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排序方式: 共有292条查询结果,搜索用时 15 毫秒
21.
The volatiles produced by leaves and fruits of Olea europaea cv. Olivastra Seggianese have been analyzed in two different phenological stages. Furthermore, the volatiles of the virgin olive oil obtained from ripe fruits has been characterized. The volatiles were sampled by means of two different techniques: hydrodistillation and SPME. Differences were observed between the two different collection times, the different organs, and sampling techniques. The major constituents were often aldehydes, particularly (E)-2-hexenal (9.8-48.0%); however, also many terpenoids have been identified, mainly (E,E)-alpha-farnesene (0.2-27.0%), linalool (0-3.6%), beta-caryophyllene (0-8.1%), and valencene (0-2.5%). This is the first investigation on this cultivar. 相似文献
22.
Characterization of the anthocyanin fraction of sicilian blood orange juice by micro-HPLC-ESI/MS 总被引:5,自引:0,他引:5
Dugo P Mondello L Morabito D Dugo G 《Journal of agricultural and food chemistry》2003,51(5):1173-1176
Anthocyanins of red orange juices were analyzed by micro-HPLC coupled on-line with an MS detector equipped with an ESI source. The use of microcolumn HPLC greatly enhanced detection performance, allowing direct identification of the anthocyanins present in the orange juices. The use of a soft ionization technique allows detection of the molecular ions of the aglycons. Eight components were identified, five of them for the first time in red orange juice. Three additional anthocyanins were detected, of which only the aglycon was identified. 相似文献
23.
Keller LP Bajt S Baratta GA Borg J Bradley JP Brownlee DE Busemann H Brucato JR Burchell M Colangeli L d'Hendecourt L Djouadi Z Ferrini G Flynn G Franchi IA Fries M Grady MM Graham GA Grossemy F Kearsley A Matrajt G Nakamura-Messenger K Mennella V Nittler L Palumbo ME Stadermann FJ Tsou P Rotundi A Sandford SA Snead C Steele A Wooden D Zolensky M 《Science (New York, N.Y.)》2006,314(5806):1728-1731
Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust. 相似文献
24.
Rita?MusettiEmail author Luigi?Sanità?di Toppi Marta?Martini Francesca?Ferrini Alberto?Loschi Maria?Augusta?Favali Ruggero?Osler 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(1):53-61
Hydrogen peroxide (H2O2) localization and roles of peroxidases, malondialdehyde and reduced glutathione were compared in leaves of apricot (Prunus armeniaca) plants asymptomatic, European Stone Fruits Yellows (ESFY)-symptomatic and recovered. Nested PCR analysis revealed that Candidatus Phytoplasma prunorum, is present in asymptomatic, symptomatic and recovered apricot trees, confirming previous observations on this species, in which recovery does not seem to be related to the disappearance of phytoplasma from the plant.H2O2was detected cytochemically by its reaction with cerium chloride, which produces electron-dense deposits of cerium perhydroxides. H2O2was present in the plasmalemma of the phloem cells of recovered apricot plant leaves, but not in the asymptomatic or symptomatic material. Furthermore, by labelling apricot leaf tissues with diaminobenzidine DAB, no differences were found in the localization of peroxidases.Protein content in asymptomatic, symptomatic and recovered leaves was not significantly different from one another. In contrast, guaiacol peroxidase activity had the following trend: symptomatic > recovered > asymptomatic, whereas reduced glutathione content followed the opposite trend: asymptomatic > recovered > symptomatic. Moreover, no differences were observed in malondialdehyde concentrations between asymptomatic, symptomatic and recovered leaves. The overall results suggest that H2O2 and related metabolites and enzymes appear to be involved in lessening both pathogen virulence and disease symptom expression in ESFY-infected apricot plants. 相似文献
25.
Gian Luigi Stracciari 《Veterinary research communications》1979,3(1):57-63
The reactivity of bovine foetal intestine to some acetylcholine derivatives is compared with the response to acetylcholine. Qualitatively similar responses are observed between the bovine intestine after mid-foetal life and intestinal tissue from adult animals. A lower reactivity of the foetal preparations could be partly explained by the existence of different levels of cholinesterase in the tissues at different times during embryogenesis. Foetal intestine reacts with different intensity to the cholinergic agents tested.
Kurzfassung Man studiert die Reaktion des Fötusdarmes von Rind auf einige Azethylcholin Derivate im Vergleich mit Azethylcholin. Das Studium erklärt dass der nach der Mitte des embryonalen Lebens Rinddarm und der von erwachsenen Tieren Darm, auf gleiche Weise sich betragen. Eine kleinere Reaktion der Fötuspräparate möchte mit der Anwesenheit von verschiedenen Cholinesterase Konzentrationen in den Geweben während der embryonalen Entwicklung, teilweise erklärt werden. Der Fötusdarm reagiert auf die cholinergischen geprüften Mittel mit verschiedener Intensität.
Resume L'A. étude la réactivité de l'intestin foetal de boeuf à quelques dérivés de l'acétylcholine en comparaison du médiateur cholinergique. Qualitativement des réponses similaires ont été observées dans l'intestin aprés la moitié de la vie foetale et celui des animaux adults. La plus petite réactivité des préparations foetales pourrait être expliquée partiellement par l'existence de concentrations différentes de cholinestérase tissulaire dans de différentes périodes du dévelopement embryonnaire. L'intestin foetal réagit avec diverse intensité aux médicaments cholinergiques éxaminés.
Riassunto L'A. studia la reattività dell'intestino fetale bovino ad alcuni derivati dell'acetilcolina paragonandola con la risposta evocata dal mediatore colinergico. Qualitativamente vengono riscontrate risposte simili tra l'intestino bovino proveniente da feti che hanno superato la metà della vita embrionale e quello di animali adulti. La minore reattività dei preparati fetali potrebbe essere parzialmente interpretata dal reperimento di differenti concentrazioni di colinesterasi tessutali a tempi diversi di sviluppo embrionale. L'intestino fetale reagisce con diversa intensità agli agenti colinergici saggiati.相似文献
26.
Sandford SA Aléon J Alexander CM Araki T Bajt S Baratta GA Borg J Bradley JP Brownlee DE Brucato JR Burchell MJ Busemann H Butterworth A Clemett SJ Cody G Colangeli L Cooper G D'Hendecourt L Djouadi Z Dworkin JP Ferrini G Fleckenstein H Flynn GJ Franchi IA Fries M Gilles MK Glavin DP Gounelle M Grossemy F Jacobsen C Keller LP Kilcoyne AL Leitner J Matrajt G Meibom A Mennella V Mostefaoui S Nittler LR Palumbo ME Papanastassiou DA Robert F Rotundi A Snead CJ Spencer MK Stadermann FJ Steele A 《Science (New York, N.Y.)》2006,314(5806):1720-1724
Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples. 相似文献
27.
Giovanna Romano Emiliano Manzo Gian Luigi Russo Giuliana d’Ippolito Adele Cutignano Maria Russo Angelo Fontana 《Marine drugs》2013,11(11):4527-4543
Oxylipins are a large and diverse family of fatty acid derivatives exhibiting different levels of oxidation of the carbon chain. They are involved in many biological functions in mammals, plants and diatoms. In this last group of organisms, they are suggested to play a role in the reproductive failure of copepod predators, showing clear pro-apoptotic effects on newborn nauplii. In this work, these compounds were tested for the ability to induce mitotic arrest in sea urchin embryos. We show for the first time that oxylipins have an increased efficacy in their corresponding methylated form. Natural oxylipins were also used as an inspiration for the rational design and synthesis of stable chemical analogs with apoptotic activity against tumor cell lines. This approach led to the synthesis of the linear C15-ketol (22) that was shown to induce apoptosis in human leukemia U-937 cells. These results are proof of the concept of the use of eco-physiological considerations as a platform to guide the search for novel drug candidates. 相似文献
28.
Flora Alfano Maria Cammareri Angela Errico Luigi Frusciante Clara Conicella 《American Journal of Potato Research》1999,76(5):281-285
Pollen stainability over two years and microsporogenesis were investigated in seven dihaploids extracted fromSolanum tuberosum tetraploids (AVRDC-1287.19, Conchita, Merrimack and W231). Two dihaploids proved to be male-sterile and male gamete abortion is likely to be post-meiotic because a regular meiosis occurred. The other dihaploids proved to be partially male-fertile and 2n pollen producers, as well. Almost all clones showed predominantly the formation of parallel spindles. Correlations estimated between the observed abnormalities in spindle orientation and the meiotic products evidenced a high correlation between parallel/fused spindles and dyads. The dihaploids were also used as parents in crosses with tetraploids. One berry with 44 seeds was obtained from dihaploid AVI 24 used as pollen parent in 4x × 2x crosses. After 2x × 4x crosses, three dihaploids including the two male-sterile were found to be 2n egg producers. The formation of 2n gametes inS. tuberosum dihaploids is discussed in relation to a direct use of dihaploids in sexual polyploidization schemes to combine useful traits in a superior genotype at 4x level. 相似文献
29.
Claudio Caruso Andrea Gustinelli Paolo Pastorino Pier Luigi Acutis Riccardo Prato Loretta Masoero Simone Peletto Maria Letizia Fioravanti Marino Prearo 《Journal of fish diseases》2019,42(5):773-776
This work reports a mortality outbreak, occurred in 2015 and affecting juveniles of European perch (Perca fluviatilis L.) farmed in Italy. Perch rhabdovirus (PRV) was detected by viral isolation and biomolecular investigations. Phylogenetic analysis clustered our isolate into genogroup B, which also includes PRV isolates from Perca fluviatilis identified in France (2004–2009); diagnostic investigations also revealed opportunistic bacteria (Aeromonas hydrophila) and parasites (Chilodonella piscicola). Since, occasionally, PRV has been reported in the natural environment, which is often a source of eggs and broodstock for farms, it could be possible that both similar France and Italian isolate were imported from a same place elsewhere and have a common origin. Improving biosecurity measures (batch control) and disinfection of egg strings with an iodine‐based solution helps prevent apparent vertical transmission of PRV. 相似文献
30.