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排序方式: 共有221条查询结果,搜索用时 15 毫秒
211.
Janne J. Koskimäki Juho Hokkanen Laura Jaakola Marja Suorsa Ari Tolonen Sampo Mattila Anna Maria Pirttilä Anja Hohtola 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(4):629-640
Bilberry (Vaccinium myrtillus) represents one of the richest flavonoid sources among plants. Flavonoids play variable, species-dependent roles in plant
defences. In bilberry, flavonoid metabolism is activated in response to solar radiation but not against mechanical injury.
In this paper, the defence reaction and biosynthesis of phenolic compounds of bilberry was studied after infection by a fungal
endophyte (Paraphaeosphaeria sp.) and a pathogen (Botrytis cinerea). The defence response of bilberry was faster against the endophyte than the pathogen. All flavonoid biosynthesis genes tested
were activated by each infection. Biosynthesis and accumulation of phenolic acids, flavan-3-ols and oligomeric proanthocyanidins
were clearly elevated in both infected samples. Infection by the pathogen promoted specifically accumulation of epigallocatechin,
quercetin-3-glucoside, quercetin-3-O-α-rhamnoside, quercetin-3-O-(4”-HMG)-R-rhamnoside, chlorogenic acid and coumaroyl quinic
acid. The endophyte-infected plants had a higher content of quercetin-3-glucuronide and coumaroyl iridoid. Therefore, accumulation
of individual phenolic compounds could be specific for each infection. Quantity of insoluble proanthocyanidins was the highest
in control plants, suggesting that they might act as storage compounds and become activated by degradation upon infection. 相似文献
212.
Nowadays, only little information regarding the climber Clitoria ternatea L. var. pleniflora Fantz as “new ornamental plant” does exist in the German-speaking area. This plant is from interest because of its characteristic attractive, bright blue flowers. The vegetative propagation of Clitoria ternatea was investigated at the Institute for Horticultural Sciences, Humboldt-University of Berlin. The objective was to study how different types of cuttings could influence the rooting, proliferation and growth behaviour of greenhouse plants cultivated in two different seasons (summer and autumn). It was found that either stem or tip cuttings from the lower and middle zones of the mother plants with a fully developed leaf are suitable for summer or autumn propagation. Also, it was shown that the cutting variants affected the branching behaviour and further plant growth. Nearly 90% of the trial plants remained with a single shoot. However, in the vegetation period 11% of the plants originating from tip cutting and 14% of the plants originating from stem cuttings could be found with two branches. In autumn, the formation of lateral shoots was strongly declining. Here, the shoot length was particularly influenced by using different types of cutting treatments during propagation. The stem cuttings of the first batch planted clearly developed plants with longer shoots compared to those growing from tip cuttings. In the second batch planted, a lower shoot length growth was generally recorded (means of 5 to 6?cm for the internodes after three-month cultivation). In conclusion, the results regarding the propagation show that C.?ternatea can be recommended as a new ornamental container plant. However, further studies should follow in order to investigate possible photoperiod effects as well as suitable cultivation measures. 相似文献
213.
Teifke JP Klopfleisch R Globig A Starick E Hoffmann B Wolf PU Beer M Mettenleiter TC Harder TC 《Veterinary pathology》2007,44(2):137-143
Mortality in wild aquatic birds due to infection with highly pathogenic avian influenza viruses (HPAIV) is a rare event. During the recent outbreak of highly pathogenic avian influenza in Germany, mortality due to H5N1 HPAIV was observed among mute and whooper swans as part of a rapid spread of this virus. In contrast to earlier reports, swans appeared to be highly susceptible and represented the mainly affected species. We report gross and histopathology and distribution of influenza virus antigen in mute and whooper swans that died after natural infection with H5N1 HPAIV. At necropsy, the most reliable lesions were multifocal hemorrhagic necrosis in the pancreas, pulmonary congestion and edema, and subepicardial hemorrhages. Major histologic lesions were acute pancreatic necrosis, multifocal necrotizing hepatitis, and lymphoplasmacytic encephalitis with neuronal necrosis. Adrenals displayed consistently scattered cortical and medullary necrosis. In spleen and Peyer's patches, mild lymphocyte necrosis was present. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas, adrenals, liver, and brain was strongly consistent with histologic lesions. In the brain, a large number of neurons and glial cells, especially Purkinje cells, showed immunostaining. Occasionally, ependymal cells of the spinal cord were also positive. In the lungs, influenza virus antigen was identified in a few endothelial cells but not within pneumocytes. The infection of the central nervous system supports the view that the neurotropism of H5N1 HPAIV leads to nervous disturbances with loss of orientation. More investigations are necessary to clarify the mechanisms of the final circulatory failure, lung edema, and rapid death of the swans. 相似文献
214.
Bread aroma is an important parameter for bread quality, and this review aims to provide an overview of aroma compounds identified in bread crumb and how these compounds are formed. More than 150 volatile compounds were identified in bread crumb, and they mainly originated from the fermentative activity of yeast, from oxidation of flour lipids, and to a lower extent from Maillard reactions. Of those volatile compounds, 45 compounds can be characterized as aroma compounds, because they most likely can be sensed when the bread is eaten because of their high odor activity values and flavor dilution factors. The influence of ingredients and mixing conditions on bread aroma has scarcely been investigated. The fermentation conditions (yeast level and strain as well as fermentation temperature and time) were found to significantly influence the aroma of bread crumb. Yeast level and strain mainly influence formation of compounds directly related to the fermentative activity of yeast, whereas fermentation temperature and time also influence formation of compounds from oxidation of flour lipids. 相似文献
215.
216.
Oelschlaegel S Gruner M Wang PN Boettcher A Koelling-Speer I Speer K 《Journal of agricultural and food chemistry》2012,60(29):7229-7237
Manuka honey from New Zealand is often considered to be a medicinal product of special value due to its high level of antimicrobial activity. Therefore, the distinct authentication of its botanical origin is of great importance. Aside from the common pollen analysis, it is in this respect particularly the analysis of the phenolic acids, flavonoids, and norisoprenoids that is described as useful. In the present study, numerous manuka honeys were analyzed by UPLC-PDA-MS/MS after solid-phase extraction and compared to other kinds of honey to define marker substances characteristic for manuka honeys. The PDA profiles obtained differed markedly from each other so that the individual honey samples could be assigned to three groups. For the honeys of group 1 the comparably high concentrations of 4-hydroxybenzoic acid, dehydrovomifoliol, and benzoic acid proved to be typical, whereas the profiles of group 2 showed high kojic acid and 2-methoxybenzoic acid intensities. The manuka honeys of group 3, on the other hand, yielded high amounts of syringic acid, 4-methoxyphenyllactic acid, and methyl syringate. Furthermore, the comprehensive comparison of manuka honeys to other unifloral honeys revealed that especially kojic acid, 5-methyl-3-furancarboxylic acid, leptosin, unedone, 2-methoxybenzoic acid, 4-methoxyphenyllactic acid, 3-hydroxy-1-(2-methoxyphenyl)penta-1,4-dione, and methyl syringate were useful for distinguishing manuka honeys from the other kinds of investigated honeys. Moreover, kojic acid, unedone, 5-methyl-3-furancarboxylic acid, 3-hydroxy-1-(2-methoxyphenyl)penta-1,4-dione, and lumichrome were identified in manuka honey for the first time. 相似文献
217.
Deres K Schröder CH Paessens A Goldmann S Hacker HJ Weber O Krämer T Niewöhner U Pleiss U Stoltefuss J Graef E Koletzki D Masantschek RN Reimann A Jaeger R Gross R Beckermann B Schlemmer KH Haebich D Rübsamen-Waigmann H 《Science (New York, N.Y.)》2003,299(5608):893-896
Chronic hepatitis B virus (HBV) infection is a major cause of liver disease. Only interferon-alpha and the nucleosidic inhibitors of the viral polymerase, 3TC and adefovir, are approved for therapy. However, these therapies are limited by the side effects of interferon and the substantial resistance of the virus to nucleosidic inhibitors. Potent new antiviral compounds suitable for monotherapy or combination therapy are highly desired. We describe non-nucleosidic inhibitors of HBV nucleocapsid maturation that possess in vitro and in vivo antiviral activity. These inhibitors have potential for future therapeutic regimens to combat chronic HBV infection. 相似文献
218.
D'Hondt S Jørgensen BB Miller DJ Batzke A Blake R Cragg BA Cypionka H Dickens GR Ferdelman T Hinrichs KU Holm NG Mitterer R Spivack A Wang G Bekins B Engelen B Ford K Gettemy G Rutherford SD Sass H Skilbeck CG Aiello IW Guèrin G House CH Inagaki F Meister P Naehr T Niitsuma S Parkes RJ Schippers A Smith DC Teske A Wiegel J Padilla CN Acosta JL 《Science (New York, N.Y.)》2004,306(5705):2216-2221
Diverse microbial communities and numerous energy-yielding activities occur in deeply buried sediments of the eastern Pacific Ocean. Distributions of metabolic activities often deviate from the standard model. Rates of activities, cell concentrations, and populations of cultured bacteria vary consistently from one subseafloor environment to another. Net rates of major activities principally rely on electron acceptors and electron donors from the photosynthetic surface world. At open-ocean sites, nitrate and oxygen are supplied to the deepest sedimentary communities through the underlying basaltic aquifer. In turn, these sedimentary communities may supply dissolved electron donors and nutrients to the underlying crustal biosphere. 相似文献
219.
Rak A Pylypenko O Durek T Watzke A Kushnir S Brunsveld L Waldmann H Goody RS Alexandrov K 《Science (New York, N.Y.)》2003,302(5645):646-650
Rab/Ypt guanosine triphosphatases (GTPases) represent a family of key membrane traffic regulators in eukaryotic cells whose function is governed by the guanosine diphosphate (GDP) dissociation inhibitor (RabGDI). Using a combination of chemical synthesis and protein engineering, we generated and crystallized the monoprenylated Ypt1:RabGDI complex. The structure of the complex was solved to 1.5 angstrom resolution and provides a structural basis for the ability of RabGDI to inhibit the release of nucleotide by Rab proteins. Isoprenoid binding requires a conformational change that opens a cavity in the hydrophobic core of its domain II. Analysis of the structure provides a molecular basis for understanding a RabGDI mutant that causes mental retardation in humans. 相似文献
220.
OBJECTIVE: To characterise misreporters of energy intake (EI) and energy expenditure (EE). DESIGN: Cross-sectional study, using a validated position and motion instrument, ActiReg, as the reference method to study misreporters of EI and of EE. EI was measured using a dietary record and EE using a physical activity questionnaire (PAQ). Misreporters were defined as subjects outside the 95% confidence limits of agreement between EI or EE reported/EE measured. SETTING: Free-living Danish volunteers. SUBJECTS: One hundred and thirty-eight volunteers aged between 20 and 59 years. RESULTS: Body mass index, smoking, 'try to eat healthily' and worries about weight were related to degree of under-reported EI. The percentage energy from added sugar was lowest (P < 0.001) and the percentage energy from protein (P < 0.001) highest in under-reporters compared with acceptable reporters. Subjects who reported being very physically active at work or in leisure time reported a higher EE than measured EE compared with less physically active subjects (P < 0.05). Likewise, subjects who regard themselves as fit or very fit reported a higher EE than subjects who regard themselves as moderately fit (P < 0.05). Possible over-reporters reported less time as very light activity (P = 0.007), more time as moderate activity (P = 0.01) and more time as vigorous activity (P = 0.02) than acceptable reporters. CONCLUSIONS: Under-reporting of EI should always be taken into consideration; however, only a few characteristics of under-reporters are consistent among studies. Misreporting of EI was more prevalent than misreporting of EE. The level of physical activity more than the time spent involved in various activities was misreported. 相似文献