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71.
Olena Vaneeva 《Communications in Nonlinear Science & Numerical Simulation》2012,17(2):611-618
Group classification of classes of mKdV-like equations with time-dependent coefficients is carried out. The usage of equivalence transformations appears to be a crucial point for the exhaustive solution of the problem. We prove that all the classes under consideration are normalized. This allows us to formulate the classification results in three ways: up to two kinds of equivalence (which are generated by transformations from the corresponding equivalence groups and all admissible point transformations) and using no equivalence. A simple way for the construction of exact solutions of mKdV-like equations using equivalence transformations is described. 相似文献
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Rostislav Bukasov Olena Filchakova Kristina Gudun Mohamed Bouhrara 《Journal of fluorescence》2018,28(1):1-4
Strong surface (metal) enhanced fluorescence (SEF or MEF) is observed from clusters and single E coli bacteria cells labeled with Carbon nanodots (CDs), which were synthesized from date pits. The enhancement factor (EF) for SEF of the cell clusters were close to 50 for both 533 and 633 nm laser excitation wavelength. Those EFs are ratios of emission peak areas from CD labeled cell clusters on gold film to the peak areas of the same batch cell clusters on glass substrate. SEF with 633 nm excitation performed better than SEF with 532 nm excitation, achieving higher fluorescence intensity and much higher contrast. The contrast as high as 66 for cell clusters on gold film is a ratio of fluorescent emission peak area measured at the CD labeled cell clusters to the fluorescent peak area measured at unlabeled cell clusters (autofluorescence) on the same substrate. The contrast with the background (S/N) or the ratio of fluorescent peak area measured at bacteria cells to area measured at bare substrate was as high as 200. This report may pave a way for the broader application of surface enhanced fluorescence and especially metal enhanced fluorescence imaging of CD labeled cells and other biological objects. 相似文献
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Lindner BD Engelhart JU Märken M Tverskoy O Appleton AL Rominger F Hardcastle KI Enders M Bunz UH 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(15):4627-4633
A series of functionalized diaza- and tetraazatetracenes was synthesized, either by condensation of an aromatic diamine with an ortho-quinone/diethyloxalate followed by chlorination with POCl(3) to give diazatetracenes or by palladium-catalyzed coupling of a phenylenediamine with various 2,3-dichloroquinoxalines to give tetraazatetracenes (after oxidation with MnO(2)). Representative examples included halogenated and nitrated derivatives. The optical properties of these azatetracenes were discussed with respect to their molecular structures and substitution patterns. The diazatetracenes and tetraazatetracenes formed two different groups that had significantly different electronic structures and properties. Furthermore, 1,2,3,4-tetrafluoro-6,11-bis((triisopropylsilyl)ethynyl)benzo[b]phenazine was synthesized, which is the first reported fluorinated diazatetracene. Single-crystal X-ray analysis of this compound is reported. 相似文献
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Olena Kudina Olga Budishevska Andriy Voronov Ananiy Kohut Olena Khomenko Stanislav Voronov 《Macromolecular Symposia》2010,298(1):79-84
Summary: Novel amphiphilic comb-like poly(α-olefin-co-maleic anhydride) with a controlled ratio of hydrophilic (polyoxyethylene) and hydrophobic (polymethylene) side chains have been synthesized and characterized. The comb-like copolymers are soluble in organic and aqueous media and form micelles whose behaviour could be correlated to the chemical structure of polymers. We foresee that amphiphilic properties of the novel comb-like polymers are obviously the basis of new architectures in solution which could be used in a broad range of applications. Using micelles from these copolymers, silver nanoparticles with a narrow particle size distribution have been obtained as stable dispersion in both polar and non-polar media. 相似文献
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Ganna Zaychenko Olena Stryga Oksana Sinitsyna Anna Doroshenko Oksana Sulaieva Tetyana Falalyeyeva Nazarii Kobyliak 《Molecules (Basel, Switzerland)》2022,27(15)
Phytoestrogen resveratrol (R) has been demonstrated to benefit human reproductive health. However, R bioavailability and pharmacokinetics are still problematic under oral supplementation. We used an experimental vaginal gel with R and hyaluronic acid (HA) to improve bioavailability and pharmacokinetic properties. The study aimed to assess the impact of vaginal R-HA gel on the reproductive system in ovariectomized rats. Methods: The study was carried out on Wistar female rats. It investigated the body weight, tail temperature, vaginal pH, estrogen and progesterone blood levels, and immunohistochemical biomarkers (COX2, Casp-3, Bcl-2, and VEGF). Animals were divided into control animals; ovariectomized rats (OVX); and OVX group treated with vaginal 0.5% R-HA gel (0.5%, 0.1 mL, daily 28 days). Results: The R-HA gel’s therapeutic effect was manifested by slowing weight gain by 17% (p < 0.001), less pronounced symptom of fever at the root of the tail by 9% (p < 0.001) and lowering the vaginal pH to 4.4–4.5 compared with OVX rats. The anti-inflammatory effect and the reduction of COX-2 expression in vagina were accompanied by antiapoptotic impact of RA-H on endometrium, associated with the decreased Casp-3 expression (p < 0.001) and elevated Bcl-2 score in endometrial glands (p = 0.01). Together with enhanced VEGF expression in endometrial glands (p < 0.001) and stromal cells (p = 0.007), these changes prevented endometrial atrophy (p < 0.001) after ovariectomy. Thus, this study substantiates the feasibility of developing an innovative topical drug with R and HA for treating hypoestrogenic disorders. 相似文献
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Sergeyev S Schär M Seiler P Lukoyanova O Echegoyen L Diederich F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(8):2284-2294
The double Bingel reaction of fullerene C60 with bismalonates attached to a Tr?ger base derived tether afforded trans-1, trans-2, trans-3, and trans-4 bisadducts with excellent regioselectivity. In particular, enantiomerically pure bisadducts with inherently chiral trans-2 or trans-3 addition patterns were prepared starting from enantiomerically pure bismalonates. The absolute configuration of the trans-2 and trans-3 bisadducts was established from their CD spectra. The excellent diastereoselectivity in the double additions to give the trans-2 bisadducts is particularly remarkable given the large distance between the two reacting bonds in opposite hemispheres of the fullerene that is spanned by the tether. Now, all inherently chiral double addition patterns are readily available by tether-directed functionalization using appropriate chiral, nonracemic spacers. 相似文献
79.
Haudenschild BL Maydanovych O Véliz EA Macbeth MR Bass BL Beal PA 《Journal of the American Chemical Society》2004,126(36):11213-11219
Deamination at C6 of adenosine in RNA catalyzed by the ADAR enzymes generates inosine at the corresponding position. Because inosine is decoded as guanosine during translation, this modification can lead to codon changes in messenger RNA. Hydration of 8-azanebularine across the C6-N1 double bond generates an excellent mimic of the transition state proposed for the hydrolytic deamination reaction catalyzed by ADARs. Here, we report the synthesis of a phosphoramidite of 8-azanebularine and its use in the preparation of RNAs mimicking the secondary structure found at a known editing site in the glutamate receptor B subunit pre-mRNA. The binding properties of analogue-containing RNAs indicate that a tight binding ligand for an ADAR can be generated by incorporation of 8-azanebularine. The observed high-affinity binding is dependent on a functional active site, the presence of one, but not the other, of ADAR2's two double-stranded RNA-binding motifs (dsRBMs), and the correct placement of the nucleoside analogue into the sequence/structural context of a known editing site. These results advance our understanding of substrate recognition during ADAR-catalyzed RNA editing and are important for structural studies of ADAR.RNA complexes. 相似文献
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