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81.
Brief analysis of the metabolism of nitric oxide in living cells in normal state and pathology and also the analysis of the causes that hampered the progress of these studies were carried out. It was established that most of physiological fluids, including blood, normally contain nitrite and non-thiolate nitroso compounds in concentration less than 100 nM. Literature data from different researchers on the normal range of nitrite concentration in plasma of healthy people from several hundreds of nM to several μM is probably the result of low selectivity of the methods used. But nitrite and non-thiolate nitroso compounds concentration in blood is dramatically increased in case of inflammatory diseases. It is proposed that the main mechanism for the production of these substances in blood is the nitrosyl iron complexes transformation by active oxygen species but not the activation of NO production as it was considered previously. 相似文献
82.
83.
Grachev AA Gerbst AG Gening ML Titov DV Yudina ON Tsvetkov YE Shashkov AS Pier GB Nifantiev NE 《Carbohydrate research》2011,346(15):2499-2510
The conformational behavior of a series of linear and cyclic oligo-(1→6)-β-D-glucosamines and their N-acetylated derivatives, which are related to fragments of natural poly-N-acetylglucosamine, was studied by theoretical molecular modeling and experimental determination of transglycosidic vicinal coupling constants (3)J(C,H) and (3)J(H,H). Molecular dynamics simulations were performed under several types of conditions varying in the consideration of ionization of amino groups, solvent effect, and temperature. Neural network clustering and asphericity calculations were performed on the basis of molecular dynamics data. It was shown that disaccharide fragments in the studied linear oligosaccharides were not rigid, and tended to have several conformers, thus determining the overall twisted shape with helical elements. In addition, it was found that the behavior of C5-C6 bond depended significantly upon the simulation conditions. The cyclic di-, tri-, and tetrasaccharides mostly had symmetrical ring-shaped conformations. The larger cycles tended to adopt more complicated shapes, and the conformational behavior of their disaccharide fragments was close to that in the linear oligosaccharides. 相似文献
84.
Alexey A. Grachev Alexey G. Gerbst Marina L. Gening Denis V. Titov Olga N. Yudina Yury E. Tsvetkov Alexander S. Shashkov Gerald B. Pier Nikolay E. Nifantiev 《Carbohydrate research》2011,(15):2499
The conformational behavior of a series of linear and cyclic oligo-(1→6)-β-d-glucosamines and their N-acetylated derivatives, which are related to fragments of natural poly-N-acetylglucosamine, was studied by theoretical molecular modeling and experimental determination of transglycosidic vicinal coupling constants 3JC,H and 3JH,H. Molecular dynamics simulations were performed under several types of conditions varying in the consideration of ionization of amino groups, solvent effect, and temperature. Neural network clustering and asphericity calculations were performed on the basis of molecular dynamics data. It was shown that disaccharide fragments in the studied linear oligosaccharides were not rigid, and tended to have several conformers, thus determining the overall twisted shape with helical elements. In addition, it was found that the behavior of C5–C6 bond depended significantly upon the simulation conditions. The cyclic di-, tri-, and tetrasaccharides mostly had symmetrical ring-shaped conformations. The larger cycles tended to adopt more complicated shapes, and the conformational behavior of their disaccharide fragments was close to that in the linear oligosaccharides. 相似文献
85.
研究了体外培养一种孟加拉传统香蕉(Musa spp.Cv. Kanthali)的茎尖组织。茎尖的原始细胞表面经无菌处理(0.1%HgCl2处理12min) ,接种6~15d后外植体地下茎部分仍有微生物污染(大部分是细菌) ,杀死了85%的外植体。为确定无污染培养基,将等量外植体分别浸泡在含400mg/L氨苄青霉素和200mg/L庆大霉素(两种光谱抗生素)的培养基中1h。结果表明,经抗生素处理的外植体完全没有污染,但培养3周后不能再生。进行二次继代培养后,其中一部分外植体吸收了培养基并胀大,颜色由苍白转变成浅绿或深绿。三次继代培养后数天,不再观察到外植体的生长,所有经抗生素处理过的外植体都开始死亡。在未经抗生素处理的活外植体中,单个茎发育的最佳培养基是:MS 4.0mg/L BA 0.5mg/L KT 15% CW,平均生长时间为18~21d,但再生率很低,只有30%。茎细胞增殖的最佳培养基是:MS 4.0mg/L BA 2.0mg/LIAA 15% CW,每个茎平均只萌发3~4个芽。最后,在添加0.5mg/LIBA的一半浓度的MS培养基中,体外培养茎最大生根率达到90%。 相似文献
86.
Soubir Titov 《生物工程学报》2007,23(2):257-261
研究了A.heterophyllus,A.squamosa,T.bellirica,S.samarangense,A.carambolaand O.europ水果的抗氧化活性。首先将这些成熟的水果切成小片,然后用日光晒干,最后用研磨器磨成粉末。这些水果粉末用99·99%的乙醇进行乙醇提取。这些提取物的活性通过其清除稳定的1,1-diphenyl-2-picrylhydrazyl(DPPH)自由基的能力进行测定。实验结果表明,所有A.heterophyllus,A.squamosa,T.bellirica,S.samarangense,A.carambolaand O.europa这些水果的乙醇提取物都具有抗氧化活性,这些水果的乙醇提取物的的IC50值分别是410,250,34,200,30和76μg/mL。其中A.carambola具有最高的抗氧化活性,其次是T.bellirica,O.europa,S.samarangense,A.squamosa和A.heterophyllus。结果表明A.carambola,T.bellirica和O.europa对人体健康是非常有益的。 相似文献
87.
研究了体外培养一种孟加拉传统香蕉(Musa spp. Cv. Kanthali)的茎尖组织。茎尖的原始细胞表面经无菌处理(0.1% HgCl2处理12min),接种6~15d后外植体地下茎部分仍有微生物污染(大部分是细菌),杀死了85%的外植体。为确定无污染培养基,将等量外植体分别浸泡在含400mg/L氨苄青霉素和200mg/L庆大霉素(两种光谱抗生素)的培养基中1h。结果表明,经抗生素处理的外植体完全没有污染,但培养3周后不能再生。进行二次继代培养后,其中一部分外植体吸收了培养基并胀大,颜色由苍白转变成浅绿或深绿。三次继代培养后数天,不再观察到外植体的生长,所有经抗生素处理过的外植体都开始死亡。在未经抗生素处理的活外植体中,单个茎发育的最佳培养基是:MS+4.0mg/L BA+0.5mg/L KT+15% CW,平均生长时间为18~21d,但再生率很低,只有30%。茎细胞增殖的最佳培养基是:MS+4.0mg/L BA+2.0mg/L IAA+15% CW,每个茎平均只萌发3~4个芽。最后,在添加0.5mg/L IBA的一半浓度的MS培养基中,体外培养茎最大生根率达到90%。 相似文献
88.
Gerhard Andersson Nickolai Titov Blake F. Dear Alexander Rozental Per Carlbring 《World psychiatry》2019,18(1):20-28
Internet interventions, and in particular Internet‐delivered cognitive behaviour therapy (ICBT), have existed for at least 20 years. Here we review the treatment approach and the evidence base, arguing that ICBT can be viewed as a vehicle for innovation. ICBT has been developed and tested for several psychiatric and somatic conditions, and direct comparative studies suggest that therapist‐guided ICBT is more effective than a waiting list for anxiety disorders and depression, and tends to be as effective as face‐to‐face CBT. Studies on the possible harmful effects of ICBT are also reviewed: a significant minority of people do experience negative effects, although rates of deterioration appear similar to those reported for face‐to‐face treatments and lower than for control conditions. We further review studies on change mechanisms and conclude that few, if any, consistent moderators and mediators of change have been identified. A recent trend to focus on knowledge acquisition is considered, and a discussion on the possibilities and hurdles of implementing ICBT is presented. The latter includes findings suggesting that attitudes toward ICBT may not be as positive as when using modern information technology as an adjunct to face‐to‐face therapy (i.e., blended treatment). Finally, we discuss future directions, including the role played by technology and machine learning, blended treatment, adaptation of treatment for minorities and non‐Western settings, other therapeutic approaches than ICBT (including Internet‐delivered psychodynamic and interpersonal psychotherapy as well as acceptance and commitment therapy), emerging regulations, and the importance of reporting failed trials. 相似文献
89.
Conformational and phase transitions in DNA—photosensitive surfactant solutions: Experiment and modeling
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N. Kasyanenko L. Lysyakova R. Ramazanov A. Nesterenko I. Yaroshevich E. Titov G. Alexeev A. Lezov I. Unksov 《Biopolymers》2015,103(2):109-122
DNA binding to trans‐ and cis‐isomers of azobenzene containing cationic surfactant in 5 mM NaCl solution was investigated by the methods of dynamic light scattering (DLS), low‐gradient viscometry (LGV), atomic force microscopy (AFM), circular dichroism (CD), gel electrophoresis (GE), flow birefringence (FB), UV–Vis spectrophotometry. Light‐responsive conformational transitions of DNA in complex with photosensitive surfactant, changes in DNA optical anisotropy and persistent length, phase transition of DNA into nanoparticles induced by high surfactant concentration, as well as transformation of surfactant conformation under its binding to macromolecule were studied. Computer simulations of micelles formation for cis‐ and trans‐isomers of azobenzene containing surfactant, as well as DNA‐surfactant interaction, were carried out. Phase diagram for DNA‐surfactant solutions was designed. The possibility to reverse the DNA packaging induced by surfactant binding with the dilution and light irradiation was shown. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 109–122, 2015. 相似文献
90.
The large mammals from travertine deposits in the Denizli basin include the following species: Archidiskodon meridionalis meridionalis, Equus cf. altidens s. l., E. cf. apolloniensis, Stephanorhinus cf. etruscus, Metacervoceros rhenanus, Cervalces (Libralces) ex gr. minor-gallicus, Palaeotragus sp., Bovinae gen. and sp. indet. This association resembles those from the late Villafranchian of Southern and Eastern Europe, and, to some extent, fromWestern Asia, and could be older than 1.2 Ma. 相似文献