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Kažoka Helena Turovska Baiba Upmanis Toms Orlova Natalja Vorona Maksims 《Chromatographia》2021,84(7):663-675
Chromatographia - Our previous studies concerning the enantioseparation of 4C-substituted pyrrolidin-2-one derivatives on coated polysaccharide-based chiral stationary phases have shown that... 相似文献
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The primary goal of this study was to describe and compare the criteria used to assess carcinogenic activity. The statistically-based predictive quantitative structure–activity relationship (QSAR) models based on the counter propagation artificial neural network (CPANN) algorithm, and knowledge-based expert systems based on a decision tree structural alert (SA) approach (Toxtree application), were considered. The integration of the QSAR (CPANN models) and SAR (Toxtree SA application) approach contributed to the mechanistic understanding of the QSAR model considered. The mapping technique inherent to CPANN Kohonen enables us to relate the similarities or dissimilarities within a congeneric set of chemicals with particular SAs for carcinogenicity. The focus of our investigations was the similarities and dissimilarities of the features used in the QSAR and SAR methods. Due to the complexity of the carcinogenic endpoint, the integration of different approaches allows the models to be improved and provides a valuable technique for evaluating the safety of chemicals. 相似文献
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Elena M. Kirilova Inta Kalnina Tija Zvagule Natalija Gabruseva Natalja Kurjane Irina I. Solomenikova 《Journal of fluorescence》2011,21(3):923-927
The use of hydrophobic fluorescent probe ABM (benzanthrone derivative) and albumin autofluorescence allowed show conformational
alterations in Chernobyl clean-up workers blood plasma. Results obtained in 1996–1997 suggest that acidic expansion of plasma
albumin takes place. Latest data (2006–2008) result in splitting of albumin alterations onto two stages - acidic expansion
and N-F transition. The N-F transition is accompanied by the blue shift of fluorescence spectra and dehydration of tryptophanyl
region of albumin molecule. In 2007 obtained.patterns of ABM spectra had never been previously seen in examined healthy individuals
or patients with tuberculosis, multiple sclerosis, rheumatoid arthritis, etc. Patterns of ABM fluorescence spectra are associated
with conformational changes of blood plasma albumin. The use of probe ABM and albumin auto-fluorescence allowed show conformational
alterations in albumin of Chernobyl clean-up workers blood plasma. It is necessary to note that all investigated parameters
significantly differ in observed groups of patients. These findings reinforce our understanding that the blood plasma albumin
is a significant biological target of radiation. It may be concluded that fluorescence characteristics are representative
of radiation induced albumin alterations and its carrier function. 相似文献
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We study the temporal dynamics of the generalized repressilator, a network of coupled repressing genes arranged in a directed ring topology, and give analytical conditions for the emergence of a finite sequence of unstable periodic orbits that lead to reachable long-lived oscillating transients. Such transients dominate the finite time horizon dynamics that is relevant in confined, noisy environments such as bacterial cells (see our previous work [Strelkowa and Barahona, J. R. Soc. Interface 7, 1071 (2010)]), and are therefore of interest for bioengineering and synthetic biology. We show that the family of unstable orbits possesses spatial symmetries and can also be understood in terms of traveling wave solutions of kink-like topological defects. The long-lived oscillatory transients correspond to the propagation of quasistable two-kink configurations that unravel over a long time. We also assess the similarities between the generalized repressilator model and other unidirectionally coupled electronic systems, such as magnetic flux gates, which have been implemented experimentally. 相似文献
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Novel Mechanism of Bioluminescence: Oxidative Decarboxylation of a Moiety Adjacent to the Light Emitter of Fridericia Luciferin 下载免费PDF全文
Maxim A. Dubinnyi Zinaida M. Kaskova Natalja S. Rodionova Mikhail S. Baranov Andrey Yu. Gorokhovatsky Alexey Kotlobay Kyril M. Solntsev Aleksandra S. Tsarkova Valentin N. Petushkov Ilia V. Yampolsky 《Angewandte Chemie (International ed. in English)》2015,54(24):7065-7067
A novel luciferin from a bioluminescent Siberian earthworm Fridericia heliota was recently described. In this study, the Fridericia oxyluciferin was isolated and its structure elucidated. The results provide insight into a novel bioluminescence mechanism in nature. Oxidative decarboxylation of a lysine fragment of the luciferin supplies energy for light generation, while a fluorescent CompX moiety remains intact and serves as the light emitter. 相似文献
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Isomerism, conformations, and molecular structure of a model molecule of vitamin K1 with a truncated side chain have been studied by the density functional theory calculations using B3LYP method and double-
and triple-ζ correlation consistent basis sets. The conformations of two possible (E and Z) isomers, formed by the rotations around three single C–C bonds closest to the naphthoquinone ring, have been studied. The
lowest energy conformers are stabilized by additional hydrogen bonds between hydrogen atoms of the side chain and an oxygen
atom in the naphthoquinone subunit. It is interesting to note that the structure of the energetically preferred conformer
of the E-isomer (3c) has been found to be similar to the solid state structures of phylloquinones in the photosystem I of cyanobacterium
Synechococcus elongatus. The excited electronic states of two lowest energy conformers have also been investigated. 相似文献
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Engineering optimization is an actual goal in manufacturing and service industries. In the tutorial we represented the concept of traditional parametric estimation models (Factorial Design (FD) and Central Composite Design (CCD)) for searching optimal setting parameters of technological processes. Then the 2D mapping method based on Auto Associative Neural Networks (ANN) (particularly, the Feed Forward Bottle Neck Neural Network (FFBN NN)) was described in comparison with traditional methods. 相似文献