High biological activity of natural furocoumarins is often linked to a series of adverse side effects, e.g., genotoxicity. This makes it desirable to develop semi-synthetic derivatives with reduced ...negative activity while retaining or even enhancing the positive properties. Previously, we have studied the genotoxic activity of a library of twenty-one 1,2,3-triazolyl-modified furocoumarins and 2,3-dihydrofurocoumarins and identified modifications that minimize the negative properties. In the current article, we report on an investigation into the cytotoxic activity of the same library. We have aimed to rank the substances in order of the severity of their cytotoxicity and therefore to predict, with the use of statistical processing, the most promising substituents for the furocoumarin scaffold.
The furocoumarin backbone is a promising platform for chemical modifications aimed at creating new pharmaceutical agents. However, the high level of biological activity of furocoumarins is associated ...with a number of negative effects. For example, some of the naturally occurring ones and their derivatives can show genotoxic and mutagenic properties as a result of their forming crosslinks with DNA molecules. Therefore, a particularly important area for the chemical modification of natural furocoumarins is to reduce the negative aspects of their bioactivity. By studying a group of 21 compounds-1,2,3-triazolyl modified derivatives of furocoumarin and peucedanin-using the SOS chromotest, the Ames test, and DNA-comet assays, we revealed modifications that can neutralize the structure's genotoxic properties. Theoretical aspects of the interaction of the compound library were studied using molecular modeling and this identified the leading role of the polyaromatic molecular core that takes part in stacking-interactions with the pi-systems of the nitrogenous bases of DNA.
The results of the development of a thermal imaging device based on the FEM10M photodetector produced by the Orion Research and Production Association are presented. As a result of the implementation ...of measures for improvement of the TPK-Z thermal imaging camera so as to comply with a domestic photodetector, the TPK-ZR thermal imaging device based on a domestic multirow array was developed, tuned, and tested. The minimum allowed temperature difference (MATD) and noise equivalent temperature difference (NETD) characteristics of the device are at least as good as the corresponding characteristics of a thermal imager using a foreign photodetector. The complex of image processing algorithms used in the TPK-ZR device makes it possible to obtain thermal images whose quality is not worse then the quality of the images obtained with the TPK-Z device. Further development of the obtained result can be implementation of a series of measures aimed at achieving full automation of calibration processes in the thermal imager.
To reveal the tissue, cellular, and molecular predictors leading to the development of chronic obstructive pulmonary disease (COPD) in smokers on the basis of a morphometric analysis of bronchial ...biopsy specimens.
A cross-sectional study was conducted in 115 smokers aged 40 to 60 years (58.3±3.24 years) with a male predominance of 90.9%. Morphological examination of bronchial biopsy specimens was first made in the smoking patients with and without COPD.
The smokers with COPD versus those without this condition were found to have a statistically significant increase in a number of indicators: the specific volume (SV) of the surface epithelium (p=0.017), SV of basal epitheliocytes (p=0.008), the height of the epithelium (p=0.001), and the thickness of the basal membrane (p=0.006) due to impaired regeneration processes in the bronchial epithelium and to fibrosis of the lamina propria of the bronchi with a concurrent increase in the total number of fibroblasts. The group of smokers with COPD, unlike the comparison group, showed signs of vascular remodeling and microcirculatory disorders as the increased connective tissue volumetric density of the lamina propria of the bronchi with predominant perivascular localization. This was followed by reductions in the relative volume of capillaries (p=0.016), in the SV of micropinocytic vesicles (p=0.005), and the size of Weibel-Palade bodies (p=0.004) in the endotheliocytes. In the COPD patients, the total density of cell infiltrate per mm2 of the lamina propria of the bronchi was statistically significantly (p<0.001) greater than that in the comparison group at the expense of neutrophils, lowly and moderately granulated basophils, macrophages, plasma cells with a simultaneous rise in their interepithelial forms.
Compensatory structural changes without signs of bronchial wall remodeling were recorded in the smokers without signs of bronchial disease. The smokers with the examined nosological entity were observed to have morphological signs of hemodynamic disorders, as well as perivascular fibrosis, atrophy, and squamous cell metaplasia of the bronchial epithelial lining.
The vibration activity of microcryogenic machine is an important factor determining the lifetime characteristics of matrix photodetector devices (PDD) operating in the IR range of the spectrum. The ...frequency responses of the vibration activity of the PDD of different manufacturers with different service lives are given. Vibration activity is measured using a strain gauge rigidly connected to the base of the PDD. The influence of centrifugal and compression forces on the vibration activity of the PDD and the possibility of their mutual compensation are analyzed.
—Design and fabrication of photosensitive array elements in the 384 × 288 element format with a step of 25 μm with a long wavelength limit of sensitivity at 0.5 to approximately 9.5 μm were ...performed. The circuit and topology were developed, according to which matrix high-speed multiplexers are manufactured in the form of 384 × 288 elements with a step of 25 microns, which provide operating modes at a clock frequency of up to 20 MHz. The 384 × 288 element hybrid photodetector (PD) format in 25 μm increments has an average Noise Equivalent Temperature Difference (NETD) of less than 30 mK, while the number of working elements was more than 97%. Examples are given of using the microscanning system to reduce defective pixels in an image frame and/or increase the frame format to 768 × 576. It is shown that as a result of the use of microscans in a thermal imaging channel based on the developed PD during the transition to the 768 × 576 format, an improvement in spatial resolution of 1.4 times was obtained for the same minimum resolved temperature difference (MRTD), while the MRTD at a frequency of 0.44 mrad
-1
decreased from 1.6 to 0.9 K compared to the original 384 × 288 format.
The designs of a warm (uncooled) aperture diaphragm in a gas-filled cryostat with a matrix photodetector sensitive in the infrared spectral range are studied numerically and experimentally. It is ...shown that for the chosen design of a warm aperture diaphragm, a
pixel matrix photodetector is cooled by liquid nitrogen to operating temperatures (85 K) in less than 40 seconds, and by a throttle microcooler in 15 seconds, while maintaining the standard sensitivity of photodetectors based on cadmium–mercury–tellurium (CMT) structures.
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