1,679 research outputs found
Phenolic compounds and its antioxidant activities in ethanolic extracts from seven cultivars of Chinese jujube
AbstractPhenolic compounds and its antioxidant activity of extracts from seven cultivars of Chinese jujubes were investigated by high performance liquid chromatography (HPLC) with standards and different antioxidant evaluation methods, such as phosphomolybdenum assay, superoxide radical scavenging activity (SRSA), hydroxyl radical scavenging activity (HRSA), antihemolytic activity and inhibition of lipid peroxidation in rat liver homogenate, respectively. The results showed the components of the extracts are comprised of total phenols and flavonoids, and its content ranges from 454.3 to 1298.9 (GAEmg/100g dry weight). Phlorizin, catechin, gallic acid, chlorogenic acid, caffeic acid were the predominant phenolic compounds. All the extracts had significant antioxidant activities either in vitro or in vivo. Correlation analysis indicated that the antioxidant capacities of Chinese jujube extracts demonstrated a good positive relationship with some phenolic acids, which was higher in Xiao and Goutou. The results indicated that Xiao and Goutou could be attributed to a potential source of natural antioxidants for food applications
Bis[N′-(3-cyanobenzylidene)isonicotinohydrazide-κN]silver(I) trifluoromethanesulfonate
In the title compound, [Ag(C14H10N4O)2]CF3SO3, two N atoms from two independent pyridyl rings of two N′-3-cyanobenzylideneisonicotinohydrazide ligands coordinate to the unique AgI ion, forming a nearly linear coordination geometry. Adjacent silver complexes are primarily linked together by Ag⋯N interactions, with Ag⋯N separations of 2.877 (2) and 3.314 (2) Å. On the other hand, one CF3SO3
− anion interacts with hydrazone groups of two neighbouring ligands via N—H⋯O hydrogen bonds. These weak intermolecular interactions contribute to the formation of supramolecular chains. In addition, there are Ag⋯O interactions [2.787 (2) Å] between Ag and O atoms from adjacent chains
Empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs and giants based on interferometric data
We present empirical metallicity-dependent calibrations of effective
temperature against colours for dwarfs of luminosity classes IV and V and for
giants of luminosity classes II and III, based on a collection from the
literature of about two hundred nearby stars with direct effective temperature
measurements of better than 2.5 per cent. The calibrations are valid for an
effective temperature range 3,100 - 10,000 K for dwarfs of spectral types M5 to
A0 and 3,100 - 5,700 K for giants of spectral types K5 to G5. A total of
twenty-one colours for dwarfs and eighteen colours for giants of bands of four
photometric systems, i.e. the Johnson (), the Cousins
(), the Sloan Digital Sky Survey (SDSS, ) and the Two
Micron All Sky Survey (2MASS, ), have been calibrated. Restricted
by the metallicity range of the current sample, the calibrations are mainly
applicable for disk stars ([Fe/H]). The normalized percentage
residuals of the calibrations are typically 2.0 and 1.5 per cent for dwarfs and
giants, respectively. Some systematic discrepancies at various levels are found
between the current scales and those available in the literature (e.g. those
based on the infrared flux method IRFM or spectroscopy). Based on the current
calibrations, we have re-determined the colours of the Sun. We have also
investigated the systematic errors in effective temperatures yielded by the
current on-going large scale low- to intermediate-resolution stellar
spectroscopic surveys. We show that the calibration of colour ()
presented in the current work provides an invaluable tool for the estimation of
stellar effective temperature for those on-going or upcoming surveys.Comment: 28 pages, 19 figures, 8 tables, accepted for publication in MNRA
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Calcineurin B-Like Proteins CBL4 and CBL10 Mediate Two Independent Salt Tolerance Pathways in Arabidopsis.
In Arabidopsis, the salt overly sensitive (SOS) pathway, consisting of calcineurin B-like protein 4 (CBL4/SOS3), CBL-interacting protein kinase 24 (CIPK24/SOS2) and SOS1, has been well defined as a crucial mechanism to control cellular ion homoeostasis by extruding Na+ to the extracellular space, thus conferring salt tolerance in plants. CBL10 also plays a critical role in salt tolerance possibly by the activation of Na+ compartmentation into the vacuole. However, the functional relationship of the SOS and CBL10-regulated processes remains unclear. Here, we analyzed the genetic interaction between CBL4 and CBL10 and found that the cbl4 cbl10 double mutant was dramatically more sensitive to salt as compared to the cbl4 and cbl10 single mutants, suggesting that CBL4 and CBL10 each directs a different salt-tolerance pathway. Furthermore, the cbl4 cbl10 and cipk24 cbl10 double mutants were more sensitive than the cipk24 single mutant, suggesting that CBL10 directs a process involving CIPK24 and other partners different from the SOS pathway. Although the cbl4 cbl10, cipk24 cbl10, and sos1 cbl10 double mutants showed comparable salt-sensitive phenotype to sos1 at the whole plant level, they all accumulated much lower Na+ as compared to sos1 under high salt conditions, suggesting that CBL10 regulates additional unknown transport processes that play distinct roles from the SOS1 in Na+ homeostasis
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