Articles de revues : « Sp-filtration »

1

Crabb, M. C., et S. A. Mitchell. « The loops onU(n)/O(n) andU(2n)/Sp(n) ». Mathematical Proceedings of the Cambridge Philosophical Society 104, n^o 1 (juillet 1988) : 95–103. http://dx.doi.org/10.1017/s0305004100065269.

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In [6] and [9] the second author and Bill Richter showed that the natural ‘degree’ filtration on the homology of ΩSU(n) has a geometric realization, and that this filtration stably splits (as conjectured by M. Hopkins and M. Mahowald). The purpose of the present paper is to prove the real and quaternionic analogues of these results. To explain what this means, consider the following two ways of viewing the filtration and splitting for ΩSU(n). Whenn= ∞, ΩSU=BU. The filtration isBU(1)⊆BU(2)⊆… and the splittingBU≅ V1≤<∞is a theorem of Snaith[14]. The result for ΩSU(n) may then be viewed as a ‘restriction’ of the result forBU. On the other hand there is a well-known inclusion ℂPn−1. This extends to a map ΩΣℂPn−1→ΩSU(n), and the filtration (or splitting) may be viewed, at least algebraically, as a ‘quotient’ of the James filtration (or splitting) of ΩΣℂPn−1. It is now clear what is meant by the ‘real and quaternionic analogues’. In the quaternionic case, we replaceBUbyBSp=Ω(SU/SP), ΩSU(n) by Ω(SU(2n)/SP(n))and ℂPn−1by ℍPn−1. The integral homology of Ω(SU(2n)/SP(n)) is the symmetric algebra on the homology of ℍPn−1, and may be filtered by the various symmetric powers. We show that this filtration can be realized geometrically, and that the spaces of the filtration are certain (singular) real algebraic varieties (exactly as in the complex case). The strata of the filtration are vector bundles over filtrations of Ω(SU(2n−2)/SP(n−1)), and the filtration stably splits. See Theorems (1·7) and (2·1) for the precise statement. In the real case we replaceBUby Ω(SU/SO), Ω(SU(n)/SO(n)) and ℂPn−1by ℝPn−1. Here integral homology must be replaced by mod 2 homology, and splitting is only obtained after localization at 2. (Snaith's splitting ofBOin [14] can be refined [2, 8] so as to be exactly analogous to the splitting ofBU:BO≅V1≤<∞MO(k).)

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Brower, James C. « Systematics and paleoecology of Haptocrinus buttsi, a new species of disparid crinoid from the Upper Ordovician Hatter Limestone of central Pennsylvania ». Journal of Paleontology 82, n^o 3 (mai 2008) : 576–84. http://dx.doi.org/10.1666/07-098.1.

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Three crinoids are known from the Upper Ordovician Hatter Limestone at Union Furnace in central Pennsylvania, i.e., Haptocrinus buttsi n. sp., an unknown crinoid with a lichenocrinid holdfast, and an indeterminate columnal that probably belongs to a crinoid. Two crowns enable H. buttsi n. sp. to be reconstructed. The animal lived about 70 cm above the seafloor and was attached to a strophomenid brachiopod with a lichenocrinid holdfast. Its endotomous arms formed an efficient filtration net that covered much of the water within its planar filtration fan. The application of filtration theory indicates that H. buttsi n. sp. could begin to feed at a comparatively low ambient current velocity and balance its energy budget. Like many other ramulate disparids, H. buttsi n. sp. mainly collected moderately small food particles. As a member of the Tornatilicrinidae, H. buttsi n. sp. is a relatively primitive disparid. Another crinoid taxon bears a longer and thinner stem and a different type of lichenocrinid holdfast cemented to the same strophomenid shell. A third species, most likely a crinoid, is represented by a single columnal. The fauna lived in a quiet water lagoonal area, which is an unusual habitat for Paleozoic crinoids.

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Shevnin, V. A. « IDENTIFICATION OF SELF-POTENTIAL ANOMALIES OF DIFFUSION-ADSORPTION ORIGIN ». Moscow University Bulletin. Series 4. Geology, n^o 2 (28 avril 2018) : 93–98. http://dx.doi.org/10.33623/0579-9406-2018-2-93-98.

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Diffusion and adsorption (DA) potentials are frequently the sources of self-potential anomalies, but they not arouse such practical interest as anomalies of red-ox and filtration origin. DA anomalies can be found everywhere and geophysicists sometimes make mistakes considering DA anomalies as examples of filtration anomalies. Identification of DA anomalies is based on correlation of SP and apparent resistivity values along the same profiles. At MSU students geophysical practice in Kaluga region we obtained profiles with SP and resistivity anomalies with good correlation between them. That fact allows consider such SP anomalies as a result of DA processes.

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Kim, Dong-Yeon, Taewoon Hwang, You-Kwan Oh et Jong-In Han. « Harvesting Chlorella sp. KR-1 using cross-flow electro-filtration ». Algal Research 6 (octobre 2014) : 170–74. http://dx.doi.org/10.1016/j.algal.2014.10.004.

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Ding, Linxian, Taketo Hirose et Akira Yokota. « Amycolatopsis echigonensis sp. nov. and Amycolatopsis niigatensis sp. nov., novel actinomycetes isolated from a filtration substrate ». International Journal of Systematic and Evolutionary Microbiology 57, n^o 8 (1 août 2007) : 1747–51. http://dx.doi.org/10.1099/ijs.0.64791-0.

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The taxonomic position of two actinomycete strains, LC2T and LC11T, isolated from a filtration substrate made from Japanese volcanic soil, was determined using a polyphasic approach. The strains grew at temperatures from 5 to 45 °C, on media of pH between 6 and 11 and in the presence of 7 % NaCl. The major menaquinone was MK-9(H4). The major fatty acid was iso-C16 : 0. A phylogenetic tree based on 16S rRNA gene sequences showed that the two strains formed a distinct evolutionary lineage within the genus Amycolatopsis. On the basis of their morphological, physiological and genotypic characteristics, the isolates are proposed to represent two novel species of the genus Amycolatopsis, for which the names Amycolatopsis echigonensis sp. nov. (type strain LC2T =IAM 15387T =CCTCC AB206019T), and Amycolatopsis niigatensis sp. nov. (type strain LC11T =IAM 15388T =CCTCC AB206020T) are proposed.

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Afifi, Azzam, Abdel-Aziz Ahmed, Yassir Sulieman, Zakaria Mohamed et Theerakamol Pengsakul. « EVALUATION OF SOME MICROSCOPIC TECHNIQUES FOR DETECTING BILHARZIA AND INTESTINAL PARASITES ». International Journal of Research -GRANTHAALAYAH 4, n^o 7 (31 juillet 2016) : 185–95. http://dx.doi.org/10.29121/granthaalayah.v4.i7.2016.2611.

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The objective of the present study was to evaluate the efficacy of five different diagnostic techniques (haematouria, macro-haematouria, syringe filtration, vacuum flask filtration and sedimentation) in the detection of urinary schistosomiasis. Likewise, five techniques (direct smear, cellophane thick smear, ether-formalin, modified Kato-template and modified Kato-syringe) techniques used in the detection of intestinal schistosomiasis and other intestinal parasites were evaluated using fecal samples. The results showed that the most efficient diagnostic technique for fecal samples is the modified Kato-Katz technique, while the ether-formalin method was the most sensitive tool for the detection of Schistosoma mansoni, Enterobius sp. and Ascaris sp. rates of infection and worm burden. The modified Kato techniques (template and syringe) failed to detect the intestinal protozoa, Giardia lamblia and Entamoeba histolytica, while the syringe filtration technique was the most powerful urine test.

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Kong, Ying Ying, Meng Liu, Wei Di, Cong Wang, Ming Du et Lan Wei Zhang. « Purification and Identification of Lactoferrin from Bovine Milk ». Advanced Materials Research 524-527 (mai 2012) : 2290–93. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.2290.

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Lactoferrin has many kinds of bioactivities which have attracted more and more attention. In the present study, lactoferrin from bovine milk was isolated and purified by membrane filtration, series of chromatography on SP Sepharose Big Bead ion exchange column and Superdex 200 gel filtration column. The purified lactoferrin was identified by SDS-PAGE compared with the lactoferrin standard.

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Watson, Nikki A., et Klaus Rohde. « Novel Protonephridial Filtration Apparatus in Cylindrostoma fingalianum, Allostoma sp. and Pseudostomum quadrioculatum (Platyhelminthes : Prolecithophora) ». Australian Journal of Zoology 45, n^o 6 (1997) : 621. http://dx.doi.org/10.1071/zo97043.

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The diverse types of protonephridial filtration apparatus in the Platyhelminthes provide valuable characters for phylogenetic resolution, yet only one species from the order Prolecithophora has previously been studied. We examined three further species, two belonging to the family Cylindrostomidae and one from the Pseudostomidae, and found a novel arrangement consisting of scattered, short filtration slits in the cytoplasmic cylinder of the terminal cell surrounding the flame of cilia. In these species there are no regular, longitudinal ‘ribs’, such as are found in many other platyhelminth taxa, nor bundles of supporting microtubules in the cylinder wall, and cilia arise at various levels throughout the long terminal cell column rather than in a group at the base of the flame, as is found in most other taxa. The perikaryon lies adjacent to the flame, the wall surrounding the lumen is strengthened by long, cross-striated ciliary rootlets, and the terminal cell is joined to the proximal canal by a septate junction. This simple type of filtration structure bears some resemblance to that found in Tricladida, but is distinctly different from that described in another prolecithophoran, Archimonotresis limophila (Protomonotresidae). This suggests that there may be a fundamental division within the Prolecithophora with regard to protonephridial filtration structures.

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Nitoda, Teruhiko, Hirokazu Usuki et Hiroshi Kanzaki. « A Potent Insect Chitinase Inhibitor of Fungal Origin ». Zeitschrift für Naturforschung C 58, n^o 11-12 (1 décembre 2003) : 891–94. http://dx.doi.org/10.1515/znc-2003-11-1226.

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Abstract A water-soluble polysaccharide was isolated from the culture filtrate of a fungal strain, Sphaeropsis sp. TNPT116-Cz, as a novel insect chitinase inhibitor. It was purified to chromatographic homogeneity by ethanol precipitation, anion-exchange and gel filtration chromatography. Its molecular weight was estimated to be 16 kDa by gel filtration HPLC. Monosaccharide analysis showed that it contained glucose, galactose, N-acetylglucosamine and a deoxysugar. This polysaccharide showed potent and specific inhibitory activity against Spodoptera litura chitinase with an IC50 value of 28 nᴍ.

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Al-Wasify, Raed S., Mohamed N. Ali et Shimaa R. Hamed. « Biodegradation of dairy wastewater using bacterial and fungal local isolates ». Water Science and Technology 76, n^o 11 (2 septembre 2017) : 3094–100. http://dx.doi.org/10.2166/wst.2017.481.

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Abstract Dairy wastewater contains high levels of organics and other pollutants. The present study was carried out to investigate the biodegradation process of dairy effluents using some locally isolated bacteria and fungi. Four different dairy effluent samples were collected from Obour and 6th October industrial cities, Egypt. Five bacterial species (Pseudomonas aeruginosa, Bacillus subtilis, Lactobacillus delbrueckii, Staphylococcus aureus and Enterococcus hirae) and three fungal strains (Alternaria sp., Fusarium sp. and Aspergillus sp.) were isolated from dairy wastewater samples, identified and used for biodegradation process. Bacterial and fungal consortia were prepared separately in the laboratory. Two-stages (aeration and filtration) laboratory scale model was designed. Rice straw and activated carbon layers were used as filtration media. Results indicated the great ability of both studied bacteria and fungi for removal of organics (biological oxygen demand removal percent were 78.7% and 74.7% for bacteria and fungi, respectively) and the improvement of the physicochemical quality (total suspended solids removal percent were 99.3% and 99.0% for bacteria and fungi, respectively) of the dairy effluent. The addition of rice straw and activated carbon increased removal efficiencies. Biodegradation of dairy wastewater depending on local microorganisms is an effective, cheap and eco-friendly technology.

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Augusto, Luis, Karine Le Blay, Genevieve Auger, Didier Blanot et Richard Chaby. « Interaction of bacterial lipopolysaccharide with mouse surfactant protein C inserted into lipid vesicles ». American Journal of Physiology-Lung Cellular and Molecular Physiology 281, n^o 4 (1 octobre 2001) : L776—L785. http://dx.doi.org/10.1152/ajplung.2001.281.4.l776.

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Infection of the respiratory tract is a frequent cause of lung pathologies, morbidity, and death. When bacterial endotoxin [lipopolysaccharide (LPS)] reaches the alveolar spaces, it encounters the lipid-rich surfactant that covers the epithelium. Although binding of hydrophilic surfactant protein (SP) A and SP-D with LPS has been established, nothing has been reported to date on possible cross talks between LPS and hydrophobic SP-B and SP-C. We designed a new binding technique based on the incorporation of surfactant components to lipid vesicles and the separation of unbound from vesicle-bound LPS on a density gradient. We found that among the different hydrophobic components of mouse surfactant separated by gel filtration or reverse-phase HPLC, only SP-C exhibited the capacity to bind to a tritium-labeled LPS. The binding of LPS to vesicles containing SP-C was saturable, temperature dependent, related to the concentrations of SP-C and LPS, and inhibitable by distinct unlabeled LPSs. Unlike SP-A and SP-D, the binding of SP-C to LPS did not require calcium ions. This LPS binding capacity of SP-C may represent another antibacterial defense mechanism of the lung.

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Naiola, Elidar, et Nunuk Widhyastuti. « SEMI PURIFIKASI DAN KARAKTERISASI ENZIM PROTEASE Bacillus sp. » Berkala Penelitian Hayati 13, n^o 1 (31 décembre 2007) : 51–56. http://dx.doi.org/10.23869/bphjbr.13.1.20078.

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The aim of the research was to find the partial purified of enzyme protease from Bacillus sp. The crude enzyme of protease was produce in rice brand medium (100 gram of rice brand in a liter tofu liquid waste). The enzyme was semi-purified by the procedure of precipitation using ethanol in different percentages of saturation, gel filtration using Sephadex G 100 and Ion Exchanged Chromatography using DEAE Sephadex A50. Specific activities of the enzyme during purification were 5.71 U/mg (crude enzyme); 6.75 U/mg (ethanol precipitations); 37.16 U/mg (gel filtration) and 43.02 U/mg (Ion Exchanged Chromatography). The optimum temperature for enzyme reaction was 45–50 °C, while the optimum pH was 7.0–8.0. Protease was relatively stable after heating until 37–50 °C for 60 minutes. Metal ions had different effects to the enzyme. CaCl2, FeCl3, MnCl2, ZnCl2 and MgCl2 increased enzyme activity, CdCl2 and HgCl2 gave an inhibitory effect, and another of metal ions had no effects to the enzyme.

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Miyoshi, Manoka, Shintaro Morisada, Keisuke Ohto et Hidetaka Kawakita. « Recovery of Filtered Particles by Elastic Flat-Sheet Membrane with Cross Flow ». Membranes 11, n^o 2 (20 janvier 2021) : 71. http://dx.doi.org/10.3390/membranes11020071.

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After filtration, filtered residue is recovered by a spoon, during which, the structure of the residue is destroyed, and the activity of the microorganism would be reduced. Thus, a more efficient recovery method of filtered residue is required. This study addressed the recovery method of filtered residue by the restoration of an elastic membrane, followed by cross flow. An elastic membrane composed of a copolymer of poly(ethylene glycol) diacrylate and polyacrylonitrile was prepared by photopolymerization. The pore diameter of the obtained membrane was about 10 μm. Silica particle (1 and 10 μm) and Nannochloropsis sp. (2 μm) suspension was filtered, demonstrating that silica particles of 10 μm were filtered perfectly, whereas the filtration percentage of 1 μm silica particles and Nannochloropsis sp. was lower. After the filtration, the applied pressure was released to restore the elastic membrane which moved the filtered particles up, then the filtered residue was recovered by cross flow above the membrane, demonstrating that 71% of the filtered 10 μm silica particles was recovered. The elastic behavior of the membrane, along with the cross flow, has the potential to be used as a technique for the recovery of the filtered residues. This proposed scheme would be used for the particle recovery of ceramics, cells, and microorganisms from a lab scale to a large-scale plant.

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Thayanukul, Parinda, Futoshi Kurisu, Ikuro Kasuga et Hiroaki Furumai. « Characterization of bacterial isolates from water reclamation systems on the basis of substrate utilization patterns and regrowth potential in reclaimed water ». Water Science and Technology 68, n^o 7 (1 octobre 2013) : 1556–65. http://dx.doi.org/10.2166/wst.2013.395.

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Microbial regrowth causes problems during water reuse. Comprehensive understanding of the microorganisms that can regrow in reclaimed water and their substrate requirements are necessary. In this study, potential regrowth organisms were isolated from seven water reclamation plants in Japan. Based on 16S rDNA analysis, the isolates were grouped into 34 operational taxonomic units, belonging to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Substrate utilization profiling using Biolog microplate™ classified the isolates into four groups. Bacteria in Cluster 1 (e.g., Methylobacterium sp. and Acinetobacter sp.) mainly utilized polymers, esters, amides, and alcohol. Isolates in Cluster 2 (e.g., Flavobacterium sp. and Microbacterium sp.) preferred to utilize polymers, carbohydrates, and esters. Isolates in Cluster 3 (e.g., Pseudomonas sp. and Acidovorax sp.) mainly utilized esters, carboxylic acids, and amino acids. Isolates in Cluster 4 (e.g., Enterobacter sp. and Rhodococcus sp.) utilized carbohydrates, esters, and amino acids. All isolates grew in reclaimed water treated by sand filtration, whereas some isolates could not grow in reclaimed water treated by coagulation and ozonation. Most bacteria in the same Biolog clusters exhibited similar growth characteristics in water samples. The potential of bacteria to regrow in reclaimed water likely depended on substrate requirement.

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Honda, H., T. Kudo, Y. Ikura et K. Horikoshi. « Two types of xylanases of alkalophilic Bacillus sp. No. C-125 ». Canadian Journal of Microbiology 31, n^o 6 (1 juin 1985) : 538–42. http://dx.doi.org/10.1139/m85-100.

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One alkalophilic Bacillus sp. strain C-125 (FERM No. 7344) was isolated from soil. From this organism, two types of xylanases, designated xylanase A and xylanase N, were purified by an ammonium sulfate precipitation followed by Biogel P-30 gel filtration, DEAE-cellulose chromatography, and Sephadex G-75 gel filtration. The molecular weights of xylanase A and N were estimated as 43 000 and 16 000, respectively. Immunological experiments indicated that xylanase A and xylanase N were entirely different protein molecules. Xylanase N was most active at pH 6.0–7.0, but xylanase A had a very broad pH activity curve (pH 6–10) and was still active even at pH 12.0. The maximum hydrolysis of xylan by the enzymes was about 25%. Both enzymes split xylan and yielded xylobiose and higher oligosaccharides but could hydrolyze neither xylobiose nor xylotriose. Trans xylosidation activities were detected in both enzymes.

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Kang, Seongkyun, Sangwoo Kim et Jinwon Lee. « Optimization of cross flow filtration system for Dunaliella tertiolecta and Tetraselmis sp. microalgae harvest ». Korean Journal of Chemical Engineering 32, n^o 7 (6 mars 2015) : 1377–80. http://dx.doi.org/10.1007/s11814-014-0343-5.

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Min, In-hong, et Am Jang. « A Study on Removal of Synedra sp. by using DAF System in Filtration-Basin ». Journal of Korean Society of Environmental Engineers 41, n^o 2 (28 février 2019) : 76–81. http://dx.doi.org/10.4491/ksee.2019.41.2.76.

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Khalil Abubakar, Ibrahim, Mustapha Mohammed Abubakar et Muhammad M. Abubakar. « Assessment of the Coliform Bacterial Load of Some Drinking Water Sources in Dutse Metropolis of Jigawa State Nigeria ». Scientific Review, n^o 66 (25 juin 2020) : 48–52. http://dx.doi.org/10.32861/sr.66.48.52.

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Drinking water samples from 5 sachet water companies, 3 boreholes and 2 taps, collected from different locations of Dutse Metropolis of Jigawa State, Nigeria were analysed for coliform bacterial counts using the Membrane Filtration Technique. All the samples contained some amounts of total coliforms, but mostly within permissible levels. Thirty three percent (33%) of the samples from borehole, 60% from sachet water and 100% from the taps contained faecal coliforms, which indicates contamination. Cultures of the faecal coliforms obtained were morphologically identified using the gram-staining procedure and some series of biochemical tests were carried out in order to identify the organisms. The identified organisms were Escherichia coli (E. coli), Klebsiella sp. and Citrobacter sp. Presence of coliforms above the regulatory set standards indicates contamination and un-safeness of the water for drinking. Presence of organisms such as E. coli, Klebsiella sp. and Citrobacter sp. necessitates improvement in monitoring and water hygiene practices to improve the quality of drinking water in the study area.

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Lammek, Bernard, Zbigniew Maćkiewicz, Izabela Derdowska, Hanna Świderska, Adam Nowosławski et Gotfryd Kupryszewski. « Synthesis of hepatitis B surface antigen pre-S2 region fragments and studies on their immunogenicity ». Collection of Czechoslovak Chemical Communications 53, n^o 11 (1988) : 2952–56. http://dx.doi.org/10.1135/cccc19882952.

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Two peptide fragments of hepatitis B surface antigen pre-S2 region were synthesized by the solid phase method. The peptides were purified by gel filtration or ion-exchange chromatography on Sephadex SP-C-25. Both peptides induced a cellular and humoral immune response in rabbits. The results showed that fragment 14-22 of pre-S2 region contains one of the antigenic determinants.

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Kawamoto, R. M., J. P. Brunschwig, K. C. Kim et A. H. Caswell. « Isolation, characterization, and localization of the spanning protein from skeletal muscle triads. » Journal of Cell Biology 103, n^o 4 (1 octobre 1986) : 1405–14. http://dx.doi.org/10.1083/jcb.103.4.1405.

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A monoclonal antibody has been developed against the putative junctional protein or spanning protein (SP) from skeletal muscle triads. By immuno-affinity chromatography, we have purified this protein. The native protein has a molecular mass of 630-800 kD, as determined by gel filtration and rate zonal centrifugation. Within the limits of the methods used, the basic unit of the SP appears to be a dimer. In electron micrographs, it is shown to exhibit a circular profile with a diameter of approximately 100 A. In thin section analysis, the protein is frequently observed as parallel tracks of electron-dense particles bordering a translucent core. We suggest that the basic unit of the junctional structure is a dimer of 300-kD subunits and that four such entities constitute the intact SP. The purified protein has been used to develop polyclonal antibodies. By immunoelectron microscopy using immunogold probes, the SP has been localized to the junctional gap of the triad. By attaching the SP to an affinity resin, three proteins have been identified as forming associations with the SP. The Mrs of the proteins are 150, 62, and 38 kD; the 62-kD protein is calsequestrin.

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Seri, I., et A. Aperia. « Contribution of dopamine 2 receptors to dopamine-induced increase in glomerular filtration rate ». American Journal of Physiology-Renal Physiology 254, n^o 2 (1 février 1988) : F196—F201. http://dx.doi.org/10.1152/ajprenal.1988.254.2.f196.

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The effects of the interaction of dopamine (DA) and the DA2 receptors on glomerular filtration rate (GFR) has been studied by means of micropuncture technique in adult greater than or equal to 60-day-old and young 24-day-old rats. Most of the studies were performed in rats with intact adrenergic nervous systems to allow for evaluation of the presynaptic DA2 receptors. In adult and young rats, DA and LY-171555 (LY), a selective DA2 receptor agonist, induced prompt and significant increases in the single nephron (SN) GFR. Further studies were performed only in adult rats. The LY-induced increase in SNGFR was completely abolished during DA2 receptor blockade with S-sulpiride (S-SP), while the DA-induced increase in SNGFR was attenuated but still significant during S-SP treatment. Both DA and LY significantly increased the glomerular ultra-filtration pressure (PUFAA). In rats with ganglionic blockade, the LY-induced increase of SNGFR was attenuated but still significant, whereas the DA-induced increase was less affected. The results imply that DA significantly increases GFR by interacting with the DA2 as well as with the DA1 receptors. Interaction between DA and the DA2 receptors increases PUFAA. The results do not rule out the existence of both pre- and postsynaptic renal DA2 receptors.

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Lin, Wên Hsiung. « An infinite family in ${}\sb 2\pi\sp {\rm s}\sb *$ at Adams filtration seven ». Transactions of the American Mathematical Society 328, n^o 1 (1 janvier 1991) : 133–49. http://dx.doi.org/10.1090/s0002-9947-1991-1044962-x.

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Davis, Michael J., Megan M. Lane, Ann M. Davis, David Durtschi, David C. Zawieja, Mariappan Muthuchamy et Anatoliy A. Gashev. « Modulation of lymphatic muscle contractility by the neuropeptide substance P ». American Journal of Physiology-Heart and Circulatory Physiology 295, n^o 2 (août 2008) : H587—H597. http://dx.doi.org/10.1152/ajpheart.01029.2007.

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Substance P (SP) is a neuropeptide associated with sensory innervation of lymphoid tissue and a suspected modulator of lymphatic function in inflammation. Only a few studies have examined the effects of SP on lymphatic contraction, and it is not clear to what extent SP acts directly on the lymphatic muscle and/or endothelium or indirectly through changes in intraluminal filling pressure secondary to increases in capillary permeability/filtration. We tested the effects of SP on the spontaneous contractions of rat isolated mesenteric lymphatic vessels under isometric and isobaric conditions, hypothesizing that low concentrations would stimulate lymphatic pumping by enhancing lymphatic muscle contraction in a manner complementary to the effect of increased preload. Under isometric conditions, SP (10 nM) dramatically enhanced lymphatic chronotropy and inotropy. Unlike guinea pig lymphatics, SP actions were not blocked by cyclooxygenase or PLA2inhibition. In the absence of SP, ramp increases in isometric preload resulted in ×∼1.6 increases in contraction amplitude (Amp) and ×∼1.7 increases in frequency (Freq). SP increased Freq by ×∼2.4, Amp by ×∼1.9, and the Amp-Freq product (AFP) by ×∼3.5. Under isobaric conditions, the pressure elevation from 0.5 to 10 cmH2O in the absence of SP decreased Amp by ×∼0.6 and increased Freq by ×∼1.8. SP caused a modest increase in Amp, a robust increase in Freq at all pressures, and shifted the AFP-pressure relationship upward and leftward. Therefore, SP has substantial positive inotropic and chronotropic effects on rat lymphatic muscle, improving pump efficiency independent of the effects of preload and broadening of the working range of the lymphatic pump.

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Am-In, Somjit, Savitree Limtong, Wichien Yongmanitchai et Sasitorn Jindamorakot. « Candida andamanensis sp. nov., Candida laemsonensis sp. nov. and Candida ranongensis sp. nov., anamorphic yeast species isolated from estuarine waters in a Thai mangrove forest ». International Journal of Systematic and Evolutionary Microbiology 61, n^o 2 (1 février 2011) : 454–61. http://dx.doi.org/10.1099/ijs.0.022038-0.

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Five strains (RV5T, RV140, R31T, RS17 and RS28T) representing three novel anamorphic ascomycetous yeast species were isolated by membrane filtration from estuarine waters collected from a mangrove forest in Laem Son National Park, Ranong Province, Thailand, on different occasions. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, sequence analysis of the D1/D2 domain of the large-subunit rRNA gene and the internal transcribed spacer region and phylogenetic analysis, three strains were found to represent two novel Candida species. Two strains (RV5T and RV140) represented a single novel species, for which the name Candida laemsonensis sp. nov. is proposed. The type strain is RV5T (=BCC 35154T =NBRC 105873T =CBS 11419T). Strain R31T was assigned to a novel species that was named Candida andamanensis sp. nov. (type strain R31T =BCC 25965T =NBRC 103862T =CBS 10859T). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, sequence analysis of the D1/D2 domain of the large-subunit rRNA gene and phylogenetic analysis, strains RS17 and RS28T represented another novel species of Candida, for which the name Candida ranongensis sp. nov. is proposed. The type strain is RS28T (=BCC 25964T =NBRC 103861T =CBS 10861T).

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Driscoll, Julia, Irene K. Yan et Tushar Patel. « Development of a Lyophilized Off-the-Shelf Mesenchymal Stem Cell-Derived Acellular Therapeutic ». Pharmaceutics 14, n^o 4 (13 avril 2022) : 849. http://dx.doi.org/10.3390/pharmaceutics14040849.

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The therapeutic activities elicited by mesenchymal stem cells (MSC) are in part mediated through paracrine action by the release of extracellular vesicles (EV) and secreted proteins. Collectively, these MSC-derived factors, referred to as the secretome product (SP), are intrinsically therapeutic and represent an attractive alternative to cell-based therapies. Herein, we developed a lyopreservation protocol to extend the shelf-life of the MSC-SP without compromising the structural or functional integrity of the vesicular components. The SP isolated from normoxia- and anoxia-exposed MSC elicited protective effects in an in vitro model of oxidative injury and the bioactivity was retained in the lyophilized samples. Three separate formulations of MSC-SP were isolated by tangential flow filtration using sucrose, trehalose, and mannitol as lyoprotectant agents. The MSC-SPs were lyophilized using a manifold protocol and the structural and functional integrity were assessed. The trehalose formulation of SP exhibited the highest EV and protein recovery after manifold-based lyophilization. To facilitate development as a therapeutic, a shelf lyophilization protocol was developed which markedly enhanced the recovery of EV and proteins. In conclusion, lyophilization represents an efficient method to preserve the structural and functional integrity of the MSC-SP and can be used to develop an off-the-shelf therapeutic.

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Marella, Chenchaiah, Venkateswarlu Sunkesula, Ahmed R. A. Hammam, Anil Kommineni et Lloyd E. Metzger. « Optimization of Spiral-Wound Microfiltration Process Parameters for the Production of Micellar Casein Concentrate ». Membranes 11, n^o 9 (26 août 2021) : 656. http://dx.doi.org/10.3390/membranes11090656.

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A systematic selection of different transmembrane pressures (TMP) and levels of diafiltration (DF) was studied to optimize these critical process parameters during the manufacturing of micellar casein concentrate (MCC) using spiral-wound polymeric membrane filtration. Three TMPs (34.5, 62.1, and 103.4 kPa) and four DF levels (0, 70, 100, and 150%) were applied in the study. The effect of the TMP and DF level on flux rates, serum protein (SP) removal, the casein-to-total-protein ratio, the casein-to-true-protein ratio, and the rejection of casein and SP were evaluated. At all transmembrane pressures, the overall flux increased with increases in the DF level. The impact of DF on the overall flux was more pronounced at lower pressures than at higher pressures. With controlled DF, the instantaneous flux was maintained within 80% of the initial flux for the entire process run. The combination of 34.5 kPa and a DF level of 150% resulted in 81.45% SP removal, and a casein-to-true-protein ratio of 0.96. SP removal data from the lab-scale experiments were fitted into a mathematical model using DF levels and the square of TMPs as factors. The model developed in this study could predict SP removal within 90–95% of actual SP removal achieved from the pilot plant experiments.

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Zou, Zhike, Longcang Shu, Xing Min et Esther Chifuniro Mabedi. « Physical Experiment and Modeling of the Transport and Deposition of Polydisperse Particles in Stormwater : Effects of a Depth-Dependent Initial Filter Coefficient ». Water 11, n^o 9 (11 septembre 2019) : 1885. http://dx.doi.org/10.3390/w11091885.

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The artificial recharge of stormwater is an effective approach for replenishing aquifer and reduce urban waterlogging, but prone to clogging by suspended particles (SP) that are highly heterogeneously sized. In this paper, the transport and deposition of SP in a sand column were investigated under a constant flow condition, for five stormwater concentrations. A depth-dependent initial filter coefficient is incorporated into the conventional filtration model. This modified model considers the heterogeneity of the particle population by lumping the capture of heterogeneous SP into a capture probability. The good agreement between the results of the modified model and the experimental results of measured outlet concentration and average specific deposit validated the modified model. The experiment data and the simulation results both indicate that the highly hyper-exponential retention profiles are caused by non-uniform deposition of heterogeneous SP; and, the conventional model was found to homogenize the spatial distribution of SP retention and overestimate retention of the porous medium. Local and overall permeability reductions were assessed by an empirical relationship and the Kozeny-Carman model, respectively. It is shown that consideration of polydisperse suspended particles is of primary importance. This study highlights the effects of polydisperse particles on SP deposition in a saturated porous medium.

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NUNES, D. S., H. T. GONZAGA, V. S. RIBEIRO, J. P. CUNHA-JÚNIOR et J. M. COSTA-CRUZ. « Usefulness of gel filtration fraction as potential biomarker for neurocysticercosis in serum : towards a new diagnostic tool ». Parasitology 144, n^o 4 (17 octobre 2016) : 426–35. http://dx.doi.org/10.1017/s0031182016001839.

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SUMMARYThere is an increasing interest in improving neurocysticercosis (NCC) diagnosis through the search of new and alternative antigenic sources, as those obtained from heterologous antigens. The aim of this study was to obtain potential biomarkers for NCC diagnosis after gel filtration chromatography [gel filtration fraction (GFF)] from the total saline extract (SE) from Taenia saginata metacestodes, followed by protein identification and application in immunodiagnostic. SE and GFF proteic profiles were characterized in gel electrophoresis, and diagnostic performance was verified by testing 160 serum samples through enzyme-linked immunosorbent assay and immunoblotting. Sensitivity (Se), specificity (Sp) and other diagnostic parameters were calculated. Polypeptides of interest in the diagnosis of human NCC present at GFF were analysed by mass spectrometry (MS) and B-cell epitopes were predicted. GFF had the best diagnostic parameters: Se 93·3%; Sp 93%; AUC 0·990; LR+ = 13·42 and LR− = 0·07, and proved to be useful reacting with serum samples in immunoblotting. Proteic profile ranged from 64 to 68 kDa and enolase and calcium binding protein calreticulin precursor were identified after MS. The enolase and calcium-binding protein calreticulin precursor showed 18 and 10 predicted B-cell epitopes, respectively. In conclusion we identified important markers in the GFF with high efficiency to diagnose NCC.

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Murata, Y., Y. Kuroki et T. Akino. « Role of the C-terminal domain of pulmonary surfactant protein A in binding to alveolar type II cells and regulation of phospholipid secretion ». Biochemical Journal 291, n^o 1 (1 avril 1993) : 71–76. http://dx.doi.org/10.1042/bj2910071.

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Surfactant protein A (SP-A), with a reduced denatured molecular mass of 26-38 kDa, is characterized by a collagen-like sequence in the N-terminal half of the protein. This protein forms an oligomeric structure which is dependent upon this collagenous domain. SP-A has been demonstrated to function as an inhibitor of phospholipid secretion by primary cultures of alveolar type II cells via a cell surface receptor for the protein. However, the receptor-binding domain of SP-A has not been identified. The purpose of the present study was to investigate the role of the C-terminal domain of SP-A in binding to type II cells and regulation of phospholipid secretion. A monoclonal antibody to human SP-A, whose epitope was localized at the C-terminal domain of the protein, abolished the inhibitory activity of human SP-A on lipid secretion by type II cells, and attenuated the ability of human SP-A to compete with 125I-(rat SP-A) for receptor binding. SP-A was then digested with collagenase and the collagenase-resistant fragment (CRF), which is the C-terminal domain of SP-A (thus lacking the N-terminal domain), was isolated. Gel filtration chromatography revealed that CRF exists as a monomer in solution containing Ca2+. CRF had the ability to inhibit phospholipid secretion, although at a higher concentration than for SP-A, and was also able to compete with 125I-(rat SP-A) for binding to type II cells. A direct binding study showed that CRF bound to type II cells in a concentration-dependent manner. The present study demonstrates that the non-collagenous, C-terminal, domain of SP-A is responsible for the protein's inhibitory effect on lipid secretion and its binding to type II cells.

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Eades, Andrew, et W. J. Brignall. « Counter-current dissolved air flotation/filtration ». Water Science and Technology 31, n^o 3-4 (1 février 1995) : 173–78. http://dx.doi.org/10.2166/wst.1995.0527.

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Thames Water Utilities has developed and patented a Counter-current dissolved air flotation/filtration (COCO-DAFF) process as a compact water treatment system designed to remove particulate material from traditional water sources. In particular it has been developed to overcome operational problems with primary filters caused by seasonal blooms of filter blocking algae such as Melosira sp., Aphanizomenon sp. andAnabaena sp. The process can be run without flotation during periods when algae are not a problem, giving operational cost savings. This process differs from co-current dissolved air flotation in that the recycle water is introduced after the inlet structure, but above the filter media. This generates an even depth bubble blanket in the flotation tank through which all the flocculated water must pass. The advantages are that in moving the recycle inlet away from the flocculated water inlet the potential for floc damage by the recycle is eliminated. Also since the entire sludge blanket is supported by a deep, even, bubble blanket, on de-sludging any fall-out of sludge that occurs near the de-sludging weirs will have to go back down through the process, leading to subsequent re-floating, and a reduced potential for spiking of the floated turbidity. Process validation experiments have been carried out on a 1.4 Ml/d pilot plant based at the Kempton Advanced Water Treatment Centre, London. These tests have identified a required flocculation time of 15 minutes prior to counter-current flotation, and insensitivity to the depth of the air injection below top water level. Dissolved air distribution is achieved using a special high volume flow rate DAF nozzle designed to lower the number of nozzles required per unit area, and to maximise the spread of the bubble cloud for optimum bubble/particle contact. Computational fluid dynamics (CFD) has been used in the scale-up of the pilot plant experience into the first full scale of this design plant to be built, by PWT Projects, at the 200 Ml/d Walton AWTW, for Thames Water Utilities.

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Bautista-Anguiano, Joshua, et Carlos Torres-Verdín. « Inversion-based interpretation of borehole spontaneous potential measurements for accurate estimation of water resistivity in the presence of shoulder-bed and mud-filtrate invasion effects ». GEOPHYSICS 87, n^o 2 (15 février 2022) : D47—D65. http://dx.doi.org/10.1190/geo2021-0092.1.

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Electrical resistivity of formation water is a fundamental property used to quantify in situ water quality for human consumption or for assessment of hydrocarbon pore volume. Resistivity interpretation methods commonly used to quantify the electrical resistivity of formation water invoke rock porosity and fitting parameters that require additional and independent core measurements. Alternatively, the spontaneous potential (SP) log can be used to calculate water resistivity without knowledge of rock porosity in wells drilled with water-based mud. In combination with resistivity and gamma-ray logs, SP logs can be used to estimate water quality, apparent volumetric concentration of shale, and for qualitative assessments of permeability. However, SP logs often exhibit shoulder-bed and mud-filtration effects; these effects need to be mitigated before using SP logs for calculation of water resistivity. We have developed a new inversion-based method to simultaneously mitigate shoulder-bed and mud-filtrate invasion effects present in SP logs via fast numerical simulations based on Green functions. The interpretation method was implemented on SP logs acquired across aquifers with various degrees of complexity using noisy synthetic and field measurements to estimate equivalent NaCl concentration, radius of mud-filtrate invasion, and sodium macroscopic transport number. Interpretation results compared well to those obtained from resistivity and nuclear logs, provided estimates of uncertainty, and could incorporate a priori knowledge of aquifer petrophysical properties in the estimation.

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Lai, Yih-Loong, Szu-Jung Chu, Ming-Chieh Ma et Chau-Fong Chen. « Temporal increase in the reactivity of pulmonary vasculature to substance P in chronically hypoxic rats ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 282, n^o 3 (1 mars 2002) : R858—R864. http://dx.doi.org/10.1152/ajpregu.00429.2001.

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We previously demonstrated that the pulmonary vascular response to substance P (SP) increased in chronically hypoxic rats. This study explored the temporal increase in reactivity of the pulmonary vascular response to SP and its underlying mechanisms. First, young female Wistar rats were exposed to sea level (SL) or simulated high altitude (HA) for 15 h/day for 3 days, 1 wk, 2 wk, and 4 wk. Lungs were isolated and perfused with 4% bovine serum albumin in Krebs-Henseleit buffer solution. SP (1.5 × 10−4 M) induced significant increases in pulmonary arterial pressure (Ppa), venous pressure (Pv), capillary pressure (Pc), arterial resistance (Ra), and filtration coefficient ( K fc) in SL lungs. Increases in Ppaand Ra were significantly augmented in HA lungs, with a temporal increase trend peaking at 2 wk of HA exposure. The selective neurokinin (NK) type 1 (NK1) receptor antagonist SR-14033 significantly attenuated SP-induced increases in Ppa, Pv, Pc, Ra, and K fc in SL lungs. In lungs exposed to HA for 2 wk, SR-14033 suppressed the effect of SP on Ppa. Also, chronic hypoxia induced significant increases in NK1receptors and NK1 receptor mRNA, with a temporal trend. We conclude that chronic hypoxia temporally augments SP-induced vascular responses, which are closely associated with increases in NK1 receptors and gene expression.

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Lung, Wei Qing Chloe, Han-Yang Yeh, Sheng-Jie Yang, Chin-Yi Huang, Fan-Hua Nan et Meng-Chou Lee. « Delayed Signs of UV-C Damage to Chlorella sp. Observed through Fluorescent Staining ». Diversity 14, n^o 5 (7 mai 2022) : 376. http://dx.doi.org/10.3390/d14050376.

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Ultraviolet (UV-C) irradiation is the most important part of water filtration, which has no side effects on the environment and has been used in water purification systems in the aquaculture and transistor industries. In this research, the effect of UV-C on Chlorella sp. was investigated. Chlorella sp. was irradiated 0, 1, 2 or 3 times at a fixed flow rate of 6.5 L min−1 and the effects of UV-C LED on the apoptosis rate and death rate of Chlorella sp. were analyzed by flow cytometry after staining cells with the nucleic acid dye SYTOX Green and the membrane-associated protein stain Annexin V-PE Reagent. As a result of UV-C irradiation, the Chlorella sp. cells underwent phosphatidylserine (PS) ectropion and plasma membrane damage, which resulted in death. The effect of UV-C was proportional to the number of times of irradiation. Three doses of UV-C LED irradiation resulted in a 91.76 ± 3.33% death rate, as observed through SYTOX Green staining, with no rebound within 72 h. This research is the first report to observe that delayed cellular apoptosis occurred in Chlorella sp., and we expect that our study can be used as a standard reference for future industrial applications.

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Crossman, D. C., M. R. Dashwood, G. W. Taylor, R. Wellings et R. W. Fuller. « Sodium cromoglycate : evidence of tachykinin antagonist activity in the human skin ». Journal of Applied Physiology 75, n^o 1 (1 juillet 1993) : 167–72. http://dx.doi.org/10.1152/jappl.1993.75.1.167.

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The mechanism of action of the antiasthmatic drug sodium cromoglycate (SCG) is unclear. One possibility is that SCG antagonizes the effects of the tachykinin substance P (SP), an agent known to cause airway edema. However, when SP is inhaled by humans, it has no demonstrable effect on airway function; therefore, the possibility that SCG prevents SP-induced changes in microvascular permeability was examined in human skin in vivo where potent edema-producing effects are seen. SCG (5–500 nmol) caused significant (P < 0.05) dose-dependent inhibition of SP-induced edema (wheal) formation when coadministered by intradermal injection. There was no effect on the nonreceptor-mediated flare response. SCG also significantly (P < 0.05) inhibited the wheal response to the related tachykinin neurokinin B but had no inhibitory effect on the cutaneous responses to histamine and prostaglandin E2. In addition, SCG (0.1–10 mM) caused dose-dependent inhibition of binding of SP labeled with 125I-labeled Bolton-Hunter to a number of tissues known to contain SP binding sites, as assessed by autoradiography. These concentrations were equivalent to the final concentrations of SCG found to inhibit the wheal response in the skin. The possibility that SCG interacted with SP was investigated both by gel filtration and high-performance liquid chromatography. No strong interaction was demonstrated with an 8,000 M excess of SCG under both hydrophobic and hydrophilic conditions. These results raise the possibility that SCG may have tachykinin antagonist properties.

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Ismail, Insyirah, Kiki Adi Kurnia, Shafirah Samsuri, Muhammad Roil Bilad, Lisendra Marbelia, Noor Maizura Ismail, Asim Laeeq Khan, Arief Budiman et Susilawati Susilawati. « Energy efficient harvesting of Spirulina sp. from the growth medium using a tilted panel membrane filtration ». Bioresource Technology Reports 15 (septembre 2021) : 100697. http://dx.doi.org/10.1016/j.biteb.2021.100697.

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Zou, Zhike, Longcang Shu, Xing Min et Esther Chifuniro Mabedi. « Clogging of Infiltration Basin and Its Impact on Suspended Particles Transport in Unconfined Sand Aquifer : Insights from a Laboratory Study ». Water 11, n^o 5 (24 mai 2019) : 1083. http://dx.doi.org/10.3390/w11051083.

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A laboratory study was undertaken to investigate the physical clogging of a sand medium by injecting suspended particles (SP), with diameters ranging from 0.03 to 63.41 μm, into an infiltration basin, which was installed in a sand tank under the condition of constant head. The hydraulic conductivity (K) of the saturated porous medium was found to have decreased by 27% because of re-arrangement over the seven days of self-filtration. A clogging layer was observed on the infiltration basin bottom, probably due to straining over the stormwater infiltration stage. Particle-size analyses also indicate that retention of bigger SP led to faster straining of smaller SP, despite the small fraction of bigger SP. The clogging layer weakened the hydraulic connection between the water level in the basin and the water table of the unconfined aquifer until nearly no water could infiltrate into the aquifer. The deposition of finer SP that entered into the aquifer are governed by the hydrodynamic forces. These finer SP caused non-uniform permeability reduction of the porous medium, with an estimated 35% of permeability reduction occurring beneath the infiltration basin. However, the reduction appears to be reversible, as the fine SP deposited on the pore surfaces of the porous medium can be released or detached by the continuous horizontal hydraulic gradient. Extended tailing of the outlet breakthrough curve (BTC) also strongly supported the detachment of SP. This study focused on the effects of particles’ polydispersity and hydrodynamic forces on the hydraulic characteristics of the porous medium.

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Cai, Guang-Zuan, Gail L. Griffin, Robert M. Senior, William J. Longmore et Michael A. Moxley. « Recombinant SP-D carbohydrate recognition domain is a chemoattractant for human neutrophils ». American Journal of Physiology-Lung Cellular and Molecular Physiology 276, n^o 1 (1 janvier 1999) : L131—L136. http://dx.doi.org/10.1152/ajplung.1999.276.1.l131.

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Human pulmonary surfactant protein D (SP-D) is a collagenous C-type lectin with high binding specificity to α-d-glucosyl residues. It is composed of four regions: a short NH2-terminal noncollagen sequence, a collagenous domain, a short linking domain (“neck” region), and a COOH-terminal carbohydrate recognition domain (CRD). Previous studies demonstrated that SP-D is chemotactic for inflammatory cells. To test which domain of SP-D might play a role in this function, a mutant that contains only neck and CRD regions was expressed in Escherichia coli and purified by affinity chromatography on maltosyl-agarose. A 17-kDa recombinant SP-D CRD was identified by two antibodies (antisynthetic SP-D COOH-terminal and neck region peptides) but not by synthetic SP-D NH2-terminal peptide antibody. The recombinant SP-D CRD was confirmed by amino acid sequencing. Gel-filtration analysis found that 84% of CRD was trimeric and the rest was monomeric. Analysis of the chemotactic properties of the trimeric CRD demonstrated that the CRD was chemotactic for neutrophils (polymorphonuclear leukocytes), with peak activity at 10−10 M equal to the positive control [formyl-Met-Leu-Phe (fMLP) at 10−8 M]. The chemotactic activity was abolished by 20 mM maltose, which did not suppress the chemotactic response to fMLP. The peak chemotactic activity of the CRD is comparable to the activity of native SP-D, although a higher concentration is required for peak activity (10−10 vs. 10−11 M). The chemotactic response to CRD was largely prevented by preincubation of polymorphonuclear leukocytes with SP-D, and the response to SP-D was prevented by preincubation with CRD. These preincubations did not affect chemotaxis to fMLP. These results suggest that trimeric CRD accounts for the chemotactic activity of SP-D.

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IWATA, Y., et M. SUZUKI. « PIXE APPLICATION FOR MEASUREMENT OF BIOACCUMULATION OF LEAD BY MARINE MICRO-ALGAE ». International Journal of PIXE 10, n^o 01n02 (janvier 2000) : 27–35. http://dx.doi.org/10.1142/s0129083500000055.

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Marine micro-algae (Nannochloropsis sp., and Phaeodactylum sp.,) were obtained from the Pacific Ocean of Iwate Pref., Japan and purely cultured in nutritive seawater as a culture solution. The culture size for algae was 10 - 250 ml and every apparatus was small and of low cost. Marine micro-algae were given in different culture solutions including Pb 2+ from 0.01 to 1.0 mg /l. The algae in 5 ml of the culture solution were collected on a polycarbonate filter (pore size : 1.0 μm) by suction filtration. The algae on the filter were subjected to PIXE analysis. Concentrations of Na , Mg , Si , P , S , Cl , K , Ca , Cr , Mn , Fe , Cu , Zn , Sr and Pb were simultaneously determined. PIXE can do multi-element analysis for a sample of below 1 mg. The quantity of lead in marine micro-algae increases in proportion to the Pb 2+ concentration in the culture solution. The concentration factor (wet weight base) for lead is given as 200 ± 20 ml / g for Nannochloropsis sp. and 1900 ± 400 ml / g for Phaeodactylum sp.. It is shown that PIXE is a powerful tool for the measurement of the bioaccumulation of trace elements.

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Anchang-Kimbi, Judith K., Dillys Mansoh Elad, Gemain Taiwe Sotoing et Eric Akum Achidi. « Coinfection withSchistosoma haematobiumandPlasmodium falciparumand Anaemia Severity among Pregnant Women in Munyenge, Mount Cameroon Area : A Cross-Sectional Study ». Journal of Parasitology Research 2017 (2017) : 1–12. http://dx.doi.org/10.1155/2017/6173465.

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Background. Malaria and urogenital schistosomiasis are coendemic in Mount Cameroon Area. This study investigated the prevalence ofS. haematobium,P. falciparum,and coinfections and their effect on anaemia in pregnancy.Methods. Pregnant women reporting for antenatal care (ANC) clinic visit in Munyenge were enrolled.S. haematobiumandP. falciparuminfections were determined by urine filtration and microscopy, respectively. Haemoglobin (Hb) levels were measured using haemoglobinometer. Of 250 women, 46.8%, 39.2%, and 15.2% hadS. haematobium,P. falciparum,and coinfections, respectively. Schistosomes infection was higher in younger women (≤25 years) and those who bathe in and had domestic contact with stream compared with older age (>25 years) women and those who had only domestic contact with stream. Lower infection rate was associated with less water contact (≤2 times/day) compared with more water contact (>2 times/day). Compared with no sulphadoxine-pyrimethamine (SP) usage, malaria parasitaemia was less among women who used SP. Stream usage increased risk of coinfection while less water contact and SP usage decreased its risk. All coinfected cases were anaemic and coinfection accounted for 93.8% of severe anaemia.Conclusion. Coinfection contributes to anaemia severity. Less water contact and SP usage will reduce coinfection in pregnancy in Munyenge.

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Rhea, Nicholas, John Groppo et Czarena Crofcheck. « Evaluation of Flocculation, Sedimentation, and Filtration for Dewatering of Scenedesmus Algae ». Transactions of the ASABE 60, n^o 4 (2017) : 1359–67. http://dx.doi.org/10.13031/trans.12116.

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Abstract. Algae can be used as a feedstock for agricultural fertilizers, livestock and poultry feeds, anaerobic digestion, and biofuel production. For each end product, the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy needs to be adaptable to varying levels of water removal. Flocculation, sedimentation, and filtration were evaluated as possible strategies for thickening and dewatering of algae. The goal of this study was to validate that algae cells treated by such means could be processed by vacuum belt filters and to determine the conditions under which the solids content could be increased to 5 to 25 wt%. The flocculation and sedimentation studies focused on conditions needed to thicken algae from a culture concentration range of 0.4 to 1 g L-1 to an end-product concentration range of 15 to 50 g L-1. Sedimentation rates of were measured with varying flocculant dosages (0 to 25 ppm) for various flocculants. The highest level of compaction was achieved with a synthetic cationic polymeric flocculant with higher molecular weight at a dosage of 15 ppm, which provided 16.3 mL of compacted solids (3.3 wt% solids). Subsequently, solids were successfully separated as a cake via gravity and vacuum filtration. The filtration studies focused on the conditions needed to filter flocculated algae slurry from a concentration range of 15 to 50 g L-1 to a product at a concentration range of 50 to 250 g L-1. Filtration rates of were measured on algae slurry treated with 10 to 15 ppm of a synthetic cationic polymeric flocculant. Processing parameters such as cake formation time, filtration rate, and mass throughput were evaluated against variables such as cake thickness, feed concentration, and processing time. Keywords: Algae, Dewatering, Filtration, Flocculation, Scenedesmus sp., Sedimentation, Thickening.

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Iwabuchi, Tokuro, et Shigeaki Harayama. « Biochemical and Genetic Characterization oftrans-2′-Carboxybenzalpyruvate Hydratase-Aldolase from a Phenanthrene-Degrading Nocardioides Strain ». Journal of Bacteriology 180, n^o 4 (15 février 1998) : 945–49. http://dx.doi.org/10.1128/jb.180.4.945-949.1998.

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ABSTRACT trans-2′-Carboxybenzalpyruvate hydratase-aldolase was purified from a phenanthrene-degrading bacterium,Nocardioides sp. strain KP7, and characterized. The purified enzyme was found to have molecular masses of 38 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 113 kDa by gel filtration chromatography. Thus, the homotrimer of the 38-kDa subunit constituted an active enzyme. The Km andkcat values of this enzyme fortrans-2′-carboxybenzalpyruvate were 50 μM and 13 s−1, respectively.trans-2′-Carboxybenzalpyruvate was transformed to 2-carboxybenzaldehyde and pyruvate by the action of this enzyme. The structural gene for this enzyme was cloned and sequenced; the length of this gene was 996 bp. The deduced amino acid sequence of this enzyme exhibited homology to those oftrans-2′-hydroxybenzalpyruvate hydratase-aldolases fromPseudomonas putida PpG7 and Pseudomonas sp. strain C18.

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Bernhard, Wolfgang, Andreas Gebert, Gertrud Vieten, Gunnar A. Rau, Jens M. Hohlfeld, Anthony D. Postle et Joachim Freihorst. « Pulmonary surfactant in birds : coping with surface tension in a tubular lung ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, n^o 1 (1 juillet 2001) : R327—R337. http://dx.doi.org/10.1152/ajpregu.2001.281.1.r327.

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As birds have tubular lungs that do not contain alveoli, avian surfactant predominantly functions to maintain airflow in tubes rather than to prevent alveolar collapse. Consequently, we have evaluated structural, biochemical, and functional parameters of avian surfactant as a model for airway surfactant in the mammalian lung. Surfactant was isolated from duck, chicken, and pig lung lavage fluid by differential centrifugation. Electron microscopy revealed a uniform surfactant layer within the air capillaries of the bird lungs, and there was no tubular myelin in purified avian surfactants. Phosphatidylcholine molecular species of the various surfactants were measured by HPLC. Compared with pig surfactant, both bird surfactants were enriched in dipalmitoylphosphatidylcholine, the principle surface tension-lowering agent in surfactant, and depleted in palmitoylmyristoylphosphatidylcholine, the other disaturated phosphatidylcholine of mammalian surfactant. Surfactant protein (SP)-A was determined by immunoblot analysis, and SP-B and SP-C were determined by gel-filtration HPLC. Neither SP-A nor SP-C was detectable in either bird surfactant, but both preparations of surfactant contained SP-B. Surface tension function was determined using both the pulsating bubble surfactometer (PBS) and capillary surfactometer (CS). Under dynamic cycling conditions, where pig surfactant readily reached minimal surface tension values below 5 mN/m, neither avian surfactant reached values below 15 mN/m within 10 pulsations. However, maximal surface tension of avian surfactant was lower than that of porcine surfactant, and all surfactants were equally efficient in the CS. We conclude that a surfactant composed primarily of dipalmitoylphosphatidylcholine and SP-B is adequate to maintain patency of the air capillaries of the bird lung.

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Wang, Jiaojiao, Pingchuan Yuan, Wenzhi Zhang, Chunyan Liu, Kaoshan Chen, Guodong Wang et Taili Shao. « Separation, Purification, Structural Characterization, and Anticancer Activity of a Novel Exopolysaccharide from Mucor sp. » Molecules 27, n^o 7 (23 mars 2022) : 2071. http://dx.doi.org/10.3390/molecules27072071.

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Mucor sp. has a wide range of applications in the food fermentation industry. In this study, a novel exopolysaccharide, labeled MSEPS, was separated from Mucor sp. fermentation broth through ethanol precipitation and was purified by ion-exchange chromatography, as well as gel filtration column chromatography. MSEPS was composed mostly of mannose, galactose, fucose, arabinose, and glucose with a molar ratio of 0.466:0.169:0.139:0.126:0.015 and had a molecular weight of 7.78 × 104 Da. The analysis of methylation and nuclear magnetic resonance results indicated that MSEPS mainly consisted of a backbone of →3,6)-α-d-Manp-(1→3,6)-β-d-Galp-(1→, with substitution at O-3 of →6)-α-d-Manp-(1→ and →6)-β-d-Galp-(1→ by terminal α-l-Araf residues. MTT assays showed that MSEPS was nontoxic in normal cells (HK-2 cells) and inhibited the proliferation of carcinoma cells (SGC-7901 cells). Additionally, morphological analysis and flow cytometry experiments indicated that MSEPS promoted SGC-7901 cell death via apoptosis. Therefore, MSEPS from Mucor sp. can be developed as a potential antitumor agent.

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Lushchaeva, Inna V., Yuri N. Morgalev et Sergey V. Loiko. « Influence of Nickel Nanoparticles on Biological Activity of Humus Layer of Subboreal Forest ». Nano Hybrids and Composites 13 (janvier 2017) : 108–14. http://dx.doi.org/10.4028/www.scientific.net/nhc.13.108.

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For the first time studied the influence of nickel nanoparticles (Ni NPs) on the integrated index of biological activity of humus soil horizons in subboreal forest after treating with a 5.0 mg/l dispersion of nanoparticles. Adding nickel nanoparticle dispersion into the soil was carried out in filtration columns. Treatment of humus soils with Ni NPs has been established to decrease total microbial number to 50 % - 65 % in CFU, stimulate nitrification in all soil samples and a suppression of nitrogen fixation in loam soils Model tests on agar media with pure cultures of Pseudomonas fluorescens and Candida sp. showed varied sensitivity of different systematic groups to nickel nanoparticles. No positive CFU decrease of Pseudomonas fluorescens was found. However, in respect to certain concentrations of Ni NPs in an experiment with Candida sp., a marked decrease of CFU was observed.

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Kim, Dong-Ho, Changkyoo Choi, Chulmin Lee, Rusnang Syamsul Adha, Thanh-Tin Nguyen, Sang-Jun Ahn, Hee-Jong Son et In S. Kim. « An Improved Configuration of Vertical-Flow Mesh Tube Filters for Seawater Pretreatment : Performance, Cleaning, and Energy Consumption ». Water 12, n^o 10 (10 octobre 2020) : 2804. http://dx.doi.org/10.3390/w12102804.

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Roughing filters are types of porous media filter used in pretreatment systems where the raw water contains a large amount of suspended particles (SPs) and organic matter. Mesh tube filtration (MTF) media are roughing-filter media composed of low-density polyethylene used for SP removal during wastewater treatment. In this study, we present an improved MTF design—a porous filter bed (PFB), which exhibits superior SP removal performance compared to conventional MTF media. We then compare the applicability of MTF and PFB to both the primary pretreatment process for seawater desalination and the water reuse process. In bench-scale SP removal experiments, PFB shows removal rates of 46.7%, 68.0%, 67.6%, and 68.4% at hydraulic retention times of 15, 20, 30, and 60 min, respectively, which are better than those of MTF. The specific energy consumption (SEC) of batch dissolved air flotation (DAF) was known to range from 0.035 to 0.047 kWh/m3, whereas the SEC calculated for pilot-scale MTF and PFB is 0.027 kWh/m3 and minimum energy for influent supply, respectively. This suggests that PFB can compete with DAF as a primary pretreatment process. MTF predominantly removes SPs by sedimentation, whereas SP removal in PFB typically occurs via deposition of SPs on the mesh tube media.

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Essmaa Hussein Gutef. « Cytotoxic activity of arginine deiminase purified from Lactobacillus sp ». World Journal of Advanced Research and Reviews 16, n^o 1 (30 octobre 2022) : 647–52. http://dx.doi.org/10.30574/wjarr.2022.16.1.1094.

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The goal of this research was to characterize ADI isolated from Lactobacillus sp. and test its anticancer activity in vitro. Because the arginine-degrading enzyme is a strong anticancer agent, it was isolated in two phases from a Lactobacillus sp. clinical isolate: 70% saturated ammonium sulphate precipitation followed by gel filtration chromatography (2x35cm). The most active fractions in enzyme activity (7.3 U/ ml), Purified enzyme had a special action activity of (48.6 U/mg) with nine folds of purgation and 61.4% enzyme recovery, The cytotoxic activity of purified arginine deiminase on PC3,A375 and WRL68 cells for 24 was examined. Purified arginine deiminase inhibited the proliferation of cancer cell lines PC3 and A375, with IC50 values of 68.64 g/ml and 136.3 g/ml, respectively. At a concentration of 6.25 ϻg/ml, 94.83% and 95.68% cell viability were observed of PC3 and A375 after treatment with purified arginine deiminase, respectively. However, cell viability reached to 42.52% and 48.77% using 400 ϻg/ml concentration purified arginine deiminase, respectively while ADI didn't show a significant effect on the viability of normal cell line.

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Park, Kitae, Pooreum Kim, Hyoung Gun Kim et JiHoon Kim. « Membrane Fouling Mechanisms in Combined Microfiltration-Coagulation of Algal Rich Water Applying Ceramic Membranes ». Membranes 9, n^o 2 (22 février 2019) : 33. http://dx.doi.org/10.3390/membranes9020033.

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In this paper, we investigated the membrane fouling mechanism according to the coagulant dosage in algal rich water using a ceramic membrane. The algae that were used in this experiment were Microcystis sp. of cyanobacteria, and the fouling mechanism was analyzed through irrigation and filtration resistance through a constant flow operation. The experimental results showed that the filtration resistance decreased as the coagulant dosage increased, but the irreversibility at above optimum coagulant dosage increased. Additionally, as the coagulant dosage increased, the resistance value due to cake and adsorption contamination decreased, and membrane fouling by adsorption was dominant in comparison with cake fouling and adsorption fouling. The specific cake resistance was decreased as the coagulant dosage increased. The characteristics of the cake layer according to the coagulant dosage were found to loosely form the cake layer by increasing micro-size algae as the coagulant dosage increased. The results of this experiment confirmed the membrane fouling mechanism according to coagulant dosage when the ceramic membrane filtered algal rich water.

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Zulkharnain, Azham, R. Maeda et T. Maeda. « Expression, purification and characterization of meta-cleavage enzyme CarBaBb from Novosphiongobium sp. KA1 ». Journal of Biochemistry, Microbiology and Biotechnology 1, n^o 1 (31 décembre 2013) : 11–16. http://dx.doi.org/10.54987/jobimb.v1i1.378.

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The meta-cleavage enzyme CarBaBb of carbazole-degrader Novosphiongobium sp. KA1 were cloned, expressed and purified to homogeneity in Escherichia coli strain. The enzyme was cloned with 6x histidine residues attached at the C-terminal of large subunit CarBb for purification using affinity chromatography method prior to gel filtration chromatography. The CarBaBb, a two-subunit meta-cleavage enzyme, approximately 30 kda for CarBb dan 10 kDa for CarBa, was found to be Î±2Î²2-heterotetrameric (Mr 80,000), showed highest activity at pH 8.5 and temperature 30Â°C. CarBaBb showed highest catalytic activity towards 2,3-dihydroxybiphenyl with kcat/Km 4.1 M-1s-1, and overall higher catalytic activities towards biphenyl-type substrates in comparison to catechol-type substrates. Based on the similarities, this meta-cleavage enzyme from Novosphiongobium sp. KA1 would also be a good candidate for protein crystallization and structural studies apart from CarBaBb from strain P. resinovorans strain CA10.

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Kafashi, Sahar, Ramin Taghdimi et Gholamreza Karimi. « Modification of Nanoclay Systems : An Approach to Stabilizing Drilling Fluids ». Advanced Materials Research 829 (novembre 2013) : 818–24. http://dx.doi.org/10.4028/www.scientific.net/amr.829.818.

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This study was aimed to investigate the rheological properties and the possibility of nano(Na, Ca )- bentonites nanoproducts to meet the required drilling mud properties. Sepiolite (Sp) and the mixture of 2% nanoNaB with 1% Sp were collected and prepared from Irans oil Company (NIOC). The nanoclay performance evaluation involved the experimental tests of the rheological properties, filtration and gel strength. According to the results obtained from flow properties tests for the mixture, it was indicated that the mixture was not adequate to be a suitable drilling fluid. The main objective was to make stable dispersions with nanobentonite and sepiolite by using a water soluble polymer as stabilizer. The changes in the rheological properties of bentonite were investigated at various concentrations of polyvinyl alcohol (PVA) to discover the stability of the dispersions. The standard API tests were applied for drilling fluid to determine the properties of dispersions.

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Harper, D. B., et J. T. Kennedy. « Purification and properties of S-adenosylmethionine : aldoxime O-methyltransferase from Pseudomonas sp. N.C.I.B. 11652 ». Biochemical Journal 226, n^o 1 (15 février 1985) : 147–53. http://dx.doi.org/10.1042/bj2260147.

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An enzyme catalysing the O-methylation of isobutyraldoxime by S-adenosyl-L-methionine was isolated from Pseudomonas sp. N.C.I.B. 11652. The enzyme was purified 220-fold by DEAE-cellulose chromatography, (NH4)2SO4 fractionation, gel filtration on Sephadex G-100 and chromatography on calcium phosphate gel. Homogeneity of the enzyme preparation was confirmed by isoelectric focusing on polyacrylamide gel and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The enzyme showed a narrow pH optimum at 10.25, required thiol-protecting agents for activity and was rapidly denatured at temperatures above 35 degrees C. The Km values for isobutyraldoxime and S-adenosyl-L-methionine were respectively 0.24 mM and 0.15 mM. Studies on substrate specificity indicated that attack was mainly restricted to oximes of C4-C6 aldehydes, with preference being shown for those with branching in the 2- or 3-position. Ketoximes were not substrates for the enzyme. Gel filtration on Sephadex G-100 gave an Mr of 84 000 for the intact enzyme, and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis indicated an Mr of 37 500, suggesting the presence of two subunits in the intact enzyme. S-Adenosylhomocysteine was a powerful competitive inhibitor of S-adenosylmethionine, with a Ki of 0.027 mM. The enzyme was also susceptible to inhibition by thiol-blocking reagents and heavy-metal ions. Mg2+ was not required for maximum activity.

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