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Fine tuning of pyrene excimer fluorescence in molecular beacons by alteration of the monomer structure
Journal of Organic Chemistry. 2017. Vol. 82. No. 19. P. 10015–10024.
Vladimir A. Korshun
Oligonucleotide probes labeled with pyrene pairs that form excimers have a number of applications in hybridization analysis of nucleic acids. A long excited state lifetime, large Stokes shift, and chemical stability make pyrene excimer
an attractive fluorescent label. Here we report synthesis of chiral phosphoramidite building blocks based on (R)-4- amino-2,2-dimethylbutane-1,3-diol, easily available from an inexpensive D-(−)-pantolactone. 1-Pyreneacetamide, 1-pyrenecarboxamide, and DABCYL derivatives have been used in preparation of molecular beacon (MB) probes labeled with one or two pyrenes/quenchers. We observed significant difference in the excimer emission maxima (475−510 nm; Stokes shifts 125−160 nm or 7520−8960 cm−1) and excimer/monomer ratio (from 0.5 to 5.9) in fluorescence spectra depending on the structure and position of monomers in the pyrene pair. The pyrene excimer formed by two rigid 1-pyrenecarboxamide residues showed the brightest emission. This is consistent with molecular dynamics data on excimer stability. Increase of the excimer fluorescence for MBs after hybridization with DNA was up to 24-fold.
Давидович А. С., Shestakova A., Arzumanyan N. et al., Frontiers in Psychology 2026 Vol. 17 - 2026 P. 1–18
Background:
Delay discounting refers to the tendency to choose sooner, smaller rewards over larger, later rewards. Many previous studies link this tendency positively to reward sensitivity, yet the specific mechanisms behind this association remain poorly understood. Reward sensitivity may relate to delay discounting through at least three possible pathways: increased sensitivity to reward size, increased sensitivity ...
Added: May 27, 2026
Novikov A., Communications in Computational Chemistry 2026 Vol. 8 No. 2 P. 203–210
Chalcogen bonds (ChBs) are often interpreted as 𝜎-hole driven electrostatic interactions between a chalcogen atom and a Lewis base, yet their covalent character remains under active discussion. Here, we present a real-space, reference-free study of prototypical X2Ch···X– complexes (X = F, Cl; Ch = O, S) using the Interacting Quantum Atoms (IQA) energy decomposition within ...
Added: May 27, 2026
Birin K. P., Journal of Photochemistry and Photobiology A: Chemistry 2026 Vol. 474 Article 116936
Oxidation of sulfides by singlet oxygen has been extensively studied, yet the structure-photoactivity relationship of these photosensitizers remains underinvestigated. In the present work the photocatalytic performance of a set of functionalized palladium(II) porphyrinates was comprehensively investigated in the photocatalytic oxidation of sulfides to reveal mutual influence of structural peculiarities onto the photosensitizing properties. The photophysical ...
Added: May 27, 2026
Nazarov A., Sivaev I., Mezentsev I. et al., Journal of Photochemistry and Photobiology A: Chemistry 2026 Vol. 479 Article 117316
Novel cobalt bis(dicarbollide) based terminal alkynes with charge-compensated group in a spacer were synthesized by the nucleophilic ring-opening reactions of cyclic oxonium derivatives of cobalt bis(dicarbollide) with N,N-dimethylbut-3-yn-1-amine. A series of zwitterionic conjugates of cobalt bis(dicarbollide) with BODIPY were synthesized using the copper(I)-catalyzed azide-alkyne cycloaddition reaction. The absorption-emission spectra of the synthesized fluorescent conjugates of cobalt ...
Added: May 27, 2026
Degtyarev A., Bakhurin S., Yudin N., DSPA 2026 P. 1–6
This paper investigates one possible solution to the problem of self-interference cancellation (SIC) arising in the design of in-band full-duplex (IBFD) communication systems. Self-interference cancellation is performed in the digital domain using multilayer nonlinear models adapted via gradient-based optimization. The presence of local minima and saddle points during the adaptation of multilayer models limits the ...
Added: May 26, 2026
Toukach P., Smirnova N. S., Zdorovenko E. L. et al., Analytical Chemistry 2026 Vol. 98 No. 15 P. 10988–10996
Pyruvylation is one of the immunochemically relevant modifications of O-antigens in bacterial and fungal cells. Therefore, fast and relatively simple analytical methods for identifying this modification are highly demanded. 13C NMR spectroscopy is the best candidate for this purpose, but its successful application requires using reference structures and reliable databases. In this work, we collected ...
Added: May 25, 2026
Kochetkova Ekaterina, Kostanian D., Martynova O. et al., Brain Topography 2026 Vol. 39 No. 4 Article 51
Letter recognition is assumed to involve several levels of analysis, including coarse tuning for category and novelty and more fine tuning for specific features, related to letter orientation. We employed an oddball fast periodic visual stimulation (FPVS) paradigm with magnetoencephalography (Elekta VectorView, 306 sensors) to study neural discrimination responses in the source space. Using contrasts ...
Added: May 24, 2026
Qian X., Deng Y., Shchur L. et al., Physica A: Statistical Mechanics and its Applications 2026 Vol. 696 P. 1–13
We perform a Monte Carlo analysis of the Ising model on many three-dimensional lattices. By means of finite-size scaling we obtain the critical points and determine the scaling dimensions. As expected, the critical exponents agree with the three-dimensional Ising universality class for all models. The irrelevant field, as revealed by the correction-to-scaling amplitudes, appears to ...
Added: May 24, 2026
Зверева О., Клюев Ф. С., Lebedeva N. et al., Organic Letters 2025 Vol. 27 No. 50 P. 13711–13716
Added: May 23, 2026
Mikhail A. Losev, Andrey S. Kozlov, Afanasyev O. et al., ACS Catalysis 2026 Vol. 16 No. 10 P. 9380–9386
A convenient, stable, and non-toxic substance, tetrabutylammonium difluorotriphenylsilicate (TBAT), can be used as an organocatalyst in all stages of polymer lifetime: synthesis, modification, and recycling. The fluorine-containing initiator showed high activity in the polymerization of siloxanes compared to classic organocatalytic systems. Using kinetically controlled ROP, a high-molecular-weight PDMS (Mn up to 820 𝑘𝑔/𝑚𝑜𝑙) was prepared at room ...
Added: May 22, 2026
Лосев М. А., Козлов А. С., Клюев Ф. С. et al., Organic and Biomolecular Chemistry 2023 Vol. 21 No. 42 P. 8477–8481
A simple and atom-efficient way to prepare amides directly from carboxylic acids and nitroarenes was developed. Carbon monoxide as a sole reducing agent provides the ultimate selectivity of the protocol. A straightforward and selective way for the preparation of amides from nitroarenes and carboxylic acids using carbon monoxide as a reductant was developed. This protocol ...
Added: May 22, 2026
Melentiev P. N., Калмыков А. С., Гритченко А. С. et al., Успехи физических наук 2024 Т. 194 № 11 С. 1130–1145
Представлен краткий обзор достигнутого уровня оптических методов детектирования единичных молекул в биомедицинских приложениях. Показано, что регистрация флуоресценции единичных молекул красителей, ковалентно связанных с антителами (биомолекулами), совместно с использованием современных методов нанофотоники может быть применена для решения различных задач в биологии и медицине: визуализации биомолекул, токсинов, вирусных частиц, определения ультранизких концентраций аналитов напрямую во взятой пробе, ...
Added: May 21, 2026
Borovikova I., Okhrimenko G., Zamyatin V. et al., Journal of Structural Biology 2026 Vol. 218 No. 2 Article 108315
Single amino acid substitutions in the ATP-binding domain of ACVRL1, a key receptor in the bone morphogenetic protein (BMP) signaling pathway, are frequently classified as variants of uncertain significance (VUS), complicating molecular diagnosis for pulmonary arterial hypertension (PAH) and Hereditary Hemorrhagic Telangiectasia (HHT). Since aberrant ATP binding disrupts downstream SMAD1/5/8 phosphorylation, we employed molecular dynamics ...
Added: May 20, 2026
Antsiferov P.S., Stepanov L.V., Matiukhin N. D., Review of Scientific Instruments 2025 Vol. 96 No. 12 Article 123506
The article presents the discharge plasma based source of extreme ultraviolet (EUV) radiation. The discharge circuit has been driven by means of stripe line storage with working voltage 10.5 kV. The main feature of the proposed source is that plasma electrons acquire the energy, necessary for the production of multiply charged ions with ionization potentials ...
Added: May 20, 2026
Анциферов П. С., Степанов Л. В., Матюхин Н. Д., Оптика и спектроскопия 2026 Т. 134 № 2 С. 214–218
Сообщено о разработке системы регистрации спектров на ПЗС-линейке для уникального ВУФ спектрометра, построенного на основе сферической дифракционной решетки с радиусом 6.65 m. Была использована линейка HAMAMATSU S11156-2048-02, которая устанавливалась по касательной к окружности Роуланда с возможностью механического перемещения для сканирования спектра. Были получены спектрограммы в диапазоне длин волн 2130-2270 Angstrem. Описана методика сшивки регистрируемых спектральных ...
Added: May 20, 2026
Shipilov F., Barnyakov A., Ivanov A. et al., / Series Physics "arxiv.org". 2026.
A fast simulation of the detector response is a vital task in high-energy physics (HEP). Traditional Monte-Carlo methods form the backbone of modern particle physics simulation software but are computationally expensive. We present a machine-learning-based approach to fast simulation of the Focusing Aerogel Ring Imaging Cherenkov (FARICH) detector response. Given a particle track and momentum, ...
Added: May 19, 2026
Malinovsky A. M., Пилипенко С. В., Mikhalchenko A. O. et al., Astronomy Reports 2026 Vol. 70 P. 1–6
Radiation from rotational transitions of CO molecules in distant galaxies creates a chaotic background with an intensity reaching 1000 Jy/sr at a wavelength of approximately 1 mm. This background will pose a serious problem, when measuring spectral distortions of the cosmic microwave background, in particular, the mu-distortion, which presumably has an intensity of less than ...
Added: May 19, 2026
Goltseva Y., Tsokolaeva Z., Beloglazova I. et al., Stem Cell Research and Therapy 2026 Vol. 17 No. 1 Article 112
Background Cardiac fibrosis represents a significant health burden, with endothelial dysfunction and damaged
perivascular microenvironment increasingly recognized as key contributors to fibrotic remodeling. The urokinase
plasminogen activator receptor (uPAR), a critical component of the urokinase system, plays a pivotal role in vascular
remodeling and fibrosis. While prior evidence indicates that uPAR deficiency leads to microvascular dysfunction and
perivascular fibrosis, ...
Added: May 19, 2026
Гущина В. А., / Series chemrxiv-2023-vpzhz-v2 "ChemRxiv". 2023.
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are being intensively studied due to their unique properties and wide range of applications; however, however, the nature of their optical properties is not yet fully understood due to the difficulty of synthesis of singlephase nanoparticles. In this article we describe the features of the synthesis of single-phase particles ...
Added: May 14, 2026
Erzunov D., Alekseeva A., Sarvin I. et al., Journal of Porphyrins and Phthalocyanines 2024 Vol. 28 No. 09n10 P. 701–709
Peripheral phenyl-substituted metal phthalocyanines with thio and oxa substitution in the spacer bridge fragment were obtained in the work. Spectroscopic properties were studied for the obtained complexes, and the main patterns of behavior and characteristics change depending on the solvent and the nature of the spacer atom. It is shown that the replacement of an oxygen ...
Added: September 16, 2025
Курмаз С. В., Иванова И., Фадеева Н. В. et al., Известия Академии наук. Серия химическая 2023 Т. 72 № 6 С. 1349–1365
Polymer compositions of folic acid based on an amphiphilic copolymer of N-vinylpyrrolidone with methacrylic acid branched with triethylene glycol dimethacrylate have been developed and characterized by the methods of DLS, 1H NMR, IRS, DSC and TGA in solutions and in solid state. The effective binding constants of folic acid to copolymer in isopropyl alcohol and ...
Added: September 14, 2025
Alimov O., Doroshenko M., Egorysheva A. et al., Optical Materials 2022 Vol. 128 Article 112330
The optical properties of a highly dispersed bismuth orthogermanate powder (HDP_BGO) were studied at 300 K. The fluorescence of undoped HDP_BGO under ultraviolet (UV) excitation (266nm) was shown to result from Frenkel excitons. The HDP_BGO fluorescence decay kinetics under UV excitation had a complex decay form similar to that of BGO single crystal and was a ...
Added: October 23, 2022
Федосеева Е. В., Григорьева И. Ю., Николаева О.В. et al., Вопросы современной альгологии 2020 № 2(23) С. 40–45
Algae tests are widely used due to the availability of cultivation conditions and high reproducibility. Freshwater and marine algae are used to estimate the toxicity of drinking, natural and wastewater, water extracts from soils, sewage sludge and production and consumption waste. The presence of dissolved organic matter in the samples, stimulating the growth of algae ...
Added: July 8, 2022
Khoroshutin A. V., Lypenko D. A., Korlyukov A. et al., Synthetic Metals 2022 Vol. 287 Article 117094
A series of tricyclic naphthothiophenes – photocyclization products (8-methoxynaphtho[1,2-b]thiophene; 6,7-dimethoxynaphtho[1,2-b]thiophene; 8-methoxynaphtho[2,1-b]thiophene) have been studied. HOMO and LUMO levels, as well as a gap between them was accessed by cyclic voltammetry and optical spectroscopy. Double potential step chronoamperometry showed that the former naphthothiophene exhibits slower current decay than the other substances. Charge carrier mobility measured by the CELIV technique was ...
Added: June 7, 2022