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71.
Background
Finding the amino acid mutations that affect the severity of influenza infections remains an open and challenging problem. Of special interest is better understanding how current circulating influenza strains could evolve into a new pandemic strain. Influenza proteomes from distinct viral phenotype classes were searched for class specific amino acid mutations conserved in past pandemics, using reverse engineered linear classifiers. 相似文献72.
Andrade CM Lopez PL Noronha BT Wink MR Borojevic R Margis R Lenz G Battastini AM Guma FC 《Cell and tissue research》2011,344(2):279-286
Ecto-5′-nucleotidase (eNT/CD73, E.C.3.1.3.5) is a glycosyl phosphatidylinositol (GPI)-linked cell-surface protein with several
functions, including the local generation of adenosine from AMP, with the consequent activation of adenosine receptors and
the salvaging of extracellular nucleotides. It also apparently functions independently of this activity, e.g., in the mediation
of cell-cell adhesion. Liver fibrosis can be considered as a dynamic and integrated cellular response to chronic liver injury
and the activation of hepatic stellate cells (HSCs) plays a role in the fibrogenic process. eNT/CD73 and adenosine are reported
to play an important role in hepatic fibrosis in murine models. Knockdown of eNT/CD73 leads to an increase in mRNA expression
of tissue non-specific alkaline phosphatase (TNALP), another AMP-degrading enzyme and thus no alteration is seen in the total
ecto-AMPase activity of the cell. eNT/CD73 knockdown also leads to changes in the expression of collagen I and a clear alteration
of cell migration. We suggest that eNT/CD73 protein expression controls cell migration and collagen expression in a mechanism
independent of changes in nucleotide metabolism. 相似文献
73.
The timing of breeding may not only affect breeding patterns such as the overlap of chick rearing period with the peak in
food availability but also the opportunity for extra-pair mating. A negative relationship has been predicted between extra-pair
paternity and breeding synchrony, assuming that male extra-pair activity is traded against mate guarding and parenting duties.
In contrast, if female ability to assess male quality is temporally constrained, sperm competition might be a positive function
of breeding synchrony. Here we manipulated the progress of nesting by nest material exchange within nesting aggregations to
see whether the timing of breeding affects extra-pair paternity in house sparrows. We found that late broods within nesting
clusters contained extra-pair young more often than early broods, but breeding synchrony did not turn out to be a significant
predictor of extra-pair paternity. Our study indicates that temporal constraints of male extra-pair activity may account for
extra-pair paternity levels, but it is also possible that late-breeding females may accept extra-pair copulations to ensure
egg fertilization. 相似文献
74.
75.
The trapezoidal Candoninae from the Turiec Basin in Slovakia referred to the Candona sitari- and to C. aculeata-groups have characters that contrast with the valves of the Recent central European Candonines. The particularities concern the degree of calcification, the zone of concrescence, the overlap, and the presence of protuberances, the dorsum and the tubercles. Within the sitari-group, these characters evolve simultaneously with rapid evolution of the valve outline from subtrapezoidal to trapezoidal in shape. The species of this group acquire valve contours similar to those of the trapezoidal Candoninae of the Lake Pannon and the recent fauna of the long-lived lakes. The trapezoidal Candoninae of the Turiec Basin are associated with candonines that have triangular and rectangular carapaces with a pointed posteroventral margin. These three morphotypes indicate relatively stable habitats with weak environmental fluctuations. The trapezoidal species are rare in the littoral facies in both the north and the marginal areas of the Turiec Basin, but very abundant in the centre and south of the Basin. They probably lived in a profundal environment and their evolution probably occurred in relation to both sexual reproduction and a benthonic mode of life. The two groups comprise 18 species, of which 15 are described as new. 相似文献
76.
Simone Martinelli Oliver H.F. Krumbach Francesca Pantaleoni Simona Coppola Ehsan Amin Luca Pannone Kazem Nouri Luciapia Farina Radovan Dvorsky Francesca Lepri Marcel Buchholzer Raphael Konopatzki Laurence Walsh Katelyn Payne Mary Ella Pierpont Samantha Schrier Vergano Katherine G. Langley Douglas Larsen Ghayda M. Mirzaa 《American journal of human genetics》2018,102(2):309-320
77.
Radovan Hynek Václav Kaši?ka Zdenka Ku?erová Jan Káš 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,688(2):1662
A combination of reversed-phase high-performance liquid chromatography (RP-HPLC) and capillary zone electrophoresis (CZE) was used for characterization of α-chymotryptic digests of human pepsinogen A, human pepsinogen C (both isolated from stomach mucosa of patients suffering from gastric cancer), swine pepsinogen and their dephosphorylated forms. Combining RP-HPLC and CZE for peptide mapping allowed to detect phosphorylations in molecules of the above mentioned gastric zymogens. We have found one phosphate group in the molecule of human pepsinogen A and two phosphate groups in the molecule of human pepsinogen C. The investigated sample was obtained from stomach mucosa of a patient suffering from gastric cancer. An increased number of phosphate groups in molecules of human pepsinogen seems to be associated with gastric cancer. The developed method represent a suitable tool for studying relationships between specific phosphorylations of proteins and cancerogenesis or potentially could serve for early diagnosis of gastric cancer. 相似文献
78.
Irreversible thermodynamic model equations of the transport across a horizontally mounted membrane 总被引:1,自引:0,他引:1
A Slezak 《Biophysical chemistry》1989,34(2):91-102
The Kedem-Katchalsky-Zelman model equations for transmembrane transport in multicomponent, non-ionic and heterogeneous solutions have been modified. The validity of this model for binary and ternary solutions was verified, using a cell with a horizontally mounted membrane. In the cell, volume and solute fluxes were measured as a function of gravitational configuration. In the experimental set-up, water was placed on one side of the membrane. The opposite side of the membrane was exposed to aqueous solutions of densities greater than that of water, aqueous ethanol (less dense than water) or glucose/ethanol/water solutions. The experimental results presented herein illustrate pseudo-phase transitions which occur from a non-convectional to convectional state or in the reverse direction. 相似文献
79.
This paper is concerned with the definition of the standard conditions required for optimum operation of the bare platinum electrode with photosynthetic samples. Experimental evidence shows the following: 1) Polarization circuits should have zero resistance; 2) The electrolyte layer between the electrodes should have a conductance higher than 54×10–6 –1 per mm2 of platinum electrode area; 3) The electrodes should be polarized just before taking the measurements. All these facts can be interpreted in terms of phenomena occurring on the electrode: The adsorption of hydrogen on the electrode imposes the need for low resistances in the system, and oxygen consumption by the electrode is minimized by polarizing the electrodes as late as possible. This investigation increases the reliability of the bare platinum electrode and gives a basis for a comparison of the results from different experiments. Demonstrations of the pertinence of these conditions are made in our lab with the algae Dunaliella Tertiolecta. 相似文献
80.
Oxygen evolution in Dunaliella tertiolecta under flashing light was measured with a bare electrode, at a 10 Hz frquency. The sigma coefficients of the oxygen evolution recurrence law (Thibault (1978) J Theor Biol 73, 271) were determined using groups of nine consecutive points. The S-state transition probabilities were computed from the sigma coefficients and plotted as a function of the flash number of the first of the points used. Low standard deviations over the sigma coefficients resulted from the use of our system (Meunier & Popovic (1988) Rev Sci Instr 59, 486). We observed a linear lowering of the miss probability with time, and a linear rise of the single-hit probability with the same absolute value of the slope. The hypothesis that the slopes were zero was statistically tested and was rejected with a 99.9% confidence interval. Our work demonstrates that, to be accurate, an oxygen evolution model has to take the variations in the properties of S-states into account.International Journal of Fracture 76 (1995) R37 相似文献