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Radiation induced molecular changes in macromolecular components of hazelnut tissues were investigated by mid-Fourier transform infrared (FTIR) spectroscopy. Irradiation dose of 1.5 kGy (low) and 10 kGy (high) were applied. The changes in frequency, signal intensity and intensity ratio of IR bands revealed that the unsaturated lipid concentration increased for low dose treated samples whereas it decreased and peroxidation appeared at high dose treatment. The low dose irradiation treatment, slightly increased the total lipid content whereas it dramatically decreased for high dose treatment. A slight increase in the lipid to protein ratio was observed for low dose treatment, whilst this ratio significantly decreased for high dose treatment. In addition, the high dose γ-irradiation caused alterations in the structure of hazelnut proteins, as cross-linking and aggregation occured in protein molecules. These results indicate that FTIR spectroscopy can be successfully used to monitor food irradiation.  相似文献   
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The numerical abnormalities of human metaphase chromosomes, fixed according to standard procedures for optical microscopy but not treated for banding, were detected by atomic force microscopy (AFM). High-resolution AFM imaging of chromosomes in trisomy 13, 21, and Klinefelter syndrome can be compared directly with the traditional optical image. The unbanded metaphase chromosomes, including the extra ones in trisomic patients showed a structural pattern very similar to G-banding. Comparison of AFM images with light microscopic data allows the identification of specific chromosomes, and images of chromosomes showing numerical and structural abnormalities can then be analysed.  相似文献   
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The identification of foodborne microorganisms and their endospores in food products are important for food safety. The present work compares Bacillus (Bacillus licheniformis, Bacillus circulans and Bacillus subtilis) and Micrococcus (Micrococcus luteus) species with Fourier transform infrared (FTIR) spectroscopy. Our results show that there are several characteristic peaks belonging to both the Micrococcus and Bacillus species which can be used for the identification of these foodborne bacteria and their endospores. For Micrococcus species, a new band was observed at 1338 cm−1 which may be due to acetate oxidation via the carboxylic acid cycle. The bands at 1313 cm−1 and 1256 cm−1 can be explained by an exopolymer formation and the other bands at 1074 cm−1 and 550 cm−1, may be due to the glycogen-like storage material in Micrococcus spp. There are also characteristic peaks at 993 cm−1 and 801 cm−1 for these bacterial species. Different Bacillus species also showed characteristic peaks at 1000–500 cm−1 region. Dipicolinic acid (DPA) bands at ∼728 cm−1 and ∼703 cm−1 seen only in B. circulans were the marker of an endospore formation.  相似文献   
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Betulin is an important triterpenoid substance isolated from birch bark, which, together with its sulfates, exhibits important bioactive properties. We report on a newly developed method of betulin sulfation with sulfamic acid in pyridine in the presence of an Amberlyst®15 solid acid catalyst. It has been shown that this catalyst remains stable when being repeatedly (up to four cycles) used and ensures obtaining of sulfated betulin with a sulfur content of ~10%. The introduction of the sulfate group into the betulin molecule has been proven by Fourier-transform infrared, ultraviolet-visible, and nuclear magnetic resonance spectroscopy. The Fourier-transform infrared (FTIR) spectra contain absorption bands at 1249 and 835–841 cm−1; in the UV spectra, the peak intensity decreases; and, in the nuclear magnetic resonance (NMR) spectra, of betulin disulfate, carbons С3 and С28 are completely shifted to the weak-field region (to 88.21 and 67.32 ppm, respectively) with respect to betulin. Using the potentiometric titration method, the product of acidity constants K1 and K2 of a solution of the betulin disulfate H+ form has been found to be 3.86 × 10–6 ± 0.004. It has been demonstrated by the thermal analysis that betulin and the betulin disulfate sodium salt are stable at temperatures of up to 240 and 220 °C, respectively. The density functional theory method has been used to obtain data on the most stable conformations, molecular electrostatic potential, frontier molecular orbitals, and mulliken atomic charges of betulin and betulin disulfate and to calculate the spectral characteristics of initial and sulfated betulin, which agree well with the experimental data.  相似文献   
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The effects of selenium supplementation on apex and right ventricle myocardia of the rat heart were investigated using Fourier transform infrared (FTIR) spectroscopy by examining the changes in the frequency values of major absorptions arising from lipids and proteins. Cluster analysis was used to discriminate the selenium treated group from the control by utilizing two distinct spectral regions, belonging to absorptions arising from lipids and proteins, respectively. In addition, protein secondary structures were predicted using neural network analysis. The results suggest that selenium treatment at a non-toxic dose causes some significant structural alterations in lipids and proteins of rat heart apex and right ventricle myocardia, which might be revealing a slight deleterious effect of selenium supplementation.  相似文献   
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Splitting tensile strength is one of the important mechanical properties of concrete that is used in structural design. In this paper, it is aimed to propose formulation for predicting cylinder splitting tensile strength of concrete by using gene expression programming (GEP). The database used for training, testing, and validation sets of the GEP models is obtained from the literature. The GEP formulations are developed for prediction of splitting tensile strength of concrete as a function of water-binder ratio, age of specimen, and 100-mm cube compressive strength. The training and testing sets of the GEP models are randomly selected from the complete experimental data. The GEP formulations are also validated with additional experimental data except from the data used in training and testing sets of the GEP models. GEP formulations’ results are compared with experimental results. Results of this study revealed that GEP formulations exhibited better performance to predict the splitting tensile strength of concrete.  相似文献   
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This paper discusses barriers to civic engagement of disadvantaged young people that we observed in the course of a child-friendly city project in Turkey. It also emphasizes the importance of being prepared to overcome such barriers, some of which were quite unexpected. Results show that many of the unexpected issues are the outcome of poverty, illiteracy, lack of ethics, inexperience of project managers, conflicting political interests and sense of insecurity. The paper concludes with suggestions for researchers and policy-makers on how to overcome such unforeseen barriers to child and youth participation in disadvantaged communities.  相似文献   
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