangeable amperometric sensor in order to provide a solution to such electrode passivation and facilitating the use of tailored sensors for specific analyte detection besides. Fluidic chips have been machined from cyclic olefin polymer pallets (Zeonor®) using a micro-injection molding machine.

  11. Evaluation of different protein extraction methods for banana (Musa spp.) root proteome analysis by two-dimensional electrophoresis.

    PubMed

    Vaganan, M Mayil; Sarumathi, S; Nandakumar, A; Ravi, I; Mustaffa, M M

    2015-02-01

    Four protocols viz., the trichloroacetic acid-acetone (TCA), phenol-ammonium acetate (PAA), phenol/SDS-ammonium acetate (PSA) and trisbase-acetone (TBA) were evaluated with modifications for protein extraction from banana (Grand Naine) roots, considered as recalcitrant tissues for proteomic analysis. The two-dimensional electrophoresis (2-DE) separated proteins were compared based on protein yield, number of resolved proteins, sum of spot quantity, average spot intensity and proteins resolved in 4-7 pI range. The PAA protocol yielded more proteins (0.89 mg/g of tissues) and protein spots (584) in 2-DE gel than TCA and other protocols. Also, the PAA protocol was superior in terms of sum of total spot quantity and average spot intensity than TCA and other protocols, suggesting phenol as extractant and ammonium acetate as precipitant of proteins were the most suitable for banana rooteomics analysis by 2-DE. In addition, 1:3 ratios of root tissue to extraction buffer and overnight protein precipitation were most efficient to obtain maximum protein yield.

  12. Highly sensitive chiral analysis in on-line combined chiral and achiral media by capillary zone electrophoresis.

    PubMed

    Krásenský, S; Fanali, S; Krivánková, L; Bocek, P

    1995-06-01

    A new approach is described for highly sensitive chiral analyses by capillary zone electrophoresis, based on using an on-line combination of two capillaries filled with either chiral selective or achiral background electrolytes (BGE). Thus, the BGEs are selected in such a way that the first capillary provides optimum chiral selectivity and the second one optimum detection sensitivity. Direct chiral separations of enantiomers of mandelic, m-methoxymandelic, 3-phenyllactic and 3-indolelactic acids served as a model example for testing the approach proposed. The analyses were performed in a BGE containing acetate as a coion and L-OH-proline or aspartame as a chiral selector. For high sensitive analyses, an arrangement containing on-line combined chiral and achiral media were tested in one or two capillaries coupled via a bifurcation block. A detection limit as low as 10(-18) moles was reached in the column-coupling system when the direct chiral separation was performed in the first capillary, filled with 20 mM acetate buffer, pH 4.4, containing 8 mM Cu (II) and 16 mM aspartame (L-aspartyl-L-phenylalanine methylester) and separated enantiomers were detected in the second capillary, filled with 20 mM acetate buffer, pH 3.1. The principle described is of general use in cases where the separation and detection of analytes in question require mutually different BGEs to reach the optimum selectivity and sensitivity, respectively.

  13. Diced electrophoresis gel assay for screening enzymes with specified activities.

    PubMed

    Komatsu, Toru; Hanaoka, Kenjiro; Adibekian, Alexander; Yoshioka, Kentaro; Terai, Takuya; Ueno, Tasuku; Kawaguchi, Mitsuyasu; Cravatt, Benjamin F; Nagano, Tetsuo

    2013-04-24

    We have established the diced electrophoresis gel (DEG) assay as a proteome-wide screening tool to identify enzymes with activities of interest using turnover-based fluorescent substrates. The method utilizes the combination of native polyacrylamide gel electrophoresis (PAGE) with a multiwell-plate-based fluorometric assay to find protein spots with the specified activity. By developing fluorescent substrates that mimic the structure of neutrophil chemoattractants, we could identify enzymes involved in metabolic inactivation of the chemoattractants.

  14. Observations on Membranes of Mycoplasma laidlawii Strain B

    PubMed Central

    Smith, P. F.; Koostra, W. L.; Mayberry, W. R.

    1969-01-01

    The cytoplasmic membrane of Mycoplasma laidlawii strain B is solubilized by anionic and nonionic detergents, succinylation, phospholipase A, alkaline phosphatase, trypsin, and chymotrypsin. Cationic detergents are without effect, as are chelating agents, even in the presence of high concentrations of monovalent cation. The detergent-solubilized membrane exhibits one peak in the analytical ultracentrifuge, but the sedimentation coefficient is dependent upon concentration of detergent. Simple dialysis does not remove all of the sodium dodecylsulfate except from lipid-depleted membrane particles. Membranes bind sodium dodecylsulfate but acetone powders of membranes do not. Sulfated alcohols with chain lengths of C14 and C16 are more tightly bound than dodecylsulfate. A constant amount of di- and trivalent cation is bound by the membrane upon aggregation. Only a portion of this cation is removable with chelating agents. No chelating agent is bound by these aggregates. A portion of the lipid-depleted membrane particles is solubilized by negatively charged lipids and detergents, giving rise to aggregates in the presence of divalent cation. Fractionations of detergent-solubilized membranes by preparative gel electrophoresis and ammonium sulfate were inconclusive. Density gradient centrifugation of succinylated membranes yielded at least five fractions which exhibited homogeneity by ultracentrifugation. Analytical gel electrophoresis of these fractions demonstrated heterogeneity. The composition of these five fractions suggested separation of protein from lipid. PMID:5361209

  15. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  16. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:27620084

  17. Reversible gels for electrophoresis and isolation of DNA.

    PubMed

    Cole, K D

    1999-04-01

    Here, the application of the gel-forming carbohydrate polymer, gellan gum, for the electrophoresis and isolation of DNA is detailed. Gellan gun forms gels in the presence of divalent metal cations, and the gels can be converted back to a solution by the addition of a chelating agent such as EDTA. Also, gellan electrophoresis gels can be formed using diamines. These gels are reversible by increasing the pH, which results in the deprotonation of the diamine. Gellan electrophoresis gels were used for separations at concentrations as low as 0.03%. Native gellan electrophoresis gels have significant electroosmosis and were generally run overnight. A gellan electrophoresis gel (0.1%) showed good resolution of DNA from approximately 50-1 kbp. The addition of linear polymers, such as hydroxethyl cellulose, to the gellan gum before casting greatly reduced the electroosmosis. The additional polymer increased the resolution of low-molecular-weight DNA down to approximately 200 bp and allowed gels to be run in a few hours. DNA isolated from gellan electrophoresis gels could be cut by common restriction enzymes and ligated in the presence of the gellan gum. The presence of gellan gum did not significantly inhibit the transformation of competent E. coli cells by plasmid DNA.

  18. Muscle protein analysis by two-dimensional gel electrophoresis

    SciTech Connect

    Giometti, C.S.

    1982-01-01

    Two-dimensional electrophoresis of muscle proteins has provided valuable new information concerning the heterogeneity of some of the major contractile proteins, alterations in the protein population of developing muscle fibers during various stages of myogenesis, and protein aberrations that correlate with muscle diseases. As with all electrophoretic techniques, careful attention must be paid to the preparation of samples and the selection of reagents to be used for the protein separations. Two-dimensional electrophoresis is the obvious method of choice when analysis of protein mixtures is required. The routine clinical application of two-dimensional electrophoresis to analysis of muscle tissue remains to be demonstrated. However, methods of sample preparation for two-dimensional electrophoresis compatible with existing clinical procedures have been described, and the equipment for multiple analyses is available. As protein abnormalities related to human myopathy are detected through the use of two-dimensional electrophoresis as a research tool, useful clinical markers of specific myopathic processes will be found. The preliminary work on muscle protein analysis by two-dimensional electrophoresis described in this review has begun a new approach to the enigma of human muscle disease.

  19. Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

    PubMed

    Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

    2015-05-01

    In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid.

  20. Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...

  1. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  2. 40 CFR 721.10001 - 2-Ethoxyethanol, 2-ethoxyethanol acetate, 2-methoxyethanol, and 2-methoxyethanol acetate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... new uses subject to reporting. (1) The chemical substances identified as 2-ethoxyethanol (CAS No. 110-80-5), 2-ethoxyethanol acetate (CAS No. 111-15-9), 2-methoxyethanol (CAS No. 109-86-4), and 2-methoxyethanol acetate (CAS No. 110-49-6) are subject to reporting under this section for the significant new...

  3. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    ERIC Educational Resources Information Center

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  4. A novel approach to pseudopodia proteomics: excimer laser etching, two-dimensional difference gel electrophoresis, and confocal imaging

    PubMed Central

    Mimae, Takahiro; Ito, Akihiko; Hagiyama, Man; Nakanishi, Jun; Hosokawa, Yoichiroh; Okada, Morihito; Murakami, Yoshinori; Kondo, Tadashi

    2014-01-01

    Pseudopodia are actin-rich ventral cellular protrusions shown to facilitate the migration and metastasis of tumor cells. Here, we present a novel approach to perform pseudopodia proteomics. Tumor cells growing on porous membranes extend pseudopodia into the membrane pores. In our method, cell bodies are removed by horizontal ablation at the basal cell surface with the excimer laser while pseudopodia are left in the membrane pores. For protein expression profiling, whole cell and pseudopodia proteins are extracted with a lysis buffer, labeled with highly sensitive fluorescent dyes, and separated by two-dimensional gel electrophoresis. Proteins with unique expression patterns in pseudopodia are identified by mass spectrometry. The effects of the identified proteins on pseudopodia formation are evaluated by measuring the pseudopodia length in cancer cells with genetically modified expression of target proteins using confocal imaging. This protocol allows global identification of pseudopodia proteins and evaluation of their functional significance in pseudopodia formation within one month. PMID:25309719

  5. Multicomponent membranes

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    1988-01-01

    A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

  6. Charged membranes.

    PubMed

    Thatcher, Jack D

    2013-04-16

    This Teaching Resource provides three animated lessons that describe the storage and utilization of energy across plasma membranes. The "Na,K ATPase" animation explains how these pumps establish the electrochemical gradient that stores energy across plasma membranes. The "ATP synthesizing complexes" animation shows how these complexes transfer energy from the inner mitochondrial membrane to adenosine triphosphate (ATP). The "action potential" lesson explains how charged membranes are used to propagate signals along the axons of neurons. These animations serve as valuable resources for any collegiate-level course that describes these important factors. Courses that might employ them include introductory biology, biochemistry, biophysics, cell biology, pharmacology, and physiology.

  7. Analysis of the Microbial Community in an Acidic Hollow-Fiber Membrane Biofilm Reactor (Hf-MBfR) Used for the Biological Conversion of Carbon Dioxide to Methane.

    PubMed

    Shin, Hyun Chul; Ju, Dong-Hun; Jeon, Byoung Seung; Choi, Okkyoung; Kim, Hyun Wook; Um, Youngsoon; Lee, Dong-Hoon; Sang, Byoung-In

    2015-01-01

    Hydrogenotrophic methanogens can use gaseous substrates, such as H2 and CO2, in CH4 production. H2 gas is used to reduce CO2. We have successfully operated a hollow-fiber membrane biofilm reactor (Hf-MBfR) for stable and continuous CH4 production from CO2 and H2. CO2 and H2 were diffused into the culture medium through the membrane without bubble formation in the Hf-MBfR, which was operated at pH 4.5-5.5 over 70 days. Focusing on the presence of hydrogenotrophic methanogens, we analyzed the structure of the microbial community in the reactor. Denaturing gradient gel electrophoresis (DGGE) was conducted with bacterial and archaeal 16S rDNA primers. Real-time qPCR was used to track changes in the community composition of methanogens over the course of operation. Finally, the microbial community and its diversity at the time of maximum CH4 production were analyzed by pyrosequencing methods. Genus Methanobacterium, related to hydrogenotrophic methanogens, dominated the microbial community, but acetate consumption by bacteria, such as unclassified Clostridium sp., restricted the development of acetoclastic methanogens in the acidic CH4 production process. The results show that acidic operation of a CH4 production reactor without any pH adjustment inhibited acetogenic growth and enriched the hydrogenotrophic methanogens, decreasing the growth of acetoclastic methanogens. PMID:26694756

  8. Analysis of the Microbial Community in an Acidic Hollow-Fiber Membrane Biofilm Reactor (Hf-MBfR) Used for the Biological Conversion of Carbon Dioxide to Methane

    PubMed Central

    Jeon, Byoung Seung; Choi, Okkyoung; Kim, Hyun Wook; Um, Youngsoon; Lee, Dong-Hoon; Sang, Byoung-In

    2015-01-01

    Hydrogenotrophic methanogens can use gaseous substrates, such as H2 and CO2, in CH4 production. H2 gas is used to reduce CO2. We have successfully operated a hollow-fiber membrane biofilm reactor (Hf-MBfR) for stable and continuous CH4 production from CO2 and H2. CO2 and H2 were diffused into the culture medium through the membrane without bubble formation in the Hf-MBfR, which was operated at pH 4.5–5.5 over 70 days. Focusing on the presence of hydrogenotrophic methanogens, we analyzed the structure of the microbial community in the reactor. Denaturing gradient gel electrophoresis (DGGE) was conducted with bacterial and archaeal 16S rDNA primers. Real-time qPCR was used to track changes in the community composition of methanogens over the course of operation. Finally, the microbial community and its diversity at the time of maximum CH4 production were analyzed by pyrosequencing methods. Genus Methanobacterium, related to hydrogenotrophic methanogens, dominated the microbial community, but acetate consumption by bacteria, such as unclassified Clostridium sp., restricted the development of acetoclastic methanogens in the acidic CH4 production process. The results show that acidic operation of a CH4 production reactor without any pH adjustment inhibited acetogenic growth and enriched the hydrogenotrophic methanogens, decreasing the growth of acetoclastic methanogens. PMID:26694756

  9. Investigations of the inhibitory effects of tocopherol (vitamin E) on free radical deterioration of cellular membranes

    NASA Technical Reports Server (NTRS)

    Richardson, D.

    1975-01-01

    The inhibitory effects are investigated of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate on the free radical deterioration of cellular membranes. The level of toxicity of d,1-alpha-tocopherol and d,1-alpha-tocopheryl acetate in mice is determined.

  10. Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

    PubMed

    Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

    2014-03-01

    This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L.

  11. Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

    PubMed

    Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

    2014-03-01

    This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. PMID:24434701

  12. Dynamic Protonation Equilibrium of Solvated Acetic Acid

    SciTech Connect

    Gu, Wei; Frigato, Tomaso; Straatsma, TP; Helms, Volkhard H.

    2007-04-13

    For the first time, the dynamic protonation equilibrium between an amino acid side chain analogue and bulk water as well as the diffusion properties of the excess proton were successfully reproduced through unbiased computer simulations. During a 50 ns Q-HOP MD simulation, two different regimes of proton transfer were observed. Extended phases of frequent proton swapping between acetic acid and nearby water were separated by phases where the proton freely diffuses in the simulation box until it is captured again by acetic acid. The pKa of acetic acid was calculated around 3.0 based on the relative population of protonated and deprotonated states and the diffusion coefficient of excess proton was computed from the average mean squared displacement in the simulation. Both calculated values agree well with the experimental measurements.

  13. Induction of active immunity with membrane fractions from Haemophilus influenzae type b.

    PubMed Central

    Burans, J P; Lynn, M; Solotorovsky, M

    1983-01-01

    Using Escherichia coli strain E-1 as a model, we developed procedures for the preparation of outer- and inner-membrane-enriched fractions as structural units. These procedures could be used to prepare relatively pure inner and outer membrane fractions as determined by succinate dehydrogenase activity, ketodeoxyoctonate levels, and polyacrylamide gradient gel electrophoresis. The use of these procedures to fractionate membrane components from Haemophilus influenzae type b strains H-2 and H-E led to good separation of outer- and inner-membrane-enriched fractions as determined by succinate dehydrogenase and ketodeoxyoctonate levels but incomplete separation as determined by polyacrylamide gradient gel electrophoresis. Although there were differences between the electrophoresis profiles of outer membrane fractions of strains H-2 and H-E, immunization with outer membrane of either strain led to the induction of a high degree of immunoprotection against challenge with the H-2 strain. Protection could also be elicited with inner membrane preparations, but such protection may be due to contamination with outer membrane. Extracted membrane protein induced levels of protection that were comparable to those induced by whole membrane fractions. Images PMID:6602769

  14. Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.

    PubMed

    Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

    2013-09-01

    In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates. PMID:23907067

  15. Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.

    PubMed

    Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

    2013-09-01

    In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates.

  16. Leuprolide acetate-induced generalized papular eruption.

    PubMed

    Burris, Katy; Ding, Catherine Y; Lim, Geoffrey F S

    2014-06-01

    Leuprolide acetate, a gonadotropin-releasing hormone agonist, is used in the treatment of prostate cancer. We report a unique case of a disseminated papular rash following leuprolide acetate injections in a 65-year-old man that shares clinical and histopathological features of papuloerythroderma of Ofuji. Leuprolide-induced papuloerythroderma, as well as a limited number of other disseminated cutaneous eruptions caused by this drug, is extremely rare, with only one case previously reported. Our case calls attention to this uncommon side effect in a commonly used hormonal therapy.

  17. Characterization of microporous membranes using confocal scanning laser microscopy in fluorescence mode

    NASA Astrophysics Data System (ADS)

    Charcosset, C.; Bernengo, J.-C.

    2000-12-01

    Confocal Scanning Laser Microscopy (CSLM) in fluorescence mode was used to characterize microporous membranes. Two microfiltration membranes were investigated: a mixed ester (cellulose nitrate/cellulose acetate) 1.2 μm-rated membrane and a polycarbonate track-etched membrane with cylindrical pores of 2 μm diameter. Optical sections of the membranes stained with rhodamine and mounted in glycerol were performed at 1 μm intervals, from 0 to 10 μm. CSLM was found useful for microporous membrane characterization, as it gives some insight into bulk membrane morphology.

  18. Monitoring antigenic protein integrity during glycoconjugate vaccine synthesis using capillary electrophoresis-mass spectrometry.

    PubMed

    Tengattini, Sara; Domínguez-Vega, Elena; Temporini, Caterina; Terreni, Marco; Somsen, Govert W

    2016-09-01

    A capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the characterization and integrity assessment of the Mycobacterium tuberculosis (MTB) antigens TB10.4 and Ag85B and their chemically produced glycoconjugates, which are glycovaccine candidates against tuberculosis (TB). In order to prevent protein adsorption to the inner capillary wall and to achieve efficient separation of the antigen proteoforms, a polyionic multilayer coating of polybrene-dextran sulfate-polybrene (PB-DS-PB) was used in combination with 1.5 M acetic acid as background electrolyte (BGE). Coupling of CE to high-resolution time-of-flight MS was achieved by a coaxial interface employing a sheath liquid of isopropanol-water (50:50, v/v) containing 0.1 % formic acid. The MTB antigens were exposed to experimental conditions used for chemical glycosylation (but no activated saccharide was added) in order to investigate their stability during glycovaccine production. CE-MS analysis revealed the presence of several closely related degradation products, including truncated, oxidized and conformational variants, which were assigned by accurate mass. Analysis of synthesized mannose conjugates of TB10.4 and Ag85B allowed the determination of the glycoform composition of the neo-glycoproteins next to the characterization of degradation products which were shown to be partly glycoconjugated. Moreover, the selectivity of CE-MS allowed specific detection of deamidated species (protein mass change of 1.0 Da only), indicating that chemical glycosylation increased susceptibility to deamidation. Overall, the results show that CE-MS represents a useful analytical tool for the detailed characterization and optimization of neo-glycoconjugate products. Graphical Abstract Flowchart illustrating Mycobacterium tuberculosis (MTB) antigen glycosylation, glycoconjugate variant and degradation product separation by capillary electrophoresis (CE) and their characterization by intact mass

  19. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, K.D.; Chu, T.J.; Pitt, W.G.

    1992-05-12

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings

  20. Recent Developments in Instrumentation for Capillary Electrophoresis and Microchip-Capillary Electrophoresis

    PubMed Central

    Felhofer, Jessica L.; Blanes, Lucas; Garcia, Carlos D.

    2010-01-01

    Over the last years there has been an explosion in the number of developments and applications of capillary electrophoresis (CE) and microchip-CE. In part, this growth has been the direct consequence of recent developments in instrumentation associated with CE. This review, which is focused on contributions published in the last five years, is intended to complement the papers presented in this special issue dedicated to Instrumentation and to provide an overview on the general trend and some of the most remarkable developments published in the areas of high voltage power supplies, detectors, auxiliary components, and compact systems. It also includes few examples of alternative uses of and modifications to traditional CE instruments. PMID:20665910

  1. Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms

    SciTech Connect

    Orita, Masato; Iwahana, Hiroyuki; Kanazawa, Hiroshi; Hayashi, Kenshi; Sekiya, Takao )

    1989-04-01

    The authors developed mobility shift analysis of single-stranded DNAs on neutral polyacrylamide gel electrophoresis to detect DNA polymorphisms. This method follows digestion of genomic DNA with restriction endonucleases, denaturation in alkaline solution, and electrophoresis on a neutral polyacrylamide gel. After transfer to a nylon membrane, the mobility shift due to a nucleotide substitution of a single-stranded DNA fragment could be detected by hybridization with a nick-translated DNA fragment or more clearly with RNA copies synthesized on each strand of the DNA fragment as probes. As the mobility shift caused by nucleotide substitutions might be due to a conformational change of single-stranded DNAs, we designate the features of single-stranded DNAs as single-strand conformation polymorphisms (SSCPs). Like restriction fragment length polymorphisms (RFLPs), SSCPs were found to be allelic variants of true Mendelian traits, and therefore they should be useful genetic markers. Moreover, SSCP analysis has the advantage over RFLP analysis that it can detect DNA polymorphisms and point mutations at a variety of positions in DNA fragments. Since DNA polymorphisms have been estimated to occur every few hundred nucleotides in the human genome, SSCPs may provide many genetic markers.

  2. Trypanosomatidae produce acetate via a mitochondrial acetate:succinate CoA transferase.

    PubMed

    Van Hellemond, J J; Opperdoes, F R; Tielens, A G

    1998-03-17

    Hydrogenosome-containing anaerobic protists, such as the trichomonads, produce large amounts of acetate by an acetate:succinate CoA transferase (ASCT)/succinyl CoA synthetase cycle. The notion that mitochondria and hydrogenosomes may have originated from the same alpha-proteobacterial endosymbiont has led us to look for the presence of a similar metabolic pathway in trypanosomatids because these are the earliest-branching mitochondriate eukaryotes and because they also are known to produce acetate. The mechanism of acetate production in these organisms, however, has remained unknown. Four different members of the trypanosomatid family: promastigotes of Leishmania mexicana mexicana, L. infantum and Phytomonas sp., and procyclics of Trypanosoma brucei were analyzed as well as the parasitic helminth Fasciola hepatica. They all use a mitochondrial ASCT for the production of acetate from acetyl CoA. The succinyl CoA that is produced during acetate formation by ASCT is recycled presumably to succinate by a mitochondrial succinyl CoA synthetase, concomitantly producing ATP from ADP. The ASCT of L. mexicana mexicana promastigotes was further characterized after partial purification of the enzyme. It has a high affinity for acetyl CoA (Km 0.26 mM) and a low affinity for succinate (Km 6.9 mM), which shows that significant acetate production can occur only when high mitochondrial succinate concentrations prevail. This study identifies a metabolic pathway common to mitochondria and hydrogenosomes, which strongly supports a common origin for these two organelles.

  3. Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method.

    PubMed

    Fernández-Pérez, Rocío; Torres, Carmen; Sanz, Susana; Ruiz-Larrea, Fernanda

    2010-12-01

    Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) - PCR analysis. The comparative study of both methods showed that restriction fragment PFGE of SpeI digests of total DNA was a suitable method for strain typing and for determining which strains were present in vinegar fermentations. Results showed that strains of the species Gluconacetobacter europaeus were the most frequent leader strains of fermentations by the submerged method in the studied vinegars, and among them strain R1 was the predominant one. Results showed as well that mixed populations (at least two different strains) occurred in vinegars from cider and wine, whereas unique strains were found in spirit vinegars, which offered the most stressing conditions for bacterial growth.

  4. Recovery of volatile fatty acids via membrane contactor using flat membranes: experimental and theoretical analysis.

    PubMed

    Tugtas, Adile Evren

    2014-07-01

    Volatile fatty acid (VFA) separation from synthetic VFA solutions and leachate was investigated via the use of a membrane contactor. NaOH was used as a stripping solution to provide constant concentration gradient of VFAs in both sides of a membrane. Mass flux (12.23 g/m(2)h) and selectivity (1.599) observed for acetic acid were significantly higher than those reported in the literature and were observed at feed pH of 3.0, flow rate of 31.5 ± 0.9 mL/min, and stripping solution concentration of 1.0 N. This study revealed that the flow rate, stripping solution strength, and feed pH affect the mass transfer of VFAs through the PTFE membrane. Acetic and propionic acid separation performances observed in the present study provided a cost effective and environmental alternative due to elimination of the use of extractants.

  5. Antimicrobial electrospun nanofibers of cellulose acetate and polyester urethane composite for wound dressing.

    PubMed

    Liu, Xin; Lin, Tong; Gao, Yuan; Xu, Zhiguang; Huang, Chen; Yao, Gang; Jiang, Linlin; Tang, Yanwei; Wang, Xungai

    2012-08-01

    In this study, a series of nanofibrous membranes were prepared from cellulose acetate (CA) and polyester urethane (PEU) using coelectrospinning or blend-electrospinning. The drug release, in vitro antimicrobial activity and in vivo wound healing performance of the nanofiber membranes were evaluated for use as wound dressings. To prevent common clinical infections, an antimicrobial agent, polyhexamethylene biguanide (PHMB) was incorporated into the electrospun fibers. The presence of CA in the nanofiber membrane improved its hydrophilicity and permeability to air and moisture. CA fibers became slightly swollen upon contacting with liquid phase. CA not only increased the liquid uptake but also created a moist environment for the wound, which accelerated wound recovery. PHMB release dynamics of the membranes was controlled by the structure and component ratios of the membranes. The lower ratio of CA: PEU helped to preserve the physical and thermal properties of the membranes, and also reduced the burst release effectively and slowed down diffusion of PHMB during in vitro tests. The controlled-diffusion membranes exerted long-term antimicrobial effect for wound healing.

  6. [Valuation of absorption of organic compounds in human body using liposome capillary electrophoresis].

    PubMed

    Zou, Xiaobing; Jiang, Honggui; Dong, Zhiqiang; Xia, Zhining; Jiang, Xuemei

    2008-11-01

    Liposome capillary electrophoresis (LCE) was used as a model for the in vitro evaluation of the degree of membrane penetration of organic compounds. The hydrophobic parameters of 9 compounds were determined by LCE. In comparison of the correlation coefficient of log P(lw) (the logarithm of the partition coefficient of liposome/water system, calculated from retention factor) vs. log P(m) (the logarithm of osmotic coefficient) with that of log P(ow) (the logarithm of the partition coefficient of octanol/water system) vs. log P(m), the former was 0.94, much greater than the latter 0.78. It means that as the biomembrane model, liposome is more similar than the octanol/water system. The LCE method has the potential to be an in vitro screening model.

  7. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-02-17

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

  8. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

  9. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    NASA Technical Reports Server (NTRS)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  10. Advanced Colloids Experiment (ACE-T1)

    NASA Technical Reports Server (NTRS)

    Meyer, William V.; Sicker, Ron; Brown, Dan; Eustace, John

    2015-01-01

    Increment 45 - 46 Science Symposium presentation of Advanced Colloids Experiment (ACE-T1) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  11. Corrosion of stainless steel during acetate production

    SciTech Connect

    Qi, J.S.; Lester, G.C.

    1996-07-01

    Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

  12. Synthesis of Cellulose Acetate from Cotton Byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton burr and cottonseed hull are relatively inexpensive cotton byproducts. In an effort to derive greater value out of these natural renewable materials, we have succeeded in converting part of them into cellulose acetate without prior chemical breakdown or physical separation of cellulose, ligni...

  13. Optimization of in-line fritless solid-phase extraction for capillary electrophoresis-mass spectrometry.

    PubMed

    Tak, Yvonne H; Toraño, Javier Sastre; Somsen, Govert W; de Jong, Gerhardus J

    2012-12-01

    In this study, in-line frit-free solid-phase extraction (SPE) has been studied for the preconcentration of analytes prior to analysis by capillary electrophoresis-mass spectrometry (CE-MS). The mixed-mode sorbent Oasis HLB was selected for the trapping of compounds of different polarity. Using 2-ethylidene-1,5-dimethyl-3,3-diphenylpirrolidine (EDDP), dihydrocodeine and codeine as test compounds, SPE parameters such as the pH of the sample and composition of the washing and elution solvent were optimized. Trapping of the analytes was optimal at pH 8.0 or higher. For efficient elution of the SPE micro column, 85% of methanol in water with 2% (v/v) acetic acid was used, which also prevented current break down in subsequent CE analysis. CE resolution of the test compounds was highest for background electrolytes (BGEs) with a pH above 8. For optimal analysis, samples were 1:1 diluted with carbonate buffer (1M, pH 8.0) prior to analysis, BGE was 60mM ammonium acetate buffer (pH 10.0), and the injected sample volume was 60 μl (i.e., 30 capillary volumes). Good recoveries were found: 101% for EDDP, 88% for codeine and 90% for dihydrocodeine. Intraday RSDs for migration time and peak areas were below 0.56% and 15%, respectively. Peak widths at half height obtained with SPE-CE-MS were 12s for EDDP, 3.7s for dihydrocodeine and 7.4s for codeine, and were comparable to those for CE-MS. LODs were 0.22 pg/ml for EDDP, 2.1 pg/ml for dihydrocodeine and 24 pg/ml for codeine. It is concluded that the applied fritless in-line preconcentration construct proved to be highly useful for improving the sensitivity of CE while maintaining separation.

  14. Metalless electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips.

    PubMed

    Duarte Junior, Gerson F; Fracassi da Silva, José Alberto; Mendonça Francisco, Kelliton José; do Lago, Claudimir Lucio; Carrilho, Emanuel; Coltro, Wendell K T

    2015-08-01

    This paper describes the use of ionic solutions as sensing electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips. Initially, two channels were engraved in a PMMA holder by using a CO2 laser system and sealed with a thin adhesive membrane. PDMS electrophoresis chips were fabricated by soft lithography and reversibly sealed against the polymer membrane. Different ionic solutions were investigated as metalless electrodes. The electrode channels were filled with KCl solutions prepared in conductivity values from approximately 10 to 40 S/m. The best analytical response was achieved using the KCl solution with 21.9 S/m conductivity (2 mol/L). Besides KCl, we also tested NaCl and LiCl solutions for actuating as detection electrodes. Taking into account the same electrolyte concentration (2 mol/L), the best response was recorded with KCl solution due to its higher ionic conductivity. The optimum operating frequency (400 kHz) and the best sensing electrode (2 mol/L KCl) were used to monitor electrophoretic separations of a mixture containing K(+) , Na(+) , and Li(+) . The use of liquid solutions as sensing electrodes for capacitively coupled contactless conductivity detection measurements has revealed great performance to monitor separations on chip-based devices, avoiding complicated fabrication schemes to include metal deposition and encapsulation of electrodes. The LOD values were estimated to be 28, 40, and 58 μmol/L for K(+) , Na(+) , and Li(+) , respectively, what is comparable to that of conventional metal electrodes. When compared to the use metal electrodes, the proposed approach offers advantages regarding the easiness of fabrication, simplicity, and lower cost per device.

  15. Addition of lipid to the photosynthetic membrane: effects on membrane structure and energy transfer

    PubMed Central

    1981-01-01

    We have carried out a series of experiments in which the lipid composition of the photosynthetic membrane has been altered by the addition of lipid from a defined source under experimental conditions. Liposomes prepared by sonication are mixed with purified photosynthetic membranes obtained from spinach chloroplasts and are taken through cycles of freezing and thawing. Several lines of evidence, including gel electrophoresis and freeze-fracture electron microscopy, indicate that an actual addition of lipid has taken place. Structural analysis by freeze-fracture shows that intramembrane particles are widely separated after the addition of large amounts of lipid, with one exception: large hexagonal lattices of particles appear in some regions of the membrane. These lattices are identical in appearance with lattices formed from a single purified component of the membrane known as chlorophyll-protein complex II. The suggestion that the presence of such lattices in lipid-enriched membranes reflects a profound rearrangement of photosynthetic structures has been confirmed by analysis of the fluorescence emission spectra of natural and lipid- enriched membranes. Specifically, lipid addition in each of the cases we have studied results in the apparent detachment of chlorophyll- protein complex II from photosynthetic reaction centers. It is concluded that specific arrangements of components in the photosynthetic membrane, necessary for the normal functioning of the membrane in the light reaction of photosynthesis, can be regulated to a large extent by the lipid content of the membrane. PMID:7298712

  16. Crystalline Membranes

    NASA Technical Reports Server (NTRS)

    Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)

    2008-01-01

    In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

  17. An Alternating Current Electroosmotic Pump Based on Conical Nanopore Membranes.

    PubMed

    Wu, Xiaojian; Ramiah Rajasekaran, Pradeep; Martin, Charles R

    2016-04-26

    Electroosmotic flow (EOF) is used to pump solutions through microfluidic devices and capillary electrophoresis columns. We describe here an EOF pump based on membrane EOF rectification, an electrokinetic phenomenon we recently described. EOF rectification requires membranes with asymmetrically shaped pores, and conical pores in a polymeric membrane were used here. We show here that solution flow through the membrane can be achieved by applying a symmetrical sinusoidal voltage waveform across the membrane. This is possible because the alternating current (AC) carried by ions through the pore is rectified, and we previously showed that rectified currents yield EOF rectification. We have investigated the effect of both the magnitude and frequency of the voltage waveform on flow rate through the membrane, and we have measured the maximum operating pressure. Finally, we show that operating in AC mode offers potential advantages relative to conventional DC-mode EOF pumps. PMID:27046145

  18. Purification and properties of methyl coenzyme M methylreductase from acetate-grown Methanosarcina thermophila.

    PubMed Central

    Jablonski, P E; Ferry, J G

    1991-01-01

    Methyl coenzyme M methylreductase from acetate-grown Methanosarcina thermophila TM-1 was purified 16-fold from a cell extract to apparent homogeneity as determined by native polyacrylamide gel electrophoresis. Ninety-four percent of the methylreductase activity was recovered in the soluble fraction of cell extracts. The estimated native molecular weight of the enzyme was between 132,000 (standard deviation [SD], 1,200) and 141,000 (SD, 1,200). Denaturing polyacrylamide gel electrophoresis revealed three protein bands corresponding to molecular weights of 69,000 (SD, 1,200), 42,000 (SD, 1,200), and 33,000 (SD, 1,200) and indicated a subunit configuration of alpha 1 beta 1 gamma 1. As isolated, the enzyme was inactive but could be reductively reactivated with titanium (III) citrate or reduced ferredoxin. ATP stimulated enzyme reactivation and was postulated to be involved in a conformational change of the inactive enzyme from an unready state to a ready state that could be reductively reactivated. The temperature and pH optima for enzyme activity were 60 degrees C and between 6.5 and 7.0, respectively. The active enzyme contained 1 mol of coenzyme F430 per mol of enzyme (Mr, 144,000). The Kms for 2-(methylthio)ethane-sulfonate and 7-mercaptoheptanoylthreonine phosphate were 3.3 mM and 59 microM, respectively. Images PMID:2013570

  19. Purification and properties of methyl coenzyme M methylreductase from acetate-grown Methanosarcina thermophila.

    PubMed

    Jablonski, P E; Ferry, J G

    1991-04-01

    Methyl coenzyme M methylreductase from acetate-grown Methanosarcina thermophila TM-1 was purified 16-fold from a cell extract to apparent homogeneity as determined by native polyacrylamide gel electrophoresis. Ninety-four percent of the methylreductase activity was recovered in the soluble fraction of cell extracts. The estimated native molecular weight of the enzyme was between 132,000 (standard deviation [SD], 1,200) and 141,000 (SD, 1,200). Denaturing polyacrylamide gel electrophoresis revealed three protein bands corresponding to molecular weights of 69,000 (SD, 1,200), 42,000 (SD, 1,200), and 33,000 (SD, 1,200) and indicated a subunit configuration of alpha 1 beta 1 gamma 1. As isolated, the enzyme was inactive but could be reductively reactivated with titanium (III) citrate or reduced ferredoxin. ATP stimulated enzyme reactivation and was postulated to be involved in a conformational change of the inactive enzyme from an unready state to a ready state that could be reductively reactivated. The temperature and pH optima for enzyme activity were 60 degrees C and between 6.5 and 7.0, respectively. The active enzyme contained 1 mol of coenzyme F430 per mol of enzyme (Mr, 144,000). The Kms for 2-(methylthio)ethane-sulfonate and 7-mercaptoheptanoylthreonine phosphate were 3.3 mM and 59 microM, respectively. PMID:2013570

  20. Absorbance detector for capillary electrophoresis based on light-emitting diodes and photodiodes for the deep-ultraviolet range.

    PubMed

    Bui, Duy Anh; Hauser, Peter C

    2015-11-20

    A new absorbance detector for capillary electrophoresis featuring relatively high intensity light-emitting diodes as radiation sources and photodiodes for the deep-UV range was developed. The direct relationship of absorbance values and concentrations was obtained by emulating Lambert-Beer's law with the application of a beam splitter to obtain a reference signal and a log-ratio amplifier circuitry. The performance of the cell was investigated at 255 nm with the detection of sulfanilic, 4-nitrobenzoic, 4-hydroxybenzoic and 4-aminobenzoic acid and the indirect detection of acetate, propionate, butyrate and caproate using benzoate as the displacement dye molecule. Vanillic acid, L-tyrosine and DL-tryptophan as well as the sulfonamides sulfamerazine, sulfathiazole and sulfamethazine were determined at 280 nm. Good linearities over 3 orders of magnitude were obtained. The noise level recorded was as low as 50 μAU and the drift typically <200 μAU/5 min.

  1. Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.

    ERIC Educational Resources Information Center

    Hocking, M. B.

    1980-01-01

    Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)

  2. The microwave spectrum of n-hexyl acetate and structural aspects of n-alkyl acetates

    NASA Astrophysics Data System (ADS)

    Attig, T.; Kannengießer, R.; Kleiner, I.; Stahl, W.

    2014-04-01

    The microwave spectrum of n-hexyl acetate was recorded in the range of 10-13.5 GHz using the Aachen MB-FTMW spectrometer. The rotational constants of the most abundant conformer were determined to be A = 3.3591100(32) GHz, B = 0.39596553(53) GHz, and C = 0.36999804(31) GHz. Quantum chemical calculations for specific conformers were carried out at the MP2/6-311++G(d,p) level. The programs XIAM and BELGI were used to analyze the internal rotation of the acetyl methyl group. The observed conformer of n-hexyl acetate was compared to the lowest energy conformers of n-butyl acetate and n-pentyl acetate.

  3. Synchrotron radiation for direct analysis of metalloproteins on electrophoresis gels.

    PubMed

    Ortega, Richard

    2009-03-01

    Metalloproteomics requires analytical techniques able to assess and quantify the inorganic species in metalloproteins. The most widely used methods are hyphenated techniques, based on the coupling of a high resolution chromatographic method with a high sensitivity method for metal analysis in solution. An alternative approach is the use of methods for solid sample analysis, combining metalloprotein separation by gel electrophoresis and direct analysis of the gels. Direct methods are based on beam analysis, such as lasers, ion beams or synchrotron radiation beams. The aim of this review article is to present the main features of synchrotron radiation based methods and their applications for metalloprotein analysis directly on electrophoresis gels. Synchrotron radiation X-ray fluorescence has been successfully employed for sensitive metal identification, and X-ray absorption spectroscopy for metal local structure speciation in proteins. Synchrotron based methods will be compared to ion beam and mass spectrometry for direct analysis of metalloproteins in electrophoresis gels.

  4. Enantiomeric resolution of multiple chiral centres racemates by capillary electrophoresis.

    PubMed

    Ali, Imran; Suhail, Mohd; Al-Othman, Zeid A; Alwarthan, Abdulrahman; Aboul-Enein, Hassan Y

    2016-05-01

    Enantiomeric resolution of multichiral centre racemates is an important area as some multichiral centre racemates are of great medicinal importance. However, enantioseparation of such types of racemates is a challenging task. Amongst many analytical techniques, capillary electrophoresis is a powerful technique and may be used to resolve such racemates. Only few papers are available describing enantiomeric resolution of such racemates. Therefore, efforts have been made to describe the enantiomeric resolution of multichiral centre racemates by capillary electrophoresis. This article discusses the importance of multichiral racemates, the need for capillary electrophoresis in enantiomeric resolution and chiral resolution of multichiral centre racemates using various chiral selectors. Further, attempts have been made to discuss the future challenges and prospects of enantiomeric resolution of multichiral racemates. The various chiral selectors used for the purpose are chiral crown ether, cyclodextrins, polysaccharides, macrocyclic glycopeptide antibiotics and ligand exchange.

  5. Analysis of Common Household Cleaner-Disinfectants by Capillary Electrophoresis

    NASA Astrophysics Data System (ADS)

    Gardner, William P.; Girard, James E.

    2000-10-01

    The use of capillary electrophoresis (CE) as an analytical technique in research, industrial, and commercial laboratories is growing rapidly. It is therefore very important to expose undergraduate instrumental analysis students to capillary electrophoresis. In this report we describe the CE analysis for benzalkonium compounds in common household cleaners and disinfectants. The surfactant nature of the benzalkonium compounds is the key consideration in performing the analysis, and modifications to the CE running buffer must be performed in order to successfully analyze the products. This experiment also illustrates the importance of (i) using peak areas corrected for variations in migration time to improve accuracy and (ii) using internal standards to improve the precision of capillary electrophoresis results.

  6. THERMAL DETECTION OF DNA AND PROTEINS DURING GEL ELECTROPHORESIS

    SciTech Connect

    R. JOHNSTON

    2000-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to try to detect unstained, untagged, unlabeled DNA bands in real-time during gel electrophoresis using simple thermal measurements. The technical and ES&H advantages to this approach could potentially be quite significant, especially given the extreme importance of gel electrophoresis to a wide variety of practical and research fields. The project was unable to demonstrate sufficient thermal sensitivity to detect DNA bands. It is clear that we still do not understand the gel electrophoresis phenomenon very well. The temperature control techniques developed during the course of this project have other useful applications.

  7. Nonlinear electrophoresis in the presence of dielectric decrement

    NASA Astrophysics Data System (ADS)

    Figliuzzi, B.; Chan, W. H. R.; Buie, C. R.; Moran, J. L.

    2016-08-01

    The nonlinear phenomena that occur in the electric double layer (EDL) that forms at charged surfaces strongly influence electrokinetic effects, including electro-osmosis and electrophoresis. In particular, saturation effects due to either dielectric decrement or ion crowding effects are of paramount importance. Dielectric decrement significantly influences the ionic concentration in the EDL at high ζ potential, leading to the formation of a condensed layer near the particle's surface. In this article, we present a model incorporating both steric effects due to the finite size of ions and dielectric decrement to describe the physics in the electric double layer. The model remains valid in both weakly and strongly nonlinear regimes, as long as the electric double layer remains in quasiequilibrium. We apply this model to the study of two archetypal problems in electrokinetics, namely the electrophoresis of particles with fixed surface charges and the electrophoresis of ideally polarizable particles.

  8. Analysis of protein therapeutics by capillary electrophoresis: applications and challenges.

    PubMed

    Ma, S

    2005-01-01

    Capillary electrophoresis (CE) has been increasingly used for the analysis of recombinant protein therapeutics in the biotechnology industry over the past several years. In this paper, an overview of the major applications implemented at Genentech Inc. is presented. The applications highlighted in this article are divided into the following three general areas: (i) CE as a replacement for slab gel electrophoresis, particularly capillary electrophoresis-sodium dodecylsulphate and capillary isoelectric focusing; (ii) CE to monitor protein charge heterogeneity as an orthogonal technique to the traditional on-exchange chromatographic methods; and (iii) CE for carbohydrate analysis, including both oligosaccharide and monosaccharide analysis. Overall, the advantages of these CE-based methodologies include automation, ease of quantification, rapid analysis time, enhanced resolution, and robustness when compared to the traditional methods. There are, however, still some challenges in applying CE for protein analysis, particularly in the area of characterization due to the miniaturization nature of CE.

  9. Nonlinear electrophoresis in the presence of dielectric decrement.

    PubMed

    Figliuzzi, B; Chan, W H R; Buie, C R; Moran, J L

    2016-08-01

    The nonlinear phenomena that occur in the electric double layer (EDL) that forms at charged surfaces strongly influence electrokinetic effects, including electro-osmosis and electrophoresis. In particular, saturation effects due to either dielectric decrement or ion crowding effects are of paramount importance. Dielectric decrement significantly influences the ionic concentration in the EDL at high ζ potential, leading to the formation of a condensed layer near the particle's surface. In this article, we present a model incorporating both steric effects due to the finite size of ions and dielectric decrement to describe the physics in the electric double layer. The model remains valid in both weakly and strongly nonlinear regimes, as long as the electric double layer remains in quasiequilibrium. We apply this model to the study of two archetypal problems in electrokinetics, namely the electrophoresis of particles with fixed surface charges and the electrophoresis of ideally polarizable particles. PMID:27627400

  10. Micro free-flow electrophoresis: theory and applications

    PubMed Central

    Turgeon, Ryan T.

    2009-01-01

    Free-flow electrophoresis (FFE) is a technique that performs an electrophoretic separation on a continuous stream of analyte as it flows through a planar flow channel. The electric field is applied perpendicularly to the flow to deflect analytes laterally according to their mobility as they flow through the separation channel. Miniaturization of FFE (μFFE) over the past 15 years has allowed analytical and preparative separation of small volume samples. Advances in chip design have improved separations by reducing interference from bubbles generated by electrolysis. Mechanisms of band broadening have been examined theoretically and experimentally to improve resolution in μFFE. Separations using various modes such as zone electrophoresis, isoelectric focusing, isotachophoresis, and field-step electrophoresis have been demonstrated. PMID:19290514

  11. Capillary array electrophoresis using laser-excited confocal fluorescence detection

    SciTech Connect

    Huang, X.C.; Quesada, M.A.; Mathies, R.A.

    1992-04-15

    Capillary electrophoresis (CE) has found widespread application in analytical and biomedical research, and the scope and sophistication of CE is still rapidly advancing. Gel-filled capillaries have been employed for the rapid separation and analysis of synthetic polynucleotides, DNA sequencing fragments, and DNA restriction fragments. Open-tube capillary electrophoresis has attained subattomole detection levels in amino acid separations 14 and proven its utility for the separation of proteins, viruses, and bacteria. Separation of the optical isomers of dansyl amino acids has also been successfully demonstrated. Micellar electrokinetic capillary chromatography, isoelectric focusing, and on-column derivatization can all be performed on CE columns, demonstrating the utility of capillary electrophoresis as an analytical and micropreparative tool. 29 refs., 6 figs., 1 tab.

  12. Polyethylene-supported polyvinylidene fluoride-cellulose acetate butyrate blended polymer electrolyte for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Liu, Jiansheng; Li, Weishan; Zuo, Xiaoxi; Liu, Shengqi; Li, Zhao

    2013-03-01

    The polyethylene (PE)-supported polymer membranes based on the blended polyvinylidene fluoride (PVDF) and cellulose acetate butyrate (CAB) are prepared for gel polymer electrolyte (GPE) of lithium ion battery. The performances of the prepared membranes and the resulting GPEs are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, linear potential sweep, and charge-discharge test. The effect of the ratio of PVDF to CAB on the performance of the prepared membranes is considered. It is found that the GPE based on the blended polymer with PVDF:CAB = 2:1 (in weight) has the largest ionic conductivity (2.48 × 10-3 S cm-1) and shows good compatibility with anode and cathode of lithium ion battery. The LiCoO2/graphite battery using this GPE exhibits superior cyclic stability at room temperature, storage performance at elevated temperature, and rate performance.

  13. Determination of inorganic anions in ethyl acetate by ion chromatography with an electromembrane extraction method.

    PubMed

    Hu, Zhenzhen; Chen, Huadong; Yao, Chaoying; Zhu, Yan

    2011-09-01

    In this work, the determination of inorganic anions in slightly water-soluble organic solvents (ethyl acetate) was realized by ion chromatography (IC) with a novel-efficient electromembrane extraction method. From an 8 mL ethyl acetate sample, three inorganic anions migrated through the pores of a polypropylene hollow fiber membrane, and into deionized water inside the lumen of the hollow fiber by the application of 600 V. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of inorganic anions from the donor compartment to the acceptor solution. After the electromembrane extraction, the acceptor solution was analyzed by IC with a sodium carbonate-sodium bicarbonate eluent. The applied voltage, stirring speed, and extraction time for controlling the extraction efficiency were optimized. Within 10 min of operation at 600 V, chloride, bromide, and sulfate were extracted with recoveries in the range 76-110%, which corresponded to a linear range of 0.01-1 mg/L. The procedure was applied to the analysis of inorganic anions in a real ethyl acetate sample and expands onto other slightly water-soluble organic solvents. PMID:21859536

  14. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  15. Membrane Nanotubes

    NASA Astrophysics Data System (ADS)

    Derényi, I.; Koster, G.; van Duijn, M. M.; Czövek, A.; Dogterom, M.; Prost, J.

    There is a growing pool of evidence showing the biological importance of membrane nanotubes (with diameter of a few tens of nanometers and length upto tens of microns) in various intra- and intercellular transport processes. These ubiquitous structures are often formed from flat membranes by highly localized forces generated by either the pulling of motor proteins or the pushing of polymerizing cytoskeletal filaments. In this chapter we give an overview of the theory of membrane nanotubes, their biological relevance, and the most recent experiments designed for the study of their formation and dynamics. We also discuss the effect of membrane proteins or lipid composition on the shape of the tubes, and the effect of antagonistic motor proteins on tube formation.

  16. Fragrance material review on 1,1-dimethyl-2-phenylethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 1,1-dimethyl-2-phenylethyl acetate when used as a fragrance ingredient is presented. 1,1-Dimethyl-2-phenylethyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an Aryl Alkyl Alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to 1,1-dimethyl-2-phenylethyl acetate and is not intended as a stand-alone document. Available data were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; mucous membrane (eye) irritation; skin sensitization; elicitation; and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  17. Fragrance material review on 1,3-dimethyl-3-phenylbutyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 1,3-dimethyl-3-phenylbutyl acetate when used as a fragrance ingredient is presented. 1,3-Dimethyl-3-phenylbutyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1 to 4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1,3-dimethyl-3-phenylbutyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, and photoallergy data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  18. Fragrance material review on 3-phenyl-3-buten-1-yl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 3-phenyl-3-buten-1-yl acetate when used as a fragrance ingredient is presented. 3-Phenyl-3-buten-1-yl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenyl-3-buten-1-yl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  19. Outer membrane protein profiles of Haemophilus pleuropneumoniae.

    PubMed Central

    Rapp, V J; Munson, R S; Ross, R F

    1986-01-01

    Outer membrane protein profiles of Haemophilus pleuropneumoniae were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cells were disrupted by sonication, and outer membrane-enriched fractions were prepared by differential centrifugation and selective solubilization of the inner membrane with sodium N-lauroyl sarcosinate. Colony type, growth medium, time of harvest, and in vitro or in vivo passage had no appreciable effect on the protein profiles of the strains examined. Seven patterns were distinguished among the reference strains of the nine capsular serotypes. These patterns were based on the mobility of the major outer membrane proteins migrating in the 39,000- to 44,000-molecular-weight region of the gel, a 16K to 16.5K protein, and a heat-modifiable 29K protein. Strains of serotypes 1 and 9 had identical outer membrane protein profiles, as did strains of serotypes 2 and 6. The reference strains of the remaining five serotypes each had a distinct pattern. The outer membrane protein profiles of 95 field isolates belonging to serotypes 1, 5, 7, and 9 from swine in the midwestern United States were determined and compared with the reference patterns. The results indicate that the population of H. pleuropneumoniae is clonal, with three predominant clones distinguished by both serotype and outer membrane protein profile responsible for the majority of H. pleuropneumoniae disease occurring in swine in the United States. Images PMID:3699889

  20. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, Karin D.; Chu, Tun-Jen; Pitt, William G.

    1992-01-01

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to said target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membrances may be reprobed numerous times.