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1.
Klejdus B Mikelová R Petrlová J Potesil D Adam V Stiborová M Hodek P Vacek J Kizek R Kubán V 《Journal of agricultural and food chemistry》2005,53(15):5848-5852
An ultrafast HPLC/UV-vis DAD method working at 254 nm was applied for the determination of isoflavone aglycons and glycosides (genistin, genistein, daidzein, daidzin, glycitin, glycitein, ononin, formononetin, sissotrin, and biochanin A) in roots, stems, leaves, and soy pods of soy plants and in soybeans of five varieties (Korada, Quito, Rita, OAC Erin, and OAC Vison). An Atlantis dC18 ultrafast RP chromatographic column (20 mm x 2.1 mm, 3 microm particle size) was applied for separation of the isoflavone aglycons and glycosides. A flow rate of the mobile phase (0.1% (v/v) acetic acid, pH 3.75-solvent A and methanol-solvent B) was 0.35 mL min(-1), and the column temperature was 36 degrees C. A linear gradient profile from 13 up to 22% B (v/v) from zero to 2.5 min, up to 30% B to 3.21 min, up to 35% B to 4 min, up to 40% B to 4.5 min, up to 50% B to 5.14 min, and followed by negative gradient up to 13% B to 7.71 min was used. The absolute limits of detection per sample injection (5 microL) were the highest for biochanin A (166.2 fmol) and the lowest for genistin (17.0 fmol), respectively. An accelerated solvent extraction (ASE) in combination with sonication was applied for isolation of biologically active compounds. A solid-phase extraction procedure was used to purify the extracts in the case of analysis of soy plants parts. The recoveries of 96-106% were obtained for the different concentrations of the isoflavone aglycons and glycosides and the different matrixes (overall RSDs 2-9%). The highest isoflavone concentrations were found in roots (12.5 microg g(-1) dry weight), while the amounts were about 3-1100 microg g(-1) fresh weight in different varieties of soybeans. 相似文献
2.
Gas chromatographic determination of technical pyrazon (5-amino-4-chloro-2-phenyl-3(2H)pyridazinone)
5-Amino-4-chloro-2-phenyl-3(2H)pyridazinone (common name pyrazon) is the active ingredient of herbicide formulations known under the trade names Burex, Chlorazine, Pyramin, Phenazon. Pyrazon content was evaluated using the internal standard 4-chloro-5-methylamino-2-phenyl-3(2H)pyridazinone. FID detector and glass column (50 × 0.25 cm) packed with 2% cyclohexane-di-methanol succinate on silanised Chromosorb G (80-100 mesh) were used. Technical products can contain two interesting impurities, the non-active pyrazon isomer 4-amino-5-chloro-2-phenyI-3(2H)pyridazinone and the unreacted 4,5-dichloro-2-phenyl-3(2H)pyridazinone, the later of which issignificant from the point of view of toxicology. Determination of these two compounds under the conditions used for pyrazon is practically impossible. They were therefore determined on a separate glass column (70 × 0.24 cm) packed with 5% cyclohexane-di-methanol succinate on Chromosorb G (60-80 mesh). A standard addition method for small concentrations of 4,5-dichloro-2-phenyl-3(2H) pyridazinone in technical pyrazon products is also described. 相似文献
3.
Novotny V Drozd P Miller SE Kulfan M Janda M Basset Y Weiblen GD 《Science (New York, N.Y.)》2006,313(5790):1115-1118
Despite recent progress in understanding mechanisms of tree species coexistence in tropical forests, a simple explanation for the even more extensive diversity of insects feeding on these plants has been missing. We compared folivorous insects from temperate and tropical trees to test the hypothesis that herbivore species coexistence in more diverse communities could reflect narrow host specificity relative to less diverse communities. Temperate and tropical tree species of comparable phylogenetic distribution supported similar numbers of folivorous insect species, 29.0 +/- 2.2 and 23.5 +/- 1.8 per 100 square meters of foliage, respectively. Host specificity did not differ significantly between community samples, indicating that food resources are not more finely partitioned among folivorous insects in tropical than in temperate forests. These findings suggest that the latitudinal gradient in insect species richness could be a direct function of plant diversity, which increased sevenfold from our temperate to tropical study sites. 相似文献
4.
Predictions of the orbit of the Transit 1B satellite were systematically in error until account was taken of a third-order gravitational harmonic. The amplitude deduced for this harmonic by O'Keefe from the Vanguard I orbit serves very well, even though the orbits and the methods of observation and orbit fitting for the two satellites are quite different. 相似文献
5.
Pikula J Adam V Bandouchova H Beklova M Horakova J Horakova H Kizek R Krizkova S Skocovska B Supalkova V Svoboda M Tremi F Vitula F 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2007,36(4):361-363
Background: Many causes of mortality in the European brown hare, such as bacterial and viral infections, anticoagulant poisoning, and trauma, may result in hemorrhage. There are, however, no reference values concerning blood clotting in this species. Objectives: The aim of this study was to determine reference values for blood coagulation times and related parameters in healthy European brown hares. Methods: Blood samples from 30 clinically healthy adult hares (15 males and 15 females) were obtained. Hares were physically restrained for blood collection from the cephalic vein into tubes containing citrate and EDTA. Results: Mean ± SD were obtained for thrombin time (TT) (13.97 ± 1.37 seconds), prothrombin time (PT) (13.32 ± 2.15 seconds), activated partial thromboplastin time (APTT) (16.73 ± 1.86 seconds), fibrinogen concentration (2.98 ± 1.06 g/L), and platelet count (355.28 ± 128.73 × 109 /L). Conclusions: Reference values for blood coagulation times and other parameters associated with blood clotting will be useful in the laboratory evaluation of hemorrhage in the European brown hare. 相似文献
6.
The goal of this paper describes kinematic viscosity and shear stress of two used engine oils, which have been taken from two different passenger cars. Kinematic viscosity and shear stress are two of the most important physical behaviours of fluids, especially lubricating fluids. In this paper the authors have focused on engine oil. Knowledge of these properties of engine oil is very important due to its lifetime. The experiments have been done using digital rotary rheometer Anton Paar DV-3 P with use of TR8 spindle and special adapter for a small amount of sample （20 mL）. Two different engine oils have been observed--first from passenger car Renault Scenic with petrol engine （engine capacity 1.6 dm3） and the second from passenger car Skoda Roomster with diesel engine （engine capacity 1.4 dm3）. Castrol Magnatec 10W-40 engine oil has been taken from Renault car and Shell Helix Ultra Extra 5W-30 engine oil has been taken from ~koda car. Service interval of change oil has been set to 15,000 km and samples of used engine oils have been taken after 1,500 km. Only first samples of used engine oils have been taken after raid of 20 km. All samples of used engine oils have been compared with new （unused） engine oils same specification. The measured values of kinematic viscosity and shear stress have been modeled using linear function. The coefficients of correlation R have been achieved high values （0.88-0.96）. The obtained models can be used to prediction of engine oil flow behaviour. 相似文献
7.
Juliane Röder Claus Bässler Roland Brandl Libor Dvořak Andreas Floren Martin M. Goßner Axel Gruppe Andrea Jarzabek-Müller Oldřich Vojtech Christian Wagner Jörg Müller 《Forest Ecology and Management》2010
Norway Spruce is the economically most important tree species in Europe and has been cultivated in plantations on a large-scale at low elevations, far outside its natural range. In the Bohemian Forest, it naturally occurs in pure stands above 1150 m a.s.l. and as a mixed tree species from 650 to 1150 m a.s.l. An understanding of natural distributions and the diversity along temperature gradients at various elevations is important for conservation, pest management, and predictions of future species assemblages by global warming. Here we investigated the species richness of canopy arthropods in spruce trees along a gradient from 300 to 1300 m a.s.l. using flight-interception traps. We analyzed species richness by combining diversity partitioning with a moving window approach after standardizing sample size per plot. Total richness decreased linearly as the elevation increased, which reflected declining temperatures and a declining regional species pool. Phytophages (herbivores excluding xylophages) were the most influenced. Richness did not peak at the transition zones of the three ecological elevation zones, neither for all species, nor for any of the separate functional groups. However, the proportion of both beetle and true bug spruce specialists significantly increased with elevation and actually doubled in richness above 1000 m a.s.l., where spruce is naturally dominating. Our results indicate that even planted spruce trees at lower elevations maintain high levels of species richness. Further climate warming will promote overall species richness, especially of phytophages, at all elevations. However, spruce specialists may be seriously threatened by global warming. 相似文献
8.
Lucie Kupcikova Vojtech Anderle Tomas Vlcko Ludmila Ohnoutkova Martin Svidrnoch 《British poultry science》2017,58(6):712-717
1. The objective of this study was to determine the coefficient of pre-caecal digestion of P in maize (3.9 g/kg of total P, 0.83 g/kg of phytate P, 138 FTU [phytase units]/kg) and wheat (3.17 g/kg of total P, 1.94 g/kg of phytate P, 666 FTU/kg) in broilers according to the WPSA protocol.
2. For the diets, monosodium phosphate was used as an additional P supplement. Two sets of diets containing 200, 460 and 740 g/kg of wheat or 200, 500 and 740 g/kg of maize were formulated. A total of 288 21-d-old male broilers (Ross 308) were assigned to 24 cages (8 birds per cage) and the 6 test diets were assigned to cages. The coefficient of pre-caecal digestion of P was determined by the indicator method and linear regression.
3. In both ingredients, pre-caecal digestible P increased linearly with increasing inclusion levels of maize or wheat (P < 0.05). The coefficients of digestion of pre-caecal P were estimated to be 0.18 for wheat and 0.33 for maize. 相似文献
9.
Variation in cold hardiness and carbohydrate concentration from dormancy induction to bud burst among provenances of three European oak species 总被引：1，自引：0，他引：1
Morin X Améglio T Ahas R Kurz-Besson C Lanta V Lebourgeois F Miglietta F Chuine I 《Tree physiology》2007,27(6):817-825
Although cold hardiness is known to be a major determinant of tree species distribution, its dynamics and the factors that regulate it remain poorly understood. Variation in cold hardiness and carbohydrate concentration, from dormancy induction until bud burst, were investigated in populations of two deciduous (Quercus robur L. and Quercus pubescens Willd.) and one evergreen (Quercus ilex L.) European oak. Mean cold hardiness values in January were -56, -45 and -27 degrees C for Q. robur, Q. pubescens and Q. ilex, respectively. Soluble carbohydrate concentrations were closely related to instantaneous cold hardiness, estimated by the electrolyte leakage method, whereas total carbohydrate concentration was related to maximum cold hardiness. Both cold hardiness and carbohydrate concentration showed a close linear relationship with temperatures at the location of the sampled population. Our results show that temporal variation in both the inter- and intraspecific cold hardiness in European oaks can be related to variations in the concentrations of soluble carbohydrates and that these relationships appear to be driven by temperature. 相似文献
10.
Psenicka M Rodina M Flajshans M Kaspar V Linhart O 《Fish physiology and biochemistry》2009,35(4):591-597
Spermatozoa of common carp Cyprinus carpio are typically consist of a primitive head without acrosome, a midpiece with several mitochondria, a centriolar complex (proximal
and distal centriole), and one flagellum. During an evaluation of the motility of common carp spermatozoa, we found spermatozoa
with more than one flagellum and/or “double head” in three different individuals. This may be related to abnormal spermatogenesis.
Ultrastructure and physiological parameters of spermatozoa were examined using light microscopy (dark field with stroboscopic
illumination), transmission and scanning electron microscopy, and flow cytometry. The recorded pictures and videos were evaluated
using Olympus MicroImage software. All spermatozoa with more than one flagellum had a larger head and shorter flagella. They
occasionally demonstrated several cytoplasmic channels separating the flagella from the midpiece. Each flagellum was based
upon its own centriolar complex, with the connection of the flagellum to the head always at a constant angle. The flagella
always consisted of nine peripheral pairs and one central doublet of microtubules. Sperm exhibited a relative DNA content
similar to that found in sperm from normal males, with higher coefficients of variation. Although similar abnormalities have
been found in livestock, where they were described as a defect in spermiogenesis, no comparable results have been reported
in fish. The frequency at which these abnormalities occurs, the fertilization ability of males with defects in spermiogenesis,
the influence of these abnormalities on progeny in terms of ploidy level, and the occurrence of deformities warrant further
investigation. 相似文献