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Journal articles on the topic 'Characterization of the columns'

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Author: Grafiati

Published: 10 March 2023

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1

Kato, Akira, Korefumi Nakamura, Hisayuki Kudo, Yen Ha Tran, Yoko Yamamoto, Hiroyuki Doi, and Shigehisa Hirose. "Characterization of the Column and Autocellular Junctions That Define the Vasculature of Gill Lamellae." Journal of Histochemistry & Cytochemistry 55, no. 9 (May 3, 2007): 941–53. http://dx.doi.org/10.1369/jhc.6a7154.2007.

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Novel adhesion junctions have been characterized that are formed at the interface between pillar cells and collagen columns, both of which are essential constituents of the gill lamellae in fish. We termed these junctions the “column junction” and “autocellular junction” and determined their molecular compositions by immunofluorescence microscopy using pufferfish. We visualized collagen columns by concanavalin A staining and found that the components of integrin-mediated cell-matrix adhesion, such as talin, vinculin, paxillin, and fibronectin, were concentrated on plasma membranes surrounding collagen columns (column membranes). This connection is analogous to the focal adhesion of cultured mammalian cells, dense plaque of smooth muscle cells, and myotendinous junction of skeletal muscle cells. We named this connection the “column junction.” In the cytoplasm near the column, actin fibers, actinin, and a phosphorylated myosin light chain of 20 kDa are densely located, suggesting the contractile nature of pillar cells. The membrane infoldings surrounding the collagen columns were found to be connected by the autocellular junction, whose components are highly tyrosine-phosphorylated and contain the tight junction protein ZO-1. This study represents the first molecular characterization and fluorescence visualization of the column and autocellular junctions involved in both maintaining structural integrity and the hemodynamics of the branchial lamellae.

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2

Roehrer, Simon, and Mirjana Minceva. "Evaluation of Inter-Apparatus Separation Method Transferability in Countercurrent Chromatography and Centrifugal Partition Chromatography." Separations 6, no. 3 (July 24, 2019): 36. http://dx.doi.org/10.3390/separations6030036.

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In the countercurrent chromatography and centrifugal partition chromatography, separation method transfer and scale-up is often described as an easy and straightforward procedure. Separation methods are usually developed on lab scale columns and subsequently transferred using linear scale-up factors to semi-preparative or preparative columns of the same column design. However, the separation methods described in the literature have been developed on various columns of different design and size. This is accompanied by differences in the separation behavior of the columns and therefore makes separation method transfer difficult. In the current study, the separation performances of different columns were evaluated and compared. Linear correlations of stationary phase retention and column efficiency as a function of flow rate were found to be applicable for the calculation of separation resolution in the typical operating range of each column. In this context, a two-point short-cut approach for a fast column characterization is recommended. This allows a quick prediction of the separation method transferability between columns, which saves experimental time and effort. In the current study, the transferability between five different columns from lab scale countercurrent chromatography (CCC) (18 mL) to semi-preparative centrifugal partition chromatography (CPCs) (250 mL) with different cell numbers and design is investigated.

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3

Oliveira, V., and R. Vilar. "Characterization of columns grown during KrF laser micromachining of Al2O3–TiC ceramics." Journal of Materials Research 18, no. 5 (May 2003): 1123–30. http://dx.doi.org/10.1557/jmr.2003.0154.

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This paper aims to contribute to the understanding of column formation mechanisms in Al2O3–TiC ceramics micromachined using excimer lasers. Chemical and structural characterization of columns grown in Al2O3–TiC composite processed with 200 KrF laser pulses at 10 J/cm2 was carried out by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction analysis. Fully developed columns consist of a core of unprocessed material surrounded by an outer layer of Al2TiO5, formed in oxidizing conditions, and an inner layer, formed in reducing conditions, composed of TiC and Al3Ti or an AlTi solid solution. Possible mechanisms of column formation are discussed.

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4

Garbassi, F. "Columns: Polymer Analysis and Characterization." Polymer News 30, no. 9 (September 2005): 285–86. http://dx.doi.org/10.1080/00323910500250733.

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5

Rue, Cary A., and Patrick Ryan. "Characterization of pseudorabies virus glycoprotein C attachment to heparan sulfate proteoglycans." Journal of General Virology 83, no. 2 (February 1, 2002): 301–9. http://dx.doi.org/10.1099/0022-1317-83-2-301.

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Pseudorabies virus first attaches to cells through an interaction between the envelope glycoprotein C (gC) and the cell surface heparan sulfate (HS) that is linked to proteoglycans (HSPGs). The HS-binding domain of gC is composed of three discrete heparin-binding domains (HBDs), designated HBD1, -2 and -3 for their proximity to the amino terminus of gC. Each HBD can independently mediate virus attachment to HS, yet each also exhibits a distinct binding preference for differentially sulfated derivatives of heparin. To demonstrate this, affinity columns composed of wild-type gC or mutant gC retaining a single HBD to capture several HSPGs from cultured pig and bovine kidney cells were used. The wild-type gC column bound all of the HSPGs well and, overall, bound more than 90% of the total sample applied to the column. Columns composed of either HBD2 or -3 bound intermediate amounts (40%) of the total sample applied, while the HBD1 column bound low amounts of HSPGs. HBD2 and -3 columns did not uniformly bind all of the HSPGs from bovine kidney cells, but the same HSPGs were bound with equal efficiency on each column. Thus, despite their different preferences for sulfation patterns on HS side-chains, HBD2 and -3 appear to bind the same proteoglycan cores. These results established a hierarchy of HBD2=HBD3>HBD1 in importance for HSPG binding. These in vitro-binding results correlated with the attachment phenotype of virus strains expressing gC with a single HBD in their envelopes.

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6

Stultz, Conner, and Frank L. Dorman. "Characterization of 9 Gas Chromatography Columns by Linear and Lee Retention Indices for Polychlorinated Biphenyls and Polychlorinated Naphthalenes." Separations 7, no. 3 (July 8, 2020): 38. http://dx.doi.org/10.3390/separations7030038.

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Polychlorinated biphenyls (PCBs) and naphthalenes (PCNs) are ubiquitous environmental contaminants with varying degrees of toxicity. There are hundreds of possible congeners with similar chemical characteristics, which make these compounds difficult to isolate in environmental samples. Historically, PCBs and PCNs were identified by using an Aroclor or Halowax mixture instead of the individual compounds, which was impractical because of limited numbers of individual standards. A retention index database was developed with all 209 PCBs and 36 PCNs to help identify these chemicals in environmental and biological matrixes. This study uses linear and Lee retention indices to identify all 209 PCBs and 36 PCNs on nine gas chromatography columns. The most toxic congeners, the 12 dioxin-like PCBs, were compared across all columns to determine which stationary phases gave the best selectivity for those compounds. Column selectivity was also examined to determine columns for confirmatory analyses and GC×GC separations. The Rxi-17SilMS demonstrated the most drastic difference in PCB selectivity and, to a lesser extent, PCNs when compared with the other eight columns and could work as a confirmatory column or as a 2nd dimension column for GC×GC separations.

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7

Miyabe, Kanji, and Georges Guiochon. "Characterization of monolithic columns for HPLC." Journal of Separation Science 27, no. 10-11 (July 2004): 853–73. http://dx.doi.org/10.1002/jssc.200401772.

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8

Plieva, Fatima M., Jonatan Andersson, Igor Yu Galaev, and Bo Mattiasson. "Characterization of polyacrylamide based monolithic columns." Journal of Separation Science 27, no. 10-11 (July 2004): 828–36. http://dx.doi.org/10.1002/jssc.200401836.

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9

Molnarova, Katarina, and Petr Kozlík. "Comparison of Different HILIC Stationary Phases in the Separation of Hemopexin and Immunoglobulin G Glycopeptides and Their Isomers." Molecules 25, no. 20 (October 13, 2020): 4655. http://dx.doi.org/10.3390/molecules25204655.

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Protein glycosylation analysis is challenging due to the structural variety of complex conjugates. However, chromatographically separating glycans attached to tryptic peptides enables their site-specific characterization. For this purpose, we have shown the importance of selecting a suitable hydrophilic interaction liquid chromatography (HILIC) stationary phase in the separation of glycopeptides and their isomers. Three different HILIC stationary phases, i.e., HALO® penta-HILIC, Glycan ethylene bridged hybrid (BEH) Amide, and ZIC-HILIC, were compared in the separation of complex N-glycopeptides of hemopexin and Immunoglobulin G glycoproteins. The retention time increased with the polarity of the glycans attached to the same peptide backbone in all HILIC columns tested in this study, except for the ZIC-HILIC column when adding sialic acid to the glycan moiety, which caused electrostatic repulsion with the negatively charged sulfobetaine functional group, thereby decreasing retention. The HALO® penta-HILIC column provided the best separation results, and the ZIC-HILIC column the worst. Moreover, we showed the potential of these HILIC columns for the isomeric separation of fucosylated and sialylated glycoforms. Therefore, HILIC is a useful tool for the comprehensive characterization of glycoproteins and their isomers.

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10

Thiessen, Kendall J., Marolo C. Alfaro, and James A. Blatz. "Measuring the load–deformation response of rockfill columns by a full-scale field test on a natural riverbank." Canadian Geotechnical Journal 48, no. 7 (July 2011): 1032–43. http://dx.doi.org/10.1139/t11-019.

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A full-scale field test loading of a riverbank stabilized with rockfill columns was used to measure the load–deformation characteristics of the reinforced slope. The test site is located on the natural banks of the Red River in the city of Winnipeg. Rockfill column technology has evolved from granular shear key methods for stabilizing slopes. The relatively weak lacustrine clays are stabilized with compacted columns of limestone rockfill. The columns typically extend through the clay stratum and are anchored in the underlying till. The project involved an extensive site investigation, and soils characterization program in preparation for the field test. Eleven 2.1 m diameter columns were tested by loading the bank with 1920 t of fill. The deformations were measured with standard and in-place inclinometers. The pore-water pressure response of the in situ soils was continuously monitored with vibrating wire piezometers. The results have shown that shear stresses are mobilized along the entire length of the column when subjected to loading, and that complete densification is important in minimizing deformations. This paper discusses the design and construction of the field test and presents the results of the monitoring programs.

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11

Shim, Byung Young, Eun A. Ko, Dong Wook Kim, and Cheul Ro Lee. "Growth and Characterization of GaN Nano-Column Grown on Si (111) Substrate Using Au+Ga Alloy Seeding Method by MOCVD." Solid State Phenomena 124-126 (June 2007): 113–18. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.113.

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We have studied the Au+Ga alloy seeding method. Single-crystal GaN nano-column arrays were grown using metalorganic chemical vapor deposition (MOCVD) and their properties were investigated as a function of the growth parameters and Au thin film thickness. Au-coated Si(111) substrates were used for the growth of GaN nano-columns. The diameter and length of as-grown nano-column ranged from 100 to 500 nm and 1 to 5 μm, respectively. The morphology of the columns was investigated using scanning electron microscopy. Energy dispersive X-ray spectroscopy and photoluminescence were used for evaluating of its qualitative analysis and to evaluate the optical properties, respectively. Two important growth parameters were considered, the thickness of the Au thin film and the gallium flow rate. The density and tendency of the nano-columns depend on each of these growth parameters. It is believed that the catalytic activity of gold is determined by the size of the Au+Ga solid solution particles, and smaller Au+Ga clusters showed significant reactivity in the growth of one-dimensional GaN nano structures.

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12

Harries, Kent A., Michael F. Petrou, and George Brooks. "Structural Characterization of Built-Up Timber Columns." Journal of Architectural Engineering 6, no. 2 (June 2000): 58–65. http://dx.doi.org/10.1061/(asce)1076-0431(2000)6:2(58).

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13

Kossoff, D., K. A. Hudson-Edwards, W. E. Dubbin, and M. Alfredsson. "Incongruent weathering of Cd and Zn from mine tailings." Mineralogical Magazine 72, no. 1 (February 2008): 81–84. http://dx.doi.org/10.1180/minmag.2008.072.1.81.

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AbstractWeathering ofdischarged mine tailings contaminates streams, rivers and floodplains with toxic metals on a vast scale. The magnitude of the problem depends on input tailings mineralogy, storage and dispersal, and climatic conditions. To better understand the mechanisms of long-term tailings weathering, a leaching column study was established, incorporating tailings and soil from Potosí, Bolivia, with the aim of modelling a 25 year field period. The Zn/Cd molar ratio ofthe tailings leachate water, initially 738 for the unaltered tailings, is highly variable over 15 model years of leaching, particularly in the mixed tailings-soil columns. Columns with soil have ratios as high as 2563, while pure tailings columns reach ratios of <376. We employ complementary techniques, involving atomistic computational modelling, leachate analysis and mineralogical characterization, to elucidate the mechanisms governing these incongruent Cd and Zn weathering dynamics.

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14

Jaulmes, Alain, Ioannis Ignatiadis, Philippe Cardot, and Claire Vidal-Madjar. "Characterization of peak asymmetry with overloaded capillary columns." Journal of Chromatography A 395 (June 1987): 291–306. http://dx.doi.org/10.1016/s0021-9673(01)94118-4.

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15

Sander, Lane C., Catherine A. Rimmer, and Walter B. Wilson. "Characterization of triacontyl (C-30) liquid chromatographic columns." Journal of Chromatography A 1614 (March 2020): 460732. http://dx.doi.org/10.1016/j.chroma.2019.460732.

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16

Costa, Fernando Manuel da Conceição, Manuel Alberto Nogueira Henriques Rosa, Mattia Canetto, and Maria Júlia Sobral da Fonseca. "The degradation of the “Study room” (Convent of Christ, Tomar, Portugal), from a preliminary analysis towards a sustainable maintenance." Ge-conservacion 21, no. 1 (February 16, 2022): 95–107. http://dx.doi.org/10.37558/gec.v21i1.1052.

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Following a comprehensive analysis of the stone degradation of the “Study Room”, in the Crow’s Cloister west wing (Convent of Christ, Tomar, Portugal), a multiapproach plan was made to address the salt problems encountered on its limestone columns. Chemical characterization studies were made to determine the concentration and the type of the efflorescence soluble salts involved, as well as the ionic composition of the limestone material of the column, and also, in which environmental conditions their harmful activity is reduced (or prevented). Finally, on site, the existing cement mortar was removed in a 30 cm area around the base of the column, and the ionic characterization obtained was submitted to the ECOS-RUNSALT software, which determined that simply by fixing the relative humidity at 65±2%, the weathering process would be substantially reduced – conditions different from the ones encountered.

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17

Borges, Endler M. "How to select equivalent and complimentary reversed phase liquid chromatography columns from column characterization databases." Analytica Chimica Acta 807 (January 2014): 143–52. http://dx.doi.org/10.1016/j.aca.2013.11.010.

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18

Ghalehbeygi, Omid Tayefeh, Vural Kara, Levent Trabzon, Selcuk Akturk, and Huseyin Kizil. "Fabrication and Characterization of Si Nano-Columns by Femtosecond Laser." Journal of Nano Research 16 (January 2012): 15–20. http://dx.doi.org/10.4028/www.scientific.net/jnanor.16.15.

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We fabricated Si Nano-columns by a femtosecond laser with various wavelengths and process parameters, whilst the specimen was submerged in water. The experiments were carried out by three types of wavelengths i.e. 1030 nm, 515nm, 343nm, with 500 fs laser pulses. The scales of these spikes are much smaller than micro spikes that are constructed by laser irradiation of silicon surface in vacuum or gases like SF6, Cl2. The Si nano-columns of 300 nm or less in width were characterized by SEM measurements. The formation of these Si Nano-columns that were revealed by SEM observation, indicates chemical etching with laser ablation occurred when surface exposed by laser beam. We observed 200 nm spikes height at the center of laser beam profile and the ones uniform in height at lateral incident area.

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19

O’Barr, R., S. Y. Yamamoto, S. Schultz, Weihua Xu, and A. Scherer. "Fabrication and characterization of nanoscale arrays of nickel columns." Journal of Applied Physics 81, no. 8 (April 15, 1997): 4730–32. http://dx.doi.org/10.1063/1.365444.

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20

ALOthman, Zeid A. "Preparation and characterization of alkyl methacrylate capillary monolithic columns." Journal of Saudi Chemical Society 16, no. 3 (July 2012): 271–78. http://dx.doi.org/10.1016/j.jscs.2011.01.010.

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21

Baxter, Jason B., Feng Wu, and Eray S. Aydil. "Growth mechanism and characterization of zinc oxide hexagonal columns." Applied Physics Letters 83, no. 18 (November 3, 2003): 3797–99. http://dx.doi.org/10.1063/1.1624467.

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22

Tsirkin, Irena, and Eli Grushka. "Characterization of dynamically prepared phospholipid-modified reversed-phase columns." Journal of Chromatography A 919, no. 2 (June 2001): 245–54. http://dx.doi.org/10.1016/s0021-9673(01)00824-x.

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23

YING, P., and J. DORSEY. "Characterization of retentivity of reversed phase liquid chromatography columns." Talanta 38, no. 3 (March 1991): 237–43. http://dx.doi.org/10.1016/0039-9140(91)80042-x.

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24

Jandera, P., M. Halama, K. Novotná, and S. Bunčeková. "Characterization and comparison of HPLC columns for gradient elution." Chromatographia 57, S1 (January 2003): S153—S161. http://dx.doi.org/10.1007/bf02492098.

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25

Majeed, Hammad, Hanna K. Knuutila, Magne Hillestad, and Hallvard F. Svendsen. "Characterization and modelling of aerosol droplet in absorption columns." International Journal of Greenhouse Gas Control 58 (March 2017): 114–26. http://dx.doi.org/10.1016/j.ijggc.2017.01.006.

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26

Kanatyeva, Anastasiya, Alexander Korolev, Valeria Shiryaeva, Tamara Popova, and Alexander Kurganov. "Characterization of monolithic capillary columns using inverse gas chromatography." Journal of Separation Science 32, no. 15-16 (August 2009): 2635–41. http://dx.doi.org/10.1002/jssc.200900196.

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27

Hochstaffl, Philipp, and Franz Schreier. "Impact of Molecular Spectroscopy on Carbon Monoxide Abundances from SCIAMACHY." Remote Sensing 12, no. 7 (March 27, 2020): 1084. http://dx.doi.org/10.3390/rs12071084.

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High-quality observations have indicated the need for improved molecular spectroscopy for accurate atmospheric characterization. Line data provided by the new SEOM-IAS (Scientific Exploitation of Operational Missions—Improved Atmospheric Spectroscopy) database in the shortwave infrared (SWIR) region were used to retrieve CO total vertical columns from a selected set of nadir SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) observations. In order to assess the quality of the retrieval results, differences in the spectral fitting residuals with respect to the HITRAN 2016 (High-resolution TRANsmission molecular absorption) and GEISA 2015 (Gestion et Etude des Informations Spectroscopiques Atmosphériques) line lists were quantified and column-averaged dry-air CO mole fractions were compared to NDACC (Network for the Detection of Atmospheric Composition Change) and TCCON (Total Carbon Column Observing Network) ground-based measurements. In general, it was found that using SEOM-IAS line data with corresponding line models improve the spectral quality of the retrieval (smaller residuals) and increase the fitted CO columns, thereby reducing the bias to both ground-based networks.

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28

Zhou, YanQun, YeZhi Zhang, MeiXin Ye, and MengSi Zhan. "Seismic Behavior and Force-Displacement Characterization of Neotype Column-Slab High Piers." Scientific World Journal 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/653247.

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The seismic behavior and plasticity spreading of a neotype column-slab high pier are researched in this paper. Four scale model tests of a web slab with two boundary columns are carried out under cyclic inelastic lateral displacements simulating seismic response. The test results show that the neotype column-slab high pier has strong and stable bearing capacity, good ductility, and energy dissipation capacity. The experimental values pertaining to the spread of plasticity are derived. An approach for deriving the spread of plasticity analytically is deduced and applied to the four tests. This method accurately assesses a pier’s spread of plasticity for most ductility levels. At nearly all ductility levels, the mean difference between analytical assessments of the spread of plasticity and results from 4 large-scale tests is 12% with a 9% coefficient of variation.

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29

Sassa, T., and J. Miwa. "Purification and characterization of protein kinase C from the nematode Caenorhabditis elegans." Biochemical Journal 282, no. 1 (February 15, 1992): 219–23. http://dx.doi.org/10.1042/bj2820219.

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Protein kinase C (PKC) of Caenorhabditis elegans was identified by enzymatic activity and [3H]phorbol 12,13-dibutyrate binding after DEAE-Sephacel column chromatography of a crude cytosolic extract. Ca(2+)-dependent activation of nematode PKC was observed in the presence of phosphatidylserine. The enzyme was maximally activated by 1,2-dioleoylglycerol or phorbol 12-myristate 13-acetate in the presence of phosphatidylserine and Ca2+. Hydroxyapatite column chromatography showed only one peak of PKC activity with histone H1 and myelin basic protein as substrates. The enzyme was purified to near homogeneity by sequential chromatography on polylysine-agarose and phosphatidylserine affinity columns. The purified protein showed a molecular mass of 79 kDa on SDS/PAGE. The substrate specificity of the C. elegans enzyme was shown to be different from that of mammalian PKCs. Here we describe some of the properties of the nematode enzyme.

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30

Shields, Patricia A., and Samuel R. Farrah. "Characterization of Virus Adsorption by Using DEAE-Sepharose and Octyl-Sepharose." Applied and Environmental Microbiology 68, no. 8 (August 2002): 3965–68. http://dx.doi.org/10.1128/aem.68.8.3965-3968.2002.

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ABSTRACT Viruses were characterized by their adsorption to DEAE-Sepharose or by their elution from octyl-Sepharose by using buffered solutions of sodium chloride with different ionic strengths. Viruses whose adsorption to DEAE-Sepharose was reduced most rapidly by an increase in the sodium chloride concentration were considered to have the weakest electrostatic interactions with the solids; these viruses included MS2, E1, and φX174. Viruses whose adsorption to DEAE-Sepharose was reduced least rapidly were considered to have the strongest electrostatic interactions with the column; these viruses included P1, T4, T2, and E5. All of the viruses studied adsorbed to octyl-Sepharose in the presence of 4 M NaCl. Viruses that were eluted most rapidly following a decrease in the concentration of NaCl were considered to have the weakest hydrophobic interactions with the column; these viruses included φX174, CB4, and E1. Viruses that were eluted least rapidly from the columns after the NaCl concentration was decreased were considered to have the strongest hydrophobic interactions with the column; these viruses included f2, MS2, and E5.

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31

Ebihara, Tatsuji, and Paul L. Bishop. "Biofilm structural forms utilized in bioremediation of organic compounds." Water Science and Technology 39, no. 7 (April 1, 1999): 203–10. http://dx.doi.org/10.2166/wst.1999.0360.

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Various biofilm structural forms were observed and characterized in sand columns simulating groundwater aquifer conditions. The mixed microbial community utilized toluene as a sole carbon source. Sand column experiments were conducted with a linear flow velocity of 5.3 m/d and toluene feed concentration of 6 mg/L. Sand columns attained a pseudo steady-state profile for bulk liquid toluene concentration prior to biofilm characterization. Profiles of viable biomass, carbohydrate, and bulk liquid toluene concentration were obtained at 5 cm intervals from 0 to 15 cm depth. Biofilm structural forms were observed using scanning confocal laser microscopy in flow cells that duplicated conditions in the sand columns. The following classes of viable biofilm structures were observed: thin uniform films, protrusions extending from the biofilm, and thin strands of cell aggregates bridging sand grains. Viable biomass profiles indicated approximately 45 percent of the biomass was weakly attached to sand grains versus firmly attached growth held on sand grain surfaces. Biofilm structural forms provided insight into distribution of viable bacteria during aquifer bioremediation and identified opportunities for engineered processes to modify biofilm structures for the optimization of hydrophobic organic compound bioremediation in groundwater aquifers.

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32

Mihoc, Anca, and Dieter Kluepfel. "Purification and characterization of a β-glucosidase from Streptomyces lividans 66." Canadian Journal of Microbiology 36, no. 1 (January 1, 1990): 53–56. http://dx.doi.org/10.1139/m90-009.

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An intracellular β-1, 4-D-glucosidase (EC 3.2.1.21) was isolated from the mutant strain HP-3 of Streptomyces lividans 66 which produced about 12 times more enzyme than the wild-type strain. The purification was carried out by anion exchange column chromatography followed by high-performance liquid chromatography on DEAE and on molecular sieve columns. The enzyme is glycosylated and has an apparent Mr of 51 000 and a pI of 4.3. Its activity was optimal at pH 6.5 and at a temperature of 40 °C. The Km and the Vmax on cellobiose were 3.1 mM and 65.6 μmol min−1 mg−1 of enzyme. Key words: β-glucosidase, Streptomyces lividans, purification, characterization.

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33

Mercado-Flores, Yuridia, Adriana Trejo-Aguilar, Bernardo Ramírez-Zavala, Lourdes Villa-Tanaca, and César Hernández-Rodríguez. "Purification and characterization of an intracellular aspartyl acid proteinase (pumAi) from Ustilago maydis." Canadian Journal of Microbiology 51, no. 2 (February 1, 2005): 171–75. http://dx.doi.org/10.1139/w04-125.

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The intracellular proteinase pumAi in Ustilago maydis has been associated with yeast-mycelium dimorphic transition. The proteinase was purified from a cell-free extract by ammonium sulfate fractionation and chromatographic steps including hydrophobic interactions on a Phenyl Superose column, ion exchange on a Mono Q column, and gel filtration on Superose 12 columns. The enzyme has a mass of 35.3–36.6 kDa, a pH and temperature optimum of 4.0 and 40 °C, respectively, and a pI of 5.5. The enzyme degraded hemoglobin, gelatin, albumin, and casein, but not collagen, and the enzymatic activity was strongly inhibited by pepstatin A, an aspartyl proteinase-specific inhibitor. The biochemical characteristics of pumAi are similar to other fungal intracellular aspartyl proteinases, however, this is the first biochemical characterization of a basidiomycete proteinase probably associated with dimorphic yeast-mycelium transition.Key words: aspartyl proteinase, yeast-mycelium transition, Ustilago maydis.

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34

Lerot, Christophe, François Hendrick, Michel Van Roozendael, Leonardo M. A. Alvarado, Andreas Richter, Isabelle De Smedt, Nicolas Theys, et al. "Glyoxal tropospheric column retrievals from TROPOMI – multi-satellite intercomparison and ground-based validation." Atmospheric Measurement Techniques 14, no. 12 (December 10, 2021): 7775–807. http://dx.doi.org/10.5194/amt-14-7775-2021.

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Abstract. We present the first global glyoxal (CHOCHO) tropospheric column product derived from the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5 Precursor satellite. Atmospheric glyoxal results from the oxidation of other non-methane volatile organic compounds (NMVOCs) and from direct emissions caused by combustion processes. Therefore, this product is a useful indicator of VOC emissions. It is generated with an improved version of the BIRA-IASB scientific retrieval algorithm relying on the differential optical absorption spectroscopy (DOAS) approach. Among the algorithmic updates, the DOAS fit now includes corrections to mitigate the impact of spectral misfits caused by scene brightness inhomogeneity and strong NO2 absorption. The product comes along with a full error characterization, which allows for providing random and systematic error estimates for every observation. Systematic errors are typically in the range of 1 ×1014–3 ×1014 molec. cm−2 (∼30 %–70 % in emission regimes) and originate mostly from a priori data uncertainties and spectral interferences with other absorbing species. The latter may be at the origin, at least partly, of an enhanced glyoxal signal over equatorial oceans, and further investigation is needed to mitigate them. Random errors are large (>6×1014 molec. cm−2) but can be reduced by averaging observations in space and/or time. Benefiting from a high signal-to-noise ratio and a large number of small-size observations, TROPOMI provides glyoxal tropospheric column fields with an unprecedented level of detail. Using the same retrieval algorithmic baseline, glyoxal column data sets are also generated from the Ozone Monitoring Instrument (OMI) on Aura and from the Global Ozone Monitoring Experiment-2 (GOME-2) on board Metop-A and Metop-B. Those four data sets are intercompared over large-scale regions worldwide and show a high level of consistency. The satellite glyoxal columns are also compared to glyoxal columns retrieved from ground-based Multi-AXis DOAS (MAX-DOAS) instruments at nine stations in Asia and Europe. In general, the satellite and MAX-DOAS instruments provide consistent glyoxal columns both in terms of absolute values and variability. Correlation coefficients between TROPOMI and MAX-DOAS glyoxal columns range between 0.61 and 0.87. The correlation is only poorer at one mid-latitude station, where satellite data appear to be biased low during wintertime. The mean absolute glyoxal columns from satellite and MAX-DOAS generally agree well for low/moderate columns with differences of less than 1×1014 molec. cm−2. A larger bias is identified at two sites where the MAX-DOAS columns are very large. Despite this systematic bias, the consistency of the satellite and MAX-DOAS glyoxal seasonal variability is high.

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35

Hildebrant, Benjamin, Arnaud Igor Ndé-Tchoupé, Mesia Lufingo, Tobias Licha, and Chicgoua Noubactep. "Steel Wool for Water Treatment: Intrinsic Reactivity and Defluoridation Efficiency." Processes 8, no. 3 (February 26, 2020): 265. http://dx.doi.org/10.3390/pr8030265.

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Studies were undertaken to characterize the intrinsic reactivity of Fe0-bearing steel wool (Fe0 SW) materials using the ethylenediaminetetraacetate method (EDTA test). A 2 mM Na2-EDTA solution was used in batch and column leaching experiments. A total of 15 Fe0 SW specimens and one granular iron (GI) were tested in batch experiments. Column experiments were performed with four Fe0 SW of the same grade but from various suppliers and the GI. The conventional EDTA test (0.100 g Fe0, 50 mL EDTA, 96 h) protocol was modified in two manners: (i) Decreasing the experimental duration (down to 24 h) and (ii) decreasing the Fe0 mass (down to 0.01 g). Column leaching studies involved glass columns filled to 1/4 with sand, on top of which 0.50 g of Fe0 was placed. Columns were daily gravity fed with EDTA and effluent analyzed for Fe concentration. Selected reactive Fe0 SW specimens were additionally investigated for discoloration efficiency of methylene blue (MB) in shaken batch experiments (75 rpm) for two and eight weeks. The last series of experiments tested six selected Fe0 SW for water defluoridation in Fe0/sand columns. Results showed that (i) the modifications of the conventional EDTA test enabled a better characterization of Fe0 SW; (ii) after 53 leaching events the Fe0 SW showing the best kEDTA value released the lowest amount of iron; (iii) all Fe0 specimens were efficient at discoloring cationic MB after eight weeks; (iv) limited water defluoridation by all six Fe0 SW was documented. Fluoride removal in the column systems appears to be a viable tool to characterize the Fe0 long-term corrosion kinetics. Further research should include correlation of the intrinsic reactivity of SW specimens with their efficiency at removing different contaminants in water.

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36

Olivelli, Melisa Soledad, Daniel Di Gregorio, Hugo Huck, Jorge Fernández Niello, Rosa María Torres Sánchez, and Gustavo Curutchet. "Characterization of U(VI) Sorption and Leaching on Clay Supported Biomass Sorbents." Advanced Materials Research 825 (October 2013): 532–35. http://dx.doi.org/10.4028/www.scientific.net/amr.825.532.

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In previous studies was demonstrated that matrixes generated from fungal biomass and a montmorillonite (BMMTs) are efficient as biosorbentes in batch uranium removal systems. The objective of this article is to evaluate the U(VI) sorption capacity of BMMT in continuous systems for its removal from effluents and to determine the reusability of the sorbent and the recovery of the uranium testing different leaching solutions. Upflow BMMT columns were performed in order to optimize the system for continuous sorption techniques. For upflow columns, the maximum total amount of U(VI) retained was 75 mg U(VI) / g BMMT. Treatment of U(VI) loaded BMMTs with leaching solutions allowed calculating U(VI) extraction percentages. These results indicated the possibility of recycling the sorbent after processes of U(VI) sorption and that the use of clay supported biomass sorbents in upflow columns presented strong potential for uranium retention.

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Pruden, A., H. Hong, L. Inman, M. Logan, C. Sans, D. Ahmanna, L. Figueroa, and K. Reardon. "Microbial Characterization of Sulfate-Reducing Columns Remediating Acid Mine Drainage." Journal American Society of Mining and Reclamation 2005, no. 1 (2005): 935–44. http://dx.doi.org/10.21000/jasmr05010935.

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38

Povoli, M., C. Betancourt, M. Boscardin, G. F. Dalla Betta, G. Giacomini, B. Lecini, S. Kuehn, U. Parzefall, and N. Zorzi. "Characterization of 3D-DDTC strip sensors with passing-through columns." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 730 (December 2013): 38–43. http://dx.doi.org/10.1016/j.nima.2013.04.064.

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Massinaei, M., M. Kolahdoozan, M. Noaparast, M. Oliazadeh, J. Yianatos, R. Shamsadini, and M. Yarahmadi. "Hydrodynamic and kinetic characterization of industrial columns in rougher circuit." Minerals Engineering 22, no. 4 (March 2009): 357–65. http://dx.doi.org/10.1016/j.mineng.2008.10.003.

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Jiang, T., J. Jiskra, H. A. Claessens, and C. A. Cramers. "Preparation and characterization of monolithic polymer columns for capillary electrochromatography." Journal of Chromatography A 923, no. 1-2 (July 2001): 215–27. http://dx.doi.org/10.1016/s0021-9673(01)00982-7.

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Jandera, Pavel, and Kateřina Novotná. "Characterization of High‐Pressure Liquid Chromatography Columns using Chromatographic Methods." Analytical Letters 39, no. 10 (August 2006): 2095–152. http://dx.doi.org/10.1080/00032710600773424.

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Adhami, Mohsen, Niloufar Jamshidi, Reza Zarghami, and Navid Mostoufi. "Characterization of hydrodynamics of bubble columns by recurrence quantification analysis." Chaos, Solitons & Fractals 111 (June 2018): 213–26. http://dx.doi.org/10.1016/j.chaos.2018.04.011.

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43

Podgornik, A., J. Vidič, J. Jančar, N. Lendero, V. Frankovič, and A. Štrancar. "Noninvasive Methods for Characterization of Large-Volume Monolithic Chromatographic Columns." Chemical Engineering & Technology 28, no. 11 (November 2005): 1435–41. http://dx.doi.org/10.1002/ceat.200500170.

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44

Cantó‐Mirapeix, Amparo, José M. Herrero‐Martínez, Carlos Mongay‐Fernández, and Ernesto F. Simó‐Alfonso. "Preparation and characterization of hexyl methacrylate monolithic columns for CEC." ELECTROPHORESIS 29, no. 18 (September 2008): 3866–74. http://dx.doi.org/10.1002/elps.200800154.

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Zhang, Kai, Chao Yan, Junjiao Yang, Zhichao Zhang, Qinsun Wang, and Ruyu Gao. "Preparation and characterization of C16 monolithic columns for capillary electrochromatography." Journal of Separation Science 28, no. 3 (February 2005): 217–24. http://dx.doi.org/10.1002/jssc.200401873.

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46

McKernan, Stuart, and C. Barry Carter. "Characterization of structural units in tilt grain boundaries." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 120–21. http://dx.doi.org/10.1017/s0424820100121004.

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General tilt grain boundaries can be viewed in terms of small structural units of varying complexity. High-resolution electron microscope (HREM) images of these boundaries in many materials show this repetitive similarity of the atomic structure at the boundary plane. The structure of particular grain boundaries has been examined for several special cases and commonly observed configurations include symmetric tilt grain boundaries and asymmetric tilt grain boundaries with one grain having a prominent, low-index facet. Several different configurations of the boundary structure may possibly occur, even in the same grain boundary. There are thus many possible ways to assemble the basic structural units to form a grain boundary. These structural units and their distribution have traditionally been examined by high-resolution electron microscopy. The images of the projection of the atomic columns (or the tunnels between atomic columns) providing a template for constructing “ball-and-stick ” models of the interface.

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McGibbon, M. M., N. D. Browning, M. F. Chisholm, A. J. McGibbon, S. J. Pennycook, V. Ravikumar, and V. P. Dravid. "Atomic-resolution characterization of an SrTiO3 grain boundary in the STEM." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 972–73. http://dx.doi.org/10.1017/s0424820100172590.

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High-resolution Z-contrast imaging in the scanning transmission electron microscope (STEM) forms an incoherent image in which changes in atomic structure and composition across an interface can be interpreted intuitively without the need for preconcieved atomic structure models. Since the Z-contrast image is formed by electrons scattered through high angles, parallel detection electron energy loss spectroscopy (PEELS) can be used simultaneously to provide complementary chemical information on an atomic scale. The fine structure in the PEEL spectra can be used to investigate the local electronic structure and the nature of the bonding across the interface. In this paper we use the complimentary techniques of high resolution Z-contrast imaging and PEELS to investigate the atomic structure and chemistry of a 25 degree symmetric tilt boundary in a bicrystal of the electroceramic SrTiO3.Figure 1(a) shows a Z-contrast image of a symmetric region of the tilt boundary. The brightest spots in the image correspond to the increased scattering power of the Sr atomic columns (Z=38) with theless bright spots corresponding to the Ti atomic columns (Z=22). The lighter O atomic columns are notvisible in a Z-contrast image.

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48

Undin, Torgny, Jörgen Samuelsson, Anders Törncrona, and Torgny Fornstedt. "Evaluation of a combined linear-nonlinear approach for column characterization using modern alkaline-stable columns as model." Journal of Separation Science 36, no. 11 (June 2013): 1753–61. http://dx.doi.org/10.1002/jssc.201201132.

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Penha, Taiane Rodrigues, Jenifer Rigo Almeida, Rafael Mantovaneli Sousa, Eustáquio Vinicius Ribeiro de Castro, Maria Tereza Weitzel Dias Carneiro, and Geisamanda Pedrini Brandão. "Multielement analysis of crude oil produced water by ICP OES after acid digestion assisted by microwave." Journal of Analytical Atomic Spectrometry 30, no. 5 (2015): 1154–60. http://dx.doi.org/10.1039/c4ja00322e.

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Crude oil produced water characterization is important because its disposal or reuse is difficult: environmental impacts (high salinity and toxic components) or risk of obstruction on the production columns (crust formation).

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50

Van Damme, M., L. Clarisse, C. L. Heald, D. Hurtmans, Y. Ngadi, C. Clerbaux, A. J. Dolman, J. W. Erisman, and P. F. Coheur. "Global distributions, time series and error characterization of atmospheric ammonia (NH<sub>3</sub>) from IASI satellite observations." Atmospheric Chemistry and Physics 14, no. 6 (March 21, 2014): 2905–22. http://dx.doi.org/10.5194/acp-14-2905-2014.

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Abstract. Ammonia (NH3) emissions in the atmosphere have increased substantially over the past decades, largely because of intensive livestock production and use of fertilizers. As a short-lived species, NH3 is highly variable in the atmosphere and its concentration is generally small, except near local sources. While ground-based measurements are possible, they are challenging and sparse. Advanced infrared sounders in orbit have recently demonstrated their capability to measure NH3, offering a new tool to refine global and regional budgets. In this paper we describe an improved retrieval scheme of NH3 total columns from the measurements of the Infrared Atmospheric Sounding Interferometer (IASI). It exploits the hyperspectral character of this instrument by using an extended spectral range (800–1200 cm−1) where NH3 is optically active. This scheme consists of the calculation of a dimensionless spectral index from the IASI level1C radiances, which is subsequently converted to a total NH3 column using look-up tables built from forward radiative transfer model simulations. We show how to retrieve the NH3 total columns from IASI quasi-globally and twice daily above both land and sea without large computational resources and with an improved detection limit. The retrieval also includes error characterization of the retrieved columns. Five years of IASI measurements (1 November 2007 to 31 October 2012) have been processed to acquire the first global and multiple-year data set of NH3 total columns, which are evaluated and compared to similar products from other retrieval methods. Spatial distributions from the five years data set are provided and analyzed at global and regional scales. In particular, we show the ability of this method to identify smaller emission sources than those previously reported, as well as transport patterns over the ocean. The five-year time series is further examined in terms of seasonality and interannual variability (in particular as a function of fire activity) separately for the Northern and Southern Hemispheres.

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