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71.
Anna Radomińska-Pyrek Maria Pilarska Piotr Zimniak 《Biochemical and biophysical research communications》1978,85(3):1074-1081
Phosphoethanolaminetransferase of high specific activity was solubilized from rat liver microsomes with the non-ionic detergent octyl glucoside. The solubilization method is fast and simple, allowing for processing of large amounts of material. The solubilized enzyme is stable. It contains virtually no phosphocholinetransferase activity. A preliminary characterization of the enzyme, with both diacyl- and alkylacyl-glycerol as substrate, is given. For the reaction, the lipid substrates were incorporated into artificial phospholipid bilayers (liposomes). 相似文献
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Enrique J. La Motta 《Biotechnology and bioengineering》1976,18(10):1359-1370
A method for calculating the mass transfer coefficient in a biological film system, under turbulent flow conditions, is presented. It is experimentally found that fluid velocity has a positive effect on the rate of substrate utilization when the system is operated in other than the kinetic regime. A correlation is developed which indicates a dependence of the mass transfer coefficient on the fluid velocity raised to the 0.7 power. 相似文献
74.
The chain stiffness of linear native DNA is represented by a generalized bead and spring model recently proposed. It incorporates molecular rigidity by means of springs between beads, which are second neighbors along the contour of the chain. These springs are equivalent to elastic forces having longitudinal and transversal contributions. The model is compared with existing experimental data of sedimentation and low-angle light scattering to obtain the statistical parameters of DNA. The value of the statistical length obtained with this model is 1300 Å. The same value is obtained with the wormlike chain. Throughout this analysis, excluded volume is left out as a simplifying assumption. 相似文献
75.
Anna Junkiert-Czarnecka Maria Pilarska-Deltow Aneta Bk Marta Heise Anna Latos-Bieleska Jacek Zaremba Alicja Bartoszewska-Kubiak Olga Haus 《Current issues in molecular biology》2022,44(4):1472
Background: Ehlers-Danlos syndrome (EDS) is a common non-inflammatory, congenital connective tissue disorder. Classical type (cEDS) EDS is one of the more common forms, typically caused by mutations in the COL5A1 and COL5A2 genes, though causative mutations in the COL1A1 gene have also been described. Material and methods: The study group included 59 patients of Polish origin, diagnosed with cEDS. The analysis was performed on genomic DNA (gDNA) with NGS technology, using an Illumina sequencer. Thirty-five genes related to connective tissue were investigated. The pathogenicity of the detected variants was assessed by VarSome. Results: The NGS of 35 genes revealed variants within the COL5A1, COL5A2, COL1A1, and COL1A2 genes for 30 of the 59 patients investigated. Our panel detected no sequence variations for the remaining 29 patients. Discussion: Next-generation sequencing, with an appropriate multigene panel, showed great potential to assist in the diagnosis of EDS and other connective tissue disorders. Our data also show that not all causative genes giving rise to cEDS have been elucidated yet. 相似文献
76.
Mustapha Arkoun Laëtitia Jannin Philippe Laîné Philippe Etienne Céline Masclaux-Daubresse Sylvie Citerne Maria Garnica José-Maria Garcia-Mina Jean-Claude Yvin Alain Ourry 《Plant and Soil》2013,362(1-2):79-92
Background and aims
Urea is the major nitrogen (N) form supplied as fertilizer in agriculture. However, urease, a nickel-dependent enzyme, allows plants to use external or internally generated urea as a nitrogen source. Since a urease inhibitor is frequently applied in conjunction with urea fertilizer, the N-metabolism of plants may be affected. The aim of this study was to determine physiological and molecular effects of nickel deficiency and a urease inhibitor on urea uptake and assimilation in oilseed rape.Methods
Plants were grown on hydroponic solution with urea as the sole N source under three treatments: plants treated with nickel (+Ni) as a control, without nickel (?Ni) and with nickel and phenylphosphorodiamidate (+Ni+PPD). Urea transport and assimilation were investigated.Results
The results show that Ni-deficiency or PPD supply led to reduced growth and reduced 15N-uptake from urea. This effect was more pronounced in PPD-treated plants, which accumulated high amounts of urea and ammonium. Thus, Ni-deficiency or addition of PPD, limit the availability of N and decreased shoot and root amino acid content. The up-regulation of BnDUR3 in roots indicated that this gene is a component of the stress response to nitrogen-deficiency. A general decline of glutamine synthetase (GS) activity and activation of glutamate dehydrogenase (GDH) and increases in its expression level were observed in control plants. At the same time, in (?N) or (+Ni+PPD) treated plants, no increases in GS or GDH activities and expression level were found.Conclusions
Overall results showed that plants require Ni as a nutrient (while most widely used nutrient solutions are devoid of Ni), whether they are grown with or without a urea supply, and that urease inhibitors may have deleterious effects at least in hydroponic grown oilseed rape. 相似文献77.
Anna Reuleaux Heather Richards Terence Payet Pascal Villard Matthias Waltert Nancy Bunbury 《Ostrich》2014,85(3):245-253
Feeding ecology is an important factor for the survival of a species and knowledge of its parameters is a prerequisite for successful conservation work. In this study we describe the feeding ecology of the endemic Seychelles Black Parrot Coracopsis barklyi on Praslin, Seychelles, the only island on which this parrot is resident. We compared two methods to evaluate feeding choices: incidental observations and feeding walks on 25 transects in all habitat types. Black parrots fed on 46 different species, bringing the total number of known food plants to 53 species. They predominantly consumed endemic and native species (58% of observed feeding bouts), mainly their fruit pulp (in 68% of feeding bouts), followed by buds (15%) and seeds (37%) with occasional observations of leaves, bark and scale insects. The incidental method rendered many more observed bouts than the transect approach and the ratios of consumed species differed between methods but the transect results are regarded as more representative. The incidental method is not suitable for quantitative conclusions but complements the transect method, providing information about rarely occurring feeding events. 相似文献
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