5 research outputs found
New Generation Software-Only Architecture for Gaze-Contingent Eyetracking Experimentation
No full textThe author shares 10+ years of experience in eyetracking research. Most crucial technicalities are described, different programming approaches are discussed. Network Time Protocol [19] application to data stream synchronization is reviewed separately, which renders phototransistor on-screen sensors partially redundant in some of psychophysics disciplines (known as TTL hardware).</p
The Demidoff Church in the San Donato Estate in Florence
No full textThe article is about the decoration of the former Demidoffs’ house church in the villa of San
Donato. A part of it is now located in the church of the Nativity of Christ and St. Nicholas
the Thaumaturge in Florence (architect M. T. Preobrazhensky). The author has suggested the
probable appearance of the house church in the villa of San Donato based on notes of contemporaries,
analysis of the palace’s blueprints and the remaining elements of the decoration.
The ecclesiastical purpose of the surviving building of the “Demidoffs ex-chapel” has been
questioned and analyzed, based on D. Silvestri’s original sketches, from which it follows that
this is the building of the Odeon — a concert and theater hall. Particular attention is paid to
the carved decoration of the church, made in A. Barbetti’s workshop, to the iconostasis and
the gallery of local and small icons. Local icons of the iconostasis and icons of the apostles executed
in an academic manner by famous religious painter V. V. Vasilyev. However, the gallery
of small icons of the second tier of the iconostasis and the doors-kiots is stylistically close to
the icon-painting of the 17th century. Also, based on historical analysis and analysis of style,
the author sets up a hypothesis that the gallery of small icons from Demidoffs’ church belong
to “Nevyansk” or “Peshekhonovsk” icon-painting schools
Comparative study of magnetic beads and microplates as supports in heterogeneous amplified assay of miRNA-141 by using mismatched catalytic hairpin assembly reaction
No full textMagnetic beads (MBs) are often considered as an effective carrier in heterogeneous assays due to the simplicity of separation and washing, and the ability to increase and control the surface area. However, the effect of the MBs surface on the analytical parameters is poorly characterized and is often postulated from intuitive considerations. Herein, experimental evaluation through the comparison of MBs and microwell plate was carried out using the miRNA-141 (biomarker for cancer) as a target, the detection of which was performed by chemiluminescent assay with a homogeneous mismatched catalytic hairpin assembly (mCHA) reaction. The mCHA reaction produced double-stranded (ds) DNA labeled at one end with fluorescein (Flu) for capture with anti-Flu antibodies immobilized on a solid carrier, on the other end with biotin for recognition by streptavidin-polyperoxidase conjugate. The conditions of immobilization of anti-Flu antibody on MBs (a diameter of 440 nm) performed using a carbodiimide method were optimized by varying the antibody concentration in the reaction solution. It was shown that the dependence of chemiluminescent signal as a function of the concentration of anti-FluAb-MBs conjugates had a bell-shaped character. The maximum chemiluminescence was produced at the concentration of the conjugates of 2 × 109 particles/mL, with a surface area of 65 mm2. The identical surface area was used upon the assay performance with polystyrene microplates. Comparison of MBs- and microplate-assays for miRNA-141 determination showed that the obtained calibration curves and their detection limit values were the same and did not depend on the used carrier. The results showed that the choice of a carrier for heterogeneous assays should be guided by the convenience of the assay performance, not its surface area. © 2022 Elsevier B.V
Highly sensitive multiplex lateral flow immunoassay of phytopathogens using Au@Pt nanoparticles as the colorimetric and catalytic label
No full textA device for multiplex lateral flow immunoassay (LFIA) of major viral (potato viruses X and Y, potato leafroll virus) and bacterial (Ralstonia solanacearum, Clavibacter michiganensis, Dickeya solani, Pectobacterium atrosepticum) potato pathogens was developed. The device includes test strips connected with the central fiberglass reservoir. The addition of the probe (300 µL) to the reservoir initiates the migration of the liquid along membranes and the formation of immune complexes labeled with Au@Pt nanosized label. Besides the own Au@Pt coloration, the colorimetric signals are enhanced using the peroxidase-mimicking activity of Au@Pt. The developed device facilitated rapid (15 min), multiplex (7 targets), and highly sensitive LFIA for viral (330-480 pg/mL) and bacterial (500-104 cells/mL) pathogens. © 2021 Author(s)
Исследование биологической активности водорастворимого комплекса C60/поли-N-винилпирролидон
No full textObjectives. The study aimed to investigate the biological activity of the C60/poly-N-vinylpyrrolidone (C60/PVP) complex representing a water-soluble fullerene derivative. In vitro and in vivo techniques were used to analyze the effect of the C60/PVP complex on the activity of lactate dehydrogenase (LDH) and evaluate changes in the biochemical parameters of blood serum when per os administered to mice.Methods. In order to determine the activity of a commercial LDH preparation and study the kinetics of this process, the standard Warburg photometric method was used. To assess the effect of polyvinylpyrrolidone (PVP) and the C60/PVP complex on some biochemical parameters in vivo, a study was conducted on two-month-old male white mongrel mice weighing 20 ± 3 g. Determination of biochemical parameters of blood serum was carried out using a semi-automatic biochemical analyzer according to standard methods.Results. The effect of the C60/PVP complex on LDH activity was studied along with changes in the biochemical parameters of mouse blood serum characterizing carbohydrate metabolism. As well as increasing the glucose and pyruvic acid content, the C60/PVP complex was found to reduce lactate content and LDH activity in blood serum along with in vitro LDH activity according to the type of mixed inhibition.Conclusions. The C60/PVP complex and PVP were shown to exhibit biological activity in vitro and in vivo. The C60/PVP complex, representing a mixed-type LDH inhibitor, was shown to inhibit LDH activity, as well as contributing to a decrease in lactate concentration and an increase in the concentration of pyruvic acid and glucose in blood serum when administered per os to mice. The inhibitory effect of PVP on LDH activity was revealed in both in vivo and in vitro investigations. In vivo, PVP contributes to a decrease in the concentration of lactate in the blood. The less pronounced effect of the C60/PVP complex as compared to PVP alone may be due to the fact that C60 molecules are “hidden” in cavities formed in PVP molecules.Цели. Исследовать биологическую активность водорастворимого производного фуллерена – комплекса C60/поли-N-винилпирролидона (C60/ПВП) – в условиях in vitro и in vivo; изучить влияние комплекса C60/ПВП на активность лактатдегидрогеназы (ЛДГ) в условиях in vitro и in vivo; оценить изменения биохимических показателей сыворотки крови при введении мышам C60/ПВП per os.Методы. Для определения активности коммерческого препарата ЛДГ и исследования кинетики данного процесса был использован фотометрический метод Варбурга с применением стандартной методики. Для оценки влияния поливинилпирролидона (ПВП) и комплекса C60/ПВП на некоторые биохимические показатели in vivo было проведено исследование на двухмесячных самцах белых беспородных мышей весом 20 ± 3 г. Определение биохимических показателей сыворотки крови проводилось с помощью полуавтоматического биохимического анализатора по стандартным методикам. Результаты. Исследовано влияние комплекса C60/ПВП на активность ЛДГ и проведена оценка изменений биохимических показателей сыворотки крови мышей, характеризующих углеводный обмен. Установлено, что комплекс C60/ПВП увеличивает содержание глюкозы и пировиноградной кислоты, снижает содержание лактата и активность ЛДГ в сыворотке крови по сравнению с контролем, а также снижает активность ЛДГ в условиях in vitro по типу смешанного ингибирования.Выводы. Комплексы C60/ПВП и ПВП проявляют биологическую активность в условиях in vitro и in vivo. Установлено, что комплекс C60/ПВП является ингибитором ЛДГ смешанного типа в условиях in vitro, угнетает активность ЛДГ в условиях in vivo, а также способствует снижению концентрации лактата и увеличению концентрации пировиноградной кислоты и глюкозы в сыворотке крови при введении мышам C60/ПВП per os. При этом также выявлено ингибирующее действие и ПВП на активность ЛДГ in vitro и in vitro, причем в условиях in vivo ПВП способствует снижению концентрации лактата в крови. Менее выраженное действие комплекса C60/ПВП по сравнению с ПВП может быть связано с тем, что молекулы C60 «скрыты» в полостях, образованных в молекулах ПВП
