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排序方式: 共有136条查询结果,搜索用时 15 毫秒
1.
Blagoja Boshkovski Constantinos Tzerakis Georgios Doupis Anhelina Zapolska Chariton Kalaitzidis 《Communications in Soil Science and Plant Analysis》2020,51(5):675-686
ABSTRACTSalinity and drought stresses are critical for Phaseolus vulgaris L. growth and development. They affect plants in various ways, including tissue mineral element content. Micro- and macro-elements in leaves of Phaseolus vulgaris L. (cv. ‘Blue lake’ and cv. ‘Terli’) subjected to deficit irrigation and salinity treatments were investigated, both analytically and with regards to their effect on the leaves’ spectral reflectance. B (boron), K (potassium), Mn (manganese), Na (sodium), Si (silicon) and Zn (zinc) appeared to be influenced by stress factors, mainly responding to salinity increase. The leaf spectral reflectance of the plants appeared to be significantly correlated with most of the elements under investigation. Multivariate regression identified a relationship of the reflectance at particular regions of the spectrum with phosphorus and NDVI (normalized difference vegetation index) and indicated a significant correlation with B, Fe (iron), K, Mn, P (phosphorus) and Zn. Moreover, customized spectral indices, exhibiting significantly high correlation with B, Fe, K, Mg (magnesium), Mn, Na, P, Zn and N (nitrogen), were developed. 相似文献
2.
Comparison between the urine dipstick and the pH‐meter to assess urine pH in sheep and dogs 下载免费PDF全文
3.
George Karabourniotis Georgios Liakopoulos Dimosthenis Nikolopoulos Panagiota Bresta 《林业研究》2020,31(1):1-12
As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions. 相似文献
4.
Konstantina Stamperna Eleni Dovolou Themistoklis Giannoulis Maria Kalemkeridou Ioannis Nanas Katerina Dadouli Katerina Moutou Zissis Mamuris Georgios S. Amiridis 《Reproduction in domestic animals》2021,56(10):1302-1314
The negative effects of heat stress on dairy cattle's fertility have been extensively studied, but the relevant knowledge for beef cattle is rather limited. The aims of this study were to investigate the effects of HS during in vitro maturation on the developmental potential of oocytes derived from Limousine and Holstein cows and to estimate the effect of the differential gene expression of important genes in oocytes, cumulus cells and blastocysts in the growth competence between the breeds. In seven replicates, cumulus oocyte complexes from Holstein and Limousine cows were matured for 24 hr at 39°C (controls C; Hol_39, Lim_39) or at 41°C from hour 2 to hour 8 of IVM (treated T; Hol_41, Lim_41), fertilized, and presumptive zygotes were cultured for 9 days at 39°C. Cleavage and embryo formation rates were evaluated 48 hr post-insemination and on days 7, 8 and 9, respectively. From all groups, subsets of cumulus cells, oocytes and blastocysts were analysed for the relative expression of genes related to metabolism, stress, apoptosis and placentation. No difference was detected in cleavage rate or in blastocyst formation rate among the control groups. In both breeds, heat stress reduced blastocyst yield, but at all days the suppression was higher in Limousines. In Holsteins, altered gene expression was detected in cumulus cells (G6PD, GLUT1) and blastocysts (PLAC8), while in Limousines, differences were found in oocytes (G6PD, HSP90AA1), in cumulus cells (CPT1B, HSP90AA1, SOD2) and blastocysts (DNMT, HSP90AA1, SOD2). It appears that Holstein COCs are more tolerant than Limousine COCs, possibly due to compulsory, production driven selection. 相似文献
5.
Ioannis Nanas Mariana Barbagianni Katerina Dadouli Eleni Dovolou Georgios S Amiridis 《Reproduction in domestic animals》2021,56(10):1329-1341
The objectives of this study were to assess alterations in, echogenic appearance, size and blood flow in the corpus luteum, the placentomes and the blood flow in umbilical and uterine arteries that heat stress can cause in cooled pregnant dairy cows. Pregnant cows were allocated in two groups and the gravid uteri, along with the ipsilateral corpora lutea were examined during the winter (group W, n = 9) or the summer (group S, n = 10). The grey-scale ultrasound and colour flow imaging of the corpus luteum and placentome were performed. In addition, the umbilical and uterine artery diameters and haemodynamic parameters in the vessels were calculated. At the time of ultrasonographic examination, cortisol concentrations were higher, and progesterone levels tended to be lower in group S compared to group W. The grey-scale ultrasound evaluation of corpora lutea and placentomes was lower in group S compared to group W. The diameter of umbilical artery and the blood volume in the vessel were less in group S than in group W. We infer that heat stress affects foetal blood supply and possibly the structure of placentomes and corpora lutea, but it differently affects the blood flow characteristics in the umbilical and uterine arteries. 相似文献
6.
Determination of anabolic steroids in muscle tissue by liquid chromatography-tandem mass spectrometry 总被引:1,自引:0,他引:1
Kaklamanos G Theodoridis G Papadoyannis IN Dabalis T 《Journal of agricultural and food chemistry》2007,55(21):8325-8330
A specific and sensitive method based on liquid chromatography-tandem mass spectrometry using atmospheric pressure chemical ionization (LC-APCI-MS/MS) has been developed for the determination of four anabolic steroids [trenbolone, methylboldenone, methyltestosterone, and norethandrolone] in bovine muscle. Methyltestosterone- d 3 was used as internal standard. The procedure involved enzymatic hydrolysis, extraction with tert-butyl methyl ether, defattening, and final cleanup with solid-phase extraction with Oasis HLB cartridges. The analytes were analyzed by reversed-phase LC-MS/MS, acquiring two diagnostic product ions from the chosen precursor [M + H] (+) for the unambiguous confirmation of hormones. The method was validated according to the European Commission Decision 2002/657/EC for the detection and confirmation of residues in products of animal origin. The limits of detection (LOD) and limits of quantitation (LOQ) were found to be 0.3 ng/g and 1.0 ng/g, respectively. The accuracy and precision have been determined, with recoveries ranging from 83% to 104% and the CV factor not exceeding the value of 7%. The decision limits CCalpha were calculated and ranged from 0.05 to 0.15 ng/g while the detection capabilities CCbeta ranged from 0.09 to 0.25 ng/g. The method proved to be sensitive and reliable and thus renders an appropriate means for residue analysis studies. 相似文献
7.
Graciliana Lopes Georgios Daletos Peter Proksch Paula B. Andrade Patrícia Valent?o 《Marine drugs》2014,12(3):1406-1418
A monoacylglycerol (1) and a 1:1 mixture of two monogalactosyl diacylglycerols (MGDGs) (2 and 3) were isolated from the brown seaweed Fucus spiralis Linnaeus. The structures were elucidated by spectroscopic means (NMR and MS) and by comparison with the literature. Compound 1 was composed of a glycerol moiety linked to oleic acid (C18:1 Ω9). Compounds 2 and 3 contained a glycerol moiety linked to a galactose unit and eicosapentaenoic acid (C20:5 Ω3) combined with octadecatetraenoic acid (C18:4 Ω3) or linolenic acid (C18:3 Ω3), respectively. The isolated compounds were tested for their cytotoxic and anti-inflammatory activity in RAW 264.7 macrophage cells. All of them inhibited NO production at non-cytotoxic concentrations. The fraction consisting of compounds 2 and 3, in a ratio of 1:1, was slightly more effective than compound 1 (IC50 of 60.06 and 65.70 µg/mL, respectively). To our knowledge, this is the first report of these compounds from F. spiralis and on their anti-inflammatory capacity. 相似文献
8.
Interactions between residue placement and earthworm ecological strategy affect aggregate turnover and N2O dynamics in agricultural soil 总被引:1,自引:0,他引:1
Georgios Giannopoulos 《Soil biology & biochemistry》2010,42(4):618-625
Previous laboratory studies using epigeic and anecic earthworms have shown that earthworm activity can considerably increase nitrous oxide (N2O) emissions from crop residues in soils. However, the universality of this effect across earthworm functional groups and its underlying mechanisms remain unclear. The aims of this study were (i) to determine whether earthworms with an endogeic strategy also affect N2O emissions; (ii) to quantify possible interactions with epigeic earthworms; and (iii) to link these effects to earthworm-induced differences in selected soil properties. We initiated a 90-day 15N-tracer mesocosm study with the endogeic earthworm species Aporrectodea caliginosa (Savigny) and the epigeic species Lumbricus rubellus (Hoffmeister). 15N-labeled radish (Raphanus sativus cv. Adagio L.) residue was placed on top or incorporated into the loamy (Fluvaquent) soil. When residue was incorporated, only A. caliginosa significantly (p < 0.01) increased cumulative N2O emissions from 1350 to 2223 μg N2O-N kg−1 soil, with a corresponding increase in the turnover rate of macroaggregates. When residue was applied on top, L. rubellus significantly (p < 0.001) increased emissions from 524 to 929 μg N2O-N kg−1, and a significant (p < 0.05) interaction between the two earthworm species increased emissions to 1397 μg N2O-N kg−1. These effects coincided with an 84% increase in incorporation of residue 15N into the microaggregate fraction by A. caliginosa (p = 0.003) and an 85% increase in incorporation into the macroaggregate fraction by L. rubellus (p = 0.018). Cumulative CO2 fluxes were only significantly increased by earthworm activity (from 473.9 to 593.6 mg CO2-C kg−1 soil; p = 0.037) in the presence of L. rubellus when residue was applied on top. We conclude that earthworm-induced N2O emissions reflect earthworm feeding strategies: epigeic earthworms can increase N2O emissions when residue is applied on top; endogeic earthworms when residue is incorporated into the soil by humans (tillage) or by other earthworm species. The effects of residue placement and earthworm addition are accompanied by changes in aggregate and SOM turnover, possibly controlling carbon, nitrogen and oxygen availability and therefore denitrification. Our results contribute to understanding the important but intricate relations between (functional) soil biodiversity and the soil greenhouse gas balance. Further research should focus on elucidating the links between the observed changes in soil aggregation and controls on denitrification, including the microbial community. 相似文献
9.
Isolation of viruses from outbreaks of suspected tenosynovitis (viral arthritis) in chickens 总被引:1,自引:1,他引:0
Specimens from the legs of chickens from 84 outbreaks of suspected tenosynovitis were examined for the presence of viruses by culture in chick embryo lung or liver cell monolayers. All samples were from broilers or broiler breeders, ranging in age from dead-in-shell embryos to 36 weeks old. Twenty-five outbreaks (29.8 per cent) yielded viruses of which 12 were reoviruses alone, 12 adenoviruses alone, and one, a mixture of both types of virus. Rupture of the gastrocnemius tendon was seen in 12 outbreaks and viruses were isolated from six of these: three were reoviruses and three were adenoviruses. Approximately half the affected flocks from which specimens were received were in the six to 14 week age range. With one exception, all the reovirus isolations were made from chickens of 11 weeks or under, while adenovirus isolations showed more scatter with regard to age. 相似文献
10.
A. Al-Waeli E. Zoidis C.A. Georgiou K. Fegeros G. Zervas 《British poultry science》2012,53(6):817-827
1. The study was part of a project designed to investigate if organic selenium (Se) can ameliorate the toxic effects of cadmium (Cd). The main objective of the present study was to investigate, in the chicken, the interactions between Se, Cd and the following elements: Sb, Ca, Cr, Co, Cu, Fe, Pb, Mg, Mn, Mo, Ni, V and Zn. 2. A total of 300 1-d-old chickens (broilers) were randomly distributed among 4 dietary treatments with 5 replicate pens per treatment. In T1, chickens were fed on a diet with 0·3?mg/kg added Se, without added Cd. In T2, chickens were fed on a diet with 0·3?mg/kg Se and 10?mg/kg Cd. In T3, chickens were fed on a diet with 0·3?mg/kg Se and 100?mg/kg of Cd added and in T4 treatment, chickens were fed on a diet with 3?mg/kg Se and 100?mg/kg Cd added. Se was added as Se-yeast. Cd was added as cadmium chloride (CdCl2). On d 28 and 42, two chickens per replicate pen were killed for collection of whole blood, liver, kidney and breast muscle samples. Samples were analysed by ICP-MS. The data were analysed using a multivariate linear model. 3. While low Cd concentrations in the diet led only to an increase of Cd concentration in the examined tissues, addition of high concentrations of Cd increased the concentration of Cd, Cu, Sb and V and decreased that of Se, Mn and Fe. Addition of high Se concentrations did not significantly reduce Cd concentration. 4. Prior to model application, correlations of 78 elements were noted, while after model application 39 correlations were noted. Most notably, Cd was correlated with Ca, Co, Cu and Mg, while Se was correlated with Mn. 5. The present study revealed several correlations between essential, probably essential and toxic elements illustrating the importance of the balance between pro-oxidants and antioxidants. 相似文献