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951.
Olívia R. Pereira Artur M.S. SilvaMaria R.M. Domingues Susana M. Cardoso 《Food chemistry》2012,131(2):652-659
The phenolic composition of the ethanolic extract obtained from the flowers of the medicinal plant Cytisus multiflorus has been elucidated by high performance liquid chromatography, electrospray mass spectrometry and nuclear magnetic resonance analysis. The extract was mainly composed of flavones, including the common chrysin, orientin, luteolin-5-O-glucoside, luteolin-7-O-glucoside, apigenin and apigenin-7-O-glucoside, which appeared as minor components. The major flavone in the extract was chrysin-7-O-β-d-glucopyranoside, and it also contained moderate amounts of a dihydroxyflavone isomer of chrysin, as well as of 2″-O-pentosyl-6-C-hexosyl-luteolin, 2″-O-pentosyl-8-C-hexosyl-luteolin and 6″-O-(3-hydroxy-3-methylglutaroyl)-2″-O-pentosyl-C-hexosyl-apigenin, which are not commonly found in the Fabaceae family. Other novel phenolic compounds found in the ethanolic extract of C. multiflorus comprised the flavones 2″-O-pentosyl-6-C-hexosyl-apigenin, 2″-O-pentosyl-8-C-hexosyl-apigenin and 6″-O-(3-hydroxy-3-methylglutaroyl)-2″-O-pentosyl-C-hexosyl-luteolin. The assessment of the biological activities of the main compounds of this extract are now keen, in order to determine their relevance in the beneficial properties of the plant. 相似文献
952.
Martin D’Agostino Nigel Cook Ilaria Di Bartolo Franco M. Ruggeri Alessandra Berto Francesca Martelli Malcolm Banks Petra Vasickova Petr Kralik Ivo Pavlik Petros Kokkinos Apostolos Vantarakis Kirsi S?derberg Leena Maunula Katharina Verhaelen Saskia Rutjes Ana Maria de Roda Husman Renate Hakze Wim Van der Poel Agnieszka Kaupke Iwona Kozyra Artur Rze?utka Jasna Prodanov Sava Lazic Tamas Petrovic Anna Carratala Rosina Gironés Marta Diez-Valcarce Marta Hernandez David Rodriguez-Lazaro 《Food Analytical Methods》2012,5(1):1-7
The qualitative performance characteristics of a qPCR-based method to detect human adenoviruses in raspberries were determined through a collaborative trial involving 11 European laboratories. The method incorporated a sample process control (murine norovirus) and an internal amplification control. Trial sensitivity or correct identification of 25-g raspberry samples artificially contaminated with between 5?×?102 and 5?×?104?PFU was 98.5%; the accordance and concordance were 97.0%. The positive predictive value was 94.2%. The trial specificity or percentage correct identification of non-artificially contaminated samples was 69.7%; the accordance was 80.0% and the concordance was 61.7%. The negative predictive value was 100%. Application of a method for the detection of human adenoviruses in food samples could be useful for routine monitoring for food safety management. It would help to determine if a route of contamination exists from human source to food supply chain which pathogenic viruses such as norovirus and hepatitis A virus could follow. 相似文献
953.
Luís Batista Sara Monteiro Virgílio B. Loureiro Artur R. Teixeira Ricardo B. Ferreira 《Food chemistry》2010
The effect on the wine protein haze potential of five organic acids commonly encountered in wines (l(+)-tartaric, l(−)-malic, citric, succinic and gluconic acids) was assessed. All five acids, tested at 20 mM, reduced dramatically the haze potential of proteins, either in wine or dissolved in water, throughout the range of pH values typical of wines (i.e., from 2.8 through 3.8). Subtle differences among the acid effects did not correlate with the number of their carboxyl groups, but were attributed to electrostatic interactions that depend upon the acid pKa values, the protein pI values and the medium pH. These results invalidate or question the validity of all experiments on wine proteins involving wine model solutions containing organic acids. Overall, the results obtained in the present work clearly indicate that organic acids with a common occurrence in wines exhibit a stabilising effect upon the haze potential of the wine proteins. 相似文献
954.
Justyna Cybulska Els Vanstreels Quang Tri Ho Christophe M. Courtin Valerie Van Craeyveld Bart Nicolaï Artur Zdunek Krystyna Konstankiewicz 《Journal of food engineering》2010
Artificial plant cell walls were produced from bacterial cellulose and cell wall constituents. The artificial cell walls were stored at low, medium and high relative humidity, and then subjected to micro-mechanical tests. From chemical composition and microstructure analysis it was found that, among all artificial cell wall materials produced, the most representative analogue of natural apple cell wall was based on bacterial cellulose supplemented with xyloglucan and pectin. Uniaxial tensile tests revealed that the different cell wall materials differed in their mechanical properties; increasing the humidity during storage resulted in a decrease in the value of the secant modulus. The cell wall model material obtained may be used for the simulation of the effect of external factors on the physical and chemical properties of cell walls. 相似文献
955.
Artur Zdunek Justyna Cybulska Dorota Konopacka Krzysztof Rutkowski 《Journal of food engineering》2010
A new contact acoustic emission detector (CAED) was developed for the instrumental texture evaluation of apples. The goal of this work was to determine the relations between instrumental parameters and sensory texture attributes, and to develop calibration models for prediction of the sensory texture of apples with CAED. Seven apple cultivars were used for the construction and validation of the models. CAED is particularly useful for evaluation of sensory crispness, crunchiness and hardness. There is also a significant correlation of acoustic emission counts with juiciness, mealiness and overall texture. Validation of the models indicates better prediction of these sensory attributes by total acoustic emission counts than prediction by puncture firmness in terms of variance explained, root-mean-square of a model prediction, and bias. 相似文献
956.
Voss S Welte S Fotin-Mleczek M Fischer R Ulmer AJ Jung G Wiesmüller KH Brock R 《Chembiochem : a European journal of chemical biology》2006,7(2):275-286
The interaction of lipopolysaccharide with CD14 plays a key role in signaling that activates an early defense against pathogens but also contributes to the development of sepsis and septic shock. Here we have mapped the entire 356-amino-acid protein with synthetic 20-amino-acid peptides and have identified a new lipopolysaccharide-binding domain with a strong LPS-neutralizing activity. Moreover, analysis of the structure-activity relationship of this peptide, which corresponds to amino acids 81-100 of human CD14, revealed that leucines 87, 91, and 94 are essential for these activities. The functional relevance of these residues was confirmed by cellular expression of mutant CD14 proteins that are no longer able to bind LPS. Furthermore, the peptide provided a basis for the generation of highly soluble analogues with stronger lipopolysaccharide-neutralizing activity. 相似文献
957.
Presley SM Rainwater TR Austin GP Platt SG Zak JC Cobb GP Marsland EJ Tian K Zhang B Anderson TA Cox SB Abel MT Leftwich BD Huddleston JR Jeter RM Kendall RJ 《Environmental science & technology》2006,40(2):468-474
Storm surge associated with Hurricane Katrina and the breach of levees protecting New Orleans, Louisiana allowed floodwaters from Lake Pontchartrain to inundate 80% of the city. Environmental samples were collected during September 16-18, 2005 to determine immediate human and wildlife health hazards from pathogens and toxicants in the floodwaters. Baseline information on potential long-term environmental damage resulting from contaminants in water and sediments pumped into Lake Pontchartrain was also collected. Concentrations of aldrin, arsenic, lead, and seven semivolatile organic compounds in sediments/soils exceeded one or more United States Environmental Protection Agency (USEPA) thresholds for human health soil screening levels and high priority bright line screening levels. High numbers of Aeromonas spp., pathogenic Vibrio spp., and other coliform bacteria were found in floodwater samples. Alligator and snake tissues did not contain excessive toxicant concentrations. Initial findings suggest numerous environmental contaminants are present in New Orleans and support the need for further evaluation of the extent of those threats. 相似文献
958.
De Lamo-Castellví S Capellas M Roig-Sagués AX López-Pedemonte T Hernández-Herrero MM Guamis B 《Journal of food protection》2006,69(12):2856-2864
The aim of this research was to study high hydrostatic pressure inactivation of two strains of Escherichia coli (E. coli O59:H21 [CECT 405] and E. coli O157:H7 [CECT 5947]) inoculated in washed-curd model cheese elaborated with and without starter and the ability of these strains for survival, recovery, and growth. Samples were treated at 300, 400, and 500 MPa for 10 min at 20 degrees C and analyzed after the treatment and after 1, 7, and 15 days of storage at 8 degrees C to study the behavior of Escherichia populations. Cheeses elaborated with starter showed the maximum lethality at 400 and 500 MPa, and no significant differences in the baroresistant behavior of either strains were detected, except for E. coli O157:H7 at 400 MPa in cell counts obtained with thin agar layer method medium, where the decrease value was significantly lower. In cheese elaborated without starter, the highest decrease value was observed at 500 MPa, except for E. coli O59:H21 in cell counts obtained with selective culture medium, where the highest decrease value was also found at 400 MPa. The ability to repair and grow was not observed in model cheese elaborated with starter, as cell counts of treated samples decreased after 15 days of storage at 8 degrees C. By contrast, in cheese elaborated without starter, all pressurized samples showed the trend to repair and grow during the storage period in both strains. These results suggest that the presence of starter and low pH values are the main factors that control the ability of Escherichia strains inoculated in this type of cheese and treated by high hydrostatic pressure to recover and grow. 相似文献
959.
Marcin Wierzchowski Daniel Ziental Dawid aewski Artur Korzanski Agnieszka Gielara-Korzanska Ewa Tykarska Jolanta Dlugaszewska Lukasz Sobotta 《International journal of molecular sciences》2022,23(11)
Newly developed tetra- and octasubstituted methimazole-phthalocyanine conjugates as potential photosensitizers have been obtained. Synthesized intermediates and final products were characterized by the MALD-TOF technique and various NMR techniques, including 2D methods. Single-crystal X-ray diffraction was used to determine the crystal structures of dinitriles. The studied phthalocyanines revealed two typical absorption bands—the Soret band and the Q band. The most intense fluorescence was observed for octasubstituted magnesium(II) phthalocyanine in DMF (ΦFL = 0.022). The best singlet oxygen generators were octasubstituted magnesium(II) and zinc(II) phthalocyanines (Φ∆ 0.56 and 0.81, respectively). The studied compounds presented quantum yields of photodegradation at the level between 10−5 and 10−6. Due to their low solubility in a water environment, the liposomal formulations were prepared. Within the studied group, octasubstituted zinc(II) phthalocyanine at the concentration of 100 µM activated with red light showed the highest antibacterial activity against S. aureus equal to a 5.68 log reduction of bacterial growth. 相似文献
960.
Artur Łoza Lyudmila Mihaylova David Bull Nishan Canagarajah 《Machine Vision and Applications》2009,20(2):71-83
This paper addresses the problem of object tracking in video sequences for surveillance applications by using a recently proposed
structural similarity-based image distance measure. Multimodality surveillance videos pose specific challenges to tracking
algorithms, due to, for example, low or variable light conditions and the presence of spurious or camouflaged objects. These
factors often cause undesired luminance and contrast variations in videos produced by infrared sensors (due to varying thermal
conditions) and visible sensors (e.g., the object entering shadowy areas). Commonly used colour and edge histogram-based trackers
often fail in such conditions. In contrast, the structural similarity measure reflects the distance between two video frames
by jointly comparing their luminance, contrast and spatial characteristics and is sensitive to relative rather than absolute
changes in the video frame. In this work, we show that the performance of a particle filter tracker is improved significantly
when the structural similarity-based distance is applied instead of the conventional Bhattacharyya histogram-based distance.
Extensive evaluation of the proposed algorithm is presented together with comparisons with colour, edge and mean-shift trackers
using real-world surveillance video sequences from multimodal (infrared and visible) cameras. 相似文献