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61.
Bacterial cellulose membranes (BCs) are becoming useful as a drug delivery system to the skin. However, there are very few reports on their application of plant substances to the skin. Komagataeibacter xylinus was used for the production of bacterial cellulose (BC). The BC containing 5% and 10% ethanolic extract of Epilobium angustifolium (FEE) (BC-5%FEE and BC-10%FEE, respectively) were prepared. Their mechanical, structural, and antioxidant properties, as well as phenolic acid content, were evaluated. The bioavailability of BC-FESs using mouse L929 fibroblasts as model cells was tested. Moreover, In Vitro penetration through the pigskin of the selected phenolic acids contained in FEE and their accumulation in the skin after topical application of BC-FEEs was examined. The BC-FEEs were characterized by antioxidant activity. The BC-5% FEE showed relatively low toxicity to healthy mouse fibroblasts. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), 3-hydroxybenzoic acid (3-HB), and caffeic acid (CA) found in FEE were also identified in the membranes. After topical application of the membranes to the pigskin penetration of some phenolic acid and other antioxidants through the skin as well as their accumulation in the skin was observed. The bacterial cellulose membrane loaded by plant extract may be an interesting solution for topical antioxidant delivery to the skin.  相似文献   
62.
Ultrasound is the most commonly used clinical imaging modality. However, in applications requiring cell‐labeling, the large size and short active lifetime of ultrasound contrast agents limit their longitudinal use. Here, 100 nm radius, clinically applicable, polymeric nanoparticles containing a liquid perfluorocarbon, which enhance ultrasound contrast during repeated ultrasound imaging over the course of at least 48 h, are described. The perfluorocarbon enables monitoring the nanoparticles with quantitative 19F magnetic resonance imaging, making these particles effective multimodal imaging agents. Unlike typical core–shell perfluorocarbon‐based ultrasound contrast agents, these nanoparticles have an atypical fractal internal structure. The nonvaporizing highly hydrophobic perfluorocarbon forms multiple cores within the polymeric matrix and is, surprisingly, hydrated with water, as determined from small‐angle neutron scattering and nuclear magnetic resonance spectroscopy. Finally, the nanoparticles are used to image therapeutic dendritic cells with ultrasound in vivo, as well as with 19F MRI and fluorescence imaging, demonstrating their potential for long‐term in vivo multimodal imaging.  相似文献   
63.
We performed a survey on the yield, quality, and chemical characteristics of virgin olive oils from two olive varieties in Croatian Istria: Frantoio and Ascolana tenera, on Cherry leafroll virus‐infected and virus‐noninfected trees and on two harvest dates. Free acidity, peroxide value, specific spectrophotometric absorptions at 232 and 270 nm, fatty acid composition, total phenols, o‐diphenols, oil color, and pigments were determined. Infected olives had lower oil yield and maturity index versus healthy ones. Oils from infected fruits had significant lower value of K232 and K270 and very elevated total phenols content compared to those obtained from healthy olives. Infected Frantoio gave a lower content of o‐diphenols than the healthy ones, which is in contrast to infected Ascolana that had higher values. The aim of this study is to determine the chemical changes in virgin olive oils from healthy and infected trees related to virus influence. According to our knowledge, this is the first survey on the possible influence of viruses on olive fruits, oil yield, and virgin olive oil quality. Practical applications : There are only few papers which analyze the influence of viruses on crops (especially influence on wine quality) and their effects on yield or other agronomic parameters. This work evaluates for the first time the impact of Cherry leafroll virus on the quality of virgin olive oil obtained from Frantoio and A. tenera varieties in terms of basic parameters related to the hydrolitic and oxidative status, content in antioxidant compounds, and in pigments as well as in fatty acid composition.  相似文献   
64.
The traditional query languages used in database management systems require precise and unambiguous queries only. Fuzzy querying was introduced to relax this rigidity and allow the user more natural information retrieval. In this article we suggest how to enrich fuzzy querying by the use of IF-sets. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 587–597, 2007.  相似文献   
65.
Recent investigations have suggested that novel food should be evaluated not only from the nutritional but also from the physiological point of view. Opioid peptides derived from milk belong to compounds whose physiological importance has not yet been fully recognized. The commercial Humana formula for newborns sold on the Polish market was assayed in the study. Four opioid peptides with agonistic and antagonistic activity were found in a peptide extract from the Humana formula and its pepsin–trypsin hydrolysate: β‐casomorphin‐5, casoxin C and 6 and lactoferroxin A. The opioid activity of the peptide extracts was determined by examining their influence on the motor activity of isolated rabbit intestine. In conclusion, it was suggested that the opioid activity of the formulas could be an additional indicator of their diversity. Copyright © 2007 Society of Chemical Industry  相似文献   
66.
67.
An automatic flow procedure based on a multicommuted flow analysis (MCFA) for the determination of the total polyphenolic content in food samples employing chemiluminescence (CL) as a detection technique is described. The concept of applying three-way solenoid valves in flow injection analysis was chosen in order to develop an environmentally friendly system which enables minimal consumption of reagents and waste generation. The method was based on the enhancing effect of polyphenolic antioxidants on CL of Mn(IV)–formaldehyde–hexametaphosphate system. The calibration graph obtained for standard solutions of gallic acid was linear in the range 5–150 μg L?1 with a detection limit of 1.5 μg L?1. The relative standard deviation for 20 measurements was between 1.1 and 2.4 %. The sampling rate was 60 determinations per hour. The proposed method was found to be selective to polyphenol detection and was successfully applied to the determination of the total polyphenol index in 27 diverse plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices and extracts of olive oil). A significant correlation between the total phenolic contentment determined by the MCFA-CL method and the total reducing capacity determined by Folin–Ciocalteu method and total antioxidant activity estimated by the DPPH method was observed.  相似文献   
68.
Aurachins are quinoline alkaloids isolated from the myxobacterium Stigmatella aurantiaca. They are substituted with an isoprenoid side chain and act as potent inhibitors in the electron transport chain. A biosynthetic gene cluster that contains at least five genes (auaA-auaE) has been identified for aurachin biosynthesis. In this study, auaA, the gene encoding a putative prenyltransferase of 326 amino acids, was cloned and overexpressed in Escherichia coli. Biochemical investigations showed that AuaA catalyzes the prenylation of 2-methyl-4-hydroxyquinoline in the presence of farnesyl diphosphate (FPP), thereby resulting in the formation of aurachin D. The hydroxyl group at position C4 of the quinoline ring is essential for an acceptance by AuaA; this was concluded by testing 18 quinoline derivatives or analogues with AuaA and FPP. (1) H NMR and HR-EI-MS analyses of six isolated enzyme products revealed the presence of a farnesyl moiety at position C3 of the quinoline ring. K(M) values of 43 and 270 μM were determined for FPP and 2-methyl-4-hydroxyquinoline, respectively. Like other known membrane-bound prenyltransferases, the reaction catalyzed by AuaA is dependent on the presence of metal ions such as Mg(2+) , Mn(2+) and Co(2+) , although no typical (N/D)DXXD binding motif was found in the sequence.  相似文献   
69.
The objective of our studies was to verify the potential health‐related, anti‐atherogenic potency of CLA isomers, fed to apolipoprotein E and LDL receptor double knockout mice (apoE/LDLR?/?), representing a reliable model of atherogenesis. Additionally, the effect of CLA isomers on liver steatosis was observed. In a “long experiment” (LONG), 2‐month‐old mice with no atherosclerosis were randomly assigned to three experimental groups and fed for the next 4 months. In a “short experiment” (SHORT), 4‐month‐old mice, with pre‐established atherosclerosis, were randomly assigned to three experimental groups and fed for the next 2 months. The experimental diets were: AIN‐93G (control), AIN‐93G + 0.5% trans‐10,cis‐12 CLA (t10,c12), and AIN‐93G + 0.5% cis9,trans‐11 CLA (c9,t11). In both experiments, c9,t11 CLA increased mice body weight. In mice fed t10,c12 CLA weight of liver was threefold (p<0.05) increased what was linked with hepatic steatosis observed in LONG and SHORT experiment. In LONG experiment, t10,c12 CLA significantly (p<0.05) increased plasma TAGs, whereas no such effect was observed in SHORT one. In mice receiving the CLA isomers the level of PPARα and SREBP‐1 mRNA in liver were significantly decreased. The expression of their target genes like ACO (PPARα) or FAS (SREBP‐1) were not changed. Only c9,t11 increased ACO level in LONG experiment. There were no isomer‐specific effects of CLA isomers on the area of atherosclerotic plaque. In conclusion, our results do not support the notion that CLA isomers supplementation to the diet has anti‐atherosclerotic effects. CLA isomers have no effect on atherosclerosis in apoE/LDLR?/? mice. Practical applications: CLAs have been shown to occur naturally in food. In the last 10 years, attempts have been made to enrich animal‐derived foods in CLA isomers through animal nutrition strategies. Indeed, these attempts resulted in production of functional food such as CLA‐enriched milk (butter and cheese), ruminant and non‐ruminant meat, as well as eggs. In addition to natural foodstuff, dietary CLA supplements can also contribute to CLA intake in humans. Commercial CLA preparations, fed to laboratory animals, showed several health‐related properties, including anti‐adipogenic, anti‐carcinogenic, anti‐atherogenic, and anti‐inflammatory effects. The underlying mechanisms of action, however, are only poorly understood. The major objective of our studies was to verify the potential health‐related, namely anti‐atherogenic potency of CLA isomers, fed to apoE/LDLR?/? mice, representing unique and reliable model of atherogenesis. Additionally, effect of CLA isomers on steatosis was observed.  相似文献   
70.
Radiant temperature has crucial significance in the evaluation of thermal conditions in a structure heated by high-temperature gas-fired radiant heaters. Its value can be influenced by various factors. The article presents the methods of calculating radiant temperature encountered in the literature and contains an analysis of the relation of radiant temperature and the mounting angle of the radiant heater as well as the relation of its power output and dimensions of the burning surface, based on the authors’ research. Formulae are given for calculation of radiant temperature and their correct usage is indicated. An example of distribution of radiant temperature in a hall heated by six gas-fired direct radiant heaters with the power output of 12 kW is presented.Examinations of gas-fired radiant heaters conducted so far provide insufficient information about creating thermal conditions at work stands heated by high temperature radiant heaters located in industrial spaces. Hence, the results presented here are of special importance as they refer to parameters characterizing the thermal comfort of people in large capacity halls.  相似文献   
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