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41.
Pérez-Gálvez A Rios JJ Mínguez-Mosquera MI 《Journal of agricultural and food chemistry》2005,53(12):4820-4826
The high-temperature treatment of paprika oleoresins (Capsicum annuum L.) modified the carotenoid profile, yielding several degradation products, which were analyzed by HPLC-APCI-MS. From the initial MS data, compounds were grouped in two sets. Set 1 grouped compounds with m/z 495, and set 2 included compounds with m/z 479, in both cases for the protonated molecular mass. Two compounds of the first set were tentatively identified as 9,10,11,12,13,14,19,20-octanor-capsorubin (compound II) and 9,10,11,12,13,14,19,20-octanor-5,6-epoxide-capsanthin (compound IV), after isolation by semipreparative HPLC and analysis by EI-MS. Compounds VII, VIII, and IX from set 2 were assigned as 9,10,11,12,13,14,19,20-octanor-capsanthin and isomers, respectively. As these compounds were the major products formed in the thermal process, it was possible to apply derivatization techniques (hydrogenation and silylation) to analyze them by EI-MS, before and after chemical derivatization. Taking into account structures of the degradation products, the cyclization of polyolefins could be considered as the general reaction pathway in thermally induced reactions, yielding in the present study xylene as byproduct and the corresponding nor-carotenoids. 相似文献
42.
Mueller CA Broz P Müller SA Ringler P Erne-Brand F Sorg I Kuhn M Engel A Cornelis GR 《Science (New York, N.Y.)》2005,310(5748):674-676
Many pathogenic bacteria use injectisomes to deliver effector proteins into host cells through type III secretion. Injectisomes consist of a basal body embedded in the bacterial membranes and a needle. In Yersinia, translocation of effectors requires the YopB and YopD proteins, which form a pore in the target cell membrane, and the LcrV protein, which assists the assembly of the pore. Here we report that LcrV forms a distinct structure at the tip of the needle, the tip complex. This unique localization of LcrV may explain its crucial role in the translocation process and its efficacy as the main protective antigen against plague. 相似文献
43.
Two types of consolidated memory have been described in Drosophila, anesthesia-resistant memory (ARM), a shorter-lived form, and stabilized long-term memory (LTM). Until now, it has been thought that ARM and LTM coexist. On the contrary, we show that LTM formation leads to the extinction of ARM. Flies devoid of mushroom body vertical lobes cannot form LTM, but spaced conditioning can still erase their ARM, resulting in a remarkable situation: The more these flies are trained, the less they remember. We propose that ARM acts as a gating mechanism that ensures that LTM is formed only after repetitive and spaced training. 相似文献
44.
G protein signalling involved in host recognition and mycoparasitismrelated chitinase expression in Trichoderma atroviride 下载免费PDF全文
Susanne Zeilinger Barbara Reithner Kurt Brunner Valeria Scala Isabel Peiβl Matteo Lorito Robert L Mach 《浙江大学学报(农业与生命科学版)》2004,30(4):448-448
Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e.g. lectins or other ligands such as low molecular weight components released from the host's cell wall) and host attack is ac… 相似文献
45.
46.
Ediane Batista da Silva Bruna Daniella de Souza Silva Jerônimo Rafael Ruiz Leon André Kipnis Isabel K.F. de Miranda Santos Ana Paula Junqueira-Kipnis 《Veterinary journal (London, England : 1997)》2011,187(2):276-278
This study evaluated the Mycobacterium tuberculosis protein antigen MPT-51, the trimeric antigen 85 (Ag85) complex, and Bacillus Calmette-Guérin (BCG) in an indirect ELISA to diagnose bovine tuberculosis (TB) from serum samples. Serum was collected from 208 intra-dermal tuberculin test (ITT)-positive and 54 ITT-negative animals from a region where bovine TB is endemic. Using the Ag85 and BCG antigens, the indirect ELISA was able to discriminate ITT-positive from ITT-negative animals. This level of discrimination was not achieved when using the MPT-51 antigen. The highest sensitivity (Se) and specificity (Sp) of the test was found when BCG was used (Se, 82%; Sp, 91%). Further work in different epidemiological settings and with larger numbers of animals will be required to validate these findings. 相似文献
47.
Aurelia Bonet Nieves Diaz-Caneja Isabel Gutierrez Antonio Martínez Eugenio Villar 《Water, air, and soil pollution》1988,38(1-2):181-188
A study was carried out on the pH values obtained from bulk (wet and dry) precipitation samples collected simultaneously in two cities in Cantabria (Spain), Santander and Torrelavega over a period of a year. It was observed that the annual weighted average values for the pH of precipitation, 4.42 and 4.21, respectively, differ significantly although the difference is less than that existing between their pollution levels. The difference is greater when total annual H+ depositions are compared. The study also demonstrated the strong influence of long-range transport effect on acidity and to a lesser degree the effect of mid-range transport. 相似文献
48.
Gallardo-Guerrero L Hornero-Méndez D Mínguez-Mosquera MI 《Journal of agricultural and food chemistry》2002,50(23):6746-6751
The pectic and pigment compositions and Ca and Cu contents of the alcohol-insoluble solid (AIS) residues were determined in cv. Gordal olives treated with NaOH solution and kept at different constant pH values (3.5-6.5). The same controls were made in table olives presenting green staining alteration. The ratio between the various pectin fractions of the more acid pH experiment samples remained similar in fruits not showing green staining. In altered fruits, the protopectin fraction was lower, and the calcium pectate or EDTA soluble pectins were higher. Regarding the presence of Ca and Cu in the AIS, it was observed that, whereas Ca levels fell at the most acid pH values, those of Cu increased. The concentration of Ca was higher in the AIS of altered olives than in nonaltered ones. The same trend was seen for the zone with or without green staining of an altered fruit. In the case of Cu, the relationship was the opposite: a decrease in the levels of AIS Cu in fruits and zones of fruits with green staining. This result was correlated with the highest concentration of Cu-chlorophyll complexes found in such samples and suggested that pectins might act as a reservoir of Cu involved in the alteration. 相似文献
49.
50.
Effect of salicylic acid treatment on tomato plant physiology and tolerance to potato virus X infection 总被引:1,自引:0,他引:1
Tania Falcioni Juan Pedro Ferrio Ana Isabel del Cueto Jordi Giné María Ángeles Achón Vicente Medina 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(2):331-345
Salicylic acid (SA) is an inducer of systemic acquired resistance (SAR) and could be a potential candidate in the control of plant virus diseases. In this study we assayed under controlled conditions the potential effect of three doses of exogenous SA treatment on tomato plants infected with Potato virus X (PVX) and measured their effects on: different physiological parameters (gas exchange, stable isotopes, chlorophyll content), the activation of secondary metabolism, viral accumulation and induction of the expression of pathogenesis-related proteins (PRs) such as ß-1, 3-glucanase (PR2) and chitinase (PR3). SA treatment increased the expression of PR2, the activity of phenylalanine ammonia lyase (PAL) and the concentration of antioxidant compounds at 7 days post-treatment. Earlier expression of PR3 compared to PR2 was observed. SA treatment delayed the detection of PVX by ELISA in uninoculated leaves of mechanically infected tomato plants. Although the effect of PVX infection on physiological parameters was weak, moderate SA treatments showed enhanced photosynthesis, particularly for infected plants. The results obtained confirm that SA promotes major changes in the induction of resistance in tomato plants and suggest that treatment with exogenous SA could be considered to reduce the infections caused by PVX. 相似文献