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91.
Nanocrystalline titanium dioxide (nanoTiO2) has been reported to generate reactive oxygen species (ROS) under UV illumination. In our studies, changes in mechanical properties of human skin fibroblasts, exposed to the oxidative stress induced in the presence of nanoTiO2 and UV light, were studied using atomic force microscopy (AFM). The exposure of cells to the action of ROS was performed at low TiO2 concentration (4 microg/mL) and under illumination with low-intensity UVA (8 and 20 mW/cm2) or UVC (0.1 mW/ cm2). AFM measurements of the cell stiffness were carried out immediately after exposure of cells to the oxidative stress. The data suggest that under illumination with low-intensity UVA nanoTiO2 generates ROS, which, in turn, damage cellular and subcellular structures. This process was detected by AFM as a marked drop in the cellular stiffness of ca. 30-75%, which occurred rapidly, in the time frame of 1 min. The photo-oxidative stress inducing the decrease of cell stiffness was cancelled in the presence of a well-established antioxidant, beta-carotene. The results highlight the sensitivity of AFM to detect early changes in mechanical properties of cells exposed to oxidative stress.  相似文献   
92.
Food Science and Biotechnology - The objective of this study was to obtain the in vitro cultures of Boletus badius under controlled conditions and investigate the release of indole compounds and...  相似文献   
93.
The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.  相似文献   
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A multiresidue method for the analysis of over 140 multiclass pesticides in fruiting vegetables, based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation procedure followed by gas chromatography-tandem mass spectrometry (GC-MS/MS), was established. In the validation study, the overall recoveries from spiked samples were 102?±?7, 95?±?7, and 95?±?7 % with RSD values of 7?±?3, 7?±?4, and 7?±?3 % at the spiking levels of 0.01, 0.05, and 0.5 mg kg?1, respectively, demonstrating fitness for purpose of the method. The limit of quantification (LOQ) was 0.01 mg kg?1 for more than 90 % of the target compounds. The analysis of over 300 samples of tomatoes, sweet peppers, and cucumbers was carried out in 2006–2014. Of these samples, 52 % contained pesticide residues but the results of the assessment of dietary exposure supported the conclusion that the presence of pesticide residues was unlikely to have a negative effect on the health of consumers. Although some of the pesticides detected in years 2006–2009 are no longer approved in the European Union member countries (namely endosulfan, oxadixyl, procymidone, propargite, and tolylfluanid), the consumer dietary exposure was low and did not exceed 12 % of the acceptable daily intake (ADI) considering both adults’ and children’s diet. Regarding short-term exposure (acute), in only one case of procymidone in sweet pepper, the acute reference dose (ARfD) for children was exceeded by 139.6 % of the ARfD.  相似文献   
98.
Frozen yogurt is a type of dairy product that is considered to be a more healthful alternative to conventional ice cream due to its lower fat content and the presence of viable lactic acid bacteria. Lactose-free products are a growing trend in the dairy industry, and lactose-free yogurts and ice creams can both be found on the market. However, lactose-free frozen yogurt has not yet reached the market. In this study, we aimed to investigate the effect of adding κ-carrageenan (0.05, 0.1, and 0.15%) and corn starch (1, 2, and 3%) on acidity, texture, viscosity, overrun, melting properties, color attributes, and sensory characteristics of lactose-free frozen yogurts. Lactose was reduced by enzymatic hydrolysis during the fermentation process. The effectiveness of the hydrolysis was measured by HPLC, and lactose was reduced to 0.05% after 80 min of incubation with the enzyme. The addition of stabilizers did not change overrun and melting properties of frozen yogurt, but it did affect pH, titratable acidity, and color parameters. The product with 0.15% κ-carrageenan had the highest hardness and stickiness values. Moreover, κ-carrageenan had a positive effect on sensory attractiveness of lactose-free frozen yogurt, and it reduced the coarse texture in comparison with the control without stabilizers. A lactose-free frozen yogurt with good quality and nutritional characteristics was produced, particularly with the use of κ-carrageenan as stabilizer.  相似文献   
99.
Tryptophan (Trp) is an amino acid and an essential component of the human diet. It plays a crucial role in many metabolic functions. Clinicians can use Trp levels in the course of diagnosing various metabolic disorders and the symptoms associated with those diseases. Furthermore, supplementation with this amino acid is considered in the treatment of depression and sleep disorders, mainly due to the Trp relationship with the synthesis of serotonin (5-HT) and melatonin. It is also used in helping to resolve cognitive disorders, anxiety, or neurodegenerative diseases. Reduced secretion of serotonin is associated with autism spectrum disorder, obesity, anorexia and bulimia nervosa, and other diseases presenting peripherals symptoms. The literature strongly suggests that Trp has a significant role in the correct functionality of the brain-gut axis and immunology. This information leads to the consideration of Trp as an essential dietary component due to its role in the serotonin pathway. A reduced availability of Trp in diet and nutraceutical supplementation should be considered with greater concern than one might expect. This paper constitutes a review of the more salient aspects gleaned from the current knowledge base about the role of Trp in diseases, associated nutritional disorders, and food science, in general.  相似文献   
100.
Over the last decade, dendritic structures including hyperbranched polymers, dendrigrafts, dendrons, and dendrimers due to their distinct structural design such as highly branched structure and a large number of reactive end groups have received considerable attention. Among various kind of dendrimer, particularly amine-terminated dendritic materials like polyamidoamine (PAMAM), polypropylene imine (PPI), and polyethylene imine (PEI) have been introduced as the potential candidates in a wide range of areas, particularly in the field of textiles engineering. Hence, this review provides an introduction of amine-terminated dendritic polymers and new potential applications of them in textiles engineering such as improvement of dyeability, salt-free dyeability, antimicrobial activity, long-lasting fragrant fabric, anti-ultraviolet property, drug delivery through fabric, flame retardancy, and wastewater treatment. Regarding the complex synthesis of dendrimers which makes them expensive products, application of amine-terminated hyperbranched polymers provides affordable dendritic polymers to create novel features.  相似文献   
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